In the 1950s, the railroad industry began phasing out steam powered locomotives in favor of diesel powered
locomotives. Today, locomotives across the country are powered by diesel engines, which emit harmful diesel
What is diesel exhaust?
Diesel exhaust is a complex mixture of hundreds of hazardous particles and vapors emitted from diesel engines.
Diesel exhaust contains a number of known human carcinogens, including benzene and various hydrocarbons. Other
harmful substances such as arsenic, carbon monoxide, and formaldehyde are also contained in diesel exhaust.
What are recognized health effects of diesel exhaust exposure?
The symptoms of short term diesel exhaust exposure include irritation of the eyes, nose and throat, chest
tightness and wheezing, pulmonary function changes, headaches and light headedness, and heartburn and vomiting.
Individuals exposed to diesel exhaust can show other symptoms as well. Despite being exposed to diesel exhaust,
an individual will not likely exhibit all of these symptoms. Long term exposure to diesel exhaust can cause
significant and permanent pulmonary injuries, resulting in a shortened life span. Among the permanent injuries
diesel exhaust can cause are asthma, chronic obstructive pulmonary disease (COPD), emphysema, bladder cancer,
and lung cancer.
While research on the full effects of exposure to diesel exhaust is still ongoing, the state of California has
identified diesel exhaust as a known human carcinogen. Similarly, the Environmental Protection Agency (EPA) has
classified diesel exhaust as likely to be carcinogenic to humans, and the International Agency for Research on
Cancer (IARC) classifies diesel exhaust as probably carcinogenic to humans. The Occupational Safety and Health
Administration (OSHA) has designated diesel exhaust as a select carcinogen, and can identify no permissible
exposure level for diesel exhaust.
How are railroaders exposed to diesel exhaust?
While many railroad workers are exposed to diesel exhaust, locomotive engineers and conductors often suffer the
most significant exposures. Diesel exhaust can enter the cabs of the locomotives these workers occupy in many
ways, such as holes in the floor, cracks in the firewall, cracks in the engine manifolds, cracks in the
electrical cabinet, and broken seals around windows and doors. Often times railroad workers will work ten hours
per day, six days per week, for forty years, all the while unknowingly inhaling harmful diesel exhaust. Worse
yet, much of the diesel exhaust these workers are exposed to did not flow out of the engine stacks and back into
the locomotive cabs. Instead, because of cracks and defects in the locomotive itself, diesel exhaust flows right
from the engine compartment into the locomotive cab.
The railroads have known for years that diesel exhaust could be harmful to its workers. We have obtained minutes
of the meetings of the American Association of Railroads dating back as far as the 1960's reflecting the
railroad industry’s knowledge that exposure to diesel exhaust could injure railroaders. As concern over the
health effects of diesel exhaust exposure mounted, the Federal Railroad Administration has at least taken some
action. It authored several federal regulations to protect railroaders from diesel exhaust, among them the
requirement that products of combustion, including diesel exhaust, be released entirely outside of the
locomotive cabs. Unfortunately, these regulations are frequently ignored by railroads. Proper inspection and
maintenance of locomotives takes time in a locomotive shop. When the engine is in the shop, the wheels are not
running and revenue is not being generated. Sadly, this can result in the railroad industry’s most valuable
asset, its workers, being exposed to harmful diesel exhaust and being injured as a result.