INFORMAL PUBLIC HEARINGS FOR THE PROPOSED RULE

ON OCCUPATIONAL EXPOSURE TO

RESPIRABLE CRYSTALLINE SILICA

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UNITED STATES DEPARTMENT OF LABOR

OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION

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March 20, 2014

9:30 a.m.

Frances Perkins Building Auditorium

200 Constitution Avenue, N.W.

Washington, D.C. 20210

BEFORE: 	DANIEL F. SOLOMON

	   	Administrative Law Judge

U.S. DEPARTMENT OF LABOR (DOL):

ALLISON KRAMER

Attorney, Office of the Solicitor

ANNE RYDER

Attorney, Office of the Solicitor

OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION (OSHA):

WILLIAM PERRY

Acting Director, Directorate of Standards and Guidance

TIFFANY DeFOE

Office of Chemical Hazards - Metals

PATRICIA DOWNS

Office of Technologic Feasibility

ANNETTE IANNUCCI

Health Scientist, Office of Chemical Hazards

- Non-Metals

ROBERT STONE

Director, Office of Regulatory Analysis - Health

DAVID O'CONNOR

Director, Office of Chemical Hazards - Non-Metals

JANET CARTER

Office of Chemical Hazards - Metals

STEPHEN SCHAYER

Office of Physical Hazards

ROBERT BURT

Acting Deputy Director, Directorate of Standards and Guidance

LYN PENNIMAN

Director, Office of Physical Hazards

PEER REVIEWERS:

BRIAN MILLER, Ph.D.

Institute of Occupational Medicine

GARY GINSBERG, Ph.D.

ANDREW SALMON, Ph.D.

KENNY CRUMP, Ph.D.

NATIONAL INDUSTRIAL SAND ASSOCIATION (NISA):

MARK ELLIS

President

ANDREW O'BRIEN, CIH

Vice President of Safety and Health

Unimin Corporation

JAMES CONRAD, JR.

Attorney, Conrad Law and Policy Counsel

INTERNATIONAL DIATOMITE PRODUCERS ASSOCIATION (IDPA):

MARK ELLIS

Executive Director

KENNETH MUNDT, Ph.D.

ENVIRON International Corporation

JAMES CONRAD, JR.

Attorney, Conrad Law and Policy Counsel

BRICK INDUSTRY ASSOCIATION (BIA):

ROBERT E. GLENN, M.P.H., CIH

ACME BRICK COMPANY:

DR. GARTH TAYLER

Technical Director

THOMAS BROWN

Director of Health and Safety

BILL LATHAM

General Counsel and Risk Manager

AMERICAN COLLEGE OF OCCUPATIONAL AND ENVIRONMENTAL MEDICINE (ACOEM):

MICHAEL FISCHMAN, M.D.

AMERICAN THORACIC SOCIETY (ATS):

ROBERT COHEN, M.D.

ASSOCIATION OF OCCUPATIONAL AND ENVIRONMENTAL CLINICS

(AOEC):

TEE GUIDOTTI, M.D.

AMERICAN PUBLIC HEALTH ASSOCIATION (APHA):

ROSEMARY SOKAS, M.D., M.S., MOH

INDIVIDUALS:

CELESTE MONFORTON, Dr.P.H., M.P.H.

KENNETH ROSENMAN, M.D.

DAVID F. GOLDSMITH, M.S.P.H., Ph.D.

JAMES CONE, M.D., M.P.H.OTHER PARTICIPANTS:

LAURA WELCH, M.D.

Building and Construction Trades Department, AFL-CIO

SCOTT SCHNEIDER, CIH

Director of Occupational Safety and Health

Laborers' Health and Safety Fund of North America

DAE WARD

Alabama Power

JIM WEEKS, Sc.D., CIH

Mine Safety and Health Administration

FRANK HEARL

Chief of Staff, NIOSH

DAVID WEISSMAN

Director, Division of Respiratory Disease Studies NIOSH

FRANKLIN MIRER, Ph.D., CIH

CUNY School of Public Health

AFL-CIO

NEIL KING

Attorney, American Chemistry Council's Crystalline Silica Panel

DARIUS D. SIVIN, Ph.D.

Health and Safety Department, United Auto Workers

ELIZABETH NADEAU

Attorney, International Union of Operating Engineers

RAMI KATRIB

Health, Safety and Environment Department

United Steelworkers Union

AVI MEYERSTEIN

Attorney, Jackson Lewis

U.S. Chamber of Commerce

BOVNAR ANAND, M.D.

INDEX

										PAGE

INTRODUCTION

Judge Daniel F. Solomon					  	   PAGEREF a1Solomon \h  559

NATIONAL INDUSTRIAL SAND ASSOCIATION (NISA)

	Mark Ellis							   PAGEREF b1EllisNISA \h  559

	Andrew O'Brien, CIH						   PAGEREF b2Obrien \h  563

	Questions							 	   PAGEREF b3questionsMonforton \h  586

INTERNATIONAL DIATOMITE PRODUCERS ASSOCIATION

(IDPA)

	Mark Ellis							   PAGEREF c1Ellis \h  617

	Kenneth Mundt, Ph.D.				  	   PAGEREF c2Mundt \h  621

	Questions							 	   PAGEREF c3qOsha \h  636

BRICK INDUSTRY ASSOCIATION (BIA)

	Robert E. Glenn, M.P.H., CIH			  	   PAGEREF d1Glenn \h  653

	Questions								   PAGEREF d2qbypublic \h  680

ACME BRICK COMPANY

	Dr. Garth Tayler						   PAGEREF F1Tayler \h  702

	Thomas Brown							   PAGEREF F2Brown \h  709

	Bill Latham							   PAGEREF F3Latham \h  715

	Questions								   PAGEREF F4questions \h  724

INDEX

										PAGE

AMERICAN COLLEGE OF OCCUPATIONAL AND

ENVIRONMENTAL MEDICINE (ACOEM); AMERICAN

THORACIC SOCIETY (ATS); ASSOCIATION OF

OCCUPATIONAL AND ENVIRONMENTAL CLINICS (AOEC);

and AMERICAN PUBLIC HEALTH ASSOCIATION (APHA)

	ACOEM - Michael Fischman, M.D. 			  PAGEREF G1Fischman \h  764

	ATS - Robert Cohen, M.D.					  PAGEREF H1Coeh \h  770

	AOEC - Tee Guidotti, M.D.				  PAGEREF I1Guidotti \h  780

	APHA - Rosemary Sokas, M.D., M.S., MOH		  PAGEREF J1Sokas \h  787

	Questions								  PAGEREF J2questions \h  794

INDIVIDUALS

	Celeste Monforton, Dr.P.H., M.P.H.		  PAGEREF k1Monforton \h  845

	Kenneth Rosenman, M.D.					  PAGEREF L1Rosenman \h  853

	David F. Goldsmith, M.S.P.H., Ph.D.		  PAGEREF M1Goldsmith \h  859

	James Cone, M.D., M.P.H.					  PAGEREF n1Cone \h  866

	Questions								  PAGEREF O1questions \h  873

ADJOURNMENT								  PAGEREF adjourn \h  904

EXHIBITS

EXHIBITS		DESCRIPTION				 	PAGE

Exhibit 13	Mr. Ellis' testimony, NISA	        PAGEREF Ex13 \h  585

Exhibit 14	Mr. O'Brien's testimony		   	   PAGEREF Ex14 \h  586

Exhibit 15	Mr. Ellis' testimony, IDPA	   	   PAGEREF ex15to17 \h  635

Exhibit 16	Dr. Mundt's testimony	   	  	   PAGEREF ex15to17 \h  635

Exhibit 17	IDPA PowerPoint 		   		   PAGEREF ex15to17 \h  635

Exhibit 18	Mr. Glenn's statement/PowerPoint	   PAGEREF Ex18 \h  680

Exhibit 19	Meyer study in CHEST	  		   PAGEREF Ex19 \h  686

Exhibit 20	Epstein article			  	   PAGEREF Ex20 \h  687

Exhibit 21	Castellan article			  	   PAGEREF Ex21 \h  687

Exhibit 22	Dr. Sokas' testimony		 	   PAGEREF Ex22 \h  844

Exhibit 23	Reserved - Dr. Cohen's testimony	   PAGEREF E23Cohenreserve
\h  844

Exhibit 24	Reserved - Dr. Monforton's

			testimony	 					   PAGEREF E24Montfortonreserve \h  896

Exhibit 25	Reserved - Dr. Rosenman's

			testimony	 					   PAGEREF E25Rosenmanreserve \h  903

Exhibit 26	Dr. Goldsmith's testimony		   PAGEREF Ex26and27 \h  904

Exhibit 27	Dr. Cone's PowerPoint			   PAGEREF Ex26and27 \h  904

P R O C E E D I N G S

(9:30 a.m.)

		JUDGE SOLOMON:  Let's go on the record.

		Ms. Kramer, do you want to enter your appearance for the record?

		MS. KRAMER:  Sure.  I'm Alison Kramer.  I am with the Office of the
Solicitor here at DOL.

		JUDGE SOLOMON:  So the first organization that will make a
presentation is the National Industrial Sand Association.  And,
Mr. Conrad, you're waving at somebody.  Who is going to start with the
presentation?

		MR. ELLIS:  I am.

		JUDGE SOLOMON:  Okay.

		MR. ELLIS:  Good morning.  I am Mark Ellis and I am President of NISA,
the National Industrial Sand Association.  I am joined this morning by
Andrew O'Brien, the Vice President of Safety and Health for Unimin
Corporation, a NISA member company, and Jamie Conrad, the principal of
Conrad Law and Policy Counsel, who is NISA's counsel in this rulemaking.

		NISA is a nonprofit, 501(c)(6) trade association representing major
North American producers and processors of industrial sand, sometimes
called silica sand.  NISA currently has 31 members and is the oldest and
largest trade association representing the industrial sand industry in
the United States and Canada.

		Industrial sand companies produce 100 percent pure crystalline silica.
 As a result, NISA members generally have longer history of working with
silica and more direct contact with silica than anyone else in industry.
 It is also why beginning in the 1970s, NISA and its member companies
developed what has now become known as the NISA Silicosis Prevention
Program, or SPP.

		NISA members' workplaces are predominantly mining operations and thus
are typically regulated by MSHA and not OSHA for purposes of
occupational safety and health.  NISA has a substantial stake in the
outcome of the OSHA crystalline silica rulemaking, however, for several
reasons.  The most important of these reasons is simple, however.  NISA
members strongly believe that the exposure monitoring and medical
surveillance that they implement under the Silicosis Prevention Program
are the right things to do to prevent health -- protect the health of
their employees and are good for their business' bottom lines.  They
also believe these two practices must be included in a comprehensive
OSHA standard.

		NISA is pleased to offer a unique perspective on the issue of
workplace exposure to crystalline silica and an optimal solution to
challenge -- to the challenge facing OSHA.

		As we explained in our comments, NISA strongly supports what has come
to be termed the NISA solution, a comprehensive standard that would
require exposure monitoring and medical surveillance at an action level
of 50 µg/m3, while maintaining the current permissible exposure limit,
or PEL, at 100 µg/m3.  This is similar to OSHA's Alternative 1.  And
NISA commends OSHA for offering that alternative first and for stating
that it will, quote, "Strongly consider alternatives that would reduce
the economic impact of the rule," close quote.

		As our comments demonstrate, the NISA solution would substantially
reduce any risk of material impairment from workplace exposure to
crystalline silica rising from the stubbornly high level of
noncompliance with the current PEL.

		The NISA solution is also economically and technologically feasible.
The beauty of the NISA solution lies in two concepts that OSHA itself
has seen the extraordinary value of over the years, a potentially
achievable action level and a substance-specific standard.

		First, a potentially achievable action level drives companies that can
need it to lower their exposures to a level that removes them from the
burden of complying with the regulation altogether.  We believe that
positive enticement is a more powerful motivation than the negative
enticement of avoiding an OSHA citation.

		If the action level were set at 25 µg/m3, few if any companies would
be able to achieve that mark.  Most would devote expenditures and
resources sufficient just to comply with the PEL, and many would only
spend enough not to violate it by much or very often.

		A potentially achievable action level, however, will drive companies
that can meet it to pay what they might call a regulatory avoidance
premium to avoid having any further compliance obligations under the
rule.  A potentially achievable action level is paramount in making this
rule successful.

		Further, not enough has been said about the simple power of OSHA's
substance-specific standards, of which there are only about 30.  Once
crystalline silica has a dedicated standard, a great deal more attention
will be given to controlling what potential hazard this substance may
present in the workplace, and this will occur no matter what the
exposure level is established.

		The NISA solution plays on the power of the action level and the
substance-specific standards and presents a pragmatic and cost-effective
alternative that should be embraced by labor, industry, and OSHA.

		NISA's principal witness today, Andrew O'Brien, is chair of NISA'S
Silica Health Effects Committee.  He, thus, is ideally positioned to
describe the NISA Silicosis Prevention Program and the extraordinary
results that it has produced.  That experience is what makes us so
confident in saying that OSHA could retain the current PEL and still
eradicate new cases of silicosis.  The key is to include exposure
monitoring and medical surveillance triggered by an action level in a
comprehensive standard.

		Mr. O'Brien also will discuss the silica epidemiology study that NISA
is sponsoring and that could have a profound effect on this rulemaking.
So with that introduction, I'd like to turn things over to Mr. O'Brien.

		MR. O'BRIEN:  Thanks, Mark.  Good morning.  My name is Andrew O'Brien,
and I am Vice President of Safety and Health for Unimin Corporation.  I
am pleased to testify before you this morning on behalf of NISA
concerning OSHA's proposed rule regarding crystalline silica.

		As Mark just noted, NISA and its member companies strongly support the
promulgation of a crystalline silica rule that requires exposure
monitoring and medical surveillance at the action level of 50 µg/m3,
while retaining the current permissible exposure limit of 100 µg/m3.

