| The essay mainly discussed the exposure assessment methods in risk assessment, particular in probabilistic approaches. The concentrations of chlorate and chlorite in drinking water around one Lake were fitted with each daily exposure and body weight to simulate human exposure using@Risk software. The margin of safety was calculated in order to evaluate the long-term exposure risk to nearby residents in the drinking water.Topic includes:Firstly:The international universal approach of exposure assessment were introduced, including the deterministic approach (point evaluation) and the probabilistic approach, especially the latter. The method of exposure simulation was studied using the Monte Carlo simulation.@Rrisk software was the international tool to assess exposure risk of chemicals in food, and its main principle was to use Monte Carlo simulation methods. The first part is about the applications of@Risk in exposure simulation, including the definition of different variables, the principle of fitting, fitting set, goodness of fit test (chi-squared statistics, Kolmogorov-Smirnov statistics, Anderson-Darling statistics and Root-Mean squared error), the fitted result charts, P values, simulation operation, the results report, analysis and decision.Secondly:The health risks of residents living around one Lake were evaluated according to drinking water pollution research in this area, and finally chlorate and chlorite were selected representative. A total of180houses were visited in12districts and drinking water samples were collected from consumer’s drinking water source with the body weight and daily intake being estimated. Oral exposure and risks were estimated for exposured population by deterministic and probabilistic approaches with a statistical software@Risk. The result showed that there wasn’t any risk to adult while some health risk to children. As a result, we should tank action right now to ensure children’s health. The results showed that the risk of chlorite for adults and children were acceptable, while the risk of chlorate for both adults and children were beyond the acceptable level which should be taken notice and appropriate measures to reduce risk. Especially for children, the risk was higher than adult and should be paid special attention and take measures as soon as possible to protect human health. |
