Comparative Evaluation of Background Anthropogenic Hydrocarbons in Surficial Sediments from Nine Urban Waterways
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- 作者：Scott A. Stout ; Allen D. Uhler ; and Stephen D. Emsbo-Mattingly
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：June 1, 2004
- 年：2004
- 卷：38
- 期：11
- 页码：2987 - 2994
- 全文大小：264K
- 年卷期：v.38,no.11(June 1, 2004)
- ISSN：1520-5851
文摘
Anthropogenic hydrocarbons in surficial urban sedimentsderived from nonpoint sources (e.g., stormwater runoff,surface runoff, direct atmospheric deposition, and small butpersistent discharges) are the principal characteristicsof "urban background". Establishing the character andconcentration of urban background helps determine theincremental impacts from point sources and developsuccessful remedial strategies. In this study, we comparedthe nature and amount of total extractable hydrocarbons(THC) and polycyclic aromatic hydrocarbons (PAHs), includingalkylated PAHs, within 280 surficial (mostly 0-10 cm)sediments from nine, well-studied urban waterways onthe East and West U.S. Coasts. These 280 sediments werepredominantly impacted by urban background. All thesediments were analyzed by consistent preparation andanalytical methods and met consistent data quality objectives,thereby minimizing variations attributable to methodology.The data demonstrate that the anthropogenic hydrocarbonscomprising urban background from all locations exhibit agenerally consistent nature, dominated by (1) a variably shapedunresolved complex mixture (UCM) within the residual(C20+) range and (2) a variable distribution of resolved 4-to 6-ring nonalkylated (parent) PAHs, mostly dominatedby fluoranthene and pyrene (and exhibiting a FL/PY ratioof 0.9 ± 0.2). The variable nature of both the THC and PAHdistributions testifies that, while there is a generalconsistency to urban background, there are definitedifferences between (and even within) different urbansettings. This indicates that there is no single "representative"urban background THC or PAH signature. The greatestmass of THC is reasonably attributable to heavy petroleum(s) comprising the UCM, whereas the greatest mass ofPAHs is reasonably attributable to combustion-derivedparticulate matter. The mean concentration of THC attributableto urban background was 415 mg/kg (dry wt). Theconcentration of EPA 16-Priority Pollutant PAHs was lessthan 20 000 
g/kg (dry wt) in 96% of the sedimentsstudied. Thus, sediments containing significantly morethan 20 000 g/kg of the EPA 16 Priority Pollutant PAHs(or more the 30 000 g/kg of 43 parent and alkylated PAHs)should be suspected to contain PAHs not entirelyattributable to urban background, unless site- or regional-specific survey data supports a different urban backgroundconcentration profile.
g/kg (dry wt) in 96% of the sedimentsstudied. Thus, sediments containing significantly morethan 20 000 g/kg of the EPA 16 Priority Pollutant PAHs(or more the 30 000 g/kg of 43 parent and alkylated PAHs)should be suspected to contain PAHs not entirelyattributable to urban background, unless site- or regional-specific survey data supports a different urban backgroundconcentration profile.