| With the increase of the amount of waste incineration treatment,heavy metal pollution caused by waste incineration plants has attracted widespread attention.In this study,8 elements?Cd,Cr,As,Hg,Pb,Cu,Zn and Ni?in the soil and vegetables collected surrounding the municipal solid waste incinerator?MSWI?in North China were determined.The single pollution index,integrated Nemerow pollution index,enrichment factor and potential ecological risk index were used to systematically assess the pollution level of soil heavy metals.The spatial distribution analysis,correlation analysis,principal component analysis?PCA?and absolute principle component score-multiple linear regression?APCS-MLR?model were employed in the contamination source apportionment.The health risk of people living near the MSWI on different functional areas was evaluated.The main results are as follows:?1?The mean concentrations of Pb,Cu,Zn,Cd,Hg and As in soil exceeded the background values indicating heavy metal contamination in soil.The concentrations of Zn and As in vegetables from the garden around MSWI were significantly higher than market vegetables which suggesting a marked impact of emission from MSWI.?2?The single pollution index,calculated according to the soil background values,showed that Cu,Pb,Zn and Hg of soil presented light pollution and As and Cd showed heavy pollution.The integrated Nemerow pollution index indicated the study area was heavily polluted by heavy metals investigated.With the main contributions of Cd and Hg,the ecological risk of study area was relatively high.?3?MSWI had a significant influence on the distribution of soil heavy metals in different distances and the main influence area was within the scale of 1000m of the MSWI.The MSWI,natural source,industrial discharges and coal combustion were identified as the four main sources of soil heavy metals.The Pb,Cu,Zn,Cd and Hg in soil mainly originated from MSWI.?4?The non-carcinogenic risk?1.50,1.68 and 1.92?and carcinogenic risk(9.40×10-3,1.02×10-2 and 3.10×10-3)of adult male,adult female and children all exceeded the acceptable levels,indicating high health risk for public.The primary toxic elements of non-carcinogenic risk and carcinogenic risk were Pb and Ni,respectively.MSWI was the predominate source of non-carcinogenic risk with the average contribution rate of 36.99%and could pose unacceptable carcinogenic risk to adult male,adult female and children(4.23×10-4,4.57×10-4 and 1.41×10-4),which means the impact of MSWI on human health was apparent.The results also showed that natural source was another important origination of health risk and the contribution rates of different functional areas were distinct with high health risk in agricultural areas,residential areas and schools.Adding the land use types in health risk assessment model was reasonable and was recommended in the health risk assessment in polluted areas.The results of this research provided data bases and theoretical support for the site construction and risk prevention of MSWI and were also of guiding significance for the environmental remediation of soil. |
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