Toxicants in household products and water supply bioaccumulate in food chains, plants, animals, and people. These chemicals, used in food packaging, non-stick coating, and stain repellents are known carcinogens, immune stressors, and endocrine disruptors. They affect the delicate hormonal balance critical for sexual differentiation and organogenesis. Do these chemicals affect females and males differently and what are the consequences of long-term exposures? We are exposing male and female adolescent fruit flies to these toxicants, microdissecting their brains and quantifying gene activity to better understand how these pervasive and possibly dangerous chemicals affect brain development and physiology of each sex.