		The focus of my testimony this morning will be twofold.  First, I will
testify regarding NISA's groundbreaking Silicosis Prevention Program, or
SPP, and the profound effect the SPP has had in eliminating the
occurrence of new cases of silicosis in NISA member company workplaces.
The SPP includes both exposure monitoring and medical surveillance and
the results of the SPP, as shown by annual company reporting within the
association, provide clear support for including both of these practices
as ancillary provisions in a comprehensive OSHA crystalline silica
standard.  I will also comment briefly on the economic feasibility of
exposure monitoring and medical surveillance.

		Second, I will testify regarding a major epidemiological study that
NISA has commissioned and that is ongoing as we speak.  We expect that
this study will make a substantial contribution to the existing body of
science that exists to date regarding the shape of the dose-response
curve for silicosis in large part because of the extensive data
available for this study, as I will discuss.  We urge OSHA to
incorporate the results of this study in its decision-making process for
the final rule.

		But, first, let me provide some background on myself and Unimin.  I am
a certified industrial hygienist and a certified safety professional
with a master of science degree in industrial hygiene and an
undergraduate degree in safety engineering.  I am currently the Vice
President of Safety and Health for Unimin Corporation.  Founded in 1970,
Unimin has grown from a small local sand mining company to become a
leading producer of nonmetallic industrial minerals in the worldwide
Sibelco Group.

		We are the largest producer of industrial sand in each of the United
States, Canada, and Mexico, and along with our affiliates in other
countries, we are the largest producer in the world.  Our products are
the fundamental building blocks of nearly every manufacturing process --
sorry, manufacturing and industrial process.  We are a worldwide
supplier to the glass, ceramic, and lighting industries; to oil and
natural gas service companies; and to paint, plastic, rubber, and
composite manufacturers.

		Our high purity quartz products are the starting point for the world's
semiconductor and solar photovoltaic cell production.  We are also an
integral supplier to the metallurgical and foundry industries, and we
participate in a wide range of civil, industrial, environmental, and
building related applications.  Our products touch the lives of millions
of people daily.

		In my current capacity at Unimin, I am responsible for the safety and
health of Unimin's employees throughout North America, with a current
census of approximately 2,400.  Within this capacity lies Unimin's
occupational health program, which has a significant emphasis on the
prevention of new cases of silicosis.  Routinely quantifying employee
exposure to respirable crystalline silica and regularly conducting
medical surveillance programs are the backbone of Unimin's efforts to
prevent new cases of silicosis.

		Unimin has been a proud member of NISA since 1970.  Unimin has always
believed strongly in NISA's mission.  And Unimin employees have
historically had leadership positions within NISA.  Three of NISA's past
chairmen have been Unimin executives, and a fourth is currently on
NISA's executive committee.  And, as Mark noted, I am chair of NISA's
Silica Health Effects Committee and chair of the Safety and Health
Committee for NISA's umbrella organization, the Industrial Minerals
Association North America.

		The NISA silica health effects committee is responsible for continuing
to steward the NISA Silicosis Prevention Program and for facilitating
the conduct of our ongoing epidemiology study in collaboration with
NISA's epidemiology research task force.  Coordinating efforts among
government and industry representatives, the NISA silica health effects
committee was also largely responsible in facilitating development and
publication of NIOSH's RI 9689, entitled Dust Control Handbook for
Industrial Minerals, Mining, and Processing.

		I am happy to be able to testify today about both the NISA Silicosis
Prevention Program and our epidemiology study and their potential
implications for this rulemaking.  As Mark Ellis explained, the
industrial sand companies produce essentially 100 percent pure
crystalline silica.  As a result, NISA members have generally had longer
histories of working with silica, more direct contact with silica, and
greater challenges due to the 100 percent silica content of our products
than anyone else in industry.

		It is also why, beginning in the late 1970s, NISA and its member
companies reached out to occupational health experts to establish a
voluntary program of employee exposure assessment and medical
surveillance.  The program referred to as the Occupational Health
Program for Exposure to Crystalline Silica in the Industrial Sand
Industry, or OHP, is the basis for the SPP.

		In 1993, the NISA board of directors adopted the goal of preventing
any new cases of silicosis among their employees, with "new" defined as
cases of silicosis produced by exposures at NISA member company
workplaces commencing in 1994.  This definition of "new" recognized that
some number of NISA member companies -- NISA member company employees
might have had silicosis at that time or might subsequently develop it
based on exposures occurring before that date, whether at NISA member
companies or elsewhere, or after that date but before employment at a
NISA member company.

		As a result of this decision and influence by the widespread
establishment of management system approaches, NISA and its members
subsequently incorporated the OHP into a broader Silicosis Prevention
Program.  I'll discuss these two programs in reverse order.

		The scope and elements of the SPP are set out in this guide right
here, excuse me, which is entitled, National Industrial Sand Association
Silicosis Prevention Program, which NISA included as an appendix to its
comments.  The SPP declares "NISA's expectation that all member
companies will implement and manage a comprehensive silicosis prevention
program at all worksites sufficient to eliminate silicosis among its
employees."

		The SPP currently comprises seven steps:

		First, strong management commitment to implement a silicosis
prevention program.  This commitment includes not only a commitment to
performing both dust exposure assessment and medical surveillance, but
to sharing data on both dust measurements and chest x-ray results with
other NISA member companies at annual benchmarking sessions.  I'll turn
to that data-sharing process in a moment.

		Second, implementation of the OHP.  The OHP describes in great detail
how respirable crystalline silica exposure monitoring and medical
surveillance are to be conducted by NISA members.

		Third, periodic assessments to quantify worker exposure to respirable
crystalline silica dust.  As the SPP states, it is crucial that NISA
member companies implement and manage a silica exposure program to
collect personal breathing zone samples from all employees exposed to
industrial sand so that periodic measurements of silica exposure and
cumulative exposure assessments can be made.  After all, if you are not
quantifying employee exposure, how do you know whether or not you are
adequately controlling employee exposure?

		Fourth, routine medical surveillance to assess worker health and to
look for indications of silica-related health effects.  The SPP explains
that medical surveillance serves multiple purposes.  It establishes a
baseline for future measurements so that each employee serves as his or
her own control.  It allows detection of abnormalities that might be
consistent with the health effects of silica exposure at an early age --
sorry, early stage when intervention can lead to the prevention of
disease progression.

		It prevents the development of silicosis that could produce pulmonary
impairment in the worker.  It prevents the development of other
occupational conditions that might be associated with exposure to
silica.  It enables disclosure to the worker of occupational and
non-occupationally related abnormalities for appropriate medical
follow-up.  And it leads to the development of a database on which
epidemiological studies of crystalline silica exposure can be based.

		The fifth element of the SPP is implementation of dust control
equipment or processes.  The SPP encourages NISA member companies to
undertake a program to anticipate, recognize, evaluate, and control
hazardous dust exposures, and to continually monitor the effectiveness
of control strategies.  It emphasizes that the control of hazards from
exposures to respirable crystalline silica and the elimination of
silicosis is the primary and single most important reason for developing
a comprehensive silicosis prevention program.

		The sixth element is employee involvement in all stages of SPP
implementation.  The SPP recognizes that, in quotes, "A workforce fully
involved in health and safety management, and a system of workers
operating in partnership with management are essential parts of an
effective health and safety program," close quote.  It describes steps
for promoting employee engagement and provides example actions
management can take.

		The seventh element is smoking cessation programs.  The principal goal
of such programs is to reduce the added impact of smoking on
silica-related health effects.  A related goal is to diminish the
serious adverse health effects that are directly caused by smoking and
exposure to secondhand smoke.

		Of the seven elements of the SPP, the two that are most relevant to
this rulemaking are also the historic core of the SPP, regular personal
sampling of employees' exposure to respirable crystalline silica and
periodic medical surveillance.  The details of these two elements are
spelled out in the current NISA occupational health program on which the
SPP is based, which we also included as an appendix to our comments.

		The OHP begins with an overview of the state of the science regarding
the range of potential health effects of silica exposure.  It then
provides detailed guidance on both dust sampling and medical
surveillance.

		With respect to dust sampling, the OHP's goal is to provide sufficient
detail in sufficiently clear terms that a, quote, "safety officer,
laboratory technician, quality analyst, or any person within a company
who has responsibility for the industrial hygiene program can collect
sufficient personal breathing zone samples from all employees exposed to
industrial sand so that cumulative individual exposure assessments can
be made," end quote.

		Importantly for this rulemaking, what the OHP and our experience show
is that companies don't need to hire outside contractors to competently
conduct exposure monitoring.  Company staff can be trained to do it and
do it competently.  I'll come back to this point in a moment.

		On the subject of medical surveillance, the OHP provides guidance for
both baseline and periodic medical surveillance of employees.  While it
is principally intended for health professionals, it is also written for
any member company employee with responsibility for a safety and health
program since such individual should have a working knowledge of the
elements of the medical surveillance program.

		Multiple citations to the OHP manual in the preamble confirm the
obvious fact that OSHA's proposed medical surveillance requirements are
substantially derived from NISA's OHP manual.  NISA is proud of these
references and appreciates being able to provide a model for such an
important element of silica workplace health.

		Now that I have described what the SPP is, I'd like to turn to what it
has accomplished.  As I mentioned a moment ago, part of the management
commitment that is Step 1 of the SPP is a commitment to sharing data on
both exposure measurement and chest x-ray results with other NISA member
companies at annual benchmarking sessions.  These annual sessions have
occurred every year since 1994.  Each year, SPP participating members
report employee personal dust sampling and chest x-ray data for the
previous year to NISA's staff.  That information is compiled by NISA
staff under my committee's direction.  I then present the information on
a blinded basis to the membership at a special session at the annual
meeting.

		In these annual reports, respirable crystalline silica exposure data
are presented for the SPP participants as a whole, as well as for
individual company participants.  Information such as the number of
measurements, average percent quartz, and average percent exposure as a
percentage of the PEL for 10 different processes, for example, mining,
bagging, screening, are included in this reporting.

		JUDGE SOLOMON:  Could I stop you for a second?  You're about 20
minutes into about a 30-minute presentation.  And we have, I'm sure
we're going to have some questions.  So could I get some sense, first of
all from the peers here, are you going to ask questions?  I'm not seeing
any hands.

		And from the public, are there -- okay, so there are several people
who want to ask questions.

		MR. CONRAD:  Judge, I just might note in contrast to the last two
days, there are about 110 minutes allocated for presentations today.
There is another 40 minutes this morning that is not allocated for any
purpose.

		JUDGE SOLOMON:  We were talking -- well, one of the problems is that
we have been running long.  And among ourselves we've been talking about
the fact we probably have to go into the lunchtime.  We probably won't
be finished until about 12:30.

		MR. CONRAD:  Oh, I'm thinking today we may finish early, if anything.

		JUDGE SOLOMON:  Well, what can I say?  That's not the consensus on the
left side of the podium anyway.

		MR. CONRAD:  No.  I mean we're just getting to the good part.  That's
my concern.

		JUDGE SOLOMON:  Okay.  So are we going to be able to get to some
questions?

		MR. CONRAD:  Counselor?

		MS. KRAMER:  Your Honor, we're happy for them to finish their
presentation, assuming they are going to wrap it up in the next 10
minutes that they have been scheduled for.

		MR. CONRAD:  That's fair.

		JUDGE SOLOMON:  Okay.  Are we going to be able to take questions from
the audience?

		MS. KRAMER:  I believe so, yes, sir.

		JUDGE SOLOMON:  All right.

		MR. CONRAD:  Thank you.

		MR. O'BRIEN:  Chest x-ray data are presented within the annual report
as the number of individuals per company with chest x-rays classified as
having a profusion rating of greater than or equal to 1/1 on the ILO
scale.  Those x-rays are generally read by more than one certified B
reader in accordance with the OHP's consensus reading process.  These
presentations allow the membership to evaluate how they are doing
individually and comparatively at controlling exposures and eliminating
new cases of silicosis.  They also allow NISA to assess the
effectiveness of the SPP.

		A total of 11 companies have reported chest x-ray data since 1994.
Over this 19-year period, medical surveillance at these companies has
yielded a total of 8 cases with radiographic evidence of silicosis.
Again, that means greater than or equal to 1/1 on the ILO scale.  Those
eight cases have occurred at a total of three companies.  Those three
companies advise NISA that they do not regard these as new cases,
meaning that in each case the company determined that the silicosis was
attributable to exposures occurring either before 1994, either at the
company or elsewhere, or after that date but before employment at the
company.

		I should note that several NISA members have grown substantially by
acquisition in the past two decades.  The acquired companies typically
had not implemented exposure monitoring, medical surveillance, or other
elements of the SPP, although that certainly changes once they got
folded into the acquiring company.  It is not surprising, therefore,
that along with those new acquisitions, NISA members have inherited
cases of detectable or insipient silicosis.

		Let me pause for a minute to repeat our findings.  A total of 11 NISA
members over a period of 19 years have found 8 cases of silicosis, none
of which were new.  In other words, implementation of the SPP by
participating companies has eliminated the creation of new silicosis
cases amongst those companies' employees, even as those companies were
subject to the current PEL of 100 µg/m3.

		We recognize that silicosis, while dramatically reduced, is still
being diagnosed elsewhere around the country.  NISA believes that this
disease is caused by the persistently high rates of noncompliance with
current PEL -- with the current PEL that OSHA continues to witness
despite years of focused enforcement.  We further believe that the
absence of an exposure assessment requirement from the current
crystalline silica PEL is the principal reason for this widespread and
often severe noncompliance.

		This conclusion is supported, by the way, by a study of Industrial
Minerals Association-Europe initiative described in our comments, which
found that the exposure monitoring with feedback to the affected
worksites produced a two to threefold reduction in exposure
concentrations.  Quantification of exposure via personal dust sampling
of employees is, thus, key to ensuring compliance with any PEL for
crystalline silica.

		NISA, therefore, supports OSHA's proposed inclusion of exposure
monitoring, as well as medical surveillance as part of a comprehensive
crystalline silica standard.  We believe that the NISA solution, the
current PEL, supplemented by exposure assessment and medical
surveillance triggered at 50 µg/m3 action level should reduce
significant risk of material health impairment for silicosis sufficient
to meet the requirements of Section 6(b) of the OSHA Act.

