Human health risk assessment related to dermal exposure of chlorpyrifos in rice-growing farmers at Nakhon Nayok Province, Thailand

Abstract

Rice-growing farmers in SisaKrabue sub-district, Ongkharak district, NakhonNayok province, Thailand was studied health risk assessment of chlorpyrifos exposure through dermal route. This study had 35 participants who related with pesticide application and most of them were male. In this study used fluorescent tracer to reveal pesticide contaminated on body skin. The result showed the frequency of fluorescent tracer was largely found on lower (97.14%) and upper legs (97.14%)of farmers and rarely found on their chest under clothes (45.71%) and the greatest number of percent fluorescent scoring was lower (72.38%) and upper legs (62.86%) and the smallest percent of fluorescent scoring was chest under clothes (19.05%) that was same as percent frequency of pesticide residues on seven parts of farmers' body. The farmers were patched with cotton gauze on seven points of farmers’ body. Both of male and female lower leg were the part of body where was the highest concentration of chlorpyrifos (261.64 and 164.64 mg/kg of gauze, orderly). The comparison of chlorpyrifos concentration on seven parts of body between male and female,There was not a statistical difference (Mann-Whitney U test; p>0.05). Moreover, There was significantly correlation between chlorpyrifos residues concentration and fluorescent scoring on chest on clothes, chest under clothes, upper leg, lower leg, and whole body (Spearman’s rho; p<0.05). ADD on seven parts of male and female farmers were31.72x10-4, 193.32x10-4, 5.38x10-4, 190.48x10-4, 170.47x10-4, 465.91x10-4, and 43.04x10-4mg/kg-day, orderly. Hazard Quotient (HQ) at mean and 95th percentile level on seven parts of body of both male and female was greater than acceptable level (HQ >1). This can be interpreted that rice-growing farmers in this area received adverse health risk from skin exposure to chlorpyrifos. In conclusion, safety risk management in term of pesticide use and practices should be conducted in SisaKrabue area to minimize exposure from chlorpyrifos usage via dermal route.