Investigation And Risk Assessment Of Heavy Metals Pollution In Soil On Both Side Of Some Roads In Beijing

With the fast development of economy and society, people’s living standard has beenimproving and the traffic environment has become very complex. As a essential component andprecious resource in the environment, soil is closely related to human being’s survival. It not onlyprovides people with vigorous productivity, but also endures various pollutions imposed byanthropic activities.20samples from10sampling sites were collected from both sides ofChaoyang Road, Chaoyang Distirct, Beijing, so as to analyze total amount of heavy metals anddistribution of content of their existing form. The results obtained from this research indicate thatthe residual form of Cr, Ni, Cu, Zn and Cd accounts for the highest proportion of total amount,with oxidized form, acid extracted form, reduced form and soluble form being less in turn, whilethe proportion of existing form Pb, from the highst to the lowest, is oxidized form, residual form,reduced form, acid extracted form and soluble form. The contamination of heavy metals in soilwas assessed by using four methods—geoaccumulating method, assessment of potentialecological risk, RAC risk assessment and ratio of secondary phase and progenetic phase. Withrespect to the geoaccumulating method, which is based on total amount, the contamination is Cd＞Ni＞Zn＞Cu＞Cr＞Pb, while the potential contamination by assessment of potential ecologicalrisk is Cd＞Ni＞Cu＞Pb＞Cr＞Zn. As for the RAC risk assessment based on morphology, thebiological availability is Cd＞Ni＞Zn＞Cu＞Pb＞Cr, while the potential biological availabilityobtained from the ratio of secondary phase and progenetic phase is Pb＞Ni＞Zn＞Cd＞Cu＞Cr.Apart from the risk assessment, the restoration method of heavy metal contamination is presentedfor reference.