The Wildland Firefighter Exposure and Health Effect (WFFEHE) Study: Rationale, Design, and Methods of a Repeated-Measures Study

Abstract

The wildland firefighter exposure and health effect (WFFEHE) study was a 2-year repeated-measures study to investigate occupational exposures and acute and subacute health effects among wildland firefighters. This manuscript describes the study rationale, design, methods, limitations, challenges, and lessons learned. The WFFEHE cohort included fire personnel ages 18–57 from six federal wildland firefighting crews in Colorado and Idaho during the 2018 and 2019 fire seasons. All wildland firefighters employed by the recruited crews were invited to participate in the study at preseason and postseason study intervals. In 2019, one of the crews also participated in a 3-day midseason study interval where workplace exposures and pre/postshift measurements were collected while at a wildland fire incident. Study components assessed cardiovascular health, pulmonary function and inflammation, kidney function, workplace exposures, and noise-induced hearing loss. Measurements included self-reported risk factors and symptoms collected through questionnaires; serum and urine biomarkers of exposure, effect, and inflammation; pulmonary function; platelet function and arterial stiffness; and audiometric testing. Throughout the study, 154 wildland firefighters participated in at least one study interval, while 144 participated in two or more study interval. This study was completed by the Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health through a collaborative effort with the U.S. Department of Agriculture Forest Service, Department of the Interior National Park Service, and Skidmore College. Conducting research in the wildfire environment came with many challenges including collecting study data with study participants with changing work schedules and conducting study protocols safely and operating laboratory equipment in remote field locations. Forthcoming WFFEHE study results will contribute to the scientific evidence regarding occupational risk factors and exposures that can impact wildland firefighter health over a season and across two wildland fire seasons. This research is anticipated to lead to the development of preventive measures and policies aimed at reducing risk for wildland firefighters and aid in identifying future research needs for the wildland fire community.

Respiratory Tract and Eye Symptoms in Wildland Firefighters in Two Canadian Provinces: Impact of Discretionary Use of an N95 Mask during Successive Rotations

“…The wealth of data would be invaluable in assessing the relation of firefighting activities to chronic respiratory ill-health. Recent studies have reported differences in exposures between firefighting tasks [ 14 , 15 ]. Here, the analysis of discretionary mask use may give some indication of perceived smoke intensities, with mask use being greatest during initial attack and least while driving and patrolling.…”

“…Such a study is still needed and would ideally have a full factorial design with random allocation of crews to interventions. Given the vagaries of ‘real life’ fieldwork [ 15 ] with, as here, COVID-19 restrictions together with calamitous fires in one province and few fires in the other, this would need major investment and organization. The conclusions from this study, with its several limitations, support the need for more effective intervention to reduce respiratory exposure, particularly for tasks carried out by unit crews.…”

Nicotine suppresses crystalline silica‐induced astrocyte activation and neuronal death by inhibiting NF‐κB in the mouse hippocampus

“…Chronic CS exposure has been shown to cause inflammation of the central nervous system (CNS), leading to depression and a decline in cognitive abilities 6,7 . There is a growing understanding that occupational exposure to dust can impact brain function in various ways, with effects on oxidative stress, the inflammatory response, and neurotransmitters 8 . Prior research has demonstrated the significance of hippocampal regions in regulating mood and cognitive functioning.…”

Subclinical Measures of Cardiovascular Health Among Wildland Firefighters

“…6,7 The common workplace hazard of WFFs include smoke, arduous duty, high physical stress, sleep disturbance and deprivation, shift work, heat exposure, and dehydration. [8][9][10][11] Approximately 19,000 federal WFFs worked under the Department of Agriculture's Forest service and four agencies of Department of Interior (DOI). 12 Wildland firefighting is a physically demanding, and young and healthy individuals tend to self-select into this arduous duty occupation.…”

“…This increase in fire affects the people living in communities near where wildfires occur and wildland firefighters (WFFs) who are directly or indirectly involved in suppressing wildland fires 6,7 . The common workplace hazard of WFFs include smoke, arduous duty, high physical stress, sleep disturbance and deprivation, shift work, heat exposure, and dehydration 8–11 . Approximately 19,000 federal WFFs worked under the Department of Agriculture’s Forest service and four agencies of Department of Interior (DOI) 12…”