Discussion: (0 comments)
There are no comments available.
View related content: Health Care
Scientific institutions around the world reject bans on BPA. So why are politicians imposing them?
Scientific institutions around the world reject bans on BPA. So why are politicians imposing them?
Well-meaning laws sometimes backfire. That’s especially true when they are passed in reaction to media frenzies driven by ideology rather than science. And that’s what’s happening in the United States and Europe, where advocacy groups are raising new alarms about bisphenol A (aka BPA), a controversial plastic used in myriad products, including plastic containers and dental sealants, and in epoxy linings in canned goods to prevent spoilage.
On Tuesday, the California State Senate approved a ban on baby bottles and sippy cups that contain BPA, with the measure now going to the Assembly for a final vote. Set to take effect next July, the ban was approved despite the fact that no governmental science-based advisory board in the world has concluded that BPA is harmful.
But political systems often operate with limited information and short time horizons, while much of science is complex and evolving. Bowing to relentless campaigns, restrictions on BPA used in baby bottles have been imposed politically in 11 states and in a few countries, such as France and Canada.
In a sidestep around the science, activists are aggressively turning up the heat on legislators around the world. The latest uproar involves the presence of miniscule amounts of BPA on thermal paper receipts printed at supermarkets or ATMs, and on the money that comes in contact with them. The brouhaha has touched off a swirl of recent media coverage, much of it just plain wrong.
Thermal paper has a chemical coating, usually made in part with BPA, which colors when heated during the development process. Greenpeace Germany just released an analysis of receipts collected from eight European supermarket chains—that’s right, just eight. There was not even a façade of scientific controls. Seven had traces of BPA or a related chemical, bisphenol S (BPS). The European press exploded with stories of the alleged harm faced by consumers, and a prominent French legislator called on stores to abandon paper containing either chemical, or face a legislative ban.
Political systems often operate with limited information and short time horizons, while much of science is complex and evolving.
Greenpeace was copying a media stunt run last year by the Washington-based Environmental Working Group, which co-sponsored the California legislation. EWG tested 36 registers from around the United States, finding BPA on 29 of them. There was no pretense that this was a scientific study, but the survey generated more than a thousand news stories. That’s because conventional wisdom among many journalists is that BPA should be banned. Just last week, the Portland Oregonian declared, “BPA represents a health risk,” trashed “industry lobbyists” for scuttling a state bill that would have partially banned the chemical, and called for new restrictions.
In June, Connecticut became the first governmental body to ban thermal paper containing BPA. The ban is set to take effect in two years, assuming the Environmental Protection Agency identifies a safe, commercially available alternative, or in four years even if it doesn’t.
Are these votes based on good science? Why are politicians imposing bans on BPA, when regulators and scientific institutions around the world have carefully reviewed the entire body of evidence about the chemical and have opposed calls for bans?
Endocrine disruption brouhaha
Anti-ban campaigners often cite two well-known but often misunderstood facts: toxics sometimes pose dangers to pregnant women and newborns and BPA shows up in the urine of more than 90 percent of adults and children. How do these two facts fit together? Are prospective mothers and infants exposed to dangerous levels of BPA, as many media reports reflexively suggest? What does the weight of evidence show about the effects of BPA?
We know that BPA has an estrogenic effect and may subtly impact endocrine function. But so do a variety of foods, such as tofu and many nuts, to no ill effect. To put this in context, BPA is less potent than the naturally occurring estrogens in these foods and 10,000 to 100,000 times less potent than the synthetic estrogen in birth control pills.
The critical concern is whether BPA gets into our system in its bioactive form at a level that would have anything beyond a mild impact. As of 2008, the scientific jury was out on that question. Some environmental groups had heatedly contended that studies on BPA which indicated little or no effect were not even worth considering if industry was linked to the research in any way. They argued that the only reliable studies were those done at universities or by government scientists.
Over the past decade, a string of small-scale studies, widely promoted by chemophobic advocacy groups, has led to a popular but not a scientific consensus that BPA may be harmful.
It’s prudent to be aware of potential conflicts of interest when evaluating studies, but anti-BPA campaigners have created a strawman in the way they portray the research landscape. There have been thousands of studies on BPA, most of which are called “exploratory” research done primarily at universities. Many consist of laboratory animals exposed to BPA by injection (more sophisticated studies administer BPA orally to more accurately mimic how humans are exposed) at doses hundreds or thousands of times higher than what humans face. In many of these smaller-scale studies, animals have suffered developmental abnormalities. In contrast, the most comprehensive studies—many funded by industry, but by no means all—have shown little or no effects.
Over the past two years, in an attempt to close the knowledge and controversy gap, five prominent international regulators or toxicology organizations reviewed thousands of BPA studies—government, university, and industry.
• In January 2010, the U.S. Food and Drug Administration, relying on extensive data from the National Toxicology Program, rejected tighter restrictions on BPA, raised questions about the contradictory findings in “novel” small-scale studies, stated BPA “is not proven to harm children or adults,” and reaffirmed that the most reliable studies to date support “the safety of current low levels of human exposure to BPA.”
