DDT is very stable and bioaccumulates. I don't know how much exposure a woman giving birth in the 2000s would have relative to earlier years, but I don't think

DDT is very stable and bioaccumulates. I don't know how much exposure a woman giving birth in the 2000s would have relative to earlier years, but I don't think you can assume it's that low. My instinct is that based on the study's moderate effect size and the lack of strong birth order effects or links to breastfeeding in autism, this effect can't explain the dramatic rise in autism diagnoses in the past several decades. I'm not a scientist, so take this with a grain of salt.