Effects of Light Intensity on the Phototoxicity of Fluoranthene to a Benthic Macroinvertebrate

摘要

Conceptual models suggest that the toxicity of pho-toactivated polycyclic aromatic hydrocarbons (PAHs) should be a direct function both of chemical (PAH) dose and intensity of the ultraviolet (UV) light to which the organism is exposed. However, there have been only limited studies with aquatic organisms to quantify the relationship between PAH dose and UV intensity in producing phototoxicity. In this study, oligochaetes (Lumbriculus variegatus) were exposed, via the water, to multiple concentrations of fluoran-thene, a PAH known to be phototoxic, and then placed under UV light at three different intensities. The resultant phototoxicity clearly was a function both of PAH dose and light intensity. Time-dependent mortality of the oligochaetes could be accurately predicted through evaluation of the product of fluoranthene dose (in the tissue of the animal) and light intensity to which the organisms were exposed. These results indicate that criteria for phototoxic chemicals should incorporate consideration not only of xenobiotic exposure but also of light intensity in specific aquatic environments.