Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
Environ Sci Process Impacts. 2015 Jul;17(7):1228-37. doi: 10.1039/c5em00122f.
The main objective of this study was to evaluate the performance of a model for simulating the uptake of various pesticides on passive air samplers (PAS). From 2006-2007 a series of PAS using XAD-resin were deployed at Egbert, a rural agricultural site in southern Ontario, Canada, to measure the uptake of pesticides for time periods ranging from two months to one year. A continuous increase in sequestered amounts was observed for most pesticides, except for trifluralin and pendimethalin, which could conceivably be subject to substantial degradation inside the sampler. Continuous low-volume active air samples taken during the same period, along with data on weather conditions, allowed for the simulation of the uptake of the pesticides using the model (PAS-SIM). The modelled accumulation of pesticides on the PAS over the deployment period was in good agreement with the experimental data in most cases (i.e., within a factor of two) providing insight into the uptake kinetics of this type of sampler in the field. Passive sampling rates (PSR, m(3) d(-1)) were determined from the empirical data generated for this study using three different methods and compared with the PSRs generated by the model. Overall, the PAS-SIM model, which is capable of accounting for the influence of temperature and wind variations on PSRs, provided reasonable results that range between the three empirical approaches employed and well-established literature values. Further evaluation and application of the PAS-SIM model to explore the potential spatial and temporal variability in PAS uptake kinetics is warranted, particularly for established monitoring sites where detailed meteorological data are more likely to be available.
本研究的主要目的是评估一个模型模拟各种农药在被动空气采样器（PAS）上的吸收性能。2006-2007 年，在加拿大安大略省南部的一个农村农业点 Egbert，使用 XAD-树脂的一系列 PAS 被部署用于测量农药的吸收时间范围从两个月到一年。除了氟乐灵和二甲戊灵外，大多数农药的被隔离量都在持续增加，这两种农药在采样器内可能会发生大量降解。在同一时期连续采集的低体积主动空气样本，以及有关天气条件的数据，允许使用该模型（PAS-SIM）模拟农药的吸收。在大多数情况下，模型模拟的 PAS 上农药积累在部署期间与实验数据非常吻合（即，在两倍以内），从而深入了解了这种采样器在现场的吸收动力学。通过本研究生成的经验数据，使用三种不同的方法确定了被动采样速率（PSR，m3 d-1），并将其与模型生成的 PSR 进行了比较。总体而言，PAS-SIM 模型能够考虑到温度和风速变化对 PSR 的影响，提供了介于三种经验方法和既定文献值之间的合理结果。进一步评估和应用 PAS-SIM 模型来探索 PAS 吸收动力学的潜在空间和时间变异性是必要的，特别是对于那些更有可能获得详细气象数据的已建立监测站点。
