Endocrine disrupting chemicals (EDCs) have become an increasingly popular topic in the science world as of late. Dr. Shanna Swan’s recently released book, Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race, sheds light on the health impacts of EDCs.
In addition to Dr. Swan’s book, new studies and growing global movements to divest from fossil fuel production have shone a spotlight on the negative health impacts of EDCs.
What is the Endocrine System?
Graphic courtesy of the United States Environmental Protection Agency
Endocrine systems exist in all mammals, birds, fish, and other types of living organisms, and consist of glands located throughout the body. In humans, these glands exist in the brain and throat regions, as well as in the pancreas, in both male and female reproductive organs, and more. These glands create the hormones — chemical messengers — that regulate our biological processes from our conception and fetal development, through adulthood, and into old age. Some of these processes include the development of the brain and nervous systems, the growth and function of reproductive systems, and the maintenance of metabolisms and blood sugar levels. The endocrine system also plays a critical role in helping us respond appropriately to stress and maintain healthy brain function, such as experiencing and regulating emotions, learning, and remembering.
What are EDCs?
An EDC is a chemical or chemical mixture that interferes with hormones and the endocrine system and produces unfavorable health effects in laboratory animals, wildlife, livestock, pets, and humans. Specific types of EDCs occur naturally, while others can be synthetically produced.
One type of an EDC is bisphenol A, commonly known as BPA, which is a chemical used to make types of plastic and resin. BPA can be found in food storage containers, water bottles, and more, and has been associated with male sexual dysfunction.
How do EDCs Impact Health?
Graphic courtesy of Health and Environmental Alliance
and the Endocrine Disruption Exchange
There are two primary ways in which EDCs can impact health. Some EDCs mimic or block hormones. An EDC that mimics a hormone can cause the body to over-respond to a specific stimulus. Examples of this could include a growth hormone that results in increased muscle mass or the production of insulin when insulin isn’t needed.
The second way in which EDCs can impact health is by changing the amount of hormone available by altering the production, metabolism, or secretion of that hormone. EDCs may stimulate or inhibit the endocrine system, causing overproduction or underproduction of hormones, such as with an overactive thyroid condition.
But what does this mean?
EDCs can negatively impact health at any age, but exposures during fetal development, early childhood, and puberty can be particularly detrimental. Recognized health effects of EDCs exposure across all ages include:
Abnormal development of sex organs
Reduced ability to have children
Cancers such as breast, ovarian, prostate, testicular
Impaired intellectual development
Altered behavior or response to stress
Increased buildup of fat
Changes in ability to respond to insulin and regular blood sugar
EDCs and Shale Gas Development
EDCs have also been identified in fracturing fluid and in the wastewater and air emissions produced during the process of shale gas development. People and animals living near shale gas facilities may be exposed to EDCs through inhalation, ingestion, and skin absorption.
In fact, a recent study shows that unconventional oil and gas development chemicals and wastewater disrupted hormone receptors — special proteins in cells that receive messages from substances in the bloodstream and direct cell actions — ultimately altering sperm counts, ovarian function, and pituitary hormones in adulthood, as well as inducing mammary gland changes and precancerous lesions.
Another study compared existing studies to generate a list of 106 chemicals associated with shale gas activity. Of these 106 chemicals, 22 of them have been shown to disrupt endocrine activity and potentially impact hormone production. The authors of the study noted that, even at low levels of exposure, EDCs can negatively affect health.
Learn More
Learn more about endocrine disrupting chemicals and shale gas development by viewing our latest webinar.
In this webinar, hosted by EHP and Halt the Harm Network, Dr. Chris Kassotis of Wayne State University presented “From Fracking to Fat Cells: How Unconventional Oil and Gas Production May Influence Metabolic Health.” Joining Dr. Kassotis was Dr. Laura N. Vandenberg of the University of Massachusetts at Amherst. Dr. Vandenberg presented “A Poisoned Web: from Unconventional Oil and Gas Production to Plastics to Endocrine Disruptors.” Dr. Ned Ketyer, EHP’s medical advisor, moderated the event.
Additional Resources • Plastics, EDCs, and Health: A Guide for Public Interest Organizations and Policy-Makers on Endocrine Disrupting Chemicals and Plastics • Developmental Exposure to a Mixture of Unconventional Oil and Gas Chemicals: A Review of Experimental Effects on Adult Health, Behavior, and Disease