宁波市地表水重金属时空分布特性和健康风险评价 |
摘要点击 2702 全文点击 967 投稿时间:2022-02-25 修订日期:2022-06-23 |
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中文关键词 地表水 重金属 时空分布 污染评估 健康风险 宁波 |
英文关键词 surface water heavy metals temporal-spatial distribution pollution assessments health risk Ningbo |
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中文摘要 |
分别在丰水期和枯水期,从宁波市工业区和商业区地表水中采集了120个水样,检测了6种重金属(Cd、Cr、Ni、Pb、Zn和Fe)的浓度水平,分析了它们的时空分布特征,计算了重金属间的斯皮尔曼相关系数;结合时空特征和斯皮尔曼相关系数推测了主要污染源;通过计算健康风险指数和致癌风险指数评价了地表水中重金属对暴露人群存在的风险.结果表明,宁波市工业区和商业区不同季节地表水重金属的污染特性有很大的差异.工业区丰水期和枯水期重金属浓度平均值的大小顺序分别为:Fe>Zn>Ni>Pb>Cr>Cd和Fe>Zn>Cr>Ni>Pb>Cd,超标的严重性顺序分别为:Cr>Cd>>Pb和Pb>Cr=Cd,含重金属工业废水是工业区地表水重金属的主要污染源之一.商业区丰水期和枯水期重金属浓度平均值的大小顺序分别为:Fe>Pb>Ni>Zn>Cd>Cr和Fe>Pb>Ni>Zn>Cr=Cd,丰水期超标的严重性顺序为:Cd>Pb;枯水期仅有Pb超标,超标率60%,公路源污染物是商业区地表水重金属污染的主要来源,地表径流和降水是重金属输入的重要途径.两个区地表水中的重金属对暴露人群均存在很大的致癌风险,且商业区高于工业区,主要的致癌物质都是Cr.和2015年采样的研究结果相比,两个区重金属的污染程度均减轻了很多,但今后仍需注意宁波市地表水重金属污染的防控. |
英文摘要 |
A total of 120 surface water samples were collected from industrial and commercial districts of Ningbo, China in the wet and dry seasons. The concentrations of six heavy metals (Cd, Cr, Ni, Pb, Zn, and Fe) in the samples were measured, the temporal-spatial distribution characteristics of the six heavy metals were analyzed, and Pearson correlation coefficients of the six heavy metals were calculated. Combined with the temporal-spatial distribution characteristics and Pearson correlation coefficients of the six heavy metals, the main pollution sources of the two districts were analyzed, respectively. The risk of heavy metals in surface water to the exposed population was evaluated by calculating the health risk index and carcinogenic risk index. The results showed that the pollution characteristics of heavy metals in the surface water of Ningbo industrial district and commercial district differed greatly in different seasons. In the industrial district, the orders of the average concentration of heavy metals in the wet season and dry season were Fe>Zn>Ni>Pb>Cr>Cd and Fe>Zn>Cr>Ni>Pb>Cd, respectively. The concentrations of Cr, Cd, and Pb in the wet and dry seasons exceeded the class Ⅳ recommended values, following the degrees of Cr>Cd>>Pb and Pb>Cr=Cd, respectively. Sewage containing heavy metals was one of the major pollution sources. In the commercial district, the average concentrations of heavy metals in the wet season and dry season were in the order of Fe>Pb>Ni>Zn>Cd>Cr and Fe>Pb>Ni>Zn>Cr=Cd, respectively. The concentrations of Cd and Pb in the wet season exceeded the corresponding levels (class Ⅳ), and the degree followed Cd>Pb. Only Pb exceeded the standard in the dry season, with the exceeding standard rate of 60%. Road pollution containing heavy metals was the major pollution source, and heavy metals entered surface water mostly with surface runoff and precipitation. The carcinogenic risk posed by heavy metals in the surface water of the Ningbo industrial district and commercial district was very high, and the carcinogenic risk in the commercial district was much higher than that in the industrial district. The main carcinogen was Cr. Compared to the research results of the research group in 2015, the pollution degree of heavy metals has been greatly reduced. In the future, we still need to give adequate attention to the prevention and control of heavy metal pollution in surface water in Ningbo. |
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