Characteristics and risk assessment of heavy metal contamination in agricultural soil surrounding typical heavy metal regulatory enterprises in Sichuan province in 2021
Objective To strengthen the supervision of regional contaminants discharge enterprises and implement precise control of soil contamination.Methods Taking typical heavy metal regulatory enterprises in Sichuan province as the research object,83 farmland soil surface samples around 17 typical heavy metal regulatory enterprises in 7 industries in Sichuan province were collected from July to September 2021.The pH and Cu,Zn,Pb,Cd,Ni,Cr,Hg and As contents in the soil were determined.The contamination characteristics,potential ecological risks and health risks were evaluated by contamination index method,comprehensive potential ecological risk index method and human health risk assessment model.Results The unqualified rate of heavy metals in farmland soil ranked as Cd(30.1％)＞Zn(15.7％)＞Cu(9.64％),Pb(9.64％),Cr(9.64％)＞Hg(1.2％),and the unqualified rates of industries were as follows:chemical raw materials and chemical products manufacturing industry(75.0％)＞non-ferrous metal smelting and rolling processing industry(66.7％)＞ferrous metal smelting and rolling processing industry(60.0％)＞electrical machinery and equipment manufacturing industry(50.0％)＞petroleum,coal and other fuel processing industry(21.4％)＞power,heat production and supply industry(14.2％).The single contamination index of heavy metals in farmland soil was Cd(6.31)＞Zn(1.35)＞Pb(0.71)＞Cu(0.65)＞Cr(0.62)＞Ni(0.42)＞As(0.34)＞Hg(0.13),and the comprehensive contamination level of heavy metals in farmland soil around each industry was as follows:non-ferrous metal smelting and rolling processing industry(62.06)＞ferrous metal smelting and rolling processing industry(3.61)＞electrical machinery and equipment manufacturing industry(1.91)＞petroleum,coal and other fuel processing industry(1.54)＞chemical raw materials and chemical products manufacturing industry(1.49)＞power and heat production and supply industry(0.91)＞ecological protection and environmental governance industry(0.71).The average contribution rate of the comprehensive potential ecological risk index(RI)in the study area was Cd(77.7％)＞Hg(17.9％)＞Pb(1.2％)＞As(1.1％)＞Cu(0.8％)＞Ni(0.7％)＞Zn(0.3％),Cr(0.3％).The comprehensive potential ecological risk index(RI)of industries showed the following trends:non-ferrous metal smelting and rolling processing industry(2 532)＞chemical raw materials and chemical products manufacturing industry(535)＞ferrous metal smelting and rolling processing industry(475)＞electrical machinery and equipment manufacturing industry(286)＞petroleum,coal and other fuel processing industry(268)＞ecological protection and environmental governance industry(217)＞electricity and heat production and supply industry(175).The non-carcinogenic risk of heavy metals in soil was HQois(oral intake)＞HQdcs(dermal contact)＞HQpis(inhalation)for both adults and children,the total non-carcinogenic health risk index(HI)of 8 heavy metals to adults was less than 1,and the total non-carcinogenic health risk index(HI)of children in 4 industries(chemical raw materials and chemical products manufacturing industry,ferrous metal smelting and rolling processing industry,non-ferrous metal smelting and rolling processing industry,electrical machinery and equipment manufacturing industry)was greater than 1.Conclusion The production activities of enterprises in the investigated area have caused different degrees of heavy metal contamination and ecological risks to the surrounding farmland soil.The contamination level of Cd element is the highest and the ecological risk contribution is the largest.The production activities of related enterprises represented by non-ferrous metal smelting and rolling processing industry have caused serious heavy metal contamination and extremely high ecological risks.Heavy metals in farmland soil in the study area will cause a greater risk of non-carcinogenic diseases to children under the combined effects of three exposure pathways.As and Cr are the main factors causing non-carcinogenic risks,and the risk of oral intake should be prevented.
Surrounding the enterpriseFarmlandSoilHeavy metalsPollution characteristicsRisk assessment
万方数据
维普
