Wildfires, Fire Retardants, and Wildlife

More frequent wildland fire events in California have resulted in jurisdictions spraying greater amounts of fire retardants to mitigate the potential devastation of this natural disaster.

Wildland fires are wildfires and often threaten wildland urban interfaces which spur anthropogenic interaction via suppression techniques. However, scientific research to study the effects of the routine use of fire retardants relative to biodiversity within the ecosystems post-application has not been carried out.

Examining fire ecology, fire suppression techniques, and fire suppression agents provides a better understanding into the areas of scientific research that needs to be undertaken. 

• Discuss alternative mitigation measures, such as range management, that minimally interfere with wildlife health.

• Discover the research that should be done to gain scientific data on the One Health impacts in California due to increased spraying of wildfire fire retardants.

• Determine further policy changes that can be made to promote safety in wildlife, humans, and the environment.

Long term fire retardants are being applied in larger quantities across the state of California due to more high intensity fires endangering human life and safety. These retardants are designed to target specific areas to create firebreaks and the opportunity for firefighters to manipulate the flames. However, with a change from low intensity fires to more frequent high intensity fires, they are now sprayed as blanket coverage across the state without research examining the effects to the ecosystems. 

Increased wildfires in California are causing firefighters to spray more flame retardants across the affected landscapes because regulations become void during natural disasters (Forest Service n.d.).

Across the landscape, wildlife is increasingly displaced from the landscape by development, and the decreasing wildlife population are adapting to reduced native habitat.

With increased wildland urban interface, habitat loss from human actions, and less territory due to increased high intensity wildland fires, an increase in both individual and population effects can be seen. In addition to the threats associated with the loss and fragmentation of territory and loss of movement corridors, wildlife are now being exposed to more fire retardants through the blanket spraying of the environment.

Current research focuses on the acute chemical toxicity to exposed fish in waterways, however, little else has been published. On a larger scale, effects of both fires and fire retardants can cascade across the food chain (Dietrich et al., 2014). 

Compiling current research on historic fire retardant chemicals and information on longterm fire retardants it can be extrapolated that there are potential wildlife effects that have not been discovered. With longterm fire retardants, the impact across a food web can expand outside of a singular ecosystem. This is because humans move and consume wildlife in multiple locations, animals are forced to disperse during and post fire, and wildlife migrations(Klosterhauset al., n.d., Morris et al., 2018).

Plants are sessile and therefore particularly affected by wildfires at both an individual and a population level. As both victims and fuel for fires, plant-loss can be catastrophic to the ecosystem.

Adaptations to fire by plants, such as fire-resistant bark and soil insulation of seeds for future germination, allow for many plants to survive low temperature, understory flame zones (Agee, 1993).

High intensity wildfires regularly exceed 600 degrees C and while some adapted plants can withstand these temperatures, droughts and high intensity fire characteristics can exacerbate plant damage and destroy ecosystems (Agee, 1993). 

Ecosystems have adapted to allow plants to survive natural disasters via seed germination, watershed changes, and overall morphological changes throughout time.  Historically, postfire ecosystems have been able to restore native species and aquatic systems without restoration efforts from humans. 

Anthropogenic efforts attempt to restore the environment, but often do not consider fires as a benefit to these systems. Restoration are often attempts in returning the system to the previous environment despite the natural changes to water systems, plant diversity, and soil composition that is seen in historic low intensity fires. This is not a sustainable postfire management system long term (Beschta et al., 2004).

During wildfires, humans are prone to make decisions based on survival and fear. The aftermath of the fires can cause death, displacement, post-traumatic stress disorder, and other physical and emotional health problems such as smoke inhalation morbidity (Reid et al., 2016). 

Human health researchers have expressed concern that the majority of published research on human health effects of wildfires is on smoke inhalation. Gaps in research are addressed because little is known about the inhalation of fire-retardant chemicals once they are burned off by wildfires (Carratt, Flayer, Kossack, & Last, 2017). Health impacts of wildfires extend beyond smoke inhalation. Post fire conditions may reduce human access to healthcare and as a result create a disproportionate number of resources in healthcare systems (Finley et al., 2012).  

