Xu Xin, Zou Yiyang, Pan Hongru, Zhang Ruoxi, Gu Baojing
College of Environmental & Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Policy Simulation Laboratory, Zhejiang University, Hangzhou 310058, China.
Environ Sci Technol. 2025 Jan 14;59(1):467-477. doi: 10.1021/acs.est.4c08197. Epub 2024 Dec 19.
Groundwater, essential for irrigation, industry, and drinking, plays a crucial role in environmental health and human well-being. A major threat to groundwater quality is nitrate pollution, primarily stemming from human activities. Safeguarding nitrogen levels in groundwater within regional thresholds remains a global challenge. By integrating 3,134 groundwater samples and nitrogen budget modeling, we found that China's national average nitrate concentration has risen by 29% since the 2000s, reaching 14 mg N L. The main sources of nitrate contamination are cropland, landfills, and wastewater disposal, with average annual nitrogen leaching of 1.91 ± 0.16, 0.86 ± 0.18, and 0.63 ± 0.17 million tonnes, respectively; these sources collectively account for 73% of the total nitrate leakage during 2000-2020. Current robust mitigation practices could reduce nitrogen leaching into groundwater by 45% (1.93 million tonnes N), delivering a net societal benefit of US$83 billion in China. Nevertheless, this reduction remains insufficient to meet the safe nitrogen boundary for all provinces, underscoring a compelling necessity for additional measures and policy guidance tailored to protect groundwater resources on a site-specific basis.
地下水对灌溉、工业和饮用至关重要，在环境卫生和人类福祉方面发挥着关键作用。地下水质量的一个主要威胁是硝酸盐污染，主要源于人类活动。将地下水中的氮含量控制在区域阈值内仍是一项全球挑战。通过整合3134个地下水样本和氮预算模型，我们发现自21世纪以来，中国地下水硝酸盐平均浓度上升了29%，达到14毫克氮/升。硝酸盐污染的主要来源是农田、垃圾填埋场和废水处理，年均氮淋失量分别为191±16万吨、86±18万吨和63±17万吨；这些来源在2000年至2020年期间的硝酸盐泄漏总量中占73%。目前强有力的缓解措施可使进入地下水的氮淋失量减少45%（193万吨氮），在中国带来830亿美元的净社会效益。然而，这一减少量仍不足以满足所有省份的安全氮边界，凸显了针对特定地点保护地下水资源采取更多措施和政策指导的迫切必要性。
