While exposure to a single substance like DDT has been shown to create inherited disease susceptibility, a recent study in animals found exposure to multiple different toxicants across generations can amplify those health problems.
In the study, published in the journal Environmental Epigenetics, an initial generation of pregnant rats was exposed to a common fungicide, then their progeny to jet fuel and the following generation to DDT. When those rats were then bred out to a fifth unexposed generation, the incidence of obesity as well as kidney and prostate diseases in those animals were compounded, rising by as much as 70%.
Researchers also found that their epigenetics, molecular processes independent of DNA that influence gene expression, were also greatly altered.
“We looked at multiple-generation exposures because these types of things are going on routinely, and previous research has only looked at single exposures,” said Michael Skinner, a WSU biology professor and the study’s corresponding author. “We found that if multiple generations get different exposures, then eventually there’s an amplification or compounded effect on some diseases.”