ＦＤＡは BPA が安全だとする２つの研究を上げているが、米国プラスチック製品協議会によって資金提供された研究であることが問題視されている。
Safety of Water Bottles, Baby Bottles Questioned
New Evaluation Shows Some Lingering Concern About Widely Used Chemical BPA
By KATE BARRETT Arpil 15, 2008
Reusable plastic water bottles may be good for the environment, but a new study shows they might be bad for your health
There's a possibility that the chemical found in plastic water bottles, baby bottles and the lining of many food, drink and baby formula cans could be linked to health problems, including prostate cancer, breast cancer and early-onset puberty, according to a chemical evaluation released Monday night by the Department of Health and Human Services' National Toxicology Program.
The evaluation doesn't reverse any opinions about the chemical but simply raises new concerns.
The draft brief found some worry that exposure to the chemical bisphenol A, known as BPA, could have neural and behavioral effects on fetuses, infants and children at existing exposure levels.
"The possibility that bisphenol A may alter human development cannot be dismissed," the evaluation noted.
Indeed, the study failed to put to rest long-standing worries about whether the widely used chemical is safe, and ensures that scrutiny of the Food and Drug Administration's decision to approve BPA will continue. While some have argued the chemical is associated with health risks, the FDA and industry experts have stood by their controversial conclusion that the chemical is not harmful.
The chemical helps make plastic tough and shatter-resistant; the plastic is used in food and drink containers, bike helmets, dental sealants and more.
At the American Chemistry Council, Steve Hentges, executive director of the polycarbonate/BPA global group, said today that there's still no evidence of serious health risks or need to remove BPA from the market. This evaluation echoes many of the already published findings about BPA, Hentges said.
"In every case, what they point out is that the existing data provide only limited evidence for those health effects," he said. "It suggests additional research is needed in some areas, and we don't disagree with that at all.
"But the data as it currently stands does not indicate that there is a significant risk associated with bisphenol A."
But others said Tuesday that the evaluation is a critical development.
"This corrects the scientific record," said Anila Jacob, senior scientist at Environmental Working Group, an organization that has routinely spoken out against the chemical. "It breaks new scientific ground. This is significant."
The Politics of Baby Bottles
Concern about BPA is not confined to the United States. Canada has just officially labeled BPA as dangerous, according to today's Globe and Mail, which could prompt a broad ban or restrictions.
In the United States, caregivers, medical experts and lawmakers alike have questioned the FDA's decision to approve the chemical, contending that the agency made the wrong call.
While the FDA points to two studies showing BPA is safe, several congressional Democrats charge that the research on which the FDA relied was funded by the American Plastics Council.
Since then, lawmakers have been eager to find out whether the FDA is too close for comfort with the industry it regulates at the expense of public health.
"These findings of BPA's dangers are based on the totality of research around this chemical," said Rep. John D. Dingell, D-Mich., chairman of the House Committee on Energy and Commerce, in a Tuesday statement. "These assessments fly in the face of the FDA's determination that BPA is safe."
The congressman wrote a letter to FDA commissioner Andrew von Eschenbach April 4, asking him to provide more information about the decision by April 22.
"Federal regulatory panels do not want to acknowledge the reality that who pays for science makes a difference," charged Frederick Vom Saal, a reproductive biologist and endocrinologist at the University of Missouri who first studied BPA as a sex hormone.
Vom Saal hopes that today's evaluation will prompt the FDA to look more closely at the science that shows BPA could be harmful. "What we're beginning to see is a convergence of opinions on this from various agencies," he said.
New mothers like Sarah Janssen believe it's best to limit exposure to BPA. Janssen, a science fellow at the Natural Resources Defense Council, actively avoided eating canned food and drinking canned sodas while pregnant to limit her exposure to the chemical often found in the products' linings. She also makes sure to use baby bottles, dishes and bowls that don't contain the chemical for her 8-month-old daughter.
"Although all those exposures by themselves are small, they add up in a day's time," Janssen said. "My evaluation of the research has really made me want to limit her exposure, and my exposure when I was pregnant, to this chemical."
"It affects babies a lot more than it would adults," said Ron Vigdor, CEO of Born Free, a company that manufactures BPA-free baby bottles. "I think that parents frankly are scared. Some of the parents are horrified at finding out that baby products could be leaching products and hurting their children."
Chemical evaluations like the one released this week are used to guide state and federal regulators in setting standards for exposure to the chemical, as well as for cleanup procedures.
The chemical evaluation of BPA is a draft open for public comment. The report will be reviewed by other scientists at a meeting in North Carolina this June.
ABC News' Brian Hartman contributed to this report.
DRAFT NTP BRIEF ON BISPHENOL A
[CAS NO. 80-05-7]
April 14, 2008
Peer Review Date: June 11, 2008
The NTP concurs with the conclusion of the CERHR Expert Panel on Bisphenol A that there is some concern for neural and behavioral effects in fetuses, infants, and children at current human exposures. The NTP also has some concern for bisphenol A exposure in these populations based on effects in the prostate gland, mammary gland, and an earlier age for puberty in females.
The scientific evidence that supports a conclusion of some concern for exposures in fetuses, infants, and children comes from a number of laboratory animal studies reporting that “low” level exposure to bisphenol A during development can cause changes in behavior and the brain, prostate gland, mammary gland, and the age at which females attain puberty. These studies only provide limited evidence for adverse effects on development and more research is needed to better understand their implications for human health. However, because these effects in animals occur at bisphenol A exposure levels similar to those experienced by humans, the possibility that bisphenol A may alter human development cannot be dismissed.
The NTP has negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects or reduced birth weight and growth in their offspring.
In laboratory animals, exposure to very high levels of bisphenol A during pregnancy can cause fetal death and reduced birth weight and growth during infancy. These studies provide clear evidence for adverse effects on development, but occur at exposure levels far in excess of those experienced by humans. Two recent human studies have not associated bisphenol A exposure in pregnant women with decreased birth weight or several other measures of birth outcome. Results from several animal studies provide evidence that bisphenol A does not cause birth defects such as cleft palette, skeletal malformations, or grossly abnormal organs.
The NTP concurs with the conclusion of the CERHR Expert Panel on Bisphenol A that there is negligible concern that exposure to bisphenol A causes reproductive effects in non-occupationally exposed adults and minimal concern for workers exposed to higher levels in occupational settings.
Data from studies in humans are not sufficient to determine if bisphenol A adversely affects reproduction when exposure occurs during adulthood. A number of studies, when considered together, suggest a possible effect on reproductive hormones, especially in men exposed to higher levels of bisphenol A in the workplace. Laboratory studies in adult animals show adverse effects on fertility, estrous cycling, and the testes at exposure levels far in excess of those experienced by humans. A number of other effects, such as decreased sperm counts, are reported for the reproductive system at lower doses in animals exposed only during adulthood, but these effects have not been shown to be reproducible. Laboratory animal studies consistently report that bisphenol A does not affect fertility.
These conclusions are based on information available at the time this brief was prepared. As new information on toxicity and exposure accumulates, it may form the basis for either lowering or raising the levels of concern expressed in the conclusions.
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