Critics point out that some chemicals like bisphenol A can briefly influence human endocrine levels. But they dismiss the fact that our endocrine systems are dynamic and built to quickly adjust to brief exposure to these endocrine disruptors, writes Jeff Stier.
Jeff Stier is a senior fellow at the National Center for Public Policy Research in Washington, DC and heads its Risk Analysis Division.
When it comes to food safety, the European Union and the United States have some of the most effective scientific and regulatory programs in the world.
So it came as a surprise when France flouted the studies and assurances of EU and US food safety regulators and sought to ban the use of Bisphenol A (BPA) in any food contact item starting in 2015.
Activists are trying to push the European Food Safety Authority (EFSA) in the same direction. The EU should hold firm to the science and policy-making that led it to find that BPA, at levels at which humans are exposed, does not present a danger.
The science supporting the safety of BPA has become stronger as government bodies have poured tens of millions of dollars into independent research.
The widely used chemical is an important component in, among other things, food containers such as cans, where its application prevents botulism.
You’ve probably heard of BPA, since every time another animal study comes out, it gets disproportionately wide play in the press.
A Google search for “BPA causes” leads to related popular search results including “BPA causes infertility”, “BPA causes homosexuality”, and “BPA causes obesity”. This is all nonsense. But that’s what happens when animal studies that bear no relevance to real world human exposures are rewarded with press, prestige, and promises of more research funding.
The possibility that anti-chemical activists could succeed in removing such a well-tested and important chemical from the marketplace has some scientists uncharacteristically outspoken.
A group of prominent science journal editors with a broad range of backgrounds and experience wrote a powerful piece in the journal Food and Chemical Toxicology this summer, which detailed why the BPA scare is scientifically unfounded.
They concluded that: “Regulations that profoundly affect human activities, that legally impose significant fines and even detention, should not be based on irrelevant tests forced to be regarded as relevant by administrative dictates, and on arbitrary default assumptions of no thresholds. Such standards would be contrary not only to science, but to the very principles of an enlightened governance and social contract. Not only scientists but society itself would pay dearly if unscientific approaches were to undermine our everyday practice of science, and the stringency of data analysis and evaluation developed by scientific thinking over the past centuries.”
The EFSA, the US Food and Drug Administration, and other governmental bodies have all pointed out that high dose animals studies are of little relevance to humans given our relatively low exposure.
So activists have fallen back on an old but still unproven theory that argues that very low levels of exposure actually have an even larger effect than higher exposures. But more and more research fails to support the allegations. In the US alone, the federal government handed out $30 million in economic stimulus money to study BPA. And even with that, the low dose theory still hasn’t been shown to exist in the real world.
Critics point out that some chemicals like BPA, known as endocrine disruptors, can briefly influence endocrine levels. But they dismiss the fact that our endocrine systems are dynamic, built to quickly adjust to brief exposure to endocrine disruptors, many of which occur naturally, in products like soy, and that our bodies metabolise BPA very quickly so that any minor change from such low exposure is transient, causing no harm.
Those seeking a ban have little to hang their hat on. The argument comes down to, first of all that endocrine disruptors are bad because they have a measurable effect on the human body, even though that effect isn’t shown to be harmful in humans. Secondly, that animals exposed to very high doses of endocrine disruptors do suffer harmful effects.
Thirdly, a regulatory scheme based on those justifications would amount to a de-facto ban on any product containing any amount of an endocrine disrupting chemical, since it is impossible to (ethically) prove, to the activists’ satisfaction, that the chemical is safe to humans.
That would be “ludicrous,” according to Daniel Dietrich, head of environmental toxicology research at Germany’s University of Konstanz. Dietrich, editor-in-chief of chemico-biological interactions, told the journal Nature, that he is among a group of respected scientists that rejects the “no threshold” theory that says absolutely no level of exposure is safe.
Instead, he argues regulators should rely on the “weight of the evidence,” which points clearly in the direction of a linear relationship between dose and response.
Regulators in the US, the EU, and other regulatory bodies have, to their credit, stuck with the weight of the evidence approach. Given the overwhelming evidence pointing to the safety of BPA at levels at which we are exposed, rational policy-making and sound science dictate regulators throughout the EU hold firm against the anti-BPA campaigns.