SIMULTANEOUS PRESENCE OF PYRETHROID AND ORGANOCHLORINE RESIDUES IN HUMAN BREAST MILK FROM NADIA,WEST BENGAL, INDIA

Concentration of major group of Pesticides such as organochlorines, pyrethroids and neonicotinoids were measured in fifty six human breast milk samples collected from Nadia district, West Bengal, India during 2013–2014. Despite being the fact that most organochlorine pesticides are banned and restricted for use in India, residues of these compounds continue to be present in the environment. Over the past few decades, it has been found that level of organochlorine have declined in human breast milk. Based on this concern, the present study was carried out to understand this trend and to assess the level of different pesticide compounds in human breast milk. Analysis was carried out with the help of Gas chromatography/mass spectrometry (GCMS) and liquid chromatography/ mass spectrometry (LCMS) using modified Quecher's method for pesticide residue analysis. The method was evaluated for 23 different pesticides and typical recovery was found in the range of 90 ± 10 %. However no measurable concentrations of neonicotinoids compounds were found in the breast milk samples while organochlorine compounds and three synthetic pyrethroid were found to be present in human milk samples. Among the organochlorines analyzed, DDTs (21.67 ngg^-1 ww average value) were the predominant contaminants, followed by HCHs (14.71 ngg^-1 ww average value). Pyrethroids identified were Bifenthrin, Lambda cyhalothrin and Permethrin (average value 7.93, 28.41 and 23.04 ngg^-1 ww respectively). This is the first report to identify pyrethroid in human milk from Kolkata samples. Finally, daily intake estimation of nursing infants was calculated and compared with acceptable WHO levels. Estimated daily intake shows that some infants are exposed to OCs to a greater extent, particularly HCHs than the guideline standard. The estimated daily intakes for nursing infants were always below the acceptable daily intake levels in case of pyrethroids except for lambda cyhalothrin where concentrations were very close to the maximum acceptable levels. We therefore raise a concern based on toxicant interactions, due to the presence of three different pyrethroids and organochlorines.