RESUMO
PCBs were detected using gas liquid chromatography in 540 human milk samples coming from 180 mothers living in three provinces of the Southern Region of Chile, collected in three different stages of lactation. Samples coming from 33 women (18.3 per cent) had PCBs residues, with a median level of 1.28 (range 0,09-84.83) ppm (milk fat basis). Ten of these women delivered to their offspring more than 0.01 mg of PCB/kg body weight/day, level considered hazardous to child helath. PCB levels tended to increase toward the third sampling stage. These levels were not related to women`s age but primiparae had higher levels than multiparae. It is concluded that a surveillance system in biological samples is necessary to oversee PCB levels in different regions of the country