Effects of Car Exhaust

Automobile engine exhaust has been blamed for everything from cancer to the melting of polar ice caps, but what are its true effects? In theory, a pure internal combustion process event would produce only carbon dioxide and water, but the actual output of an engine is much more complex. Inefficient combustion, additives in gasoline and nitrogen in the air itself all lead to unwanted emissions that have varying effects on both the environment and the individual.

Carbon Dioxide

The most notorious and well-known component of internal combustion is carbon dioxide (CO2). This natural byproduct of the combustion event is considered a major greenhouse gas. Greenhouse gases collect in the upper atmosphere and trap the sun's heat, leading to an overall increase in global temperature. This effect is more concentrated in some places than others.

Carbon monoxide (CO) is a close cousin of carbon dioxide, and its dangers are a little more localized than those of its kin. When inhaled in quantities as low as 667 ppm (parts per million), CO begins to convert up to 50 percent of the body's oxygen-carrying hemoglobin to carboxyhemoglobin. This molecule is ineffective at delivering oxygen to the cells, and leads to an effect similar to strangulation. The immediate effects of CO poisoning are headache, nausea, drowsiness and ultimately death.

The extremely high combustion chamber temperatures of high-compression and turbo-charged engines often produce nitric oxides (NO and NO2). In small doses, nitric oxides play an important role in cellular communication and help to protect the liver. However, large doses of NOs are known to cause vascular collapse and septic shock. Chronic inhalation of NOs have been linked to arthritis, ulcerative colitis, juvenile diabetes, birth defects/DNA mutation and multiple sclerosis.

Studies conducted by Environmental Health Perspectives in 1999 have concluded that lab mice who were exposed to a minuscule 12 ppm of NOs for six hours a day over a period of three months developed severe endocrine (hormonal) disorders. The effects of these disorders include a low sperm count and inhibition of several growth hormones.

The environmental effects of automobile exhaust are essentially a macrocosm of the changes caused in an individual. NOs float into the upper atmosphere to form nitric acid, which is a major component of acid rain and smog. When that rain hits the ground, it leaches into the soil, and thus the groundwater.

Unburned hydrocarbons (gasoline) from the exhaust present a similar danger to the groundwater and soil, as they are heavier than air and will immediately settle to the earth. If you've ever witnessed the effect used motor oil has on grass, then you have a pretty good idea of what hydrocarbons can do to anything still living.