It comes as no surprise that our contamination-control efforts focus on mitigating exposures and the aftereffects of structural fires. These events represent the densest contamination exposure for firefighters.
Consequently, much of the information directed to firefighters covers the range of topics addressing PPE effectiveness, post-incident decontamination and cleaning. Yet other emergency response events warrant similar attention for lessening firefighter exposure to hazardous chemicals and other substances. Specifically, with the ever-increasing surge of wildland firefighting and the related rise of wildland/urban interface firefighting, there is an equal need to address the same hazards and controls for wildland firefighting.
Wildland firefighting gear and limitations
Wildland firefighting is best characterized as extended “in the field” fire suppression activities, typically undertaken in woodlands, forests, grasslands and other areas of vegetation outside populated areas. However, wildland fires isolated to wilderness are becoming rarer as urban and suburban development extends into once-desolate areas.
The fuel loads for wildland fires can be significantly different than the complex synthetic material-based structural fires of populated areas. But this situation is also changing as homeowners add more modern furnishings to homes located outside populated areas.
One factor that is quite different between structural firefighting and wildland firefighting is the gear. Wildland fire gear is designed for long-term wear and is often worn during suppression activities meant to prevent future fire spread through the creation of firebreaks, more so than direct mitigation activities.
Historically, wildland firefighters have worn single-layer, uniform-like flame-resistant clothing that is sometimes of a heavier weight to meet NFPA 1977 thermal insulation requirements while providing balanced comfort through minimum levels of total heat loss. Some clothing looks like turnout clothing but just doesn’t include the liner.
Increasingly, manufacturers are offering more efficient fabrics that provide good tradeoffs between heat protection and comfort. But there has also been a trend toward multilayer clothing or combining NFPA 1977 clothing with suitable, no melt/no drip base-layer clothing. Thus, wildland firefighting protective clothing is typically much simpler in design with many fewer layers than structural clothing. Nearly all of the wildland gear lacks any type of moisture barrier, as such a layer would be intolerable for the duration of most wildland firefighting activities and environmental conditions. Moreover, most fabrics used in wildland gear are not finished the same way as their counterparts for turnout clothing, meaning that contamination can potentially accumulate and penetrate these wildland protective clothing materials more readily. Therefore, wildland firefighters are more likely to be exposed to airborne particulate contaminants and fire gases.
The rest of the wildland firefighting ensemble also differs from the ensemble used for structural firefighting. Most notably absent is any form of respiratory protective equipment, as much of wildland firefighting can take place away from smoke plumes. Many wildland firefighters still use bandanas and makeshift masks in areas where smoke exposure may occur.
Gloves are leather work gloves, durable leather footwear is prevalent, and lighter weight helmets that offer some flame and heat resistance round out the ensemble. These items may be supplemented with a shroud or a hood, often more dependent on weather conditions. Wildland fire shelters are carried as a means of last resort for emergency fire conditions when overwhelmed by a rapidly spreading wildfire.
Wildland fire exposure and contamination
All wildland firefighting clothing items are subject to contamination, though at much lower levels than what may occur during an interior structural entry. Nevertheless, wildland fire exposures can occur over much longer durations where firefighters operate close to fire areas, and may become more extreme as fire approach urban areas where different tactics are employed. This means that clothing can accumulate contamination over its extended use, resulting in longer-term exposures.
Because of these concerns, researchers have been studying wildland fire exposures more carefully in recent years. Work undertaken by the U.S. Forest Service from the U.S. Department of Agriculture has already established an increased risk of wildland firefighter risk for lung cancer and cardiovascular disease mortality.1 It has also been found that wildland firefighters engaged in maintaining fire within designated firelines and performing direct attack of spot fires that cross firelines are more apt to be exposed to higher concentrations of fire gases and other contaminants.2
Other researchers have found elevated levels of polycyclic aromatic hydrocarbons (PAHs) associated with wildland firefighters during job tasks that involve the most direct contact with smoke near an actively burning wildland fire.3 When urban/interface areas are introduced, these exposures levels become even more elevated. Use of a biomarker for adsorbed PAH levels within the urine of wildland firefighters engaged in suppression activities in heavy wildland firefighters showed measureable levels that was generally mitigated by good hygiene practices.4 These findings suggest that wildland firefighters have exposure to contaminants through both inhalation and skin absorption. Consequently, clothing contamination is a likely potential source of continuing contamination.