• In September 2010, the 21-member European Food Safety Authority (EFSA) science panel reviewed 800 studies over three years and rejected a ban or a lowering of threshold exposure limits, concluding in particular that the data did not support claims that BPA induced neurotoxic effects.
• In November 2010, the World Health Organization expert review panel on BPA said it would be “premature” to regulate or ban the chemical.
• In April 2011, an evaluation of thousands of BPA studies by the German Society of Toxicology concluded, “The available evidence indicates that BPA exposure represents no noteworthy risk to the health of the human population, including newborns and babies.”
• In July 2011, two Japanese oversight agencies combined to produce an extensive update of BPA policy, responding to what they wrote is “a tremendous amount of new information on BPA with regard to human health.” Their conclusion: no reproductive toxic effects; no carcinogenicity; no concern for skin contact; and no evidence of adverse neurotoxic effects. “The risk of BPA with regards to human health was believed to be very small.”
What’s more, U.S. regulators under President Obama have moved aggressively to fund researchers at several government laboratories to address the frequently heard complaint that the more robust studies are “tainted” by industry connections. Their findings:
• No developmental neurobehavioral effects from BPA
The National Toxicology Program had expressed concern about the possible neurological impact of BPA, which had shown up in some small-scale rodent studies. Two well-designed studies done at separate EPA and FDA labs found no evidence for neurobehavioral effects from exposure to BPA.
• No developmental effects of BPA on male reproductive organs
Some small studies, but not others, have suggested that BPA might impair the development of the reproductive organs of rats. In a comprehensive study, the EPA tested this thesis, using a potent estrogen as a baseline comparison. No effects were found from BPA exposure, although the estrogen did result in adverse effects.
• BPA is efficiently metabolized and rapidly eliminated, making it unlikely to cause health effects
There was no pretense that this was a scientific study, but the survey generated more than a thousand news stories.
It is important to determine whether BPA is bioactive in humans or relatively harmless (as the CDC has reported). A series of studies on monkeys and rats found it is efficiently metabolized not only in adults, but also in pregnant animals, newborns, and the fetus. The mother processes bioactive BPA, rendering it harmless. What about in humans? In June, scientists from the FDA, Centers for Disease Control, and the Pacific Northwest National Laboratory published a study that had tracked the blood and urine of volunteers who ate lots of canned food over a 24-hour period, which exposed them to high amounts of BPA. The result according to lead author Justin Teeguarden:
“Blood concentrations of the bioactive form of BPA throughout the day are below our ability to detect them, and orders of magnitude lower than those causing effects in rodents exposed to BPA. For me, the simple takeaway is that if blood concentrations of bioactive BPA are much lower than those in this sensitive animal model, effects in the general human population seem unlikely at best.”
• Fetus is not significantly exposed to bioactive BPA after oral exposure to mother
Almost all the concern about BPA’s effects has been generated by studies of developing animals or in maternal and fetal fluids and tissues. The research so far has been contradictory and difficult to interpret. To address flaws in prior research, a team with the National Center for Toxicological Research released a study in July concluding that the fetus is not significantly exposed to unmetabolized BPA after oral exposure to the mother.
In sum, over the past decade, a string of small-scale studies, widely promoted by chemophobic advocacy groups, has led to a popular but not a scientific consensus that BPA may be harmful. Now, independent scientists carefully examining that thesis are finding it wanting. The latest research suggests BPA is unlikely to cause adverse health effects because the body efficiently metabolizes and eliminates it. Yet, remarkably, none of these studies—state-of-the-art independent and government-conducted—has received anything more than token notice.
The dearth of popular articles reporting on the latest trends in BPA studies has established an unvirtuous cycle. Because most opinion and health writers rely more on Google than on science papers when writing their stories, they end up regurgitating outdated and increasingly alarmist conclusions, hardening ideological lines. That brings us to the hysteria du jour, thermal paper.
BPA is less potent than the naturally occurring estrogens in these foods and 10,000 to 100,000 times less potent than the synthetic estrogen in birth control pills.
As the scientific consensus on BPA’s endocrine effects has shifted from amber to a cautious green, advocacy groups are turning away from the science toward populist campaigns. Thermal paper receipts are the latest battleground. Consider a recent report by the Environmental Health News (EHN), which was founded by one of the progenitors of the now questionable “endocrine disruptor” thesis. “Money is Dirty” highlighted a new study that found BPA transferred from paper receipts in wallets to currency and often showed “considerably high amounts.” That grossly misstates what authors Chunyang Liao and Kurunthachalam Kannan conclude. “The estimated daily intake of BPA through dermal absorption from handling paper currencies was on the order of a few nanograms per day,” they wrote—an amount that “appears to be minor.” Rather than a cause for alarm, as EHN presents it, this study demonstrates that even when the “worst case” exposure is taken into account, BPA exposures from money are still 140-thousand-fold lower than doses considered safe by worldwide regulatory authorities.
