The results of a study, which was conducted over more than 50 years and involved three generations of American women, suggest that women who were exposed to the estrogen-mimicking chemical DDT while in the womb are nearly FOUR times more likely to develop breast cancer.
Today, many women maintain hints of DDT in their bodies due to the pervasive use of the chemical before it was banned in the United States in the 1970s. It was sprayed from planes and trucks onto fields, into cities, and over residences, with or without permission. It was even advertised for use in homes. The pesticide that inspired Rachel Carson’s Silent Spring killed not only harmful insects, but beneficial insects, fish, and birds. Now, decades later, it’s hurting women. Moreover, parts of the world, including Sub-Saharan Africa, continue to use the chemical to combat malaria.
“We have to remember that children born today are exposed to these chemicals from birth. Perhaps even before birth. Now what is going to happen to them in adult life as a result of that exposure? We simply don’t know.”
-Rachel Carson, 1963 interview
The study tracked mothers and daughters over the course of 54 years. The degree of prenatal exposure to DDT was recorded and analyzed. Of the daughters tracked, 118 were diagnosed with breast cancer by the age of 52, and 354 were not. When other risk factors were accounted for, researchers determined that the women whose mothers were exposed to high amounts of DDT during pregnancy were 3.7 times more likely to develop breast cancer. To offer perspective, women who are heavy drinkers are 1.5 times more likely, and women with BRCA mutations are 5 times as likely to develop breast cancer than women without.
Scientists theorize that exposure to DDT in utero could alter a person’s genes and ultimately the formation of the breast tissue, increasing risk. The hope is that by continuing to study prenatal conditions, we will gain an understanding of who gets breast cancer and why. With that knowledge, we have a much better chance of identifying environmental factors that cause breast cancer — and stopping them in their tracks.