A long term study conducted by US researchers has found a connection between levels of DDT pesticide and breast cancer – women with high levels of DDT in their body were four times more likely to develop breast cancer.
DDT has been formulated in almost every conceivable form, including solutions in xylene or petroleum distillates, emulsifiable concentrates, water-wettable powders, granules, aerosols, smoke candles and charges for vaporizers and lotions. First synthesized in 1874, DDT’s insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. It was used for decades to control malaria, and then, as a pesticide. As early as the 1940s, scientists in the U.S. had begun expressing concern over possible hazards associated with DDT, and in the 1950s the government began tightening some of the regulations governing its use. The US banned in in 1972, but the substance is still used extensively in Asia and Africa.
“Environmental chemicals have long been suspected causes of breast cancer, but until now, there have been few human studies to support this idea,” said Barbara Cohn of the Public Health Institute in Berkeley, California, co-author of the study published Tuesday in the Journal of Clinical Endocrinology and Metabolism.
Although DDT is considered a probable carcinogen, it’s the first time a direct connection was observed between it and cancer.
“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.”
The researchers studied data from a California program called Child Health and Development Studies, which studied 20,754 pregnancies from 1969 to 1967. During that time, DDT was still used and accumulated in foods like milk or butter.
“Independent of the mother’s history of breast cancer, elevated levels of DDT in the mother’s blood were associated with a nearly four-fold increase in the daughter’s risk of breast cancer,” said the study. “Among the women who were diagnosed with breast cancer, 83 percent had estrogen-receptor positive breast cancer, a form of cancer that may receive signals from the hormone estrogen to promote tumor growth.”
Also, by examining the levels of DDT in the mother’s blood, doctors were able to determine with startling accuracy which of the daughters would develop breast cancer later in life. When you consider that billions of people are still exposed to this chemical substance, the implications become evident – we need to find a way to phase DDT out of use.
“Our findings should prompt additional clinical and laboratory studies that can lead to prevention, early detection and treatment of DDT-associated breast cancer in the many generations of women who were exposed in the womb,” the research concludes.