Laura Vandenberg, Ph.D.
University of Massachusetts, Amherst
K22ES025811, R21ES026395, R01ES021394
Prenatal exposure to chemicals used in unconventional oil and gas (UOG) extraction, also known as fracking, altered mammary gland development in female mice, according to a new study by NIEHS grantees. The researchers saw effects from a mixture of 23 commonly used UOG chemicals at levels that were observed in drinking water in regions experiencing UOG operations.
Researchers added the UOG mixture or a control substance without UOG chemicals to the drinking water of pregnant mice. Chemical doses were equivalent to either concentrations measured in drinking water near drilling operations or measurements in industry wastewater. After the pups were born, the team analyzed the mammary tissue of females at two points in time — before puberty and in early adulthood.
The researchers reported striking changes in the morphology of the pups' mammary glands in early adulthood. In UOG-exposed mice, they saw structures resembling terminal end buds, which are mammary structures that are normally only found at puberty. The structures were not seen in the control mice. Further examination with tissue-level and immunohistochemical tools revealed ducts with excessive layers of epithelial cells that might have been precancerous. No changes were observed in the mice before puberty.
According to the authors, their results suggested that the mammary gland is sensitive to mixtures of chemicals currently used in UOG production, and more research is needed to examine the potential risk of breast cancer in women living near UOG operations.
Citation: Sapouckey SA, Kassotis CD, Nagel SC, Vandenberg LN. 2018. Prenatal exposure to unconventional oil and gas operation chemical mixtures altered mammary gland development in adult female mice. Endocrinology 159(3):1277-1289.