Assessing relative differences in smoke exposure from prescribed, managed, and full suppression wildland fire

A novel approach is presented to analyze smoke exposure and provide a metric to quantify health-related impacts. Our results support the current understanding that managing low-intensity fire for ecological benefit reduces exposure when compared to a high-intensity full suppression fire in the Sierra Nevada of California. More frequent use of fire provides an opportunity to mitigate smoke exposure for both individual events and future emission scenarios. The differences in relative exposure between high-intensity, low-intensity, and prescribed burn were significant (P value < 0.01). Suppressing fire not only appears to shift the health burden of the emissions to a future date but also increases the intensity and number of people exposed in a single exposure. Increased use of ecologically beneficial fire may further be optimized to reduce human exposure through advantageous use of good dispersal conditions and incorporating a mitigation strategy that includes poor dispersal when smoke is largely over wilderness or other natural areas. Accepting naturally occurring fire typical of the environmental system benefits forest health and reduces public exposure to smoke.