According to a new study, women that had a high DDT exposure during their pregnancy gave birth to girls that were four times more likely to be diagnosed with breast cancer later in their life.
The recent research is one of the studies that revealed the strongest association between DDT and cancer, study authors said. They also disclosed that they had employed real blood samples taken from mother 50 years ago, rather than basing their findings on some surveys and faulty memories.
Dr. Barbara Cohn, co-author of the study and researcher at the Public Health Institute in Berkeley, Calif., explained that she and her colleagues were intrigued by past studies that had linked the common insecticide with breast cancer. So, they started a study on humans to back the idea.
“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,”
Dr. Cohn added.
In the U.S., more than 200,000 female patients are diagnosed with breast cancer, while more than 40,000 die from it every year. Scientists had long suspected poor diet, hormonal imbalance, obesity, and even genetic disorders. But only a few studies added chemicals including those in cigarettes or drugs to that list.
Nevertheless, no study particularly focused on a DDT-cancer risk link in pregnant women. And if the results are correct, many women may find that the cause of their breast cancer was their mothers’ exposure to DDT especially in the 1960s.
Researchers also expressed their concerns over frantic use of DDT in developing countries and its consequences of the next generation of women.
The research team analyzed blood samples taken from about 20,000 pregnant women from 1959 to 1967. Those women brought to the world 9,300 girls during that period. Researchers found that though mothers with high levels of DDT in their blood had no history of breast cancer their daughters’ risk of developing the disease was fourfold.
DDT, or dichlorodiphenyltrichloroethane, was first used in North America in 1945 to fight off insects that carried tropical disease such as malaria. During the 1950s and 1960s the insecticide had a widespread use, but its popularity declined when people learned that it harmed birds and small animals, as well. In 1972, the chemical was finally banned in the U.S. for agricultural purposes.
Study authors caution that women who were heavily exposed to DDT in their mothers’ wombs, especially in the 1960s, have a high risk of breast cancer and they should request medical checkups.
Image Source: Advisory Committee on Pesticides