Embedded Files
Ella Hommeyer (she/her)
MPH Candidate - OHSU-PSU School of Public Health
Environmental Systems and Human Health
Photo by Maria Thi Mai, Bureau of Land Management Oregon and Washington
How does fighting wildfires affect our ecosystems and health?
How does fighting wildfires affect our ecosystems and health?
While wildfires themselves can have devastating effects on the natural environment and people that live near them, some firefighting methods can cause ecological and human health harm. What harms should we be aware of and are there ways to mitigate them?
How We Fight Wildfires
How We Fight Wildfires
Image by Renee Lafountain, used with permission
Direct Attack
Direct Attack
Direct attacks, when safe to do so, are the standard initial response to wildfires. Often done when flames are relatively small (less than 4 feet long), these methods are used to cool, drown, smother, and starve an active wildfire.
Indirect Attack
Indirect Attack
The indirect attack is used when direct attack methods are not possible or practical, such as due to difficult terrain. Firefighters find a location ahead of the fire to establish control. This method allows firefighters to contain large fires that are unsafe to attack directly.
Direct Attack Methods
Direct Attack Methods
Hand Tools
Hand Tools
Wildland firefighters use an array of hand tools like shovels, rakes, or Pulaksis to smother the fire with dirt or drag burning debris back into the burn area.
Hand tools can also be used to create firebreaks by hand (often called handlines) as an indirect attack when the terrain restricts the movement of heavy machinery.
Hoses and Pumps
Hoses and Pumps
Hoses attached to a tankard or a backpack pump can be used to spray plain water, water enhanced with chemicals, or foam fire-retardants directly onto the ground. These are often used in tandem with hand tools or as part of a mobile attack.
Photo by BLM Idaho
Mobile Attacks
Mobile Attacks
Also known as pump and roll or running attacks, this technique involves a firefighter running or walking ahead of or next to a vehicle and directing the hose spray on the fire. When terrain allows, such as in valley floor and grasslands, using vehicles in tandem with firefighters on the ground can be effective to quickly and efficiently put out fires.
Indirect Attack Methods
Indirect Attack Methods
Aerial Attacks
Aerial Attacks
Aerial firefighting involves planes and helicopters dropping water or long-term fire retardants around the perimeter of a wildfire to contain the spread. Helicopters often pick up water by the bucketful from local sources like lakes, large rivers and even swimming pools.
Photo by Master Sgt. Jeremy Lock, U.S. Air Force
Firebreaks and Trenching
Firebreaks and Trenching
Firebreaks, also referred to as firelines, are gaps in combustible material used to stop or slow down the spread of wildfires. These lines can be made by hand or heavy machinery and involves clearing away vegetation that could be fuel for fire and stripping the land down to mineral soil. They are most often created by bulldozers when the terrain allows.
Natural or existing firebreaks may also be used to complete the control line. These include things like bluffs, bodies of water, and roads.
Trenching is a method where a small ditch is dug below a fire on sloping ground to catch rolling material and prevent the fire from breaking through the fireline.
Burnout and Backfire
Burnout and Backfire
Burning out and backfiring are ways of literally fighting fire with fire. Drip torches (a type of hand-held torch with gasoline and diesel fuel) are used to help establish control lines.
Burning out involves intentionally burning vegetation within the fireline in order to widen the control line and reduce the fuel available to the wildfire. This typically happens on a smaller scale than backfiring.
Backfiring is a complex procedure that involves burning large areas of fuel within the fireline on the active fire edge, often to consume the fuel in front of the wildfire.
Photo by Ted Erski
Public Health Implications of Fire Suppression Methods
Public Health Implications of Fire Suppression Methods
Occupational Hazards
Occupational Hazards
Direct attacks put firefighters very close to fires, exposing them to extreme heat and smoke inhalation which can damage the lungs, kidneys, heart, and other vital organs.
Ingredients in fire-retardants are known carcinogens, putting firefighters and support personnel at increased risk of developing cancer (CDC, 2021).
Working on wildfires is a high-stress environment. Many wildland firefighters experience increased mental-health issues. Learn more about the mental health of wildland firefighters.
Ecological Hazards
Ecological Hazards
Long-term retardants used in aerial are made up primarily of fertilizer. Excess fertilizer can enter waterways via runoff and cause toxic algae blooms (Ardón et al., 2020).
Foam suppressants used in direct attacks contain polyfluoroalkyl substances (PFAS) which persist in the environment, seeping into soil and water sources and bioaccumulating in animals. PFAS have been linked to negative health effects in humans and animals (Department of Defense, n.d.). Learn more about fire-retardant chemicals.
