Cars and Pollution
In the last three decades, U.S. car and commercial vehicle usage has increased three- and four-fold, respectively. While this increase in mobility has allowed a wider range of job and recreational opportunities, it has also contributed to increased levels of air pollutants. Motor vehicle emissions account for approximately 60% of the carbon monoxide(CO), more than one-quarter of the hydrocarbons (HC) and one-third of the nitrogen oxides (NOx) in our nation's air.
Carbon monoxide emissions are a result of incomplete fuel combustion. CO is a colorless, odorless gas which limits the blood's ability to transport oxygen to body tissues. This places a strain on people with weak hearts and respiratory diseases, the elderly, and pregnant women. High levels of CO can cause dizziness, headaches, impaired coordination and, at very high levels, even death.
Nitrogen oxides are the result of high temperature combustion. These pollutants can damage lung tissues and aggravate chronic lung diseases such as asthma. In addition, NOx can lower the body's resistance to respiratory infection.
Hydrocarbons are another product of incomplete combustion, and when exposed to sunlight are involved in the chemical reactions which lead to the formation of ozone. Ozone, a major component of smog, is a strong irritant to the eyes and respiratory tract. Like NOx, ozone can cause increased respiratory problems for people with asthma and other respiratory diseases.
THE ROAD TO CLEAN AIR
How is car maintenance linked to clean air? One important feature of most cars built since 1975 is the catalytic converter. When properly functioning, catalytic converters and electric engine systems can reduce the harmful emissions listed above by up to 90%. Some car owners and mechanics tamper with their emission control equipment, under the mistaken impression that performance and fuel efficiency will be improved. In fact, emission controls are integral to the functioning of your car's engine; if it has been tampered with, both performance and fuel efficiency will be reduced. Undergoing an annual emission inspection in those states where an inspection and maintenance (I/M) program is in place will help insure that your car's emission control equipment functions properly. In addition, regular tune-ups can improve fuel efficiency by up to 15% --a big savings at the pump! Using leaded gas in a car that requires unleaded gas reduces spark plug and oil filter life and damages both the exhaust system and the catalytic converter. Some car owners switch leaded gas for unleaded, trying to save pennies at the pump. In fact, using the proper fuel saves far more money than would otherwise be spent for replacement parts and repairs. This makes economic and environmental sense!
Many other components on your car (such as the spark plugs, fuel metering system, ignition timing, etc.) can also increase air pollution emissions and decrease fuel economy when they aren't functioning properly. These problems and others can be discovered and corrected by following the vehicle manufacturer's recommendations for preventative maintenance. Applying the tips described above and having your car tuned up regularly, at least once a year, will go a long way towards reducing air pollution, improving your car's performance, conserving energy, and saving you money on repairs.
[Note: This article was reprinted from the American Lung Association's "Car and Clean Air" brochure]