Study: DDT exposure affects granddaughters’ breast cancer risk
The insecticide DDT was developed in the 1940s to fight insect-borne diseases such as typhus and malaria. In 1972, the United States banned DDT. It is known to be an endocrine disrupter, meaning that it interferes with hormones and development. Although it was banned, many people were exposed to it, and many are still experiencing effects.
Recently, a new study was published in the journal Cancer Epidemiology, Biomarkers & Prevention. The study found that higher levels of DDT in the bloodstream during pregnancy increased the likelihood of obesity and early-onset menstruation in the tested person’s granddaughters.
This result is based on decades of research. The Public Health Institute’s Child Health and Development Studies (CHDS) were first initiated in 1959. The researchers collected blood samples from approximately 20,000 pregnant women in the San Francisco area. It was at a time when DDT was in heavy use.
Later, the researchers were able to follow up with the children of those women, who are now in their 50s, and some of the original women’s grandchildren, now in their 20s.
These three generations were labeled the “founding” generation (the women who were pregnant when exposed to DDT), the “offspring” generation (the children who were exposed in the womb), and the “grandchild” generation, who were exposed as eggs.
The researchers interviewed the study participants, including 365 granddaughters of the founding generation. They were looking for body mass index (BMI) and their onset of menstruation. Both of these are factors associated with breast cancer and other disorders such as diabetes and high blood pressure.
BMI and age of menstruation worse among those exposed
When factoring in the DDT levels found in the founding generation’s blood back in 1959, the researchers discovered that the grandchild generation was two or three times as likely as average to be obese and twice as likely than average to menstruate before age 11. This was consistent with international patterns.
The study concluded that DDT, and perhaps other endocrine disruptors, potentially increases the risk of breast cancer, even in the grandchild generation.
“We already know that it’s nearly impossible to avoid exposures to many common environmental chemicals that are endocrine disruptors. Now our study shows for the first time in people that environmental chemicals like DDT may also pose health threats to our grandchildren,” said the senior author of the study.
Chemicals that our society uses to solve one problem sometimes create another. When a manufacturer, distributor or retailer brings a dangerous product to market, they may be found liable for any injuries that product causes.