Significance of Population Centers As Sources of Gaseous and Dissolved PAHs in the Lower Great Lakes

Authors

Carie A. McDonough
Mohammed A. Khairy
Derek C G Muir
Rainer Lohmann, University of Rhode IslandFollow

Document Type

Article

Date of Original Version

2014

Department

Oceanography

Abstract

Polyethylene passive samplers (PEs) were used to measure concentrations of gaseous and dissolved polycyclic aromatic hydrocarbons (PAHs) in the air and water throughout the lower Great Lakesduring summer and fall of 2011. Atmospheric Σ_15PAH­ concentrations ranged from 2.1 ng/m³ in Cape Vincent (NY) to 76.4 ng/m³ in downtown Cleveland (OH). Aqueous Σ_18PAH concentrations ranged from 2.4 ng/L at an offshoreLake Erie site to 30.4 ng/L in Sheffield Lake (OH). Gaseous PAH concentrations correlated strongly with population within 3-40 km of the sampling site depending on the compound considered, suggesting that urban centers are a primary source of gaseous PAHs (except retene) in the lowerGreat Lakes region. The significance of distant population (within 20 km) versus local population (within 3 km) increased with sub-cooled liquid vapor pressure. Most dissolved aqueous PAHs did not correlate significantly with population, nor were they consistently related to river discharge, wastewater effluents, or precipitation. Air-water exchange calculations implied that diffusive exchange was a source of phenanthrene to surface waters, while acenaphthylene volatilized out of the lakes. Comparison of air-water fluxes with temperature suggested that the significance of urban centers as sources of dissolved PAHs via diffusive exchange may decrease in warmer months.

Citation/Publisher Attribution

McDonough, C. A., Khairy, M A., Muir, D. C. G., & Lohmann, R. (2014). Significance of population centers as sources of gaseous and dissolved PAHs in the lower Great Lakes. Environmental Science & Technology, 48(14), 7789-7797. doi: 10.1021/es501074r

Available at: http://dx.doi.org/10.1021/es501074r