PON1 Q192R Gene Polymorphism and Pesticide Exposure Status of Rice Farmers, Suphan Buri, Thailand

PON1 Q192R (rs662) polymorphism in coding region is conveying differential catalytic activity oforganophosphate. Study was aimed to investigate PON1 Q192R gene polymorphisms in rice farmers alongwith pesticide knowledge and practices; and to evaluate the relationship of gene polymorphisms and serumcholinesterase (SChE) levels. Information of pesticide exposure, knowledge and practices were collectedfrom 50 rice farmers and 50 control respondents by questionnaire interviewing. Each blood sample wasobtained by venipuncture and prepared to serum for SChE activity test by paper test and automatic analyzer;to EDTA blood for genotyping by PCR-RFLP. Exposure status, knowledge and practices on pesticide usewere represented as frequency. Chi-square was used to analyze on the different of personal information;and of polymorphism. Independent t-test was used for comparison of SChE levels. Person correlation wasevaluated relationship between SChE level and genotypes. 60% of rice farmers were used pesticide over10 years. Rice farmers were long-term pesticide exposure with good on pesticide knowledge, howeverpoorly practice. Means of SChE level of both groups were within reference value and significantly different(p = 0.033). Polymorphisms were included wild type (QQ), heterozygote (QR) and homozygote (RR);and were significantly different between rice farmers (high frequency of RR genotype) and control (p =0.02). Relationship of polymorphism and SChE level were negative correlated (r = -0.261; p = 0.031). Thispolymorphism may useful biomarker for chronic pesticide exposure in Thai rice farmer and corresponded todecline of serum cholinesterase; and RR genotype was high risk group.