Short- and long-term ecological risk assessment of phthalate esters in freshwater and sediment using interspecies correlation estimation, acute–chronic ratio, and species sensitivity distribution models

Phthalate esters (PAEs) are typical industrial and agricultural chemicals that are readily released into the environment. Due to their endocrine-disrupting properties, PAEs pose considerable ecological risks in different environmental matrices. However, current standards for evaluating the ecological risks of PAEs focus primarily on environmental quality thresholds and do not account for criteria based on native species. This study integrated species sensitivity distribution modeling, interspecies correlation estimation, and acute-chronic ratio calculations using toxicity data for seven representative PAEs from native species in freshwater: dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DnBP), butyl benzyl phthalate (BBP), dis(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), and dihexyl phthalate (DnHP). Short- and long-term predicted no-effect concentrations (PNECs) were estimated and applied to the ecological risk assessment (ERA) for these PAEs in freshwater and sediment across major basins of China. The PNECs for DIDP and DnHP were derived for the first time. The values of PNECs for the remaining PAEs were generally lower than or similar with previously reported values. The freshwater ERA results indicated a consistent risk ranking of DEHP > DnBP > BBP > DEP > DMP (DnHP) for acute and chronic exposure. For sediment, the short- and long-term risk rankings differed, with acute risks following DnBP > DEP (DMP) > DEHP > BBP > DnHP and chronic risks following DEHP > DnBP > DEP > DMP > BBP > DnHP. The DEHP should be warranted as a particular concern in sediments, as its ecological risk increased over time.