Unlike the immediate impact of say, drinking a dose of cyanide, the effects of trace amounts of DDT are variable and hard to connect to a specific case of illness. There is credible evidence though for DDT as having a role in thyroid problems, breast and liver cancer, hypertension, diabetes, and weight gain. Follow the PubMed link I already provided for details and additional information.
Swallow and then swallow some more - FUD.