		Unimin has found that the cost of conducting exposure monitoring and
medical surveillance are quite minimal.  These costs, in fact, are
considered insignificant within our company.  We included actual cost
data for five NISA member companies in our comments on Page 24.  The
real cost impact of the proposed rule will be driven by the engineering
controls required to achieve the lower PEL where that can be done.

		But I do want to highlight one way in which OSHA has overstated the
cost of exposure monitoring in our view.  In its cost analysis, OSHA
assumes that employers will use outside contractors to conduct initial
and periodic exposure assessments.  As I mentioned earlier, NISA's
member companies conduct exposure assessments using in-house personnel.
Obviously, no one can say for certain what the broad variety of
industries covered by OSHA's proposed standard for general industry
would do in response to an exposure-monitoring mandate.

		Clearly, activities involving potential crystalline silica exposures
are absolutely central to what NISA members do, whereas such activities
may be more or less tangential for other regulated industries.  Also,
NISA members have been doing exposure assessment under the SPP since the
1970s, so they have developed substantial expertise in how to do it cost
effectively.  Nonetheless, we believe that some percentage of
OSHA-regulated establishment can and will internalize the function
either at the outset of the rule's effectiveness or as they gather
experience under the rule.

		We do not believe this issue is purely one of business or
establishment size.  Many NISA member companies are small businesses.
They have nonetheless found that it is more cost effective for them to
train particular staff and acquire the relevant equipment than it is to
hire consultants.  As I explained earlier, our OHP document provides
sufficient detail in sufficiently clear terms that a safety officer,
laboratory technician, quality control analyst, or any person within a
company who has responsibility for the industrial hygiene program can
collect sufficient personal breathing zone samples from all employees
exposed to industrial sand so that cumulative individual exposure
assessments can be made.  We post the OHP on our website and so that
learning is available for companies to view.

		Given our experience, we urge OSHA to analyze scenarios in which some
percentage of regulated establishments do their own exposure
assessments.  We also urge OSHA to use the data that NISA supplied.
Three of the five companies included in our sample are among the largest
NISA members on a revenue basis, but another meets the SBA's size
standard for a small business.

		The last topic I'd like to address today is NISA's ongoing silica
silicosis dose-response study.  While the association between silicosis
and exposure to respirable crystalline silica is indisputable, there is
still considerable uncertainty regarding the dose-response relationship
of this association, particularly in the case of chronic simple
silicosis, which is the most common form of silicosis.

		It is unclear, for example, whether there is an effect threshold or
whether, instead, the dose-response curve is linear, even at the lowest
doses.  The slope of that curve is also uncertain.  As a result, there
is uncertainty regarding the degree of risk remaining at various
eight-hour, time-weighted average exposures, including most importantly
the current PEL of 100 µg/m3.  In NISA's view, this degree of
uncertainty is unacceptable for a rulemaking of this magnitude.

		NISA believes that regulatory standard setting ought to be based on
high quality, reliable science.  This is especially true where data of
sufficient quality and quantity exists to produce that science.

		The principal shortcoming affecting the vast majority of published
studies of silicosis risk is the reliance on poor quality or uncertain
exposure measurements.  This undermines the reliability of any
quantitative risk estimates based on those studies, including OSHA's.

		Many silicosis studies were based on very high exposure to quartz and
lack data on low exposures, so that estimated dose-response conclusions
have to be extrapolated to low doses.  Others lack data for early
exposure years, and so early exposures are based on inferred or
extrapolated concentrations.  Others are based on area sampling, rather
that personal sampling.  Even those that include personal dust sampling
of individuals generally involve measurements taken using the obsolete
particle count approach for all or part of the period evaluated.

		This latter defect is a serious limitation because it has become
increasingly clear that there is no single defensible conversion factor
from particle count measurements to gravimetric measurements.  No
published study involves so much exposure data, collected rigorously and
consistently via personal samplers, and evaluated gravimetrically with
percentage quartz assessed with x-ray diffraction.

		On the other hand, NISA's two largest member companies, Unimin and
U.S. Silica, possess an extensive database comprising decades of
gravimetric dust sampling and chest x-ray data generated by those
companies' implementation of the SPP.  The exposure data include about
50,000 dust measurements collected systematically since the mid-1970s,
with personal identifiers that will facilitate construction of a job
time exposure matrix.  These exposure samples encompass a large number
of job positions with low to high concentrations, which should ensure a
wide range of exposures for analyses of exposure response.

		Measurements are all reported gravimetrically with a quartz analysis
by x-ray diffraction.  The chest x-ray data similarly encompasses
thousands of chest x-rays generally taken at the beginning of the
individual's employment in the industrial sand industry and every two
years thereafter.

		JUDGE SOLOMON:  Okay, I'm sorry I have to butt in, but you're going to
have to wrap it up.  We're actually over a couple of minutes.

		MR. CONRAD:  Maybe you can answer the -- well, answer it in response
to questions.

		MR. O'BRIEN:  Yeah, let's go to questions.

		MR. ELLIS:  Maybe we can just cover the rest of it in response to
questions.

		JUDGE SOLOMON:  Okay.

		MR. ELLIS:  Your Honor, I think that one thing that we can do is we
can ask that our written testimony be entered into the record.

		JUDGE SOLOMON:  I was going to ask Mr. Conrad if he had any exhibits
he wanted to mark and offer.

		MR. CONRAD:  I think we have some copies of that.

		MR. ELLIS:  I have it right here.

		MR. CONRAD:  What else is in here?  Have you got it?

		JUDGE SOLOMON:  Okay.  So how are these going to be marked?

		MS. KRAMER:  It looks like this is Mr. Ellis' testimony on top,
followed by Mr. O'Brien's.  Your Honor, we'd like to mark Mr. Ellis'
testimony as Hearing Exhibit 13 and have it be admitted into the record.

		JUDGE SOLOMON:  Okay, without objection, so admitted.

(Whereupon, the document referred to as Hearing Exhibit 13 was marked
and	 received in evidence.)

		MS. KRAMER:  And Mr. O'Brien's written testimony as Hearing Exhibit
14.

		JUDGE SOLOMON:  And that is admitted also.

(Whereupon, the document referred to as Hearing Exhibit 14 was marked
and received in evidence.)

		MS. KRAMER:  Great.

		JUDGE SOLOMON:  Okay.  Ma'am, would you state your name for the
record, please, and spell your last name?

		DR. MONFORTON:  Dr. Celeste Monforton, M-o-n-f-o-r-t-o-n.

		JUDGE SOLOMON:  Okay.  And what do you do for a living?

		DR. MONFORTON:  I am a professorial lecturer at George Washington
University School of Public Health.

		JUDGE SOLOMON:  Are you representing anybody?

		DR. MONFORTON:  No, myself.

		JUDGE SOLOMON:  Okay, go ahead.

		DR. MONFORTON:  Mr. Ellis, the SPP has been recognized as a model and
in place for decades, and I commend the silica sand industry for having
that.  Are you aware of any other industries that have a comparable
program?

		MR. ELLIS:  Not to my knowledge.  I think that NISA and the Silicosis
Prevention Program that we operate under and have for decades really
serves as a model.  NISA, in effect, is the poster child for
implementation of the OSHA compliance standard, you know, the
comprehensive standard.  So I think we are unique in that, and we serve
as a model for others as to what we -- what can be accomplished.

		DR. MONFORTON:  Thank you.  Mr. O'Brien, when did the study you
referred to commence?

		MR. O'BRIEN:  It commenced during 2013, fall of 2013, and we
anticipate it being completed during the second to third quarter of
2015.

		DR. MONFORTON:  Okay.  And would you share with us the names and
affiliations of the individuals who peer-reviewed the protocol?

		MR. O'BRIEN:  I can't give you them specifically.  I know NIOSH was
one of the peer reviewers.  They provided over 100 comments on our
protocol.  I can't recall any other specifics.  That was the important
one.

		MR. ELLIS:  No, I mean I think we provided the protocol to NIOSH just
to verify that we were on the right approach.  As Andy said, we received
over 100 comments, and those were responded to by the investigators.

		MR. O'BRIEN:  It was seven different NIOSH scientists.

		DR. MONFORTON:  Thank you.  At what stage in the NISA protocol are you
at this point?

		MR. O'BRIEN:  I would say we're roughly a quarter of the way through
the protocol cases.  We're in the case identification stage right now,
soon to be moving onto the control identification stage.

		DR. MONFORTON:  Do you recall what the minimal period of follow-up is
for the cohort?

		MR. O'BRIEN:  The inclusion criteria was at least 10 years of
exposure.

		DR. MONFORTON:  And will you be looking at other silica-related
illnesses besides silicosis?

		MR. O'BRIEN:  No.

		DR. MONFORTON:  You answered that one.  With the --

		JUDGE SOLOMON:  Anything else?

		DR. MONFORTON:  One question.  With the SPP, can you describe the
process for notifying workers if they have silicosis or other
silica-related diseases?

		MR. O'BRIEN:  Yeah, I do it personally.

		DR. MONFORTON:  Okay.

		MR. O'BRIEN:  I conduct a videoconference or a face-to-face meeting
with the individual, cover the ILO form that has been completed by the B
reader, explain the legal obligations we have with respect to reporting
to the regulator and worker compensation systems, and benefits that are
available to them.

		DR. MONFORTON:  Okay, thank you.

		MR. CONRAD:  I note the protocol is an attachment to our comments, so
hopefully it's on the   HYPERLINK "http://www.regulations.gov/"
regulations.gov  now.

		DR. MONFORTON:  Thank you.

		JUDGE SOLOMON:  Next?  State your name and spell your last name,
please.

		DR. WELCH:  Laura Welch, W-e-l-c-h.  I'm an occupational physician
with the Building and Construction Trades of the AFL-CIO.  I've got a
lot of questions, but just I'll do in order of what I think I want to
hear the answer to the most.

		So I understand with the current case collection that's ongoing now
where you identify them as a 1/1 film and you said there were no new
cases, but the way I figure it, the latency for cases, you are now at 19
years or 20 years, because exposure had to begin in 1994.  Exposure
before that was excluded.  I just wanted to clarify that because that's
a relatively short latency period to be assured that you don't have
cases at your current exposure control.

		MR. O'BRIEN:  Correct.  The cases we're identifying or the cohort is
anyone regardless of when they started or stopped working for Unimin or
U.S. Silica and met the inclusion criteria.  So employees that may have
started in the '60s would be included in the cohort itself, not from
1994 forward.

		DR. WELCH:  But you said that the eight cases that have been
identified were considered to be not new cases.

		MR. O'BRIEN:  Those are eight cases identified by the member companies
and reported to NISA staff, not -- we're talking two different things.

		DR. WELCH:  Right, right.  No, that's what I wanted to know, because
you were saying that you're controlling to 100, a level of 100, and you
think that's sufficient to prevent new cases of silicosis.  But my
understanding is that is based on only 20 years of follow-up because you
identified the exposure for defining a new case of silicosis among the
member companies, not part of your study, as beginning in 1994.  If
someone came in, had exposure prior to that where the exposures may have
been higher, you didn't want to include them in that assessment?

		MR. O'BRIEN:  Well, the NISA board established that cutoff at 1994, so
the declaration of no new cases, correct, is from that date forward.

		DR. WELCH:  Right.  So I just wanted to clarify it's really 20 years
ago.

		MR. ELLIS:  Maybe to just supplement that, it's an ongoing program.

		MR. O'BRIEN:  Right.

		MR. ELLIS:  We hope to be doing this 20 years from now.

		DR. WELCH:  Right, right.  Okay, great.  The only other thing I
noticed about that, that your case collection and the way you are
reporting it annually is that you used a criteria of 1/1 on the film,
but in your cohort study that you are proposing you are using 1/0.

		MR. O'BRIEN:  Correct.

		DR. WELCH:  Which I think means you would agree with me that 1/0 is a
more sensitive indicator.  Have you had your member companies look to
see if they have identified any 1/0 films, or are you really restricting
it to the 1/1?

		MR. O'BRIEN:  Not as part of the -- not as part of the NISA SPP
reporting process.  You know, and a comment on 1/0 versus 1/1.  My
experience has shown that at the very low profusion levels, x-ray
quality has a huge impact on whether or not disease is detected or is
detectable.  And so I believe that using 1/1 is appropriate given the
fuzziness of the science of B reading at 1/0.

		DR. WELCH:  Okay.  Well, I won't -- I won't ask you more about that.
I don't agree.  But then, you know, in your current program, and I
should have echoed what Celeste had said, you know, I think your written
comments were great.  You've got some great comments on competent person
and a lot of things that I would say the Building Trades agrees with
some of the points that you made.

		I was curious, in your surveillance program, if you identify -- if a
medical exam identifies an individual with early changes of silicosis,
however you are defining it, what do you do?  Do you change your control
strategy?  Do you change the job for that worker?  What kind of changes
do you make?

		MR. O'BRIEN:  You know, we have an administrative control program that
looks at their current jobs, what the exposures are for those types of
jobs, whether they can be moved into a job with a lower expected
exposure level.  It's just a systematic review of what they are doing
and how we can better protect them moving forward in order to ensure
that there is no progression.

		DR. WELCH:  Okay.  And do you know, I know your program is voluntary
for the medical surveillance.  Do you have an idea of what proportion of
your employees participate?

		MR. O'BRIEN:  Within Unimin, at our silica processing facilities, it's
actually a condition of employment.  If you are going to work at one of
our facilities, you will participate in the program, so it's 100 percent
participation.

		DR. WELCH:  Okay.  So then it's not fair to call it voluntary.  I mean
voluntary in that they don't have to work there.

		MR. O'BRIEN:  The Unimin program, as far as the medical surveillance
at our industrial sand facilities, is not voluntary.

		DR. WELCH:  Okay, okay.  And then --

		JUDGE SOLOMON:  How much more do you have?

		DR. WELCH:  Well, I had just one question about your study, which has
an enrollment criteria of at least 10 years of exposure, which is then
10 years of latency, essentially.  Do you have any mechanism to provide
x-rays for workers who have left employment, so you could catch
individuals with longer latency down the road?

