Closing in on the chemicals that make us fat or infertile
Mounting evidence suggests that chemicals in our environment contribute to obesity and diabetes, to reduction in male sperm counts and quality, and gender changes in frogs and fish, and many more adverse health effects.
But 15 years have passed already since the World Health Organization issued a report highlighting the state of the science on endocrine disruptors and recommending action to close the gaps of scientific knowledge on the question of how these potentially dangerous chemicals affect health and the environment. Since then, the squabbles over how to define an endocrine disruptor and how to evaluate the risks have largely prevented regulators from taking action.
The U.S. EPA seemed to take an early lead on addressing the issue. Although they started their program later than regulatory deadlines required, by 2009 EPA had orders out to companies that market a list of suspected endocrine disrupting chemicals, requiring them to further study the hormone disrupting potential of their chemicals and submit the information to the agency for consideration.
Sadly, the EPA's 2018 budget (pdf) eliminates all funding for risk review and prevention specific to endocrine disruptors and eliminates the endocrine disruptors program entirely. Although the plan indicates the "program can be absorbed into the pesticides program", the elimination of the budget supporting 8.9 full-time employees dedicated to the specialist topic ensures that progress will return to the slow track.
So hope turns to the European Union. After years of confusion and court orders sending the agency back to the drawing board, the European parliament has rejected the European Chemicals Agency (ECHA) definition of endocrine disruptors. The move recognizes that the ECHA has overreached its authority by writing certain risk-based exemptions into the definition.
This runs contrary to how other chemical hazards are defined: take carcinogens for example. A chemical is classified as known to cause cancer in humans (based on evidence in human populations), or presumed to cause cancer in humans (based on strong animal or computer-model evidence with additional information such as studies indicating the effect is likely due to similarities in human biology), or as a suspected human carcinogen (if some evidence exists but it is not sufficient to qualify as a known or presumed carcinogen). Note that there is nothing in these definitions that requires to show that the substance causing cancer in lab tests needs to be shown to cause cancer in the real world - that is a much harder thing to prove due to the wide variety of confounding factors in studies of widespread exposures to chemicals.
It is important to classify chemicals based on their hazards so that the potential for adverse effects can then be fully communicated in the first step. Only in the second step should the risks be evaluated - either by the consumer choosing not to buy the product containing the hazardous chemical or by the regulators, who will evaluate risks as well as benefits before deciding on the most appropriate policy for public protection.
If a definition can be agreed, then endocrine disruption hazards will be added to the EU's ambitious chemical control program, which may be our best hope to finally see progress addressing what appear to be one of the last great barriers to achieving consumer trust in chemicals and reducing unnecessary risks.