Initial Environmental Risk Assessment of Japanese PRTR Substances in Treated Wastewater

Abstract

This study aimed to collect fundamental information on environmental risks posed by Class 1 chemicals under the Japanese Pollutant Release and Transfer Register (PRTR) system. The concentration of the substances in treated wastewater was estimated using the publicly available information in the PRTR system. Initial ecological and human health risk assessments were performed by comparing the estimated concentration and existing toxicity indexes on the basis of a hazard quotient (HQ). The results showed that linear alkylbenzene sulfonate (LAS) and its salts had the highest concentrations (166 μg/L). Thirty-six (e.g., hydrazine) and 11 chemicals (e.g., glutaraldehyde) had high HQ values (≥ 0.1) in initial ecological and human health risk assessments, respectively. Using comparisons between a previous study and this study, an interannual variability of high HQ value chemicals revealed that the composition of chemicals for ecological risk was similar for the different periods; however, it was different for human health risk. Further monitoring and development of countermeasures against the chemicals are required to avoid ecological and health risks.