Toxicity testing of 16 priority polycyclic aromatic hydrocarbons using Lumistox®

Hazard assessment of industrial sites contaminated with coal tar and its products usually focuses on selected pollutants such as the 16 polycyclic aromatic hydrocarbons (PAHs) prioritized by the U.S. Environmental Protection Agency (U.S. EPA). The aim of this study was to investigate to which extent these 16 PAHs contribute to the Vibrio fischeri bioluminescence inhibition measured by the acute Lumistox luminescent bacteria test. Five of the 16 PAHs-naphthalene (NAP), acenaphthylene (ACY), acenaphthene (ACE), fluorene (FLU), and phenanthrene (PHE)-revealed inhibiting effects when measuring saturated aqueous solutions of these compounds. However, in elutriates of PAH-contaminated soils, the amount of leached PAHs was very low, and the 16 PAHs did not considerably contribute to the observed bioluminescence inhibition. Nevertheless, bioluminescence inhibition was higher for elutriates with increased PAH concentration indicating the presence of other toxicants that co-occur with the 16 PAHs. No evidence was observed for increased bioluminescence inhibition due to synergistic effects among PAHs as calculated on the basis of toxic units for an aqueous solution containing all 16 priority PAHs. Data suggest that the U.S. EPA PAHs play only a minor role in causing acute toxicity to V. fischeri when exposed to aqueous elutriates of PAH-contaminated soils.