Two organochlorine pesticides have been linked to an increased risk of endometriosis, a painful condition where excess tissue that lines the womb grows outside of the uterus on other organs or structures in the body.
They looked at 248 women who had been recently diagnosed with endometriosis and 538 women who did not have the condition. They discovered that women who had high exposure to the pesticides had a 30 to 70 percent increase in endometriosis risk.
"We found it interesting that despite organochlorine pesticides being restricted in use or banned in the U.S. for the past several decades, these chemicals were detectable in the blood samples of women in our study and were associated with increased endometriosis risk," lead author Kristen Upson, a postdoctoral fellow at the Epidemiology Branch of the National Institute of Environmental Health Sciences, said in a press release. "The take-home message from our study is that persistent environmental chemicals, even those used in the past, may affect the health of the current generation of reproductive-age women with regard to a hormonally driven disease."
Women with the highest levels of mirex had a 50 percent increased risk for endometrosis, while those with the highest exposure to beta HCH had a 30 to 70 percent higher chance of developing the disease.
Endometriosis affects up to 10 percent of reproductive-aged women, the authors noted. The excess tissues usually grow on the ovaries, fallopian tubes and lining of the pelvic cavity. However, tissue can also grow on the vagina, cervix, vulva, bladder or rectum. In rarer cases, additional tissue can be found on the lungs, brain and skin.
Symptoms can include very painful menstrual cramps that can get worse over time, chronic pain in the lower back and pelvis, pain during or after sex, intestinal pain, painful bowel movements or urination during menstrual periods, spotting or bleeding between periods, infertility or not being able to get pregnant, fatigue, and diarrhea, constipation, bloating, or nausea especially during menstrual periods.
"For many women, the symptoms of endometriosis can be chronic and debilitating, negatively affecting health-related quality of life, personal relationships and work productivity," Upson said.
The condition has been linked to other health problems including allergies, asthma and chemical sensitivities. Women who suffer from endometriosis may also have other autoimmune diseases that cause the body to attack itself instead, including hypothyroidism, multiple sclerosis and lupus. Chronic fatigue syndrome, fibromyalgia, increased risk of getting infections and mononucleosis (mono), mitral valve prolapsed and frequent yeast infections have also been connected to endometriosis. There has also been an association with the disease to ovarian, breast, endocrine, kidney, thyroid, brain, and colon cancers as well as melanoma and non-Hodgkin's lymphoma.
"We hope our findings will help inform current global policymaking to reduce or eliminate their use," said Upson.
The article was published in Environmental Health Perspectives on Nov. 5.