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, 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.