Key role of suspended particulate matter in assessing fate and risk of endocrine disrupting compounds in a complex river-lake system

Endocrine-disrupting compounds (EDCs) enter lakes mainly through river inflow. However, the occurrence, transport and fate of EDCs in the overlying water, suspended particulate matter (SPM) and sediment of inflowing rivers remain unclear. This study investigated the load of seven EDCs in a complex river-lake system of the Taihu Lake Basin during different seasons, with the aims of revealing the transport routes of EDCs and identifying the contributions from different sources. The results indicated that the levels of the seven EDCs in the wet season with high temperature and dilution effects were generally lower than those in the other seasons. EDC enrichment in the sediment was largely affected by the transport and fate of SPM. Moreover, the estrogenic activity and risks of EDCs were the highest in SPM. The mass loadings of particulate EDCs carried by SPM were 2.6 times that of overlying water. SPM plays a vital role in the transport and fate of EDCs in complex river-lake systems and thereby deserves more attention. Nonpoint sources, particularly animal husbandry activities and untreated domestic sewage, were the main sources of EDCs, amounting to 61.5% of the total load.