Exposure to endocrine disrupting compounds can lead to trouble
As the public has become more aware of the harmful effects of toxins in the environment, grassroots efforts have brought about positive changes, such as the banning of bisphenol A, or BPA, in plastic baby bottles.
That’s a positive step, said Dr. John Peterson Myers, who spoke April 9 at Catawba College’s Center for the Environment. However, given the serious public health threat posed by widespread exposure to such endocrine disrupting compounds, or EDCs, we need to do more.
An endocrine disrupting compound is a chemical or mixture of chemicals that interferes with any aspect of hormone action. The health risk caused by EDCs has recently been recognized by the World Health Organization.
Hundreds of chemicals in common use are known to disrupt endocrine function—and most haven’t been tested for safety, Myers said. Six of the biggest known offenders are BPA, atrazine, perfluorinated compounds, phthalates, organotins and perchlorate.
Epidemics that may be driven in part by EDCs include hormone-related cancers, endometriosis, autoimmunity, learning disabilities, ADHD, fibroids and polycystic ovaries, degenerative diseases, preterm birth, obesity and diabetes, heart disease, asthma, infertility and autism.
Recent scientific advances in understanding what causes endocrine disruption are giving us the opportunity to prevent diseases that 20 years ago we wouldn’t have imagined might be preventable, Myers said.
A 1996 book co-authored by Myers called “Our Stolen Future” brought worldwide attention to endocrine disruption and attracted hundreds of millions of dollars for scientific research. The research was fruitful, and now, we must act on the research findings, Myers said.
It’s not only human health that is suffering because of EDCs. Wildlife is also affected by the ubiquitous toxins in the environment. One dramatic study led by Tyrone Hayes showed that exposure to only 2.5 parts per billion of atrazine, a widely-used herbicide, caused 10 percent of a population of male frogs to become functional females—genetic males capable of reproducing. For humans, the Environmental Protection Agency has declared that safe exposure to atrazine is 100 parts per billion. But regulatory bodies such as the EPA, Myers warns, are using outdated science.
Our goal as a society should be, through policy interventions, to reduce exposures to EDCs like atrazine as a way to prevent disease. Even low-dose exposure to EDCs in the womb can lay the groundwork for adult disease, Myers said.
Myers believes outmoded science has put us in danger. “The tools we have used to tell us what is safe and what isn’t have failed us,” he said. Traditional methods used by the Food and Drug Administration and the Environmental Protection Agency are decades out of date and ignore important advances in molecular biology, Myers said.
He explained that scientists have learned that increasing exposure to EDCs does not necessarily produce the expected results. In one study, two mice, one exposed to synthetic estrogen, developed dramatically different body types even though they had the same caloric intake and activity level. The mouse exposed to one part per billion of the chemical, as opposed to the control mouse with no exposure, became obese. Counter-intuitively, higher levels of exposure actually created thinner mice.
Myers and others have come up with a system of tests to detect whether a new compound will cause endocrine disruption. That means it’s now possible to pursue “green chemistry” by giving chemists the tools to develop safer molecules with which to replace EDCs in consumer products.
Asked about practical advice for avoiding EDCs, Myers said the recommendations in “Our Stolen Future” still applied. He offered the following suggestions:
• Eat low on the food chain, organic when possible
• Avoid products with BPA
• Don’t microwave in plastic
• Handle receipts (such as those that come out of the ATM) as little as possible because they contain high levels of BPA
• Find non-chemical alternatives to control household pests
Those interested in keeping up with current research in the area of EDCs can subscribe to Environmental Health News free of charge. Go to www.EnvironmentalHealthNews.org.