Along with reduced access comes the concern for groups of vulnerable people such as low socio-economic status, elderly, and pregnant women. Vulnerable groups may have less of an ability to evacuate these areas, compromised immune systems to handle fire conditions, or less access to technology that may warn of the need to evacuate (Finley et al., 2012).

In the Butte County  Camp Fire  of 2018, 153,336 acres (620.5 km2) were burned (an area larger than Chicago) and 50,000 people were displaced to many different areas of the country. With a large influx of people forced to move to Chico, California, a neighboring city, was also affected due to the 20% increase in population overnight. Real estate prices increased, the job market became impacted, an increase in crime, as well as other issues due to a large increase in population. Many of the people in the county moved out of California altogether in fear that a similar situation would happen in future fire seasons (Brekke, 2015).

Post fire attitudes and psychological effects have been studied in California during a 2003 study which showed 33% of people sampled had major depression, and 24% showed post-traumatic stress disorder symptoms (Finley et al., 2012). Public mindset of fire mitigation techniques rather than fire suppression is difficult to alter due to trauma and fear which can continue throughout generations (Stephens et al., 2013). 

Human safety has been researched thoroughly on amounts for label use of fire retardants. Based on extensive research by USFS on the effects of fire retardants, Napa County Health and Human Services posted an online warning stating that there is,

"Little danger in ingestion, but it should be avoided"- Phos Chek

Avoiding ingestion may not only be of concern to the residents of California, but to the recipients of California’s crops. With California providing over  400 commodities  and totaling over two thirds of the nation’s fruit and vegetables, this problem extends beyond the state border (Phos-Chek, n.d., CDFA, 2017).

In the wake of the January 2019 Camp Fire, the most destructive wildfire recorded in the state, Governor Newsom proclaimed a state of emergency and signed new fire-related bills into law. The state of emergency recognized the extreme increase in devastation of property caused by the 2017 and 2018 California wildfires and states the need for fuel reduction projects around areas where humans are at increased danger of being affected by wildfires (Newsom, 2019). Recognizing the need for increased fire suppression has spurred the use of chemicals as a solution.

Current laws reflect research conducted using long-term fire-retardant manufacturer recommendations for use (label use), which suggests that the products are within federal environmental regulations. Using past data deters policy makers from adding in new environmental regulations or further research being funded on the long-term health effects of fire retardants because it is deemed safe at label use amounts.

All current laws have contingency statements put in place to protect humans and human structures (NIFC, 2016). With wildfires continuing to threaten human life, policy alterations to reduce fire retardant as a form of suppression are less likely to change out of fear that wildfires will grow out of control. 

Safety protocols and environmental impact assessments were conducted to address the historic amounts of retardant, but the recent changes in CalFire, USFS, and the California Department of Fish and Wildlife (CDFW) regulations, and increased use of retardants, warrants new research (California Department of Forestry, n.d.). Research on the efficacy and safety of these products was conducted at lower usage amounts and for their label purposes (Stephens & Ruth, 2005). To address the current reality of increased fires, ecosystem conditions, and the expanded use of retardant, further research is needed for an overall assessment on both wildlife and human health.

Limited research has been done on the effects of human and wildlife ingestion of these products, and the decisions based on the environmental impact assessments have been conducted on more dilute levels than what is currently being used in California. Improved policies based on fire science and the findings from the environmental impact reports can be formulated by identifying the risk to human and wildlife populations and addressing the potential loss of biodiversity among the native plants.

After chemical application, chemical contact to water systems with Waters of the U.S. and Waters of the State is regulated by federal and state law, and protocols have been established to manage spills and clean up (Waters of the U.S. 33 U.S.C. 1251 et seq.,Waters of the State: Water Code section 13050(e)). Similar to oil spill prevention and regulations, fire retardants need a prevention program and a response plan tailored to longterm fire retardants in water systems (Environmental Protection Act, 2019). This would provide a check and balance that the Environmental Protection Act could implement and uphold regardless of contingency plans set forth by the state.

Within California, there are two entities that implement regulations surrounding fire suppression operations. The United States Forest Service (USFS) is the federal entity that manages USFS land across the state, including firefighting on these lands. California Department of Forestry and Fire Protection (CalFire) is the state department that fights fires on state and privately-owned land (CalFire, 2019, USFS, 2019).

