Autism is increasing due in part to new DNA mutations that neither parent had. DNA mutations can result from exposure to carcinogens such as 4-Hydroxynonanol and 4-Hydroxyhexanol. These two compounds can also derive from oxidation of vegetable-oil derived polyunsaturated (PUFA) fats. Consumption of PUFAs has increased dramatically over the last 50 years, as much as ten fold. Such excessive consumption of PUFAs is very possibly leading to reactions that generate carcinogens in our body tissues. During the production of eggs and sperm, these carcinogens may not result in cancer but rather in mutations to DNA . This line of reasoning deserves serious consideration as a potential major factor in the cause of autism.