| In recent years,environmental pollution caused by heavy metals has become more and more serious,and its impact on health has attracted more and more attention.Although heavy metals are elements that exist in nature,due to the rapid development of technology and economy,heavy metal pollution mainly comes from human activities,such as mineral mining,production activities,and the use of metal compounds in daily life.Heavy metal pollution is very difficult to be biodegraded,but on the contrary,it can be enriched thousands or hundreds of times under the magnification of the food chain,and finally accumulate in the human body,causing serious harm to human health.In animals and plants,excessive accumulation of heavy metals can affect the normal function of cells,leading to cancer or apoptosis.The life cycle refers to the whole process of a product from need to design,development,resource extraction,production（material production and product manufacturing,supply）,use,consumption,and finally to the end of life activities（collection,classification,reuse,recycling,waste treatment）.Every product has a life cycle,and all activities or processes in the product life cycle will have an impact on the environment due to the consumption of resources.The complete life cycle,together with its related material and energy flows,is called a product system.After the compilation,listing and preliminary analysis of all environmental exchanges（emissions,resource consumption,etc.）,it is called a life cycle inventory（LCI）.Practitioners often need to calculate and explain the indicator of the potential impact that exchange with the natural environment.Life Cycle Impact Assessment（LCIA）relies on the established life cycle checklist to track the flow of materials and energy throughout the life cycle of a product or service to assess its impact.We have compiled the data for constructing the pollution emission inventory.Based on the above data,we have constructed the pollution emission inventory of Jinan City over the years,and calculated the health toxicity of the compounds discharged into the water and air through the disability adjustment life-year method.Finally,it was discovered that metallic mercury,lead,chromium,and zinc are key substances.Because the evaporation of metallic mercury can cause serious human health risks,this study carried out a model verification analysis for the remaining key substances Pb 2+,Cr 6+and Zn2+.Research purposes:Since the impact of multiple pollutants on the population is not a simple additive relationship,we focus on the core scientific issues of the compound effect under the coexistence of multiple pollutants and the environmental exposure and health hazards of heavy metal pollutants.Study the health hazards of heavy metal pollution represented by lead,chromium,and zinc,and provide preventive and intervention strategies for reducing the health hazards of heavy metal pollution.Research method:1.Using the constructed localized life cycle health toxicity evaluation model analysis,Pb 2+,Cr 6+and Zn 2+are key substances for health toxicity.2.Set an appropriate ion concentration gradient,and measure the cytotoxicity of metal ions by MTT method.3.Single metal ion or multiple metal ions are combined to treat cells,and cell cycle and apoptosis changes are detected by flow cytometry.4.Cells were treated by a single metal ion or a combination of multiple metal ions,and the effect of metal ions on cell mobility was observed.5.Cells were treated by a single metal ion or a combination of multiple metal ions,then the cell inhibition rate was calculated,and the interaction between the ions was analyzed through the software.Research result:1.Pb 2+,Cr 6+and Zn 2+are key substances for health toxicity.2.The cell survival rate was ion concentration-dependent and time-dependent,and the cell survival rate was the lowest when the three metal ions were used in combination.3.After Pb 2+,Cr 6+and Zn 2+were treated for 48h,the cell tails became significantly longer,the tail-to-head fluorescence ratio and tail distance both increased to varying degrees,and the degree of DNA damage increased.The degree of DNA damage in the combined use of two metal ions was significantly higher than that in the single ion treatment group,and the degree of DNA damage was the highest when the three metal ions were combined.4.The combined effect of Pb 2+,Cr 6+,Zn 2+and the three compounds treated the cells for 48h,the cell cycle was arrested in S phase.5.The combined effect of Pb 2+,Cr 6+,Zn 2+and the three compounds inhibit cell migration.6.The combined effect of Pb 2+,Cr6+,Zn 2+and the three compounds promoted cell apoptosis,and the combined effect was significantly higher than that of the single metal ion treatment group.7.The three metal ions have a synergistic effect.As the ion concentration increases,the synergistic effect increases.Among the three metal ions,Cr6+ plays a leading role.Conclusion:1.Using the localized life cycle health toxicity evaluation model analysis,Pb 2+,Cr 6+and Zn 2+ are key substances for health toxicity.2.The cell survival rate was ion concentration-dependent and time-dependent,and the cell survival rate was the lowest when the three metal ions are used in combination.3.Pb2+,Cr6+.Zn2+ cause obvious DNA damage,block the cell cycle in S phase,inhibit cell migration,and promote cell apoptosis.Among them,Cr 6+plays a leading role,and the results were most remarkable when the three metal ions were used in combination.4.The three metal ions of Pb 2+,Cr 6+and Zn 2+have a synergistic effect.The higher the ion concentration,the more obvious the synergistic effect. |
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