Pesticide levels in head hair samples of Cretan population as an indicator of present and past exposure.

In the present work we assessed chronic exposure of different working population groups of Messara and Sitia districts, Crete, Greece, to common currently used pesticides (diazinon, fenthion, methyl parathion and malathion) and two banned pesticides hexachlorocyclohexane (HCH) and DDT. The study population (211 persons, 110 females and 101 males) was divided to three groups; people working in greenhouses, animal breeders and people working in open cultivations. Methanolic extraction of pulverized hair was used for organophosphate pesticides extraction, followed by liquid-liquid extraction with water-ethyl acetate as a clean up step. The extraction of organochlorine pollutants was performed by acidic hydrolysis of the hair matrix followed by liquid-liquid and solid phase extraction. The levels of the aforementioned pesticides were measured by GC-ECD and gas chromatography-mass spectrometry (GC-MS). The median concentrations of a-HCH, HCB, lindane, opDDE, ppDDE, opDDD, ppDDD + opDDT and ppDDT were determined at 7.2, 2.2, 70.2, 2.7, 5.7, 3.1, 2.6 and 23.2 pg/mg. The median concentration of total HCHs and DDTs detected in the three working groups were: 95.0 and 8.9 pg/mg for the greenhouse workers, 38.2 and 3.3 pg/mg for the animal breeders and 24.1 and 5.2 pg/mg for the open cultivation group. Ten head hair samples were positive for diazinon at a mean concentration of 2.8 pg/mg. Fenthion, methyl parathion and malathion were not detected. Our results demonstrated the ability to assess chronic human past pesticides exposure, offering valuable information to epidemiological clinical studies.