Estimating the Air Quality Impacts of Fire

State-of-the-science methods used to determine the impact of fire on air quality and visibility include: (1) emission inventories; (2) air quality monitoring instruments to measure smoke concentrations in real-time; and (3) source apportionment, or filter-based monitoring techniques and receptor-oriented methods that quantify wildfire smoke contribution to air pollution based on the chemical characteristics of smoke particles or the spatial and/or temporal variability. Fire also contributes to ground-level ozone. These topics have become increasingly important to both air quality regulators and land managers as efforts to identify, or apportion, the contributions that fire makes to particulate air pollution, regional haze, and ground-level ozone come under increased scrutiny.

Because the health effects of air pollution are so difficult to measure in the broad population, there has been little effort to regulate or manage those effects directly. Many smoke management decisions are made on the basis of nuisance complaints as an indicator, rather than on quantitative measurements of impacts to health and welfare. Close to the source, efforts are being made to keep the exposure of firefighters to hazardous air pollutants within the standards set by the Occupational Safety and Health Administration. Hazard assessment describes the nature, concentration, and duration of pollutants. Exposure assessment quantifies the population exposed and the degree of exposure. Risk assessment describes the probable result for a population from all exposures. Integrated health risk assessments and economic assessments are still rare.

Modeling and data systems are needed to predict, measure, and monitor the ultimate effects of air pollution from fires on human or ecosystem health, on the economy, and on the comfortable enjoyment of life and property. Risk assessment methods are needed to compare these effects with those from other sources.