Drip torch fuel used to burnout and backfire is 1 part gasoline to 3 parts diesel fuel. This often does not burn completely and leaves residual fuel on the ground. Residual fuel can leach into soil and enter waterways via runoff (ESCOGO, 2020). Ingesting diesel and gasoline can cause damage to the central nervous system, liver, and kidneys in humans.
Bulldozed firelines can increase soil erosion which leads to increased sediment and runoff into nearby water sources (Grangeon et al. 2021). Erosion can be particularly harmful since the chemicals used in fire suppression, both as fire-retardants and as fuel, can be detrimental to aquatic ecosystems.
Potential Solutions
Potential Solutions
Wildfire suppression measures can be harmful to our health and ecosystems. In order to reduce the impact of both wildfires and their containment methods, efforts should be made to mitigate the damage wildfires can cause before they start.
Photo by Everglades National ParkWildfire suppression measures can be harmful to our health and ecosystems. In order to reduce the impact of both wildfires and their containment methods, efforts should be made to mitigate the damage wildfires can cause before they start.
Image Citations
U.S. Fish and Wildlife Service, Mountain Prairie Region
David Hercher, U.S. Forest Service
Greg Shine, BLM Oregon and Washington
Related Topics
Related Topics
References
References
Ardón, M., Zeglin, L. H., Utz, R. M., Cooper, S. D., Dodds, W. K., Bixby, R. J., Burdett, A. S., Follstad Shah, J., Griffiths, N. A., Harms, T. K., Johnson, S. L., Jones, J. B., Kominoski, J. S., McDowell, W. H., Rosemond, A. D., Trentman, M. T., Van Horn, D., & Ward, A. (2020). Experimental nitrogen and phosphorus enrichment stimulates multiple trophic levels of algal and detrital based food webs: A global meta-analysis from streams and rivers. Biological Reviews, 96(2), 692–715. https://doi.org/10.1111/brv.12673
Bolton, N. (2011, September 1). Defending Against Fire, Guarding Against Erosion. Stormwater. Retrieved November 14, 2022, from https://www.stormh2o.com/erosion-control/vegetation-management/article/13006490/defending-against-fire-guarding-against-erosion
Centers for Disease Control and Prevention. (2021, January 8). Firefighter cancer awareness. Centers for Disease Control and Prevention. Retrieved December 9, 2022, from https://www.cdc.gov/niosh/newsroom/feature/firefighter-cancer-awareness.html#:~:text=Cancer%20is%20a%20leading%20cause,compared%20to%20the%20general%20population
Davies, K. W., Wollstein, K., Dragt, B., & O'Connor, C. (2022). Grazing management to reduce wildfire risk in invasive annual grass prone sagebrush communities. Rangelands, 44(3), 194–199. https://doi.org/10.1016/j.rala.2022.02.001
Department of Defense. (n.d.). Per- and Polyfluoroalkyl Substances. DENIX. Retrieved December 9, 2022, from https://denix.osd.mil/dod-pfas/
ESCOGO. (2020, October 14). EnviroBurn Drip Torch Fuel. ESCOGO. Retrieved December 9, 2022, from https://escogo.com/enviroburn-drip-torch-fuel/
Grangeon, T., Vandromme, R., Cerdan, O., De Girolamo, A. M., & Lo Porto, A. (2021). Modelling forest fire and firebreak scenarios in a Mediterranean mountainous catchment: Impacts on sediment loads. Journal of Environmental Management, 289. https://doi.org/10.1016/j.jenvman.2021.112497
State of Michigan. (2002). Introduction to Wildland Fire Suppression for Michigan Fire Departments. Retrieved November 14, 2022, from https://www.michigan.gov/lara/bureau-list/bfs
National Wildfire Coordinating Group. (n.d.). Module 9: Suppression, Communication, and Mop-up. Retrieved November 14, 2022, from https://training.nwcg.gov/classes/s130/508%20Files/071231_s130_m9_508.pdf
Wang, H.-H., Finney, M. A., Song, Z.-L., Wang, Z.-S., & Li, X.-C. (2021). Ecological techniques for wildfire mitigation: Two distinct fuelbreak approaches and their fusion. Forest Ecology and Management, 495, 119376. https://doi.org/10.1016/j.foreco.2021.119376
Weir, J. R., Bidwell, T. G., Stevens, R., & Mustain, J. (2017, March 1). Firebreaks for Prescribed Burning. Firebreaks for Prescribed Burning. Oklahoma State University. Retrieved November 14, 2022, from https://extension.okstate.edu/fact-sheets/firebreaks-for-prescribed-burning.html
Page updated
Google Sites
Report abuse