PHOTOMODIFICATION EFFECT ON THE PHOTOINDUCED TOXICITY OF FOURTEEN ANTHRAQUINONES TO DAPHNIA MAGNA

摘要

The toxicity of chemicals can be enhanced by light through two pathways: photomodification to more toxic substances and photosensitization reactions. The photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) has been well documented; however, little information is available concerning other environmental contaminants. Anthraquinones derivatives (AQs) are a group of important chemicals used in dye, pharmaceutical and pulp industries. The photoinduced toxicity of AQs potentially exists due to their absorption of visible and ultraviolet light. Moreover, some AQs can be phototransformed to other chemicals. The photomodification effect on the photoinduced toxicity of AQ dyes to Daphnia magna was assessed in the present study. Ten of 14 studied AQs showed phototoxic activity under simulated solar radiation (SSR). The photoinduced toxicity of six unphotostable AQs was reduced when they were photomodified under SSR. The order of medium effective concentration (EC50) ratio (photomodified/intact AQs) was almost consistent with the rate of photomodification. The present study can provide useful information for the ecological risk of AQs and a better understanding of their potential photoinduced toxicity mechanism.