THE IMPORTANCE OF MEASURED INTAKE IN ASSESSING EXPOSURE OF BREAST-FEDINFANTS TO ORGANOCHLORINES

Objectives: To estimate infants' intake of organochlorines (OCs) from their measured intake of breast milk; to compare these with the accept able daily intakes (ADIs) set by the World Health Organization (WHO). Design: Primiparous nursing mothers were recruited from either an indu strial or rural area between January and November 1992. Setting: Mothe rs volunteered in response to information displayed at their Infant We lfare Centre. All sampling was undertaken in the subject's home. Subje cts: The sole entry criterion was primiparity. Three breast milk sampl es were collected at one month intervals from each mother. OC levels w ere measured on a milk fat basis by gas chromatograph-mass spectromete r and individual milk intakes were used to determine the infant's dail y OC intake. Of the 23 mothers who entered the study, 17 finished, res ulting in 57 samples for intake determination. Results: Some intakes o f hexachlorobenzene (HCB), chlordane, dieldrin and heptachlor epoxide (HE) exceeded the ADI. High OC levels in breast milk did not necessari ly result in a high intake for the infant. Conclusions: Assessment of the exposure of infants to OC contaminants in breast milk requires an accurate estimate of OC intake. Intakes estimated using inferred rathe r than measured values for milk fat and milk intake are not reliable i ndicators of actual intakes.