The ABCs of EDCs: The Explanation to Our Most Pervasive Medical Mysteries?

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The ABCs of EDCs: The Explanation to Our Most Pervasive Medical Mysteries?

Guest Blogger

Tuesday, September 22, 2009

JESSICA WEBB: The endocrine system is responsible for the secretion of hormones throughout the body. Hormones are transmitted throughout the body via blood vessels, sending messages and instructions that jumpstart a lifetime of vital developmental changes and processes (think of hormones as the Paul Revere of the endocrine system). From the time of conception, the regulation of hormones is pivotal for a healthy metabolism, normal growth and development, the onset of puberty, tissue function and even mood and psychological states. One can only imagine that the disturbance of such instrumental chemicals can be quite harmful to human development.

EDCs are synthetic substances that mimic naturally produced hormones and distort regulation in the endocrine system. All vertebrates, including humans, are fundamentally similar during the earliest stages of embryonic development. As a result, scientists can make strong predictions based on animal studies with regard to human exposure to EDCs.

Leon Earl Gray, a senior toxicologist from the U.S. EPA, began investigating the effects of EDCs on our natural environments and found that chemical contaminants were causing developmental abnormalities in fish and wildlife. The likelihood that the effects of these contaminates extended from animal exposure to human exposure was, he said, “estimated with confidence”. He states that, “It is now widely accepted that exposure to EDCs during critical stages of development can induce latent adverse effects and that organisms are uniquely susceptible to EDCs during development”.

The timing of exposure is thought to be critical. Proper development of embryos and fetuses is primarily controlled by hormones, so babies are exceptionally vulnerable to prenatal exposure to EDC’s. When exposed in the early stages of human development, irreversible effects may occur. Such effects include a wide range of reproductive problems (reduced fertility rates, male and female reproductive tract abnormalities, distorted male to female sex ratios, loss of fetus and menstrual problems), early puberty, neurological and behavioral problems, damage to immune functions and several types of cancers. Heightened concern has also erupted with regard to prenatal exposure and it’s association with neurodevelopmental disorders such as a reduced IQ, ADHD and autism.

Mary Snow Wolff, Director of the Center for Children's Environmental Health and Disease Prevention Research (an NIH/EPA-funded multidisciplinary research program), is examining how EDCs affect the development of young girls in the years preceding the onset of puberty. Since estrogen is the primary hormone that drives breast development, as well as breast cancer, EDCs known as xenoestrogen (synthetic estrogens) are being examined as potential triggers.

Exposure to EDCs can occur through contact with pesticides and other chemicals through ingestion of contaminated water, food or air. Many insecticides, herbicides, fumigants, fungicides, and chemicals in detergents, resins and plasticizers are suspected EDCs.

Studies have shown that EDC’s can leach from plastics and they accumulate in fat. As a result, considerable exposure comes from eating fatty foods and fish from noxious water (Natural Resources Defense Council).

Types of the most well known EDCs include DDT (used as a pesticide and essentially banned worldwide), PCB (used as industrial coolants and lubricants and banned in 1977), Bisphenol A (found in baby bottles, plastic food containers, dental materials and in the linings of metal food and infant formula cans), PBDEs (found in flame retardants, carpets, lighting, bedding clothing, cushions and banned in the European Union in 2006).

Despite the fact that some EDCs have been banned, they are still found throughout the globe – as an environmental contaminant, in animals, and in people. Bjorn Munro Jenssen, a professor of Biology from Norway, states that EDCs have become a serious concern for the ecosystem and it’s animals of the Arctic North. After extensive research, Jenssen has concluded that EDC’s have been found in polar bears, beluga whales, Arctic killer whales and foxes.

Although much is known about EDC’s and their effect on both human and animal health, there is still a great deal to learn. However, it has been made clear by countless organizations, including the National Institute of Environmental Health Sciences, and World Health Organization, that the public should not turn a blind eye to the risks of EDC exposure.

What can you do? Below, the National Resources Defense Council offers helpful tips to reduce or avoid exposure to EDCs.

Educate yourself about endocrine disrupters, and educate your family and friends.
Buy organic food whenever possible.
Avoid using pesticides in your home or yard, or on your pet -- use baits or traps instead, keeping your home especially clean to prevent ant or roach infestations.
Find out if pesticides are used in your child's school or day care center and campaign for non-toxic alternatives.
Avoid fatty foods such as cheese and meat whenever possible. EDCs are not flushed from an animal's body. Instead, they are stored and accumulate in fat, which then makes its way up the food chain, to be stored in the fat of humans.
If you eat fish from lakes, rivers, or bays, check with your state to see if they are contaminated.
Avoid heating food in plastic containers, or storing fatty foods in plastic containers or plastic wrap.
Do not give young children soft plastic (PVC) teethers or toys, since these may leach endocrine disrupting chemicals.

Image Courtesy of peasap / CC BY 2.0