Drop regulations from USFS state no dropping within 300 feet of a water source, but this mandate may be disregarded if human life or property is threatened. USFS has created retardant avoidance maps, but with waterways in California constantly changing due to the cycle of drought and heavy rains, the retardants maps are not fully accurate (United States Forest Service, n.d.).

The fire retardant avoidance map (below) shows (in red) where the USFS should avoid dropping fire retardant. Zoom in to see full avoidance areas.

In 2008, United States Fish and Wildlife Service (USFWS) recommended limiting use of fire retardants across the state. A year later in 2009, Forest Service Employees for Environmental Ethics sued USFS for not regulating fire retardant use before research-based evidence on the effects could be collected (AFUE, n.d.). The court required that the USFS conduct an environmental impact report pursuant to the National Environmental Policy Act (42 U.S.C. §§ 4321 et seq.).

In 2011, the state of California issued a Record of Decision (ROD). The guidelines contained in the ROD include a requirement that aerial application of longterm fire retardants is to be avoided within a 300-foot (or larger) buffer- or ‘no drop zone’- on either side of waterways. This guideline was created because the environmental impact report noted the runoff from longterm fire retardants were toxic to fish and aquatic life. The lawsuit resulted in an exception to the buffer which states drop zones could be ignored if human life or property was in danger (NIFC, 2016). It should be noted, however, that since the ROD, California reported in 2016 that the state outpaced federal fighting in regard to the amount of retardant used, which was an increase of 55% compared to 2013 (CalFire, 2019). 

As researched and labeled, long term fire retardant are designed to slow the fire ahead of ground crews so they can access and gain control of the fire. There is no published research that studies the effects of spraying longterm fire retardants in a different concentrations or quantities than the manufacturer labels. 

CalFire’s policies on the use of fire retardants is not reflected in the research (California Department of Forestry, n.d.). USFS in 2017 conducted another round of environmental impact reports and human impact reports with the regional aviation manager stating that there was... 

“39 years of ordering retardant drops without research on long term implications.”- Timothy Ingalsbee (Forest Service, n.d.)

Fire suppression policies in California were put into place in 1925 as a way to reduce the number of wildfires across the state. However, this policy implementation resulted in increased fuel load (e.g., understory vegetation, grasses), and high intensity fires began to occur more frequently. As a way to reduce these fires which caused more damage to the ecosystem, controlled burns or prescribed fires were used on both state and federal lands to reduce fuel load. These controlled burns usually occur in the spring when the landscape has an increase in water, and before the fire season starts (Bagne & Purcell, 2011). 

Current research has identified effects to spraying long term fire retardants in the aquatic environment. They have been found to feed harmful algal blooms along waterways and are toxic to fish (Dietrich et al., 2014). In one study, chinook salmon exhibited acute death in fresh waterways where they were directly exposed to fire retardants; and in dilute environments (simulating the ocean), gill damage was observed. The research provided evidence that runoff amounts equivalent to post-wildfire estimations caused acute death in salmon. In the more dilute ocean estimation, the salmon subjects experienced tissue damage to their gills (Dietrich et al., 2014). This is concerning to California and the ecosystems, as salmon populations are in jeopardy as a native species and are a major contributor to the native California river and ocean ecosystems (California Department of Forestry, n.d.). 

A major component to the fire retardant is fertilizer, and while that is regularly used on California soil, fertilizer has been shown to crowd out native plants and allow invasive plants to become established. While this may be an advantage to farmers for their crops, blanket spraying fertilizer over California soils will allow for invasive species to more effectively utilize the soil then endemic native plants.  Andrew Walker  from UC Davis states that fertilizer should be avoided in retardants for this reason (Cart, 2017).

Based on current environmental impact reports, both CalFire and USFS are supposed to avoid waterways due to their known effects to the water system (Stephens & Ruth, 2005). Concern for plant life and the accumulation of fire retardants on the plants itself as well as the absorption through roots and systems. Concern for invasive plants out-competing native species which could alter the ecosystem of California and reduce the biodiversity among the state and beyond. Post fire, soil exhibits water repellent conditions which creates the increased potential that fire retardants will flow into the watershed (Beschta et al., 2004). Along with the water repelling soil, water systems naturally change in post fire conditions, so it is impossible for either CalFire or USFS to know if the fire retardant will flow into a water system post application (Stephens & Ruth, 2005, Beschta et al., 2004).

