Cyanide poisoning poses hidden threat
By Michael Lee
The U.S. Fire Academy and the International Association of Fire Fighters have for years utilized the same NIOSH firefighter fatality statistics to assist in driving the Firefighter Wellness initiatives.
These initiatives are based on the statistics that show approximately 50 percent of fireground fatalities are caused by cardiac arrest secondary to poor fitness levels.
The statistics have caused a strong push throughout the entire fire service to encourage all firefighters to work out harder and more frequently to ensure they are able to handle the rigors demanded by the job.
But what if a portion of the fireground induced cardiac arrests where not caused by poor health but by a silent killer we have not assessed for during emergency treatment or the existing line-of-duty death investigations required for a firefighter to receive the PSOB (Public Safety Officers Benefit)?
One of the most recent theories currently being evaluated by the International Association of Fire Chiefs is the possibility of cyanide poisoning causing some portion of the cardiac arrests.
The primary concern regarding cyanide is its ability to cause fatal health issues with firefighters and the inability or unavailability of assessing for the problem.
The symptoms of cyanide poisoning mimic the signs and symptoms of a myocardial infarction.
Early signs and symptoms of exposure to low concentrations of cyanide include:
• Rapid breathing
• Eye irritation
• Pink or red skin color
• Rapid heart rate
Later signs of exposure to moderate-high concentrations include:
• Loss of consciousness
• Respiratory arrest
• Cardiac arrest
As you can see, early symptoms can masquerade as exhaustion (poor fitness?) or a cardiac event, which are often both attributed to poor fitness. These secondary symptoms may be misconstrued as a singular event initiated by a myocardial infarction when, in fact, the problem may have been caused by undiagnosed cyanide poisoning.
Cyanide is found in a large variety of household products, and is generally considered to be a natural by-product of when things such such as wool, silk and leather burn.
However, when one truly looks at the chemical make-up of the majority of household items, cyanide is part of almost every plastic-based product. Cyanide is regularly found in polyurethane, nylon, insulation, furniture cushioning, carpets and other building materials and home furnishings.
Annually, there are an estimated 20,000 residential structure fires that are caused by mattresses, pillows and bedding materials, all of which are likely to contain synthetic materials that release hydrogen cyanide when they burn or smolder. These same materials when ignited cause a fire to burn two to three times hotter and faster than natural products, causing fires to reach flashover much quicker.
Cyanide significantly impacts the evolution of both the fire dynamics and the smoke by-products of the fire and gaseous environment.
When the National Institute of Standards and Technology (NIST) investigated the Station Nightclub fire in West Warwick, Rhode Island, which caused 100 deaths in February 2003, it found 100 deaths were more than likely caused by cyanide poisoning from the burning polyurethane utilized for sound enhancement on the walls.
The NIST investigation included experiments simulating the fire in a test room with the same dimensions and containing similar materials as those in the nightclub on the night of the fire. The tests showed that within seconds of ignition of the fire, concentrations of carbon monoxide and hydrogen cyanide soared and oxygen levels plummeted.
So, if rapid levels of carbon monoxide and hydrogen cyanide are generated during the initial phase of plastics-based structure fires, and smoldering objects continue to give off-gas during the overhaul phase, how many firefighters are currently inadvertently being poisoned because routing dictates the gas monitoring of carbon monoxide only?
Current theories regarding the exposure to cyanide causes one to rethink how overhaul and post-fire gas monitoring should occur.
The death of a firefighter after tackling a small fire in Providence, R.I., last year and other incidents in the area heightened awarness of the cyanide issue
Previously, the cyanide problem had gone unrecognized by firefighters and the medical community for various reasons. For example, symptoms of cyanide poisoning are similar and commonly attributed to carbon monoxide poisoning.
In addition, the blood test for cyanide poisoning is not readily available in most hospitals. The test is blood drawn from an artery, usually the radial artery, and submitted to the lab for testing. One problem with this is that few in-house hospitals are capable of running the cyanide test. Those that are able to run the test take approximately four to six hours to get results back.
For those hospitals that are unable to test for cyanide in-house, they generally send out the test and get results back within a week. This means any necessary treatment therapy is delayed, making it useless – the half-life of cyanide in the body is one hour and if the body had an acute level, the patient will be dead before the results return.
Many of the firefighters who test normal for cyanide after fires may have had high levels of cyanide at the fire scenes and immediately thereafter, but due to the short half-life of cyanide and the length of time between the exposures and the blood draw, their cyanide levels returned to normal.
Fire departments need to evaluate post-fire scenes for cyanide as well as carbon monoxide. Even simpler, if post-fire fuels are still off-gassing, SCBAs should be worn!
Hospital physicians must be educated on the increased likelihood of firefighters presenting with cyanide induced cardiac events and, as part of their evaluations, carboxyhemaglobin and cyanide levels should be drawn as soon as possible due to the short half-live of cyanide in the blood. Also, cyanide antidote kits should be available in-house for therapy.
Finally, a line-of-duty death investigation should be required if a firefighter dies within 48 hours of a structure fire, to assist in ruling out death by cyanide poisoning.
This will drive further evaluations of firefighters that were on the same call that may be exhibiting symptoms of a lower dose of cyanide, and also also assist in securing evidence for a PSOB from the Department of Justice. The cyanide test needs to be added to the medical examiner’s list of blood work that should be completed in an LODD investigation.
The fire service is only now coming to grips with the concept of cyanide poisoning in a structure fire-based environment. We need to embrace the idea that cyanide may be killing a larger portion of firefighters than previously known.
But to track the possibility that a number of heart attacks may be caused by cyanide poisoning, we need to be sure that the proper statistics are being collected and disseminated.
We also need to embrace the idea that the new therapies may be able to reduce that number of cyanide poisonings by utilizing the new cyanide poisoning methods.
With luck, we may have stumbled upon a treatable portion of the firefighter fatality numbers that we can eradicate.
Michael Lee serves as a battalion chief in Colorado, and has more than 25 years experience in pre-hospital paramedic experience and about 20 years experience in the fire service.
- Fire Rehab