		MR. O'BRIEN:  We do not, no.

		DR. WELCH:  And do you have any idea what the average latency is of
the group that you have enrolled in the cohort?

		MR. O'BRIEN:  I do not, no, not at this point.

		DR. WELCH:  Okay.  All right, well, thank you.

		MR. O'BRIEN:  Thank you.

		JUDGE SOLOMON:  Okay, state your name and spell your last name.

		MR. SCHNEIDER:  Okay.  It's Scott Schneider, S-c-h-n-e-i-d-e-r.  I'm
with the Laborers' Health and Safety Fund of North America.

		I had a couple of questions.  One of the things is during your
testimony you described the stubbornly high level of noncompliance.  Are
you basing that on the IMIS data, the OSHA, that 30 percent was over --

		MR. ELLIS:  Yeah, correct.

		MR. SCHNEIDER:  So you're assuming that the IMIS data is somehow
representative of the industry, right?

		MR. ELLIS:  You know, I think that we take that data for what it has
said.  We've seen it portrayed graphically showing several decades and
showing essentially 30 percent noncompliance regardless of what decade
is looked at.

		MR. SCHNEIDER:  Right.  So if OSHA, I mean that's -- I mean if OSHA
were randomly inspecting workplaces, I guess you could say that might be
representative.  But if OSHA was targeting high exposure workplaces,
then that 30 percent might be not representative of the entire industry,
correct?

		MR. ELLIS:  Yeah, I mean if --

		MR. SCHNEIDER:  Okay.

		MR. ELLIS:  -- compliance, if it was targeted, would potentially be
different than a general industry survey.

		MR. SCHNEIDER:  Right, right.

		MR. CONRAD:  But presumably they are looking at the workplaces with
the most exposure to silica.  So they're probably looking at the places
where you would be most concerned about.

		MR. SCHNEIDER:  Right.  Well, they have the site-specific targeting
program where they're trying to go after employers who have the highest
potential for violations, okay.

		In terms of your exposure measurement, I know you do thousands of
exposure measurements, which is really great and I am very impressed.
Do you have -- have you entered into the record any information about
what percentage of them were below 100 µg or below 50 µg?

		MR. ELLIS:  No.

		MR. SCHNEIDER:  Okay.  And do you have that information?  Could you
supply that to OSHA?

		MR. ELLIS:  No.  I mean the samples that are collected are the
business of the companies that collect them.  So the association really
doesn't have access to those and can't make them available.

		MR. SCHNEIDER:  But you have summary statistics, though, right?

		MR. ELLIS:  Again, we blind those statistics when the companies report
it.  It's part of what we do to encourage them to participate in the
program.

		MR. SCHNEIDER:  Previously, yesterday, there was some discussion about
how employers claim that in order to assure that they are below a
certain level, like the 100 µg level, they have to control to the
action level, to half of that.  So is that true with NISA companies that
you guys are controlling down to 50 µg to make sure you don't get over
100?

		MR. O'BRIEN:  Well, certainly, within Unimin, we have an internal
target of 50 µg/m3 for a time-weighted average.  And we control to at
least below that in order to ensure the lowest likelihood of exceeding
100.

		MR. ELLIS:  I think that's also part of the rationale for the NISA
solution of maintaining the current PEL and yet instituting exposure
monitoring and medical surveillance at an action level of half that,
knowing that people would have to be below the PEL consistently to make
sure that they don't exceed it on any given occasions.

		JUDGE SOLOMON:  Do you have any more questions?

		MR. SCHNEIDER:  Yeah, one last question.  So if you are controlling
down to 50 µg regularly, then the study that you're looking at is not
going to really look at the dangers of 100 µg exposures.  It's really
more looking at the dangers at 50 µg.

		MR. O'BRIEN:  No, that's not necessarily correct because the cohort
consists of employees as far back as possible with 10 or more years of
exposure.  And four years ago, exposures were significantly higher than
they are today.  So as contained in our written comments, there is a
wide spread, and that's one of the values of our study, there is a very
wide spread of exposures that can be evaluated.

		MR. SCHNEIDER:  Okay.  Thank you very much.

		JUDGE SOLOMON:  Come forward.  Again, state your name and please spell
your last name.

		MS. WARD:  Dae Ward, W-a-r-d.  I'm with Alabama Power.  I just wanted
to ask you a question.  First of all, do the employees in your
population that you're looking at have predominantly daily exposures to
silica at above what level?

		MR. O'BRIEN:  That's highly variable.  They have daily exposures
absolutely.  And it ranges from sometimes non-detectable, being in a
control room for the majority of the day, to much higher than that.

		MS. WARD:  Do certain provisions of your program require exposures
above a certain level for a number of days, like 30 or 60?

		MR. O'BRIEN:  When we have a single exposure above 50 µg/m3, our
program requires a root cause analysis to be conducted to identify what
may or may not have contributed to that exposure and to determine
whether any corrective actions can be taken to bring exposures back down
below the 50.

		MS. WARD:  Okay.  And what is the employee population that you are
dealing with here in numbers?

		MR. O'BRIEN:  Our industrial sand population is roughly 800 to 900
employees.

		MS. WARD:  And you had how many cases in how long?

		MR. O'BRIEN:  I was speaking to the entire -- the NISA companies, 11
NISA companies that had been participating in the NISA SPP, not
specifically regarding Unimin.

		MS. WARD:  Okay.  And so those, how many cases?

		MR. O'BRIEN:  Eight cases.

		MS. WARD:  Eight cases?

		MR. O'BRIEN:  From 11 companies.

		MS. WARD:  And that would be what employee population?

		MR. ELLIS:  I can't give you an exact number.  I mean I think it
probably would probably reflect maybe 85 percent of the employees in the
industrial sand industry.

		MS. WARD:  Okay, because I'm trying to understand --

		MR. ELLIS:  No raw number.  I can't give you a raw number.

		MS. WARD:  Okay.  Well, it sounds like a very comprehensive program
for an identified health risk for an identified industry.  And I guess
my core question centers around would you recommend the same program,
the same regimented program for industries that don't deal with 100
percent silica, that employees don't even have exposure to silica on a
daily basis, probably less than a dozen, that are currently controlled
by other measures where the exposure may be managed by something else in
the agent, like the arsenic standard.  And would you recommend and do
the same regimented program with medical surveillance and training when
the exposure profile is completely different than 100 percent silica
product?

		MR. ELLIS:  What we have recommended to OSHA as part of our comments
in this testimony is less strict and demanding than what we require of
ourselves under our voluntary program.  We understand that OSHA has
feasibility issues.  And, frankly, that's why we feel that there is a
simplicity and a beauty and a cost-effectiveness in the NISA solution,
because you maintain the current PEL, bring people that are out of
compliance into compliance.  And the way you do that is through the
exposure monitoring and subsequent medical surveillance.

		MS. WARD:  At given triggers.

		MR. ELLIS:  At given triggers.  And if you are below what we suggest
be the action level, 50 µg, you don't even have to worry about
compliance with the law because you are already in compliance with the
law.

		JUDGE SOLOMON:  We have another witness.

		MS. WARD:  All right, thank you.

		JUDGE SOLOMON:  Okay.  So you are going to be the last witness.  There
is nobody else in line.

		DR. WEEKS:  My name is Jim Weeks.  I'm an industrial hygienist at the
--

		JUDGE SOLOMON:  Spell your last name.

		DR. WEEKS:  W-e-e-k-s.  At MSHA, the Mine Safety and Health
Administration.  I have one question.  You stated that, in the past,
people had significantly higher exposure levels then, which is common
amongst a lot of companies.  The question is did you look at the effect
of that high exposure per se and that high exposure rate per se on any
other health outcomes?

		For example, was the rate of progression amongst those people exposed
at that level, was it any higher than would be predicted by, say, simply
looking at the cumulative exposure?  Did I make that clear?  Was that a
clear question?

		MR. ELLIS:  I think what you're saying, though, is in our normal
surveillance program that we report on, we basically are identifying
cases that are greater or equal to 1/0.  But we haven't really looked at
whether somebody has progressed from 1/0 to 1/1 or 2/1.

		DR. WEEKS:  So you haven't looked at the rate of progression at all?

		MR. ELLIS:  No, no.

		DR. WEEKS:  All right, thank you.

		JUDGE SOLOMON:  Ms. Kramer, Mr. Perry, do you have questions?

		MR. PERRY:  Yes, thank you, Your Honor, we do.

		JUDGE SOLOMON:  Let me just state this is William Perry.  He has
already identified himself in the record, but I just want to make sure
--

		MR. PERRY:  Thank you, Your Honor.

		JUDGE SOLOMON:  -- everybody in the room knows who you are.

		MR. PERRY:  Yes, same person I was yesterday, I guess.  Yeah, we do
have some questions.  First, I just want to thank the NISA panel for
appearing today and for the information that you submitted to the record
so far, and congratulate you on what seems certainly to be a very
well-run and effective program.

		But just one thing you mentioned, I just wanted to double check.  You
mentioned the Dust Control Handbook.  Did you enter that into the
record?

		MR. ELLIS:  One of the many hats that I wear is also President of the
Industrial Minerals Association North America.  And, in fact, we did
introduce it into the record as part of our comments, and we will be
presenting it next week when we testify.

		MR. PERRY:  Okay, thank you so much.  We'll begin with Tiffany DeFoe.

		MS. DeFOE:  I'm not sure if this microphone is on.

		JUDGE SOLOMON:  Again, technical difficulties beyond our control.  We
have microphones at the table that work.  We know they work.  So do we
want to change?

		MS. DeFOE:  Okay, it's on now.

		JUDGE SOLOMON:  Oh, okay, go ahead.

		MS. DeFOE:  I think it's on now.  Yes, it is.  Thank you.

		JUDGE SOLOMON:  Yeah, that's it.

		MS. DeFOE:  In your description of the exposure-response study that
you are developing -- I'm sorry, let me back up a little bit.  When you
were discussing OSHA's risk assessment, you stated that a problem with
OSHA's risk assessment is that it extrapolates from high to low
concentrations of respirable silica.  And you suggested that the
exposure-response study that you are developing would help address this
issue.

		Would you please expand on the exposure database for your study and to
what extent it can provide data on health effects among workers exposed
primarily at concentrations below the current PEL?

		MR. ELLIS:  I guess the number, 50,000.

		MR. O'BRIEN:  We have tens of thousands of data points amongst the two
companies, Unimin and U.S. Silica, participating in the study.  Those
exposures range from in the early years above the PEL, sometimes
multiple times above the PEL, to where they are today, which is well
below -- typically well below the PEL.  In fact, well below 50 µg/m3.

		So we believe that because of that spread of data, based on current
technology and current analytical techniques, gravimetric and x-ray
diffraction, that the data itself is not only significant in quantity
but significant in quality.

		MS. DeFOE:  When you say that exposures are typically below 50 µg,
about how long ago would you say that became typical?

		MR. O'BRIEN:  Within Unimin, I would say that in the past, it became
typical a decade ago, at least a decade ago.

		MS. DeFOE:  Thank you.  In the study protocol, are you planning on
looking at the effects of concentration as well as cumulative exposure?

		MR. ELLIS:  I'm trying to remember.  I can't recall offhand.  We're
not epidemiologists.  But the protocol itself is part of the rulemaking
record.

		MS. DeFOE:  Thanks.  I looked at it, but I didn't see that detail in
it.

		MR. ELLIS:  Okay.

		MR. O'BRIEN:  I believe the answer is yes.

		MR. CONRAD:  The answer is yes.

		MS. DeFOE:  Thank you.  Now, you mentioned an internal target at
Unimin of 50 µg.  When was this internal target implemented?

		MR. O'BRIEN:  In the early 1990s.

		MS. DeFOE:  Okay, thank you.  And do other member companies have
internal exposure targets as well?

		MR. O'BRIEN:  I believe that they do, but I couldn't speak to the
specifics of those targets or when they were implemented.

		MS. DeFOE:  Okay.  And when the target is exceeded at Unimin, what
measures are taken at that point either with the processes or with extra
protection of the workers?

		MR. O'BRIEN:  There is a root cause analysis conducted immediately,
and that root cause analysis currently often involves a helmet cam
technology where the worker actually wears a helmet cam attached to
their hardhat for the day.  We can record where the worker is, what the
worker is doing over the course of the day, along with real-time aerosol
monitors, and tie the two together with an application developed by
NIOSH called EVADE, Enhanced Video Analysis of Dust Exposure.

		And we use that technology to see where the worker is, what they are
doing, and the real-time data tells us exactly what their exposures are
at that time.  And with that technology, in one shift, we are very
quickly able to see what's happening, why it is happening, and what we
can do to prevent the exposures from occurring in the future.

		MR. ELLIS:  And the worker can see.

		MR. O'BRIEN:  Right.

		MR. ELLIS:  So that they can modify their own behavior.

		MS. DeFOE:  That's great.  And what about respiratory protection, at
what point is respiratory protection introduced for workers?  Is it just
above the OSHA PEL or is it --

		MR. ELLIS:  At the 50.

		MS. DeFOE:  At 50.

		MR. ELLIS:  Yeah.

		MS. DeFOE:  How long has that practice been in place?

		MR. O'BRIEN:  Since the early '90s, when the internal target was
established.

		MS. DeFOE:  Okay.  Thank you very much.

		JUDGE SOLOMON:  Mr. Perry, we're actually beyond the time that had
been allocated.  How do you want to handle this?

		MS. KRAMER:  If we could just have approximately five more minutes,
Your Honor?

		MR. PERRY:  Next is Patti Downs from our Office of Technologic
Feasibility.

		MS. DOWNS:  And I promise to make this quick.  I just wanted to
confirm, I know you said you have 11 member companies participating in
the silica safety program.  How many companies do you have total?

		MR. ELLIS:  Thirty-one.

		MS. DOWNS:  Thirty-one.  And how many of those companies may have been
eligible for the program at one time but have implemented controls to
stay below the trigger?

		MR. ELLIS:  They're all eligible to participate in the program because
it's a voluntary program.  But we have 11 companies that are actively
participating.

