An epidemic of precocious development in Puerto Rican children.

An alarming incidence of premature sexual development has been reported in Puerto Rico during the last 7 years. A significant increment of premature thelarche, premature pubarche, prepubertal breast enlargement in boys, and precocious pseudopuberty in girls has been observed throughout the island. Several food specimens analyzed by chromatography and cytosol receptor assay revealed significant levels of estradiol equivalent in some meat samples. We suspect that the early sexual development is caused by exogenous estrogen contamination in the food ingested by the children and by their mothers.