Concerns about BPA stem from studies in lab animals and cell cultures showing it can mimic the hormoneestrogen. It is considered an“endocrine disruptor,” a term applied to chemicals that can act like hormones. But whether it does any harm in people is unclear.
Where science has left a void, politics and marketing have rushed in. A fierce debate has resulted, with one side dismissing the whole idea of endocrine disruptors as junk science and the other regarding BPA as part of a chemical stew that threatens public health.
About half a dozen states have banned BPA in children’s products, and SenatorDianne Feinsteinhopes to accomplish the same nationwide, with an amendment tothe food safety billscheduled for a vote in the Senate next week.
This year, apresidential panel on cancer and the environmentsaid there was a“growing link” between BPA and several diseases, includingcancer, and recommended ways to avoid BPA, like storing water in bottles free of it and not microwaving food in plastic containers. Some cancer experts said the report overstated the case against chemicals, but the concerns it raised seemed to reflect growing public worries.
Consumer fears have made the words“BPA-free” a marketing tool. Wal-Mart, Whole Foods, Sears, CVS and other retailers have said they will stop selling baby bottles made with BPA, and major formula and baby-bottle manufacturers have also scrapped it. Worried people have purged their homes of plastics labeled 7. (Products are numbered for recycling; those with BPA carry a 7, but not everything with a 7 contains BPA). Nalgene, which makes popular water bottles, quit using BPA when customers began complaining about it. Sunoco, one of the companies that makes BPA, said it would sell the chemical only to buyers who guaranteed that they would not use it in food or drink containers meant for children.
In May, aWhite House task force on childhood obesityissued a report suggesting that BPA and certain other chemicals might be acting as“obesogens” in children— promoters ofobesity— by increasing fat cells in the body and altering metabolism and feelings of hunger and fullness.
Perhaps not surprisingly, the issue of whether BPA is safe has become highly partisan.
Environmental groupsand many Democrats want BPA banned, blaming it for an array of ills that includes cancer, obesity, infertility and behavior problems. Environmentalists think the United States should adopt the“precautionary principle,” a better-safe-than-sorry approach favored in theEuropean Union. The principle says, in essence, that if there are plausible health concerns about a chemical, even if they are not proved, people should not be exposed to it until studies show it is safe. The United States takes the opposite approach: chemicals are not banned unless there is proof of harm.
Many Republicans, anti-regulation activists and thefood-packagingandchemical industriesinsist that BPA is harmless and all but indispensable to keeping canned food safe by sealing the cans and preventing corrosion, and to producing many other products at reasonable prices. They argue that the chemical has been demonized, and that adopting the precautionary principle would lead to needless and ruinously expensive bans on safe and useful products. Both sides are closely watching the issue unfold, because BPA is widely seen as a test case in an era of mounting worry about household chemicals, pollution and the possible links between illness and environmental exposures, especially in fetuses and young children.
“This isn’t the only endocrine-disrupting chemical on the block,” said Patricia Hunt, a biologist atWashington State University, in Pullman.“It’s just the one that’s captured the attention, because researchers like me have gotten into the field and gone,‘Holy cats! We’re all exposed to this.’ There’s been a heavy industry response, and we’ve gathered our forces together a little more strongly to shine a light on it. This is the poster child for this group of chemicals. Academic scientists are saying we need to do something, and we need to do it fast.”
Linda S. Birnbaum, director of the National Institute of Environmental Health Sciences (part of theNational Institutes of Health), said that a new round of government-financed studies with uniform methods, now under way with animal subjects, should help to resolve unanswered questions. In the meantime, Mrs. Feinstein’s ambitious plan to ban BPA from baby bottles, sippy cups, baby food and formula was blocked by partisan battling. She had hoped that the ban would be included in thefood safetybill, not merely in an amendment to be considered separately.
But after months of wrangling, she gave up. The food industry, mostly supportive of the food bill, threatened to oppose it if the BPA provision got in. So did many Republican senators. In August, Mrs. Feinstein’s Democratic colleague RepresentativeJohn D. Dingellof Michigan made public a letter in which he urged her to back off on BPA for the sake of the bill, which will broaden the authority of theFood and Drug Administrationover the food supply— a measure widely seen as essential to reducing food-borne illnesses like the recentsalmonellaoutbreak from eggs.
In a statement released in August, Mrs. Feinstein said,“TheFood SafetyBill was the logical place for this legislation, and I have been working hard to reach a compromise, but unfortunately BPA language is not included.”
As an amendment instead of being part of the bill itself, the ban is far less likely to pass the Senate and become law. Last week, the legislature in Mrs. Feinstein’s state, California, rejected a BPA ban like the one she is proposing.
Buried in an Avalanche of Data
The mountains of data produced so far show conflicting results as to whether BPA is dangerous, in part because different laboratories have studied the chemical in different ways. Animal strains, doses, methods of exposure and the results being measured— as crude as body weight or as delicate as gene expression in the brain— have all varied, making it difficult or impossible to reconcile the findings. In science, no experiment is taken seriously unless other researchers can reproduce it, and difficulties in matching BPA studies have led to fireworks.
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