Bio-monitoring of persistent organochlorines in human milk and blood samples from sub-Himalayan region of India.

In the present study, concentrations of organochlorine pesticide residues viz. Dichlorodiphenyltrichloroethane and its metabolites (DDTs) and Hexachlorocyclohexane isomers (HCHs) in human breast milk and human blood samples, collected from several high altitude regions of Garhwal Himalaya in Uttarakhand, India viz. Devprayag, Chamoli, Uttarkashi, Joshimath, Bhatwari and Gangnani (altitude ranging from 472 to 1,982 m above sea level) were determined. Mean concentrations of HCH and DDT in human milk samples ranged from 4.53 to 34.32 mg/kg and 6.09 to 12.98 mg/kg, respectively. While the human blood showed mean values ranging from 6.64 to 281.7 μg/L and 12.37 to 104.10 μg/L for HCH and DDT, respectively. The study showed much higher concentrations of organochlorine residue contamination in the Garhwal region as compared to other parts of India. Risk assessments for infants were also calculated and were found within WHO limits.