Parabens and Their Metabolites in Surface Sediment from Estuaries to the Sea: Occurrence, Spatial Distribution, and Potential Sources

Parabens have received significant attention due to their endocrine-disrupting properties. However, there is little information on paraben pollution in surface sediments across estuary, coastal, and marine environments within the same geographical areas. In this study, we investigated thoroughly the occurrence, spatial distribution, potential sources, and ecological risks of parabens and 4-hydroxybenzoic acid (4-HB) in estuarine, coastal, and marine sediments across the Beibu Gulf, South China Sea. Methylparaben (MeP) and 4-HB were the predominant target analytes in sediment samples, with concentrations ranging from 0.19 to 11.5 and from 5.80 to 130 ng/g dry weight, respectively. The estimated annual mass inventories deposited in the Beibu Gulf sediments were 3.00 tonnes for MeP and 45.4 tonnes for 4-HB. There was a distinct decrease in analyte concentrations from estuaries to the sea, suggesting that riverine input and point-source pollution from Weizhou Island were probably the primary sources of paraben pollution in the Beibu Gulf. All target analytes posed negligible ecological risks in the study region. This study presents the first comprehensive survey of parabens in sediments in the Beibu Gulf and contributes to our understanding of their environmental behavior and potential ecological risks.