Research On Soil Heavy Metal Ecological Risk Assessment And Health Risk Assessment Based On Monte Carlo Simulation

There are many influencing factors for the ecological risk and health risk of heavy metal pollution in the soil,so there are uncertainties for the risk.The article takes the leftover site of a relocated lead-acid battery plant as the research object.The Nemero index method and the geological accumulation index method are used to analyzed and evaluated the current situation of heavy metal pollution based on sampling heavy metal Cr,As,Pb,Cu,Zn content in the site.Monte Carlo simulation was introduced to combine it with the Hakanson ecological hazard index method and the health risk assessment model recommended by the "Technical guidelines for risk assessment of soil contamination of land for construction " to develop uncertainty risk assessment model for the heavy metal ecological risk assessment and health risk assessment of the site soil.The model was applied to ecological risk and health risk assessment of a relocated lead storage battery plant.The main conclusions are as follows:(1)The Nemero index indicates that the heavy metal pollution of the study site soil has reached a serious pollution level,of which the heavy metal Cr is moderate pollution,As,Pb,Cu are heavy pollution,and Zn is light pollution;The geological accumulation index indicates heavy metal pollution has reached a middle pollution level,of which heavy metals Cr and Zn are light pollution,As and Cu are moderate pollution,Pb strong pollution-very strong pollution.Both evaluation methods indicate that the pollution of heavy metal Pb in the soil of the study site needs to be highly concerned.(2)The evaluation of the ecological risk of heavy metal in the soil of the study site using the uncertainty risk assessment model indicates that the probability of the heavy metal in the soil of the research site at low,medium,high and high ecological risk levels is 7.56%,28.97%,49.44%,14.03%,respectively;the sensitivity of heavy metal Pb to the ecological hazard index is 99.7%,and heavy metal Pb is the main heavy metal pollution factor for the ecological risk of heavy metals in the site soil.The evaluation of the health risk of heavy metal in the soil of the research site by using the uncertainty risk assessment model indicates that the heavy metal in the site has a non-carcinogenic health risk to the population in the study area,and The probability of non-carcinogenic health risks of five heavy metals of Cr,As,Pb,Cu,Zn for the people in the district is: 100%,90.22%,99.17%,0,0,respectively,and heavy metal Pb plays a leading role in the non-carcinogenic health risk of the people in the study area,and the sensitivity reaches 94.4%;The soil heavy metals in the study area have carcinogenic health risks to children and adults in the study area,and the probability of the researched heavy metals of Cr,As has carcinogenic health risks to children and adults in the study area has reached 100%.Heavy metal of Cr play a major role for children and adult carcinogenic health risks with sensitivities of 92.9% and 98.7%,respectively.(3)The constructed uncertainty risk assessment model evaluates the ecological risk and health risk of soil heavy metals,not only provides the pollution risk level,but also provides the probability of the risk status and the impact of heavy metals on ecological risk and contribution situation to health risk,which effectively reduces the uncertainty in the risk assessment of soil heavy metal pollution,so it helps to make risk decision-making more scientific and reasonable,the entire operation procedure is simple,and the feasibility is strong.