Motor Vehicle Emissions & Air Pollution

Air pollution comes from factories, businesses, consumer products, cars, trucks and buses. Pollution from vehicles causes two of our worst air pollution problems, smog, or low-level ozone, and carbon monoxide.

Ozone is a colorless gas, which is composed of three oxygen atoms linked together. When found in the upper atmosphere, it is a natural barrier to the harmful rays of the sun. When found at ground level, it can be a hazard to the health of humans, animals and plants.

Ozone is formed when volatile organic compounds (VOCs) and nitrogen oxides (NOx) react during a warm, sunny day. Industry, gasoline fumes, vehicle exhaust, chemical solvents, and natural resources generally release VOCs and NOx which are known to cause ozone at ground level .

Ozone affects ones' health by damaging lung tissue and making them more susceptible to infections. Ozone is also known to aggravate already existing health problems, such as asthma, heart disease and emphysema. It can also inhibit the growth of plants, cause damage to crops, crack the seal of rubber and adhesives, and cause dyes to fade.

On days that ozone levels are high (hot, summer days, with no wind), residents should try to reduce the amount of time spent outdoors and should avoid most outdoor exercise. People with asthma or other respiratory problems should be especially careful of exposure on bad days. Information on ozone levels on particular days can be obtained from the DEQ web site at ozone from the DEQ Air Quality Update Line at (225)-219-3543. Other ozone information can also be found at

Carbon Monoxide (CO) is a colorless, odorless, poisonous gas. A product of incomplete burning of hydrocarbon-based fuels, carbon monoxide consists of a carbon atom and an oxygen atom linked together.

Carbon Monoxide forms when there is an incomplete combustion of fuel and is emitted from the tailpipes of vehicles. When vehicles are not tuned well, the air supply in the car is restricted during starting and incomplete combustion occurs. Two-thirds of the existing CO emissions found in the air are caused by transportation sources.

Carbon Monoxide interferes with the blood's ability to carry oxygen to the brain. CO can slow reflexes and affect thinking skills. Pregnant women and people with heart or lung disease are particularly at risk. In high concentrations, carbon monoxide kills. More information about carbon monoxide and other air pollutants can be found on the EPA page at

Louisiana Department of Environmental Quality 602 N. Fifth Street Baton Rouge, LA 70802
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