Endometriosis is a painful and often devastating condition that can cause infertility when a woman's uterine tissue grows outside the uterus. Scientists have never been sure why some women have the condition and others don't, but a new study has discovered a potential link: pesticide exposure.
The study looked at nearly 250 women with surgically confirmed endometriosis and measured the levels of two pesticides in their blood: mirex and beta HCH. Although both of these chemicals have been banned for use in the U.S. for decades, they persist in some fish and dairy products.
Researchers found that women with the highest levels of mirex in their blood had a 50 percent increased risk for endometriosis, and women exposed to high levels of beta HCH had a 30 to 70 percent increased risk.
The numbers are alarming because the study shows that pesticides which persist in the environment can pose significant health risks to reproductive-aged women, even if the pesticides were banned before those women were even born. The study looked at women between the ages of 18 and 49, and mirex, for example, was banned in 1976 in the U.S.
Endometriosis is considered an estrogen dependent disease, and the study's hypothesis was that persistent environmental pesticides that exhibit hormonal properties, including mirex and beta HCH, could contribute to the disease.
Both these pesticides fall under the broader umbrella group known as organochlorides, of which DDT is the most commonly known example. Organochlorides, including DDT, mirex, and others, were widely used from the late 1940s through the 1970s and '80s, but were banned in the U.S. when it was discovered that they were toxic and extremely persistent organic pollutants. The worst of these have been linked to Parkinsons, breast cancer, and immune, reproductive, and nervous system damage.
This new research, conducted by the Department of Epidemiology, School of Public Health at the University of Washington, shows that even nearly 40 years after these chemicals were banned from use, the repercussions of their toxicity are still being felt, generations later.
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