Beware Locomotive Exhaust

by: Jay A Kaplan

If you are required to be confined in diesel locomotive cabs on a constant basis without proper protection, you very well may be being exposed to significant health risks. To understand and appreciate these risks, one must first know what diesel exhaust is and the harmful effects it can produce in the work environment. Although the harmful effects upon railroad workers of exposure to diesel exhaust has been the subject of several studies and has been known for many years, most of the railroads, unfortunately, have done little or nothing about taking preventive measures, or, for that matter, even informing their employees of the hazards.

Diesel exhaust is a mixture of over 9.000 different components which are produced when diesel fuel is burned in a diesel engine. Diesel exhaust is made up of particulates (soot) and various gases. The most prevalent gases that are present are sulfur oxides, nitrogen oxides, carbon dioxide, carbon monoxide and various complex compounds called aldehydes. Each one of these has been recognized as pollutants and should be regulated in the workplace even if they have not been sufficiently regulated in the overall environment.

Unfortunately, many of the other substances present in diesel exhaust are extremely complex, not properly identified and thereby go vastly unregulated. While it is true that some of these substances are not harmful to the human body, others previously mentioned are potentially very dangerous and carcinogenic (cancer causing). Recent studies suggest that in the worst case scenario, railroad workers, because of their exposure to diesel exhaust, could develop various types of cancers such as to the lungs or the bladder within several years of their initial exposure. In fact, IARC classifies diesel exhaust as a 2 A probable human carcinogen. Additionally, diesel exhaust has been known to cause damage to the respiratory system and result in chronic lung ailments, Recent studies have suggested that it may also cause industrial asthma as well as RADS (Reactive airways Disease Syndrome) with chronic exposure. Typical symptoms presented would be shortness of breath, burning chest pain, wheezing, dry cough, etc.

Less well known is the fact that, in addition to entering the body through the respiratory system (breathing), harmful diesel exhaust components can enter the body through the eyes, possibly causing permanent damage to the optic nerve, and possibly even to the brain and central nervous system.

In order to be informed about the potentially harmful effects of being exposed to diesel exhaust while at work, it is important to have at least a rudimentary understanding of some of the main components and the health risks that each one can present to each and everyone of you on the job. The following is a brief description of some of the most prevalent and potentially hazardous ones.

Particulates - are microscopic, carbon based solid particles which can become affixed to a particular surface like soot does to the inside of a chimney. Approximately 90% of diesel emission particulates can be inhaled into the respiratory system and into the deep lung where they may remain for days. Studies have shown that some of the compounds in diesel particulates are mutagens, (things that can change genes) and carcinogens, and, as a result, there can be an interference with the reproduction of lung cells and a loss or reduction of lung function.

Carbon monoxide - is a gas which is composed of carbon and oxygen and is formed as a consequence of incomplete combustion. By itself, it is colorless, odorless and tasteless. No matter how efficient or how well tuned an engine is, there is always a portion of the fuel that is not completely burned on each power stroke (combustion stroke) in each cylinder of the engine. Although diesel engines are generally more efficient and thus produce less carbon monoxide per measure of fuel than do gas powered engines because they have so many more cylinders that are so much larger than those of an automotive engine, the overall exposure to railroaders can be far greater. The human body cares about (is effected by) the finite levels of carbon monoxide to which it is exposed, not the numbers of engine cylinders it took to produce it. As a consequence, railroaders riding in unprotected units may suffer chronic exposure to measurable levels of carbon monoxide and ironically develop a tolerance for it. Since it is colorless, odorless and tasteless, carbon monoxide can "fool" the body because it is unable to distinguish it from oxygen which is also colorless, odorless and tasteless. When there is intense exposure for several minutes or more as, for example, inside a tunnel or confined spaces like a roundhouse or even narrow deep canyons, the brain and peripheral nerves can become oxygen starved. This is called, "carbon monoxide poisoning" and in certain cases, permanent irreversible nerve and brain damage can occur. Classic symptoms of carbon monoxide poisoning are persistent headaches, dizziness and light-headedness, loss of mental alertness and muscular strength, ear, and eye damage and damage to the peripheral nerve system, etc.

Nitrogen Oxides (NOX's) - are compounds of nitrogen and oxygen which are produced when the nitric acid present in diesel exhaust reacts with oxygen. For person not performing jobs around diesel exhaust as so many railroaders do, the nitrogen oxide will usually be absorbed into the mucus lining of the upper respiratory tract without causing any significant medical problems. However, if it attaches itself to the carbon particles (soot) of diesel exhaust, it will be able to travel significantly further into the lungs, it has been shown to cause damage to the hair like cells in the bronchial tubes and thereby cause damage to the lungs defense mechanism. Studies have also demonstrated that NOX's increase pulmonary response to irritants.

