title: Impacts of sanitation improvement on reduction of nitrogen discharges entering the environment from human excreta in China.
abstract: Identifying the sanitation efficacy in reducing contaminations entering the environment is an important step for water pollution controls and developing management strategies to further improve sanitation conditions. With continuous efforts in sanitation improvement during the past decade, reductions in discharges of aquatic nutrients are expected in China. In this study, we estimated the aquatic nitrogen discharges from human excreta in 31 provinces in China during 2006-2014. The results indicated that the nitrogen discharges entering the environment from human excreta are largely determined by both local population and sanitation conditions. In 2014, the nitrogen discharges from human excreta in the rural areas (2118(1219-3140) Gg per year) (median and 95% confidence interval) are higher than those in the urban areas (1485(626-2495) Gg per year). The significant relationship (R2=0.38, n=29) between the total nitrogen concentrations in lakes and corresponding local nitrogen discharges indicated that, the lakes might be potentially affected by the contaminant inputs from human excreta. The further calculations under two policy scenarios showed that through sanitation improvement, further reduction of nitrogen discharges from human excreta in the developed regions might be limited. The sanitation improvement in the less-developed regions, such as Tibet, Qinghai, and Ningxia, should be considered a priority due to the larger reduction potentials.
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China. Electronic address: yindongtong@tju.edu.cn.
authors.forename: Yindong
authors.initials: Y
authors.lastname: Tong
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Xiaoge
authors.initials: X
authors.lastname: Bu
authors.affiliation: Tianjin Environmental Sanitation Engineering Design Institute, Tianjin 300201, China.
authors.forename: Cen
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Yiren
authors.initials: Y
authors.lastname: Lu
authors.affiliation: College of Urban and Environment Science, Tianjin Normal University, Tianjin 300387, China.
authors.forename: Huijiao
authors.initials: H
authors.lastname: Liang
authors.affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors.forename: Maodian
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors.forename: Huiming
authors.initials: H
authors.lastname: Lin
authors.affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Norwegian Institute for Water Research, Oslo 0349, Norway.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Tianjin Architecture Design Institute, Tianjin 300074, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Hydrochina Huadong Engineering Design Institute, Hangzhou 311122, China.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Wu
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Guozhu
authors.initials: G
authors.lastname: Mao
authors.affiliation: School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Wang
mesh_terms: D002681:China; D005243:Feces / Q000737:chemistry; D006801:Humans; D009584:Nitrogen / Q000032:analysis*; D012499:Sanitation; D018609:Tibet; D014556:Urine / Q000737:chemistry; D014876:Water Pollution / Q000517:prevention & control*
chemical_list: D009584:Nitrogen
keywords: China; Human excreta; Nitrogen; Sanitation improvement; Urban and rural