By Mary Jane Dittmar
Fire Engineering and FireEngineering.com
It is common knowledge that diesel exhaust poses dangers to human health. Diesel is one of many hazardous materials to which firefighters are exposed; it may be one of your most common exposures.
The New Jersey Department of Health Public Employees Occupational Safety and Health Program (PEOSHG) notes that the idling of diesel fire trucks inside the fire station can cause the exhaust generated to spread throughout the station and settle on walls, food, and clothing, affecting the health of those who breathe in the exhaust.1
Diesel fuel is particularly dangerous because it contains more than 40 substances that are considered toxic.2 Diesel exhaust emissions (diesel fumes) are a mixture of gases, vapors, liquid aerosols, and substances made up of particles. Among the products of combustion they contain are carbon (soot), nitrogen, water, carbon monoxide, aldehydes, nitrogen dioxide, and sulphur dioxide. Soot content can vary from 60 percent to 80 percent depending on the fuel used and the type of engine.3 Polynuclear aromatic hydrocarbons (PAH), also found on diesel particulates, are potential health hazards. (1)
The composition of diesel fumes is affected by the quality of the diesel fuel used, the type of engine (standard, turbo, or injector), the state of the engine’s tuning, the fuel pump setting, the workload demand on the engine, the engine temperature, and the degree to which the engine is regularly maintained. (3)
Effects of Exposure
In one study, personal sampling techniques were used to evaluate the exposures of New York, Boston, and Los Angeles firefighters to particulates from diesel engine exhaust. It was found that the more alarms to which the firefighters responded, the higher their exposure to the particulates. When there were between seven and 15 alarms during an eight-hour shift, exposure levels of total airborne particulates from diesel exhaust ranged from 170 to 480 µg/m3 (micrograms per cubic meter of air) averaged over eight hours. (1) PEOSHG explains that this level value can be better understood when compared with outside levels in those areas. In New York and Boston, air measurements for particulates during this study ranged from 30 to 60 µg/m3. Moreover, PEOSHG noted, the outdoor levels would be expected to contain a variety of particulates, whereas the particulate levels in the fire stations probably contained a higher percentage of particulates from diesel exhaust and thus would have a higher percentage of PAH.
Exposure to the fumes can irritate your eyes and respiratory tract. These conditions usually are short term and should disappear when you are away from the exposure source, but prolonged exposure to diesel fumes-in particular when you see blue or black smoke (see below)-could cause coughing, breathlessness (3), headaches, eye irritation, nausea, vomiting, numbness, wheezing, heartburn, and chest tightness. (1) In the long term, some evidence has shown that repeated exposure to diesel fumes over a period of about 20 years may increase the risk of lung cancer. If cold diesel contacts the skin, dermatitis may result. (3)
The National Institute for Occupational Safety and Health (NIOSH) concluded in its “Current Intelligence Bulletin 50, “Carcinogenic Effects of Exposure to Diesel Exhaust” (August 1988), that toxicological and epidemiological findings suggest a “potential occupational carcinogenic hazard exists in human exposure to diesel exhaust.” (1)
An analysis by the State and Territorial Air Pollution Program Administrators and the Association of Local Air Pollution Control Officials indicates that over a lifetime of exposure to diesel fumes, an estimated 119,570 people in metropolitan areas and an additional 5,540 in suburban and rural areas will develop cancer.4
According to the American Lung Association of California, diesel exhaust exacerbates lung diseases such as asthma and emphysema.”5 (to be continued)
- “Diesel Exhaust in Fire Stations,” Public Employees Occupational Safety and Health Program, New Jersey Department of Health, May 1994.
- “Dangers of Diesel,” State PIRGs (Public Interest Research Group) Working Together, http://pirg.org/. The state PIRGs are state-based, citizen-funded organizations that advocate for the public interest.
- “Diesel Engine Exhaust Emission,” Health & Safety Executive, Health and Safety Commission (HSC), Great Britain, http://www.hse.gov.uk/.
- “Diesel Fumes Mean Cancer for Thousands of Americans, Cat Lazaroff, Lycos Environment News Service, March 15, 2000.
- “There’s Even More You Should Know About Diesel,” American Lung Association of California, May 2002.