Long term fire retardants are commonly what is blanket sprayed over the land and even houses during wildfires. It is designed to stay active in the environment and cling to plants until it is burned or washed away by rain. The coloring agent in water enhanced fire retardants is designed to vanish after exposure to sunlight so humans and animals cannot see the retardant after it has been sprayed (Holsapple, & Missoula Technology and Development Center, n.d.). While these properties may not be directly damaging to humans, the inability to know if the retardant is in the environment makes avoiding ingestion difficult and often impossible. 

USFS and CalFire publish an estimated budget each year that contains the amount of flame retardant that they expect to use during the next fire season based on previous years and label use specifications of the products. At the end of the year another report is published stating the amount of fire retardant actually used and recent reports show that the actual use exceeded the anticipated amount. For one CalFire facility in Sacramento, California alone, 1.7 million gallons were sprayed in 2016, and amounts increased to over 4 million from the same facility in 2017 (CalFire, 2019 & NIFC, 2016).

Each chemical used has a for label use, and the label specifies where it can be sprayed, and the effects on humans, animals, and the environment at the recommended use levels. Along with the label, each chemical has a  Material Safety Data Sheet (MSDS) sheet  that gives chemical safety information (Holsapple & Missoula Technology and Development Center, n.d.).

Chemicals are designed to assist ground crew firefighters and reduce the severity so firefighters can gain more control. Safety protocols and environmental impact assessments were conducted to address the historic amounts of retardant, but the recent changes in CalFire, USFS, and the California Department of Fish and Wildlife (CDFW) regulations warrant new research (California Department of Forestry, n.d.). Retardants are designed to target specific areas to create firebreaks and the opportunity for firefighters to manipulate the flames. However, they are now sprayed as blanket coverage across the state. Research on the efficacy and safety of these products was conducted at lower usage amounts and for their label purposes (Stephens & Ruth, 2005). To address the current reality of increased fires, ecosystem conditions, and the expanded use of retardant, research needs to be conducted to create an overall assessment on both wildlife and human health.          

Grazing management is a low-tech practice that many people in California use as their form of income and one that may also help to reduce fuel load. USFS already leases land to agriculture professionals for grazing purposes, but the land could be further utilized. Intensive management of grazing animals on the land that is not easily accessible to people is one management tool for maintaining healthy forests. Cattle are grazing animals, eating grasses, leaves, and fruit that is more homogenous in nature (Jarman, 1974). When intensively managed cattle are excellent grazers of exotic or invasive annual grasses and provide an environment where native grasses can thrive (Warnert, 2019). This means that cattle can be used to graze invasive plant life and fuel load that grows in California. Cattle use is shown to disperse in riparian zones when allowed into a new area which lessened immediate impact on the environment (Roath & Krueger, 1982). 

If riparian areas are the main source of fresh water cattle will graze the land more frequently which contain areas firefighters attempt to avoid spraying because it is close to waterways (DelCurto, Porath, Parsons, & Morrison, 2015). By removing these invasive species acting as increased fuel load, cattle can help to provide an environment for the native ecosystem to thrive (Cart, 2017). 

Goats are another livestock species that could be highly utilized as a fuel load reduction mechanism. Goats are classified as browsers, which means that they prefer heterogenous plants including bushes, stems, and mature plant material, but will also graze off the ground (Jarman, 1974). They also will eat hard to remove species that are less palatable or potentially toxic to cattle, even poison oak (Benthien, Braun, Riemann, & Stoltera, 2018). Goats also have the ability to thrive on steep surfaces, which is often where firefighters have a harder time gaining control of wildfires. 

Silvopasture methods use both trees and grazing areas to incorporate livestock onto diverse forested landscapes. This method allows for integration of non-native livestock with native plant species for intensive management that allows for more long-term sustainable grazing solutions. For this system, the movement of livestock occurs more frequently than classic rotational grazing methods, but it increases the diversity of the environment when compared to classic rotational grazing (USDA, n.d.).

