Pregnant women who are highly exposed to common environmental chemicals -- polyfluoroalkyl compounds (PFCs) -- have babies that are smaller at birth and larger at 20 months of age, according to a new study. PFCs are used in the production of fluoropolymers and are found widely in protective coatings of packaging products, clothes, furniture and non-stick cookware. They are persistent compounds found abundantly in the environment and human exposure is common. PFCs have been detected in human sera, breast milk and cord blood.