Combining Dynamic Material Flow Analysis With Ecological Risk Assessment Of Synthetic Chemicals

Di(2-ethylhexhyl)phthalate(DEHP)is a high production volume chemical,which is often used as plasticizer.DEHP is an environmental endocrine disruptor.Long-term exposure to DEHP would pose a threat to human and ecological health.DEHP is easy to release to the environment in the process of production,product processing,use,transportation and waste disposal.The management of DEHP requires the evaluation of its material flow,environmental level,and ecological risk in the economic system.In this study,dynamic material flow analysis(DMFA)of DEHP was conducted by investigating the full lifecycle data of DEHP in China.Based on the results of DMFA,the environmental level of DEHP was predicted by establishing a multimedia environmental model.The main research content and results are as follows:The dynamic flow,stock and emissions of DEHP in China from 1956 to 2017 were quantified by DMFA.The results show that the flow and stock of DEHP in China were increasing year by year;The accumulation of DEHP was the highest in the use phase;The two main end flows of DEHP were towards soil and landfilling phase;The proportion of DEHP flows towards landfilling phase were the largest and that towards DEHP recycling phase was the smallest among all waste disposal methods;Among DEHP air emissions,the indoor use of DEHP-containing products accounts the largest;DEHP emissions from recycling phase were the smallest;After 2000,the per capita stock and emissions of DEHP in Japan showed a downward trend,which still increased year by year in China.Based on the DEHP emission rate obtained by DMFA,a level III multimedia environmental model based on fugacity was established to predict the environmental concentration of DEHP in China from 1956 to 2017.The results showed that the concentration of DEHP in atmosphere,water,soil and sediment increased year by year;DEHP concentration in sediment was the highest;Predicted value of the model was a conservative estimation of DEHP average environmental level in China.According to the annual average concentration of DEHP in water,soil and sediment predicted by the multimedia environmental model,the ecological risk of DEHP in water,soil and sediment to key species of ecosystem in China was assessed by two methods:assessment factor and species sensitivity distribution.The results show that the ecological risk of DEHP in China was increasing year by year;After 1975(assessment factor)and 1991(species sensitivity distribution),respectively,DEHP posed ecological risk to organisms living in sediments,surface water and soil in China;The ecological risk of DEHP in sediment and surface water were higher than that in soil.In this study,DMFA,multimedia environmental model and risk assessment model were coupled to quantify the stock,material flow,environmental release rate,concentration in natural environment and corresponding ecological risk of DEHP in China's economic system.This multi-model coupling method is rarely used in the study of chemical ecological risk assessment and management.The method of this study can be applied to other chemicals and help to make up the gap of data needed in chemical management.