Abstract
Organochlorine pesticides (OCPs) used in agriculture and for public health purposes were banned in Thailand over the past decade; however, their persistent residues have been found in several agricultural areas of the country. This may result in adverse effects to human populations. This study investigated the concentration of organochlorine pesticides residues (OCPRs) in surface water and evaluated the potential cancer risk associated with dermal contact of the local fisherman fishing in the Khlong 7 canal, Rangsit agricultural area, central Thailand. Water samples were extracted using liquid-liquid extraction (LLE) and then analyzed by gas chromatography with microelectron capture detector (μ -ECD). The results show that low concentrations of OCPRs were detected in parts per billion (ppb or ng/ml) levels, that is, ∑ Endosulfan (α -, β -, and -sulfate) 0.082 ng/ml > DDT and derivatives 0.019 ng/ml > ∑ HCH (α -, γ -, β -, and δ -HCH) 0.014 ng/ml > aldrin and dieldrin 0.007 ng/ml > heptachlor and heptachlor epoxide 0.0068 ng/ml > endrin and endrin aldehyde 0.005 ng/ml > methoxychlor 0.001 ng/ml, respectively. Using the worst-case scenario defined as the reasonable maximum exposure (RME) to assess the potential cancer risk, five OCPs (dieldrin, 4,4′ -DDT, β -HCH, heptachlor, and heptachlor epoxide) may pose a risk of concern on a lifetime human carcinogenesis greater than one in a million.