Abstract
The relationship between benzo[a]pyrene (B[a]P) and 18 other polycyclic aromatic hydrocarbons (PAHs) found in coal tar pitch volatiles has been studied during summer and winter in a Söderberg-type primary aluminum smelter over a 4-year period. Samples were collected at the source, the electrolytic cell, at the overhead cranes in each potroom, and on workers, the same sites being kept for the duration of the study. This study confirmed the excellent relationship between B[a]P and total PAH concentrations and revealed that B[a]P was also a good indicator for individual PAHs in coal tar pitch volatiles. Benzo[a]pyrene relative abundance ratios (PAH/B[a]P), derived on the basis of this relationship showed remarkable stability as long as electrolytic process conditions were not changed. In the absence of any such changes, these values could allow retrospective estimates to be made of the concentration of any of the 18 PAHs selected or total PAHs based solely on the concentration of B[a]P measured at a given site. When combined with B[a]P relative potency factors, these values yield B[a]P toxic equivalent concentrations for any sites where B[a]P levels are known. This parameter provides a viable alternative to all other means of assessing exposure to a complex mixture such as PAHs.