Report: Some Chemicals May Alter Gene Function for Several Generations
WASHINGTON – The harmful effects of some chemicals can be passed down not only to children, but also to grandchildren and even great-grandchildren, according to a new EWG report on the growing body of transgenerational toxicity research.
The impact of toxic chemicals on generations of offspring with no direct exposure to the contaminant is known as a transgenerational effect. A limited number of new studies suggest that short-term exposures to some chemicals during pregnancy can cause reproductive system damages, alter body weight, and even increase the risk of cancer for great-grandchildren of exposed animals.
“New science suggests that exposure to contaminants during pregnancy can have health impacts decades later,” said EWG Senior Analyst Sonya Lunder, author of the report. “We need to know more about this phenomenon in order to protect our children and great-grandchildren from the effects of harmful pollutants.”
Groundbreaking research by Mohan Manikkam and Michael Skinner of Washington State University at Pullman helped establish the principle of transgenerational toxicity by showing how toxic chemicals affect subsequent generations that are not directly exposed. In one study, the researchers tested the transgenerational impacts of mixtures of chemicals that people are commonly exposed to in everyday life, including bug repellents, plastics additives and jet fuel. After exposing pregnant rats, they bred three subsequent generations of animals with no exposure to the contaminants.
Despite no direct exposure to the chemicals, the third-generation rats had damaged reproductive systems. Females had an earlier onset of puberty and fewer undeveloped eggs in their ovaries. Male rats had higher levels of dead sperm.
Very few studies of multigenerational health effects in people have been conducted so far. More experimental research is necessary to learn more about this phenomenon and shed light on several concerning health trends including infertility, obesity, and even cancer.