Wildland Fire Smoke Health Effects on Wildland Firefighters and the Public

Project Description

The overall aim of this study was to compare the results of the smoke exposure meta-analysis proposed in to the results of proposed smoke toxicology studies to determine the similarities and differences between exposures and endpoints of well-defined smoke aerosols in the absence of ambient particulate matter (PM).

Purpose and Scope

Wildland fire smoke is a complex mixture of air contaminants that have the potential cause adverse health effects. In this study, we proposed to (a) determine the degree to which inhalation of fine and ultrafine wood smoke aerosols affect cardiovascular health and function using a genetically modified animal model; (b) determine if aging of smoke significantly alters the inherent toxicity of the aerosol; (c) determine if the effects of smoke exposure are transient or if they are progressive; and (d) summarize the literature documenting the association between community and work-related exposures to wildland fire smoke and population level health effects.

Methods

First, we conducted a literature review to identify smoke components that present the highest health hazard potential, the mechanisms of their toxicity, and reviewed epidemiological studies to identify the current gaps in knowledge about the health impacts of wildland fire smoke exposure for firefighters and the public.

Next, we examined wildland firefighter exposures, explored predictors of smoke exposures to determine factors influencing smoke exposure for wildland firefighters, and estimated exposure to air pollutants using carbon monoxide (CO) as an indicator pollutant.

Lastly, we estimated disease risk in wildland firefighters for exposure to particulate matter from smoke using firefighter specific breathing rates with existing exposure response relationship information for risk of lung cancer, ischemic heart disease and cardiovascular disease from cigarette smoking, which produces particulate matter with a similar size range.

Key Findings

From the literature review, we found that respiratory events measured in time series studies as incidences of disease-caused mortality, hospital admissions, emergency room visits and symptoms in asthma and chronic obstructive pulmonary disease patients are the health effects that are most commonly associated with public exposure to wildland fire smoke. The data presented clearly identified the crews and activities most likely to exceed occupational exposure limits.  A conclusion of this research is that there remains a need for research on acute and longer-term effects of wildland fire smoke exposure. The health effects of acute exposures beyond susceptible populations, and the effects of chronic exposures experienced by the wildland firefighter, are largely unknown.

Project Deliverables

• Two referred publications, one on a study of the toxicity of wildland fire smoke, and the other a meta-analysis of hospital emissions during wildfires.
• Presentation of data at a national conference.
• Risk assessment model linked to JFSP 13-1-02-14.
• Final report summary (see Resources)
• Final report to the Joint Fire Science Program (see Resources)