The Present Situation And Risk Assessment Of Heavy Metal Pollution In Road Soil And Dust Of Fujian Triangle Agglomeration

Soil heavy metal pollution is characterized by its concealment and lagging,persistence and complexity,accumulation and locality,irreversibility and intractable rationality.Dangerous and vulnerable to neglect.With the progress of urbanization,the surface hardening area has been enlarged,and the road soil has become an important part of the soil of the Fujian delta urban agglomeration.In order to understand the heavy metal pollution in the soil of Fujian.In this study,the surface soil(0-5 cm)and dust samples were collected along the traffic road of the Fujian triangle.Hg,Cr,Cu,Zn,As and Pb were determined by cold atomic absorption mercury meter and icp-ms.The sources of heavy metals were discussed through correlation analysis and principal component analysis.The soil pollution levels of the road in Fujian were evaluated by nemerow index method potential ecological risk assessment and geoaccumulation index.The spatial distribution of heavy metal pollution in the soil of Xiamen Island was analyzed by means of kriging interpolation method.At the same time,the diffusion range of traffic dust in soil and the heavy metal content in typical soil profile were analyzed.The results are as follows.(1)The degree of heavy metal pollution in Xiamen Island is dust>main road>secondary road,and there is a large variation extent of pollution,and there is man-made pollution.According to the correlation analysis and principal component analysis results,the main source of pollution in the soil of Xiamen Island is the source of traffic and transportation,it's also come from industrial and natural sources.Spatial distribution characteristics of heavy metals as:except Hg in the northwest of the Island of heavy metals were concentrated,Hg mainly for natural source,key distribution area for the Island in the northeast and the south.The soil pollution risk of Xiamen Island is low,most areas are clean,and the areas with serious pollution are located in the Xiangyu port,with serious Cu pollution and Zn and Pb pollution.(2)The content of heavy metals in the intercity soil of Fujian is low.Compared with the urban road surface heavy metal content,intercity surface soil heavy metal content is lower than the main urban area of soil heavy metal content,higher than that of urban trunk road to surface soil heavy metal content.The heavy metal content in the dust of intercity road is lower than that in urban road.The coefficient of variation of heavy metals in the surface layer of intercity surface is large,and there are point sources.The main source of pollution is transportation pollution sources.Pb,Cu and Zn are mainly from transportation.Pollution risk evaluation results show that,the whole ecological hazard risk is low.but may exist pollution index point pollution sources,in geological accumulation index method show that there is a heavy metal accumulation caused by human activity.Compared with the heavy metal content of road soil and dust in urban areas,the main sources of heavy metals in the soil surface near the traffic line in the Fujian triangle area are transportation and the influence of industrial sources is low.(3)Heavy metal content is evident in the typical soil profile table cohesion,within the range of 0 to 10 cm appears to increase with depth to reduce the trend,but the increase to a certain extent in depth(50 cm to 80 cm)and will start to appear to increase with depth in the trend of increase,This is because the heavy metals that congregate on the surface migrate downwards with the leaching of precipitation.From different sampling points,the heavy metal content is industrial zone>old residential areas>farm Land>new residential area>did not utilize the land.The heavy metal content of soil profile in industrial land is the highest,Due to disturbance of human activities,soil stratification is obvious.At the same time,heavy metal content fluctuates violently with depth.The soil heavy metal content in residential land has a positive correlation with the completion time of the community.The longer the community is built,the higher the content of heavy metal elements in the soil.Compared with residential land,Cr and Zn in agricultural land are relatively high,which is due to heavy metals in fertilizers and pesticides used in agricultural production.The heavy metal content of unutilized land is the lowest,which is lower than the soil environmental background value,and the heavy metal content is not changed with the depth because it is not affected by human activities.The content of heavy metals in soil is related to soil pH,organic matter and clay structure.With the decrease of pH,the content of heavy metal ions in soil increased.There is a certain correlation between the organic matter and the content of soil clay and heavy metal.The heavy metal content in profile soil is generally low,but the heavy metal caused by human activities has caused damage to soil quality.In order to ensure the soil safety,the soil heavy metal content is monitored in the process of urban development.(4)Monitoring and early warning and prevention of heavy metal pollution in soil require the cooperation of the whole society.The whole soil pollution monitoring system is constructed,and the soil heavy metal and other pollutants are monitored in real time,and the emergency response plan of soil heavy metal pollution is formulated.Optimize technological innovation,optimize industrial structure and layout,cut off heavy metal from source.In order to develop new and more effective soil heavy metal pollution repair methods,the comprehensive treatment of contaminated soil has been carried out.To play the role of the government,to regulate the emission of heavy metals from the policy and the law,and to prevent and control the soil.