11/ 23/ 05 i AN EVALUATION OF THE EFFICACY OF THE LEAD HAZARD REDUCTION TREATMENTS PRESCRIBED IN MARYLAND ENVIRONMENTAL ARTICLE 6 8 FINAL REPORT SUBMITTED TO:

BALTIMORE CITY HEALTHY START, INC. BALTIMORE CITY HEALTH DEPARTMENT LEAD ABATEMENT ACTION PROGRAM BALTIMORE, MARYLAND PREPARED BY:

NATIONAL CENTER FOR HEALTHY HOUSING ( formerly the National Center for Lead Safe Housing) COLUMBIA, MARYLAND JANUARY 24, 2002 ( revised April 30, 2002)

TABLE OF CONTENTS 11/ 23/ 05 ii ABSTRACT ..................................................................................................... 1 EXECUTIVE SUMMARY ..................................................................................................... 2 I. INTRODUCTION ................................................................................................... 11 A. Background and Purpose of this Study............................................................... 11 B. Specific Research Aims and Report Objectives.................................................. 12 II. STUDY DESIGN AND SAMPLE COLLECTION PROCEDURES ............................. 14 A. Overview of the Study Design ........................................................................... 14 B. Recruitment and Enrollment Process.................................................................. 15 C. Selection Criteria for Enrolled Units .................................................................. 15 D. Data Collection Forms and Protocols ................................................................. 16 E. Dust Lead Sampling Protocols ........................................................................... 18 F. Visual Assessment Protocols.............................................................................. 20 III. LABORATORY ANALYSIS PROCEDURES ............................................................. 21 IV. QUALITY ASSURANCE AND QUALITY CONTROL .............................................. 22 A. Laboratory Quality Assurance and Quality Control............................................ 22 1. Quality Control Spiked Dust Wipe Sample Results ................................ 22 2. Quality Control Field Blank Dust Wipe Sample Results ......................... 22 3. Procedures for Dust Wipe Sample Results that Were At or Below Laboratory Report Limits ....................................................................... 22 B. Performance Audit of Field Data Collection Activities....................................... 23 C. Data Audit and Data Completeness .................................................................... 23 V. DATA PROCESSING AND STATISTICAL ANALYSIS PROCEDURES.................. 24 A. Data Entry and Processing ................................................................................. 24 B. Data Summary and Statistical Analysis .............................................................. 24 VI. ENROLLMENT RESULTS BY PHASE....................................................................... 24 VII. PRE INTERVENTION RESULTS ............................................................................... 25 A. Results of Visual Assessment of Baseline Characteristics and Conditions .......... 25 1. Baseline Physical Characteristics............................................................ 25 2. Baseline Exterior Building and Interior Unit Condition .......................... 27 B. Results of Pre Intervention Composite and Single Surface Dust Sampling ......... 30 1. Pre Intervention Composite Results........................................................ 30 2. Pre Intervention Single Surface Results.................................................. 32 3. Comparison of Pre Intervention Single Surface Results with Clearance Standards/ Guidance................................................................................ 34 11/ 23/ 05 iii VIII. IMMEDIATE POST INTERVENTION RESULTS              . 35 A. Results of Immediate Post Intervention Composite and Single Surface Dust Sampling      . ................................................................................... 35 1. Immediate Post Intervention Composite Results..................................... 35 2. Reduction in Composite Results from Pre to Immediate Post Intervention............................................................................................ 37 3. Units Having an Increase in Composite Dust Lead Loadings from Pre to Immediate Post Intervention................................................................... 39 4. Immediate Post Intervention Single Surface Results ............................... 40 5. Reduction in Single Surface Results from Pre to Immediate Post Intervention............................................................................................ 42 6. Units Having an Increase in Single Surface Dust Lead Loadings from Preto Immediate Post Intervention                .. 45 7. Comparison of Immediate Post Intervention Single Surface Results with Clearance Standards/ Guidance ............................................................... 46 B. Results of Immediate Post Intervention Visual Assessments .............................. 48 1. Types of Immediate Post Intervention " Failures" ................................... 49 2. Number of Rooms with " Failures" at Phase II ........................................ 52 3. Type of Contractor and Number of " Failures" at Immediate Post Intervention ........................................................................................... 52 C. Description of and Factors Affecting Costs ........................................................ 54 D. Description of Statistical Modeling Through Immediate Post Intervention......... 56 1. Predicting Dust Lead Loading at Immediate Post Intervention ............... 56 2. Predicting Dust Lead Loading " Failures" at Immediate Post Intervention57 3. Predicting Immediate Post Intervention Visual Assessment " Failures"... 58 IX. ONE YEAR POST INTERVENTION ( PHASE III) RESULTS.................................... 58 A. Physical Characteristics and Baseline Condition of Enrolled Units Having One Year Post intervention Data ............................................................................... 58 1. Baseline Physical Characteristics for Enrolled Units Having One Year Post Intervention Data............................................................................ 58 2. Baseline Exterior Building and Interior Unit Conditions for One Year Post Intervention Units........................................................................... 59 3. Pre Intervention Dust Lead Loadings for the 73 One Year Post Intervention Units................................................................................... 61 B. One Year Post Intervention Composite and Single Surface Dust Sampling Results ............................................................................................................... 64 1. Summary of One Year Post Intervention Composite Dust Sampling Results ................................................................................................... 64 2. Change in Composite Results from Pre to One Year Post Intervention.. 66 3. Units Having an Increase in Composite Dust Lead Loadings from Pre to One Year Post Intervention.................................................................... 68 4. Summary of One Year Post Intervention Single Surface Results ............ 69 11/ 23/ 05 iv 5. Change in Single Surface Results from Pre to One Year Post Intervention ........................................................................................... 69 6. Units Having an Increase in Single Surface Dust Lead Loadings from Preto One Year Post Intervention ................................................................ 73 7. Comparison of One Year Post Intervention Results with Clearance Standards/ Guidance................................................................................ 74 C. Results of One Year Post Intervention Visual Assessment        ... 74 1. Types of One Year Post Intervention " Failures"..................................... 75 2. Magnitude of One Year Post Intervention " Failures" ............................. 76 3. Rooms with One Year Post Intervention " Failures" ............................... 78 4. Type of Contractor and Number of One Year Post Intervention " Failures"............................................................................................... 79 D. Follow Up Data Summary for One Year Post Intervention ( Form 06) ............... 80 E. Statistical Modeling Results for One Year Post Intervention.............................. 80 1. Predicting Dust Lead Loading at One Year Post Intervention................. 80 2. Predicting One Year Post Intervention Dust Lead Loading Exceedances of Standards ............................................................................................... 81 3. Predicting One Year Post Intervention Visual Assessment " Failures" .... 82 X. SUMMARY OF TWO YEAR POST INTERVENTION RESULTS............................. 82 A. Two Year Post Intervention Dust Sampling Results........................................... 82 1. Summary of Two Year Post Intervention Composite Results ................. 82 2. Change in Composite Results from Pre to Two Years Post Intervention............................................................................................ 83 3. Change in Composite Results from One Year to Two Years Post Intervention............................................................................................ 84 B. Results of Two Year Post Intervention Visual Assessment ................................ 84 XI. SUMMARY AND DISCUSSION OF FINDINGS ........................................................ 85 A. Summary and Discussion of Findings Through Immediate Post Intervention..... 85 1. Comparison of Pre and Immediate Post Intervention Dust Lead Loading Results ................................................................................................... 85 2. Immediate Post Intervention Visual Assessment Results ........................ 87 3. Cost Data Analysis Results..................................................................... 88 B. Summary and Discussion of Findings Through Two Years Post Intervention .... 89 1. Comparison of Pre Intervention and One Year Post Intervention Dust Lead Loading Results............................................................................. 89 2. One Year Post Intervention Visual Assessment Results ......................... 90 3. Comparison of Pre Intervention and Two Year Post Intervention Dust Lead Loading Results............................................................................. 91 C. Comparing the Efficacy of the Prescribed Lead Hazard Reduction Treatments Both With and Without Window Replacement................................................... 91 XII. CONCLUSIONS AND RECOMMENDATIONS ......................................................... 92 11/ 23/ 05 v A. Conclusions ................................................................................................... 92 B. Recommendations.............................................................................................. 97 11/ 23/ 05 vi TABLES Table 1: Data Collection Form Type and Usage............................................................... 17 Table 2: Dust Wipe Sample Results Below Reporting Limits or Reported As Zero.......... 23 Table 3: Dwelling Unit Baseline Characteristics  Pre Intervention Assessment............... 27 Table 4: Units with Exterior Building Deterioration   Pre Intervention Assessment......... 28 Table 5: Number of Exterior Baseline Building Deterioration Items   Pre Intervention Assessment ................................................................................................... 28 Table 6: Units with Interior Dwelling Unit Deterioration   Pre Intervention Assessment.. 29 Table 7: Number of Interior Dwelling Unit Deterioration Items   Pre Intervention Assessment ........................................................................................................ 30 Table 8: Pre Intervention Composite Sample Dust Lead Loading .................................... 31 Table 9: Pre Intervention Single Surface Sample Dust Lead Loading............................... 33 Table 10: Immediate Post Intervention Composite Sample Dust Lead Loading ................. 36 Table 11: Percent Reduction in Pre to Immediate Post Intervention Composite Dust Lead Loadings ........................................................................................... 38 Table 12: Micrograms Per Square Foot Reduction in Pre to One Year Post Intervention Composite Dust Lead Loadings.......................................................................... 38 Table 13: Number and Percent of Units Having an Increase in Composite Dust Lead Loadings from Pre to Immediate Post Intervention........................................... 40 Table 14: Immediate Post Intervention Single Surface Dust Lead Loading Results ............ 41 Table 15: Percent Reduction in Pre to Immediate Post Intervention Single Surface Dust Lead Loadings                           43 Table 16: Micrograms Per Square Foot Reduction in Pre to Immediate Post Intervention Single Surface Dust Lead Loadings                 ... 44 Table 17: Number and Percent of Units Having an Increase in Single Surface Dust Lead Loadings from Pre to Immediate Post Intervention           . 46 Table 18: Immediate Post Intervention Single Surface " Clearance Failures"   Floors........ 47 Table 19: Immediate Post Intervention Single Surface " Clearance Failures"   Interior Window Sills ................................................................................................... 47 Table 20: Immediate Post Intervention Single Surface " Clearance Failures"   Window Troughs                            .. 48 Table 21: Number of Immediate Post Intervention Visual Assessment " Failures" Per Unit                               49 Table 22: Immediate Post Intervention Visual Assessment for Lead Hazard Reduction Treatment " Failures" ......................................................................................... 50 Table 23: Reporting Frequency of Specified Types of Treatment " Failures" at Immediate Post Intervention................................................................................................ 51 Table 24: Mean Number of Rooms per Unit with Specified Immediate Post Intervention Visual Assessment " Failures" by Treatment Group............................................ 53 Table 25: Mean Number of Immediate Post Intervention " Failures" per Unit by Type of Contractor.                           . 53 Table 26: Description of Lead Hazard Reduction Costs ..................................................... 55 Table 27: Mean Lead Hazard Reduction Costs by Contractor Type ................................... 56 Table 28: Dwelling Unit Baseline Characteristics for One Year Post Intervention Units.... 59 11/ 23/ 05 vii Table 29: Baseline Exterior Building Deterioration Summary for One Year Post Intervention Units .............................................................................................. 60 Table 30: Number of Baseline Interior Dwelling Unit Deterioration Items for One Year Post Intervention Units ...................................................................................... 60 Table 31: Summary of Baseline Interior Dwelling Unit Deterioration Items for One Year Post Intervention Units ...................................................................................... 61 Table 32: Number of Baseline Interior Dwelling Unit Deterioration Items for One Year Post Intervention Units ...................................................................................... 61 Table 33: Pre Intervention Composite Sample Dust Lead Loading for One Year Post Intervention Units .............................................................................................. 62 Table 34: Pre Intervention Single Surface Sample Dust Lead Loading for One Year Post Intervention Units .............................................................................................. 63 Table 35: One Year Post Intervention Composite Sample Dust Lead Loadings ................. 65 Table 36: Percent Reduction in Pre to One Year Post Intervention Composite Dust Lead Loadings............................................................................................................ 67 Table 37: Micrograms Per Square Foot Reduction in Pre to One Year Post Intervention Composition Dust Lead Loadings ...................................................................... 68 Table 38: Number and Percent of Units Having an Increase in Composite Dust Lead Loadings from Pre to One Year Post Intervention ............................................. 68 Table 39: One Year Post Intervention Single Surface Sample Dust Lead Loadings .......... 70 Table 40: Percent Reduction in Pre to One Year Post Intervention Single Surface Dust Lead Loadings............................................................................................................ 72 Table 41: Micrograms Per Square Foot Reduction in Pre to One Year Post Intervention Single Surface Dust Lead Loadings.................................................................... 73 Table 42: Number and Percent of Units Having an Increase in Single Surface Dust Lead Loadings from Pre to One Year Post Intervention ............................................ 73 Table 43: Percentage of LHR + W Units with One Year Post Intervention Single Surface Dust Lead Loadings Exceeding Clearance Standards ......................................... 74 Table 44: Number of One Year Post Intervention Visual Assessment " Failures" Per Unit . 75 Table 45: One Year Post Intervention Visual Assessment " Failures" ............................... 76 Table 46: Reporting Frequency of Specified Types of One Year Post Intervention Visual Assessment " Failures" ...................................................................................... 77 Table 47: Mean Number of Rooms Per Unit with Specified One Year Post Intervention Visual Assessment " Failures" by Treatment Group............................................ 79 Table 48: Mean Number of One Year Post Treatment " Failures" Per Unit by the Type of Contractor.......................................................................................................... 80 Table 49: Two Year Post Intervention Composite Sample Dust Lead Loadings................. 83 Table 50: Median Percent Reductions and Absolute Reduction in Pre to Two Year Post Intervention Composite Dust Lead Loadings...................................................... 84 Table 51: Reporting Frequency of Specified Types of Two Year Post Intervention Visual Assessment " Failures" ...................................................................................... 85 Table 52: Summary of Pre and Immediate Post Intervention Dust Lead Loading Results by Assigned Treatment Group and Sampling Method ............................................ 86 Table 53: Percentage of Units with One Year Post Intervention Single Surface Clearance " Failures" ......................................................................................................... 87 11/ 23/ 05 viii Table 54: Summary of Pre and One Year Post Intervention Dust Lead Loadings Results by Assigned Treatment Groups and Sampling Method............................................ 89 Table 55: Percentage of Units with One Year Post Intervention Single Surface Clearance " Failures" ......................................................................................................... 90 Table 56: Summary of Pre and Two Years Post Intervention Composite Dust Lead Loading Results by Assigned Treatment Group and Sampling Method .............. 91 Table 57: Median Percent Reductions in Dust Lead Loadings from Pre to One Year Post Intervention for LHR, LHR + W, and Baltimore Round One HUD Evaluation Units ................................................................................................................. 94 Table 58: One Year Post Intervention " Failure" of HUD Clearance Standards for LHR + W and Baltimore Round One HUD Evaluation Units Based on Single Surface Sampling .......................................................................................................... 95 Table 59: Median Percent Reductions in Composite Dust Lead Loadings from Pre to Two Years Post Intervention for LHR and LHR + W Units ...................................... 95 Table 60: Median Percent Reduction in Lead Loadings from Pre Intervention to Immediate Post Intervention for LHR, LHR + W, and Baltimore Round One HUD Evaluation Units ................................................................................................ 96 Table 61: Immediate Post Intervention Clearance " Failure" Rates for LHR, LHR + W, and Baltimore Round One HUD Evaluation Units ................................................... 96 11/ 23/ 05 ix FIGURES Figure 1: Type of Building   Pre Intervention Assessment ............................................... 26 Figure 2: Year Building Constructed   Pre Intervention Assessment................................. 26 Figure 3: Pre Intervention Composite Sample Dust Lead Loading Box Plot...................... 32 Figure 4: Pre Intervention Single Surface Sample Dust Lead Loading Box Plot ................ 34 Figure 5: Immediate Post Intervention Composite Sample Dust Lead Loading Box Plot ... 37 Figure 6: Pre and Immediate Post Intervention Composite Sample Dust Lead Loading for LHR and LHR+ W Units ( Logarithmic Scale) .................................................... 39 Figure 7: Immediate Post Intervention Single Surface Sample Dust Lead Results Loading Box Plot ................................................................................................... 42 Figure 8: Pre and Immediate Post Intervention Single Surface Sample Dust Lead Loading for LHR and LHR+ W Units ( Logarithmic Scale) ............................................... 45 Figure 9: Percentage of Units Having Specified Number of Rooms Per Unit with Immediate Post Intervention Visual Assessment " Failures"................................................. 52 Figure 10: Pre and One Year Post Intervention Composite Sample Dust Lead Loading Box Plot .................................................................................................................... 66 Figure 11: Pre and One Year Post Intervention Single Surface Sample Dust Lead Loading Box Plot............................................................................................................. 71 Figure 12: Percentage of Units Having Specified Number of Rooms Per Unit with One Year Post Intervention Visual Assessment " Failures"................................................. 78 APPENDICES Appendix A: Data Collection Forms Appendix B: Laboratory Analytical Procedures and QA/ QC Summary Appendix C: Physical Characteristics of Enrolled Buildings/ Dwellings   Detailed Listing Appendix D: Baseline Exterior Building and Interior Dwelling Conditions   Detailed Listing Appendix E: Composite Dust Lead Loading ( µ g/ ft2) Results   Detailed Listing Appendix F: Single Surface Dust Lead Loading ( µ g/ ft2) Results   Detailed Listing Appendix G: Complete List of Visual Assessment " Failures" by Type of Failure and Assigned Treatment Group Appendix H: Risk Reduction and Window Replacement Costs   Detailed Listing Appendix I: Statistical Data for Models Predicting Dust Lead Loading at Clearance, Dust Lead Loading " Failures" and Post Intervention Visual Assessment " Failures" Appendix J: Description of the Relationship Between Single Surface and Composite Dust Sample Results 11/ 23/ 05 1 ABSTRACT This report measured the degree to which housing is made lead safe under Maryland's lead law ( Maryland Environmental Article 6 8). Baltimore City housing units were enrolled into one of two categories. The Lead Hazard Reduction ( LHR) category included 57 units that underwent the minimum set of treatments required by the statute, and the Lead Hazard Reduction plus Windows ( LHR+ W) category included 64 units in which windows were replaced as well. Upon completion of the work and as required by the law, all units received a visual inspection, but not clearance dust testing, by Maryland accredited independent Lead Paint Visual Inspection Contractors. A second team of trained and certified lead based paint risk assessors performed a visual assessment and conducted clearance dust testing for study purposes. Any deficiencies identified by the study related visual assessment were corrected.

