determination of dioxins and polychlorinated biphenyls levels in milk samples from capital and north of iran

High levels of dioxins and dioxin-like compounds in the food and their adverse effects on human health are of increasing concern. since milk is one of the most essential human nutritional resources, the present study aims at determining dioxins and pcbs in raw milk samples from four farms in north of iran and raw and pasteurized samples from three farms and five dairy factories in vicinity of tehran (capital of iran). total toxic equivalence (teq) of dioxin and pcbs have been determined, using the dr-calux® bioassay. results reveal that all samples are contaminated with dioxins and pcbs, comparatively. the total dioxins and pcbs levels in raw milk samples from the north range from 4.08 to 0.97 pg/gfat and for the raw samples and pasteurized samples from tehran province from 1.89 to 0.63 pg/gfat and 0.1 to 0.03 pg/gfat, respectively. the mean concentration of dioxins/pcbs is higher in samples from the north of iran. this may be because of the common method of removing domestic and agricultural disposal in this area.