锌冶炼区耕地土壤和农作物重金属污染状况及风险评价

发布时间：2018-06-05 09:24

本文选题：锌冶炼 + 耕地土壤　；参考：《环境科学》2017年10期

【摘要】：对贵州省某典型锌冶炼区耕地土壤和主要谷类农作物(稻米、玉米和小麦)进行取样调查,测定了土壤和谷类农作物中重金属Pb、Cd、Zn和Cu的含量,采用单因子污染指数和综合污染指数法评价了土壤和作物籽粒中重金属的污染状况,并分别采用潜在生态风险指数(RI)和危险商(HQ)法评价了土壤重金属污染的潜在生态风险程度和作物中重金属对成人和儿童的健康风险.结果表明:(1)冶炼区耕地土壤受到了重金属不同程度的污染,污染程度排序:玉米地水稻田小麦地,且CdCuZnPb,内梅罗综合污染指数分析结果表明,玉米地污染程度为重污染,水稻田和小麦地为轻污染,且均以Cd对综合指数的贡献最大;(2)土壤Cd存在极强生态风险,4种重金属潜在生态危害大小顺序为:CdPbCuZn;生态风险指数(RI)研究结果表明,研究区处于轻微、中等、强的和很强的生态风险程度的采样点比例分别为1.41%、21.1%、35.2%和42.3%.(3)冶炼区农作物稻米中重金属Pb、Cd、Zn、Cu的平均含量分别为0.145、0.017、16.97和2.704 mg·kg~(-1);玉米中重金属Pb、Cd、Zn、Cu的平均含量分别为0.094、0.055、26.81和4.464 mg·kg~(-1);小麦中重金属Pb、Cd、Zn、Cu的平均含量分别为0.048、0.085、35.37和5.426 mg·kg~(-1).(4)研究区稻米、玉米和小麦均存在重金属超标现象,重金属污染程度为小麦最重,稻米和玉米的污染程度相当,稻米和玉米污染等级均为安全,小麦处于警戒线.(5)各重金属元素每日摄入量均低于美国环保署的参考暴露剂量,安全性较好,但食用该区域谷类农作物引起复合重金属污染对成人和儿童均存在健康风险.(6)耕地土壤重金属含量与谷类农作物可食部分重金属含量间无明显相关性.
[Abstract]:The contents of heavy metals (Pb, CD, Zn and Cu) in soils and main cereal crops (rice, corn and wheat) in a typical zinc smelting area in Guizhou Province were investigated. The pollution status of heavy metals in soil and grain was evaluated by single factor pollution index and comprehensive pollution index method. The potential ecological risk degree of soil heavy metal pollution and the health risk of crop heavy metals to adults and children were evaluated by Ri and HQs respectively. The results showed that the cultivated soil in the smelting area was polluted by heavy metals to different degrees. The order of pollution degree was as follows: maize paddy field, wheat field, and CdCuZnPb, Nemero comprehensive pollution index. The results showed that the pollution degree of cornfield was heavy pollution. In paddy field and wheat field, the pollution was light, and CD contributed the most to the comprehensive index. (2) CD in soil had extremely strong ecological risk. The order of potential ecological harm of four heavy metals was: 1 CdPbCuZn.The ecological risk index (RII) showed that the study area was slight. Medium, The ratio of sampling sites with strong and very strong ecological risk was 1.41and 21.1cm = 35.2% and 42.3%, respectively.) the average contents of heavy metal Pb ~ (2 +) CD ~ (2 +) Zn ~ (2 +) in crop rice in smelting area were 0.145 0. 017 ~ 16. 97 and 2.704 mg 路kg ~ (-1) ~ (-1), respectively, and the average contents of heavy metal in maize were 0. 094% and 4.464 mg 路kg ~ (-1) ~ (-1) ~ (-1), respectively, and that in maize were 0.094% and 4.464 mg 路kg ~ (-1) ~ (-1), respectively. The average contents of Zn and Cu in the middle heavy metal PbPbcdcdcdczn were 0.048% 0.085 ~ 35.37 and 5.426 mg / kg ~ (-1) ~ (-1) ~ (1) ~ (4), respectively. Heavy metal pollution was the most serious in wheat, rice and maize were the same, and rice and corn were safe. The daily intake of each heavy metal element in wheat was lower than the reference exposure dose of EPA, and the safety was better. However, there was no significant correlation between heavy metal contents in cultivated soil and edible parts of cereal crops.
【作者单位】：贵州省环境科学研究设计院;环境保护部华南环境科学研究所;
【基金】：环境保护公益性行业科研专项(201409042) 贵州省重大科技计划项目([2012]6014) 贵州省科学技术基金项目([2013]2163)
【分类号】：X173;X53;X820.4

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