Introducing livestock into an area can cause increased displacement of native species and alterations to soil and water changes that naturally occur post fires (Beschta et al., 2004). Monitoring of introduced livestock species is especially critical in post fire conditions because these species can add additional strain to the environment. Grazing should be reduced in post fire areas for 1 to 2 years to allow for the return of plant diversity (Brown & Smith, 2000). Due to livestock environmental impact, implementation of grazing as a management tool should be considered in areas of high fuel load. Pre fire livestock grazing is a mitigation tool that can be intensively managed to help reduce the severity of wildfires that the state of California is currently experiencing.

Grazing rangelands is a common practice in California with a high amount of meat production as well as range management through agriculture. By rotating both cows as grazers to eat the ground plants with goats to browse and eat brush and bushes, the fuel load could be dramatically reduced in a cost-effective manner (Warnert, 2019). Further discussions between firefighting entities, livestock owners, and environmental researchers could provide a rotational grazing schedule to reduce fuel load in high risk fire areas. 

Controlled burns or prescribed fires are currently being used as a fuel load management technique to try to reduce the number of wildfires that start near development. This preemptive measure is taken to reduce the destruction in human frequented areas. This commonly occurs on road sides, camp site areas, and urban forests. Controlled burns are designed to burn at low severity and are also a tool used in spring based on weather conditions and less opportunity for fires to get out of control (National Park Service, n.d.).These fires restore fire suppressed forests similar to historic low intensity fires providing benefits to the environment. The implementation of these prescribed fires in the spring, may compromise bird nesting sites in the short term and oak dependent bird species may be more vulnerable long term (Bagne & Purcell, 2011). Without prescribed burns, or any better management solutions, all bird species may be exposed to larger wildfires across the state, so though not without consequences. prescribed burns are still a viable long-term aid to wildfire suppression. 

Intervention on forest landscape via deliberate thinning and prescribed fires has been shown to benefit small mammals and birds because prescribed fires often mimic low intensity fire benefits. This allows for a more natural habitat restoration and increase in available habitat, however, large fuel breaks can create habitat fragmentation and concern for the overall health of the wildlife at a population level (Kalies, Chambers & Covington, 2010).

The scarcity of research on fire retardant use and its One Health effects, indicates that additional research needs to be done to fully understand the complex relationship of fire-retardant chemicals on California’s ecosystem and biodiversity. The literature indicates that not just one species is affected by fire retardant use, rather, many systems within California are regularly affected, it is just not known to what capacity and ultimate effect. By continuing the use of fire retardants without further research, California is risking its biodiversity, endemic species, and overall ecological health. 

Further research should include a longitudinal study to be conducted as well as surveillance and intensive sampling. Short term options for reducing fire retardant usage include land management techniques. Focusing research on a state that has seen both the detrimental effects of wildfires as well as an increased use of fire retardants is a good platform for research and policy alterations. Future findings on the state of California can be applied to other geographic regions that use fire retardants. To avoid spraying large amounts of fire retardants over California, the best technique is to reduce the amount of high intensity wildfires. Forest management practices in consideration of environmental, human, and animal health may return the fuel load and may return to more frequent low intensity levels. 

Research will assist California decision-makers in changes, not out of fear, but instead with knowledge of the ecosystem needs. Providing holistic care for the state will allow for long term successful solutions that can benefit humans, animals, and the environment. Research specifically looking at fire retardant safety among the ecosystems in vital. Analyzing the amounts that are being used and not at the amounts that are estimated or put on the label will provide a more accurate representation to the One Health effects. Looking for associations between type of fire retardants, volume of retardants sprayed, and pathways for bioaccumulation of these chemicals in the food web will allow for dynamic solutions. Since California is a major source of food products, a popular tourist destination worldwide, and home to many endemic species, this problem is not only reaching the animals, plants, and people who live in California, but it also affects the world. Results from future research can be used to tailor to other policies in California and create better state procedures that can be modeled worldwide. A longitudinal study on fire retardant effects should be started now, before we are potentially seeing problems within the ecosystems of California. Reflecting on chemicals that have been tried with dire consequences should motivate environmentalists, policy makers, and the state of California to support future research endeavors.

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