		MS. DOWNS:  And then the rest have either implemented controls or they
don't need to, right?

		MR. ELLIS:  They chose not to participate in the program.

		MS. DOWNS:  Do you know what type of controls they have in place?

		MR. ELLIS:  Not specifically.

		MS. DOWNS:  Okay.  And then I just have some questions about the
in-house sampling that you say you do.  What kind of training did that
require to get people competent to do that sampling?

		MR. O'BRIEN:  We have a three-day program that covers our safety and
health program, everything from our medical surveillance program, our
industrial hygiene program.  It covers not only silica sampling.  It
covers noise sampling, organic solvent sampling, welding fumes sampling,
just the ins and outs of the entire program.

		MS. DOWNS:  Okay, I think that's it.  Thank you.

		MR. PERRY:  And that --

		JUDGE SOLOMON:  Okay.

		MR. PERRY:  Sorry, Your Honor.

		JUDGE SOLOMON:  Are there any other questions that you would have?

		MR. PERRY:  Yes, we have just a few more, a couple more really.
Annette Iannucci.

		MS. IANNUCCI:  Okay, good morning.  Earlier, in answering a question,
you indicated that if a worker is found to have evidence of silicosis,
you see if he or she can be moved to a lower exposure job.  How often
does this occur?

		MR. O'BRIEN:  Very rarely, as rarely both in an employee being
identified with disease and, therefore, rarely in having to move
someone.

		MS. IANNUCCI:  Okay.  But if someone is identified with disease, you
are usually able to move them to a lower exposure job?

		MR. O'BRIEN:  Typically, yes.

		MS. IANNUCCI:  What happens if you are not able to?

		MR. O'BRIEN:  Often, respiratory protection will be implemented for
that employee, but only with permission from a healthcare professional
indicating that the use of a respiratory will not negatively impact the
health of that worker or the safety of that worker.  And if, for
example, a negative demand type respirator were going to be problematic,
then a powered air-purifying respirator could be offered.

		MS. IANNUCCI:  Okay.  And then just real quick, does your medical
surveillance look for non-silicosis effects and basically what are those
tests to look for those?

		MR. O'BRIEN:  The medical surveillance program is a broad -- it is
essentially a free physical.  It includes blood chemistry, urinalysis,
the whole suite that you would typically get.  We do not -- we, Unimin,
do not specifically look for non-silicosis disease/diseases.  We really
rely on the healthcare professionals evaluating that data to indicate to
us whether or not there is an indication of some other disease process
going on.

		MS. IANNUCCI:  Okay, thank you.

		MR. STONE:  Hi, Robert Stone.  I just had a couple of questions about
your in-house exposure monitoring and the table you have on Page 24.
First of all, do you know what the size is of the smallest firm that
does in-house monitoring in your association?

		MR. O'BRIEN:  It could be a plant with only six to eight employees.

		MR. STONE:  Really?  Okay.  And you indicate some costs for analytic
-- for analyses, the analytic cost.  Why is there a range?  Doesn't it
typically go out to a lab or do you -- it's just they get discounts for
volume or something?  What would it be?

		MR. ELLIS:  Any of those.

		MR. STONE:  Okay.  And then I just want to note something.  You have
something that's curious.  You show the analytic costs alone range from
$49 to $129, with $129 would be the upper amount.  But for the total
cost, the range is $106 to $127.  And I'm guessing there might be some
odd result as to why the analytic cost alone would be more than the
total cost for a possible maximum.

		MR. O'BRIEN:  I'm looking at that data.  I'd have to go back and take
another look at that.  I understand what you're saying.

		MR. STONE:  Okay, right.  You might just -- it might be something to
clarify later.  And you have these numbers for the five firms, these
estimates for the five firms.  Are there other firms, do you know, in
the 31 -- in your 31 group that also do in-house monitoring?

		MR. ELLIS:  I would wager that most of them do, but we don't have cost
data from them.

		MR. STONE:  Okay.  That's it.

		MR. CONRAD:  Wouldn't you assume maybe that the company that
experienced the $127 maximum cost per sample would manage to have cheap
analytical and it was something else that was more?  I mean that would
be a possible explanation.

		MR. STONE:  I'm sorry, what was that explanation?

		MR. CONRAD:  In other words, the company that had the highest total
cost per sample, which was $127, may have been the company that had the
cheap analytical cost at $49.  So they don't, you know, it wouldn't
necessarily have been the highest analytical, too.

		MR. STONE:  Okay.

		JUDGE SOLOMON:  Ms. Kramer, Mr. Perry, Mr. O'Connor?

		MR. O'CONNOR:  Yes, I just have one quick question here.  In your
written submission, you state with regard to medical surveillance that
it is important for the employer as well as the employee to receive the
results of an employee's medical surveillance examination.  And I just
wanted to ask what impact, if any, you would anticipate if the results
of a medical examination were to go to the employee, but not the
employer?

		MR. O'BRIEN:  Negative.  I think it is important for the operator --
in our environment, we refer to ourselves as operators in the mining
environment.  I believe it is important for operators to also have
access to that information.

		I'm Canadian, and I grew up in the Canadian system whereby Canadian
companies have no access to the medical data.  And the first time that
you are made aware that there is a problem is when a letter shows up
from a compensation system that says you're making people sick.

		Without access to that data, you can't see disease, potentially see
disease beginning and take preventative action to prevent it from
actually having a negative health effect.

		MR. ELLIS:  That's a handicap for several of our Canadian member
companies that participate in the SPP program because they are not in a
position to report what their x-ray surveillance might show.

		MR. CONRAD:  And you also might wonder how epidemiological work could
ever get done if there was no comprehensive databases of exposure
medical surveillance data.

		MR. O'CONNOR:  Thank you.

		JUDGE SOLOMON:  Mr. Perry?

		MR. PERRY:  I just have just one question.  You talked at length about
your action level of 50 µg/m3 and the kind of actions that you take.
It sounds like then you have a pretty high degree of confidence in your
exposure monitoring results to feel that it gives you information on
which to base reasonable actions.  Is that accurate?

		MR. O'BRIEN:  That's fair.

		MR. PERRY:  Okay, thank you.  Ms. Kramer?

		MS. KRAMER:  Your Honor, I just have a couple of housekeeping matters
and also one question, if that's all right.  I just wanted to follow up
a little bit on Ms. Welch's, I believe, question earlier.  I believe
you said in your written comments that the average NISA member company's
employee's tenure with a NISA member company is 19.7 years.  Is that
right, do you recall?

		MR. ELLIS:  I can't recall.  But if we said it, I'll take your word
for it.

		MS. KRAMER:  Okay.  And they are not followed up with after they leave
--

		MR. ELLIS:  No.

		MS. KRAMER:  -- the employ of the company?

		MR. ELLIS:  No.

		MS. KRAMER:  Okay.

		MR. ELLIS:  They're no longer employees.  That's the distinction.

		MS. KRAMER:  Okay.  And just a couple of, again, housekeeping matters.
 Mr. O'Brien, the plan that you referred to during your testimony, that
was submitted as part of the record, right?  The thing you held up?

		MR. O'BRIEN:  The Silicosis Prevention Program?

		MS. KRAMER:  Yeah.

		MR. O'BRIEN:  Yes, it was.

		MS. KRAMER:  Okay.  And also two other questions about data, would you
be willing to submit the blinded data that's shown at your annual
meetings, since it is blinded and is not really, you know --

		MR. ELLIS:  That's something I'd have to consult with the members
about to see whether they prefer to do that.

		MS. KRAMER:  We'd really like that, if you could get back to us on
that.  And, finally, you mentioned that you have a program, a three-day
program, I believe, whereby you train folks to be able to do the kind of
sampling.  I was wondering if you would be able, willing to submit
either that program or a description of it to the record?

		MR. O'BRIEN:  I suspect we probably could.  I'll check with those up
my chain of command and circle back.

		MS. KRAMER:  Sure.  Thank you so much for coming.

		MR. CONRAD:  I checked our comments.  We said in 2004, a study
calculated the mean tenure for NISA member company employees fitting the
definition of the cohort for the study as being 19.7 years.

		MS. KRAMER:  Okay.

		MR. CONRAD:  That's on Page 19.

		JUDGE SOLOMON:  Okay.  Well, the time allotted for this program was
about six or seven minutes ago.  So what we are going to do is go off
the record for a second so that we can exchange panels.

		The IDPA panel is supposed to take 30 minutes.  The questions are
supposed to take about 10 minutes from the peers and the public, about
10 minutes from OSHA.  I was to take a break of five minutes.  I don't
know, we'll see when we get close to that.

		And then the Brick Industry would be starting around 11:25.  And that
means that we go to 12:30 before we would break for lunch.  The way
we're going now, there is no lunch.  So maybe there can be some
accommodation made.  So let's go off the record for a second while we
change the panel.

		(Off the record at 10:37 a.m.)

		(On the record.)

		JUDGE SOLOMON:  The IDPA program.

		MR. ELLIS:  Yes.  Good morning, again.  I am still Mark Ellis.  In
addition to my role as President of NISA, I also serve as the Executive
Director of the International Diatomite Producers Association, or IDPA.
I am joined now by Dr. Kenneth Mundt of ENVIRON International
Corporation, a consultant to IDPA, as well as Jamie Conrad, who is also
serving as IDPA's counsel for this rulemaking.

		IDPA is a nonprofit 501(c)(6) trade association representing the major
manufacturers of diatomaceous earth products worldwide.  IDPA currently
has five member companies that collectively account for the majority of
the production of diatomaceous earth products worldwide.

		As with NISA, IDPA's members' workplaces are predominantly mining
operations and, thus, are typically regulated by MSHA, not OSHA, for
purposes of occupational safety and health.  IDPA also has a substantial
stake in the outcome of the OSHA crystalline silica rulemaking, however,
for many of the same reasons that NISA does.  The most important of
these reasons is that IDPA members are committed to the safe use of
diatomaceous earth products.

		IDPA publishes a, quote, Guide to the Safe Handling of Diatomaceous
Earth Products, North America Version, which provides very general
guidance to diatomite distributors and users regarding the benefits of
engineered ventilation controls, safe work practices, and respiratory
protection programs.

		On its website, IDPA also provides a link to NISA's Occupational
Health Program for Exposure to Crystalline Silica, which you just heard
about from Mr. O'Brien.

		IDPA agrees with NISA that the exposure monitoring and medical
surveillance provisions that OSHA has proposed would provide valuable
additional workplace protections at OSHA-regulated workplaces where
diatomaceous earth products are used.

		Diatomaceous earth, also known as diatomite, is a naturally occurring,
nonmetallic mineral composed of fossilized remains of microscopic,
single-celled, aquatic algae called diatoms.  Diatomaceous earth, as it
naturally occurs, is predominantly composed of amorphous silica, that is
non-crystalline silicon dioxide.  It may also contain small amounts,
typically less than three percent, of naturally occurring crystalline
silica normally in the form of quartz.

		The natural grade of diatomite that results from crushing, drying, and
milling retains its composition.  For most applications, however, this
natural diatomite ore is then either calcined or flux-calcined in a
large rotary kiln.  Calcined grade diatomite may contain from 0 to 40
percent cristobalite, and flux-calcined grades may contain up to 75
cristobalite.

		As a result, IDPA members have longer histories of working with
cristobalite and more direct experience with it than anyone else in the
industry.  It is vitally important to them that OSHA's crystalline
silica rulemaking properly characterize the hazards presented by
cristobalite.

		As IDPA's written comments explain at greater length, IDPA strongly
believes that OSHA has been correctly guided by the evidence in
proposing to abandon the notion, now over a half century old, that
cristobalite is more hazardous than quartz.  We support OSHA's proposal
to set a single PEL, or permissible exposure limit, and a single action
level for both quartz and cristobalite.  Outside of OSHA and MSHA, no
authoritative body besides ACGIH has adopted the notion that
cristobalite is more toxic than quartz, and even ACGIH abandoned that
view 15 years ago.  Setting the same levels for quartz and cristobalite
would bring OSHA into alignment with the rest of the world.

		IDPA's principal witness today, Dr. Kenneth Mundt, has exhaustively
studied the epidemiological literature regarding the toxicity of
cristobalite.  In his testimony today, he will discuss what that review
has led him to conclude regarding the strengths of that literature and
the potential hazards of cristobalite, both absolutely and relatively to
quartz.  I now turn things over to Dr. Mundt.

		DR. MUNDT:  Thank you.  Good morning, Judge Solomon and peer
reviewers, ladies, gentlemen.  My name is Kenneth Mundt.  I am Director
of Applied Epidemiology and Health Sciences, Global Practice Area Leader
at ENVIRON International Corporation.

		I am speaking today as a consultant on behalf of the International
Diatomite Producers Association, or IDPA.  I want to thank my colleagues
Linda Dell and Lee Carlson for their assistance in conducting the review
that I will discuss.

		My purpose today is to summarize the written comments I submitted
during the comment period entitled, "Review of the Epidemiology of
Occupational Exposure to Cristobalite."  Here, I will highlight three
key points based on my review of the epidemiologic literature regarding
lung cancer risks associated with crystalline silica primarily in the
form of cristobalite, as well as silicosis risks.

		First, based on our critical review and synthesis of the published
peer review epidemiological literature on occupational exposure to
respirable crystalline silica primarily in the form of cristobalite and
human health, there is evidence of an increased risk of lung cancer,
silicosis, and nonmalignant respiratory disease among those exposed to
high levels of respirable crystalline silica dust in the form of
cristobalite.

		Second, some of the published epidemiological studies have quantified
exposure, allowing estimation of a dose-response relationship between
exposure to respirable crystalline silica in the form of cristobalite
and risk of disease, including lung cancers and silicosis.

		The literature offering the potential to quantify the health risks
specifically associated with cristobalite, however, is largely limited
to the study series led by Drs. Checkoway and Hughes from the California
diatomaceous earth cohort and several reports based on that cohort.

		Despite the availability of a number of studies attempting to evaluate
or quantify risks in relation to crystalline silica, few studies are
able to discern risks associated with cristobalite per se, largely
because most occupational settings in which cristobalite is present,
quartz is also present.