Sulfur oxides - are compounds that are formed when sulfur and oxygen are combined during the burning of diesel fuel you have all heard of, sulfur acid. When sulfur and oxygen are combined, they form a dilute acid like pollutant which can irritate the membranes that line the respiratory tract and thereby can cause damage to the body's defense mechanisms. It has been shown that person who are asthmatics may be extremely sensitive to such oxides and thereby suffer further injury to their respiratory system as a result of such exposure.

Hydrocarbons - like carbon monoxide are cause by the incomplete combustion of all fossil fuels including diesel fuel. It is the hydrocarbons that are primarily responsible for the characteristic odor of diesel exhaust. Hydrocarbons, which are molecules that are formed when carbon and hydrogen atoms combine, can attach themselves to diesel particulates and thereby find their way deep into the lungs.


Various studies over the years have demonstrated that exposure to diesel exhaust has resulted in significant health risks to workers such as those in the railroad industry who are routinely exposed to such risks while at work. In fact, as recently as 1993, one study reported three independent occurring cases of Reactive Airways Disease (RADS) following acute, heavy exposure to diesel exhaust. The study suggested that the exposure was associated with the disconnecting of cabooses and the resultant placing of the crew and/or"deadheading" crew into a trailing unit behind the head unit and exposing them to the continual blowing of exhaust into the cab in which they were riding. As stated previously, studies and medical literature have suggested that exposure to diesel exhaust may cause a host of more serious medical problems such as lung or bladder cancer since carcinogenic compounds can be easily inhaled into the lungs or even swallowed and thereby drawn into the gastrointestinal tract and lymphatic system. Other studies have additionally demonstrated that exposure can adversely affect the internal organs such as one's heart. In response to these studies, the railroads, like the tobacco industry, have sought to escape culpability and liability by advancing their typical argument that the medical proof that diesel exposure results in injury to their workers is "at best" inconclusive. The railroads continue to claim that many of the medical aliments of railroad workers are due to smoking, exposure to passive smoke, pre-existing medical problems or exposure to other toxic and/or carcinogens outside the workplace rather than to the known exposure regularly occurring in the workplace.


Under the Federal Employers Liability Act ("FELA"), a railroad has a duty to exercise ordinary care under the circumstances to provide its employees with a reasonably safe place within which to work. Court decisions interpreting the FELA have held that the railroads owe a duty to provide reasonably safe and suitable tools, machinery and appliances with which to work, to institute and oversee reasonably safe methods for the performance of work, and to warn of potential dangers and hazardous conditions, etc.

In 1991, the Boiler Inspection Act (BIA) (also known as the Locomotive Inspection Act) was enacted. This statute which applies principally to locomotive engineers and other operating department employees who must work in and on engine locomotives that are "in service" (not being repaired), imposed an absolute duty on a railroad carrier for violation of its requirements which the railroad cannot escape by claiming that it exercised some degree of care. The Act "imposes upon the carrier an absolute and continuing duty to maintain the locomotive and all parts and appurtenances thereof, in proper condition, and safe to operate...... without unnecessary peril to life or limb". Under the BIA, unlike the FELA, the possible contributory negligence of the worker himself is neither a defense nor an issue if the defendant is found to have violated the statute. The violations of the FELA and BIA by the various railroads have been argued many times in Court by our law firm when handling cases of railroad workers that have been exposed to diesel exhaust. It has been our contention among others, in these cases that the defendant railroad violated one or both of these Acts by failing to have the engine compartment windows and doors properly sealed so as to properly prevent the seepage of exhaust fumes into the cab, or failed to install respirators, ventilators or properly working safety masks on units so as to protect the employees against continuous exposure. In other cases, we have been able to successfully argue that the violating railroad failed to properly train its workers as to what to do if exposed to significant amounts of diesel exhaust, or that it negligently failed to have an appropriate safety plan in existence for such circumstances.

As a final note, this article is not meant to offer specific medical or legal advice about a given individual situation, but rather to afford to the reader a general overview of the potential health risks to which he or she may be exposed at work and some of the legal remedies that are generally available. Accompanying this article is a general bibliography that has previously been supplied to the writer of this article as a member of the Academy of Rail Labor Attorneys. Should you have any specific questions concerning exposure to diesel exhaust or your rights as a railroad worker under the FELA or BIA, please feel free to contact the author of this article.

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