Wednesday, January 16, 2008

California: The phthalate folly

In addition to the remarks below, readers might want to look at this study, which even suggests that phthalates may be beneficial in some ways

When Gov. Arnold Schwarzenegger signed a statewide ban in October on children's toys that contain more than minuscule amounts of chemicals called phthalates, he was simply carrying on a California tradition of misguided, often damaging "health" regulations. This is, after all, a state that requires most commercial establishments, from supermarkets to pet stores to hotel lobbies, to display "Proposition 65" signs proclaiming that customers are being exposed to trace amounts of chemicals that can cause cancer or birth defects.

Now, Sen. Dianne Feinstein (D-Calif.) is eager to expand California's folly to the entire nation. Undeterred by the judgment of experts but swayed by a few experiments with rats and a single flawed epidemiological study, Feinstein has introduced a bill that would ban six types of phthalates in toys. These chemicals are widely used to soften plastic toys and are found in shower curtains, traffic cones and scores of other common items. They also have crucial applications in surgical instruments and intravenous tubing.

Unfortunately, Feinstein's legislation ignores the basic principles of toxicology. For starters, a rat's metabolism differs significantly from a human's. Although rat studies may be useful for suggesting what sorts of toxicity to look for in humans, often they do not predict effects on humans. Indeed, the toxicity of phthalates in rats appears not to be replicated in humans or other primates.

Second, the dose makes the poison. This means that the mere presence of something in the body does not imply harm; one needs to know the dose and length of exposure, what the substance does (if anything) in the body, how it is disposed of and so forth. Virtually any substance, including water, can be toxic at high enough levels. Consider an example taught to all medical students. Part of the work-up for hypertension (high blood pressure) is to inquire whether the patient eats large amounts of licorice, which contains glycyrrhizin, a chemical that promotes sodium and fluid retention and raises blood pressure.

Extremely versatile and cost-effective, phthalates have been rigorously studied in the U.S. and Europe. A panel of scientists chaired by former Surgeon General C. Everett Koop reviewed the scientific literature on phthalate exposure in 1999. "[Phthalate-containing] toys and medical devices are safe," said Koop. "The panel's findings confirm what the U.S. Food and Drug Administration and the Consumer Product Safety Commission have been saying about these products all along. There is no scientific evidence that they are harmful to children or adults."

Numerous studies have shown that human exposure to phthalates under ordinary circumstances is low and harmless. In fact, according to a review performed by the National Institutes of Health, the source of about 85% to 90% of phthalate exposure in adults, and 44% to 60% in infants, is not toys or consumer products but food. Nor are phthalates harmful even at high levels of exposure -- in patients undergoing regular hemodialysis or oxygenation of their blood in an intensive-care unit, for example.

The Consumer Product Safety Commission rejected a national ban on vinyl toys in 2003, after calculating likely exposure to diisononyl phthalate (DINP), the most common phthalate in children's toys. The total time babies from 3 months to 12 months spend mouthing objects is about 10 minutes an hour. Pacifiers (which do not contain phthalates)account for most of babies' sucking time, with their own body parts next. Soft vinyl toys containing DINP were sucked on for under 11 seconds an hour, or under 5 minutes a day. Even those whose sucking was in the 99th percentile were chewing on their DINP-containing toys for no more than 12 minutes a day. The Consumer Product Safety Commission concluded that a baby would have to suck about 10 times as long before he or she could consume enough DINP to have any potential adverse effects.

International scientists agree. In 2003, for example, the European Union's Institute for Health and Consumer Protection concluded in a risk assessment: "The end products containing DINP (clothes, building materials, toys and baby equipment) and the sources of exposure (car and public transport interiors, food and food packaging) are unlikely to pose a risk for consumers (adults, infants and newborns)." Despite the reassuring risk assessments, politicians overruled them, and the EU instituted a "permanent" ban on phthalates in children's toys in 2005.

The public is harmed when lawmakers proscribe the use of a product that has been proved safe and useful. Inevitably, manufacturers will turn to -- and consumers will be exposed to -- alternatives that are likely to be less well tested. Simply put, Feinstein's bill represents bad science, bad law and disregard for the public interest.


Children exposed to lead 'at risk of Alzheimer's'

Children exposed to lead in old paint, Victorian water pipes and unsafe toys could be at risk of Alzheimer's later in life, scientists have said. A study shows that even small amounts of the dangerous metal in the first few years can cause changes in the brain associated with the devastating disease.

Although lead has been banned in petrol and paint, it is still present in older buildings. Last year, millions of toys imported from China were recalled after tests showed they were made with lead paint. The Alzheimer's Society warned, however, against overreacting to the findings, which came from a study of monkeys.

A spokesman said there was no proof that lead exposure caused the disease. The U.S. researchers behind the study say their work shows that lead has toxic side effects that can appear decades after children are exposed. "We're not saying that lead exposure causes Alzheimer's disease, but it's a risk factor," Dr Nasser Zawia of the University of Rhode Island in Kingston told the New Scientist.

His team fed infant formula milk laced with low doses of lead to baby monkeys - and then followed their progress for 23 years. Although the animals did not show any symptoms of dementia, a post mortem of their brains revealed plaques - harmful deposits of protein normally found in Alzheimer's patients.


Comment below from Panic Watch:

Pertinent details of the study which didn't make it above the fold:

The study was performed on monkeys, not humans. But of course the headline doesn't read 'Monkey children exposed to lead at risk of Alzheimer's.'--that's definitely not as exciting.

The Alzheimer's Society has reacted to this study by saying that there is no proof that lead exposure caused the disease. This is correct. One of the scientists leading the study even told the media: "We're not saying that lead exposure causes Alzheimer's disease."

Even then, "the animals did not show any symptoms of dementia, a post mortem of their brains revealed plaques - harmful deposits of protein normally found in Alzheimer's patients." So the monkeys showed no symptoms of Alzheimer's; they merely had protein deposits that are present in many people after death--both with and without Alzheimer's.


Just some problems with the "Obesity" war:









9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

Even statistical correlations far stronger than anything found in medical research may disappear if more data is used. A remarkable example from Sociology:
"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correlation coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."
So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.

"What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!


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