The study results show that dust lead loadings decreased by 70 to 99 percent between pre and immediate post intervention. However, had clearance testing been required by the statute, 46 percent, 8 percent and 27 percent of units would have " failed" clearance based on floor, window sill and window trough clearance standards of 100 µ g/ ft2, 500 µ g/ ft2 and 800 µ g/ ft2, respectively. In addition, over 90 percent of units had one or more treatment " failures" based on the studyrelated confirmatory visual assessments conducted by the second team of lead based paint risk assessors. In order to ensure that units are safe for children, this study recommends clearance dust testing and more rigorous oversight of independent Lead Paint Visual Inspection contractors who conduct visual inspections. 11/ 23/ 05 2 EXECUTIVE SUMMARY Working with the U. S. Department of Housing and Urban Development's ( HUD's) Office of Healthy Homes and Lead Hazard Control ( OHHLHC), Baltimore City's Healthy Start Program and the Baltimore City Health Department's Lead Abatement Action Program ( LAAP), the National Center for Lead Safe Housing ( the Center) designed this study to evaluate the efficacy of a prescribed set of " lead hazard reduction treatments" found in Maryland's lead law, Maryland Environmental Article 6 8 ( EA 6 8) in reducing dust lead loadings.

In this study, pre and immediate post intervention dust sampling and visual assessment tools were utilized to determine the efficacy of the law's requirement that, upon completion of the prescribed treatments, only an independent visual inspection is needed to determine whether a treated rental housing unit visually " passes" or " fails" the prescribed standard. 1 One year postintervention dust sampling and visual assessment tools were then utilized to evaluate the continued effectiveness of treatments prescribed and performed under EA 6 8. The extent to which lead hazards were decreased immediately following treatment is discussed, primarily by comparing pre with immediate post intervention dust lead loadings on floors, window sills and window troughs in a set of rooms where young children were likely to play, eat or sleep. This report also documents the extent to which lead dust re accumulated on various surfaces over a one year period after completion of the treatments, primarily by comparing one year postintervention dust lead loadings on floors, window sills and window troughs with pre intervention dust lead loadings. Limited data for a two year post intervention period are also discussed.

LAAP inspectors, who were trained and certified as lead based paint risk assessors, recruited property owners or managers to enroll their rental housing units in this study. To be enrolled, a unit had to be located in Baltimore City, constructed prior to 1950, vacant at intervention and structurally sound as determined by a LAAP screening inspection. A structurally deficient unit could be accepted into the study at a later date if the owner corrected observed deficiencies. ( Information on pre program repairs was not collected as part of the study.) Enrolled units were assigned into two treatment categories: ( 1) units that underwent EA 6 8' s prescribed treatments ( referred to as " LHR units"); and ( 2) units that underwent these treatments plus window 1 Ten " lead hazard reduction treatments" are prescribed by the standard:   Visual review of all exterior and interior painted surfaces;   Removal and repainting of chipping, peeling or flaking paint on exterior and interior painted surfaces;   Repair of any structural defect that is causing paint to chip, peel or flake that the owner of the affected property has knowledge of or, with the exercise of reasonable care, should have knowledge of;   Stripping and repainting, replacing or encapsulating all interior window sills with vinyl, metal or any other material;   Ensuring that caps of vinyl, aluminum, or any other material are installed in all window wells in order to make the window wells smooth and cleanable;   Except for a treated or replacement window that is free of lead based paint on its friction surfaces, fixing the top sash of all windows in place in order to eliminate friction caused by movement of the top sash;   Re hanging all doors necessary in order to prevent the rubbing together of a lead painted surface with another surface;   Making all bare floors smooth and cleanable;   Ensuring that all kitchen and bathroom floors are overlaid with a smooth, water resistant covering; and   HEPA vacuuming and washing the interior of the affected property with high phosphate detergent or its equivalent. 11/ 23/ 05 3 replacement ( referred to as " LHR+ W units"). The owner prepared work specifications for the lead hazard intervention, according to EA 6 8' s prescribed treatment requirements. LAAP inspectors then conducted a pre intervention walk through inspection, during which, in accordance with study protocols, they collected composite and single surface dust wipe samples from floors, window sills and window troughs in specific rooms, using HUD wipe sampling methods. During subsequent phases, in accordance with study protocols, LAAP inspectors visited units to collect composite and single surface samples from the same surfaces, rooms and locations that were sampled at pre intervention.

All samples were analyzed for total lead by laboratories participating in EPA's National Lead Laboratory Accreditation Program ( NLLAP) and proficient in the Environmental Lead Proficiency Analytical Testing Program ( ELPAT). Study protocols included laboratory and field quality assurance/ quality control procedures. Field audits and data audits were also routinely performed.

The Center was responsible for all data entry and processing. All study data were transmitted into and maintained in Jetform's FormFlow software program. Statistical analyses were performed using a SAS Institute program, which also generated reports and tables. A Crystal Reports software package was also used to generate certain reports.

A. Results Through Immediate Post Intervention A total of 177 units ( 91 LHR and 86 LHR+ W) underwent complete pre intervention baseline visual assessments. Pre intervention composite dust samples were collected in 148 of the 177 units2 and single surface dust samples were collected in 98 units. The EA 6 8 prescribed lead hazard reduction treatments were completed in 121 units ( 57 LHR and 64 LHR+ W). A full immediate post intervention study assessment was performed in these units, including a visual assessment by LAAP inspectors, collection of cost and concurrent work data and dust testing. Immediately after treatment, both the LHR and the LHR+ W units experienced substantial reductions in dust lead loadings on all surfaces ( see Table E 1 on page 4). Using either of the dust sampling methods, immediate post intervention dust lead loadings on bare floors of LHR units were generally similar to those on bare floors of LHR+ W units. However, as expected, immediate post intervention dust results for window sills and troughs in LHR units were significantly higher than those in LHR+ W units.

Despite the significant median decreases in dust lead loadings between pre and immediate postintervention data in Table E 2 ( on page 4) do show that some units experienced increases in dust lead loadings between these two phases. The percentage of LHR+ W units that underwent an increase was generally lower than that of LHR units and was comparable to that of Baltimore HUD units.

2 Twenty nine ( 29) units were not included primarily because the owners' grant applications were not approved. 11/ 23/ 05 4 Table E 1: Median Percent and µ g/ ft2 Reductions in Pre to Immediate Post Intervention Dust Lead Loadings for LHR, LHR+ W and Baltimore Round One HUD Evaluation Unitsb Surface Type and Sample Type LHR Median % Reduction (& Median µ g/ ft2 Reduction) LHR+ W Median% Reduction (& Median µ g/ ft2 Reduction) Balt. HUD Median% Reduction (& Median µ g/ ft2 Reduction) Bare Floors: Composite Single Surface 85% ( 147 µ g/ ft2) 70% ( 99 µ g/ ft2) 89% ( 225 µ g/ ft2) 88% ( 226 µ g/ ft2) NAa 95% ( 265 µ g/ ft2)

Interior window sills: Composite Single Surface 94% ( 1,686 µ g/ ft2) 84% ( 497 µ g/ ft2) 99% ( 2,596 µ g/ ft2) 99% ( 2,516 µ g/ ft2) NAa > 99% ( 2,492 µ g/ ft2)

Window Troughs: Composite Single Surface 95% ( 9,708 µ g/ ft2) 94% ( 4,111 µ g/ ft2) > 99% ( 11,284 µ g/ ft2) 99% ( 12,022 µ g/ ft2) NAa 99% ( 3,591 µ g/ ft2)

aNA= not applicable. Composite dust samples were not taken in the Baltimore Round One HUD Evaluation units. bSingle surface dust data were compared to data obtained from Baltimore City housing units enrolled in Round I of the National Evaluation of HUD's OHHLHC's Lead Hazard Control Grant Program. These units underwent interventions similar to those of the LHR+ W units, and more intensive than those of the LHR units.

