Polycyclic Aromatic Hydrocarbon Contamination in South Carolina Salt Marsh-Tidal Creek Systems: Relationships Among Sediments, Biota, and Watershed Land Use

Sediments and biota from 11 tidal creeks were sampled and classified into forested, suburban, and urban/industrial watershed land-use categories. Total PAH levels ([summation operator]PAH₁₆) in sediments were significantly higher in urban/industrialized creeks (5,795 ± 1,173 ng/g) compared to suburban (793 ± 131 ng/g) and forested (238 ± 34 ng/g) creeks. No differences in [summation operator]PAH₁₆ levels among land-use classifications were found for either oligochaetes (Monopylephorus rubroniveus) or grass shrimp (Palaemonetes pugio). However, [summation operator]PAH₁₆ levels in grass shrimp were related to sediment [summation operator]PAH₁₆ levels and [summation operator]PAH₁₆ levels in oligochaetes and grass shrimp eggs were related to impervious cover in the watershed. Diagnostic ratios suggest that the primary sources of PAH in suburban and urban/industrialized creeks are pyrogenic. Carcinogenic PAH contents of sediments and biota were related to impervious cover. While human exposures to these sediment-associated carcinogens were not assessed, levels of several carcinogenic PAHs in sediments of urban/industrial tidal creeks were above the levels that represent an increased cancer risk in humans.