Heavy Metals In Soils And Pine Needles From Typical Cities In Northeast China

The pollution of heavy metals is a widespread environmental problem all over the world. The environmental quality of cities is one of the important factors to the health of residents. Soils and pines needles were analysis to survey the heavy metal contamination in the main cities of northeast China. Dalian was introduced as a model in this studies, the level of heavy metal pollution was assessed by the integrated pollution index and potential ecological risk assessemnts. The sources of heavy metals were identified by the correlation analysis and cluster analysis. The main results were presented as follows.(1) Pine needles are a good bioindicator plant for heavy metal in environmet. By analysis of pine samples, the integrated pollution index in the most of cities in northeast China were not high, except of Shenyang, which suggested that heavy metal pollution was not serious. Most of heavy metal concentrations in pine needles were not beyond the critical level, but it was possible that lead pose the potential threat in Dalian. Correlation analysis and cluster analysis identified that traffic was thepossible source for Pb, Zn, Cu, Ba, V, Fe, Ti, Cr, K, Na and Y, and other metals were from the soil.(2) 78% cities in 14 cities of northeast region were polluted slightly by heavy metals according to the integrated pollution index. High concentration of Cd in some cities might be harmful for human health. The ecological risk was low in most cities of northeast China, except Shenyang. The range of total concentrations of Zn, Pb, Cu, Cd, Cr, and Cr in soils in Dalian was 47.5 ～ 360, 9.4～97.1, 13.2～72.9, 0～8.68, 13.2～55.1, 2.0～41.2 mg/kg, respectively. The results of integrated pollution index and the potential ecological risk assessment were indicated that Cd was the main pollutant in soil in Dalian, and pollution of Zn and Pb was serious in some locations. Cluster analysis demonstrated that the distribution of heavy metal in soils agreed with the distribution of industrial, traffic, residential of Dalian. Heavy metal concentrations in traffic and industrial centre were higher, while those in rural area were lower.By the investigation of soils and pine needles, it was shown that the level of heavy metals was not high in most cities in northeast China. Cd and Pb could be the potential environmental risk in some cities. Shenyang was the city with the most serious pollution. It was suggested that some measures should be taken to control the pollution.