Levels of organochlorine pesticides in the blood of people living in areas of intensive pesticide use in Sudan

Ninety-six human blood samples were collected from six locations that represent areas of intensive pesticide use in Sudan, which included irrigated cotton schemes (Wad Medani, Hasaheesa, Elmanagil, and Elfaw) and sugarcane schemes (Kenana and Gunaid). Blood samples were analyzed for organochlorine pesticide residues by gas liquid chromatography (GLC) equipped with an electron capture detector (ECD). Residues of p,p′-dichlorodiphenyldichloroethylene (DDE), heptachlor epoxide, γ-HCH, and dieldrin were detected in blood from all locations surveyed. Aldrin was not detected in any of the samples analyzed, probably due to its conversion to dieldrin. The levels of total organochlorine burden detected were higher in the blood from people in the irrigated cotton schemes (mean 261 ng ml−1, range 38–641 ng ml−1) than in the blood of people from the irrigated sugarcane schemes (mean 204 ng ml−1, range 59–365 ng ml−1). The highest levels of heptachlor epoxide (170 ng ml−1) and γ-HCH (92 ng ml−1) were observed in blood samples from Hasaheesa, while the highest levels of DDE (618 ng ml−1) and dieldrin (82 ng ml−1) were observed in blood samples from Wad Medani and Kenana, respectively. The organochlorine levels in blood samples seemed to decrease with increasing distance from the old irrigated cotton schemes (Wad Medani, Hasaheesa, and Elmanagil) where the heavy application of these pesticides took place historically.