No one's used the pesticide Methoxychlor for more than a decade — but according to a new study, it may be harming people for generations to come. A group of researchers at Washington State University have discovered new effects from the pesticide that reach into a subject's epigenome, affecting children and even grandchildren of the initial subject. That ancestral exposure can contribute to adult onset kidney disease, ovarian disease, and obesity in later generations.
Subjects' descendents were more likely to express the harmful genes
Published today in PLOS ONE, the study is part of the growing field of epigenetics, which studies how the body chooses which genetic code to read and which to ignore. Methoxychlor doesn't alter the genome itself, but after exposing rats to the toxin, researchers discovered the subjects' descendants were more likely to express the harmful genes. The effect was particularly pronounced in the female germ line, indicating Methoxychlor is particularly harmful for the descendants of female subjects.
But beyond a single pesticide, the results suggest that ancestral exposures may be a more powerful factor in a person's health than the medical community had previously realized. "The idea that your ancestors' exposures influence your disease has not been seriously considered in our ideas of how disease develops," says Michael Skinner, a WSU professor who led the research team. "Now we need to start considering that as a factor."