Comprehensive management of chemical substances in a water environment using PRTR data.

The annual quantity of discharge of 354 chemical substances from each business has been released based on PRTR law in Japan since 2003. MLIT and municipalities should be responsible for managing chemical risk in public water bodies through communication with stakeholders, such as the public and businesses. However, it is economically difficult to measure the discharge loads and behaviour of all chemical substances and reveal which substances should be particularly managed in each basin. NILIM has begun studies on survey methods to understand the discharge and behaviour of chemical substances in each basin based on PRTR information, and to conduct risk management of chemical substances in cooperation with stakeholders such as the public and businesses. We selected 30 chemical substances, such as those listed or nominated in environmental criteria and endocrine disrupters, collected the volume of discharge of chemical substances from public and industrial wastewater treatment plants using PRTR information, and surveyed their behaviour in the river in the model area. As a result, the discharge of 12 chemical substances were reported in PRTR, and 17 substances were detected in the river. Some inorganic compounds were detected intensively near discharge sites reported in the PRTR. But some organic compounds and endocrine disrupters, such as oestrone, were detected although their discharge was not reported in the model area in the PRTR. It suggested that PRTR information is useful to identify hot spots, but further study is needed to understand the discharge of chemical substances from small businesses, farmland and houses.