Pesticide spray drift is potentially a significant source of exposure to off‐target, adjacent aquatic habitats. To estimate the magnitude of pesticide drift from aerial or ground applications, regulatory agencies in North America, Europe, and elsewhere rely on spray drift models to predict spray drift deposition for risk assessments. Refined assessments should ultimately depend on best‐available data for exposure modeling. However, when developing lower tier “screening” assessments designed to indicate whether further refinement is needed, regulators often make conservative assumptions with a resulting increased level of uncertainty in estimating environmental exposure or risk. In the United States, it is generally accepted that, to ensure conservative regulatory assessments, it is reasonable to assume that the wind speed might be 4.47 m/s (10 miles per hour [mph]), the relative humidity and temperature are highly conducive to drift, and the wind is blowing directly toward a receiving water for any given single spray event in a season. However, what is the probability these conditions will all co‐occur for each of 4 sequential spray events spaced a week apart (common practice for insecticides)? The refined approach in the present study investigates this question using hourly meteorological data sets for 5 United States Environmental Protection Agency (USEPA) standard crop scenarios to understand how real‐world data can reduce unnecessary uncertainty for sequential applications. The impact of wind speeds, temperatures, relative humidity, and wind direction at different times of day on annual drift loadings has been examined using a stepwise process for comparison with corresponding regulatory default loading estimates. The impacts on drift estimates were significant; interestingly, the time of day of the applications impacted variability more than did the selected crop scenario. When all these real‐world factors were considered, estimated 30‐y total drift loads ranged from 2% to 5% greater than the default estimate (2 of 30 cases due to high afternoon wind speeds) to 51% to 86% reductions (25 of 30 cases) with an overall average reduction of 63%. Integr Environ Assess Manag 2020;16:197–210. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

中文翻译：

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风速和风向以及关键气象参数对顺序航空应用中潜在的农药漂移质量负荷的影响。

农药喷雾漂移可能是远离目标，临近水生生境的重要暴露源。为了估算空中或地面应用中农药漂移的程度，北美，欧洲和其他地区的监管机构依靠喷雾漂移模型来预测喷雾漂移的沉积量，以进行风险评估。完善的评估最终应取决于暴露模型的最佳可用数据。但是，在制定旨在指示是否需要进一步完善的较低层“筛选”评估时，监管机构通常会做出保守的假设，从而导致环境暴露或风险估算的不确定性增加。在美国，为了确保进行保守的监管评估，通常认为风速可能为4是合理的。47 m / s（每小时10英里/小时[mph]）的相对湿度和温度非常有利于漂移，并且在一个季节中，对于任何给定的单次喷雾事件，风都直接吹向接收水。但是，在间隔一周的四个连续喷洒事件中，每一次都将同时发生这些情况的可能性（杀虫剂的常见做法）？本研究中的改进方法使用每小时气象数据集针对5个美国环境保护局（USEPA）标准作物情景调查此问题，以了解现实世界的数据如何减少连续应用的不必要不确定性。风速，温度，相对湿度，已使用逐步过程检查了年度漂移负荷在一天中不同时间的风向和风向，以与相应的监管默认负荷估算进行比较。对漂移估计的影响很大；有趣的是，与所选作物情景相比，一天中的应用时间对变异性的影响更大。考虑所有这些现实因素后，估计的30年总漂移负荷比默认估计值大2％至5％（30个案例中有2个由于午后风速高）至51％至86％的降低（25 30例），总体平均减少了63％。Integr环境评估管理2020； 16：197-210。©2019作者。Wiley Periodicals，Inc.代表环境毒理化学协会（SETAC）发行的《综合环境评估与管理》