Diesel Exposure- A Growing Threat
The emission from diesel powered machines and engines is diesel exhaust. Many particles in diesel exhaust can cause cancer but it is not classified as carcinogen. People who are working on loading docks, bridges, farms, railroad and tunnels and workers including miners, forklift and truck drivers are at the high risk of diesel exhaust. Buses running on diesel are threat to public transportation passengers and school children. Headaches, coughing and eye irritation are few symptoms of diesel exhaust. During long-term exposure when these soot particles are inhaled into lungs, it may result to respiratory conditions, asthma and cancer. According to a study, airborne particles of diesel exhaust increases the treatment for pneumonia, lung and heart diseases.
Diesel exhaust can be defined as a contaminant in the workplaces where diesel powered equipments are used. The workers are rapidly exposed to diesel exhaust because of the increased dependency on diesel equipment. According to the study conducted by Occupational Safety and Health Administration, more than one million workers are exposed to diesel exhaust annually resulting to major health problems.
Diesel engines are largely used by railroad locomotives. Therefore, railroad workers are at the higher risk of diesel exhaust diseases. Railroad workers suffering from diesel exhaust injuries are compensated under Federal Employers Liability Act. It provides worker with compensation, disability and death benefits. Although, harmful effect of diesel exhaust exposure has been the subject of study for many years now, but railroads have done nothing or little of taking preventive measures and informing their employees about harmful effects of diesel exhaust.
Components of Diesel Exhaust
When diesel fuel is burned in diesel engine, over 9000 different components are produced. This mixture of components is known as diesel exhaust. Diesel exhaust is a mixture of various gases and particulates (soot). The various gases present in diesel exhaust are carbon monoxide, sulphur oxide, nitrogen oxide, carbon dioxide and complex compounds called aldehydes. All of these gases and compounds have been recognized as pollutant. Some of these components are hazardous and carcinogenic.
Symptoms of the Diseases caused by Diesel Exposure
The workers exposed to high levels of diesel exhaust have reported short-term health symptoms. Some of these symptoms are – lightheadedness, heartburn, headaches, numbness, weakness, irritation of eyes, nose and throat, tingling in the extremities, vomiting and wheezing. Other respiratory symptoms are bronchitis, reduced lung capacity and persistent cough and mucus. Gases like benzene, sulfur dioxide, nitrous oxide, nitrogen dioxide, formaldehyde, carbon monoxide and carbon dioxide also create health problems. The diesel exhaust component enters the body not only through respiratory system but also through the eyes. When entered through eyes, it can possibly damage optic nerve, central nervous system and brain.
Prolonged diesel exposure causes serious diseases. Diesel exhaust particulates contain small particles that can be deposited on the lungs when inhaled. These small particles carry cancer-causing chemicals known as polynuclear aromatic hydrocarbons. These particles settles on the lungs decreasing the lung function and causing shortness of breathe. According to a recent study, people who are exposed to diesel exhaust may suffer from sensory losses, equilibrium losses, memory deficits and mood swings.
Components of Diesel Exhaust
When diesel fuel is burned in diesel engine, more than 9000 different components are produced. This mixture of different components is called diesel exhaust. It is a mixture of particulates and various gases. Gases present in diesel exhaust are nitrogen oxide, sulphur oxide, carbon monoxide, carbon dioxide and complex compounds called aldehydes. All these components are pollutants and should be regulated in the workplace.
Following is the detail of some of the most hazardous components found in diesel exhaust:
Carbon Monoxide:
Carbon monoxide is composed of carbon and oxygen. It is formed as a result of incomplete combustion of diesel fuel. Carbon monoxide is tasteless, colorless and odorless. As diesel engines are more efficient, they produce less carbon dioxide as compared to gas-powered engines. The exposure of carbon monoxide on the employees working with diesel engine is greater because diesel engines have many more cylinders that are larger than automotive engines. As a result, employees are exposed to measureable levels of carbon monoxide and thus they develop tolerance for it. When exposed for several minutes and more peripheral and brain nerves become oxygen starved. This is called “carbon monoxide poisoning”.
Nitrogen Oxide:
Nitrogen oxides are compounds of oxygen and nitrogen. They are produced when nitric acid present in the diesel exhaust reacts with oxygen. Those who are not exposed to diesel exhaust chronically, nitric acid would lodge into the mucus lining without causing any medical problem. As nitric acid attaches itself to the carbon particles of diesel exhaust, it will travel to the lungs damaging hair like cells in the bronchial tubes and thus effecting lung defense mechanism.
Particulates:
Particulates are carbon based and microscopic solid particles which gets affixed to particular surface. For example, black substance inside chimney. Particulates are also called Soot. About 90% of the diesel exhaust particles are inhaled deep into the lungs. According to studies , some components found in diesel particulates are carcinogenic ( causing cancer ) and mutagenic ( causing mutations).
Sulfur Oxides:
These compounds are formed when oxygen and sulfur are combined during diesel fuel burning. During the burning process when oxygen and sulfur are combined, a dilute acid like pollutant is formed. This acid like pollutant irritates the membrane and respiratory tract and thus causing hazardous damage to defense mechanism of the body. According to the studies, an asthmatic person is extremely sensitive to such oxides and the diesel exhaust exposure may further cause injury to his respiratory system.
Hydrocarbons:
Hydrocarbons are formed by the incomplete combustion of all fossil fuels including diesel fuels. Hydrocarbons are primarily responsible for odor characteristic of diesel exhaust. These molecules are formed when hydrogen and carbon atoms are combined. They attach themselves to the particulates and thus settle deeply into the lungs.