Occurrence, spatial distribution and ecological risk assessment of phthalate esters in water, soil and sediment from Yangtze River Delta, China

A total of 96 water, soil, and sediment samples, collected from 32 sampling sites in the Yangtze River Delta (YRD) region, were analyzed for 9 phthalate esters (PAEs). The sum concentrations of 9 PAEs (Sigma(9)PAEs) in the water, soil, and sediment samples were 2.23-630 mu g L-1 (mean: 4.11 mu g L-1), 155-1410 mu g kg(-1) (408 mu g kg(-1)), and 30.1-16,000 mu g kg(-1) (1200 mu g kg(-1)), respectively. Among the 9 PAEs, di-n-butyl phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP), and di-isobutyl phthalate (DIBP) are the predominant congeners in the YRD region. DBP was the dominant PAE congener in water, accounting for 50.6% of the Sigma(9)PAEs, while DEHP was the pre-dominant one in soil and sediment (accounting for 69.6% and 83.1% of the Sigma(9)PAEs, respectively). Soil and sediment samples collected from Wuxi city manifested relatively higher PAE concentrations. The partitioning of PAEs between water and sediment was attributed to the fact that low molecular weight PAEs (e.g., dimethyl phthalate (DMP) and diethyl phthalate (DEP)) were dominant in water, medium molecular weight PAEs (e.g., BzBP) were close to the equilibrium between sediment-water, and high molecular weight PAEs (e.g., DEHP) were more prevalent in sediment. The ecological risk assessment of PAEs in the surface water showed that the potential environmental risks followed the order of DEHP > DIBP > DBP > DMP > DEP. Comparatively, DEHP posed high ecological risk to sensitive algae, crustaceans and fish, while DMP and DEP exhibited low risk. In the sediment, DIBP exhibited a high risk to the sensitive fish, whereas DMP, DEP, DBP and DEHP displayed no risk. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study found that PAEs are the main contaminants present in water, soil, and sediment in the Yangtze River Delta region, with DBP, DEHP, and DIBP being the predominant congeners. DEHP was dominant in soil and sediment, while significant differences were observed in the distribution of PAEs between water and sediment.