Contamination and historical trends of legacy and emerging plasticizers in sediment from highly industrialized bays of Korea

Abstract

Domestic and global regulations on phthalates have led to the introduction of non-phthalate plasticizers (NPPs) in industrial markets as alternative plasticizers. In this study, phthalates and NPPs from surface and core sediment samples taken from industrialized bays in Korea were measured to determine their distribution, contamination sources, historical records, and the ecological risks they posed. Phthalates and alternative plasticizers were detected in all surface samples and sediment cores, indicating ubiquitous contamination. Predominant phthalates were di(2-ethylhexyl)phthalate (DEHP), diisononyl phthalate (DiNP), and diisodecyl phthalate (DiDP) and di(2-ethylhexyl)terephthalate (DEHT) and tris(2-ethylhexyl)trimellitate (TOTM) were the most common NPPs. The total concentrations of phthalates and NPPs ranged from 76.3 to 59,400 ng/g dry weight and <0.02 to 35,300 ng/g dry weight, respectively. The highest concentrations of phthalates and NPPs were observed in sediment from rivers, streams, and inner parts of bays, with the levels decreasing gradually toward the outer parts of the bays. Our findings suggest that proximity to industrial complexes is crucial for sedimentary distribution for plasticizers. Historical records in a sediment core show clearly increasing trends in phthalate and NPP levels from the 1970s to the 2010s, consistent with their production history. In particular, TOTM has rapidly increased over the last decade, presenting an emerging concern of contaminant in the coastal environment. Industrialization and population growth were suggested as major factors affecting plasticizer contamination. Almost all sediment (>95%) exceeded quality guidelines for DEHP, implying a potential risk for benthic organisms. This is the first report on historical trends of phthalates and alternative plasticizers. © 2020 Elsevier B.V.