丽江高背景区土壤-蔬菜中铬含量及健康风险评价

Chromium Content and Health Risk Assessment of Soil-Vegetables in High Background Area of Lijiang City

为了解丽江市蔬菜地土壤和对应蔬菜中铬(Cr)含量状况及健康风险,在丽江市选择4个蔬菜主产区县,同步采集35对土壤样品和蔬菜样品,系统分析了Cr累积状况及健康风险。结果表明:(1)丽江市蔬菜地土壤Cr平均含量为213.3 mg/kg,是云南省土壤Cr环境背景值的2.91倍,超过土壤污染筛选值,菜地土壤样品Cr超标率37.1%,主要分布于古城区和玉龙县,且蔬菜样品中古城区和玉龙县也分别处于中度污染和重度污染水平;(2)不同类别蔬菜对Cr的吸收富集能力不同,土豆、莴笋、蚕豆的富集能力较强,而菠菜的富集能力相对较弱;(3)健康风险评价显示,华坪县和永胜县蔬菜Cr不会对健康造成风险,而古城区和玉龙县居民每人每天从蔬菜中摄取的Cr含量超出了安全上限,存在潜在健康风险。由此可见,对于Cr土壤地球化学背景值高的区域,其食物链风险不容忽视。

To understanding the chromium(Cr)content status and health risk of vegetable plot and corresponding vegetables in Lijiang City,4 counties with large area of vegetable planting were selected and 35 pairs of soil and vegetable samples were collected using point-to-point collaboration to systematically analyze the status of Cr accumulation and health risk.The results showed that:(1)The average content of Cr in vegetable soil in Lijiang City was 213.3 mg/kg,which was 2.91 times the background value of soil Cr environment in Yunnan Province,and exceeded the screening value of soil pollution.The Cr exceeded standard rate in vegetable soil was 37.1%,mainly distributed in Gucheng District and Yulong County.The vegetable samples in Gucheng District and Yulong County were both at the level of moderate pollution and heavy pollution,respectively;(2)Different types of vegetables had different absorption and enrichment capacity for Cr.Potatoes,lettuce and broad beans had stronger ability to accumulate Cr,while spinach was relatively weaker;(3)Health risk assessment showed that vegetable Cr in Huaping County and Yongsheng County did not pose a risk to health,while the daily intake of Cr from vegetables in Gucheng District and Yulong County exceeded the safety limit,indicating a potential health risk.Therefore,the food chain risks in regions with high background values of Cr soil geochemistry cannot be ignored.