On the Contribution of Biomass Burning to POPs (PAHs and PCDDs) in Air in Africa

0397204 - ÚVGZ 2014 RIV US eng J - Journal Article
Lammel, G. - Heil, A. - Stemmler, I. - Dvorská, Alice - Klánová, J.
On the Contribution of Biomass Burning to POPs (PAHs and PCDDs) in Air in Africa.
Environmental Science and Technology. Roč. 47, č. 20 (2013), s. 11616-11624. ISSN 0013-936X. E-ISSN 1520-5851
Institutional support: RVO:67179843
Keywords : Polyclic Aromatic-Hydrocarbons * Dibenzo-p-dioxins * persistent organic pollutants * Aerosol-climate model * Sout Atlantic transect * emission factors * heterogeneous reactivity * assimilation system * forest * fire
Subject RIV: DI - Air Pollution ; Quality
Impact factor: 5.481, year: 2013

Forest, savannah, and agricultural fires in the tropics and subtropics are sources for widespread pollution and release many organic substances into the air and soil, including persistent organic pollutants, i.e., polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs). The significance of this source for the exposure of humans and the environment in Africa toward phenanthrene, fluoranthene, pyrene, benzo(a)- pyrene, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, and octachlorodibenzo- p-dioxin is studied using daily global emissions from vegetation fires observed by satellite and a global multicompartment chemistry-transport model. Near-ground atmospheric concentrations of model-predicted vegetation fire related concentrations of PAHs and PCDDs were in the 10−1000 and 10−5−10−3 pg m−3 ranges, respectively. Vegetation fires in Africa are found to emit 180 ± 25 kg yr−1 of PCDD/Fs. By comparison with observations, it is found that fires explain 1−10% of the PCDD (5% of 2,3,7,8- tetrachlorodibenzo-p-dioxin) concentrations in the rural and background atmosphere of sub-Saharan Africa. The contribution of vegetation fires to exposure to PAH is probably >10%, but cannot be quantified due to lack of knowledge with regard to both emission factors and photochemistry. A sensitivity analysis suggests that the heterogeneous reaction of PAHs with ozone is effectively limiting atmospheric lifetime and long-range transport.
Permanent Link: http://hdl.handle.net/11104/0224860