抄録
An antifungal agent triclosan (TCS) and an anionic surfactant linear alkylbenzene sulfonate (LAS) were listed as candidates of detailed ecotoxicological risk assessment by Japan Ministry of Environment. These two compounds were selected to investigate the detailed fate and transport of these household effluent-originated pollutants in a small urban stream, Tsumeta Creek, Tokushima, Japan with no sewer system. Laboratory biodegradation and photodegradation experiments were conducted to determine first-order rate constants. Using these parameters and the environmental loading estimated based on PRTR or other statistics, a simple numerical model was constructed to estimate aquatic concentrations of TCS and C12-LAS in each sampling point in Tsumeta Creek and these values were compared with the measured values. Overall, the estimated values were acceptable and were in the range of 50 to 200% of the measured ones. The results suggest the concentration of TCS and C12-LAS is in the level of potential effects on aquatic organisms. From the viewpoint of the conservation of ecosystem, the mechanism of aquatic pollution and the removal of environmental loading of household effluent-originated pollutants such as TCS and LAS need to be further investigated in the unsewered area using both model prediction and monitoring.