Table E 2: Number and Percent of Units Having an Increase in Dust Lead Loadings from Pre to Immediate Post Intervention Surface Type and Sample Type LHR LHR+ W Baltimore HUD Units Bare Floors: Composite Single Surface 6/ 49 ( 12%) 4/ 16 ( 25%) 3/ 56 ( 5%) 4/ 63 ( 6%) NA 12/ 278 ( 4%)

Interior window sills: Composite Single Surface 4/ 52 ( 8%) 2/ 16 ( 12%) 2/ 62 ( 3%) 1/ 62 ( 2%) NA 2/ 277 ( 1%)

Window Troughs: Composite Single Surface 3/ 52 ( 6%) 2/ 16 ( 12%) 1/ 62 ( 2%) 1/ 62 ( 2%) NA 13/ 273 ( 5%)

Although EA 6 8 does not require clearance dust testing in connection with the prescribed treatments, post intervention results were compared with clearance standards to assess the extent to which the treatments produced dust results sufficient for safe occupancy of the treated units and the extent to which the prescribed independent visual inspection provided a sufficient level of risk reduction. When applying these clearance standards to immediate post intervention individual single surface dust results, an appreciable number of units had at least one floor, window sill or window trough dust lead result that exceeded the Maryland and HUD/ EPA guidance/ standards at the time of the study ( see Table E 3 on page 5). Assigned treatment group was significantly associated with post intervention window sill and trough results " passing" or 11/ 23/ 05 5 " failing" their respective standards but was not significantly associated with bare floors " passing" or " failing" standards. Had clearance testing been required, 46 percent of the units had at least one sample that would have " failed" a floor clearance level of 100 µ g/ ft2, nine percent had at least one sample that " failed" interior window sill clearance of 500 µ g/ ft2 and 27 percent had at least one sample that " failed" window trough clearance of 800 µ g/ ft2. These are higher " failure" rates than those observed for vacant Baltimore HUD units enrolled in the HUD National Evaluation ( 29 percent for floors, one percent for sills and six percent for troughs). 3 It is apparent that dust clearance testing is critical to ensure that treated dwellings are safe for reoccupancy

Table E 3: Percentage of Units with Immediate Post Intervention Single Surface Clearance " Failures" Percent of Units within Specified Category Surface Type: Floors Interior Window Sills Window Troughs Std/ Guidance:

100 µ g/ ft2

200 µ g/ ft2

500 µ g/ ft2

800 µ g/ ft2 LHR Units 60% 35% 20% 50% LHR+ W Units 41% 25% 5% 19% Total All Units 46% 28% 8% 27%

Although statistically significant dust lead loading reductions were found and each unit passed the independent visual inspection prescribed by EA 6 8, immediate post intervention confirmatory visual assessments conducted by LAAP inspectors yielded a high percentage of units ( 93 percent) with visual " failures" of one or more of the prescribed lead hazard reduction treatments ( see Table E 4 on page 6). 4 The three most common " failures" were: ( 1) not all paint intact, with some chipping, flaking and peeling paint remaining ( 75 percent of all units); ( 2) one or more painted doors continuing to rub together and/ or bind ( 43 percent); and ( 3) visible paint chips and/ or debris remaining ( 38 percent). The " failures" that LAAP inspectors recorded were easily observed, with a dwelling unit geometric mean of 1 ft2 of non intact paint reported in LHR and LHR+ W units, and dwelling unit geometric means of 8 and 16 ft2 of visible paint chips and debris in LHR and LHR+ W units. It should be noted that the areal density ( i. e., depth) and lead concentration of chips/ debris were not measured. The owner corrected treatment " failures" noted during the immediate post intervention sampling visit before tenants moved in. These corrections were " validated" by LAAP inspectors, who required owners and/ or contractors to complete their work prior to payment.

These results indicate that lead hazard reduction treatments did not completely meet the EA 6 8 risk reduction standard and more strongly suggest that the independent visual inspections failed to identify all lead hazard reduction " failures." Because only five or six independent inspectors conducted inspections for these study units, this finding does not necessarily reflect on all other Maryland certified inspectors.

3 Clearance failure rates for the Baltimore HUD units are based on initial clearance testing conducted after treatment. 4 For the purposes of this study, a treatment " failure" was defined as an observation by the LAAP inspector that one or more of the ten lead hazard reduction treatments prescribed in the statute had not been fully completed. Note that the Maryland statute did not specify a " de minimis" level above which the treatment was considered a failure; therefore, any observable deficient or missing treatment was classified as a " failure." 11/ 23/ 05 6 Table E 4: Number of Immediate Post Intervention Visual Assessment " Failures" Per Unita Number of Immediate Post Intervention Visual Assessment " Failures" Per Unitb ( 57 LHR units, 64 LHR+ W units) LHR # Units (% Units) LHR+ W # Units (% Units) All Units # Units (% Units)

" 0" lead hazard treatment " failures" 6 ( 10%) 4 ( 6%) 10 ( 8%) " 1" lead hazard treatment " failure" 7 ( 12%) 26 ( 41%) 33 ( 27%) " 2" lead hazard treatment " failures" 22 ( 39%) 21 ( 34%) 44 ( 36%) " 3" lead hazard treatment " failures" 19 ( 33%) 9 ( 14%) 28 ( 23%) " 4" lead hazard treatment " failures" 2 ( 4%) 3 ( 5%) 5 ( 4%) " 5" lead hazard treatment " failures" 1 ( 2%) 0 ( 0%) 1 ( 1%) Source: Form 05 aFor the purposes of this study, a treatment " failure" was defined as an observation by the LAAP inspector that one or more of the ten lead hazard reduction treatments prescribed in the statute had not been fully completed. " Failures" were counted on a per unit basis. Within each unit, failures were listed by room ID. bThe mean number of " failures" per unit ( 2.1 for LHR units; 1.7 for LHR+ W units) was significantly associated with assigned treatment group ( p= 0.0255).

Various cost data were collected during this study, including LAAP approved costs for the prescribed lead hazard reduction treatments, plus the additional window replacement costs for the LHR+ W units. Owner estimated turnover costs that would have been incurred even if the enrolled units had not been subject to the EA 6 8 treatments were also collected. However, these data were highly subjective and were excluded from the study. Finally, the type of contractor performing the work and information on concurrent work was also collected. The median cost for completing the prescribed treatments in LHR units and LHR+ W units was $ 2,154 and $ 1,649, respectively. Costs in LHR units were likely higher because the expense of the prescribed window treatments was included, while window replacement costs in the LHR+ W units were calculated separately. The median cost of treatment plus window replacement in the LHR+ W units was $ 4,348, with an average of 9 to 10 windows being replaced per unit. Treatment costs were higher than expected for a typical Baltimore City dwelling and should not be considered average or representative of all Baltimore City rental unit costs.

For LHR units, the mean costs for for profit contractors were slightly higher than those for property owners/ employees, while the reverse was observed for LHR+ W units. Concurrent work ( e. g., roofing, plumbing, heating and electrical repairs and replacement of other fixtures and components) was performed in 17 of the 57 LHR units and in 27 of the 64 LHR+ W units.

For each surface type, a backward elimination multiple regression model was run to identify factors that were significant predictors of immediate post intervention dust lead loadings. No significant predictors were found for bare floors. However, pre intervention sill dust lead loadings and the assigned treatment group were found to be significant predictors of immediate post intervention sill results. For window troughs, pre intervention trough dust lead loadings and the assigned treatment group were significant predictors of immediate post intervention trough results.

Clearance " failures" on bare floors was not modeled since no relationship was found when attempting to predict dust lead loading at clearance. For sills and troughs, a logistic regression model was run to identify factors that are significant predictors of whether units would have 11/ 23/ 05 7 clearance " failures" based on floor, sill and trough standards of 100 µ g/ ft2, 500 µ g/ ft2 and 800 µ g/ ft2, respectively. For sills, the only variable found to significantly predict immediate postintervention clearance " failures" was the percent of windows replaced out of the total number of windows in a unit. For troughs, the number of items of exterior building deterioration ( yielding more clearance " failures") and the percent of windows replaced ( yielding fewer clearance " failures") were found to be significant predictors of clearance " failure" at immediate postintervention

A logistic model was employed to identify factors that are significant predictors of immediate post intervention visual assessment " failures." The only variable found to significantly influence visual assessment " failure" was the number of items of exterior building deterioration ( increasing items yielding more visual assessment " failures").

B. Results Through One Year Post Intervention A total of 73 units ( 36 LHR and 37 LHR+ W) were sampled approximately one year after treatments were completed. LAAP inspectors also performed a full visual assessment at one year post intervention, noting any " failures" that had occurred since their previous visit.

At one year post intervention, composite and single surface dust lead loadings on all surfaces remained well below pre intervention levels ( see Table E 5). Substantial median percent decreases and median µ g/ ft2 decreases in dust lead loadings were observed for floors, sills and window troughs between pre and one year post intervention. Dust lead loadings on window sills and troughs in LHR units were significantly higher than those in LHR+ W units.

Table E 5: Median Percent ( µ g/ ft2) Reductions in Dust Lead Loadings for LHR, LHR+ W and Baltimore Round One HUD Evaluation Units Between Pre Intervention and One Year Post Intervention Surface Type and Sample Type LHR Median % Reduction (& Median µ g/ ft2 Reduction) Pre to 1 Year Post LHR+ W Median % Reduction (& Median µ g/ ft2 Reduction) Pre to 1 Year Post Balt. HUD Median Reduction (& Median µ g/ ft2 Reduction) Pre to 1 Year Post Bare Floors: Composite Single Surface 82% ( 87 µ g/ ft2) NAb 94% ( 335 µ g/ ft2) 96% ( 420 µ g/ ft2) NAa 84% ( 220 µ g/ ft2)

Interior window sills: Composite Single Surface 82% ( 713 µ g/ ft2) NAb 97% ( 2,803 µ g/ ft2) 97% ( 1,875 µ g/ ft2) NAa 98% ( 2,617 µ g/ ft2)

Window Troughs: Composite Single Surface 89% ( 4,507 µ g/ ft2) NAb 98% ( 12,014 µ g/ ft2) 99% ( 16,338 µ g/ ft2) NAa 90% ( 3,308 µ g/ ft2)

aNA= not applicable. Composite dust samples were not taken in Baltimore Round I HUD Eval. units. bNA= not applicable. Single surface samples were collected in only 2 LHR unit at one year post intervention. 11/ 23/ 05 8 One year post intervention single surface results for LHR+ W units were compared with clearance standards to assess the extent to which the treatments continued to produce dust results sufficient for safe occupancy of the treated units. Insufficient single surface data were available for LHR units. Less than 20 percent of units had at least one bare floor, sill, or trough result that exceeded HUD standards ( see Table E 6). The percentages for floors and troughs in LHR+ W units were significantly lower than those found for Baltimore Round I units in the HUD National Evaluation.

Table E 6: Percentage of Units with One Year Post Intervention Single Surface Clearance " Failures" Percent of Units within Specified Category Surface Type: Floors Interior Window Sills Window Troughs Std/ Guidance:

100 µ g/ ft2

200 µ g/ ft2

500 µ g/ ft2

800 µ g/ ft2 LHR+ W Units 14 11 17 14 Balt. HUD Units 57 NA 11 35 Although dust lead loadings remained less than pre intervention levels and a large percentage of units had dust lead loadings less than HUD clearance standards at one year post intervention, inspections conducted by LAAP inspectors one year after treatments were first implemented found that 96% of the 73 units had at least one visual assessment " failure" ( see Table E 7 on page 9). The most common " failures" were the same as those identified at immediate postintervention not all paint intact ( 93%), doors continuing to rub ( 41%) and visible chips or debris ( 29%). It should be noted that, for the visible paint chips or debris, the areal density ( i. e., depth) of the chips/ debris and the lead concentration in those chips/ debris was not measured. A geometric mean5 of 1 ft2 of paint was not intact, 1 ft2 of paint chips or debris remained, and 4 ft2 of flooring was not smooth and cleanable. While these types of problems were reportedly treated after immediate post intervention dust samples were collected and visual assessments were performed, these results are not entirely surprising given that few units appeared to experience turnover or had further treatments during the one year post intervention period.

For each surface type, a multiple regression model with backward elimination6 was run to identify factors that were significant predictors of one year post intervention dust lead loadings. The only significant predictor of bare floor dust lead loadings was the percent of rooms with visual assessment " failures" at one year post intervention. Pre intervention sill dust lead loadings and assigned treatment group were significant predictors of one year post intervention 5 Note that these geometric mean values were calculated using only values reported for units that had the specified type of " failure" reported. Units that did not have the specified type of " failure" reported were not included in the calculations. 6 In a multiple regression model with backward elimination, all possible predictors of the outcome are initially entered into the model. Then hypothesis tests are run to determine if any factors can be removed from the predictive equation when the other factors are retained. The least significant factor ( i. e., the factor with the largetst observed significance level) is removed and the process is repeated to determine if more factors can be dropped. In a logistic model with backward elimination, the outcome of interest is a binary response variable ( e. g., " pass/ fail"). In a Poisson regression model with backward elimination, the outcome of interest is a count variable ( e. g., number of failures). The same backward elimination procedure described above for regression modeling was followed for both the logistic and the Poisson models. 11/ 23/ 05 9 sill dust lead loadings. Assigned treatment group was the only significant predictor of one year post intervention trough dust lead loadings.