Cleaning wildland gear
While there has been an emphasis on cleaning structural firefighting clothing following structural fires, the same is not true for wildland firefighting. This can be problematic in several respects:
- Wildland firefighters may wear the same clothing repeated over days of their fireline activity, making it possible for longer term exposure to contaminated clothing.
- Wildland firefighters often have limited resources to isolate contaminated clothing from other clothing and equipment.
- Wildland firefighters may not have the same access to cleaning facilities as other firefighters.
- Very little specific research has been performed to evaluate cleaning effectiveness for wildland firefighting clothing.
Recent work undertaken as part of U.S. Department of Homeland Security Assistance to Firefighter Grant Program study found that traditional measurements for assessing wildland firefighter exposure risk were likely underreporting contaminant levels on both firefighter skin and clothing.5 This study showed that contamination is present but sometimes can be difficult to detect using the usual techniques for collection, extraction and analysis.
In a limited survey conducted as part of this study, the following responses were received from 391 firefighter participants:
- Firefighters tended to rate their confidence in current decontamination protocols as less than average and were generally concerned about skin exposures during wildland fires.
- 44% of firefighters cleaned or replaced their clothing about once a week.
- Firefighters attempted to mostly wash their hands at the end of a shift, but mainly never during an incident.
- 5% regularly used skin wipes.
- 78% of wildland firefighters did not follow any rigorous decontamination protocol following a wildland fire.
- 19% of wildland firefighters isolated their PPE during an extended deployment on an incident.
Certainly, more work is needed to provide awareness on the need for cleaning, demonstrate that cleaning can be undertaken, and to find pragmatic approaches for how the cleaning of gear can be carried out.
Further research and a new standard
The NFPA has been working on a new standard – NFPA 1877 – related to the selection, care and maintenance for wildland firefighting protective clothing and equipment that will issue later this year.
Further work is occurring in parallel to continue the investigation of methods that enable wildland firefighters to more easily clean their gear. One such effort is a comprehensive survey that will allow researchers from multiple organizations to gather more information about current cleaning practices so that best practices can be created to support cleaning of wildland gear.
The survey is part of a study being conducted by Dr. Meredith McQuerry at Florida State University. The purpose of this study is to obtain data on the end user’s wildland firefighting experience and PPE cleaning practices.
1. Navarro, K. M., Kleinman, M. T., Mackay, C. E., Reinhardt, T. E., Balmes, J. R., Broyles, G. A., & Domitrovich, J. W. (2019). Wildland firefighter smoke exposure and risk of lung cancer and cardiovascular disease mortality. Environmental research, 173, 462-468.
2. Reinhardt, T. E., & Ottmar, R. D. (2004). Baseline measurements of smoke exposure among wildland firefighters. Journal of occupational and environmental hygiene, 1(9), 593-606.
3. Navarro, K. M., Cisneros, R., Noth, E. M., Balmes, J. R., & Hammond, S. K. (2017). Occupational exposure to polycyclic aromatic hydrocarbon of wildland firefighters at prescribed and wildland fires. Environmental science & technology, 51(11), 6461-6469.
4. Cherry, N., Aklilu, Y. A., Beach, J., Britz-McKibbin, P., Elbourne, R., Galarneau, J. M., & Zhang, X. (2019). Urinary 1-hydroxypyrene and skin contamination in firefighters deployed to the Fort McMurray fire. Annals of work exposures and health, 63(4), 448-458.
5. Rahn, M., Stricker, K., Rodriguez, A., Swan, R., Brown, C., & Edwards, T. (2020). Occupational exposures and firefighter risk in wildland and urban interface fires: Dermal and personal protective equipment contamination. Assistance of Firefighters Grant Program, Fire Prevention and Safety Grants, Project EMW-2013-FP-00621, California State University San Marcos.
Note: The views of the author do not necessarily reflect those of the sponsor.