Contamination, multimedia partitioning, and priority list of steroids and their metabolites in coastal regions of the Greater Bay Area, China

Abstract

Steroids and their metabolites, with potential carcinogenic and endocrine-disrupting properties, have raised global health concerns. The Guangdong-Hong Kong-Macao Greater Bay Area (GBA), a globally recognized major bay area with a large population and important livestock and aquaculture industries, is a key source of steroids in the environment. Therefore, understanding the contamination status and ecological risks of these substances in GBA is particularly crucial due to their potential impacts on aquatic biodiversity and ecosystem health. This study systematically quantified 28 steroids and their metabolites across six coastal regions in GBA. Ten and nine steroids were identified in coastal water and sediments with levels of < 0.054 −5.3 ng/L and 0.98 −9.3 ng/g, respectively, with natural steroids being the predominant contributors. Compared to water, steroids and their metabolites were more likely to accumulate in sediments. Steroid hydrophobicity and environmental parameters (pH, temperature and salinity) can affect their distribution in coastal environments. While minimal and low ecological risks currently posed by steroids were found in water, specific compounds, such as progesterone and testosterone, warrant closer scrutiny due to their high priority status in aquatic environments, as determined by factors including occurrence, persistence, bioaccumulation and ecotoxicity. These findings provide foundational insights into steroid contamination in GBA, contributing to the understanding of their environmental behavior and supporting future risk assessments for this ecologically vital area.