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DDT Still Haunts Us: Effects of Breathing in this Organochloride

Aug 21, 2015 11:07AM ● By Cate Reynolds
Everyone knows the term “you are what you eat.” If you feed yourself junk you’ll feel like junk. However, new research shows that you are also what you breathe. And what your mother may have breathed.

According to a study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM), women who were exposed to higher levels of the pesticide DDT in utero are nearly four times more likely to be diagnosed with breast cancer than women with lower exposure before birth. In other words ladies, if your mother was exposed while pregnant with you, you may be more susceptible to breast cancer.

DDT (dichloro-diphenyl-trichloroethane) is a colorless, crystalline, tasteless, and almost odorless organochloride known for its insecticidal properties. It was developed in the 1940s and effectively used to combat malaria, typhus, and the other insect-borne human diseases among both military and civilian populations. Due to mounting evidence of the pesticide’s declining benefits as well as the suspected environmental and toxicological effects, DDT was banned in the U.S and many other countries in the 1970s. (DDT is still used, however, in parts of Asia and Africa where combating diseases such as malaria is considered the priority.)

One of the study’s authors, Barbara A. Cohn, Ph.D., from the Public Health Institute in Berkeley, California, says that “this 54-year study is the first to provide direct evidence that chemical exposures for pregnant women may have lifelong consequences for their daughters’ breast cancer risk.” Cohn goes on to say, “Environmental chemicals have long been suspected causes of breast cancer, but until now, there have been few human studies to support this idea.”

Operative phrase, “until now.” The Child Health and Development Studies (CHDS) have been conducting a study for 54 years, tracking 20,754 pregnancies since the beginning of utero. During this study, participants gave birth to 9,300 daughters. To track the levels of DDT exposure in utero, scientists took blood samples of the pregnant mothers during or immediately after child birth. The scientists reconnected with the daughters once they reached the age of 52, a peak age for breast cancer diagnosis, and the results were astonishing.

Researchers found that women who were exposed to higher levels of o, p’-DDT, a more estrogenic form of DDT, had a higher risk of being diagnosed with a more advanced stage of breast cancer. On top of that, women exposed to high amounts of o, p’ -DDT were more likely to develop HER2-positive breast cancer. HER2 is where the cancer cells have a gene mutation that produces an excess amount of a specific protein, and it was found that DDT activated the HER2 protein.

“This study calls for a new emphasis on finding and controlling environmental causes of breast cancer that operate in the womb,” says Cohn. It’s a pretty scary thought that even in the most protected vessel one can think of, the womb; there are still risks.

—Jane Bornstein