An Emission Inventory Of Polycyclic Aromatic Hydrocarbons In China

Polycyclic aromatic hydrocarbons(PAHs)are persistent organic pollutants,which threaten human's health.They exist in particles and(or)in gas phase and can be carried by air current for long-distance transportation,leading to regional pollution.PAHs are mainly derived from anthropogenic emissions.An anthropogenic emission inventory of PAHs is of primary importance to understand pollution status,formation mechanism and evolution and to further eliminate and control PAHs pollution.In China,the anthropogenic emission amounts of PAHs are great.Therefore,the development,update and improvement of a nationwide PAHs emission inventory is needed.In this work,the emission inventory of 16 U.S.EPA priority PAHs from 33 major anthropogenic sources categories in China in the year of 2012 was compiled.The emission amounts of PAHs were estimated based on emission factors and emission-related activities.The spatial resolution was enhanced to the county level using spatial interpolation method.And the uncertainty of the emission inventory was quantified using Monte Carlo method.The total emission of PAHs was 81179 tons in 2012.In China,PAHs were emitted predominantly from diesel vehicle emissions(28.6%),followed by the straw burning(24.5%)and domestic coal combustion(10.9%).The emission profile was featured by relatively higher percentages of naphthalene(30% of total emission)and six carcinogenic species(26% of the total emission).Spatial distribution showed that PAHs emissions were high in the areas with rapid economic development and dense population,e.g.area around Bohai,the Yangtze River Delta region,Sichuan-Chongqing region and northeast of China.In this study,the largest uncertainty was observed in industrial sources,with the uncertainty range of-204% to 1243%.The main reason is the uncertainty associated with emission factors.