Spatial Distribution, Compositional Profiles, and Potential Ecological Risks of Rubber Additives in Sediments of Lake Sihwa, South Korea: Insights into Industrial and Road-Derived Toxic Substances

This study evaluates the distribution, composition, and potential ecological risks of rubber additives (RAs) in sediments (n = 22) and road dust (n = 2) from inland creeks and Lake Sihwa, South Korea, an area heavily influenced by industrial and vehicular emissions. A total of 20 RAs, including vulcanization accelerators, antioxidants, and coating agents, were analyzed using HPLC-MS/MS. RA concentrations ranged from 21 to 1100 ng g–1 dry weight (dw), with the highest levels detected near new industrial areas. Notably, benzothiazole (BT), N-isopropyl-N′-phenyl-p-phenylenediamine (6PPD), and its transformation product, 6PPD-quinone (6PPD-Q), were the predominant contaminants. Road dust exhibited RA concentrations of 300 and 1270 ng g–1 dw, with vulcanization accelerators, such as diphenylguanidine and BT derivatives, as key constituents. Ecological risk assessments identified 6PPD-Q as a major contributor to acute toxicity, while BT posed significant chronic toxicity risks. Sites influenced by road dust deposition and industrial emissions exhibited heightened vulnerability, indicating potential threats to aquatic ecosystems. This study provides crucial baseline data on RAs contamination, underscoring the need for continuous environmental monitoring and regulatory intervention. Future research should focus on identifying additional sources, assessing ecotoxicological effects, and developing strategies to mitigate risks associated with industrial and traffic-related pollutants.