Inhalation Toxicology

Understanding the unique nature of wildfire smoke exposures and the resulting adverse health effects

With the increase in wildfires globally, the concern for understanding the potential health consequences of wildfire smoke is of great interest. Current guidance on mitigating the adverse effects from these exposures has focused on PM_2.5 levels as determined by historic urban air pollution studies. However, wildfire smoke exposures do not fit neatly into the urban air pollution paradigm. In addition to wildfire smoke events being generally of a short duration and highly concentrated, there is also the added consideration of multiple events within and across years. These exposures cannot be easily categorized as single, individual or chronic exposures, and there is a potential of either cumulative effects or synergistic effects of subsequent exposures.

While the contributions of wildfire smoke exposures to adverse health outcomes is appreciated from studies assessing increased hospital, emergency department, clinic visits, as well as increases in seasonal respiratory infections, the longitudinal effects and the mechanisms are not understood. The mitigating factors hampering the field include variations in smoke composition (fuels, flaming/smoldering, age) and the nature of the exposures themselves where, in addition to single high-dose events, there is the potential for multiple exposures within and across the years. In addition, translating studies into the laboratory setting is complicated by the lack of a normalized particle (i.e. SRM 1640) or system (exposure by concentration or deposition; instillation vs inhalation).

This special issue seeks contributions that will discuss the advantages and disadvantages of the various laboratory models (including in vitro vs in vivo), as well as the concept of defining the smoke exposures and considerations for addressing the contributions of multiple exposures, or that address other factors currently hampering the field’s understanding of health effects. Our goal is that the publications in this special issue will generate informative discussions on the burgeoning field of wildfire smoke research and the potential health effects from these exposures.  Submissions will be published online as they are accepted with a final complete issue published when all manuscripts are accepted.