中国东部及渤、黄、东海大气全氟辛酸沉降通量研究OA

In view of the current situation where Perfluorooctanoic acid(PFOA)affects the marine en-vironment through atmospheric transport.In this study,based on the improved three-dimensional at-mospheric chemical transport model—the community multiscale air quality model-per/polyfluoroalkyl substances(CMAQ-PFAS)module.Based on the newly established inventories of industrial source at-mospheric PFOA emissions in China for January,April,July and October,2019,the spatial and tempo-ral characteristics of the dry/wet deposition fluxes of atmospheric PFOA in eastern China and the contri-bution of atmospheric PFOA input from the Bohai,Yellow,and East China Seas were systematically investigated.The results show that the annual mean dry deposition flux of total PFOA in the eastern Chinese mainland in 2019(1.20 ng·m-2·d-1)is significantly higher than that in the Bohai,Yellow,and East China Seas(0.31 ng·m-2·d-1),with the share of the particulate state reaching 92.5%(1.11 ng·m-2·d-1).Dry deposition fluxes showed seasonal differences of high winter and low summer,with winter(2.38 ng·m-2·d-1)being 4.5 times higher than summer(0.53 ng·m-2·d-1)in the land region,and winter being 6.9 times higher than summer in the Bohai,Yellow,and East China Seas.The annual mean wet deposition flux of total PFOA in eastern mainland China in 2019 was about 0.40 ng·m-2·d-1,with the particulate and gaseous components contributing 20.0%(0.08 ng·m-2·d-1)and 80.0%(0.32 ng·m-2·d-1).The PFOA wet deposition fluxes in the eastern mainland of China showed summer(0.76 ng·m-2·d-1)>winter(0.67 ng·m-2·d-1)>spring(0.20 ng·m-2·d-1)>significant gradient in fall(0.12 ng·m-2·d-1).The contribution of atmospheric deposition to the PFOA concentration in surface seawater(<30 cm)was characterized by a spatial gradient:in winter,the contributions of the Bohai Sea,Yellow Sea,and East China Sea were 2.3%,1.5%,and 9.3%,respectively,while in summer they decreased to 0.8%,0.3%,and 1.3%.Due to the lowest back-ground concentration of PFOA in seawater,the East China Sea has the highest average contribution rate of atmospheric deposition(5.3%).In contrast,the background concentration of PFOA in the Yellow Sea seawater is relatively high,thus the average contribution rate of atmospheric deposition is the lowest(1.4%).This study reveals that atmospheric deposition,as a pathway for PFOA to enter the Bohai Sea,the Yellow Sea,and the East China Seas,has significant spatial and temporal differences in its con-tribution rate,which provides a scientific basis for assessing the risk of PFOA to the marine environ-ment.