Multimedia Environmental Fate Simulation And Characterization Of Chemical Footprint Of Three Typical Brominated Flame Retardants

Brominated flame retardants(BFRs)are persistent organic pollutants that are widely detected in the environment.It is necessary to assess distribution and fate of BFRs in the multimedia environment,and then evaluate their impact on sustainable development of the human society.In this study,a level III multimedia environmental fugacity model with high spatial resolution was developed,which reflects the natural environment attributes of China.The distribution and fate of 3 typical BFRs in China were predicted and their chemical footprints were assessed.The 3 BFRs include decabromodiphenyl ether(BDE-209),tetrabromobisphenol A(TBBPA)and decabromodiphenylethane(DBDPE),which account for 92.2% of BFRs production in China market.The main research contents and results are as follows:(1)Based on the natural environmental attributes of China,a Level III multimedia environmental fugacity model with spatial differentiation in resolution of 50 km × 50 km was constructed.Concentration and distribution of the 3 BFRs in the atmosphere,water,soil and sediment were predicted.The predicted concentrations were consistent with the measured values.Sensitivity of input parameters and uncertainty of the model were analyzed.Results show that the BFRs concentrations in air and soil are high in the eastern regions such as Beijing,Shanghai,Guangdong and Zhejiang,and are high in water and sediment in the midland such as Gansu,Shaanxi and Shanxi.The BFRs in soil and sediment account for 97.74% of the total,indicating that soil and sediment are main sinks of the BFRs.Environmental attribute parameters(atmospheric residence time,water depth,sediment thickness,etc.)and environmental behavior parameters(octanol/water partition coefficient,organic carbon adsorption coefficient,degradation half-lives in sediment,etc.)of the BFRs have great influence on the model results.Concentrations of the BFRs in soil and sediment have big uncertainties.(2)Chemical footprint characterizes impacts of chemicals on ecology and human's health through occupation of environmental space.Herein a chemical footprint characterization method based on multimedia environmental concentrations was developed to assess chemical footprints of the 3 BFRs in China,and to assess impacts of BFRs on environmental sustainability.The chemical footprints of the BFRs in air and soil media were found to be smaller than volume of the media,and thus the impacts of the BFRs on air and soil is low.However,in nearly 40% of the national geographical areas,occupied water resources space for the 3 BFRs exceeded the local disposable water resources.This phenomenon is mainly concentrated in the southeastern regions of China.The chemical footprints for the BRFs in sediments in nearly 30% of the national geographical areas are larger than the volume of the corresponding media,indicating that the BFRs have a high impact on the local sediment media.To prevent and control health risks of chemicals to human beings and key species of ecosystems,it is necessary to manage risks of chemicals.The 50 km × 50 km resolution multimedia environmental model together with the preliminary calculation method on chemical footprint developed for the three typical BFRs,can be employed to predict environmental fate and footprint of other chemicals after parameter calibration,which has practical application values for the environmental management of chemicals.