The cause of the debilitating gynaecological condition endometriosis in not known but new research carried out in the USA has discovered a link between the condition and two so-called organochlorine pesticides. The use of organic chlorinated compounds as pesticides, including DDT, has been banned for many years due to concerns about their effects on the environment and human and animal health.
Endometriosis affects up to 10 per cent of women of reproductive-age. It occurs when the tissue that lines the inside of the uterus or womb grows in other areas of the body, usually in the pelvic region, and attaches to other structures or organs. The condition most often affects the ovaries, fallopian tubes and lining of the pelvic cavity and causes inflammation, scarring and adhesions. The most common symptoms include chronic pelvic pain, painful menstrual periods and infertility.
The study was carried out by scientists at the Fred Hutchinson Cancer Research Centre in Seattle and the University of Washington. It involved 248 women newly diagnosed with endometriosis and, for comparison, 538 women without the disease who acted as the control group. In blood samples of both groups, elevated levels of the two pesticides, mirex and beta HCH, were found to correlate with an increased risk of endometriosis.
The principal investigator of the study was Dr Victoria Holt, a joint member of the Epidemiology Research Unit in the Public Health Sciences Division at Fred Hutchinson and Professor of Epidemiology at the University Of Washington School of Public Health.The principal investigator of the study was Victoria Holt, Ph.D., a joint member of the Epidemiology Research Unit in the Public Health Sciences Division at Fred Hutch and professor of epidemiology at the University of Washington School of Public Health.
"For many women, the symptoms of endometriosis can be chronic and debilitating, negatively affecting health-related quality of life, personal relationships and work productivity,” she said.
"Since endometriosis is an oestrogen-driven condition, we were interested in investigating the role of environmental chemicals that have oestrogenic properties, such as organochlorine pesticides, on the risk of the disease.”
"This research is important, as endometriosis is a serious condition that can adversely affect the quality of a woman's life, yet we still do not have a clear understanding of why endometriosis develops in some women but not in others," Holt said. "Our study provides another piece of the puzzle."
"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," Dr Upson said. "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."
Previous studies have suggested that organochlorine pesticides may act as hormone disruptors, altering the function of the uterus and ovaries, as well as hormone production.
The findings of this new study are published online ahead of the print issue of Environmental Health Perspectives, a journal of the National Institute of Environmental Health Sciences, part of the National Institutes of Health in the USA.