Spatiotemporal distribution and priority assessment of steroids in the estuarine environment: Implications for...

Steroids, known for their endocrine-disrupting capabilities, have become a subject of considerable concern in the scientific community. This research offers a thorough evaluation of steroid contaminants within the Jiulong River Estuary (JRE), examining their spatiotemporal distribution, multimedia distribution, and mass inventory. Seven steroids were detected in water samples, while ten steroids were identified in sediments, with concentrations ranging from 0.2 to 51 ng/L in water and no-detectable (ND) to 12 ng g^-1 in sediments. In both water and sediments, natural steroids were the most prevalent throughout both the dry and wet seasons. The distribution of these compounds within the aquatic-sediment system was governed by their hydrophobicity and a suite of environmental factors, such as temperature, salinity, pH, chlorophyll-a, and total organic carbon content. Mass inventory analysis revealed that over 90 % of the total steroid mass inventory was stored in the sediments, underscoring their pivotal role as a repository for these substances within the JRE. Furthermore, this research represents the first comprehensive screening to identify priority contaminants in this region. Utilizing a multi-metric evaluation approach, progesterone and testosterone were identified as high-priority pollutants during the dry season, with progesterone alone ranking as a high-priority pollutant in the wet season. This study provides crucial insights for the management of steroid-related pollution and the assessment of environmental risks in estuarine ecosystems.