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Welcome to PSR's Environmental Health Policy Institute, where we ask questions -- then we ask the experts to answer them. Join us as physicians, health professionals, and environmental health experts share their ideas, inspiration, and analysis about toxic chemicals and environmental health policy.


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Endocrine Disruption, Public Health, and National and International Security

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By Theo Colborn, PhD

This essay is in response to: What emerging environmental hazard should be next on the policy agenda?

From a national and international security perspective endocrine disruption should be right at the top of our list of concerns. Wait a minute, you ask, what is endocrine disruption? Well, endocrine disruption is the insidious trespass of man-made chemicals into every vital organ system in your body that comprises or is controlled by the endocrine system, such as the thyroid and parathyroid, pancreas, adrenals, thymus, male and female reproductive organs, the heart, digestive system, and skeletal system -- all the systems that participated in how you were constructed in the womb and how you are functioning today. Animals, including humans, have evolved along with many natural chemicals that can interfere with the endocrine system, but it has only been since the mid-1950s, when vast volumes and numbers of new synthetic chemicals derived from fossil fuels were introduced into commerce, that widespread disruption of the endocrine system has emerged as an international public health issue.

Modern toxicology dates back to the 18th century, but it was not until the 1950s that the “postmodern period of toxicology” burgeoned, concurrent with the release of many man-made chemicals after WWII. As a result, this new toxicology grew under the guidance of those making the chemicals and those using them in their products. The stated goal was to determine at what concentration a chemical could be released into the environment before it caused harm. But in the late 1970s and early 1980s it became obvious that something had gone disturbingly wrong. Wildlife, laboratory animal, and human epidemiological studies were linking a series of adverse health effects with specific chemicals or classes of chemicals, effects on the endocrine system that had been missed by the traditional toxicological protocols developed to determine the safety of chemicals. Disorders of the endocrine system, now at epidemic proportions, include learning disabilities and behavioral and mood problems, infertility, abnormal gonad development, cancers of the reproductive organs, unusual pubertal onset, diabetes, obesity, allergic and asthma reactions, and more.

In the past few decades, scientists with impeccable credentials have come from outside the discipline of toxicology using entirely new protocols to test chemicals for their safety. Based on the principles of developmental endocrinology, starting with exposures in the womb and taking a disease-based (not chemical-based) approach, they have linked widely dispersed chemicals with many disorders that are currently burdening society and governments with inestimable costs for diagnosis, treatment, alleviation, and life-long care. A plethora of peer reviewed studies tracking chemical exposure prior to conception throughout life, using assays designed to detect subtle molecular and cellular effects, confirm the complexity and sensitivity of the endocrine system.

Unfortunately, legislation is lagging behind science, and currently only the crude reproductive and developmental effects detected in traditional toxicological assays are acknowledged by governments. The present approach of regulating chemicals under the short-sighted guise of using reproduction and grossly observable birth defects as a substitute for endocrine disruption is failing to protect human and ecological health. It is time for governments to protect the global activity of all the endocrine subsystems as one. Just as the term “cancer” has become the catchall for all the different kinds of cancer, involving numerous organs and tissues, and differing in their intensity and ability to metastasize, the term “endocrine disruption” must be accepted for its ultimate damage to the structure and function of the entire endocrine system. No new standards and regulations designed to protect human health should leave out endocrine disruption, including all the downstream alterations in the multiple subsystems of the endocrine system.

The wealth of 21st century peer-reviewed literature, combined with the latest public health statistics, demonstrates that a myopic strategy will lead only to greater dysfunction at the population level. Fewer and fewer people will be healthy and intelligent enough to provide the leadership society needs to work toward world peace. Fossil-fuel derived chemicals are depriving humanity of its integrity and the fate of the human race should no longer be put at risk because current toxicological testing has failed to detect damage from chemical exposure that does not fall under the current antiquated regulatory rubric. From an economic and national security perspective the costs are too high to delay any longer.


David Thanhauser MD said ..

I have been researching this realm and I am very concerned. We just found that most male small mouth bass -even in down east Maine wildlife refuges, have been found to be inter-sex: they have eggs in their testes. Is there anyone out there doing systematic, persistent research on a variety of endocrine disruptors in model animal systems? It is needed!

February 5, 2017 said ..

Can someone help me.I have forteo induced hypothyroidism. T3 T4 Tsh ok doctor ignore all my symptoms. I've gotten huge in a few months.have scoliosis.a giordano .

April 13, 2015
Dr. William Iwen said ..

Dr.Colborn is highlighting and bringing attention to what will prove to be the most devastating long term impact on all species and their reproductive success. Many thanks to Dr. Colborn's inspired and most meaningful research. All health professionals who heed her message will pave the way to the future.

August 24, 2013
edgar said ..


April 17, 2013
Vidya Teeluck said ..

Quite informative in presenting a contrast report of the many ills of the 21st century and the effects it possess to mankind.The information contributed in adding to my knowledge.

October 24, 2011
Richard Weiskopf said ..

Very informative. It does outline the magnitude of the task.

November 5, 2010
Daniel Kerlinsky MD said ..

Ask a firefighter or the child of an Agent Orange exposed Vietnam Veteran about their reproductive health. Increased sex drive, decreased sex drive, testicular cancer -- when we recognize the patients in our offices impacted by toxic chemicals, one at a time, we will be able to have more impact on our colleagues and public policy.

November 4, 2010

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