Global Atmospheric Emissions of Polycyclic Aromatic Hydrocarbons from 1960 to 2008 and Future Predictions

Abstract

Global atmospheric emissions of 16 polycyclic aromatic hydrocarbons (PAHs) from 69 major sources were estimated for a period from 1960 to 2030. Regression models and a technology split method were used to estimate country and time specific emission factors, resulting in a new estimate of PAH emission factor variation among different countries and over time. PAH emissions in 2007 were spatially resolved to 0.1°× 0.1° grids based on a newly developed global high-resolution fuel combustion inventory (PKU-FUEL-2007). The global total annual atmospheric emission of 16 PAHs in 2007 was 504 Gg (331-818 Gg, as interquartile range), with residential/commercial biomass burning (60.5%), open-field biomass burning (agricultural waste burning, deforestation, and wildfire, 13.6%), and petroleum consumption by on-road motor vehicles (12.8%) as the major sources. South (87 Gg), East (111 Gg), and Southeast Asia (52 Gg) were the regions with the highest PAH emission densities, contributing half of the global total PAH emissions. Among the global total PAH emissions, 6.19% of the emissions were in the form of high molecular weight carcinogenic compounds and the percentage of the carcinogenic PAHs was higher in developing countries (6.22%) than in developed countries (5.73%), due to the differences in energy structures and the disparities of technology. The potential health impact of the PAH emissions was greatest in the parts of the world with high anthropogenic PAH emissions, because of the overlap of the high emissions and high population densities. Global total PAH emissions peaked at 592 Gg in 1995 and declined gradually to 499 Gg in 2008. Total PAH emissions from developed countries peaked at 122 Gg in the early 1970s and decreased to 38 Gg in 2008. Simulation of PAH emissions from 2009 to 2030 revealed that PAH emissions in developed and developing countries would decrease by 46-71% and 48-64%, respectively, based on the six IPCC SRES scenarios.

Urban and rural transport of semivolatile organic compounds at regional scale: A multimedia model approach

“…In addition, the relative errors (RE) between measured and simulated concentrations in most compartments became smaller (Table S2), which could be mainly attributed to the separate treatment of urban and rural areas in each compartment. Another reason may be that the estimated emissions adopted from the data by Shen et al (2013) shown in Fig. 5 were nearly 2 times larger than Liu's estimated BaP emissions in the study area.…”

“…In the BETR-UR model, emissions should be estimated separately in the urban and rural areas. This paper will not focus on the discussion of chemical emission estimates, which are available from another publication (Shen et al, 2013). In addition, the parameters of advection rates (m 3 /sec) and diffusion MTC (m/sec) will affect the exchange ratios between rural and urban air.…”

“…The global atmospheric emissions of 16 PAHs at the country level for a period from 1960 to 2030 from 69 major sources were estimated by Shen et al (2013), which were mainly from six sectors (energy production, industry, transportation, commercial building, agriculture, and natural sources). Regression models and a technology split method were used to estimate country-and time-specific emission factors (Shen et al, 2013 (Table S2).…”

“…Regression models and a technology split method were used to estimate country-and time-specific emission factors (Shen et al, 2013 (Table S2). Available measured data for PAH concentrations in the year of 2008 were collected from published sources (Jiao, 2009;Liu et al, 2010;Men et al, 2009;Peng et al, 2011;Shi et al, 2010;Wang et al, 2011;Zheng et al, 2010; Liu et Fig.…”

“…The BETR modeled result was the spatial average concentration in one sub-region, which may represent the average concentrations in various land use types such as urban land and farm land. Actually, the emissions of PAHs were considerably different between urban and rural areas (Shen et al, 2013). The BETR model application in the Chinese Bohai coastal region showed that the modeled concentrations of Benzo [α]pyrene (BaP) in air, fresh water, soil, and sediment generally agreed with field observations except for the soil concentration of urban areas, and the measured concentration of soil obtained from Beijing, one of the most developed cities in China, was 7 times higher than the modeled value (Liu et al, 2014).…”