Contamination and spatial distribution of parabens, their metabolites and antimicrobials in sediment from Korean coastal waters

Synthetic antimicrobials known as parabens, triclosan (TCS), and triclocarban (TCC) are emerging environmental contaminants. Limited studies on these contaminants have been conducted in coastal environments. In our study, parabens, their metabolites, TCS, and TCC were measured in sediment collected along the Korean coast, to investigate contamination status, spatial distribution, and potential health risks to coastal environments. Methyl paraben and 4-hydroxybenzoic acid were detected in all sediment samples, suggesting widespread contamination. Total concentrations of parent parabens, their metabolites, TCS, and TCC ranged from 0.19 to 11.2 (mean: 2.40) ng/g dry weight, 9.65 to 480 (mean: 120) ng/g dry weight, and < limit of quantification (LOQ)-6.10 (mean: 0.41) ng/g dry weight, and from < LOQ-41.0 (mean: 2.78) ng/g dry weight, respectively. The overall contamination of parabens and antimicrobials in sediment was different from that reported for persistent organic pollutants due to different contamination sources among chemical groups. Significant correlation was found among target contaminants in sediment, suggesting the existence of a common source. Total organic carbon (TOC) was significantly correlated with the concentrations of target contaminants, implying a major factor for coastal distribution of parabens and antimicrobials. The concentrations of parabens and TCS measured in sediment did not exceed a hazard quotient (HQ), implying low potential health risks associated with exposure to these contaminants. This is the first study to report the nationwide distribution of parabens, their metabolites, and antimicrobials in the coastal environments of Korea.