The aim of this study was to obtain a longitudinal evaluation of the exposure to chlorpyrifos (CP) and chlorpyrifos-methyl (CPM) in agricultural workers in South Tyrol and in a residential group living in the same area. CP and CPM are widely used pesticides in agriculture. Biological monitoring of CP and CPM exposure in humans can be achieved by analyzing urinary levels of 3,5,6-trichloro-2-pyridinol (TCPy). TCPy a metabolite of CP and CPM which is produced by a two-step metabolic transformation. Between May 14th, 2014 and March 16th, 2015 we conducted a longitudinal study on 28 farmers actively working in spray pesticide treatment and 43 non-farmers living in the same agricultural area of South Tyrol (Italy). Urine samples were collected at two time points: during the pesticide treatment period and in a temporally distant season that should guarantee metabolite clearance. We developed and validated a liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for the determination of urinary TCPy levels. During the treatment season, both farmers and residents showed higher TCPy levels (median = 6.8 and 6.73 ug/g creatinine, respectively) than during the non-treatment season (median = 2.54 and 3.22 ug/g creatinine, respectively), suggesting a similar effect of the pesticide spraying on both groups. However, the observed TCPy levels resulted in a daily CP and CPM intake well below the limits recommended by FAO/WHO. During the non-treatment season, non-farmers showed higher TCPy levels values than farmers, suggesting the existence of TCPy of other unmeasured sources of exposure not considered in this study. This suggests that, for a comprehensive evaluation of the risks associated with TCPy exposure, additional sources should be identified in addition to CP and CPM pesticides.

本研究的目的是对南蒂罗尔州的农业工人和居住在同一地区的居民组中的毒死蜱 (CP) 和甲基毒死蜱 (CPM) 进行纵向评估。CP和CPM是农业中广泛使用的农药。通过分析尿中 3,5,6-三氯-2-吡啶 (TCPy) 的水平，可以实现对人类 CP 和 CPM 暴露的生物监测。TCPy 是 CP 和 CPM 的代谢物，由两步代谢转化产生。2014 年 5 月 14 日至 2015 年 3 月 16 日期间，我们对生活在南蒂罗尔（意大利）同一农业区的 28 名积极从事喷洒农药处理的农民和 43 名非农民进行了纵向研究。在两个时间点收集尿液样本：在农药处理期间和应保证代谢物清除的时间遥远的季节。我们开发并验证了一种用于测定尿 TCPy 水平的液相色谱-串联质谱 (LC-MS/MS) 方法。在处理季节，农民和居民的 TCPy 水平（中位数分别为 6.8 和 6.73 ug/g 肌酐）高于非处理季节（中位数分别为 2.54 和 3.22 ug/g 肌酐），表明相似的喷洒农药对两组的影响。然而，观察到的 TCPy 水平导致每日 CP 和 CPM 摄入量远低于粮农组织/世卫组织建议的限值。在非处理季节，非农民的 TCPy 水平值高于农民，表明本研究中未考虑的其他未测量的暴露源的 TCPy 的存在。这表明，为了全面评估与 TCPy 暴露相关的风险，除了 CP 和 CPM 农药之外，还应确定其他来源。