Low-level exposure to organophosphate pesticides leads to restrictive lung dysfunction.

Apart from symptomology, there are very few reports on lung function following exposure to low levels of organophosphate (OP) pesticides in man. Twenty-five occupationally exposed farmers and 22 environmentally exposed freshwater fishermen were evaluated between and during OP spray seasons. Forty marine fishermen living away from agricultural areas were recruited as a control group. Forced vital capacity (FVC) and forced expiratory volume in the first second (FEV(1)) were measured by spirometry. Haemoglobin corrected erythrocyte acetylcholinesterase (AChE) levels were measured during and between (baseline estimation) spray seasons using a portable WHO-approved Test-mate system (EQM Research, Ohio). FVC ratio was lower in the farmers as compared to the controls (P<0.001) between exposure seasons. In the farmers, FVC ratio decreased further during the exposure season (P=0.023). FEV(1) was lower in the farmers as compared to the controls in both periods (P<0.05). In the fishermen, the decrease in ratios of FVC and FEV(1) following exposure to pesticides was not significant. FEV(1)/FVC ratios were similar in the three groups between (P=0.988) and during (P=0.159) exposure periods. Following exposure to OPs, AChE levels dropped 12.75% in the farmers (P<0.001) and 5.62% in the freshwater fishermen (P=0.001). Occupational exposure to OP results in restrictive lung dysfunction, a phenomenon not observed following environmental exposure.

Effects of occupational exposure to organophosphate pesticides on nerve and neuromuscular function.

This study aimed to investigate whether occupational exposure to organophosphate (OP) pesticides caused neurophysiological abnormalities. Thirty farmers who regularly spray OP pesticides and 30 fishermen (controls), living close by but not involved in pesticide spraying, were evaluated during and between cultivation seasons. The farmers had higher erythrocyte acetylcholinesterase levels than the controls during (P = 0.06) and between cultivation seasons (P = 0.09). During the cultivation season, there was a significant reduction in erythrocyte acetylcholinesterase activity in both groups (P < 0.01). Significant differences between the farmers and controls were found in sensory conduction velocity (P = 0.04) and motor conduction velocity (P = 0.04) between cultivation seasons. Sensory conduction velocity was reduced significantly in farmers (P < 0.01) and in controls (P = 0.04) during the cultivation season. Effects of OP poisoning were seen both in farmers and in controls, who had no history of spray activities. Evidence of sensory dysfunction after acute exposure and sensory and motor impairment after long-term low-level exposure to OP was seen.