Looking for Proof in the Wrong Generation?

The article in this issue "Grandmaternal Perinatal Serum DDT in Relation to Granddaughter Early Menarche and Adult Obesity: Three Generations in the Child Health and Development Studies Cohort," by Cirillo and colleagues, is the first to report multigenerational health effects in granddaughters stemming from early life exposures to the pesticide o,p'-DDT in grandmothers. Health effects associated with F environmental chemical exposures in multiple generations have been reported in rodent studies, but not in humans. The striking finding in this body of work by Cohn and her colleagues is that the granddaughters were never directly exposed to o,p'-DDT-only their grandmothers were, potentially when they were adolescents. The increased rise of obesity and early menarche due to o,p'-DDT exposures generations earlier may help explain why it has been so difficult to describe environmental contributors of disease. Have we been looking for exposures in the wrong generation?.