Pollution Research Paper

Vol 39, Issue 4, 2020; Page No.(879-885)

PESTICIDE EXPOSURE OF RICE FARMERS AND HERBICIDE RESIDUE IN PADDY FIELD, SUPHAN BURI, THAILAND

K. SUWANNAHONG, A. SRIDON, T. PITAKSILP, W. PONGSTAPORN AND Y. SUDJAROEN

Abstract

Suphanburi is rice cultivation area for two or three growing cycles. Agropesticide application is on intensively cultivated rice crop land when water conditions allow had occurred. This study was aimed to evaluate serum cholinesterase (SChE) and associated risk factors of pesticides exposure; and to determine paraquat and glyphosate in soil, water supply and harvesting rice samples as environmental residues. Gathered information concerning of long-term pesticide exposures from 50 rice farmers and 50 control respondents was conducted by questionnaire interviewing and SChE screening. Risky and unsafe rice farmers were confirmed for SChE level by automatic analyzer. The paraquat and glyphosate levels in environmental samples were analyzed by liquid chromatography- mass spectrometry/ mass spectrometry (LC-MS/MS). Rice farmers were long-term pesticide exposure over 10 years. Serum cholinesterase level was not significantly different between farmer and control group (p = 0.033). Pesticides relating symptoms were rarely observed and unexpected finding may due to unspecific symptoms, imprecisely explain and tolerance of frequently exposed farmers. Paraquat and glyphosate were detected from the soil (12/10), water (6/5) and rice (3/8) samples; however, the amount was lower than 0.05 mg/kg or mg/mL based on US EPA and FAO/WHO standard. Insignificant level of SChE in long-term exposure may lead to recommendation of biomarker measurements, such as, DAPs, 3-PBA and urinary glyphosate for evaluation of multiple pesticide use. Paraquat and glyphosate residues were within the acceptable range. Therefore, health and environmental effects of herbicide use were still concerned in rice farmers, passive exposures and consumers.