Air is a resource shared by all. Unlike water, which can be collected and distributed through pipes, air circulates around the entire globe, unrestricted by most physical barriers. More so than any other resource, all of us share the air, and the amount to which we benefit from this resource depends on how we treat it.
How do we manage a resource that belongs to everyone?
A popular analogy for a common resource was invoked by ecologist Garrett Hardin in 1968—“The Tragedy of the Commons”. In his work, Hardin described the consequences of the human tendency to act in one’s own self-interest and ignore what is best for the group as a whole. More specifically, this phenomenon implies that an increase in human population creates increased strain on finite resources, which jeopardizes sustainability, thus resulting in a tragedy of the commons.
What is Air Pollution?
Air pollution occurs when harmful or irritating gases, dust, fumes, or odors become concentrated in the atmosphere in amounts that can harm living things, damage human or natural materials or systems, or cause some other kind of nuisance. These harmful materials in the air are called air contaminants.
For generations, people believed the atmosphere to be large enough to absorb anything we put into it. Although this may have been at least partly true at one point in time, human population is much larger now than it once was and human activities have taken a tremendous toll on the quality of our air.
Types of Air Pollution
Smog is a broad term that includes most outdoor air pollution, including smoke, particles, and air contaminants. A common ingredient in smog is ozone—an air contaminant made up of three oxygen molecules, an unstable arrangement making it very easy to react with other materials. In the upper atmosphere, ozone protects us from excess radiation from the sun. However, on the earth’s surface, ozone can be harmful to the lungs and has been linked with many illnesses including asthma and heart disease. Vehicles, factories, and electricity generation create pollution when fossil fuels are burned, as well as through the evaporation of paints and chemicals used in production. Indoor air pollution occurs when chemicals evaporate through human use of cleaning products, personal care products like hairspray, and even off-gassing from building materials.
In the developing world, biomass—crop husks, straw, dried animal dung, or wood is often used for cooking and heating. Smoke and soot from these processes create particulate matter, a term used to describe tiny unwanted particles suspended in the air. Oftentimes, with smoke and other pollutants, these particles are so small that they can be absorbed into the bloodstream, causing adverse effects on cardiovascular and respiratory systems. Because of these stoves, air pollution has become the leading cause of early death, outpacing a lack of clean water and poor sanitation.
The Clean Air Act
The U.S. Federal Clean Air Act was enacted by congress in 1963 with the purpose of reducing air pollution from stationary sources such as power plants and steel mills. According to the Environmental Protection Agency (EPA), the Clean Air Act is the law that defines the EPA's responsibilities for protecting and improving the nation's air quality and the stratospheric ozone layer. Among other things, the Clean Air Act limits the amount of ozone that can reside in the atmosphere at ground level.
The Clean Air Act was one of the United States' first and most influential modern environmental laws, and remains one of the most comprehensive air quality laws in the world. For more than forty-five years the Clean Air Act has cut pollution as the U.S. economy has grown. Improvements to this law and others like it have continued to be made over time. According to the EPA, Clean Air Act programs have lowered levels of six common pollutants (particles, ozone, lead, carbon monoxide, nitrogen dioxide and sulfur dioxide) as well as numerous toxic pollutants.