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Unenlightened “How Chemicals Affect Us” gets a D+ in endocrine disruption

Twenty years of scientific literature on “endocrine disruptors” cannot be drummed up in 790 words, but consumers’ fear of them can (“How Chemicals Affect Us,” May 2, 2012).

A good writer, but not a science reporter, New York Times columnist Nicholas Kristof, before all else, failed even to define “endocrine disruptor.” This is important because the term is one of the most widely misused to describe the phenomenon the reporter makes a poor attempt to explain.

The Institute of Population Health at the University of Ottawa – in Canada, a country whose regulatory approach Kristof favors – breaks the issue down quite well:

The term endocrine disruptor is widely used at present by representatives from the media, regulatory groups, academic scientists, and non-governmental organizations to communicate divergent meanings. The net result is significant confusion surrounding the messages that are being communicated concerning the potential for chemicals to interact with physiological systems and to induce endocrine toxicity.

It is not simply a matter of “wreak[ing] havoc with the endocrine system that governs hormones,” as Kristof reduces it, and overstates it. It is much more nuanced and scientifically complex.

More accurately put, an endocrine disruptor is “an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny, or (sub)populations.” And that’s according to the World Health Organization’s (WHO) International Programme on Chemical Safety.

Furthermore, the NYT article gives the impression that the science behind endocrine disruption is a new development. It isn’t. The phenomenon has received years of thoughtful attention from independent panels of scientists and government regulatory bodies.

And in contrast to Kristof’s assertion, the U.S. EPA – not its European or Canadian counterparts – has taken the lead to develop a testing program to determine, for a fact, whether a substance interacts with the endocrine system and causes an adverse effect through an endocrine mechanism. That program is underway today.

It is unfortunate that Kristoff has decided to uncritically accept the alarms of some in the scientific community, and to amplify them through his own uninformed endorsement, without first asking whether there is broad scientific consensus in support of these claims. If Kristof had dug a bit deeper, he would have discovered that there is not.

The fact is that changes to the endocrine system are happening all the time. It’s called “endocrine modulation.” It occurs while you sleep, when you eat, and while you exercise. It reacts to stress. It works to regulate various levels of nutrients and hormones circulating through your body.

Modulation is required for all these essential bodily functions. But based on the non-scientific definition Kristof gives us, even these healthy functions would qualify as “endocrine disruption.” The University of Ottawa explains:

For example, consuming food causes changes in numerous hormones involved in digestion and metabolism. It is also recognized that bright light will alter hormone levels in the brain affecting human behavior and depression. Thus, even foods and light could be considered as endocrine disruptors since they do induce functional changes in hormone levels.

Why does endocrine modulation matter to discussions of endocrine disruption? Because some well-known assessments of endocrine disruption do not differentiate between “disruption” and “modulation.” In other words, what they are calling disruption could very well be a natural, healthy, essential modulation of our endocrine systems in response to our environment.

Journalism of this caliber and reach does not serve the public if it ignores the tough questions that science is debating, and opts instead to repeat claims whose only impact is to spread fear and worry, not understanding.

Dr. Becker is a board-certified toxicologist and senior director of ACC Regulatory & Technical Affairs division.

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