Occurrence of phthalate esters in river sediments in areas with different land use patterns

Phthalate esters (PAEs) are widely used as plasticizers in both industrial and commercial products and have aroused considerable concern over their widespread distribution and potentially hazardous impacts on the environment. The present study investigated the distribution (concentrations at different sites) of PAEs in typical riverine sediments in southern Jiangsu Province and its relationship with the physical and chemical properties of the sediments. PAEs were detected in all 34 sediment samples analyzed, and the total concentrations of the six priority control PAEs in sediments ranged from 2.3 to 80.1 mg kg(-1) with a mean concentration of 13.2 ± 14.7 mg kg(-1). Land use significantly (p<0.05) influenced the PAE concentrations in the river sediments. The average PAE concentrations in mixed industrial and commercial districts were 27.8 ± 18.2 mg kg(-1), three and eight times higher than those in suburban areas (8.8 ± 3.7 mg kg(-1)) and an agricultural field (3.4 ± 0.9 mg kg(-1)), respectively. The concentrations of PAEs showed significant linear positive correlations with sediment organic matter and phosphorus but no significant correlation with sediment pH. Di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the dominant PAE compounds present in all examined sediment samples. These PAEs have relatively high ecotoxicology, but the potential risk of their transfer to the food chain needs further study.