Endocrine disruptors are chemicals that may interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife. A wide range of substances, both natural and man-made, are thought to cause endocrine disruption, including pharmaceuticals, dioxin and dioxin-like compounds, polychlorinated biphenyls, DDThttp://www.Merriam-webster.com and other pesticides, and plasticizersDictionary of Environmental Health such as bisphenol A. Endocrine disruptors may be found in many everyday products– including plastic bottles, metal food cans, detergents, flame retardants, food, toys, cosmetics, and pesticides. The NIEHS supports studies to determine whether exposure to endocrine disruptors may result in human health effects including lowered fertility and an increased incidence of endometriosishttp://www.Merriam-webster.com and some cancers. Research shows that endocrine disruptors may pose the greatest risk during prenatal and early postnatal development when organ and neural systems are forming.
How do endocrine disruptors work?
From animal studies, researchers have learned much about the mechanisms through which endocrine disruptors influence the endocrine system and alter hormonal functions.
Endocrine disruptors can:
- Mimic or partly mimic naturally occurring hormones in the body like estrogens (the female sex hormone), androgens (the male sex hormone), and thyroid hormones, potentially producing overstimulation.
- Bind to a receptor within a cell and block the endogenous hormone from binding. The normal signal then fails to occur and the body fails to respond properly. Examples of chemicals that block or antagonize hormones are anti-estrogens and anti-androgens.
- Interfere or block the way natural hormones or their receptors are made or controlled, for example, by altering their metabolism in the liver.
What are some examples of endocrine disruptors?
A wide and varied range of substances are thought to cause endocrine disruption.
Chemicals that are known endocrine disruptors include diethylstilbestrol (the synethetic estrogen DES), dioxin and dioxin-like compounds, polychlorinated biphenyls (PCBs), DDT, and some other pesticides.
Bisphenol A (BPA) is a chemical produced in large quantities for use primarily in the production of polycarbonate plastics and epoxy resins. The NTP Center for the Evaluation of Risks to Human Reproduction completed a review of BPA in September 2008. The NTP expressed “some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A."
Di(2-ethylhexyl) phthalate (DEHP) is a high production volume chemical used in the manufacture of a wide variety of consumer food packaging, some children’s products, and some polyvinyl chloride (PVC) medical devices. In 2006, the NTP found that DEHP may pose a risk to human development, especially critically ill male infants.
Phytoestrogens are naturally occurring substances in plants that have hormone-like activity. Examples of phytoestrogens are genistein and daidzein, which can be found in soy-derived products.
- Papers of note — cadmium, phthalates, and PAHs
- E.hormone: Hormones and the Environment
- Investigating medications as a source of phthalate exposure
- NIEHS-funded scientists say more chemicals linked to neurodevelopmental disorders
- Scientists begin to fill in the gaps in understanding about fracking
- 3-D images show flame retardants can mimic estrogens
- Zebrafish developmental assays test the safety of new chemicals
- Consuming Canned Soup Linked to Higher BPA Levels
- Bisphenol A (BPA) Information for Parents
- E.hormone: Hormones and the Environment - A gateway to events, research, news, books and learning facts sheets on the impact of environmental estrogens and other hormones on human health.
- Endocrine Disruptors Research Initiative - An inventory of federal government research on the effects of environmental chemicals on the endocrine system of humans and wildlife. Includes links to other related sites.
- Endocrine Disruptors(1004KB)
- Endocrine Research Resources(966KB)
- FDA - Bisphenol A (BPA)
- Household Products Database: Bisphenol A-epichlorohydrin copolymer acrylate
- Household Products Database: Bisphenol A, epichlorohydrin polymer
- Household Products Database: Bisphenol A, epichlorohydrin polymer, tall oil fatty acids ester
- Household Products Database: Bisphenol A, formaldehyde, epichlorohydrin polymer
- Linking Early Environmental Exposures to Adult Diseases(312KB)
- Research Links - Scientific Resources - Environmental Health - Endocrine Disruptors
- Soy Infant Formula
- Talking Glossary of Genetic Terms: Organ
- WHO Report: State of the science of endocrine disrupting chemicals - 2012
- EHP Student Edition Lesson: Are EDCs Blurring Issues of Gender?(324KB)
- EHP Student Edition Lesson: Arsenic: An Element of Suffering(121KB)
- EHP Student Edition Lesson: Beauty or the Beast?(154KB)
- EHP Student Edition Lesson: Bisphenol A and Diabetes(196KB)
- EHP Student Edition Lesson: Consider the Source(1MB)
- EHP Student Edition Lesson: Lettuce Explore Perchlorate in Food(90KB)
- EHP Student Edition Lesson: Soy: Filling in the Gaps(146KB)
- EHP Student Edition Lesson: Wildlife Study Comparison(139KB)
- Green Chemistry - this resource includes video, produced by WGBH (Boston), that talks about a national study looking at dust samples in homes. Phthalates, BPA, and brominated flame retardants are discussed, as is, the possibility of safer alternatives using green chemistry. Discussion questions are included.