Endocrine-Disrupting Chemicals FAQ

What makes endocrine-disrupting chemicals (EDCs) different from other chemicals that might put you at risk?

Chemicals are typically evaluated at various doses to determine a safe level of exposure. Below a certain level, a chemical that doesn’t have a toxic effect is considered safe.

Yet hormones naturally work at extremely low concentrations, and during certain times in a person’s development, even the smallest amount of a hormone when none would normally exist could potentially cause abnormal changes in the body.

This fact has consequences for how we should test the safety of potential EDCs. A new paradigm is needed to properly account for the large effects of small amounts of EDCs.

New data are dramatically improving our understanding of the causes of disease, the effects from low levels of exposures, and why certain people might be more susceptible to chemical effects (e.g., due to differences in age, health, or genetics). Also, each person is exposed to a different mixture of chemicals, including EDCs, which creates a unique exposure profile over a lifetime that further complicates definitive cause-and-effect findings.

If EDCs are all around and pose such a risk, why haven’t I heard about them before?

The term “endocrine disruptor” only came into common use in 1991 after a working session on chemically-induced alterations in sexual development as part of a Wingspread Conference. This was the first time a group of researchers reached a public consensus that endocrine-disrupting chemicals in the environment were disturbing reproductive health. Five years later, the book Our Stolen Future brought attention to the widespread ecological and human health consequences of EDCs.

These two events sparked a wave of research, and brought to light the high potential for risk to human health posed by EDC exposure.

Research has steadily progressed and exposed the harmful effects of EDCs such as lead, DDT, DES, and BPA. However, due to the unique complications of EDCs—the effects can take years to show, direct human experimentation is unethical, etc.—findings have taken a long time to progress.

But new tools and data types are facilitating, on an unprecedented scale, the testing and evaluation of chemicals that previously could not be evaluated. As researchers have shown, endocrine-disruption by chemicals has been the root of drastic effects on our environment for many decades, but it has only more recently that the term EDC came into use.

However, some stakeholders with financial interests in manufactured chemicals and pesticides have not always accepted the overwhelming global scientific consensus on EDCs. They have not entirely adopted the concerns of the American Medical Association or World Health Organization or the conclusions of gold-standard EDC science that abounds in peer-reviewed journals.

Even though the science is clear, some stakeholders are slow to change without regulatory measures that mandate protections for the public.

Why are so many EDCs still used in everyday products?

Chemicals contribute enormous good to the world—protecting us from illnesses and safety hazards, enabling untold conveniences, and adding to economic growth. Declaring that a chemical poses an unreasonable risk to human health and the environment is a very weighty decision. It has to be grounded in sound science.

For this reason, the process for banning or even restricting the manufacture or use of a chemical is an extremely thorough process. Multiple layers of review (and often multiple governmental agencies) are involved before any decision is made.

Finding the “smoking gun” linking a specific EDC to a specific disease is also difficult. Although data from cell-based studies, animal studies, and other experiments have produced a wealth of evidence to support connections in many cases, there are times when proving an EDC’s contribution to human disease would require exposing people to the EDC and observing the resulting disorder, which is unethical.

Mixtures are another challenge. Since people are exposed to a complex mixture of chemicals throughout their lives, it can be difficult to establish if health effects are caused by one, a few, or a broader mixture of the more than 85,000 man-made chemicals that are now in use. The timing of people’s exposure and the long-term persistence of many EDCs after exposure complicate matters further.

Despite all these challenges, some EDCs have been banned in many countries, and the data linking other EDCs or classes of EDCs to chronic disease is comparable in strength and breadth to the evidence that links tobacco smoking with lung cancer.

What can I do to protect myself and my family from EDCs?

You can seek out practical What You Can Do and learn about common EDCs and where they are found.

Beyond that, you can learn how to avoid some EDCs to reduce your exposure. For example, some products are labeled BPA-free and the market is developing some BPA-free alternatives for water bottles and plastic containers . . . with the caveat that some BPA substitutes show the same effects as BPA.

The more familiar you become with EDC regulations in the United States, European Union, and elsewhere, and the more you know about where a product and its components were manufactured, the more informed you’ll be in your purchasing decisions.

You can also help to keep EDCs out of the environment for the long-term by recycling. For instance, less than one third of plastic bottles in the United States are recycled, meaning that the rest—and their EDCs—end up in landfills or leaching into water supplies. Similarly, more careful recycling of electronic equipment and certain flame-retardant products can limit the amount of these potential EDCs that end up in the environment.

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For 100 years, the Endocrine Society has been at the forefront of hormone science and public health. Read about our history and how we continue to serve the endocrine community.