Benzo[b]fluoranthene,a Potential Alternative to Benzo[a]pyrene as an Indicator of Exposure to Airborne PAHs in the Vicinity of Söderberg Aluminum Smelters

ABSTRACT

Benzob]fluoranthene (Bb]F) was used in relative abundance ratios (RARs), a parameter obtained by dividing the concentration of individual polycyclic aromatic hydrocarbons (PAHs) found in a given sample by the concentration of Bb]F in the same sample. The Bb]F RARs were derived for PAH concentrations measured at stacks and sampling stations in the vicinity of two Söderberg aluminum horizontal stud smelters (HSSs). The samples collected were analyzed by high-performance liquid chromatography using UV and fluorescence detection. A total of 15 PAHs were analyzed, but, due to the inefficiency of the sampling method used in collecting gaseous PAHs, only particulate PAHs were considered. Comparisons between the Bb]F RARs obtained simultaneously at the source (stack) and those obtained at sampling stations at the two smelters showed that Bb]F degrades more slowly than or at the same rate as most other particulate PAHs monitored. Twenty-three months of urban sampling in the vicinity of one of the aluminum HSSs are also presented, and the results indicate that Bb]F is more stable than all other particulate PAHs investigated. Sampling conducted during a smelter shutdown period confirmed that Bb]F was a much better marker of this source than was benzoa]pyrene (Ba]P), the usual indicator. The remarkable stability of the benzok]fluoranthene (Bk]F)/Bb]F ratio is also discussed.