Research On Heavy Metal Pollution Of Soil And Dust In Baoji Changqing Industrial Park

At present,environmental pollution accidents happen frequently at home,especially for heavy metal pollution events,which cause severe harm to ecological environment and human health.In 2009,thousands of children blood lead exceeding the standard was reported in Changqing Town,Fengxiang County,Baoji City,Shannxi Province,China.In this study,heavy metal pollution of soil and dust in Changqing Industrial Park of Baoji was systematically investigated for the first time.The research contents include physicochemical properties of soil and dust,content level,distribution characteristics,environmetal sources,speciation and movement characteristics,analysis of pollution level,ecological harm and health risk of heavy metals,and comparison of heavy metal pollution between soil and dust.The objectives of this study are(1)to detect content level and to analyze distribution characteristics of heavy metals of soil and dust in Changqing Industrial Park,Baoji;(2)to analyze pollution level and environmental sources of heavy metals of soil and dust in Changqing Industrial Park,Baoji;(3)to analyze ecological risk and health risk of heavy metals of soil and dust in Changqing Industrial Park,Baoji;and(4)to provide some supports for risk prevention,environmental management and government decision.Main results and conlusions:1.Heavy meltal content and distribution:Most of heavy metals analyzed were accumulated in soil and dust of Changqing Industrial Park of Baoji,especially for Cr,Cu,Hg,Pb and Zn of dusts,which were 25,8,4,60 and 25 times,respectively,of soil bachground values of Shaanxi and China.Contents of heavy metals in soil(e.g.Cu,Pb and Zn)and dust(e.g.As,Cu,Hg,Pb and Zn)around Pb-Zn smelting plant were higher than those around coal-fired power,especially for As,Cu,Hg,Pb and Zn in dust around Pb-Zn smelting plant,which were 2,6,3.3,2,9.3 and 6.0 times,respectively,of that around coal-fired power.In soil,Cu,Hg,Pb and Zn were distributed in the northern and southern of Pb-Zn smelting plant,whereas Cr was in the western of coal-fired power.In dust,Cu,Pb and Zn were concentrated in the western part of Pb-Zn smelting plant,and Cr was also in the western of coal-fired power,and Hg was in the east and west parts of Pb-Zn smelting plant.As,Pb and Zn were riched in surface soil around Pb-Zn smelting plant;Cr was accumulated in surface soil around coal-fired power;Cu and Hg were concentrated in surface soil around Pb-Zn smelting plant and coal-fired power.2.Heavy metals pollution level and sources:Soil in Changqing Industrial Park of Baoji was contaminated by moderate Hg and slight Pb,and was slightly polluted by Co,Cr,Cu,Sc and Zn in some regions.In soil,Cu,Pb and Zn were mainly from Pb-Zn smelting;Hf,Zr,Th,U,Ti,Y,Co and Cr mainly came from bed rock;and other heavy metals had a natural and anthropogenic mixture source.In dust,pollution level of As,Co,As,and Y was slight;Cu and Hg belonged to moderate pollution level;pollution degree of Cu and Zn was heavy;Pb pollution arrived at a severe level,some regions had a slight pollution of Ba,Cs,Ga,Ni,Sc and V.Pb,Y,Ga,Zn and Ni of dusts were mainly from Pb-Zn smelting,Ti,Zr,Hf,Th,U,Sc and Cs of dusts mainly came from soil dust,and other heavy metals had a natural and anthropogenic mixture source.3.Heavy metal environmental risk:In soil,the proportion of the unstable part of Mn,Pb and Co was higher,and had a higher potential ecological harm.Ecological risk of heavy metals in soil belonged to a moderate level.Among them,Hg had a heavy ecological harm,and ecological risk of As,Cr,Cu,Pb and Zn was slight.Heavy metals in soil could not lead to no-cancer risk,while cancers risk of As exceded the standard limit of US EPA(10-6).In dust,the proportion of the unstable part of Pb,Zn,Co,Mn and Cu was higher,and had a higher potential ecological harm.Ecological risk of heavy metals in dust arrived at a severe level,ecological harm of Hg and Pb arrived at a severe level,ecological harm of Cr,Cu and Zn belonged to a moderate level,and As had a slight ecological harm.Cr and Pb in dust could cause no-cancer risk to children,and cancer risk of As and Cr was higher than the standard limit of US EPA.4.In Changqing Industrial Park of Baoji,dust was main environmental pollution factor,which might cause a severe harm to ecological environment and human health.Content level,transfer ability,pollution level,and potential ecological and health risk of heavy metals in dust were higher than that in soil.In dust,Pb and Cr could cause non-cancer risk to children,cancer risk of As and Cr were higher than the standard limit of US EPA.Therefore,more attentions should be paid to them by people and government.The result was different from the previous report that lead level had a slight increased trend in local soils and was not abnormal in local water body.Characteristics and Innovations:Characteristic 1:Changqing Industrial Park of Baoji was selected as research regions;soil and dust of Changqing Industrial Park were main research object;region and object of research were typical.Characteristic 2:soil combined with dust;research contents were systematical;research methods were reasonable.Conclusion Innovation:Content,distribution,sources,speciation and mobility of heavy metal in soil and dust of Changqing Industrial Park of Baoji were systematically studied for the fisrt time and ecological risk and health risk were analyzed.The results showed that dust was main pollution factor:ecological risk of heavy metals of dust belonged to a sever level;Cr and Pb in dusts could cause no-cancer risk to children and cancer risk of As and Cr was higher than the standard limit of US EPA.