Centre for Environment and Population Health, Griffith School of Environment, Griffith University, 170 Kessels Road, Nathan, QLD, 4111, Australia.
Department of Environmental Science, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Environ Sci Pollut Res Int. 2018 Jul;25(21):20854-20867. doi: 10.1007/s11356-018-2259-9. Epub 2018 May 15.
Chlorpyrifos is a neurotoxic insecticide that is widely used in the agricultural sector of Ghana. The main objective of this study was to evaluate the levels of chlorpyrifos exposure and health risk among applicators (n = 21) on irrigated rice farms in Ghana, based on a typical application event. Pre- and post-application urine samples (24-h) were collected from the applicators and analysed for 3,5,6-trichloro-2-pyridinol (TCP), using LC-MS/MS. The levels of chlorpyrifos-absorbed dose with the applicators were estimated from the urinary TCP levels. Prior to application, the median absorbed dose of chlorpyrifos (background exposure) with the applicators was 0.2 μg/kg/day (range 0.05 to 2 μg/kg/day). Following application, the median absorbed dose of chlorpyrifos (application exposure) increased 30-fold to 6 μg/kg/day (range 0.7 to 74 μg/kg/day). The mean elimination half-life (t) of chlorpyrifos was calculated to be 50 h. Hazard quotient (HQ) values (HQ > 1) obtained with the chronic (10 μg/kg/day) and acute (100 μg/kg/day) guideline values of the WHO suggested no risk of chronic or acute health effects, respectively, among both the median and 5% highly exposed groups. However, HQ values (HQ > 1) obtained with the chronic (0.3 μg/kg/day) and acute (5 μg/kg/day) guideline values of the USEPA suggested risk of chronic and acute health effects, respectively, among both the median and 5% highly exposed groups. The quantity of chlorpyrifos formulation applied, spraying duration, and the number of spray tanks applied significantly correlated with the absorbed dose levels of chlorpyrifos from application exposure. Therefore, these factors suggest means to reduce exposure and consequent health risk among the applicators.
毒死蜱是一种广泛应用于加纳农业部门的神经毒杀虫剂。本研究的主要目的是评估加纳灌溉水稻农场中施药者（n=21）在典型施药事件中接触毒死蜱的水平和健康风险。在施药前后，采集施药者的 24 小时尿液样本，使用 LC-MS/MS 分析 3、5、6-三氯-2-吡啶醇（TCP）的水平。通过尿 TCP 水平估算施药者吸收的毒死蜱剂量。施药前，施药者吸收的毒死蜱（背景暴露）中位数剂量为 0.2μg/kg/天（范围 0.05-2μg/kg/天）。施药后，施药者吸收的毒死蜱（施药暴露）中位数剂量增加了 30 倍，达到 6μg/kg/天（范围 0.7-74μg/kg/天）。毒死蜱的平均消除半衰期（t）计算为 50 小时。根据世界卫生组织（WHO）的慢性（10μg/kg/天）和急性（100μg/kg/天）指导值，获得的危害商（HQ）值（HQ>1）分别表明，在中值和 5%高暴露组中，均无慢性或急性健康影响的风险。然而，根据美国环保署（USEPA）的慢性（0.3μg/kg/天）和急性（5μg/kg/天）指导值，获得的 HQ 值（HQ>1）表明，在中值和 5%高暴露组中，均存在慢性和急性健康影响的风险。施药时使用的毒死蜱制剂的数量、喷雾持续时间和应用的喷雾罐数量与施药暴露中吸收的毒死蜱剂量水平显著相关。因此，这些因素提示可以采取措施减少施药者的接触和随之而来的健康风险。
