Anthropogenic Dust PM_2.5 Emissions And Their Impacts Over East Asia

Dust aerosol is one of major component of aerosols and plays an important role in climate system and ecological environment.Dust aerosols can be categorized as natural and anthropogenic dust.Dust emissions induced by anthropogenic activities account for 30%⁷0%of total dust emissions,whose contribution to global dust loading should not be neglected.East Asia,as the largest anthropogenic dust emission source region,has suffered the great growth in population,rapid development of industry,intensified urbanization and drastic land use changes.Therefore,it is of great significance to investigate the anthropogenic dust over East Asia.This paper utilized various data sets to explore the direct anthropogenic dust emission over East Asia,and investigated the impact of direct anthropogenic dust emission on air quality based on WRF-Chem model.Moreover,the premature mortality burden induced by direct anthropogenic dust PM_2.5.5 exposure was estimated based on the traditional epidemiological relation approach.The main results are as follows:?1?Fugitive road dust?FRD?particles emitted by traffic-generated turbulence are an important contributor to urban ambient fine particulate matter(PM_2.5).Especially in urban areas of developing countries,FRD PM_2.5.5 emissions are a serious environmental threat to air quality and public health.FRD PM_2.5.5 emissions have been neglected or substantially underestimated in previous study,resulting in the underestimation of modeling PM concentrations and estimating their health impacts.This study constructed the FRD PM_2.5.5 emissions inventory in a major inland city in China?Lanzhou?in 2017 at the high-resolution?500 m×500 m?,and investigated the spatiotemporal characteristics of the FRD emissions in different urban function zones,and quantified their health impacts.The FRD PM_2.5.5 emission was approximately1141±71 kg d^-1,accounting for 24.6%of total PM_2.5.5 emission in urban Lanzhou.Spatially,high emissions exceeding 3×10⁴?g m^-22 d^-11 occurred over areas with smaller particle sizes,larger traffic intensities,and more frequent construction activities.The estimated premature mortality burden induced by FRD PM_2.5.5 exposure was 234.5deaths in Lanzhou in 2017.Reducing FRD emissions are an important step forward to protect public health in many developing urban regions.?2?The direct anthropogenic dust PM_2.5.5 emission scheme for East Asia is developed based on land cover,population,land cover,GDP,population,human foot,global desertification vulnerability index and precipitation.The characteristics of anthropogenic activity and direct anthropogenic dust PM_2.5.5 emission in different urbanization areas are studied.The average monthly direct anthropogenic dust PM_2.5emission flux in East Asia is 72834.4 g km^-22 month^-1,with a monthly emission of1429.09 tons.High value areas are concentrated in Beijing,Tianjin and Hebei,India,Pakistan and Bangladesh.The average monthly direct anthropogenic dust PM_2.5emission fluxes are as high as 187.9 kg km^-22 month^-1,with total emissions of 72.9 ton month^-1,and in the medium stage of urbanization area are 155.6 kg km^-22 month^-1,with total emissions of 224.1 ton month^-1.The direct anthropogenic dust PM_2.5.5 emission fluxes are the smallest in summer and the highest in winter.The largest difference of60 kg km^-22 month^-11 between winter and summer is located in India and Bangladesh.The contribution of direct anthropogenic dust PM_2.5.5 emission to total PM_2.5.5 emissions can not be ignored.In New Delhi and Beijing,the proportion of direct anthropogenic dust emission in PM_2.5.5 emission is 28.0%and 23.1%,respectively,which is the third largest emission source after energy consumption and activities of residents.?3?WRF-Chem model is applied to simulate the spatial characteristic of anthropogenic dust PM_2.5.5 over East Asia,associated with observations.The impact of anthropogenic dust PM_2.5.5 on air quality and public health over different climate regions are investigated based on arid index.The WRF-Chem model considering anthropogenic dust emission can reproduce the spatial distributions of AOD and PM_2.5,and improve the results over India and East China effectively.Anthropogenic dust AOD are 0.2,0.15 and 0.1 in India,Beijing-Tianjin-Hebei and Sichuan Basin,respectively.There is a spatial gradient in anthropogenic dust AOD,with increase from hyper-arid region towards humid region.The regional average concentration of anthropogenic dust PM_2.5.5 is up to 11.5?g m^-33 in the semi-arid region,and also above8?g m^-33 in the humid and arid regions.The premature mortality burden due to exposure to anthropogenic dust PM_2.5.5 is estimated at 610.5×10³ persons in East Asia in 2014.