Table E 7: Number of One Year Post Intervention Visual Assessment " Failures" Per Unita Number of Visual Assessment " Failures" Per Unit ( 36 LHR units, 37 LHR+ W units) LHR # Units (% Units) LHR+ W # Units (% Units) All Units # Units (% Units)

" 0" One yr post int visual assessment " failures" 0 3 ( 8%) 3 ( 4%) " 1" One yr post int visual assessment " failure" 8 ( 22%) 13 ( 35%) 21 ( 29%) " 2" One yr post int visual assessment " failures" 12 ( 33%) 9 ( 24%) 21 ( 29%) " 3" One yr post int visual assessment " failures" 11 ( 31%) 9 ( 24%) 20 ( 27%) " 4" One yr post int visual assessment " failures" 3 ( 8%) 3 ( 8%) 6 ( 8%) " 5" One yr post int visual assessment " failures" 2 ( 6%) 0 2 ( 3%) Source: Form 05 aFor the purposes of this study, a treatment " failure" was defined as an observation by the LAAP inspector that one or more of the ten lead hazard reduction treatments prescribed in the statute had not been fully completed. " Failure" was counted on a per unit basis. Within each unit, " failures" were listed by room ID.

For floors, sills and troughs, a logistic regression model with backward elimination6 was run to identify factors that were significant predictors of whether units would have clearance " failures" at immediate post intervention based on floor, sill and trough standards of 100 µ g/ ft2, 500 µ g/ ft2 and 800 µ g/ ft2, respectively. For bare floors, the only significant predictor of one year postintervention composite results exceeding 100 µ g/ ft2 was the year of construction. For sills, preintervention sill dust lead loadings and assigned treatment group were significant predictors of one year post intervention composite dust lead loadings exceeding 500 µ g/ ft2. For troughs, the only significant predictor of one year post intervention composite dust lead loadings being above 800 µ g/ ft2 was assigned treatment group.

Finally, a Poisson regression model with backward elimination6 was employed to identify factors that are significant predictors of visual assessment " failures" at one year post intervention. Significant predictors were lead hazard reduction cost at Phase II, building type, whether work had been performed during the past year and the estimated market value of the dwelling.

C. Summary of Study Findings The main findings of this study are that dust lead loadings declined substantially immediately after EA 6 8 prescribed lead hazard reduction treatments were implemented. However, many units would not have " passed" clearance dust tests immediately following treatment had such testing been required. In addition, the prescribed independent visual inspections conducted in these units immediately following treatment generally missed many treatment " failures." At one year post intervention, dust lead loadings generally remained very low, with over 80 percent of units having floor, sill and trough dust lead loadings that were below clearance standards. However, almost every unit had at least one visual assessment failure one year after treatment. 11/ 23/ 05 10 Based on study findings, it is recommended that:   Appropriate state agencies should increase oversight of independent visual inspectors to ensure that such inspectors are performing visual inspections in accordance with approved protocols and inspector training;   Clearance dust testing should be added to the independent visual inspection as part of the lead hazard reduction treatment requirements of EA 6 8, either by regulation or by amendment to the statute;   Rental property owners and their crews and independent contractors should perform a more intensive final cleaning upon completion of the prescribed treatments;   More comprehensive window treatments may be needed to ensure that interior window sills and troughs do not continue to be an exposure source for lead; and   Proper adjustment and re hanging of doors to eliminate friction points should be an emphasis of the prescribed treatments. 11/ 23/ 05 11 I. INTRODUCTION A. Background and Purpose of this Study In May 1994, then Maryland Governor William Donald Schaefer signed comprehensive legislation into law that was designed to further two primary goals: the prevention of childhood lead poisoning resulting from deteriorating lead based paint and the preservation of the state's affordable rental housing stock. " The Lead Poisoning Prevention Program," codified variously in the Environmental Article as Section 6 801 et. seq. ( EA 6 8), in the Insurance Article as Section 734 et. seq. and in the Real Property Article as Section 8 208.2 et. seq. of the Maryland Annotated Code, was to have become effective on October 1, 1994. However, due to inevitable delays in promulgating and implementing regulations by the Maryland Department of the Environment ( MDE), the law did not become fully effective until February 24, 1996.

EA 6 8 applies to all privately owned rental housing constructed prior to 1950 ( referred to as " target housing" in the law) and, at a property owner's option, to any residential rental property constructed after 1949 but prior to 1978. The heart of the law is a system and schedule for reducing lead based paint hazards at rental unit turnover by meeting a prescribed " risk reduction standard," as found in Section 6 815. The standard can be met by performing tests to verify that surface dust lead loadings in affected property are within acceptable limits or, alternatively, by performing prescribed " lead hazard reduction treatments." These treatments include the following:

  A visual review of all exterior and interior painted surfaces;   The removal and repainting of chipping, peeling or flaking paint on exterior and interior painted surfaces;   The repair of any structural defect that is causing the paint to chip, peel or flake that the owner of the affected property has knowledge of or, with the exercise of reasonable care, should have knowledge of;   Stripping and repainting, replacing or encapsulating all interior window sills with vinyl, metal or any other material;   Ensuring that caps of vinyl, aluminum or any other material are installed in all window wells in order to make the window wells smooth and cleanable;   Except for a treated or replacement window that is free of lead based paint on its friction surfaces, fixing the top sash of all windows in place in order to eliminate the friction caused by movement of the top sash;   Re hanging all doors necessary in order to prevent the rubbing together of a lead painted surface with another surface;   Making all bare floors smooth and cleanable;   Ensuring that all kitchen and bathroom floors are overlaid with a smooth, water resistant covering; and   HEPA vacuuming and washing of the interior of the affected property with high phosphate detergent or its equivalent. 11/ 23/ 05 12 Lead hazard reduction treatments could be performed by a for profit contractor, the property owner and/ or his/ her employees, or by a non profit contractor. Regardless of their affiliation, all individuals performing risk reduction measures had to meet state and federal lead training, certification, and licensing requirements.

At each change in occupancy, an owner is required to have the housing unit inspected to verify that the lead hazard reduction treatments have been implemented. This is accomplished by having a visual inspection performed by an independent inspector certified by MDE.

In essence, under EA 6 8, children and their representatives cannot sue for traditional tort damages for lead poisoning if the rental property owner has met the risk reduction standard and certain housing unit registration requirements. Additionally, the owner and/ or his or her property insurer must make a " qualified offer" to a resident child and his or her legal representative when the child's blood lead level has exceeded 25 micrograms per deciliter ( 25 µ g/ dL) of blood. The qualified offer is, in effect, a remedial compensation settlement of the child's potential lead poisoning claim, which is designed to pay for necessary out of pocket medical treatment and relocation costs for the child's family to move to " lead safe" housing, up to a combined total of $ 17,000.

Because of this limited tort immunity and concerns over whether the prescribed lead hazard reduction treatments are protective of children's health, some critics of EA 6 8 have charged that the failure to require clearance dust testing upon completion of the treatments constitutes a major deficiency in the law. Many have questioned whether these treatments would, in fact, result in safer home environments in the absence of dust testing. For this reason, there was a need to evaluate the efficacy of both the prescribed treatments and the independent visual inspection protocol.

Although the legislature directed the Maryland Lead Poisoning Prevention Commission to study and collect information on the effectiveness of the bill's prescribed lead hazard reduction treatments, the legislature did not specifically earmark funding for such an evaluation. Therefore, the National Center for Lead Safe Housing ( Center) and the Baltimore City Healthy Start, Inc. ( Healthy Start) elected to independently evaluate the aforementioned measures through a US Department of Housing and Urban Development, Office of Healthy Homes and Lead Hazard Control ( HUD OHHLHC) funded research project. Specifically, the Center was funded under the HUD OHHLHC Lead Hazard Control Round Three Grant to the Baltimore City Health Department ( Grant No. MDLAG0045 95). ( Initial funding received from the Abell Foundation also aided in the development of this study.) Working with the HUD OHHLHC, Healthy Start and the Baltimore City Health Department's Lead Abatement Action Program ( LAAP), the Center designed this study and has analyzed all data collected.

B. Specific Research Aims and Objectives The primary goal of this study was to evaluate the efficacy of the EA 6 8 lead hazard reduction treatments, both in units that undergo these treatments alone and in units in which the treatments plus window replacement have been carried out. This report documents the extent to which lead hazards were reduced immediately following treatment, primarily by comparing the level of lead 11/ 23/ 05 13 loading in household dust collected shortly before the lead hazard reduction intervention with the level of dust collected immediately after the intervention. This report also includes a further evaluation of lead treatment efficacy using the results of dust lead sampling and visual assessments conducted 12 months post intervention. Limited data collected at approximately 24 months post intervention are also summarized.

Key questions for the study are:

1. How effective are the prescribed treatments in reducing dust lead loading on floors, interior window sills and window troughs ( i. e., window wells) to acceptable levels? 2. To what extent does lead dust re accumulate on these surfaces over a one and two year period after completion of the treatments? 3. Does the replacement of windows in units that also undergo the prescribed treatments result in substantially lower dust lead loadings immediately after completion of the treatments? 4. Do single surface dust wipe sample and composite dust wipe sample results correlate well in measuring dust lead loadings both before and after completion of the prescribed treatments? ( Note: Since this question does not specifically apply to an evaluation of EA 6 8, related findings are presented in Appendix J and are not discussed in the body of this report.) 5. Aside from lead dust sample results, do independent visual inspections accurately assess whether the prescribed treatments have been completed?

Specific objectives for this report are to:

1. Describe the physical characteristics and baseline ( i. e., pre intervention) condition of enrolled housing units, including dust lead loading on floors, interior window sills and window troughs; 2. Describe the immediate post intervention condition of the enrolled units, including their conformance with the prescribed lead hazard reduction treatments and whether they would pass an independent visual inspection, the dust lead loading and the number of windows replaced in the window replacement subset; 3. Describe the relationship between baseline building characteristics and dwelling unit conditions and the type of lead hazard reduction intervention performed ( i. e., lead hazard reduction treatments only and lead hazard reduction treatments plus window replacement); 4. Compare the efficacy of the prescribed lead hazard reduction treatments and the prescribed treatments plus window replacement in reducing dust lead loadings and bringing post intervention dust lead loadings below " clearance" standards established by MDE and by the HUD OHHLHC and the US Environmental Protection Agency ( EPA) as " guidance;" 5. Describe the dust lead loading data and post treatment/ visual inspection data for the enrolled dwelling one and two years after completion of the treatments; 6. Describe the relationship between such factors as type and age of building, baseline condition, type of contractor, amount and character of any concurrent work, turnover treatment, any notice of newly identified lead hazard or of a child with an elevated blood 11/ 23/ 05 14 lead level and the effectiveness of the treatments, including dust lead loading and continued conformance with EA 6 8 standards; and 7. Quantify any additional effectiveness of window treatment in maintaining low dust lead loadings.

Originally, there were plans to compare immediate post intervention dust wipe results with those collected at one year post intervention; however, visual assessment " failures" found at immediate post intervention were corrected upon discovery. Therefore, comparison of immediate postintervention dust wipe data with one year post intervention data is not appropriate.

II. STUDY DESIGN AND SAMPLE COLLECTION PROCEDURES A. Overview of the Study Design LAAP originally planned to enroll 200 housing units in the study, primarily three bedroom, twostory single family rowhouses of approximately 900 to 1200 square feet located in Baltimore City. One hundred ( 100) of these units were to receive the prescribed EA 6 8 lead hazard reduction treatments ( LHR) while the other 100 were to receive the prescribed lead hazard reduction treatments plus full window replacement ( LHR+ W).

The original goal of 200 study units was increased to 250 units to allow for an anticipated 20 percent attrition rate per sampling/ inspection phase. However, as a result of difficulties with attracting rental property owners to the program, suitability of certain units because of preexisting conditions ( e. g., structural defects), inability of some property owners to self finance 20 percent of the lead hazard reduction measures costs, grant approval delays and other administrative factors, that goal was reduced to 180 units and then, finally, to 150 units. In the end, 177 units underwent pre intervention inspections and 121 units completed post intervention inspections, prior to the cut off date of October 1, 1999 for completing lead hazard reduction measures in enrolled units.

LAAP did not specify how the treatments were to be carried out, with the exception of a model window replacement specification. Instead, property owners provided LAAP with treatment specifications and cost estimates; LAAP inspectors then reviewed the specifications and costs, and made adjustments with the owner's knowledge and consent. All units were vacant at the time of developing the specifications and costs, and during performance of the intervention.

LAAP inspectors collected data from enrolled units during four ( 4) sampling/ inspection phases:

  Pre Intervention ( Phase I): within four ( 4) weeks prior to the property owner and his/ her contractor performing the lead hazard control intervention;   Immediate Post Intervention ( Phase II): immediately after completion of the treatments and the visual inspection ( i. e., no more than three days), as performed by an independent inspector hired by the owner;   One year post intervention ( Phase III): 12 months post intervention ( generally within 6 weeks of the 12 month anniversary); and 11/ 23/ 05 15   Two years post intervention ( Phase IV): 24 months post intervention ( generally with 6 weeks of the 24 month anniversary).

At each phase, LAAP inspectors took composite dust samples in all enrolled housing units. Additionally, single surface samples were taken in the LHR+ W units. LAAP inspectors also performed visual assessments for dwelling unit conditions at each phase. Finally, cost and concurrent work information was collected immediately after the intervention.

B. Recruitment and Enrollment Process LAAP was responsible for the recruitment and enrollment of housing units from within the city of Baltimore. As an incentive to enroll units in the study, rental property owners would receive 80 percent of the lead hazard reduction treatment costs in the form of a grant, up to a cap of $ 10,000; the remaining 20 percent would have to be self funded. This funding was provided through LAAP's HUD OHHLHC Round III Lead Hazard Control Grant. A LAAP grant coordinator kept track of owners' contributions, which had to be received before the unit could go to settlement.

