Hematological indices of pesticide exposure on rice farmers in Southern Thailand

Abstract

The most common pesticides used in rice farming are organophosphates and carbamates. These pesticides inhibit acetylcholinesterase (AChE) activity, resulting in excessive levels of acetylcholine accumulation and disrupted neurotransmission. This study compared AChE activity and hematological parameters between pesticide-using rice farmers, non-pesticide-using rice farmers, and non-agricultural occupational groups (non-farmers). Pesticide residues that accumulated in the rice, water, and soil of the study area were also determined. AChE activity of all participants showed 10 out of 87 samples (11.49%) as borderline depressed, with 50% of those being pesticide-using farmers. Most of the hematological parameters were normal in all samples. However, platelet numbers of self-spraying pesticide rice farmers were significantly lower than those of non-self-spraying rice farmers. The results suggested that the use of pes ticides during rice farming affected AChE activity and some hematological cells. Besides, pesticide residues in soil, water, and rice in the fields using pesticides were higher than in non-pesticide use areas. Results confirmed that the farmers using pesticides experienced higher exposure rates than farmers who did not use pesticides.