Oriel Michel, Edmiston Susan, Beauvais Sheryl, Barry Terrell, O'Malley Michael
Occupational Health Services, University of California, Davis, Davis, CA, USA.
Rev Environ Contam Toxicol. 2009;200:1-31. doi: 10.1007/978-1-4419-0028-9_1.
With limitations imposed on the use of methyl bromide by international treaty, use of metam-sodium, chloropicrin, and other fumigants have increased; this increase has been accompanied by multiple community illness episodes. In this review we address the California experience of direct or indirect exposures to chloropicrin, after use of this fumigant as an active ingredient in agricultural pest control, from the years 1992-2003. The best available toxicology data demonstrate that, for brief exposures (5-30 sec), eye irritation (or at least "chemesthesis"--detection of exposure by the eye) occurred in 50% of volunteer subjects exposed to 700 ppb of chloropicrin. Of 62 subjects tested, 10-15% (depending upon the site of exposure) failed to detect 1200 ppb of chloropicrin (the highest concentrations tested). For exposures lasting 20 min, the minimum concentration detectable by 50% of the subjects was 75 ppb; the no-observed-effect-level (NOEL) for eye irritation was 50 ppb. Exposures for 1 hr, at 100 and 150 ppb, produced subjective eye irritation in most subjects. Using a standard tenfold uncertainty factor (Extoxnet 2006), an estimated NOEL for a 1-hr exposure to chloropicrin (calculated from the 100 ppb lowest-observed-effect-level) would be 10 ppb. The few monitoring studies conducted for agricultural use of chloropicrin demonstrate that the most sensitive effect to chloropicrin exposure is sensory irritation. The use of chloropicrin for field fumigation presents a difficult problem, both because of the extreme degree to which it is irritating, and because of the very low concentrations that cause such irritation. The cases summarized in this report, especially those resulting from applications that adhere to label and permit standards, suggest that additional mitigation measures are needed to minimize off-site human exposure associated with chloropicrin applications in California. Examination of the previously discussed Pesticide Illness Surveillance Program cases revealed that conducting the applications according to label directions and local permit conditions was not always adequate to prevent off-site exposure or resultant irritation or other symptoms. This suggests that current methods of fumigant containment and/or buffer zone requirements are insufficient under some circumstances.
随着国际条约对甲基溴使用的限制，威百亩、氯化苦及其他熏蒸剂的使用量有所增加；这种增加伴随着多起社区疾病事件。在本综述中，我们阐述了1992年至2003年期间在加利福尼亚州，将氯化苦作为农业害虫防治的活性成分使用后，直接或间接接触氯化苦的情况。现有的最佳毒理学数据表明，对于短暂暴露（5 - 30秒），暴露于700 ppb氯化苦的志愿者中，有50%出现眼部刺激（或至少是“化学感觉”——眼睛检测到暴露）。在62名受试对象中，10 - 15%（取决于暴露部位）未能检测到1200 ppb的氯化苦（测试的最高浓度）。对于持续20分钟的暴露，50%的受试者能够检测到的最低浓度为75 ppb；眼部刺激的未观察到效应水平（NOEL）为50 ppb。在100和150 ppb浓度下暴露1小时，大多数受试者出现了主观眼部刺激。使用标准的十倍不确定性系数（Extoxnet 2006），估计1小时暴露于氯化苦的NOEL（根据100 ppb的最低观察到效应水平计算）为10 ppb。针对氯化苦在农业上的使用所进行的少数监测研究表明，对氯化苦暴露最敏感的效应是感觉刺激。由于氯化苦的刺激性极强，且引起这种刺激的浓度极低，因此将其用于田间熏蒸带来了一个难题。本报告总结的案例，尤其是那些符合标签和许可标准的施用所导致的案例，表明需要采取额外的缓解措施，以尽量减少加利福尼亚州与氯化苦施用相关的场外人员暴露。对先前讨论的农药疾病监测计划案例的审查表明，按照标签说明和当地许可条件进行施用并不总是足以防止场外暴露或由此产生的刺激或其他症状。这表明，在某些情况下，当前熏蒸剂的 containment 和/或缓冲区要求方法并不充分。 （注：containment 此处可能是指“控制措施”之类含义，原文可能拼写有误，推测可能是“containment measures”，但按照要求未做修改直接翻译）
