When you see a car driving down the road and there is what appears to be black smoke billowing from the tailpipe, it may become perfectly obvious to you that cars release some form of pollution into the air. The pollutants cars emit can be broken down into four different categories: carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter.
Often scientists will focus on carbon dioxide when talking about environmental issues; however, carbon monoxide is also a member of the carbon family that is cause for notice. Cars emit carbon monoxide, and when organisms such as humans and animals are exposed to carbon monoxide, it impedes their ability to carry oxygen in their blood. This means that important organs such as the heart and the brain may not be getting enough oxygen.
Cars also emit hydrocarbons. According to the U.S. Environmental Protection Agency, there are many forms of hydrocarbons and these hydrocarbons are created when products like coal, oil, or gas are only partially burned. These hydrocarbons linger in the environment and can pose health risks to humans. For example, they can damage the respiratory system and lead to an increase in certain types of cancer.
Nitrogen oxides are often found in their highest quantities alongside busy roadways, according to the EPA, and there are many byproducts that arise from cars releasing oxides of nitrogen into the environment. Smog formation, acid rain and damage to vegetation are three of many environmental issues the United Kingdom's Vehicle Certification Agency (VCA) lists. Beyond the environment, nitrogen oxides can also cause harm to the respiratory system. Long-term exposure to oxides of nitrogen may permanently damage lung function.
When you see a diesel car with a trail of billowing smoke, you are seeing it release particulate matter into the environment. Particulate matter is a group of extremely fine particles such as nitrates, sulfates, organic chemicals, metals and soil or dust particles. If the particles are small enough (10 micrometers in diameter and smaller), respiratory and cardiovascular problems are likely to increase because the particulates can easily pass through the throat and nose to the lungs, according to the EPA.
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