Study On Indicator System For Evaluating The Impact Of Environmental Lead And Cadmium Pollution On Population Health

Part1：Study on indicator system for evaluating the impact ofEnvironmental lead and cadmium pollution on population healthObjective: To establish environmental lead and cadmium pollution health risk evaluationassessment system, lay the foundation for risk assessment methods and risk assessmentmodels, and to provide a theoretical basis for risk management.Methods: Using Literature Review, existing data analysis and panel discussions methods tobuild framework of index system. Applying Delphi method and expert meeting to constructthe index system and using group discussion to revise and improve the index system.Results:(1) Framework of indicator system: According to the definitions and steps of healthrisk assessment and the construction principle of index system, we divided the indexsystem into three groups: pollution sources indicators, the pollution exposure indicators andthe risk characterization indicators.(2)Build the initial index systems which including37indicators for lead and42indicators for cadmium through literature study and groupdiscussion.(3)The composing of consultants: consultants came from the areas ofepidemiology, environmental health and health administration. All of consultants were insenior position and above85percent of the consultants had over20years of work experiences.(4) The results of Delphi consulting: positive coefficients of two rounds ofconsultations were92%and88%, and78%of the experts put written suggestions forindicator system, which meant consultants were very concerned about this project. Thefamiliarity degree and authority coefficients beyond0.8, which proved the consultationresult was credible. After two consultations, harmonious coefficient was good and was ofstatistics significance.The final index system of lead and cadium included30indicators each.Conclusions:(1)As the method of constructing index system is scientific, the indicators canbe used as the basic index of environmental lead and cadmium pollution health riskassessment.(2)Urinary cadmium, cadmium of drinking water, urinary β2-microglobulin,cadmium in the soil and the cadmium in the main food were ranked in the first5place ofcadmium index system.(3)The established index system is based on literature research andexpert advice which lacking of actual data validation, the index system needs to revise andimprove in practice.Part2：A case analysis of Cadmium pollutionObjective：Based on the epidemiological investigation and laboratory analysis of samples oncadmium polluted area of Y city, verifying the index system of scientific and reasonable, andto further improve the index system.Methods：Epidemiological survey and sample collection were applied according to nationalstandards. Dates were analyzed by SPSS18.0.Results：(1)The verification result of index system: analysis of pollution index showed thatsoil and water cadmium contamination existed surrounding the smelter. Compared to that ofthe control area, cadmium levels of soils and waters in the contaminated area weresignificantly higher (p<0.05). The analysis of exposure index showed that human cadmiumintakes mainly through foods (such as rice and vegetables), it was0.0049mg/kg.d averagelyin the contaminated area and0.0029mg/kg.d averagely in the control. The analysis of risk characterization index showed that urinary cadmium, β2-microglobulin, enzyme NAG andthe risk index (HI) of the observed group population were higher than those in the controlgroup (p<0.05). Population bone mineral density (BMD) was on a downward trend with theelevated levels of urinary cadmium.(2)The further verification result of index systemshowed that urinary cadmium and pollution distance, residence time, soil cadmiumconcentration, food cadmium concentration exist obvious dose-response relationships.Relativity between urinary cadmium and β2-microglobulin, enzyme NAG menatdose-response relationship between urinary cadmium and renal damage was confirmed.Conclusions：The most representative indicators of health risk assessment for environmentalcadmium pollution were: urinary cadmium, urinary β2-microglobulin, urinary enzyme NAG,cadmium in mainly food, cadmium in drinking water, cadmium in agricultural soils,cadmium in surface water, risk index. The empirical study of health risk assessment forenvironmental cadmium pollution shows that these indicators can really reflect the actualstatus of the population health in cadmium pollution areas which can provide some guidancefor related field research and relevant authority.