China National Emission [xls]
China Provincal Emission [xls]
China County Emission [xls]
China 1kmx1km Emission [Arcraster]

The emission factors for indoor straw combustion are a major data gap for estimating the polycyclic aromatic hydrocarbon (PAH) emissions in China. The emission factors for open-fire straw burning were borrowed from our previous study and a rough estimate has been developed. As one of the most important emission sources in China, Q1 the emission factors for indoor straw combustion needed to be determined and revised accurately. In this study, a representative straw in rural China was collected and burned in similar conditions with those used by countryside families. The smoke producedwas sampled and the PAH concentrations were analyzed by gas chromatography–mass selective detection (GC-MSD), andmuch higher emission factorswere found. Based on the newlymeasured emission factors, the emission amount from indoor straw combustion was updated. In addition, recently published emission factors were compiled in a comprehensive database and some new sources were included. Additionally, the emission inventory was extended to cover the period from 1950 to 2005 and upgraded to a scale resolution of one kilometer. In the updated inventory, the total quantity of 16 PAHs emitted from Chinawas 116,000 tons in 2003, with indoor strawand firewood combustions as themost important sources. Although vehicular emission contributed a relatively small percentage of the total emission, it was still one of the major sources in the urban areas of China. The total PAHemission increased continuously for four decades, starting from 1950, but fluctuated since 1990 due to variations in coke production.

Global Emission [xls]
Global 1degx1deg Emission [rar]

The global atmospheric emissions of the 16 polycyclic aromatic hydrocarbons (PAHs) listed as the US EPA priority pollutants were estimated using reported emission activity and emission factor data for the reference year 2004. A database for emission factors was compiled, and their geometric means and frequency distributions applied for emission calculation and uncertainty analysis, respectively. The results for 37 countries were compared with other PAH emission inventories. It was estimated that the total global atmospheric emission of these 16 PAHs in 2004 was 520 giga grams per year (Gg/y) with biofuel (56.7%), wildfire (17.0%) and consumer product usage (6.9%) as the major sources, and China (114 Gg/y), India (90 Gg/y) and United States (32 Gg/y) were the top three countries with the highest PAH emissions. The PAH sources in the individual countries varied remarkably. For example, biofuel burning was the dominant PAH source in India, wildfire emissions were the dominant PAH source in Brazil, while consumer products were the major PAH emission source in the United States. In China, in addition to biomass combustion, coke ovens were a significant source of PAHs. Globally, benzo(a)pyrene accounted for 0.05% to 2.08% of the total PAH emission, with developing countries accounting for the higher percentages. The PAH emission density varied dramatically from 0.0013 kg km2/y in the Falkland Islands to 360 kg km2/y in Singapore with a global mean value of 3.98 kg km2/y. The atmospheric emission of PAHs was positively correlated to the country’s gross domestic product and negatively correlated with average income. Finally, a linear bivariate regression model was developed to explain the global PAH emission data.