Firefighters around the world are facing increasingly complex challenges on the fireground, including evolving health and safety risks for the responding members of the fire service. Using statistics from the United States alone, there is compelling information available that suggests firefighting increases the risk of sudden cardiac events and the chronic risk of certain cancers.
Based on reporting from the National Fire Protection Association (NFPA) and U.S. Fire Administration, it is well established that sudden cardiac events are the leading cause of duty-related deaths among firefighters in the United States. Research has also found that sudden cardiac events are far more likely to occur after fire suppression activity. Epidemiological evidence obtained over many years indicates that the strenuous physical activity can serve as a trigger for an acute cardiac event.
Modern Firefighting Concerns
At the same time, the use of synthetic materials in homes and office buildings has increased over the last few decades. During building fires, the combustion of synthetic materials, such as insulation, furniture, and carpeting, releases toxic chemicals into the air. Uncontrolled exposure to these toxic chemicals can cause serious, adverse health effects in humans, increasing the risk of cancer, cardiovascular, and respiratory disease development, or even causing death.
Despite this evidence, and serious efforts to lessen cardiovascular disease and cancer risk in the fire service, there is a still a pressing need to gather sound information on the effects of firefighting in realistic fire scenarios on markers of cardiovascular and carcinogenic risk. To address this gap in knowledge, a recent study was conducted at the Illinois Fire Service Institute (IFSI) along with partners at Underwriters Laboratories (UL) Firefighter Safety Research Institute (FSRI), the National Institute for Occupational Safety and Health (NIOSH) and Globe Manufacturing Company.
Studying Real Fire Scenarios
The ‘Cardiovascular and Chemical Exposure Risks in Modern Firefighting’ study brings together expertise from these leading agencies in a single project. Recent work by UL has shown that temperatures during room and contents fires in buildings using typical construction materials and polymer-based furnishings found in many homes in the early 21st century increase more rapidly than temperatures reported using legacy furnishings of natural materials. Through years of research and several hundred full-scale live-fire burn tests, UL FSRI has developed a robust instrumentation suite to characterize temperatures, heat flux, pressures, gas concentrations, and visibility. However, these past studies have not had the opportunity to include firefighters – and the variability that the human element introduces – as an integral part of the outcomes. To support the current study, a fully instrumented single-story, ranch style structure based on a structure developed for a series of UL FSRI laboratory tests was constructed on the IFSI training grounds in Champaign, Illinois.
Measuring Exposures
NIOSH team members have studied firefighter exposures from a wide variety of environments, from training scenarios to diesel exhaust to small room and contents fires. These studies have characterized potential chemical exposures – particularly focusing on possible and known carcinogens and inorganic gasses – that are produced by fires, as well as measuring what is deposited on firefighting personal protective equipment (PPE) and what gets through the gear and on to the skin. Systemic exposure, measured by what is found in the firefighters’ body, has been quantified through breath, urine, and blood samples. While this data provides an important glimpse into the risks faced by the fire service, comprehensive exposure monitoring of firefighters performing typical tactics during full size structure fires with typical contents had not been performed prior to our recent study.
Physiological Responses
Research at IFSI has focused on characterizing the thermal and cardiovascular strain of firefighting activities. In particular, studies have documented changes in core temperature, plasma volume, blood chemistry, hormonal and immunological factors, heart and vessel function, and coagulatory potential in response to different firefighting scenarios. The vast majority of research investigating the physiological responses to firefighting has been done in training structures using wood and straw (Class A materials) as fuel or in laboratory conditions. These settings were the logical place to begin rigorous, well-controlled examination of physiological responses, and have conclusively shown that firefighting causes significant cardiovascular strain that could potentially trigger sudden cardiac events in vulnerable individuals. However, the physiological disruption caused by actual firefighting activities could result in even more exaggerated responses. Despite all the efforts to develop protective equipment and clothing and to devise policies and procedures to protect firefighters from exposure to the detrimental effects of heat and toxic exposures, we still do not fully understand how the modern fire environment can affect firefighter health. In addition to rapid changes in temperature, the modern fire environment also produces products of combustion containing hundreds of chemical gasses or particles with different potential toxic effects.
Until now, a detailed integration of research on fire dynamics, toxic exposures, and cardiovascular strain has been lacking. To make informed risk management decisions, the fire service needs rigorous scientific data describing the effects of firefighting in modern structures with realistic fuel loads on firefighter cardiovascular and cancer risk. Furthermore, it is important to understand how these risks are affected by firefighting tactics, riding position, and control interventions (such as field-based decontamination). The current study focuses on the intersection of each of these areas of study and does so with a focus on modern fire service response scenarios.
Research Methodology
Over the summer of 2015, firefighters from departments across the United States traveled to Champaign to participate in this study. These firefighters were deployed in teams of 12 members, operating in two person groups to conduct common functions, including Suppression, Search and Rescue, Command/Engineer, Outside Vent, and Overhaul (four members). Each group of 12 firefighters took a run at the structure using both interior attack tactics and a transitional attack approach. In all 12 scenarios were conducted with response timelines that might be expected on the modern fireground, which provided abundant data on chemical exposures, physiological changes, and fire dynamics. In addition to data obtained before and immediately after firefighting, these scenarios allowed tracking of blood, vascular, electrocardiography measures, and biological levels of contaminants for up to 12 hours after the event. This is an important component of the study given the number of sudden cardiac events that occur in the hours after emergency operations and the potential for ongoing exposure after the fire. The effectiveness of field-based decontamination of PPE and skin cleaning on reducing exposure risk was also quantified as part of
this study.
For More Information
At the time of this writing, the research team is hard at work analyzing samples, studying data, and statistically characterizing the results. An interim report is slated for release in late 2015 or early 2016, while a detailed fire service toolkit will be released in 2017. The toolkit will be made freely available to firefighters and fire officers around the globe. In the meantime, you can keep up to date with information being released by IFSI (https://www.fsi.illinois.edu/content/research/ or on Twitter @IFSIresearch) and UL FSRI (http://ulfirefightersafety.com/, https://www.facebook.com/ULfirefightersafety or on Twitter @UL_FSRI).
For more information, go to www.fsi.illinois.edu/content/research/
About the Author
Gavin Horn, PhD, Director of Research, University of Illinois Fire Service Institute.
