Spatial and seasonal distributions of estrogens and bisphenol A in the Yangtze River Estuary and the adjacent East China Sea

Surface water and sediments in the Yangtze River Estuary (YRE) and the adjacent East China Sea (ECS) were sampled to investigate the spatial and seasonal distributions of Estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2) and bisphenol A (BPA). E1 and BPA were the dominant compounds detected. The zones of the highest E1 and BPA concentrations in water were located at the mouth of the Huangpu River and the outfalls of wastewater treatment plants. The zones of the highest concentrations in sediments were mainly located in the down reach of the estuary and the adjacent sea. The relationship between E1 and BPA in sediments with those in water was not significant (BPA: r = 0.16, p = 0.21; E1: r = 0.18, p = 0.24), but positive correlations with the total organic carbon (TOC) contents of sediments (BPA: r = 0.57, p < 0.01; E1: r = 0.33, p = 0.04) and negative correlations with the sand contents of sediments (BPA: r = −0.52, p < 0.01; E1: r = -0.16, p = 0.23) were found. The TOC contents were the major factor influencing the E1 and BPA distributions in sediments. The hierarchical cluster analysis further indicated the spatial distributions of BPA and E1 in sediments were obviously affected by TOC and sediment particle sizes, whilst the distributions varied slightly with seasons.