posted on 2024-03-14, 13:34authored byLaura Kiely, Soroush E. Neyestani, Samiha Binte-Shahid, Robert A. York, William C. Porter, Kelley C. Barsanti
Wildfires are a significant
threat to human health, in part through
degraded air quality. Prescribed burning can reduce wildfire severity
but can also lead to an increase in air pollution. The complexities
of fires and atmospheric processes lead to uncertainties when predicting
the air quality impacts of fire and make it difficult to fully assess
the costs and benefits of an expansion of prescribed fire. By modeling
differences in emissions, surface conditions, and meteorology between
wildfire and prescribed burns, we present a novel comparison of the
air quality impacts of these fire types under specific scenarios.
One wildfire and two prescribed burn scenarios were considered, with
one prescribed burn scenario optimized for potential smoke exposure.
We found that PM2.5 emissions were reduced by 52%, from
0.27 to 0.14 Tg, when fires burned under prescribed burn conditions,
considerably reducing PM2.5 concentrations. Excess short-term
mortality from PM2.5 exposure was 40 deaths for fires under
wildfire conditions and 39 and 15 deaths for fires under the default
and optimized prescribed burn scenarios, respectively. Our findings
suggest prescribed burns, particularly when planned during conditions
that minimize smoke exposure, could be a net benefit for the impacts
of wildfires on air quality and health.