The distribution and sources of polycyclic aromatic hydrocarbons in Narragansett Bay surface sediments

Abstract

Polycyclic aromatic hydrocarbons (PAHs) were measured in 41 surface sediments from Narragansett Bay, RI. All the analytes generally decrease down bay from the Seekonk, Providence and Taunton Rivers at the head of the bay. Total PAHs ranged from 0.569 to 216 μg/g with 27% exceeding the effects range median (ERM) of 44.8 μg/g and 73% of the stations exceeding the effects range low (ERL) of 4.02 μg/g ( Long et al., 1995). Based on principal component analysis, the major source of the contaminants in Narragansett Bay was the Providence River while the coves and Taunton River/Mt. Hope Bay appeared to only have a limited influence on the open bay. PAH source ratios indicate that creosote and/or coal may be the most significant contributor of pyrogenic high molecular weight PAHs in Narragansett Bay, along with significant contributions from diesel exhaust.