Research On The Medium Partitioning Mechanism Of Atmospheric Organophosphate Esters In Polar Regions

Organophosphate esters(OPEs)are widely used chemicals,and their environmental problems are increasingly prominent.Research shows that OPEs can be detected in multi-regional and multi-environmental media around the world,and even reach the level of biological toxicity in some areas,which poses a potential threat to human beings and environment.The atmosphere is an important medium for the regional transport of pollutants,and the polar environment is an important"sink"in the process of pollutant transport.Therefore,it is of great significance to understand the occurrence characteristics,migration and transformation of OPEs in the polar atmospheric environment,and it is necessary to discuss the polar ecological environment and atmospheric environment together,and explore the migration mechanism of OPEs on the global scale,in order to understand the global environmental behavior of emerging organic pollutants.This study is based on the Chinese 34th and 35th Antarctic Scientific Expedition(CHINARE 34 and CHINARE 35),Chinese 9th Arctic Scientific Expedition(CHINARE9),the scientific expedition of Huanghe Station in July 2018 and the Antarctic Great Wall Station and Zhongshan Station winter atmospheric observation,gaseous and particle phase samples were collected.Eleven OPEs were analyzed by HPLC-MS/MS.The results show that the total atmospheric concentrations of OPEs is 231?1,884 pg/m~3 for the CHINARE 9,164?3502 pg/m~3 for the CHINARE 34,73.0?367 pg/m~3 for the Huanghe Station,and 89.5?333 pg/m~3 for the CHINARE 35.Chlorinated OPEs like TCEP and TCPP are predominant in almost all samples,while Tn BP in the Huanghe Station and TPh P and TPe P in the CHINARE 35 are also on a high level.Principal component analysis shows that human activities near the scientific research station may be one of the potential sources of the polar atmospheric OPEs.In this study,the gas-particle distribution,air-seawater exchange and atmospheric deposition processes of CHINARE 9,CHINARE 34,CHINARE 35 and Huanghe stations are discussed in detail,and the distribution behaviors of the atmospheric OPEs in the multimedia polar regions are analyzed.It is found that the Bering Strait,the high latitude area of the Arctic Ocean and the Ross Sea have higher atmospheric deposition fluxes,indicating that the above three areas may be one of the concentration areas of the north and south polar atmospheric OPEs.The atmospheric deposition flux of Tn BP observed at the Huanghe Station and the TPh P observed at the Great Wall Station are extremely higher than that of the navigation samples,indicating that human activities near the scientific research station may be one of the local sources of the polar OPEs.The proportion of the measured atmospheric particle phase of CHINARE 9 increases gradually from the low latitudes to the high latitudes;the proportion of the measured atmospheric particle phase in the Ross Sea area is generally higher.These phenomena indicate that the atmospheric OPEs migrates from the gaseous phase to the particle phase in the high latitudes.The net air-seawater exchange fluxes of CHINARE 9 show a trend of increasing from low latitude to high latitude,however,the exchange fluxes of TCEP,TCPP and other compounds as well as CHINARE 34 show a completely opposite situation.The dry deposition flux of CHINARE 9 and CHINARE 34 shows a trend of increase with the latitude went up,while the longitude does not show a significant difference.However,the temporal distribution characteristics of the polar atmospheric OPEs are not completely clear.Pearson correlation analysis was applied to test the ratio of air temperature,relative humidity,Total Suspended Particulate(TSP)concentrations to the measured proportion of particle-bound OPEs.It was found that temperature may be one of the driving factors affecting the spatial distribution of OPEs in the polar regions.