成都绕城高速两侧土壤重金属含量测定及健康风险评价

Determination of Heavy Metal Content in Soils on Both Sides of Chengdu City Expressway and Evaluation on the Healthy Risk

成都绕城高速公路属于成都市主要交通干线,为成都市带来巨大经济及社会效益,但是,也不可避免给环境带来污染。因此,研究成都绕城高速两侧土壤污染情况具有重要意义。采用"梅花点法"和"四分法"采集得到成都绕城高速公路两侧表层土壤(0~20cm)样品24个,电感耦合等离子体质谱法(ICP-MS)测得土壤样品中铬(Cr)、镍(Ni)、铜(Cu)、锌(Zn)、砷(As)、镉(Cd)和铅(Pb)含量的平均值分别为46.81、192.48、28.24、111.79、4.74、2.79和51.68 mg/kg。讨论重金属分布特点,采用污染指数法对土壤重金属污染进行评价;应用美国环境保护局风险评价方法对成都绕城高速两侧土壤重金属通过直接摄入、皮肤接触和呼吸摄入3种途径进入人体的危害进行了风险计算和初步评价。结果表明:成都绕城高速公路两侧土壤未受到重金属污染(Ni除外),且7种重金属对人体均不存在明显健康风险。

Chengdu city expressway is Chengdus main traffic trunk road, and creates great economic and social benefits. However, it inevitably brings pollution to the environment. Therefore, it is of great significance to study the soil pollution on both sides of Chengdu city expressway. Twenty-four topsoil （0 ？20 cm） samples were collected alongside Chengdu city highway, using the “plum shaped arrangement method” and “point-quarter sampling method” . The concentrations of Cr, Ni, Cu, Zn, As, Cd and Pb in soil were tested by ICP-MS. The average contents were 46. 81, 192. 48, 28. 24, 111. 79, 4. 74, 2. 79 and 51. 68 mg/kg. Pollution index method was applied to evaluate soil environmental quality alongside the Chengdu city highway, and the distribution characteristic of heavy metal was discussed. Preliminary assessment of health risks caused by ingestion from eating, skin contacting and breathing was performed through a method from US EPA. The results showed that the soil alongside Chengdu city highway was not polluted by heavy metals except Ni, and the health risk to human beings caused by heavy metals was not obvious.