Participating rental property owners were asked to enroll two ( 2) units in the study: a LHR unit and a LHR+ W unit. A initial limit of four ( 4) enrolled units per owner was eventually lifted, although the goal remained to keep the ratio of LHR to LHR+ W units at one to one for each participating owner and for the study overall.

In order to qualify for the grant, the property owner had to substantiate that the unit was registered with MDE ( as per EA 6 8 requirements), provide evidence of fire insurance on the unit, produce documentation of acceptable lead treatment specifications and costs prior to construction, agree to rent the enrolled unit to low income families for a period of five years, maintain rents affordable to low income families for the unit, agree to dust testing and visual assessment of the unit until 24 months post intervention, and sign a grant contract. Costs were first estimated by owners or their representatives, then reviewed by LAAP and revised if spending caps were exceeded or other deficiencies were noted.

Recruitment efforts did not begin until late 1996. At that point, LAAP and Center personnel made a presentation to several representatives of the Property Owners Association of Greater Baltimore. Additionally, a " notice of funding availability" was published and LAAP asked MDE and a local childhood lead poisoning prevention advocacy organization for assistance in directing property owners to the program. In order to pilot test the data collection forms and protocols, four owners enrolled two ( 2) units each, one LHR and one LHR+ W, for a total of eight ( 8) pilot study units. These owners received full reimbursement of their treatment costs as an incentive to participate in the pilot.

C. Selection Criteria for Enrolled Units In addition to the aforementioned recruitment and enrollment criteria, a housing unit had to be located in Baltimore City, constructed prior to 1950, vacant at the time of the intervention and structurally sound, as determined by a LAAP screening inspection, to qualify for this study. 11/ 23/ 05 16 Only pre 1950 rental units were enrolled since these units were automatically subject to the law's prescribed risk reduction standard.

Conditions that could exclude a unit from the study included, but were not limited to:

  Roof and plumbing leaks;   Unsound floor or wall structures;   Non functional baths or kitchens;   Non working utilities, including plumbing, electrical and heating systems;   Pest and vermin problems;   Excessive surface problems, such as holes, cracks, excessive peeling paint or plaster deterioration;   A property with building code violations;   A unit with an existing lead violation when the prescribed lead hazard reduction treatments would not satisfy the violation notice;   More than 14 windows in the unit;   Size of the dwelling unit ( e. g., greater than 1200 square feet);   Units deemed to be a threat to the safety of LAAP inspectors;   Rents to be charged post intervention that would exceed $ 450 per month; and   Failure to register the unit with MDE, in accordance with the EA 6 8 requirements.

Eligibility of owners for grant funds and units for enrollment in the study was sometimes conditional based on the screening inspection. On occasion, LAAP was able to assist owners with structural issues by allowing up to $ 500 towards increasing structural integrity or fixing leaks ( e. g., toward a new roof). If an owner corrected one or more observed deficiencies, the unit might be accepted and the owner would then be required to prepare detailed work specifications for the intervention, closely following the prescribed lead hazard reduction treatments. After a final pre intervention walk through inspection by LAAP, the unit would be approved to proceed with construction. Information on pre program repairs was not collected as part of this research study.

D. Data Collection Forms and Protocols LAAP inspectors were trained by Center personnel to follow the data collection protocols and complete the eight ( 8) data collection forms used for this study ( see Table 1 on page 17 and Appendix A). 11/ 23/ 05 17 Table 1: Data Collection Form Type and Usage Form Name Phase I: Pre Intervention Phase II: Immediate Post Intervention Phase III: 12 Mo. Post Intervention Phase IV: 24 Mo. Post Intervention Form 01   Building and Dwelling Unit Information X Form 02   Baseline Dwelling Condition X Form 03   Sketch of Sampling Locations X Form 04A   Dust Sample Collection ( Composite) X X X X Form 04B   Dust Sample Collection ( Single Surface) X X X X Form 05   Post Treatment Assessment/ Visual Inspect. X X X Form 06   Follow Up Questions X X Form 07   De Enrollment Form * a * a * a * a aForm 07 was only completed if a unit was de enrolled from the study.

Form 01   Building and Dwelling Unit Information was designed to collect basic information about the type of building ( e. g., single detached, row house, duplex, etc.), year of construction, estimated market value ( obtained directly from the property owner), number of rooms, bedrooms, windows and approximate square feet of living space. This form was completed once: during the pre intervention phase ( i. e., Phase I).

Form 02   Baseline Dwelling Conditions was designed to collect information about obvious exterior building deterioration on roofs, gutters, downspouts, chimneys, walls and siding, windows and doors, porches and steps and the foundation, and whether the exterior ground was contaminated with paint chips. It also was used to collect information about interior dwelling unit deterioration on walls, ceilings, doors and trim, floors, heating/ cooling and plumbing systems, interior damage from roof leakage and paint condition. This form was completed once: during the pre intervention phase ( i. e., Phase I).

Form 03   Sketch of Sampling Locations was designed to record room and dust sampling locations on a sketch of each interior floor, which included room layouts. It was also used to code room numbers for the purpose of room identification on other forms. Even though this form was a reference source for room and sample locations during subsequent inspection/ sampling phases, it was completed only once: during the pre intervention phase ( i. e., Phase I).

Form 04A   Dust Sample Collection ( Composite) was designed to record a variety of data for composite dust samples, including type of surface sampled ( e. g., smooth floors, interior window 11/ 23/ 05 18 sills, window troughs), room and sample locations, dimensions of the surfaces sampled, total area sampled, sample number, total micrograms of lead per composite sample and average lead loading results measured as micrograms of lead per square foot ( µ g/ ft2). The form also recorded observations regarding unit cleanliness and occupancy status. It was completed during each of the four sampling phases in all units.

Form 04B   Dust Sample Collection ( Single Surface) was designed to record data similar to Form 04A, except that it applied solely to single surface samples. Originally intended strictly for LHR+ W units, Form 04B was also used for a number of LHR units as well. The form was completed during each of the four sampling phases.

Form 05   Post Treatment Assessment/ Visual Inspection, a two page form, was designed to collect immediate post intervention information on whether the unit was LHR or LHR+ W and, if the latter, how many windows were replaced. It also captured information on the type of contractor performing the work ( for profit, nonprofit or property owner), the cost of the LHR, the cost of window replacement ( if applicable), the estimated turnover cost of the unit had it not been subject to EA 6 8 lead hazard reduction requirements, concurrent work ( if any) performed by the owner, and dates the work started and was completed. Form 05 also contained a list of 10 questions designed to determine whether there was visual evidence that the unit had met the prescribed lead hazard reduction treatments. For any observed " failure" of a prescribed treatment, page 2 of the form was used to record the type of " failure," room and location, quantity and units of measurement, and LAAP inspector's notes on the " failure." This form was completed three times: immediate post intervention, 12 months post intervention and 24 months post intervention ( i. e., Phases II, III and IV).

Form 06   Follow Up Questions was designed to collect information from the property owner about any activities that occurred in the unit in the 12 and 24 month periods after the intervention. This information included whether any additional lead hazard reduction treatments were conducted in the unit, whether the unit had turned over and how many times, whether a tenant called to report a newly identified lead hazard, whether the owner was notified of a resident child with an elevated blood lead level, and whether a " qualified offer" was made to any resident child with a blood lead level equal to or in excess of 25 µ g/ dL.

E. Dust Lead Sampling Protocols LAAP inspectors collected all dust wipe samples for this study. These inspectors were trained and certified as both lead based paint inspectors and lead based paint risk assessors under applicable MDE regulations.

The dust sampling protocol was designed to yield information on dust lead loadings from floors ( including bare and carpeted floors), interior window sills and window troughs ( also known as window wells or exterior window sills) using both composite and single surface sampling. Samples were collected during all four sampling/ inspection phases. Originally, composite dust samples were to have been taken in all enrolled units, with single surface samples being collected only in the LHR+ W units. However, because of problems with the initial analytical laboratory selected for this study, single surface samples were also taken as a precautionary measure in 11/ 23/ 05 19 LHR units first inspected during the period from approximately November 1, 1997 until February 1, 1998, when a new laboratory was retained to replace the original laboratory.

The HUD wipe sampling method, utilizing moist towellettes placed in 50 milliter ( ml) hard shell plastic centrifuge tubes, was initially employed. Later, after the new analytical laboratory was retained, 125 ml glass jars with plastic lids were used to hold the towellettes. Plastic templates measuring 8 inches by 9 inches ( 72 square inches or one half square foot total) were secured to bare or carpeted floor sampling areas. Additionally, plastic templates measuring 2 inches by 18 inches ( 36 square inches or one quarter square foot total) were secured to interior window sills, when possible. All plastic templates were carefully cleaned between samples. Masking tape was used to define wipe sampling areas within window troughs and on interior window sills if templates were impractical. When masking tape was used to define composite sub sample areas, care was taken so that each sub sample area was within plus or minus 15 percent of other subsample areas for a given composite sample type.

Composite dust samples contained no less than two and no more than four sub samples and were collected from the following rooms, according to surface type:

Bare floor sub sample locations:

1. Entryway ( just inside the exterior doorway, slightly left of center); 2. Living room/ principal play area of children ( slightly left of center of the exterior doorway); 3. Kitchen ( slightly left of center of the interior doorway); and 4. Bedroom # 1/ smallest bedroom ( slightly left of center of the doorway).

If any of the above rooms had wall to wall carpeting, a separate composite sample was created, with sub samples being collected from these carpeted rooms. ( As discussed later, very few units had carpeted floors. Therefore, sample results for carpeted floors are not further discussed in this report.)

Window sub sample locations ( sill and troughs as separate composite samples):

1. Living room/ principal play area; 2. Kitchen; 3. Bedroom # 1/ smallest bedroom; and 4. Bedroom # 2/ next smallest bedroom.

Window sub samples were collected from the left half ( looking out) of each window unit. Only one window per room was sampled, with the selected window being sampled during subsequent sampling/ inspection phases. 11/ 23/ 05 20 Single surface samples were collected from the rooms listed below, according to surface type. All single surface samples were collected to the right of each defined area as one looks into a given room or out of a given window.

Floor sample locations ( bare or carpeted):

1. Entryway ( just inside the exterior doorway); 2. Living room/ principal play area ( just inside the exterior doorway); 3. Kitchen ( just inside the interior doorway); 4. Bedroom # 1/ smallest bedroom ( just inside the interior doorway); and 5. Bedroom # 2/ next smallest bedroom ( just inside the interior doorway).

Interior window sill sample locations:

1. Kitchen; and 2. Bedroom # 1/ smallest bedroom.

Window trough locations:

1. Living room/ principal play area; and 2. Bedroom # 2/ next smallest bedroom.

Using Forms 04A and 04B, LAAP inspectors completed laboratory submittal forms, sent the forms and samples out to the analytical laboratory and then transcribed dust lead loading results onto the forms after receiving this information from the lab.

LAAP inspectors also collected field blank samples of both the composite and single surface type after sampling the final dwelling unit of the day. Additionally, dust spiked samples prepared by the University of Cincinnati, using the National Institute of Standards and Technology ( NIST) Standard Lead Paint Dust, were inserted into the sampling stream by the inspectors at a rate of one for every 50 single surface samples and one for every 20 composite samples collected. Each composite field blank sample and spike sample was comprised of four wipes. The laboratory was blinded to all spike samples.

F. Visual Assessment Protocols In addition to collecting composite and single surface dust wipe samples, LAAP inspectors performed visual assessments during all four sampling/ inspection phases.

Pre intervention visual assessments were accomplished by observing existing building and dwelling unit conditions for signs of deterioration followed by completing the questions on Forms 01 and 02. Also, diagrams of the dwelling unit floor plan were prepared using Form 03. Immediate post intervention visual assessments required LAAP inspectors to closely inspect the building and dwelling unit for completion of the prescribed lead hazard reduction treatments. Utilizing Form 05, the inspectors would visually assess each room in the unit and certain 11/ 23/ 05 21 portions of the building exterior. Any observed treatment " failures" would be recorded on the form along with the room in which the " failure" was found and the amount of and unit of measure for the " failure" ( e. g., 10 square inches of chipping, flaking or peeling paint.

Once lead hazard reduction interventions were complete, and in anticipation of having an independent inspector perform the prescribed visual inspection, participating property owners and/ or their contractors would contact LAAP inspectors and advise them that a unit was ready for dust sampling, visual assessment and a final construction walk through. The LAAP inspectors would then collect samples and perform the visual assessment, usually immediately after the independent inspector had inspected the unit for compliance with the prescribed treatments.

Because the program paid for up to 80 percent of all pre approved intervention costs, LAAP inspectors had to perform the walk through after the dust sampling and visual assessment to determine if the original intervention specifications had been completed. If any specification was incomplete or improperly performed, the owner and/ or contractor was instructed to finish the work before LAAP would release its final payment for the intervention.

By following this sequence and protocol, LAAP inspectors sought to avoid influencing unit conditions that might improve dust sampling and visual assessment results. The overarching objective was to collect samples and to visually assess the same conditions that the independent visual inspector would have observed at the time of his/ her compliance inspection. However, in a handful of units, the LAAP inspectors did not proceed with the sampling and visual assessment when an obvious treatment had been missed ( e. g., stripping and repainting or replacing a window sill). In those cases, the inspectors would return after such missed treatments were completed, obtain dust samples and visually assess the unit.

