Flow of sewage sludge-borne phthalate esters (PAEs) from human release to human intake: implication for risk assessment of sludge applied to soil.
The wide production and use of phthalate esters (PAEs) in both industry and commercial products lead to their ubiquitous existence in the environment. However, understanding flow and pathway of human exposure to PAEs from sources to receptors is necessary and challenging. In this study, we selected final sewage sludge, an inevitable byproduct of wastewater treatment plants (WWTP), as one type of important carrier/sources of PAEs to clarify the flow of PAEs between human and the environment, e.g. the release by human to sludge and in turn ingestion by human after these sludges were disposed as soil amendment. Twenty-five sludge samples were collected from 25 wastewater treatment plants (WWTPs) in Shanghai, East China. Of all 16 PAE congeners, di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DnBP) were predominant with mean concentrations of 97.4 and 22.4 μg/g dw, respectively, both locating at the high end of the global range. WWTP treating industrial waster generally contained higher PAEs compared to those treating domestic wastewater, but no positive relationship was found between PAE levels with the percentage of industrial wastewater. Principal component analysis (PCA) showed that similar PAE sources for all WWTPs in Shanghai with three exceptions, in which specific PAE products were made. The annual mass loadings via sludge of DEHP, DnBP, and Σ16PAEs were 31.4, 7.44, and 39.6 tons in Shanghai and 1042, 247, and 1314 tons in China, respectively, only accounting for 0.09% of the total consumption of PAEs in China. If this sludge is applied in soil, human will take 16.4 and 3.8 μg/kg bw for DEHP and DnBP every day, respectively, via dietary and soil ingestion, which were lower than the toxicological safety parameters. To the best of our knowledge, this is the first report to analyze the flow of sludge-borne PAEs from human release to human intake.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. Electronic address: xzmeng@tongji.edu.cn.
Xiang-Zhou
XZ
Meng
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Ying
Y
Wang
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Nan
N
Xiang
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Ling
L
Chen
National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Zhigang
Z
Liu
National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Bing
B
Wu
National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. Electronic address: daixiaohu@tongji.edu.cn.
Xiaohu
X
Dai
Key Laboratory of Public Health Safety, Ministry of Education, School of Public Health, Fudan University, Shanghai 200032, China.
Yun-Hui
YH
Zhang
Department for Environmental Chemistry, Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Geesthacht 21502, Germany.
Zhiyong
Z
Xie
Department for Environmental Chemistry, Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Geesthacht 21502, Germany.
Ralf
R
Ebinghaus
D057914:Agricultural Irrigation / Q000379:methods*; D002681:China; D010795:Phthalic Acids / Q000032:analysis*; D018570:Risk Assessment; D012722:Sewage / Q000737:chemistry / Q000706:statistics & numerical data; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry / Q000706:statistics & numerical data
D010795:Phthalic Acids; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D062065:Wastewater
Human exposure; Phthalate esters (PAEs); Sludge; Soil