Mouse study shows fetal exposures may pose long-term risks
Mouse moms exposed late in pregnancy to heavy doses of a carcinogen gave birth to pups that inevitably developed lymphomas and lung cancers, a new study shows. The malignancies generally didn’t show up until the offspring reached the human equivalent of adulthood. The good news: Milk from carcinogen-treated mouse moms posed little added risk.
This demonstration “that very short early-life exposures can have major consequences is very important,” observes toxicologist Linda S. Birnbaum of the Environmental Protection Agency in Research Triangle Park, N.C.
In 2006, David E. Williams and his colleagues at Oregon State University in Corvallis developed an animal model of cancer formation triggered by fetal exposure to pollutants. The team laced the diets of mice with the carcinogen dibenzo[a,l]pyrene — also known as DBP — during just the final two or three days of their three-week pregnancies. This chemical is one of the most toxic