As noted above, if the LAAP inspectors found any specification that was incomplete or improperly performed, the owner and/ or contractor was instructed to finish the work before LAAP would release its final payment for the intervention. Therefore, the one year and twoyears post intervention inspections were checks of how well treatments remained in place 12 and 24 months, respectively, following the completion of all immediate post intervention work.

III. LABORATORY ANALYSIS PROCEDURES As a prerequisite, the analytical laboratory selected to analyze dust samples for this study had to be recognized by EPA as participating in the National Lead Laboratory Accreditation Program ( NLLAP). The lab had to show evidence of being proficient in lead analysis under the Environmental Lead Proficiency Analytical Testing Program ( ELPAT). All dust samples had to be analyzed for total lead as required in the HUD Guidelines for the Evaluation and Control of Lead Based Paint Hazards in Housing. Because of problems detected in the analysis of the composite samples by the first laboratory ( designated " Lab A"), a second laboratory (" Lab B") was hired to replace Lab A as the study laboratory ( see Appendix B for details). Analytical procedures for each laboratory are provided in Appendix B. Lab B was used for the analysis of all one year and two years post intervention data. 11/ 23/ 05 22 IV. QUALITY ASSURANCE AND QUALITY CONTROL A. Laboratory Quality Assurance and Quality Control 1. Quality Control Spiked Dust Wipe Sample Results As noted above, LAAP inspectors periodically submitted single surface and composite spiked dust wipe samples ( using the NIST standard) to the study laboratory. Early in the project, LAAP and the Center noted deficiencies in composite spike recoveries and other observations that led LAAP to replace Lab A with Lab B. Samples potentially associated with Lab A's unacceptable composite spike results were excluded from all analyses presented in this report. No other samples were excluded on the basis of QC spike sample results. Spike sample submittal procedures, as well as details concerning the spike results, are provided in Appendix B.

2. Quality Control Field Blank Dust Wipe Sample Results As noted in Section III. E, composite and single surface field blank dust wipe samples were prepared by LAAP inspectors and submitted to the laboratory after sampling the final dwelling unit of the day.

The presence of detectable lead in a field blank sample could suggest several potential problems: sample collection may have been poorly conducted ( e. g., lead may in fact have been introduced into a sample container from an inspector's glove, a contaminated sample container, or from other sources not under experimental control); contamination and poor sample handling may have occurred at the laboratory; or there may have been errors in laboratory measurement procedures. For both Lab A and Lab B, composite and single surface field blank results were considered acceptable. Therefore, no composite or single surface samples were excluded from this report based on field blank results. Details concerning field blank results are provided in Appendix B.

3. Procedures for Dust Wipe Sample Results that Were At or Below Laboratory Report Limits A high percentage of both composite and single surface dust wipe sample results were below the reporting limits of both Lab A and Lab B. Lab A's reporting limits varied from 5 µ g/ sample to 24 µ g/ sample, Lab B's single surface sample reporting limit was 10 µ g/ sample, and Lab B's composite sample reporting limit was 20 µ g/ sample.

Because one of the most important measures of intervention outcome   the change in dust lead loadings over time   could be at or below the laboratory's reporting limits, Lab B supplied the actual machine values for composite and single surface samples with lead content below reporting limits. For the few cases in which Lab B reported a machine value of zero ( i. e., the sample's lead content could not be distinguished from the machine's " background noise"), the zero values were replaced with the laboratory's reporting limit divided by the square root of two. Lab A did not supply actual machine values; sample results reported by this laboratory to be at or below reporting limits were also replaced with a value calculated by taking Lab A's reporting 11/ 23/ 05 23 limit and dividing it by the square root of two. Based on data shown in Table 2, a total of 133 results underwent this conversion.

Table 2: Dust Wipe Sample Results Below Reporting Limits or Reported As Zeroa Surface Typeb Pre Intervention Samples # Samples/ Total (% Samples) Immediate Post Intervention Samples # Samples/ Total (% Samples) One Year Post Intervention Samples # Samples/ Total (% Samples) Two years postintervention Samples # Samples/ Total (% Samples) Bare Floor: Composite Single Surface 0/ 148 ( 0.0%) 1/ 467 ( 0.2%) 3/ 108 ( 3%) 49/ 373 ( 13%) 3/ 68 ( 4%) 11/ 168 ( 6%) 1/ 24 ( 4%) 3/ 64 ( 5%)

Window Sill: Composite Single Surface 1/ 152 ( 0.7%) 1/ 196 ( 0.5%) 4/ 116 ( 3%) 28/ 164 ( 17%) 0/ 73 ( 0%) 8/ 76 ( 10%) 0/ 24 ( 0%) 0/ 26 ( 0%)

Window Trough: Composite Single Surface 1/ 152 ( 0.7%) 0/ 191 ( 0.0%) 4/ 116 ( 3%) 13/ 157 ( 8%) 0/ 72 ( 0%) 1/ 75 ( 1%) 0/ 24 ( 0%) 0/ 26 ( 0%)

Total All Surface Types and Sample Types 4/ 1306 ( 0.3%) 101/ 1034 ( 10%) 23/ 532 ( 4%) 4/ 188 ( 2%) aLab A recorded results below reporting limits and Lab B recorded results as zero. bBecause very few units had carpeted floors, sample results for carpeted floors were excluded from this study.

B. Performance Audit of Field Data Collection Activities On six different occasions, Center staff observed LAAP inspectors in the field collecting single surface and composite dust wipe samples, performing visual assessments and completing the data collection forms. LAAP inspectors were critiqued for their adherence to the data collection protocols and their dust wipe sampling technique. Although the LAAP inspectors generally performed to expectations, the Center's representatives provided on site guidance and written recommendations to improve sampling and data collection.

During several visits to the LAAP office, Center staff reviewed unit files and other project documentation for completeness and adherence to the study protocols. Center representatives also made on site and written recommendations for improvements during these visits, particularly regarding tracking of follow up inspection assignments.

C. Data Audit and Data Completeness The Center was responsible for auditing all data submitted by LAAP for correctness, completeness and adherence to the data collection protocols. After completion by LAAP inspectors, data collection forms ( and laboratory analysis reports) were submitted to the Center for initial review and, if appropriate, data entry and processing. Center staff reviewed each form for missing and/ or unclear answers and data, use of proper answer codes and values, insertion of correct laboratory results and calculation of dust lead loading, and consistency of room number assignments and sampling locations across the different sampling/ inspection phases. When 11/ 23/ 05 24 errors and/ or missing information were detected, the Center would return forms to LAAP, with detailed instructions for correction or clarification unless questions could be resolved easily by telephone. LAAP would then make revisions and return the corrected forms to the Center, which then performed a final audit before preparing the forms for data entry.

V. DATA PROCESSING AND STATISTICAL ANALYSIS PROCEDURES A. Data Entry and Processing The Center was responsible for all data entry and data processing. An electronic facsimile, as well as the actual hard copy version, of each data collection form was created in Jetform's FormFlow software program. After receiving the completed field forms from LAAP, the Center's Data Coordinator would enter data from the field forms directly into the electronic version of the forms in FormFlow. A hard copy of the completed form was then printed out and reviewed for errors and/ or missing information by the Data Coordinator and other Center staff. After corrections were made and entered into the electronic version of the form, a revised hard copy of the form, along with the LAAP field form, was placed in a file folder created for each enrolled unit and stored at the Center.

B. Data Summary and Statistical Analyses As noted, all study data were transmitted into and maintained in FormFlow. Statistical analyses of these data were performed using a SAS Institute program ( Versions 6.12 and 8.0), which also generated reports and tables. Finally, aside from SAS reports, the Crystal Reports software package was used to generate other reports by directly downloading dBase data from FormFlow.

VI. ENROLLMENT RESULTS BY PHASE A total of 177 units underwent pre intervention inspections and 121 units completed immediate post intervention inspections prior to the cut off date of October 1, 1999 for completing lead hazard reduction measures in enrolled units. These 121 units were followed for the 12 and 24 month post intervention inspections, with a total of 73 having complete one year postintervention data collected and a total of 24 having complete two years post intervention data. The decrease in units between immediate and one year post intervention was primarily due to the fact that tenants did not move into units until after Phase II, meaning that tenants were likely unaware of the study until LAAP inspectors visited the occupied unit at one year postintervention Tenants' lack of familiarity with the project often meant that they were reluctant to allow access for one year and two years post intervention sampling. Other problems included the growing number of conflicting duties for the LAAP inspectors over the lengthy period of this study and a temporary halt in the data collection while immediate post intervention results underwent review.

Because so few units had complete two years post intervention data, the major part of this report necessarily focuses on the results of the first three phases to meet the study objectives. A brief description of the two years post intervention results for the 24 units that had 24 month postintervention inspections is presented in Section X. 11/ 23/ 05 25 VII. PRE INTERVENTION RESULTS A. Results of Visual Assessments of Baseline Characteristics and Conditions A total of 177 units ( 91 LHR and 86 LHR+ W) underwent complete pre intervention visual assessments using Forms 01, 02 and 03. However, pre intervention dust testing was often delayed until the property owner's project specifications and grant application had been approved and a final pre construction " walk through" was completed. Because some applications were not approved, this delay resulted in pre intervention composite dust samples being obtained from 148 of the 177 units ( 74 LHR and 74 LHR+ W) and single surface dust samples from 98 units ( 25 LHR and 73 LHR+ W). The number of LHR units having single surface samples collected was much less than that of the LHR+ W units because, as discussed in Section II. E, single surface samples were originally to be collected only from LHR+ W units. Single surface samples were collected from LHR units for only a short period of time when laboratory analysis of composite samples was being investigated by the Center and LAAP ( see Appendix B).

In order to more fully characterize initial building and dwelling unit conditions, this section summarizes physical characteristics and baseline condition data for the 177 units for which such data were collected. Appendix C contains a detailed presentation of physical characteristics for each enrolled unit. Appendix D presents a complete list of baseline exterior conditions for each building and of baseline interior conditions for each unit. Complete pre intervention dust lead loading results for composite and single surface samples are provided in Appendices E and F, respectively.

1. Baseline Physical Characteristics A Chi square test was used to determine if there was a relationship between pre intervention housing characteristics and conditions ( i. e., variables) and assigned treatment groups ( i. e., LHR versus LHR+ W units). Such associations may indicate differences in the baseline characteristics and conditions of LHR versus LHR+ W units; these differences had to be taken into account before the effectiveness of the lead hazard reduction treatments could be fully evaluated. Variables having a significant association with treatment group are summarized below.

Building Type. The majority ( 71 percent) of the residential buildings initially enrolled in the study were single family rowhouses, which are common in Baltimore City. Building type was not significantly associated with the assigned treatment group. Other enrolled building types and their relative percentages as part of total enrollment are displayed in Figure 1. 11/ 23/ 05 26 Figure 1: Type of Building   Pre Intervention Assessment Source: Form 01 Note: Based on Chi square testing, building type not significantly associated with assigned treatment group.

Building Construction Period. Many of the residential buildings in Baltimore City, including 84 percent of those initially enrolled in the study, were constructed 70 or more years ago. The largest percentage of enrolled buildings ( 45 percent) was those built between 1920 and 1929. Construction period was not significantly associated with the assigned treatment group. The age/ period of construction for all enrolled buildings is displayed in Figure 2.

Figure 2: Year Building Constructed   Pre Intervention Assessment Note: Based on Chi square testing, construction period not significantly associated with assigned treatment group. 70 8 10 3 3 3 2 72 8 6 5 6 2 1 71 8 8 4 5 3 2 0 10 20 30 40 50 60 70 80 Rowhouse More than 4 units in bld. Triplex Duplex Four plex Two flats Single detached Percentage of Units LHR Units LHR+ W Units All Units LHR Units 16%

22%

43% 11% 8%

Pre 1910 1910 1919 1920 1929 1930 1939 1940 1949 LHR+ W Units 15%

23%

48% 7% 7%

Pre 1910 1910 1919 1920 1929 1930 1939 1940 1949 11/ 23/ 05 27 Other Dwelling Unit Baseline Conditions. In order to identify important characteristics about initially enrolled dwelling units, LAAP inspectors collected information about estimated real estate market value, total number of rooms and bedrooms, number of windows, including unpainted ones ( e. g., vinyl and aluminum replacement windows), and the size of the interior living space. A t test was used to test for significant differences in the mean values for LHR and LHR+ W units. Generally, the LHR and LHR+ W units possessed similar characteristics, the mean values for which are displayed in Table 3. However, the total number of windows in a dwelling unit was marginally associated with the assigned treatment group ( p value = 0.0641), with LHR+ W units having slightly more windows. The number of unpainted windows was also significantly associated with the treatment group assignment ( p value= 0.0088), the mean being higher for LHR units.

