Firefighters are exposed to many contaminants throughout their careers, some of which are better understood than others. For example, carbon monoxide is a single gaseous compound. The health effects of overexposure to carbon monoxide have been studied for many years and are well understood. It is easily tested in the air using convenient electronic monitoring equipment. One can compare the results of that testing with the established Occupational Safety and Health Administration (OSHA) workplace Permissible Exposure Limit (PEL) of 50 parts per million (PPM) in air, to easily determine whether there is a likely health-hazardous overexposure.
Diesel exhaust, on the other hand, is a complex smoke mixture, which contains dozens of compounds including both gases and particles. Diesel exhaust is not a simple workplace air contaminant, as is carbon monoxide.
There is no test method, OSHA PEL, or other reference exposure level for diesel exhaust as a whole. Currently, only the individual components can be considered. Although there is an OSHA PEL for some diesel exhaust components, such as carbon monoxide, nitrogen dioxide and benzene, there are many other diesel exhaust components of concern. Adding additional complexity, there are no generally agreed-upon methods by which to test the air for many individual diesel exhaust components. As a result, diesel exhaust is much more difficult to evaluate than simpler workplace air contaminants such as carbon monoxide alone.
Firefighters are exposed to diesel exhaust both in the station, as equipment starts up/leaves and enters the station, and in the field, as equipment idles during a response. In the field, they may also be exposed to other sources of smoke and associated contaminants, both during initial fire response and during overhaul. Unique to many firefighters is that they both work and live in the fire station, sometimes for periods of 24 or 48 hours or longer, which increases the potential duration of exposure.
Finally, the cumulative health risks of exposure to diesel exhaust are long-term and can come from various sources in the workplace, as well as more widely in the general environment. Those risks are therefore more difficult to identify and treat than a more immediate health risk such as from carbon monoxide.
Diesel exhaust health risks
OSHA, in its 2013 “Hazard Alert for Diesel Exhaust/Diesel Particulate Matter,” identifies short-term health effects from exposure to high concentrations of diesel exhaust and diesel particulate matter (DPM) that may include headache, dizziness, and irritation of the eye, nose and throat. OSHA also identifies prolonged diesel exhaust and DPM exposure as increasing the risks of cardiovascular, cardiopulmonary and respiratory disease, and lung cancer.
The evidence for diesel exhaust as a carcinogen (cancer-causing material) is relatively strong:
- Environmental Protection Agency (EPA) – Diesel Exhaust “likely to be carcinogenic to humans” (2003)
- National Toxicology Program (NTP) – Diesel Particulate Matter “reasonably anticipated to be a human carcinogen” (2000)
- International Agency for Research on Cancer (IARC) – Diesel Engine Exhaust “carcinogenic to humans (Group 1)” (2012)
In addition, firefighters are exposed to other hazardous chemicals and carcinogens from smoke associated with fire response and overhaul. IARC Group 1 carcinogens in smoke (not specific to diesel exhaust) include arsenic, asbestos, benzene, benzo(a)pyrene, 1-3 butadiene, soot and dioxins. IARC Group 2 carcinogens in smoke (again, not specific to diesel exhaust) include creosote, PCBs and 1-nitropyrene.
A NIOSH study of approximately 30,000 career firefighters over nearly 60 years (1950 through 2009) showed an overall excess in cancer incidence and mortality, including related to lung cancer. This study did not focus exclusively on diesel exhaust; therefore, it is important that fire departments do not focus exclusively on the control of diesel exhaust for the protection of their personnel from these health risks. However, while diesel exhaust is not a singular issue, the prevention of overexposure to diesel exhaust is a very important control consideration.
Ultimately, the study of the health risks associated with diesel exhaust is relatively new, compared with the study of the health risks related to a simple workplace air contaminant such as carbon monoxide. There are many uncertainties in the nature, magnitude and behavior of the health risks associated with diesel exhaust (and smoke more generally), and the overall understanding of those risks is evolving relatively rapidly.
Potential short- and long-term impacts on fire departments
As the understanding of the risks of exposure to diesel exhaust evolves, case law around workers’ compensation claims for lung cancer and other illness related to diesel exhaust exposure is also evolving, as is the related toxic tort law. This latter, costlier, litigation is directed primarily toward manufacturers of diesel-powered equipment. However, fire departments should be aware that volunteer firefighters, who may not be covered by workers’ compensation laws, may be able to sue their department for lung cancer or other illness that they claim has resulted from their work for the department. Additionally, a strategy that has been explored in the defense of claims against equipment manufacturers is to bring a third-party claim against the plaintiff’s employer. Such third-party actions may focus, for instance, on a failure of the employer to adequately maintain diesel-powered equipment.
Recent firefighter cancer risk studies, combined with the evolution of litigation related to diesel exhaust exposure, have shined a beacon of light on the urgency of exposure reduction. Cities, departments, unions and individual firefighters are becoming better educated and have an increased desire for knowledge as they strive to understand how to mitigate these risks. Personal education, and the application of situational awareness strategies relative to health and welfare in the fire station, are becoming more commonplace when talking to firefighters.
With a simple online search, considerable information is available, through studies, articles, reports, blogs, support networks, and personal stories. We have witnessed that with information comes power—the power to improve working conditions, poor habits, and industry standards. Since evolving design strategies relative to ventilation, exhaust, cleaning, decontamination, and functional separation can sometimes come at significant cost, necessity becomes the mother of invention.
To start, continue to ask how design can be improved. How it can be done more cost-effectively. Consider how relatively simple changes in day-to-day activities can improve firefighter health. Strive to inspire change and question how others are addressing these concerns. This is not an exact science yet, but there is a wealth of information being shared both nationally and internationally. Educate yourself and share research, information, and your success stories.
Cancer risks related to diesel exhaust and other sources of fire department exposures to carcinogens, along with the associated impacts on firefighters and departments, is a moving target that is difficult to predict and therefore may seem impossible to manage. Multiple types of control technologies are available, and these are also rapidly changing. It may seem an insurmountable task to protect firefighters and manage fire department liabilities. However, this issue can be managed, even in the absence of answers to all the possible questions and in the face of evolving information and technology.
This is only the introduction. The five articles that follow in this six-part series will provide you with information and resources to enable you to make better employee protection and liability control decisions, and to put the control of these risks into a manageable framework.
Related Articles:
- Confronting Fire Department Diesel Exhaust Exposure Concerns - Part 1
- Confronting Fire Department Diesel Exhaust Exposure Concerns - Part 2: Taking a Systems Approach
- Confronting Fire Department Diesel Exhaust Exposure Concerns—Part 3: Determining Exposure Sources
- Confronting Fire Department Diesel Exhaust Exposure Concerns - Part 4: Evaluating Exposure Pathways
- Confronting Fire Department Diesel Exhaust Exposure Concerns - Part 5: Maximizing Your Resources
- Confronting Fire Department Diesel Exhaust Exposure Concerns - Part 6: Air Testing & Communication of Exposure Results
- Confronting Turnout Gear, Equipment Contamination in the Fire Station