		Third, results of the quantified exposure-response analyses between
respirable crystalline silica in the form of cristobalite and lung
cancers and silicosis do not differ from comparable evaluations for
respirable crystalline silica primarily in the form of quartz.  This can
be seen for lung cancer by comparison with a pooled evaluation of lung
cancer risk in 10 cohorts exposed to crystalline silica, published by
Steenland et al. in 2001 and for silicosis by comparison with a
publication by Morfeld and others in 2013, in which the authors
illustrate a method for identifying an exposure threshold for respirable
silica exposure and silicosis morbidity risk based on a large cohort of
German porcelain workers.

		The methods we have used to identify and review the relevant
epidemiological literature are as follows:  Occupational studies
addressing the health risks of cristobalite exposure were identified by
reviewing the OSHA proposed rule for occupational exposure to respirable
crystalline silica, issued September 12, 2013, as well as conducting
searches of PubMed, based on the U.S. National Library of Medicine.
Titles and abstracts were examined to identify studies that focused on
potential cristobalite exposures.

		In considering the health risks associated with occupational
cristobalite exposures, the OSHA proposed rule reviewed primary
occupational cohorts exposed to diatomaceous earth or cristobalite
formed during processes in which various forms of silica were subjected
to high heat.  These included studies of, one, diatomaceous earth
workers in California, including Checkoway's reports of 1993, '96, '97,
'99, and Hughes, 1998; two, refractory workers in Italy, specifically,
Merlo, 1991; and, three, pottery workers in the UK, including Cherry,
1998, and McDonald, 1995.

		Five additional occupational cohort studies addressing potential
cristobalite exposure that were not discussed in the OSHA rule were
identified through PubMed searches.  Diatomaceous earth workers in
Iceland, Rafnsson, 1997; silicon carbide workers in Norway, Bugge, 2011
and 2012; refractory workers in China, Dong, 1995; and a recent update
of the UK pottery workers, Cherry, 2013.

		Information on the key features of each study was abstracted into
Excel spreadsheets, including study type, design, population, location,
comparison group, outcome, method of exposure assessment, exposure
metrics categories, measures of effect and result, 95 percent confidence
intervals, covariates adjusted, likelihood of selection bias, likelihood
of confounding, and overall quality.

		The four primary criteria used to evaluate the quality of the studies
were quantitative exposure measurement used in analysis, preferably at
the individual level; exposure dominated by cristobalite versus mixed
cristobalite and quartz exposure or predominantly quartz exposures;
control for potential confounding by smoking, especially for studies of
lung cancer; and radiographic assessment or confirmation of lung
opacities for studies on silicosis.

		Studies were accordingly classified into three tiers, with Tier 1
being the highest and Tier 3 the lowest, based on whether they met the
quality criteria.  We subsequently summarized the studies including
strengths and weaknesses by type of disease, and then synthesized the
evidence with the greatest emphasis being placed on studies of better
quality, i.e., Tier 1.

		Three studies satisfied the Tier 1 criteria in part because they
included a quantitative exposure assessment for occupational exposure
where the predominant form of respirable crystalline silica was
cristobalite.  These are Checkoway, 1997, 1999, and Hughes, 1998.
Checkoway, '97 and '98, also -- I'm sorry, '99 -- also considered
potential confounding by smoking for lung cancer.  Hughes, 1998, used
radiographic criteria for obtaining silicosis diagnosis defined as small
opacities with profusion score greater than 1/0 and/or large opacities.

		The second tier included five studies.  Rafnsson, 1997, studied an
occupational cohort predominantly exposed to cristobalite, but did not
evaluate risk using quantitative exposure estimates.  Bugge, 2011 and
'12, as well as Cherry, 98 and 2013, each used quantitative exposure
estimates and analyses, but studied cohorts either with mixed exposure
to cristobalite and other silica polymorphs or predominantly quartz.

		The third tier included five studies.  Checkoway, '93 and '96,
reported earlier evaluations of the diatomaceous earth workers cohort
exposed predominantly to cristobalite, but at that time used only
semi-quantitative exposure estimates.  Merlo, '91; Dong, '95; and
McDonald, '95, did not use quantitative exposure in analyses and studied
workers predominantly exposed to quartz but with some potential for
exposure to cristobalite.

		As can be seen in this slide, few occupational studies have been
published that evaluate disease risk in relation to quantified
categories of exposure to respirable crystalline silica primarily in the
form of cristobalite.  This is largely due to the fact that in
occupational settings in which some cristobalite may be present, there
is also considerable quartz present.

		The stronger studies examine disease risk according to categories of
quantitative estimates of cristobalite exposure, specifically among
diatomaceous earth workers.  Note, however, that the reports quantifying
cristobalite exposures were all based on the California diatomaceous
earth workers cohort.  These essentially reflect results on a single
cohort for which mortality and silicosis morbidity were updated over
time, and for which a detailed quantified exposure reconstruction was
performed, that published by Seixas in 1997.

		For lung cancer and nonmalignant respiratory disease mortality,
indirect methods of accounting for smoking were applied, and for smoking
and asbestos exposures -- and smoking and asbestos exposures were
considered as potential confounders in the lung cancer analyses.

		The majority of the studies identified and reviewed were occupational
cohort studies.  However, many reported only SMR analyses relying on an
external referent group.  While these generally are suited for detecting
excesses of lung cancer or other causes of death, they often do not or
cannot quantify exposure-response relationships.  When excess lung
cancers are detected, additional analyses within internal comparison
groups are preferred for evaluating the exposure disease relationships,
especially where confounding such as by smoking and asbestos exposure
for lung cancer is reasonably expected.

		Among the studies of higher relative quality with quantitative
exposure estimation for individual cohort members, excesses of lung
cancer mortality did not occur until cumulative exposures to respirable
crystalline silica in the form of cristobalite equaled or exceeded 5.0
mg per cubic meter years.  This is from Checkoway, 1997.  Similar
findings were presented in a subsequent report for cohort members
separated into groups with and without silicosis.  This is in Checkoway,
1999.

		In a study with quantitative exposure assessment for individual cohort
members that classified as second tier, excess lung cancer mortality was
reported in the second and third cumulative cristobalite exposure
tertiles, namely 0.028 to 0.093 mg per cubic meter years and 0.93 to 2.7
mg per cubic meter years, respectively.  This is from Bugge, 2012.

		The pattern and magnitude of these results could not be distinguished
from those for quartz exposure within this cohort.  As reported, the
Pearson correlation coefficient was .84 between cristobalite and quartz
exposure.  In other words, differences in risk, if any, between
cristobalite and quartz exposure could not be distinguished because of
the high correlation between quartz and cristobalite exposures in this
industry, the production of silicon carbide.

		In addition, excess lung cancer risk was reported in the study at
lower estimated cumulative cristobalite exposures than in the
diatomaceous earth worker study, although the magnitude of the lung
cancer risk estimates were similar for the highest exposure categories
in both, relative risks around 2.0 at exposure category 0.93 to 2.7 mg
per cubic meter years in Bugge, and around 5 or greater than 5 mg per
cubic meter years in Checkoway.

		Whether this reflects actual differences in exposure levels between
the cohorts or reflects methodological limitations of the exposure
assessment such as exposure misclassification of a shifting of the
estimated exposure distribution cannot be determined.  Ultimately, these
results likely reflect the highly correlated mixture of crystalline
silica types, as well as silicon carbide fiber and dust exposures.

		Although there was low statistical power in many of the reported
studies, disease trends were seen for increasing duration of exposure,
earlier decade or period of exposure, and high levels of cumulative
exposure.  The modest size and overall absence of a quantitative
exposure assessment in most of these studies reviewed, however, limit
the ability of these reports to determine the specific level of exposure
to cristobalite that may be associated with an increased risk of these
diseases.

		Even among the studies of higher relative quality among workers
exposed predominantly to cristobalite, concomitant exposure to quartz,
as well as incomplete control for confounding by smoking and asbestos,
remain likely.  Most Tier 2 and 3 studies included cohort members with
mixed exposures to cristobalite and quartz.

		It is illuminating to place the results reported by Checkoway and
others on the diatomaceous earth workers in the context of comparable
findings of studies of other cohorts predominantly or exclusively
exposed to crystalline silica in the form of quartz.

		Here we see the only exposure category at which lung cancer risk is
increased among the diatomaceous earth workers, i.e., the highest
exposure category is open-ended.  That one is the relative risk of 2.15
within the dotted box, which defines the size, the shape of the
continents interval around that estimate.

		Therefore, it is not possible to precisely plot the point at which
risk increases.  All previous estimates are at or about the null value.
However, no increase in lung cancer risk is evident whether considering
quartz or cristobalite below the 5 mg per cubic meter year cut point for
cumulative exposure.

		With respect to nonmalignant respiratory disease, excess mortality was
observed at cumulative exposures of greater than 2.1 and up to less than
5 mg per cubic meter years among the California diatomaceous earth
workers.

		In the only report evaluating quantitative exposure levels and
silicosis risk, that being Hughes, 1998, radiologic evidence of small
opacities with profusion scores greater than 1.1/0 and/or large
opacities were seen at cumulative exposures in the categories of greater
than 1 to up to 3 mg per cubic meter years and all higher exposure
categories.

		The results for silicosis morbidity among diatomaceous earth workers
can be compared with the results from previously mentioned German
porcelain workers.  That was Morfeld, 2013, based on Mundt, 2011, study
of the German porcelain workers.

		In proportional hazards analysis, controlling for age, sex, and
smoking, increased hazard ratios for silicosis were reported for
cumulative exposures exceeding 4 mg per cubic meter years and for
average exposures exceeding .15 mg/m3, with higher hazard ratios
reported at higher exposure categories.

		Among diatomaceous earth works with exposure intensities of .5 mg/m3
or more, relative risks were increased among those with more than 3 mg
per cubic meter years cumulative exposure.  Those with the higher
intensity, average intensity, are on the right side of this diagram.
That group had exposures exceeding .5 mg/m3, compared with those on the
left side who had not exceeded that intensity threshold.

		Consistent with these findings, toxicologic evidence also suggests
that there is no clear support for the old hypothesis that cristobalite
is more potent than quartz in producing inflammation and fibrosis.  A
recent review not addressed in the OSHA proposed rule was published by
Mossman et al. in 2013.  This review summarizes animal and in vitro
experimental data, allowing comparisons between cristobalite and quartz.
 Animal and in vitro studies have demonstrated that quartz and
cristobalite share common mechanisms of action leading to cell injury,
macrophage activation inflammation, and fibrosis.

		In conclusion, for lung cancers and silicosis, there is limited
epidemiological evidence providing quantitative exposure risk estimates
for cristobalite.  These findings do not suggest any material difference
in risk associated with crystalline silica in the form of cristobalite
versus quartz.  Furthermore, the literature indicates that in
occupational settings where cristobalite might be present, crystalline
silica in the form of quartz is often also present and may be the
dominant form to which workers are exposed.

		Taken as a whole, the toxicological and epidemiological evidence
provide no clear basis for setting a separate occupational exposure
level for crystalline silica in the form of cristobalite versus quartz.
Therefore, a synthesis of the available epidemiological literature
summarized here lends support to OSHA's proposal for a single
occupational exposure level for crystalline silica.  Thank you.

		JUDGE SOLOMON:  Okay, we are right at about -- we're about two minutes
over what the estimated time would be.  We would have -- give me some
sense of anybody from the peers that want to question?  From the public,
are there people who want to question?  Nobody.

		So now we are ahead of the time.  Mr. Conrad, do you have any
exhibits that you want to move into evidence?

		MR. CONRAD:  Your Honor, we'll include, as we did the previous panel,
the testimony of Mr. Ellis, Dr. Mundt, and the slides as a set of
three exhibits for inclusion in the record.

		JUDGE SOLOMON:  Okay.  We can make this a composite exhibit or we can
make them into individual exhibits.  What do you want to do?

		MS. KRAMER:  I'd prefer them to be separate exhibits.  If we could
mark Mr. Ellis' testimony as Exhibit 15, Dr. Mundt's as Exhibit 16,
and predictably the PowerPoint as Exhibit 17, Your Honor.

		JUDGE SOLOMON:  So 15 through 17 are admitted into evidence.

(Whereupon, the documents referred to as Hearing Exhibits 15 through 17
were marked and received in evidence.)

		MS. KRAMER:  Thank you.

		JUDGE SOLOMON:  Anything else?  Mr. Conrad?

		MR. CONRAD:  No, thank you.

		JUDGE SOLOMON:  We are going to go to the next panel, which will be --

		MS. KRAMER:  Your Honor, OSHA has some questions.

		JUDGE SOLOMON:  Oh, you do.  I'm sorry.

		MR. PERRY:  Yes, Your Honor, we do.

		JUDGE SOLOMON:  I cut you out.

		MR. PERRY:  Wouldn't want to let Dr. Mundt off scot-free now, would
we.  I believe Janet Carter has a question.

		MS. CARTER:  Thank you so much for the opportunity to ask you
questions today.  I really appreciate it.  I just have a couple of
questions.

		You cite the use of in vitro data as providing mechanistic support for
your hypothesis.  So do you support the use of in vitro mechanistic data
to supplement an understanding of underlying mechanisms of
silica-related health effects?

		DR. MUNDT:  I have to first disclaim that I am not a toxicologist and
intending to put what I find in the epidemiological literature to be
consistent with what's reported by Mossman et al. in the recent
publication.  So, if you don't mind, I would rather not venture --

		MS. CARTER:  No, no, I appreciate that.  Thank you.

		DR. MUNDT:  Venture that, yes.  Certainly, we appreciate when lines of
evidence converge and support one another, that we have greater
confidence in the interpretation of our own evidence, even the --
especially the epidemiological.

		MS. CARTER:  No, I appreciate that very much.  Thank you very much.
In your analysis of the available epidemiological data, you did a very
nice job of summarizing your criteria and tiering of the studies.  One
of your criteria was, of course, controlling for confounding of smoking.

