Emissions and Atmospheric Chemistry of Furanoids from Biomass Burning: Insights from Laboratory to Atmospheric Observations

Furanoids are a class of reactive volatile organic compounds
that
are major products from the pyrolysis and combustion of biomass polymers,
including cellulose, hemicellulose, and lignin. Biomass burning is
an atmospheric source of furanoids that is increasing in frequency
and intensity throughout regions of the world. Once emitted to the
atmosphere, furanoids may react with the major atmospheric oxidants
to form secondary pollutants that are hazardous to human health, including
ozone (O3) and secondary organic aerosol (SOA). This review
is a comprehensive assessment of the literature between 1977 and the
present describing the emissions and atmospheric fate of furanoids
emitted from wild, prescribed, and domestic fires. The review is organized
by presenting the physical properties of key furanoids first, followed
by a summary of the biopolymer pyrolysis and combustion reactions
that lead to furanoid formation. Next, furanoid emissions factors
are compiled across the typical fuels consumed by biomass burning
to highlight the key species emitted in smoke. We next review the
available kinetic and atmospheric degradation mechanism data that
characterize the reaction rates, gas-phase products, and SOA formed
as a result of furanoid reactions with OH, NO3, O3, and Cl radicals. We then describe studies that have focused on
evaluating furanoid atmospheric chemistry and their impacts on air
quality using a combination of field observations and model simulations.
We conclude with a perspective that identifies future research directions
that would address key data gaps and improve the understanding of
furanoid atmospheric processes.