Chlorinated Pesticide Residues in Milk of Iranian Nursing Mothers

One-hundred-thirty-one samples of human milk were collected during October, 1974, to January, 1976, throughout the Tehran area.Sources included four maternity hospitals as well as individual nursing mothers outside of hospitals.The samples were collected 1 to 8 days after child birth from women 14 to 42 yr old and from all social strata.The samples were analyzed for chlorinated pesticide residues by gas-liquid chromatography.Insecticides 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) (with its metabolites), isomer of benzene hexachloride (5' BHC), and dieldrin were detected in varying concentration in 101, 108, and 47 samples, respectively.The means and ranges were .024(.001 to .333)ppm, .008(.001 to .046)ppm, and .011(.001 to .028)ppm.These concentrations in human milk represented insecticidal ingestion by infants.The mean dieldrin exceeded the World Health Organization limit and may pose a health hazard.There was no significant relationship between economic status of donors and pesticide in the milk; however, milk from the older nursing mothers contained more DDT than that from young mothers.nated pesticide residues in Iran,In this investigation we established the degree of insecticide exposure to which infants receiving Iranian mothers' milk are subjected. MATERIALS AND METHODSOne-hundred-thirty-one samples of milk were collected from October, 1974, through January, 1976, from four maternity hospitals and elsewhere in the Tehran area and brought to the laboratory of Toxicology, University of Tehran.The samples were analyzed by the method of Sodergren (1): Five microliters hexane extract were injected into a Varian Aerograph series 1400 gas chromatograph equipped with a Ni 6a electron capture detector and a 151.8 x 3.2 x 2 mm pyrex glass columns of 10% OV-1 on 100/120 Varaport 30 and 5% DC-200 on 60/80 Chromosorb W. The operating conditions were: column temperature 180 C, injector temperature 220 C, detector temperature 240 C, N2 flow rate 40 ml/min, attenuation set at 2 X 10 qo, and recorder chart speed .2cm/min.The residues in the samples were identified by reference to retention times of chromatographic peaks of standard solutions of organochlorine pesticides supplied by Interscience Inc. Quantitation was by comparing peak areas of