Dalvie Mohamed A, London Leslie
Occupational and Environmental Health Research Unit, Department of Public Health, Medical School, University of Cape Town, Anzio Road, Observatory, 7925 Cape Town, South Africa.
Environ Res. 2006 Nov;102(3):326-32. doi: 10.1016/j.envres.2006.01.008. Epub 2006 Mar 23.
A cluster of Guillaine-Barre syndrome cases in the Vaalharts region, South Africa prompted an investigation of the impact of aerial organophosphate spraying on cholinesterase levels of residents in the region. A prospective study of cholinesterase levels among residents and workers in the area and a control area was performed. Standardized red blood cell cholinesterase levels amongst participants were monitored before (round 1), during (round 2), and after (round 3) the 1996/1997 aerial spraying season. Participants were assigned environmental exposure categories based on the time since (within 10 or 30 days) and distance from (on farm, on neighboring farm, <10 km from farm) aerial pesticide application. There were 342 participants in round 1, of whom 78% participated in round 2, 62% in round 3, and 56% in all three rounds. There was an increase in cholinesterase levels in round 2 (mean increase = 5.96+/-6.25 IU/g hemoglobin) and then a decrease in round 3 (6.17+/-6.51), significantly associated with environmental exposure (participants living on farm or neighboring farm and <10 km from spraying area) controlling for age, gender, alcohol dependence, and usual and recent domestic and occupational pesticide use (e.g., for round 2-round 1 cholinesterase differences, beta; (exposed group relative to unexposed)=5.72+/-1.21 IU/g hemoglobin, P = 0.000, R2 = 0.27, n = 171). The results show a shift in cholinesterase levels associated with residence in the spraying area, but in the direction opposite to that expected from the spraying of pesticides. Seasonal fluctuations in ambient temperature during the study may have influenced the results.
南非瓦尔哈茨地区出现的一组吉兰 - 巴雷综合征病例促使人们对空中喷洒有机磷酸酯对该地区居民胆碱酯酶水平的影响展开调查。对该地区及一个对照地区的居民和工人的胆碱酯酶水平进行了一项前瞻性研究。在1996/1997年空中喷洒季节之前（第1轮）、期间（第2轮）和之后（第3轮）监测了参与者的标准化红细胞胆碱酯酶水平。根据自空中喷洒农药以来的时间（10天或30天内）以及与喷洒地点的距离（在农场、在相邻农场、距农场<10公里）为参与者划分环境暴露类别。第1轮有342名参与者，其中78%参与了第2轮，62%参与了第3轮，56%参与了所有三轮。第2轮胆碱酯酶水平有所上升（平均升高 = 5.96±6.25 IU/g血红蛋白），然后在第3轮下降（6.17±6.51），在控制了年龄、性别、酒精依赖以及日常和近期家庭及职业农药使用情况后，与环境暴露显著相关（居住在农场或相邻农场且距喷洒区域<10公里的参与者）（例如，对于第2轮 - 第1轮胆碱酯酶差异，β（暴露组相对于未暴露组）= 5.72±1.21 IU/g血红蛋白，P = 0.000，R2 = 0.27，n = 171）。结果显示，胆碱酯酶水平的变化与居住在喷洒区域有关，但方向与农药喷洒预期的相反。研究期间环境温度的季节性波动可能影响了结果。
