Canada, Painting the Country Green
When a group of US senators including Richard J. Durbin (D-Ill.), Dianne Feinstein (D-CA), John F. Kerry (D-MA) and Robert Menendez (D-NJ), joined Charles Schumer (D-NY) last spring to sponsor a bill that would disallow the sale of products containing bisphenol A (BPA) for children under 7, a Canada newspaper commented that the US must have been "emboldened" by Canada's recent action on Bisphenol A (BPA). Two weeks before, on April 19th, Health Canada and Environment Canada had jointly proposed a ban on products like polycarbonate baby bottles made with bisphenol A. Canadians proudly declared themselves "the first country in the world to take such action to limit exposures to bisphenol A".
Canadian retailers quickly hopped on a growing bandwagon to stop selling BPA containing products. Walmart and three other major retail groups announced they would stop selling polycarbonate baby bottles, thus joining ranks with Canadian retailers who had already volunteered to stop their sales. Individual towns also caught the BPA ban spirit; Canadian municipalities from Vancouver to the "model town" of Kapuskasing, Ontario began pulling bisphenol A containing plastic containers off the shelves.
Canada's First Mover Status. Oh, Sacrifice
There's plenty of room for congratulating Canada on its first regulator status, but there's also some background. We've followed the science and politics of bisphenol A for a few years and with BPA (and everything else, as you very well know), politicians seem violently allergic to being "the first" to suggest regulating any product or chemical. For obvious reasons, no politician is a maverick. The economy, business, personal reputation, and lack of comfort with science, combined with lack of attention from the public, give politicians a handy (and sometimes reasonable) excuse to lag several paces behind the leading edge of science. Real mavericks don't get second terms.
When the public brings an issue like bisphenol A to the attention of cities like San Francisco, states like California, and US regulatory agencies like the FDA, these entities promise to limit the sale of bisphenol A. They quickly back down when faced with industry threats or lawsuits. At state, city and federal levels, when curious reporters ask politicians later why they backed down BPA, they tend to mumble incoherently into their hands, if they answer at all.
Last year for instance, San Francisco, California proudly proclaimed itself the "first city to ban bisphenol A". The chemical and toy lobbies promptly sued, whereupon San Francisco's political bravado melted away like gelato on the 110 degree day that its legislators will never encounter in their town. San Francisco immediately dropped the legislation, but maintained their elevated reputations as protectors of children's health because the press headlines heralding their fleeting bravery stuck in black and white. (Except at Acronym Required where we amended the titles and introductions of all our blog posts to accommodate the city's mercurial fortitude).
I don't doubt that Canadian politicians are just as calculating as American politicians. For the past 15-20 years, Bisphenol A research showing convincing deleterious health effects has accumulated. Although Canada's "first" is commendable, it could taken with a grain of salt.
And is being "first" even relevant? The US and Canada have entirely different economic considerations that influence and shape political will. Consider Canada's overall economic investment in bisphenol A, compared to that of the US. According to the Canadian April 19, 2008 report, in 2003, worldwide production of BPA was about 3 billion kilograms per year. As recently as 1986 Canada manufactured or imported 12 million kilograms of bisphenol-A per year. However, today, Canada only uses .5-1.5 million imported kilograms(kg) a year and the country has stopped manufacturing bisphenol A altogether. By contrast, in the US production increased from 7.3 million kg in 1991, to 1 billion kg in 2004. It's not surprising that Canada would be less reluctant to ban BPA, they have less of a commercial stake in the chemical.
On BPA, The US and Human Health vs. Canada's Health and Environment Concerns
One notable difference between Canada's approach to BPA and that of the United States is the separation of agencies that decide US policy. The Canadian ministers from two agencies, Health Canada and Environment Canada, issued a joint statement of concern in April, based on the research on health and the environment, stating that bisphenol A was a "toxic chemical".
The weight of the environmental evidence against BPA is strong. Researchers can measure BPA that collects in brackish low-oxygen waters and see the direct effects on species that live in those waters. By contrast, human health data is sparse. There are few studies in humans because of the obvious barrier to "testing" humans by asking them to ingest a obviously toxic chemical. In rats, there are lots of studies and the conclusions are more solid. At very low doses scientists find BPA causes deleterious developmental effects.
Canada'a decision rests heavily on environmental data in addition to the health concerns. This is different from the US, where the government's primary focus, at the National Toxicology Program (NTP), the Food and Drug Administration (FDA), and the Environmental Protection Agency (EPA), is how BPA effects human health. While the expert panel of 38 scientists who evaluated bisphenol A research published in 700 of studies was sponsored in part by the EPA and was significantly alarming, the results focused on humans and were quickly confused when other agencies published simultaneous conflicting results.
Critics quickly linked the different results to the institutions affiliations of the researchers -- industry or academic or government. These differing results have become a hot-button issue for many people. Industry research in bisphenol A frequently arrives at the opposite conclusion of government research and is sometimes not peer-reviewed or has control problems.Indeed, some commenters skip over real scientific uncertainties involved with BPA research, the diversity of various experiments and the difficulties in determining effects, and unilaterally cast blame on "industry research". However damning this pattern seems, all "industry research" should not be tainted.
It's more important to keep focus on the evidence and for the public to grapple with the real uncertainties yet be able to recognize the relentless BPA industry fronted marketing for what they are. Subtle and confusing perhaps, but key to understanding the real dangers of BPA and other toxins.
BPA research is fraught with experimental difficulty which effects the interpretation of results. Bisphenol A shows biphasic effects depending on the dose, so high doses show dramatic negative effects, and low doses show subtle but important effects, while medium doses often show fewer effects, presumably because the receptors are overwhelmed or the effects masked. Additionally there is uncertainty based on arcane experimental criteria -- the delivery method for bisphenol A dietary or injected, the type of experiment -- cell culture or rat, if rat, the breed, the brand of rat chow its fed, the type of labware used to do the experiment, the source of BPA tested -- blood, breast milk, urine, tissues, air, water, dust. That's only the beginning.
