title: Processing of atmospheric polycyclic aromatic hydrocarbons by fog in an urban environment.
abstract: Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants in the atmosphere, predominantly known for their toxicity. Although there has been substantial work on the atmospheric degradation of PAH, little is known about how the presence of atmospheric droplets (e.g., a fog cloud) affects the fate of PAH. In order to assess the processing of PAH and their corresponding oxidation products during a fog event, two field-sampling campaigns in Fresno, CA and Davis, CA were conducted. The simultaneous evaluation of concentrations of the PAH and oxygenated polycyclic aromatic compounds (OPAC) in the gas phase, particulate matter and fog water droplets before, during and after fog allows for the characterization of transformative and transport processes in a fog cloud. By tracking the ratio of OPAC to PAH in the individual atmospheric phases, two major polycyclic aromatic compounds-processing pathways can be identified: (i) the dissolution of OPAC from particulate matter and (ii) the uptake and oxidation of PAH in the fog water droplets. Wet deposition steadily decreases the pollutant concentration in the fog cloud droplets during a fog event; however, uptake and concentration via evaporative water loss upon the dissipation of a fog cloud cause an increase in the atmospheric pollutant concentration.
authors.affiliation: Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Franz S
authors.initials: FS
authors.lastname: Ehrenhauser
authors.forename: Kalindi
authors.initials: K
authors.lastname: Khadapkar
authors.forename: Youliang
authors.initials: Y
authors.lastname: Wang
authors.forename: James W
authors.initials: JW
authors.lastname: Hutchings
authors.forename: Olivier
authors.initials: O
authors.lastname: Delhomme
authors.forename: Raghava R
authors.initials: RR
authors.lastname: Kommalapati
authors.forename: Pierre
authors.initials: P
authors.lastname: Herckes
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Wornat
authors.forename: Kalliat T
authors.initials: KT
authors.lastname: Valsaraj
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D001272:Atmosphere / Q000737:chemistry*; D002140:California; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D014887:Weather
chemical_list: D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons