determination of hazardous substances in food basket eggs in tehran, iran: a preliminary study

extensive distribution of hazardous substances in food chain and the deleterious effect of their residues on public health are a great concern of the society. chicken eggs, as one of the most popular food commodities, in different parts of tehran (iran) were analyzed for two groups of hazardous substances including some organochlorine pesticides (oc) such as aldrin, lindane, dieldrin, dichlorodiphenyltrichloroethane, heptachlor and endusulfan) and heavy metals namely mercury (hg), arsenic (as), lead (pb), copper (cu), cadmium (cd), nickel (ni) and chromium (cr). gas chromatography- electron capture detector, hydride-generation atomic absorption spectrometry, cold- vapor atomic absorption spectrometry and conductively coupled plasma atomic optical spectrometry were used to determine the levels of  ocs, as, hg and the others, respectively. for ocs, the results revealed none of the levels were more than maximum residues levels (mrls), but three of them (aldrin, lindane and endusulphan) were detectable. moreover, 100% of 50 eggs had heavy metals with levels higher than limit of detection of the procedure. the levels of pb and hg in all eggs and cd in 47% of samples were more than mrls. it seems that the regular national monitoring of egg producing chain specially the quality of chicken feed should be taken into account seriously in order to safeguard public general health.