Wildfire smoke and public health risk

Abstract

Wildfire activity is predicted to increase with global climate change, resulting in longer fire seasons and larger areas burned. The emissions from fires are highly variable owing to differences in fuel, burning conditions and other external environmental factors. The smoke that is generated can impact human populations spread over vast geographical areas. Wildfire smoke is a complex mixture of pollutants that can undergo physical and chemical transformation processes during transport and can have major impacts on air quality and public health. This review looks at the main features of smoke that should be considered in the assessment of public health risk. It describes the current state of knowledge and discusses how smoke is produced, what factors affect emissions and smoke distribution, and what constituents of smoke are most likely to cause adverse health effects.

Air quality policy and fire management responses addressing smoke from wildland fires in the United States and Australia

“…For example, although wildland fires can be linked to ozone exceedances, the attribution of ozone exceedances to this source is challenging. Smoke plumes can block sunlight, delaying ozone formation (Jaffe and Wigder 2012); the precursor gases for ozone production, particularly volatile organic compounds, can have other large environmental sources (Simpson et al 2011); and emitted NO x can be transformed into peroxyacetyl nitrate (PAN), delaying ozone formation until PAN decomposes back to NO x downwind (Komarek 1971;Reisen et al 2015).…”

“…However, all wildland fires produce a suite of atmospheric pollutants (e.g. particulate matter, carbonaceous and nitrogenous species, and ozone precursors) (Komarek 1971;Reisen et al 2015) that affect atmospheric chemistry and air quality at local, regional and global scales (Damoah et al 2004;Sodemann et al 2011;US EPA 2012). Unlike emissions from industry and transportation, wildland fire emissions are spatially and temporally episodic and they can impair visibility and have negative short-and long-term impacts on public health (Crutzen and Andreae 1990;Bowman et al 2009;Liu et al 2015;Adetona et al 2016).…”

“…Specifically, these include a deepening awareness of the health impacts of wildland fire emissions (e.g. Morgan et al 2010;Caamano-Isorna et al 2011;Dennekamp and Abramson 2011;Reisen et al 2015) trends towards increasing population density in the wildland-urban interface (Theobald and Romme 2007;Mell et al 2010), increases in amenity-based migration towards wildlands by older and thus more air pollution-sensitive populations (Shumway and Otterstrom 2001), and a projected increase in the frequency of large and high-intensity wildfires due to climate change (Westerling et al 2006;Pechony and Shindell 2010;IPCC 2013). Equally, as global change causes shifts in historical fire patterns, frequencies and magnitudes of their impacts, other countries will likely seek to develop complementary policies.…”

Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling

“…In Australia, BB from wild and prescribed fires impacts air quality in both rural and urban areas (Keywood et al, , 2011aReisen et al, 2011;Luhar et al, 2008) as well as indoor air quality (Reisen et al, 2011). More generally, as human population density increases, and as wildfires become more frequent (Flannigan et al, 2009;Keywood et al, 2011b), assessing the impact of BB on air quality and human health becomes more urgent (Keywood et al, 2011b;Reisen et al, 2015). In particular, particles emitted from BB frequently lead to exceedances of air quality standards, and exposure to BB particles has been linked to poor health outcomes including respiratory effects, cardiovascular disease and mortality (Reisen et al, 2015;Reid et al, 2016;Dennekamp et al, 2015).…”

“…More generally, as human population density increases, and as wildfires become more frequent (Flannigan et al, 2009;Keywood et al, 2011b), assessing the impact of BB on air quality and human health becomes more urgent (Keywood et al, 2011b;Reisen et al, 2015). In particular, particles emitted from BB frequently lead to exceedances of air quality standards, and exposure to BB particles has been linked to poor health outcomes including respiratory effects, cardiovascular disease and mortality (Reisen et al, 2015;Reid et al, 2016;Dennekamp et al, 2015). There is also increasing evidence that mixing of BB emissions with urban emissions results in enhanced photochemistry and production of secondary pollutants such as secondary aerosol and O 3 (Jaffe and Wigder, 2012;Akagi et al, 2013;Hecobian et al, 2012), which may result in more significant health impacts than exposure to unmixed BB or urban emissions.…”