UV-A coexposure enhances the toxicity of aromatic hydrocarbons, munitions, and metals to Photobacterium phosphoreum.

Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Photobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.). This paper reports that UV-A photoenhanced the toxicity of polynuclear aromatic hydrocarbons, other types of organic compounds, and some transition metals to P. phosphoreum. Coexposure to 400 muw/cm2 for 15 min increased the toxicity of psoralen, alpha-terthienyl, anthracene, acridine, fluoranthene, TNT, Cu2-, As3-, Ni2, and Cd2+. Phenanthrene was photoenhanced after 30 min coexposure at 400 muw/cm2-, and Mn2+ at 800 muw/cm2 after 15 min. Naphthalene was not enhanced at 800 muw/cm2 for 30 min.