EHN also referenced a 2010 study by Sandra Biedermann and colleagues claiming, “up to 27 percent [of BPA found on humans who handle thermal paper] can be transported to the bloodstream within two hours of dermal exposure.” That’s inaccurate. Biedermann actually concluded, “The experiments did not enable us to determine whether or not BPA passes through the skin into the human metabolism.” The estimated exposure was miniscule even for store clerks handling receipts all day—42 times lower than the exposure dose considered potentially harmful—a level which itself has a built-in safety buffer of at least 100 times.
While scientists believe the presence of BPA on thermal paper or paper money is a non-issue, from the media we get groupthink and the reckless use of words like “tainted.” A web search couldn’t find one article citing last year’s influential World Health Organization panel, which pointedly concluded that BPA found in receipts was of “minor relevance.” Nor was there mention of the thermal paper study released in June by the precaution-obsessed Danish Environmental Protection Agency. It concluded, “Risk assessment shows … receipts do not pose a risk to consumers or cashiers who handle the receipts.”
So what’s the big deal, you might ask? Why not placate public opinion and just switch from BPA-based paper even if there is no evidence it causes harm? There has already been a move away from BPA-based thermal receipts. Consumer-focused companies care more about what customers feel than what scientists know. In May, Kroger, the nation’s largest grocery chain, announced it would get rid of BPA in register tapes by the end of this year. Whole Foods and Yum! Brands, owner of KFC, Pizza Hut, and Taco Bell, followed suit. But for shoppers, the operating headline might be “naïve consumer beware.”
Appleton Papers, the nation’s largest thermal paper maker, has removed BPA from its products, but is instead using diphenyl sulfone, which is the chemical name for BPS. It claims: “There is little evidence that diphenyl sulfone [BPS] poses risks to human health.” But BPS has a very similar chemical structure to BPA. The company can’t have it both ways, alleging that BPA is harmful while the mildly estrogenic BPS used in its paper is totally safe.
BPS is one of 18 chemicals for use in thermal paper that the EPA is evaluating. Like other alternatives, its only real virtue at this point is that it has been less tested than BPA. That doesn’t mean it’s safer. BPA is readily biodegradable, which is important because chemicals in register paper end up in the recycle stream, in effluents. Bacteria naturally degrade traces released to the environment. BPS, on the other hand, is not readily biodegradable. Once paper with BPS gets to a recycling plant, it may be difficult to remove in the wastewater treatment system and more likely to be emitted.
Businesses that adopt an alternative are replacing an inexpensive, well-tested substance that has limited but identifiable risk (BPA) with a more expensive and untested chemical that has other yet unidentified health and environmental impacts.
Appleton also boasts that the “EPA … has identified bisphenol sulfone as a potentially acceptable substitute for BPA.” Well, no. The EPA rejects claims that substitute chemicals are safer than BPA, which it has not determined is unsafe. “We have no opinion on the alternatives we’ve identified,” said Cal Baier-Anderson of the EPA. Its recommendations are expected next year. “It’s unlikely that EPA is going to come out with the list of preferred chemicals,” she said, because hazard assessments like this one usually identify nothing more than a list of tradeoffs. “One alternative may not be a reproductive toxicant but it may be an acute aquatic toxicant.”
This is a classic case of unintended consequences. Businesses that adopt an alternative are replacing an inexpensive, well-tested substance that has limited but identifiable risk (BPA) with a more expensive and untested chemical that has other, yet unidentified, health and environmental impacts. They are throwing the toxic dice in order to appear green and avoid controversy. This is not a scientific-based response to consumer safety concerns but short-term thinking—cynical tactics in reaction to simplistic advocacy campaigns buttressed by lemming reporters.
But the science catches up in the end. There are no silver bullets in toxicology. Every chemical, including natural ones, has effects. More than likely, the EPA will not endorse an alternative, but it will simply allow each manufacturer to select a less-than-perfect printing solution.
There are lessons for the media and policy makers: (1) Journalists need to do their science homework and not remain vested in any one conclusion, no matter how ideologically attractive, and they must have the backbone to follow evolving evidence even if it leads to conclusions that contradict earlier reporting; and (2) Science, not Google postings, should drive legislation.
At its best, evidence-based science offers the opportunity to make sober regulatory decisions. At this stage in our scientific understanding, the various bans of BPA will cause more harm than good. Before a regulation is passed, it should undergo a cost-benefit evaluation to assess unintended consequences. That won’t prevent unforeseeable problems, but sometimes the wisest course of action is to do nothing.
Jon Entine is a visiting fellow at AEI and senior fellow at the Center for Health and Risk Communication at George Mason University and STATS.
Image by Rob Green | Bergman Group
There are no comments available.
1150 17th Street, N.W. Washington, D.C. 20036
© 2014 American Enterprise Institute for Public Policy Research