医疗废物焚烧炉运行前后5年周边土壤重金属对比分析研究

Levels of heavy metals in soil around a medical waste incinerator: Comparison after five years of operation

为研究医疗废物焚烧炉对周边土壤中重金属含量的影响,对某典型焚烧厂周围土壤进行了运行前和运行5年(2007—2012年)后重金属含量的采样分析研究.共采集20个土壤样品、2个飞灰样品,并对其中砷(As)、镉(Cd)、铜(Cu)、汞(Hg)、镍(Ni)、铅(Pb)、锑(Sb)、钒(V)、锌(Zn)共10种重金属的含量进行了测定.结果显示,除Pb外,其余金属元素含量都有不同程度的升高.主成分分析表明,医疗废物焚烧厂并不是该区域土壤中重金属的唯一污染来源,还存在其它潜在污染源.健康风险评估结果显示,砷(As)在非致癌及致癌风险评估中都明显超标,必须严格控制砷排放,降低砷在环境中的含量.

In order to investigate the impact of medical waste incinerator （MWI） on the heavy metal deposition in ambient soil, a comprehensive soil sampling and measurement program concerning heavy metals around a typical MWI plant in cases of pre-service and post-service after five years （2007- 2012） was conducted. 20 soil and 2 fly ash samples were collected, and 10 heavy metals, including arsenic （As）, cadmium （Cd）, copper （Cu）, mercury （Hg）, nickel （Ni）, lead （Pb）, antimony （Sb）, vanadium （V） and zinc （Zn）, were tested. Experimental results indicate that the concentrations of all tested metals except Pb have the increasing trend. The principal component analysis shows that medical waste incinerator is not the only source of heavy metals in ambient soil. Other potential pollution sources may exist in this studied region. Health risk assessment shows that Arsenic concentration is obviously excessive in both non-carcinogenic and carcinogenic risk assessments. This point out that Arsenic emission should be strictly controlled to prevent its deposition in the environment.