山东省某小城镇生活垃圾堆积场土壤污染特征及风险评价

Pollution Characteristics and Risk Assessment for the Soil from an Open Dumping Site in a Small Town.Shandong Province

以山东省某小城镇生活垃圾堆积场为研究对象,采集堆场内和边界共17个土壤样品,探析土壤中15种无机与重金属污染物和195种挥发性-半挥发性有机污染物的含量分布特征,通过与国内外不同土壤基准（筛选）值的比较,评估检出重金属的潜在生态风险和健康风险。结果表明,堆场土壤重金属的潜在生态风险普遍处于轻微水平,仅以山东省土壤背景值为参比值时,堆场内土壤因Hg积累而生态风险水平处于强~很强水平;除As外,堆场内土壤中单一重金属的生态风险高于边界。对儿童和成人,堆场土壤的致癌和非致癌风险均在可接受的范围内,不同群体的总非致癌风险差别较小,产生不利健康风险的重金属主要是As、Cr,主要暴露途径为经口直接摄入和皮肤接触。

A total of 17 soil samples were collected from the interior and boundary areas of an open dumping site in a small town in Shandong Province to study the concentration distribution of the pollutants, which include 15 kinds of inorganic pollutants heavy metals and 195 kinds of VOCs-SVOCs. The potential ecological risk and human health risk of the heavy metals detected were evaluated by comparing with the limitation of corresponding criteria, at home and abroad. The results showed that the po tential ecological risk is generally low , except that soils from the interior area are at a strong to very strong level because of ac cumulation of Hg, when the environmental background values of Shandong Province are taken as reference values. The potential ecological risk of a single heavy metal in the soils from the interior area in the site is higher than that from the boundary area except As. Both carcinogenic and non-carcinogenic risks of soils are acceptable for children and adults. The difference in HI between children and adults is negligible. The most harmful heavy metals are As and Cr. The main ways of chronic daily average exposure are ingestion and dermal contact.