Two pesticides are
associated with an increased risk of endometriosis, a common health problem
that occurs in up to 10% of reproductive-age women, according to a new study.
In endometriosis, tissue
that lines the uterus grows outside the womb, leading to pain and infertility
in some cases. The condition affects 5 million women in the United States.
Researchers compared 248
women newly diagnosed with endometriosis and 538 women without the condition
and found that those with higher exposure to two pesticides classified as
"organochlorine" had a 30% to 70% higher risk of endometriosis.
The two pesticides are
beta-hexachlorocyclohexane and mirex, according to the study published online in
the journal Environmental Health Perspectives.
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," study lead author
Kristen Upson, said in a Fred Hutchinson Cancer Research Centre news release.
Detectable in blood samples
"We found it
interesting that despite organochlorine pesticides being restricted in use or
banned in the US 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," Upson said.
Upson was a predoctoral
research fellow in epidemiology at the centre and the University of Washington
when the study was conducted, and is currently a postdoctoral fellow at the
epidemiology branch of the US National Institute of Environmental Health
"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," Upson said.
Although the study found an
association between exposure to two specific pesticides and a higher risk of
developing endometriosis, it did not prove a cause-and-effect relationship.
Victoria Holt, a joint member of the epidemiology research unit at Hutchinson
and professor of epidemiology at the University of Washington School of Public
Health, said in the news release: "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. Our study provides
another piece of the puzzle."
The US Office on Women's
Health has more about endometriosis.