Wu Junhua, Chen Yiping, Ma Jifu, Cao Jing, Jiang Yao
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Foods. 2022 May 13;11(10):1409. doi: 10.3390/foods11101409.
Heavy metal elements in farmland soil can be absorbed by crops and endanger food security. To assess the risk of heavy metal elements in farmland soil to crops in Shaanxi Province, we collected 693 soil samples and analyzed the concentrations of nine heavy metals (As, Hg, Pb, Cd, Cr, Mn, Cu, Zn, and Ni). According to the National Standard (GB 15619-2018) of the People’s Republic of China, the proportions of soil sample points in which the concentration of heavy metals was higher than the risk screening value were 2.02% (Cd), 0.29% (Cr), 0.29% (Zn), 2.31% (Cu), 1.15% (Ni), and 0.14% (Pb). The proportions of areas in which the concentration of heavy metal was higher than the background value were as follows, from largest to smallest: Zn (53.20%) > Mn (49.86%) > Cd (29.51%) > Hg (26.77%) > As (26.58%) > Ni (14.95%) > Cu (13.90%) > Pb (6.49%) > Cr (1.40%). The assessment of the risk of heavy metal exposure (geo-accumulation index (Igeo), pollution load index (PLI), and potential ecological risk index (RI)) determined that Hg was the most concerning heavy metal in the farmland soil of Shaanxi Province. Moreover, 11.56% of these areas had Hg contamination, and they were mainly distributed in the western Guanzhong region. The farmland soil in the Guanzhong region was the most contaminated, followed by the southern Shaanxi region and then the northern Shaanxi region. The main sources of heavy metal contamination causing large-scale farmland soil pollution are agricultural production activities, transportation, and air pollution caused by coal combustion in Shaanxi Province. Therefore, sustainable strategies for the prevention and control of heavy metal pollution and agricultural development must be applied in different regions. Heavy metal pollution should be managed, and relevant policies should be created and enforced, such as the standardization of the use of qualified pesticides and fertilizers, improved treatment of livestock and poultry manure, development of the clean energy industry structure, and promotion of renewable energy vehicles. In terms of the high-quality development of agriculture, developing modern and local agriculture in different regions should be based on local geographical, climatic, and economic conditions.
农田土壤中的重金属元素会被农作物吸收，危及粮食安全。为评估陕西省农田土壤中重金属元素对农作物的风险，我们采集了693个土壤样本，并分析了9种重金属（砷、汞、铅、镉、铬、锰、铜、锌和镍）的含量。根据中华人民共和国国家标准（GB 15619 - 2018），重金属含量高于风险筛选值的土壤采样点比例分别为：镉2.02%、铬0.29%、锌0.29%、铜2.31%、镍1.15%、铅0.14%。重金属含量高于背景值的区域比例从大到小依次为：锌（53.20%）＞锰（49.86%）＞镉（29.51%）＞汞（26.77%）＞砷（26.58%）＞镍（14.95%）＞铜（13.90%）＞铅（6.49%）＞铬（1.40%）。重金属暴露风险评估（地累积指数（Igeo）、污染负荷指数（PLI）和潜在生态风险指数（RI））表明，汞是陕西省农田土壤中最令人担忧的重金属。此外，这些区域中有11.56%存在汞污染，主要分布在关中西部地区。关中地区的农田土壤污染最为严重，其次是陕南地区，然后是陕北地区。造成大面积农田土壤污染的重金属污染主要来源是陕西省的农业生产活动、交通运输以及煤炭燃烧造成的空气污染。因此，必须在不同地区实施重金属污染防治和农业发展的可持续战略。应管理重金属污染，并制定和执行相关政策，如规范合格农药和化肥的使用、加强畜禽粪便处理、发展清洁能源产业结构以及推广新能源汽车。在农业高质量发展方面，应根据不同地区的地理、气候和经济条件，发展现代特色农业。
