Halogenated PAH Contamination in Urban Soils

Abstract

Halogenated polycyclic aromatic hydrocarbons (HPAH) such as Cl-PAH and Br-PAH are new ubiquitous environmental aromatic contaminants. We found HPAH in urban soils and river sediments in Japan. We developed the analysis of HPAH by gas chromatography-electron ionization-tandem mass spectrometry. 20 Cl-PAH, 11 Br-PAH, and 16 PAH were analyzed. We found concentrations from 55.6 to 534,000 ng/g for Cl-PAH, 3.14-914 ng/g for Br-PAH and 19,800-1,080,000 ng/g for PAH. Similar compositions of HPAH were observed among some soil samples, suggesting that common emission sources. The highest contaminations of Cl-PAH were observed in old chlor-alkali plant soils. To test HPAH origin from the industry, electrolysis of brine in the presence or absence of pitch were carried out in the laboratory. We found that congener and homolog profiles of HPAH produced by electrolysis are consistent with those of soils from old chlor-alkali plant sites. Consequently, chlor-alkali production facilities including electrolysis of brine in the presence of graphite could be an unintentional source of HPAH in the environment.