Evaluating polycyclic aromatic hydrocarbons using a yeast bioassay

Sixteen polycyclic aromatic hydrocarbons (PAHs) were evaluated for the ability to activate aryl hydrocarbon (Ah) receptor signaling in a yeast-based bioassay. Individual PAHs were classified as inactive or as weakly, moderately, or strongly active based on induction of human Ah receptor signaling. Indeno[1,2,3-cd]pyrene, chrysene, benzo[a]anthracene, benzo[a]pyrene, benzo[j]fluoranthene, and benzo[k]fluoranthene were the most potent activators of human Ah receptor signaling. Various mixtures of PAHs had additive or synergistic effects in the bioassay. Environmental samples from the New Orleans (Louisiana, USA) and Detroit (Michigan, USA) areas that were previously analyzed for PAH composition and quantity were tested in this bioassay. Weak but statistically significant relationships were found when the analytically measured levels of PAHs were correlated with sample dilutions that gave 25% effective concentration signaling levels in the Ah receptor assay. We conclude that this Ah receptor signaling assay may be useful for preliminary biomonitoring of samples for PAHs and other Ah receptor ligands.