		In the Checkoway study, you provided that as a Tier 1 study.  But in
your analysis, the Park et al. study in 2002, you excluded because it
did not -- you felt that it lacked sufficient control for confounding of
smoking.  That was -- I think that was how you phrased or similar how
you phrased it.

		I was wondering if you could expand on how you would ideally handle
smoking data.  I'm asking this because the Park data used very similar
techniques to what's fairly standard in the literature, and I was
wondering what your, as an epidemiologist, what your view of how smoking
data should be handled.

		DR. MUNDT:  Thank you.  I sense and share some frustration with the
ability to account for what is clearly great potential for confounding
from tobacco smoking.  I also, after 30 years of being an
epidemiologist, continue to be amazed at how few places such important
information is actually recorded and retained.  So quick answer in the
ideal is that that information be gathered and made available for
epidemiologic research which requires at the workplace to, in whatever
way possible, create a reasonably detailed smoking history.

		That said, what we have is what we can use.  And often it is an
indication of having ever been a smoker and, at best, the adjustment for
that is crude.  But it does give us an indication of whether confounding
is a large explanation or a relatively minor explanation.  We may not be
able to completely de-confound using that information.

		I think part of the -- there is some development in better methods for
external adjustment, meaning we don't have individual level data, but
gives us at least a sensitivity test for what range of results might
have been due to confounding under certain assumptions.

		I think at least attempting those is a good idea in most studies,
especially where we're talking about lung cancers or other respiratory
effects that are clearly caused by smoking, as well as its occupational
exposures.

		MS. CARTER:  Thank you very much.  I really appreciate that.

		JUDGE SOLOMON:  Mr. Perry?

		MR. PERRY:  Stephen Schayer, please.

		MR. SCHAYER:  Good morning, Dr. Mundt.  I just have a couple of very
general questions for you.  So, yesterday we heard testimony from
Dr. Cox that association does not inform us about causation.  So I was
wondering if you could tell us how you would go about assessing
causation.

		DR. MUNDT:  How much time do we have, Judge?  I appreciate your
question, and I think I can appreciate what Dr. Cox was referring to
is, obviously, we are bound by the limitations of observational science
in epidemiology.  But that at some point there is accumulated sufficient
evidence that we make the judgment or the inference that, yes, this is
indeed caused by this exposure.  So I think it is enhanced by, from the
previous question, knowledge from say a toxicologic mechanistic.  And
when these start to align, our confidence in that being a casual
association is enhanced.

		I think here, over time, we've had the advantage with the reduction of
exposure to see reduction in disease, which I think just makes it a home
run that the diseases are caused by, therefore can be prevented by
appropriate intervention.

		MR. SCHAYER:  Okay, thank you very much.  And the other question I
had, we also heard testimony yesterday from Dr. Long about exposure
measurement error and bias exposure-response associations.  So this
question is actually about this.  The sources that he mentioned included
between measurement variability, between sampler variability, between
laboratory variability, between sample duration variability, between
sample location variability, between sample type variability, and error
from particle potency variation.

		So I was just wondering if you considered these sources of error in
your tiering of the studies for your review or in your own study from
2011 entitled, "Respirable Crystalline Silica Exposure-Response
Evaluation of Silicosis Morbidity and Lung Cancer Mortality in the
German Porcelain Industry Cohort."

		DR. MUNDT:  Yes.  With regard to your first question, I wish I had the
luxury of enough studies to look at the independent contributions of the
various sources of variability that you mentioned.

		As applied to my own study, we engaged some of the best, at least in
Europe, industrial hygienists and chemists that understand the
measurement procedures.  And, in fact, I can't cite it off the top of my
head, but that publication itself cites some of the precursor work that
we did on understanding the variability in the exposures as measured
over time using different instruments.

		Essentially, for those who are unfamiliar with it or uninterested in
looking it up, we went to the museum, brought back the old equipment,
and ran them side-by-side in an exposure chamber to see how do we then
convert the exposure data historically to a single modern standard.  So
it was quite extensive.

		And that I hope partially answers your question or at least points you
toward where you can find a more eloquent answer to your question about
our study and what we did in it.

		MR. SCHAYER:  Okay, thank you very much.

		MR. PERRY:  Tiffany DeFoe?

		MS. DeFOE:  Good morning.  First, I'd like to ask a clarifying
question.  In your slides, when you were discussing I believe was it the
2013 paper by Dr. Morfeld -- I'm not remembering right now.  Is that
his reanalysis of your study on the pottery workers, the German pottery
workers?

		DR. MUNDT:  That's right.  It's essentially a methodologic proposal
for using computer algorithm to identify where the best fit of the data
suggests a range of threshold.  And he uses that and he applies that
method using our data on silicosis and the quantified individual
crystalline silica exposure estimates that we derived in the broader
mortality study that I published prior to that.

		MS. DeFOE:  Okay.  And you said that he concluded that there seemed to
be evidence for a threshold effect around .25 mg/m3?

		DR. MUNDT:  Yes.  I think if you look at his exact language, he cites
a range and that that was -- I think that was the point estimate.  And
he provides a range from .1 to something, .3, thank you.

		MS. DeFOE:  Okay.  Looking at your Table 2 in your 2011 publication,
it looks to me that there are 19 cases of silicosis recorded for workers
with average exposures below .2 mg/m3 and 21 cases for workers above.
Is this intention with Morfeld's conclusions?

		DR. MUNDT:  I think you have to understand the difference between
those two publications.  The 2011 was not intended to look for a
threshold.  So the categorization of individuals in cumulative exposures
was in groups.  And so part of the results were determined by the
categories we had chosen to put them in ahead of time.

		It doesn't have the ability to seek the inflection point or the point
in which the statistical analyses suggest the threshold exists and for
which the data fit the model best or the model fit the data best.  So
there is a difference in those intentions.

		If you just read our study at face value, you don't see a real
increase risk for silicosis until you get up to about 4 mg cubic
crystalline silica exposure.  So that's pretty similar to the .1, if you
just average it out over a 40-year work history.

		MS. DeFOE:  But I thought when they said they were looking for a
threshold effect, they were looking for essentially no effect.  In
silicosis, there is no effective background, correct?

		DR. MUNDT:  Well, the data suggests that there is no effected
background, as well as at low levels of cumulative exposure up to, and
you see the results in the Mundt, 2011, up to 3 or 4 mg per cubic meter
years, after which it is very clear.  Morfeld wanted to refine that from
just the basic categorical description of where risk, increased risk
occurs to a more precise point.  And in the process, he ends up
developing and presenting a methodology.  So I think half the purpose of
that paper is to demonstrate a methodology that could be used on data
like ours for purposes of determining where the point at which disease
risk is now increasing above that of the background.

		MS. DeFOE:  Do you believe there is a background risk of silicosis
among non-occupationally imposed people --

		DR. MUNDT:  Sorry to interrupt you.  I was speaking generically.  I
was speaking about the methodologic purpose of the model as it was
applied just for silicosis, well, yes, you would think that would be
clear that there would be no exposure or no silicosis among levels to
which we are exposed or workers who are mildly exposed up to some point
after which disease risk increases.  It is his methodology that is
intended to determine where that point might lie.

		MS. DeFOE:  Thank you.  And then when you -- I apologize.  I have a
couple of questions written.  Now I need to find the one I need.  On
Page 286 of your 2011 study, you state that formal threshold analyses
may be warranted, however, available numbers of silicosis cases may
limit their precision.  Would you please elaborate on what you mean
here, for example, approximately how many cases of silicosis do you
think would be needed for a threshold analysis to precisely locate a
threshold effect?

		DR. MUNDT:  It largely depends on how you define precisely.
Obviously, we advanced with the methodologies of seeking a threshold
with the modest numbers of silicosis cases that we have.  For academic
purposes, we would like there to be many more.  Obviously, we would
never want there to be more cases of silicosis.  So we have what we
have, and we made the best effort, I think, collectively and with a
range of experts from various fields, to try to maximize the
informational value of those data without over-interpreting what's
there.

		I'll be the first one to tell you there is a lot of imprecision and,
therefore, say confidence intervals or uncertainty should be respected,
and that the -- I'm hesitant to just focus on a single point number like
the .25, and prefer that you encompass the broader range that was
reported in the Morfeld, on which I was an author and consistently
brought this point to the table.

		MS. DeFOE:  Thank you.  Now, in your -- again, in your 2011 paper, you
discuss your methods and you said that you lagged exposure by 10 years
for the whole cohort and that you did analyses looking at lagged and
unlagged exposures.  And I was -- you presented these analyses for
lagged and unlagged exposures for silicosis, but I wasn't able to find
the results of the lagged analysis for lung cancer.  Was this performed
and, if so, would you describe the results?

		DR. MUNDT:  Yes.  And for the Judge and the audience, I just want to
remind you the study that we are discussing here, the last several
questions is not on cristobalite.  This is a crystalline silica
exposure.

		If you might recall from the first publication on this topic, there
was no increased risk of lung cancer at any category, so lagging becomes
moot.  It was all done, but it would have filled the paper with
predictable findings.  There was no excess and no association, so
nothing to report on lung cancer in our cohort.

		MS. DeFOE:  Thank you.  And my last question on this, would you please
characterize the age of the workers in the overall cohort?  I'm asking
because only nine percent of the studied population was deceased at the
end, and that seems to suggest a fairly young population, but it's not
clear.

		DR. MUNDT:  Again, if you don't have it in the publication in front of
you, it was in the previous one that reported the descriptive qualities
of the cohort and the SMR analyses.

		MS. DeFOE:  Thank you.

		JUDGE SOLOMON:  Mr. Perry?

		MR. PERRY:  I think Patti Downs has a question or two.

		MS. DOWNS:  And, Dr. Mundt, I'll let you off the hook for a minute.
This question is directed towards Mr. Ellis.  In your written comments,
you said that diatomite is used in thousands of products, right?  And I
was wondering does the IDPA or any of its member companies have product
stewardship programs in place and, if so, what recommendations do you
make?

		MR. ELLIS:  Well, I think that the guidelines that we published on our
website, the safe use guidelines are an example of that product
stewardship.  And then the companies, obviously, can do their own
activities.  But this is a collective activity that they pursued under
the association's umbrella.

		MS. DOWNS:  Okay, thank you.

		MR. ELLIS:  So, yeah, I'd direct you to our website.

		MS. DOWNS:  And do you collect any information from those companies?

		MR. ELLIS:  I collect information from the companies, but relative to
product stewardship, no, I mean.

		MS. DOWNS:  Do those companies, though, do they collect information
from the customers, the end users?

		MR. ELLIS:  I can't speak to that.

		JUDGE SOLOMON:  Mr. Perry?

		MR. PERRY:  Yes.  Ms. Kramer?

		MS. KRAMER:  Dr. Mundt, I'm afraid we're back to you.  I believe you
mentioned earlier that you don't have the luxury of accounting for all
the long list of variables that Stephen listed out that I don't have a
prayer of listing out myself.  Despite that, are you still reasonably
comfortable that the results that you found and analyzed accurately
reflect the actual exposure levels?

		DR. MUNDT:  I do, especially on the time periods where there were
measurements.  Again, and this is in my study with the German porcelain
workers, the oldest measures were probably the least reliable.  And
there is a time period before which there were none.

		We're often, in epidemiology, faced with the notion of, well, what
were the exposures before there were measurements.  So I would say over
the years, especially the last 20 or 30 years, where measurements were
abundant, you have a high degree of confidence in what the ambient
exposures were in various workplaces.  We, of course, have to assume
that the individuals working in those workplaces similarly were exposed.
 But we know that between worker practices or micro environments, there
would be some variability even within those homogeneous exposure groups
as characterized in the study.

		But what was, I think, encouraging is even at the qualitative level,
we knew that say the dry material handling, the formulation areas had
the highest potential for direct exposure to crystalline silicon form of
quartz, and it was really there that we saw by far the greatest risk of
silicosis.

		MS. KRAMER:  Okay.  Forgive me if this has already been asked.  We're
back to Mr. Ellis.  Do IDPA's members have any difficulty reaching the
current cristobalite PEL?  I would assume, you know, based on your
association with NISA that probably IDPA's members are meeting the
current PEL.

		MR. ELLIS:  I can speak primarily to the ones that do business in the
United States because they are governed by the Mine Safety and Health
Administration.  As you know, unlike OSHA, MSHA has a mandatory
inspection program where they visit mines twice if they are surface
operations or four times if they are underground operations.  And it is
typical that MSHA includes a health component to those inspections.
And, typically, when they come to a site that has crystalline silica
exposures, they would look for those exposures.  So MSHA actually posts
that data on its website, so I guess I would direct you there rather
than go back to my companies.

		MS. KRAMER:  As you might imagine, we are most interested in the
companies that are governed by OSHA.  Do you have any kind of response
to that?

		MR. ELLIS:  No.  I mean, again, the companies that produce the
material are essentially MSHA regulated.  It's just the fact that we
work with cristobalite that gives us the expertise that we feel can help
inform the OSHA rulemaking.

		MS. KRAMER:  One last housekeeping matter.  The information that's
posted on your website, we could, of course, print that out ourselves,
but we would appreciate it, since you probably have a cleaner copy, if
you could provide us a copy of that and submit it to the record?

		MR. ELLIS:  So the safe use guidelines, for instance?

		MS. KRAMER:  Yeah.

		MR. ELLIS:  Would you like them in Japanese?

		MS. KRAMER:  Could you translate them for us?

		MR. ELLIS:  Okay.  I could do it in English, how about that?  Okay,
thank you.

		MS. KRAMER:  That would be great.

		MR. ELLIS:  Yeah.

		JUDGE SOLOMON:  Anything else?

		MR. PERRY:  No further questions, Your Honor.  And thank you again to
the panel.

		JUDGE SOLOMON:  Okay.  Let me just -- I have to ask a question.  I
think the interest of justice requires it.  There were questions asked
about the relationship to smoking.  And in 2000, regulations were
written for the Department of Labor involving pneumoconiosis.  Silicosis
is a subset of pneumoconiosis.  And the legislative fact finding found
that there was an additive relationship between smoking and mining
generally.

		So I heard what you said.  Is there -- can you just comment on that?

