Distribution characteristics and risk assessment of TBBPA in seawater and zooplankton in northern sea areas, China

Tetrabromobisphenol-A (TBBPA) is a typical persistent organic pollutant (POP) that is harmful to the environment and organisms. It easily accumulates in organisms and is transmitted along the food chain or food web for long distances and long periods of time. The experiment was designed to assess the TBBPA pollution levels in marine environments via environmental sample testing and risk assessment. TBBPA levels in seawater and zooplankton samples at each station (n = 38) were detected, whereafter the bioaccumulation factor (BAF) and risk quotient (RQ) were calculated to evaluate the potential bioaccumulation and ecological risk of TBBPA to zooplankton, respectively. The results showed that TBBPA was widely detected in surface seawater and zooplankton samples in the Yellow Sea and Bohai Sea, with levels ranging from ND (non-detected) to 0.46 mu g/L and ND to 9.83 mu g/kg (wet weight), respectively. In both the Yellow Sea and Bohai Sea, the distance from the shore was one of the main factors affecting the TBBPA concentration in seawater, regardless of visibility. The BAF was significantly correlated with the TBBPA content in zooplankton samples (P < 0.01), which ranged from 372.32 to 29,941.55, indicating that TBBPA exhibits an obvious bioaccumulation risk to marine zooplankton. The ecological risk assessment indicated that TBBPA levels in seawater pose a high ecotoxicity risk to zooplankton (RQ > 1). This finding suggests that both the significant bioaccumulation of TBBPA in marine ecosystems and its potential ecological risks cannot be ignored.