More Junk Science? The Anti-BPA Crusade is Back
The 25-year controversy involving BPA in food packaging won’t go away. It continues to hang ominously like a black cloud over the food industry.
Bisphenol A, more commonly known as BPA, is a chemical used primarily in the production of polycarbonate plastic and epoxy resins. The polycarbonate is used in food contact materials such as food containers and processing equipment. Epoxy resins are used in protective linings for a variety of canned foods and beverages, including infant formula.
Over the years Health Canada (HC) conducted periodic reviews of BPA to determine whether dietary exposure to it could pose a health risk to consumers. Based on the overall weight of evidence, including reaffirmation by other international regulatory agencies (notably the U.S., Europe and Japan), HC’s Food Directorate has concluded again unequivocally that the current dietary exposure to BPA through food packaging uses is not expected to pose a health risk to the general population, including newborns and infants. In response to growing consumer concern, HC hosted a huge expert meeting in November 2010 in collaboration with several national regulatory authorities and international bodies such as the World Health Organization (WHO) and the Food and Agricultural Organization of the United Nations (FAO) to review the current science. The clear conclusion of this expert meeting confirmed th at BPA was safe for food packaging. Moreover, HC has continued to do a number of studies, reports and surveys, all of which are posted online. HC has made a real effort to make the science available to the lay public and to try to interpret it in ways that the ordinary consumer can understand. HC’s study of BPA levels in canned drinks, for example, notes that a person would have to consume 940 canned drinks in one day to reach the tolerable daily intake.
Still, the issue is raging back in the media and the blogosphere This latest anti-BPA crusade seems to have arisen from the recent media re-discovery of BPA alarmist Dr. Frederick Vom Saal who has made it clear that in his opinion “there is no scientific argument… there is overwhelming evidence of harm.” France’s recent decision to ban the manufacture, import, export and marketing of all food containers containing BPA (effective in 2015) has added some scientific “credibility” to the anti-BPA movement.
The controversy among scientists has often been personal and bitter. Even highly respected Professor Richard Sharpe of the UK’s Medical Research Council was so angered by the bad science of the critics of PBA that he wrote an essay in 2009 in which he documented their consistent violation of the “fundamental principles of scientific inquiry.” Sharpe argued that the “scientific mess” around PBA was caused by “supposedly fellow scientists” who “literally play loose with the scientific evidence.” Not to be outdone, Vom Saal insists that all the scientific studies that have found BPA safe cannot be trusted because of an industry-funded conspiracy in the United States. For scientists, that’s serious name-calling.
Even if there is little health risk, governments are forced to waste scarce resources to respond to the perception of risk. According to Professor Sharpe “repetitive work on bisphenol A has sucked in tens, probably hundreds, of millions of dollars from government bodies and industry which…looks increasingly like an investment with a nil return.” My colleague at Carleton University’s Food Science and Nutrition Program, internationally recognized professor of chemistry David Miller, shares this concern: “The unsaid danger here is how much money and effort is being put on BPA instead of things that might have a larger health impact.”
The continuing BPA controversy highlights another important issue—the problems that scientific uncertainty pose for government regulators. Professor Sharpe thinks that the basic problem is that “politicians—people in decision-making positions—don’t understand uncertainty.” Maybe. In my experience, it is just as problematic that most scientists don’t understand the regulatory system. Integrating science-based risk assessment and policy-based risk management is diabolical in its complexity, yet one of the most important public policy challenges of our time.