		DR. MUNDT:  Yes.  I reiterate what you have heard and can be found
elsewhere.  Unfortunately, I can't contribute new insights based on our
cohort which, for various reasons, and possibly because the questioner
correctly pointed out earlier the cohort has only about 10 percent
decedents at this time, and diseases of long latency may yet to express
themselves in that cohort.  So it's a clear --

		JUDGE SOLOMON:  So you need a statistical sampling of what you have.

		DR. MUNDT:  A clear limitation or continue to follow that cohort.

		JUDGE SOLOMON:  Does anybody have any questions based on what I asked?

		DR. MUNDT:  But what I can suggest that we found and it is noted in
the publication that there was a positive correlation with silicosis and
smoking.  And I can't say epidemiologically I can understand it, but I
believe that that goes back to the question of the quality of x-rays.
Some of the x-rays in our study were from mobile units from many years
ago.  It was essentially a bus that would go from plant to plant.  And
the reading of those is clear that there is something going on in the
film, whether it was really small rounded opacities or whether it was
something else maybe reflecting.  Smoking couldn't be differentiated
there.  So I think that it did come up as a correlate of what we defined
as silicosis in our study.

		JUDGE SOLOMON:  Okay, thank you very much.  We are going to go off the
record and take a break for five minutes.  And then the people from the
Brick Industry will come forward.

		(Off the record at 11:26 a.m.)

		(On the record at 11:35 a.m.)

		JUDGE SOLOMON:  Okay, we are back on the record.  And would you state
your name for the record?

		MR. GLENN:  Yes, it's Bob Glenn, spelled G-l-e-n-n.

		JUDGE SOLOMON:  Okay.  So we have attributed about 50 minutes to the
presentation.  Is it going to take you 50 minutes?

		MR. GLENN:  Yes.

		JUDGE SOLOMON:  Okay, go ahead.

		MR. GLENN:  The primary purpose of my presentation is to discuss the
unique factors related to crystalline silica exposure in the brick
industry that I believe OSHA has not adequately considered and must
reconsider during this silica rulemaking process.

		Based on my review and the scientific evidence, it is my position that
the brick industry should not be regulated based on quantitative risk
assessment derived from exposure-response data from other industries
handling silica-containing materials, but rather derive risk estimates
based on data from the modern clay brick industry.

		To do this, I will cover three points.  First, I will cover the body
of scientific studies demonstrating no significant workplace risk for
brick workers from crystalline silica exposure exists at the current
exposure limit and that any reduction in the crystalline silica PEL is
not scientifically justified.  I strongly believe, therefore, that the
current OSHA PEL for crystalline silica is amply protective of brick
manufacturing workers and should not be reduced for the brick industry.

		Using studies from the Scottish coal workers study by Buchanan et al.,
I will show that using the prediction equations from Buchanan seriously
inflate the cases of radiological silicosis that were actually observed
in a study of brick workers in England and Scotland by the same group,
the Institute for Occupational Medicine.  Dr. Miller, here, of course,
took part in I know one of these studies, perhaps all.

		Thirdly, I'll discuss why lung cancer risks from crystalline silica
exposure is not expected, because epidemiology studies of aluminum-rich
clays are negative for lung cancer risk.  Second, the potency of quartz
containing aluminum-rich clays not only inhibits the development of
fibrosis, but also inhibits mechanisms of carcinogenesis, and that
pulmonary fibrosis is a necessary mechanistic step not only for
silicosis but for other fibrotic lung diseases that increase the risk of
lung cancer.

		I beg your indulgence if I go back.  It is an early study, but when I
started looking at the literature, I did find them quite informative in
a way, and so I'm going to cover some of these early studies.

		The first I found was a study in the United States in 1939,
unpublished, by the West Virginia State Health Department, the
Industrial Hygiene Bureau.  The study was based on inspections and
medical studies of 20 brick plants throughout the state.  According to
census figures at the time, there were just over 1,000 employees in West
Virginia were engaged in production of brick.

		The West Virginia report found the average percent quartz content from
petrographic analyses to be between 10 and 15 percent.  Using that and
putting it into the ACGIH formula of the day, the 15 percent, you would
come up with a TLV of 10 million particles per cubic foot.

		The dust concentrations shown in this table, the average of 43 samples
taken in the grinding area was 201 million particles per cubic foot,
which exceeded the ACGIH TLV for quartz about 20 times.  In the grinding
area, crusher operators exceeded the TLV by 9, pan operators in that
area by 20, screen operators by 24, and general laborers by 11.  These
are multiples of exposures above the PEL, at the time.  They averaged 31
samples from brickmaking or 49 million particles per cubic foot,
exceeded by almost 5 times, and in the brickmaking area, pug mill and
brick machine operators exceeded the TLV by 6, pressers by 8, hackers by
3, and general laborers by 3.

		This is the results of the radiological study.  A medical study was
conducted on 325 workers at 4 of the 20 plants.  The average of the
study was 36 years -- of those studies was 36 years, and the average
length of employment was 10.7 years.  I realize that is a low tenure or
a low latency, but nonetheless NIOSH considered silicosis, chronic
silicosis to occur with 10 or more years of exposure.

		Of the 319 films that were studied, 15 or 4.7 percent were read as
abnormal, being a classification of a G1 or a greater.  Seven were
interpreted with minimal changes, G1.  Two of the seven had brief
employment in the brick industry and histories of long employment in
another dusty industry.  Seven were classified as G2.  Of the seven, one
had long exposure in another dusty industry and brief exposure in brick.
 One was interpreted as N, or nodulation.  There were no cases of
complicated silicosis found.  Notice that the abnormal films were not
observed until exposures were above 10 times the allowable concentration
for the period.

		Following that study, a 1941 study in North Carolina was made and
published by Trice.  There were 28 plants involved.  He used 183
impinger measurements for particle count concentrations.  He found a
range of quartz similar to the West Virginia study and saw a 10 million
particle per cubic foot TLV would be appropriate.

		Dust concentrations was not as high as the West Virginia study.  The
average of 43 samples taking in the grinding area was 37.9 million
particles per cubic foot -- I'm going to start saying mppcf -- which
exceeded ACGIH TLV for quartz by 4.  The average of 20 samples from
brickmaking was 43.1 mppcf, which exceeded by 4.  Of 51 from the kiln,
the average exposure was only 28.3, or 2 times; however, the kiln area
cleaning of the kiln was exceptionally dusty.  Five measurements were
taken and exceeded the TLV by 14.

		Health exams including chest x-rays were performed on 1,555 brick
workers.  The chest x-rays were ready independently by two physicians
who were experienced readers from the North Carolina Dusty Trades
Program.  The Dusty Trades Program was an early prevention program that
conducted routine medical examinations of North Carolina workers in
asbestos textile mills, other asbestos exposure situations, quarry sand
plants, and clay operations.

		Both of the physicians reported no evidence of silicosis in any of the
1,555 workers.  And Trice concluded the total absence of silicosis and
other serious pulmonary pathology, which they also looked at, and the
low incidence of other respiratory diseases among the 1,555 indicate
that exposure to dust in North Carolina trades in brick does not
constitute a serious menace to health.

		This next study is a very small study from England.  Keatinge and
Potter reported, published in 1949, there were 144 workers, 100 were
examined medically, 73 underwent chest radiographs, and of those only 1
worker was reported as having changed with silicosis and that was a
Class 5, second stage silicosis.  He had previously been a bricklayer's
laborer.

		The authors referred a paper by Gardner that suggests that while dust
levels are high, the inhalation risk of free silica is not a hazard due
to the alumina in the brick clays inhibiting fibrosis.  I think this has
been the subject of much literature about aluminum being protective for
brick and especially in the clays.

		I next want to look at a comparison of some studies from the same
period in other silica using industries.  This first one is a comparison
at the West Virginia study with a refractory brick study that was made
in Pennsylvania by Fulton et al. and was published in a report as well.

		It is interesting to compare these because, of course, they are from
the same period, time period.  While many of these studies did not
relate silicosis to exposure, no exposure-response relationship, and
those that did were not comparable metrics, for instance they used
average exposure versus cumulative or by tenure only.  It is clear
evidence that the degree of silicosis morbidity in these other worksites
was striking, and it was obvious that a risk of developing silicosis
from quartz exposure and brickmaking was intrinsically different in its
potential to provoke a manifestation of silicosis.  In a comparison of
this study, of the West Virginia brick and tile, they had an overall
prevalence of five percent.  With the Pennsylvania refractory brick
workers from the same period, an overall of 50 percent prevalence of
silicosis was found.

		For the West Virginia clay brick workers exposed to cumulative, this
is cumulative exposure, 9.9 million particles per cubic foot, no cases
developed, whereas a Pennsylvania study exposed to an average, the same
average, 42 percent had silicosis.

		This next is a comparison to two studies, a North Carolina brick study
and a granite study.  This is the Trice study of North Carolina found no
cases of silicosis from 1,555, whereas the studies by Dr. Russell, some
of the early studies of silicosis in Vermont granite workers, found an
overall prevalence at 50 percent.  In the 10 to 14 year group of granite
workers, by that time 96 percent were determined to have silicosis or be
silicotic.

		The lower part of the slide, you can see a comparison.  The Keatinge
study with a study of pottery workers in West Virginia by Flynn, which
was a public health service study, the Keatinge studies, you'll
remember, had one silicotic of 73.  The prevalence rate in the pottery
was 83.  The fact that the workers had an overall silica prevalence of 8
percent in the pottery as compared to 50 percent in the granite workers
and 50 percent in the refractory brick workers might be related to the
inclusion of quartz and the aluminum-rich clays used in pottery
manufacturing.  The comparison silicosis prevalence is evidence that the
quartz in brick clays behaves differently with regards to the ability of
reduced pulmonary fibrosis and resultant silicosis in these different
industries.

		This is a study by Gillon, Rajan, and Belovsky.  It was made in Canada
in 1972.  This was the Ontario Health Department.  And a total of 77
impinger counts were taken, free silica percentage of the total airborne
dust varied from 13.2 to 24.8.  The 77 impinger samples were taken with
the mean dust counts ranging from 12 million particles per cubic foot to
1,026 million particles per cubic foot.  That is not given for specific
operations; however, plant conditions were extremely dusty across all
plants with mean impinge counts exceeding the TLV by 1.26 to 114 times.
As you can see in this table, 6 of the 10 plants exceeded the TLV by
more than a factor of 10 and no plants were below the established TLV.

		Regular chest x-rays had been taken on these workers beginning in 1959
and were conducted every 18 months.  The films were recording -- were
read according to the system developed by Drs. Riddle and Brennan, and
it is described in the paper.  Essentially, the system coded the films
from 1 to 9, with codes 5 through 9 designated as pneumoconiosis.  With
the exception of one film that showed diffuse miliary nodulation, Code
5, no chest x-ray patterns consistent with silicosis were found.

		The one case was a worker who had worked in an iron mine for 13 years
and 2 years in this tile plant.  They attributed these changes to his
former work.  He was removed from the study.

		The authors concluded that even though the workers were exposed to
dust concentrations considerably in excess of the TLV from 8 to 114
times, nevertheless radiological signs of silicosis among workers were
not present.  Moreover, they questioned whether the ACGIH TLVs at the
time of the study was applicable to the brick industry.

		This is a study by NIOSH.  Following the Trice study, 1941, almost 30
years later, North Carolina again became the focus of interest in
silicosis in the brick industry when the North Carolina Department of
Health asked NIOSH to assist in two medical studies of brick workers in
the '70s.  The health department had been conducting annual medical
surveys of brick workers for 10 years, part of this North Carolina Dusty
Trades.  They include chest x-rays and they failed to show an excess of
silicosis or other disease.  That was a note from Dr. Dubner, who at
the time was doing his residency at Duke and working with the health
department.

		Along with mobile health surveys of these workers, the department
conducted an industrial hygiene study by Carstens, who was also a
hygienist with the health department there.  Respiro average dust
concentration ranged from .88 to 2.49 mg/m3.  Despite these high levels,
no cases of silicosis were found around chest examinations for an
estimated 2,000 brick workers statewide.  And this promoted the health
department to request NIOSH to conduct the medical study.

		This is a '78 study.  It was conducted by Stringer and Anderson of
NIOSH and reported on a medical study of 558 brick workers and 592
non-dust exposed controls.  It is one of the few studies that actually
looked at controls from a non-dust population.  Spirometer chest x-rays
and respiratory disease questionnaire data provided no indication of
excess disease associated with the brick workers.  The NIOSH researchers
concluded that there was a lack of statistical evidence to support the
hypothesis of increased respiratory disease among this group of brick
workers compared to the non-dust exposed control group.

		Results of chest x-rays found few abnormal films, and there was no
significant difference in the number of abnormal between the brick
workers and the current controls.  And this table shows a number in
percentages of abnormal x-rays for males by smoking status for brick
workers in non-dust exposed.  And as you can see, the non-dust exposed
controls have comparable evidence of changes that might be silicosis,
which I think answered partly the background question during the last
session, is there a background of radiographs in a normal population
that appear to be pneumoconiosis, and the answer is yes.

		The 1990 NIOSH -- oops, this is the 1980 NIOSH study of brick workers.
 It was 395 brick workers from 5 plants, and 159 clay pipe workers also
using structural clay to produce the pipe, and 652 non-dust exposed
workers.  Interestingly, the results of the two NIOSH studies are very
similar to the Trice study.

		Again, pulmonary function data, chest x-rays, respiratory impingers,
and at this time sputum cytology gave no indications of excess
respiratory disease among the brick workers and pipe makers study group
compared to the control population.  This table is from the NIOSH report
and shows a number in percentage of abnormal workers' x-rays for both
brick and pipe workers.

		It is interesting these two NIOSH studies, the prevalence of abnormal
chest films in the brick workers are comparable to the non-dust exposed
controls, which indicates there is a background of disease in the
general population that needs to be considered when determining whether
the radiologic results of the study population are truly increased.

		This is a study from the Institute for Occupational Medicine.  The
objective of the study by Love was to assess whether exposure to heavy
clay dust containing quartz caused a significant health risk for
silicosis and to develop information regarding the size of the risk.