Beach J R, Spurgeon A, Stephens R, Heafield T, Calvert I A, Levy L S, Harrington J M
Institute of Occupational Health, University of Birmingham.
Occup Environ Med. 1996 Aug;53(8):520-5. doi: 10.1136/oem.53.8.520.
Organophosphates are effective pesticides which are frequently used in several agricultural settings. Although their acute effects are well characterised, it remains unclear whether long term exposure can damage the human nervous system. This study sought to investigate their long term effects by comparing abnormalities on neurological examination between groups of workers exposed to organophosphates and an unexposed group.
146 exposed sheep farmers and 143 unexposed quarry workers were recruited into a cross sectional study of symptoms and neuropsychological effects of long term exposure to organophosphates in sheep dip. From a symptom questionnaire given immediately after dipping the 10 most symptomatic and 10 least symptomatic farmers were selected. Several months later each of these, along with 10 of the unexposed quarry workers, underwent a standardised neurological examination similar to that which might be used in clinical practice, at at time as remote as possible from recent exposure to organophosphates so as to exclude any acute effects.
All 30 selected subjects agreed to participate. The components of the examination which showed a significant difference were two point discrimination on the dorsum of the hand (symptomatic farmers 22 mm; asymptomatic farmers 13 mm; quarry workers 8 mm) and the dorsum of the foot (symptomatic farmers 34 mm; asymptomatic farmers 10 mm; quarry workers 11 mm), and mean calf circumference (symptomatic farmers 35.0 cm; asymptomatic farmers 36.3 cm; quarry workers 38.6 cm). Overall the prevalence of neurological abnormalities was low.
The differences in neurological examination detected between groups were subtle and their clinical significance was unclear. However, they do suggest evidence of an adverse neurological effect from exposure to organophosphates. Further, larger scale studies will be required before it is possible to confirm or refute the differences detected.
有机磷酸酯是有效的杀虫剂，常用于多种农业环境。尽管其急性效应已得到充分表征，但长期接触是否会损害人类神经系统仍不清楚。本研究旨在通过比较接触有机磷酸酯的工人组和未接触组之间神经学检查的异常情况，来调查其长期影响。
146名接触有机磷酸酯的养羊农民和143名未接触的采石场工人被纳入一项关于长期接触羊药浴中有机磷酸酯的症状和神经心理效应的横断面研究。在药浴后立即发放症状问卷，从中选出症状最明显的10名农民和症状最不明显的10名农民。几个月后，这些农民以及10名未接触的采石场工人接受了类似于临床实践中使用的标准化神经学检查，检查时间尽可能远离最近接触有机磷酸酯的时间，以排除任何急性效应。
所有30名选定的受试者均同意参与。检查中显示出显著差异的部分包括手背两点辨别觉（症状明显的农民为22毫米；无症状的农民为13毫米；采石场工人为8毫米）和脚背两点辨别觉（症状明显的农民为34毫米；无症状的农民为10毫米；采石场工人为11毫米），以及小腿平均周长（症状明显的农民为35.0厘米；无症状的农民为36.3厘米；采石场工人为38.6厘米）。总体而言，神经学异常的患病率较低。
各组之间在神经学检查中检测到的差异很细微，其临床意义尚不清楚。然而，它们确实表明有证据显示接触有机磷酸酯会产生不良神经学影响。此外，在能够证实或反驳所检测到的差异之前，还需要进行更大规模的研究。