But there's a consistent pattern of BPA research showing widespread effects on health. In the past couple of years ordinary citizens who care about their own exposure have aggressively asked questions of industry, legislators and science, and are concluding that the growing body of bisphenol A research shows consistent and disturbing implications for on systems such as behavior, neurobiology, development, and other systems.
No matter how fast the evidence piled up, plastic lobbyists have leveraged the different results from disparate agencies adeptly. Animal data shows toxicity of BPA which persists in the environment. But industry lobbyists actually use the prolific animal results to bolster their claims by saying that deleterious BPA studies have only been shown in animals, but not humans. In the US there's not a lot of public talk about the effects of BPA on species other than humans.
Canada's Minister Baird said in his statement about the BPA decision:: "When it comes to Canada's environment, you can't put a price on safety". However this too can be evaluated differently depending on your perspective. Canada has heartily embarked on other projects such as the Alberta oil sands, that aren't so congenial to the environment. Baird's statement presents a conflicting image for the country's true commitment to the environment, given the economics of BPA.
At least for a moment last spring, though Canada was proudly "first" on BPA. Hopefully the rigors of comment periods, legislation drafting, and enforcement follow-through will cement its place. In the meantime, Europe and the US follow haltingly along.
US Agencies Dither
Despite the necessary constraints to doing toxicity research on human subjects, studies in mice and cell cultures show myriad changes to genital tract development, breast and prostate tissues, sexual differentiation, endocrine and immune systems, behavior, and neural development, all at doses below what the FDA deems safe. Yet an NIH interagency group assures us doesn't cause human health effects.
At the same time Canada issued it's dual agency warning, the US National Toxicity Program released their April, 2008 (NTP) report, stating the agency's reconsideration of BPA safety. The US National Toxicology Program's (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) announced a slightly revised conclusion about BPA from their November, 2007 report, criticized by experts in the field. The April report reconsidered their 2007 report (just finalized this September) and concluded there was "negligible" concern for many exposures, and "some concern" for neural and behavioral effects in fetuses, infants, and children.
However the April, 2008 report added: "the possibility the bisphenol A could alter human development cannot be dismissed". The authors repeated the statement 3 times, which is pertinent, given the otherwise understated tone. The report included papers that the previous group had left out because of methodology, with the explanation that scientists could get meaning from the research even if the questions addressed in studies were not necessarily aimed at discerning overall BPA safety to humans. It was also much more accessible to non-science readers then the previous report.
Despite the overall reassuring stance of the April NTP report however, it's clear that ample concern (or action), and further research is justified. Take for instance the conclusion of "negligible concern" that exposure to bisphenol A would cause birth defects. The evidence is based on, as the NTP scientists put it: "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." If you get past the reassuring "negligible" stamp, the actual data is not reassuring. These particular birth defects are the most conspicuous ones that could effect fetal mice, aside from quick death. However the results don't prove that less conspicuous but serious and debilitating birth defects would not occur.
While the chemical industry likes to point out that the results in mice wouldn't occur in humans, you could just as easily argue that not observing a "gross organ malformation" in a fetal mouse would not rule out the possibility of other very serious birth defects could occur in both mice and humans and not appear as gross malformations. The dearth of more conclusive safety evidence in humans, therefore, more than warrants the NTP's April warning, however understated, that "the possibility that bisphenol A may alter human development cannot be dismissed". Nevertheless, their authoritative opinion assures people that the chemical is safe. This opinion serves as a nice soundbite and marketing fodder for the Chemical and Plastics industries.
JAMA Steps In
We should point out that the hesitation to take precautions about BPA in light of extensive (animal) research extends beyond politicians. Several recent books detail the dangers of many environmental toxins but exclude any mention of bisphenol A. Scientists' warnings about bisphenol A have been countered vehemently by seemingly trustworthy organizations like the American Dental Association. To confuse matters more, the press takes a less than informative approach in covering bisphenol A, regularly calling on the ultra-self-interested American Chemical Council lobby group for plastics to answer safety questions. All of this befuddles citizens, who don't know whether to invest in glass baby bottles or just keep microwaving the trusty plastic ones they've depended on all these years.
Because of all the questions surrounding BPA and pressures from citizens, quite a few representatives in congress are tripping all over themselves to investigate the chemical and the agencies which should be overseeing its use. At some point the momentum of an issue catches up with those who stall and demands unified response. Congress is starting to question the FDA about its procedures for evaluating BPA.
While Canadians make small jabs about the newly "emboldened" Americans, who, it's true, only now, are beginning to introduce new legislation, most of which has been resoundingly defeated. However US politicians are quickly catching up.
Adding medical weight to the issue this week, the Journal of the American Medical Association, (JAMA), yesterday published what was billed by some as the "first human data on BPA". The study looked at urinary levels of BPA and found increased incidence of cardiovascular disease, type 2 diabetes, and liver-enzyme abnormalities in adults with elevated BPA levels. The study was by no means the robust proof needed to show long term effects from BPA exposure indicated in the low-dose research, however the researchers and accompanying editorial by BPA expert Frederick S. vom Saal emphasize that these results are consistent with animal and cell culture data and will hold up with more conclusive longitudinal studies.
In the meantime, this study gives one of the most prominent group of physicians something to wrap a stance around, in light of increasing attention that Congress and the public is paying to the issue. It also gives Congress some medical evidence to base their demands on. We expect growing attention to and action on bisphenol A. The ACC won't be able claim so dismissively that there are no human studies.
