Development of Watershed Model for Chemical Risk Assessment in Aquatic System

Abstract

The research center for Chemical Risk Management (CRM) of the National Institute of Advanced Industrial Science and Technology (AIST) has developed a watershed model for chemical risk assessment in river basins and for evaluating emission reduction measures, which was released as an AIST-Standardized Hydrology-based AssessmeNt tool for chemical Exposure Load (AIST- SHANEL). This model is used to estimate chemical exposure concentrations in water systems using a spatial resolution of 1×1 km grid and a time resolution of 1 day by inputting of simple data such as Pollutant Release and Transfer Register (PRTR) release data, river basin information, and data on the basic physical properties of the chemical substances of interest. Various types of information can be easily derived from calculations made using this tool, including the location of high-release areas within a river basin, the correlation between exposure load and areas with high releases, and the relationships between river flow rate and exposure load. The calculated values were fitted with the measured data for nonylphenol ethoxylates (NPnEOs), nonylphenol (NP), linear alkylbenzene sulphonate (LAS) and bisphenol A (BPA) by a factor of 10, which indicates the validity of this model.