PARENT SESSION
PT7 - Environmental Forensics: PAHs
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P656) Limitations of Urban PAH Source Determination using Priority Pollutant PAH data.

Echols, Kathy^*,1, Orazio, Carl¹, Gale, Robert¹, ¹ USGS, Columbia Environmental Research Center, Columbia, MO, USA

ABSTRACT- Heavy polyaromatic hydrocarbon (PAH) pollution exists in the sediments of the Grand Calumet River, Indiana Harbor and Indiana Harbor Canal. The sediments in this system have been exposed to numerous urban and industrial sources of PAHs for the better part of a century. A database of priority pollutant PAH sediment concentration data from various reports from the mid 1980s through 1999 (compiled by McDonald Associates) was used in the evaluations. PAHs from the system were evaluated in two ways: (1) multivariate statistical analysis using principal components analysis; and (2) determining pertinent PAH ratios. The principal components analysis showed that 97.6% of the sediment samples fell within the calculated model (95% confidence ellipse) and showed no separation of samples based on the type of PAH source, indicating that the patterns of sedimentary priority pollutant PAHs in this system are similar. This could be because the system is so well mixed, or due to fact that the data set did not have sufficient information to differentiate sources. The PAH ratios inferred that the majority of the priority pollutant PAHs in this system were from anthropogenic combustion, but did not indicate the type of non-point and point sources (automobile exhaust, power plants, industrial pollution from coke, coal and petroleum, highway runoff, etc.). However, the use of the ratios was limited by the lack of alkylated PAHs and other hydrocarbons in the data set, which does not allow for a definitive determination of the sources of PAH contamination. Also, little or no priority pollutant PAH data existed for sources in this system (Indiana Harbor/Canal/Grand Calumet).

Key words: polyaromatic hydrocarbons, sediment, sources, pattern evaluation