Table 3: Dwelling Unit Characteristics   Pre Intervention Assessment Dwelling Unit Characteristic ( 91 LHR units, 86 LHR+ W units) Mean ( std. deviat.) for LHR Units Mean ( std. deviat.) for LHR+ W Units Estimated market value of dwelling unita ( mean rounded to nearest $ 100) $ 22,500 ($ 10,900) $ 23,000 ($ 12,000)

# of rooms in dwelling unita 6 ( 2) 7 ( 2)

# of bedrooms in dwelling unita 3 ( 1) 3 ( 1)

# of windows in dwelling unitb 9 ( 3) 10 ( 4)

# of unpainted windows in dwelling unitc ( vinyl, aluminum) 1.5 ( 3) 0.5 ( 2)

Approximate square feet of living spacea 1,100 ft2 ( 340) 1,100 ft2 ( 380)

Source: Form 01 aThese building condition items not associated with assigned treatment group based on t test. bTotal number of windows in unit marginally associated with assigned treatment group based on t test ( p= 0.0641). cNumber of unpainted windows significantly associated with assigned treatment group based on t test ( p= 0.0088)

2. Baseline Exterior Building and Interior Unit Condition Baseline Exterior Building Deterioration. In order to assess the level of pre existing building deterioration, LAAP inspectors performed an exterior visual assessment of enrolled buildings, checking for seven ( 7) items considered to serve as obvious signs of deterioration ( see Table 4 on page 28). In general, there were minimal observed differences between the LHR and LHR+ W units with respect to most of these exterior deterioration variables. For example, 26 percent of the LHR units had roofs, gutters and downspouts that were either missing, broken, cracked or had holes and 21 percent of the LHR+ W units had similar deterioration. LHR+ W units did, however, differ from LHR units for one particular item of exterior deterioration: 30 percent of the LHR+ W units versus 13 percent of the LHR units had two or more windows or doors that were broken, boarded up or missing. This condition was highly associated with the assigned 11/ 23/ 05 28 treatment group ( p value = 0.006). Given that the LHR+ W units were slated to receive new windows as part of the study, this could explain the difference between the two treatment groups. Units not randomly assigned to treatment groups could affect costs.

Table 4: Units with Exterior Building Deterioration   Pre Intervention Assessment Types of Exterior Building Deterioration ( 91 LHR units, 86 LHR+ W units) LHR # Units (% Units) LHR+ W # Units (% Units) All Units # Units (% Units)

Roofs, gutters, downspouts   missing, broken, holes, cracks 24 ( 26%) 18 ( 21%) 42 ( 24%)

Chimney   cracked, bricks loose or missing, unstable, out of plumb 2 ( 2%) 2 ( 2%) 4 ( 2%)

Walls and siding   large cracks or holes, boards or shingles broken or missing 16 ( 18%) 14 ( 16%) 30 ( 17%)

Windows and doors     two windows or doors broken, missing, boarded upa 12 ( 13%) 26 ( 30%) 38 ( 21%)

Porch or steps   major elements broken, missing, out of plumb 12 ( 13%) 11 ( 13%) 23 ( 13%)

Foundation   major visible cracks, missing materials, unsound 2 ( 2%) 2 ( 2%) 4 ( 2%)

Evidence of exterior ground contaminated with paint chips 33 ( 36%) 30 ( 35%) 63 ( 36%)

Source: Form 02 aBroken/ missing windows & doors significantly associated with assigned treatment group based on Chi square test ( p= 0.006). No other exterior building deterioration item was associated with treatment group.

The number of observed items of exterior building deterioration in LHR units was not appreciably different from the number observed in LHR+ W units ( see Table 5). There was no significant association between the number of exterior deteriorations and the assigned treatment group ( p value= 0.95).

Table 5: Number of Exterior Building Deterioration Items   Pre Intervention Assessment # Items of Exterior Deterioration per Building ( 91 LHR units, 86 LHR+ W units) LHR # Units (% Units) LHR+ W # Units (% Units) All Units # Units (% Units) " 0" items of exterior deterioration 36 ( 40) 29 ( 34) 65 ( 37) " 1" item of exterior deterioration 28 ( 31) 30 ( 35) 58 ( 33) " 2" items of exterior deterioration 14 ( 15) 15 ( 17) 29 ( 16) " 3" items of exterior deterioration 9 ( 10) 7 ( 8) 16 ( 9) " 4" items of exterior deterioration 3 ( 3) 4 ( 5) 7 ( 4) " 6" items of exterior deterioration 1 ( 1) 1 ( 1) 2 ( 1) Source: Form 02 Baseline Interior Dwelling Unit Deterioration. LAAP inspectors also visually assessed the level of pre existing interior dwelling unit deterioration by checking against five ( 5) evaluation items. Here, LHR+ W units had higher percentages of deterioration than the LHR units for four 11/ 23/ 05 29 ( 4) of the five ( 5) items ( see Table 6). Most notably, LHR+ W units were more likely than LHR units to have walls, ceilings, doors and trim that were in need of repair, replacement or repainting, and floors that were loose, cracked, had missing boards or a worn finish, or had deteriorated carpeting. Condition of the floors was significantly associated with the assigned treatment group ( p value = 0.010), while condition of the walls, ceiling, doors and trim was marginally associated with assigned treatment group ( p value = 0.088). A slightly higher percentage of LHR+ W units had interior deterioration caused at least in part by disrepair of heating/ cooling or plumbing systems, while slightly more LHR units had interior deterioration caused by roof leaks. However, neither disrepair of heating/ cooling or plumbing systems nor roof leaks were significantly associated with assigned treatment group. Both LHR and LHR+ W units had a very high percentage of units ( 83.5 percent LHR and 88.4 percent LHR+ W) with at least one room having more than 2 ft2 of paint deterioration on walls, woodwork, doors, windows and other painted surfaces. The mean number of rooms with such paint deterioration was 2.3 rooms in LHR units and 2.6 rooms in LHR+ W units.

Table 6: Units with Interior Dwelling Unit Deterioration   Pre Intervention Assessment Type of Interior Dwelling Unit Deterioration ( 91 LHR units, 86 LHR+ W units) LHR # Units (% Units) LHR+ W # Units (% Units) All Units # Units (% Units)

Walls, ceiling, doors and trim   cracks, need for repair, replace or major repaintinga 36 ( 40%) 45 ( 52%) 81 ( 46%)

Floors   loose, missing or cracked, finish worn, deteriorated carpetingb 45 ( 49%) 59 ( 69%) 104 ( 59%)

Heating/ cooling and plumbing   need for extensive repairc 8 ( 9%) 11 ( 13%) 19 ( 11%)

Interior damage due to roof leak   need for extensive repairc 17 ( 19%) 14 ( 16%) 31 ( 18%)

Rooms with > 2 ft2 of paint deterioration on walls, woodwork, doors, windows, etc. c 76 ( 84%) 76 ( 88%) 152 ( 86%)

Source: Form 02 aCondition of walls, ceilings, doors, & trim marginally associated with assigned treatment group based on Chisquare test ( p= 0.088). bFloor condition significantly associated with assigned treatment group based on Chi square test ( p= 0.010). cThese interior deterioration items not associated with assigned treatment group based on Chi square test.

The total number of observed items of interior deterioration was significantly associated with the assigned treatment group ( p value = 0.0212). The number of LHR units with at least one observed interior dwelling unit deterioration item ( approximately 76 percent) was lower than that of LHR+ W units ( approximately 84 percent) ( see Table 7 on page 30). Interestingly, more LHR units ( 45 percent) than LHR+ W units ( 35 percent) had one item of interior deterioration, but the LHR+ W units were more likely to have two ( 2) or more items of deterioration. 11/ 23/ 05 30 Table 7: Number of Interior Dwelling Unit Deterioration Items   Pre Intervention Assessment Number of Items of Interior Deterioration per dwelling unit ( 91 LHR units, 86 LHR+ W units) a LHR # Units (% Units) LHR+ W # Units (% Units) All Units # Units (% Units)

" 0" items of interior deterioration 22 ( 24%) 14 ( 16%) 36 ( 20%) " 1" item of interior deterioration 41 ( 45%) 30 ( 35%) 71 ( 40%) " 2" items of interior deterioration 20 ( 22%) 29 ( 34%) 49 ( 28%) " 3" items of interior deterioration 7 ( 8%) 11 ( 13%) 18 ( 10%) " 4" items of interior deterioration 1 ( 1%) 2 ( 2%) 3 ( 2%) Source: Form 02 aTotal number of items of interior deterioration significantly associated with assigned treatment group based on Chisquare test ( p= 0.0212).

B. Results of Pre Intervention Composite and Single Surface Dust Sampling As noted above, for most of the enrolled units, LAAP inspectors did not take dust samples when pre intervention visual assessments were performed because a number of initially assessed units ultimately were de enrolled by the property owners and/ or by LAAP before lead hazard reduction specifications and grant applications were submitted and approved. Therefore, some units were de enrolled prior to the collection of dust samples but after pre intervention characterizations were done. To ensure that dust samples were collected no more than four ( 4) weeks prior to the intervention, LAAP inspectors typically obtained composite and single surface samples during a pre construction walk through of the unit with the property owner and, if applicable, the contractor performing the lead hazard reduction work. For this reason, there are fewer units having pre intervention dust sample results ( 148 units) than those with visual assessment results ( 177 units).

1. Pre Intervention Composite Results Composite dust samples were taken from bare floors, interior window sills, window troughs and, when necessary, carpeted floors in all enrolled LHR and LHR+ W units. Because very few units had carpeted floors, sample results for carpeted floors were excluded from this study. A Wilcoxon rank sum test was used to test the equality of the median dust lead loadings for the assigned treatment group ( i. e., LHR versus LHR+ W units). Differences in median preintervention dust lead loadings between the two groups had to be accounted for before the effectiveness of the lead hazard control treatments could be fully evaluated.

For the three ( 3) surface types, the median pre intervention dust lead loadings in the LHR+ W units exceeded median loadings for the LHR units ( see Table 8 on page 31 and Figure 3 on page 32). These differences were significant for bare floors ( p value= 0.0374), marginally significant for window troughs ( p value= 0.1077), but not significant for interior window sills ( pvalue 0.2803). The 5th, 25th, 75th, and 95th percentile dust lead loadings in the LHR+ W units were all higher than those in the LHR units, in some cases dramatically so. 11/ 23/ 05 31 Table 8: Pre Intervention Composite Sample Dust Lead Loading Surface Type LHR Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits LHR+ W Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits Bare floorsa, b ( 73 LHR units, 71 LHR+ W units) 22 77 273 634 5,199 258 173; 385 39 141 333 1,635 23,960 500 325; 768 Interior window sillsa, b ( 74 LHR units, 74 LHR+ W units) 31 631 1,986 8,362 42,619 1,854 1,148; 2,995 286 954 2,780 9,545 101,200 3,153 2,098; 4 737 Window troughsa, b ( 74 LHR units, 74 LHR+ W units) 67 2,050 9,427 38,308 260,182 7,680 4,568; 12,911 740 3,287 10,998 90,480 447,429 16,659 10,142; 27,365 Source: Form 04A aApproximately 95% of bare floor composites, interior window sill composites, and window trough composites were comprised of 4 sub samples; the rest were comprised of either 2 or 3 sub samples. b Based on Wilcoxon rank sum tests, pre intervention dust lead loadings significantly associated with assigned treatment group for floors ( p= 0.0374), marginally associated for troughs ( p= 0.1077), & not associated for sills ( p= 0.2803). 11/ 23/ 05 32 Figure 3: Pre Intervention Composite Sample Dust Lead Loading Box Plot 1 10 100 1000 10000 100000 1000000 LHR Bare Floors LHR+ W Bare Floors LHR Window Sills LHR+ W Window Sills LHR Window Troughs LHR+ W Window Troughs Dust Lead Loading ( ug/ ft^ 2)

Note: Bottom whisker= 5th percentile; top whisker= 95th percentile; box= 25th & 75th percentile; circle= median; triangle = geometric mean.

2. Pre Intervention Single Surface Results As noted in Section II. E, although single surface dust wipe samples were to be collected only in LHR+ W units, both composite and single surface samples were collected in certain LHR units from November 1997 until February 1, 1998 due to laboratory analysis concerns. ( All such LHR units dust sampled during that period had the two sample types collected through Phase II.)

Similar to composites, single surface samples were taken from bare floors, interior window sills, window troughs in designated rooms. ( There were too few carpeted floor samples to allow full characterization of this surface type.) There were more LHR+ W units ( 73) with single surface samples than LHR units ( 25), but the median dust lead loading values in the LHR+ W units again exceeded those of the LHR units by a factor of two to three ( see Table 9 on page 33 and Figure 4 on page 34). Based on Chi square testing, these differences were not significant for bare floors ( p value= 0.1176) or window troughs ( p value= 0.2818), but were highly significant for interior window sills ( p value= 0.0036). The 5th, 25th, 75th, and 95th percentile dust lead loadings were also much higher in the LHR+ W units.

The pre intervention single surface dust sample results for both LHR and LHR+ W units were also compared to pre intervention single surface dust data obtained from Baltimore City housing units enrolled in Round I of the National Evaluation of HUD's OHHLHC's Lead Hazard Control 11/ 23/ 05 33 Grant program. These units underwent lead hazard reduction interventions that were similar to those of the LHR+ W units, and more intensive than those of LHR units. No consistent differences in pre intervention dust lead levels were found to exist between the LHR and LHR+ W treatment groups and the Baltimore Round One units, suggesting that the Round One units could be used to contrast the effectiveness of higher level lead hazard reduction treatments versus the somewhat lower level EA 6 8 prescribed treatments. Pre intervention bare floor dust lead levels for LHR and LHR+ W units were not significantly different than for the Round One units. But pre intervention interior window sill lead levels were lower for LHR units than the Round One units, while LHR+ W units had levels similar to the Round One units. For window troughs, the opposite was observed. Here, the LHR+ W units had significantly higher preintervention dust lead levels than the Round One units.

