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Air Pollution: Causes, Dangers and Prevention

There are many types of environmental pollution. Some of these types are well known (such as water pollution), while others are more obscure, (such as light pollution, noise pollution and visual pollution). One of the highest-profile types of environmental pollution, however, is air pollution.

Air pollution exists when chemical, physical or biological agents affect the atmosphere. It can be divided into outdoor and indoor types. Outdoor pollution can take various forms, including:

• acid rain
• noxious gases (e.g., sulfur dioxide, carbon monoxide, nitrogen oxides and chemical vapors)
• ozone depletion
• particulate matter or soot (also known as black carbon pollution)
• smog.

Indoor air pollution is a problem in homes, schools and workplaces and often results from suspended particulate matter and noxious gases.

Increasing traffic, expanding cities, rapid economic development and industrialization contribute to air pollution and have short- and long-term impacts on human health. Short-term effects manifest in the following ways:

• allergies
• eye, nose and throat irritation
• headaches
• nausea 
• upper respiratory infections (e.g., bronchitis and pneumonia).

Long-term effects include:

• brain, nerve, liver or kidney damage
• chronic respiratory disease
• heart disease
• lung cancer.

Short-term effects can exacerbate existing conditions such as asthma and emphysema, while prolonged exposure to air pollution can damage children's lungs and can complicate conditions in elderly people. Indoor air pollution is more likely than outdoor air pollution to affect health, but that statistic is influenced by the fact that people in industrialized nations spend some 90 percent of their time inside.

Sources of Air Pollution
While volcanoes and other natural phenomena can pollute the air, human activities also generate air pollution.

Outdoor air pollution is produced through various large-scale endeavors, including:

• agriculture
• crude oil and gas production, mining and quarrying
• electricity, gas and steam power generation
• public services (e.g., municipal incineration)
• transportation via combustion engines.

Indoor air pollution also manifests in a range of ways, including: 

• biological pollutants (e.g., animal dander or molds)
• heavy metals (airborne lead, mercury vapor, etc.)
• open-fire cooking (especially using biomass for cooking purposes)
• smoking
• volatile organic compounds (e.g., pesticides).

Many of these air-pollution-producing elements are entrenched in daily living, and while much has been done to address the effects of engines, industry and lead and mercury on the air, we can still do more in regards to agriculture and the indoor use of biomass, a prevalent practice in developing countries.

Air Pollution: The Good, The Bad, The Scary
There has been progress with air pollution. For example, since 1970, the United States has slashed air pollutants by more than fifty million tons. Furthermore, today, twenty cars generate the same amount of air pollution as one mid-1960s model car. However, there remains a lot to be concerned about, including the following:

• An estimated 4.9 million people die from smoking annually.
• A ship at dock unloading its cargo releases a ton of smog-forming and toxic pollutants every day.
• Asthma is a leading cause of school absenteeism.
  Breathing air in polluted metropolitan areas can reduce your life expectancy by two to three years.
• Ground-level ozone is responsible for about $500 million dollars in reduced crop production annually.
• In California, health impacts from diesel pollution exposure, such as premature death, heart disease, asthma and bronchitis, cost some $22 billion.
• Living, working or going to school near freeways, high-traffic roads, seaports and rail yards puts you at a greater risk for cancer and decreased lung function.
• Motor vehicles, other means of transportation and even lawnmowers present a much higher cancer risk than stationary sources such as power plants and factories.
• The Environmental Protection Agency has declared that diesel exhaust contains more than forty hazardous air pollutants.
• When you drive in heavy traffic, pollutants can seep into your car, making the air inside it up to ten times more polluted than typical city air.
• Toxic air pollution is a big problem for children, in part because they breathe much more quickly than adults.
• You may not smoke, but exposure to ozone and particulate matter can damage your lungs and heart.

Car Pollution Facts
Motor vehicles are responsible for an estimated 14 percent of the world's carbon dioxide emissions. Cars also emit more than 1,000 pollutants. Indirectly, cars pollute via oil production and during automotive manufacture and disposal. In fact, the production of a car generates more pollution than a car does during its entire lifetime.

Air Pollution Impacting Earth
Air pollution can alter the planet's ecosystem in various ways. The greenhouse effect is the process whereby the Earth's surface is heated by both atmospheric infrared radiation and solar radiation. While this is a natural phenomenon, the greenhouse effect is exacerbated by greenhouse gases (carbon dioxide, methane and aerosols) that are emitted by human activities.

Ozone depletion is another way that air pollution is changing the Earth's ecosystem. Ozone depletion exposes the planet to ultraviolet rays that can harm the global food chain. Air pollution also contributes to acid rain, which affects surface water and aquatic animals, decreasing biodiversity and also damaging food chains.

What Can Be Done About Air Pollution
As with other types of environmental pollution, government action on the local, regional and international level is crucial to air pollution prevention efforts. Controls and restrictions must be set, and regulatory agencies must monitor air pollution levels.

Air pollution can be fought at the microlevel too. Here are a few steps you can take to fight air pollution:

• Carpool, bike, telecommute, walk or use mass transit.
• Don't smoke.
• Drive smarter.
• Purchase an efficient, low-polluting car.
• Reduce waste by reusing and recycling products.
• Reduce particulate matter.
• Save energy and conserve water.
• Use air-friendly products.

Air pollution is a complicated world problem confronting governments and nongovernmental organizations, but by doing a few simple things, you can make a big impact on the quality of the air you breathe.