Wang Magnus, Rautmann Dirk
RIFCon, Im Neuenheimer Feld 517, 69120 Heidelberg, Germany.
Environ Toxicol Chem. 2008 Dec;27(12):2617-26. doi: 10.1897/08-109.1.
Spray drift represents a major mode of exposure in off-crop habitats or surface waters after pesticide spray application. Currently, the estimation of exposure by spray drift is based on a deterministic estimation of the amount of drifting residues, either with the use of default drift values or deterministic models, which, however, do not reproduce the entire range of spray drift observed in reality. However, because a series of data from extensive field trials are available, probabilistic methods based on Monte Carlo simulation can reveal realistic estimates of the entire range of exposures. For the development of a probabilistic spray drift model, previously published data from a series of field trials was analyzed to reveal how these data could be used for the parameterization of a probabilistic model. This analysis showed that wind speed, agricultural equipment (nozzle type, spray pressure), and relative humidity showed the strongest effect on spray drift. But remarkably, the effect differed for different distances from sprayed fields. For example, higher wind speed increased spray drift only at larger distances while it even reduced spray drift very close to field borders. Also spray pressure influenced spray drift predominantly close to fields. After identifying the parameters with the strongest effects, a probabilistic model for the estimation of the exposure by spray drift in off-crop habitats was developed. Spray drift can be simulated for any given distance from fields. It is demonstrated how the exposure and the amount of effects can be estimated when applying this model in real landscapes. Results are compared with a deterministic risk assessment.
喷雾漂移是农药喷施后在非作物生境或地表水暴露的主要途径。目前，通过喷雾漂移进行暴露估计是基于对漂移残留量的确定性估计，要么使用默认漂移值，要么使用确定性模型，但这些方法无法再现实际观察到的整个喷雾漂移范围。然而，由于有一系列来自广泛田间试验的数据，基于蒙特卡洛模拟的概率方法可以揭示整个暴露范围的实际估计值。为了开发概率喷雾漂移模型，对先前发表的一系列田间试验数据进行了分析，以揭示如何将这些数据用于概率模型的参数化。该分析表明，风速、农业设备（喷嘴类型、喷雾压力）和相对湿度对喷雾漂移的影响最为显著。但值得注意的是，不同距离喷施田块的影响有所不同。例如，较高的风速仅在较大距离处增加喷雾漂移，而在非常靠近田边时甚至会减少喷雾漂移。喷雾压力也主要在靠近田块处影响喷雾漂移。在确定了影响最强的参数后，开发了一个用于估计非作物生境中喷雾漂移暴露的概率模型。可以针对距田块的任何给定距离模拟喷雾漂移。展示了在实际景观中应用该模型时如何估计暴露和影响程度。将结果与确定性风险评估进行了比较。