Table 9: Pre Intervention Single Surface Sample Dust Lead Loading Surface Type LHR Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits LHR+ W Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits Baltimore HUD Unitsa ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits Bare floorsb ( 25 LHR units, 73 LHR+ W units) 29 83 192 881 7,225 293 140; 611 58 154 338 986 29,258 511 335; 779 37 130 314 681 1,955 292 254; 337 Interior window sillsb ( 25 LHR units, 73 LHR+ W units) 41 186 844 1,580 45,179 705 283; 1,755 146 850 2,350 7,303 229,108 2,830 1,790; 4,475 223 832 2,510 7,228 27,470 2,509 2,133; 2,950 Window troughsb ( 25 LHR units, 72 LHR+ W units) 329 2,253 6,135 39,954 98,100 7,795 3,372; 18,020 359 1,949 12,227 92,595 547,652 13,462 7,910; 22,911 136 1,070 3,630 13,000 50,000 3,451 2,807; 4,243 Source: Form 04B aBaltimore HUD unit data are from Baltimore Round One housing units enrolled in the National Evaluation of HUD's Lead Hazard Control Grant Program. For floors, Baltimore HUD unit data include both interior floor and entry floor data. bBased on Wilcoxon rank sum tests, pre intervention single surface dust lead loadings not associated with assigned treatment group for bare floors ( p= 0.1176) or troughs ( p= 0.2818), but significantly associated for sills ( p= 0.0036). 11/ 23/ 05 34 Figure 4: Pre Intervention Single Surface Sample Dust Lead Loading Box Plot Note: Bottom whisker= 5th percentile; top whisker= 95th percentile; box= 25th & 75th percentile; circle= median; triangle = geometric mean.

3. Comparison of Pre Intervention Single Surface Results with Clearance Standards/ Guidance Comparison of pre intervention single surface dust sample results for interior window sills with the Maryland statutory abatement clearance standard and the joint HUD/ EPA guidance clearance standard of 500 µ g/ ft2 yields useful information in terms of statistical association with higher dust lead loading. Assigned treatment group was found to be significantly associated with preintervention interior window sill dust lead loading being above or below a standard of 500 µ g/ ft2 ( p value = 0.009). ( Note: Similar analyses were performed using clearance standards for floors and window troughs, but no statistically significant associations were observed for the assigned treatment group.) In summary, the results of pre intervention exterior and interior visual assessment and composite and single surface dust sampling all indicate that LHR+ W units initially enrolled in the study were in poorer condition than enrolled LHR units, suggesting that assignment of units by property owners into these two categories was not random. Paint lead content was not measured during this study. However, given historical residential lead paint usage patterns in Baltimore City for housing units of similar age to those enrolled in the study, it is unlikely that the lead content of paint in the LHR units was substantially different from that in the LHR+ W units. 1 10 100 1000 10000 100000 1000000 LHR LHR+ W LHR LHR+ W LHR LHR+ W Bare Floors Window Sills Window Troughs Dust Lead Loading ( ug/ ft^ 2) 11/ 23/ 05 35 VIII. IMMEDIATE POST INTERVENTION RESULTS Of the 148 units that had pre intervention dust results available, a total of 121 units ( 57 LHR and 64 LHR+ W) completed lead hazard reduction treatment interventions and a full immediate postintervention assessment, including a visual assessment, collection of cost and concurrent work information and post intervention dust testing. Samples potentially associated with Lab A's unacceptable composite spike sample results were excluded from all analyses ( see Appendix B). The relationship between these post intervention factors and the assigned treatment group ( i. e., LHR versus LHR+ W units) was examined using a Chi square test. A Wilcoxon rank sum test was used to test the equality of the post intervention median dust lead loadings for the assigned treatment group.

A. Results of Immediate Post Intervention Composite and Single Surface Dust Sampling 1. Immediate Post Intervention Composite Results Immediate post intervention composite dust samples were taken from the same surface types and locations as those sampled at pre intervention ( see Table 10 on page 36 and Figure 5 on page 37). For bare floors, immediate composite post intervention median dust lead loadings for LHR and LHR+ W units were not significantly different ( p value= 0.6422). However, as might be expected, immediate post intervention median dust lead loadings for sills and troughs were highly associated with assigned treatment group ( p values= 0.0014 and 0.0001, respectively). The LHR+ W units had much lower median dust lead loadings for interior window sills and window troughs than those in LHR units. 11/ 23/ 05 36 Table 10: Immediate Post Intervention Composite Sample Dust Lead Loading Surface Type LHR Composite Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits LHR+ W Composite Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits Bare floorsa, b ( 51 LHR units, 57 LHR+ W units) 4 15 27 71 195 30 22; 42 4 11 29 58 727 31 21; 46 Interior window sillsa, b ( 54 LHR units, 62 LHR+ W units) 12 27 83 265 1,038 92 62; 135 5 14 36 103 508 36 25; 53 Window troughsa, b ( 54 LHR units, 62 LHR+ W units) 12 174 344 1,100 15,516 416 251; 690 14 30 100 312 1,282 106 72; 156 Source: Form 04A aApproximately 95% of bare floor composites, interior window sill composites, and window trough composites were comprised of 4 sub samples; the rest were comprised of either 2 or 3 sub samples. bBased on Wilcoxon rank sum tests, post intervention composite dust lead loadings were not significantly associated with assigned treatment group for bare floors ( p= 0.6422), but highly associated for sills and troughs ( p= 0.0014 and 0.0001, respectively). 11/ 23/ 05 37 Figure 5: Immediate Post Intervention Composite Sample Dust Lead Loading Box Plot 1 10 100 1000 10000 100000 LHR LHR+ W LHR LHR+ W LHR LHR+ W Bare Floors Window Sills Window Troughs Dust Lead Loading ( ug/ ft^ 2)

Note: Bottom whisker= 5th percentile; top whisker= 95th percentile; box= 25th & 75th percentile; circle= median; triangle = geometric mean.

2. Reduction in Composite Results from Pre to Immediate Post Intervention Large median percent decreases and median µ g/ ft2 decreases were observed when measuring the change from pre to post intervention dust lead loading results for composite samples taken from bare floors, interior window sills and window troughs, with the most dramatic decreases being observed for sills and troughs ( see Tables 11 and 12 on page 38, and Figure 6 on page 39). The association between the percent reduction in composite dust lead loadings and the assigned treatment group was highly significant for interior window sills ( p value= 0.0001) and troughs ( pvalue 0.0001) but was not significant for bare floors ( p value= 0.2459). 11/ 23/ 05 38 Table 11: Percent Reduction in Pre to Immediate Post Intervention Composite Dust Lead Loadings Surface Type and Statistic Composite Dust Samples LHR Units Pre to Post Intervention Percent Reduction LHR+ W Units Pre to Post Intervention Percent Reduction Bare floors ( 49 LHR, 56 LHR+ W) a: 25th Percentile Percent Decrease Median Percent Decrease 75th Percentile Percent Decrease 70 85 93 74 89 97 Interior window sills ( 52 LHR, 62 LHR+ Wa 25th Percentile Percent Decrease Median Percent Decrease 75th Percentile Percent Decrease 78 94 98 96 99 > 99 Window troughs ( 52 LHR, 62 LHR+ W) a 25th Percentile Percent Decrease Median Percent Decrease 75th Percentile Percent Decrease 74 95 98 97 > 99 > 99 Source: Form 04A aBased on Wilcoxon rank sum tests, percent reduction in composite dust lead loadings was significantly associated with assigned treatment group for sills ( p= 0.0001) and troughs ( p= 0.0001) but not for bare floors ( p= 0.2459).

Table 12: Micrograms Per Square Foot Reduction in Pre to Immediate Post Intervention Composite Dust Lead Loadings Surface Type and Statistic Composite Dust Samples LHR Units Pre to Post Intervention µ g/ ft2 Reduction LHR+ W Units Pre to Post Intervention µ g/ ft2 Reduction Bare floors ( 49 LHR, 56 LHR+ W): 25th Percentile µ g/ ft2 Decrease Median µ g/ ft2 Decrease 75th Percentile µ g/ ft2 Decrease 40 147 506 71 225 807 Interior window sills ( 52 LHR, 62 LHR+ W: 25th Percentile µ g/ ft2 Decrease Median µ g/ ft2 Decrease 75th Percentile µ g/ ft2 Decrease 415 1,686 8,272 716 2,596 7,433 Window troughs ( 52 LHR, 62 LHR+ W): 25th Percentile µ g/ ft2 Decrease Median µ g/ ft2 Decrease 75th Percentile µ g/ ft2 Decrease 1,230 9,708 25,175 4,254 11,284 90,424 Source: Form 04A 11/ 23/ 05 39 Figure 6: Pre and Immediate Post Intervention Composite Sample Dust Lead Loading for LHR and LHR+ W Units ( Logarithmic Scale)

1 10 100 1000 10000 100000 1000000 Pre Int.

Post Int.

Pre Int.

Post Int.

Pre Int.

Post Int.

Pre Int.

Post Int.

Pre Int.

Post Int.

Pre Int.

Post Int.

LHR LHR+ W LHR LHR+ W LHR LHR+ W Bare Floors Window Sills Window Troughs Dust Lead Loading ( ug/ ft^ 2)

Note: Bottom whisker= 5th percentile; top whisker= 95th percentile; box= 25th & 75th percentile; circle= median; triangle = geometric mean.

3. Units Having an Increase in Composite Dust Lead Loadings from Pre to Immediate Post Intervention Despite the significant median decreases in dust lead loadings between pre and immediate postintervention data in Table 13 on page 40 show that some units experienced increases in dust lead loadings between these two phases. The percentage of LHR+ W units that underwent an increase was generally lower than that of LHR units. 11/ 23/ 05 40 Table 13: Number and Percent of Units Having an Increase in Composite Dust Lead Loadings from Pre to Immediate Post Intervention Surface Type and Sample Type LHR LHR+ W Bare Floors: 6/ 49 ( 12%) 3/ 56 ( 5%)

Interior window sills: 4/ 52 ( 8%) 2/ 62 ( 3%)

Window Troughs: 3/ 52 ( 6%) 1/ 62 ( 2%)

4. Immediate Post Intervention Single Surface Results As previously noted, single surface dust samples taken in all 62 LHR+ W units and in 20 LHR units were also included in this sampling subset ( see Table 14 on page 41). With this in mind, although the median immediate post intervention single surface dust lead loading for bare floors in LHR units was higher than that in LHR+ W units, this difference was not significant ( pvalue 0.2168). However, as might be expected, single surface immediate post intervention median dust lead loadings for sills and troughs were highly associated with assigned treatment group ( p values= 0.0012 and 0.0035, respectively). The LHR+ W units had much lower median dust lead loadings for interior window sills and window troughs than those in LHR units.

Immediate post intervention single surface dust sample results for both LHR and LHR+ W units were compared with immediate post intervention single surface dust data obtained from Baltimore city housing units enrolled in Round One of the National Evaluation of HUD OHHLHC's Lead Hazard Control Grant Program. These units underwent interventions that were similar to those of LHR+ W units and generally more intensive than those of LHR units. ( see Table 14 on page 41 and Figure 7 on page 42). Median dust lead loading results for bare floors, interior window sills and window troughs were all much lower in the Baltimore Round One units than in both the LHR and LHR+ W units. Each surface type comparison was found to be highly significant ( p value= 0.0001 for each). 11/ 23/ 05 41 Table 14: Immediate Post Intervention Single Surface Dust Lead Loading Results Surface Type LHR Single Surface Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits LHR+ W Single Surface Dust Lead Loading ( µ g/ ft2) 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits Baltimore HUD Units Single Surface Dust Lead Loading ( µ g/ ft2) a 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Geometric Mean 95% Confid. Limits Bare floorsb, c ( 20 LHR units, 63 LHR+ W units) 10 26 66 112 1217 60 34; 109 6 20 39 89 307 43 31; 59 0.3 5 15 35 96 14 12; 16 Interior window sillsb, c ( 20 LHR units, 62 LHR+ W units) 14 33 103 178 961 96 51; 178 7 15 29 51 257 32 24; 42 0 2 10 31 103 17 15; 20 Window troughsb, c ( 20 LHR units, 62 LHR+ W units) 29 217 610 1,139 5,071 460 230; 921 9 32 115 347 2,262 128 79; 207 0 6 38 125 607 57 47; 68 Source: Form 04B aBaltimore HUD unit data are Round I data from the National Evaluation of HUD's Lead Hazard Control Grant Program and were compiled using initial Phase 2 data ( immediate post intervention). For floors, Baltimore HUD unit data include both interior floor and entry floor data. bBased on Wilcoxon rank sum tests, median post intervention single surface dust lead loadings with significantly associated with assigned treatment group for sills ( p= 0.0012) and troughs ( p= 0.0035), but not associated for bare floors ( 0.2168). cBased on Wilcoxon rank sum tests, median post intervention single surface dust lead loadings for Baltimore Round 1 units were significantly lower than those for study units ( p= 0.0001 for each surface type). 11/ 23/ 05 42 Figure 7: Immediate Post Intervention Single Surface Dust Lead Loading Results Box Plot 1 10 100 1000 10000 LHR LHR+ W LHR LHR+ W LHR LHR+ W Bare Floors Window Sills Window Troughs Dust Lead Loading ( ug/ ft^ 2)

Note: Bottom whisker= 5th percentile; top whisker= 95th percentile; box= 25th & 75th percentile; circle= median; triangle = geometric mean.