Background concentrations of PAHs and metals in surface and subsurface soils collected throughout Manhattan, New York

This article summarizes the results from a survey of polycyclic aromatic hydrocarbon (PAH) and metal concentrations measured in surface and subsurface soil samples that were collected from background locations throughout Manhattan, New York, between August 2005 and May 2006. The 95th percentile total 16 US EPA Priority Pollutant PAH concentrations in surface and subsurface soils were 24.8 and 53.1 mg/kg, respectively. Diagnostic PAH source ratios for surface and subsurface soils are presented, which provide plausible bounds for where these ratios would and would not be able to confidently differentiate background soils from soil samples that are impacted by PAH contamination. The 95th percentile concentrations for lead in surface and subsurface soils were 891 and 2,540 mg/kg, respectively, and the 95th percentile concentrations for mercury in surface and subsurface soils were 1.9 and 2.7 mg/kg, respectively. A not-unexpected finding of the study was that most surface soils and all subsurface soils...