Pesticides in the atmosphere: a comparison of gas-particle partitioning and particle size distribution of legacy and current-use pesticides

摘要

This study presents a comparison of seasonal variation, gas-particlepartitioning, and particle-phase size distribution of organochlorinepesticides (OCPs) and current-use pesticides (CUPs) in air. Two years(2012/2013) of weekly air samples were collected at a background site in theCzech Republic using a high-volume air sampler. To study the particle-phasesize distribution, air samples were also collected at an urban and rural sitein the area of Brno, Czech Republic, using a cascade impactor separatingatmospheric particulates according to six size fractions. Major differenceswere found in the atmospheric distribution of OCPs and CUPs. The atmosphericconcentrations of CUPs were driven by agricultural activities while secondarysources such as volatilization from surfaces governed the atmosphericconcentrations of OCPs. Moreover, clear differences were observed ingas-particle partitioning; CUP partitioning was influenced by adsorption ontomineral surfaces while OCPs were mainly partitioning to aerosols throughabsorption. A predictive method for estimating the gas-particle partitioninghas been derived and is proposed for polar and non-polar pesticides. Finally,while OCPs and the majority of CUPs were largely found on fine particles,four CUPs (carbendazim, isoproturon, prochloraz, and terbuthylazine) hadhigher concentrations on coarse particles (   3.0 µm), which maybe related to the pesticide application technique. This finding isparticularly important and should be further investigated given that largeparticles result in lower risks from inhalation (regardless the toxicity ofthe pesticide) and lower potential for long-range atmospheric transport.