Chemistry Reference
In-Depth Information
suggested to be due to the chemical transformation of the organic fraction during
the transport [
48
]. However, due to the increased PM concentration in the accumu-
lation mode, the smoke episodes can be assumed to be associated with enhanced
toxic potential per inhaled cubic meter of air, which may have public health
implications. Biomass burning smoke consists of a mixture of different chemical
components. In case of Californian wildfires in 2008, PM in coarse size fraction was
found to be highly toxic to lung cells (macrophages), the active components being
heat-labile organic compounds [
49
]. In general, there is no reason to assume that the
biomass burning-related particles are less dangerous than particles from other
sources [
46
].
7 Conclusions
LRT pollution from the wildfires has been observed in the northern European
regions almost every year and recognized as one significant source of atmospheric
pollution. As the PM concentrations are typically quite low in Northern Europe, the
LRT smoke plumes increase the PM concentrations in several folds even at
background sites with no local emissions. During the LRT smoke episodes daily
average PM
2.5
concentrations typically reach 30-50
gm
3
, which is approxi-
mately three- to sixfold compared with the annual mean PM
2.5
concentration and
can result in exceedance in the European Union PM
10
daily limits. The chemical
composition of smoke particles differs from that of particles usually measured at the
site. That probably has an effect on the toxicity of PM, however, the overall
harmfulness of breathing smoky air is probably caused by much increased PM
mass in a cubic meter of inhaled air. The most visible effect of the arrival of smoke
plume is the smell of especially fresh smoke and decreased visibility but LRT
smoke also causes acute health effects, morbidity, and premature deaths in the
northern European countries.
Hot and dry meteorological conditions in summer increase the extent of
observed biomass fires. For example, the summer of 2010 was exceptionally
warm in Eastern Europe and large parts of Russia. With climate change such
extreme events are predicted to increase and by the end of the century heat waves
of this magnitude are expected to occur every decade [
50
]. For European Arctic the
transport of smokes from more frequent biomass fires may affect the global climate
change. Whether the Arctic is getting warmer or colder because of the smoke events
is still under evaluation.
Wildfires have the most significant impact on people in the region close to the
fires, but as being a transboundary pollutant, smoke also causes troubles thousands
of kilometers away from the burning. In order to avoid air quality deterioration both
in the areas near the fires as well as in distant countries, people need to be enforced
to change the current agricultural burning practices as well as extinguish existing
fires more efficiently.
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