Air pollution can have a number of devastating effects on human health, property, and ecosystems.
The following are some of the most common examples of damage caused by this form of pollution.
Toxic Air Pollutants
Toxic or hazardous air pollutants are a category of pollutants that are known to cause serious health problems or adverse environmental effects. Most of the toxic air pollutants come from anthropogenic sources such as cars, factories, building materials, and cleaning products.
Some hazardous air pollutants can be released from natural sources such as volcanic eruptions and forest fires. People can be exposed to toxic air pollutants by:
- Breathing contaminated air.
- Eating contaminated food products, such as fish from contaminated waters; meat, milk, or eggs from animals that fed on contaminated plants; and fruits and vegetables grown in contaminated soil on which air toxins have been deposited.
- Drinking water contaminated by toxic air pollutants.
- Ingesting contaminated soil. Young children are especially vulnerable because they often ingest soil from their hands or from objects they place in their mouths.
- Touching (making skin contact with) contaminated soil, dust, or water (for example, during recreational use of contaminated water bodies).
Some persistent toxic air pollutants can experience biological magnification through an ecosystem.
Exposure to air pollutants can cause a variety of health problems such as damage to the nervous system, damage to the immune system, issues with fertility and reproduction, birth defects, developmental issues, and most commonly respiratory disease. Although not fatal, chronic bronchitis and asthma are two common afflictions that seriously impact human health due to air pollution. Chronic bronchitis and asthma are caused by particulate matter, oxides, and acids of sulfur and nitrogen.
Both of these conditions cause persistent inflammation of the bronchial linings that can eventually make breathing difficult. Lung cancer and emphysema are two more serious and sometimes fatal conditions that are caused by exposure to air pollutants.
Because of the concentration of population and motorized vehicles, cities often have high levels of air pollution. Non-smokers who live in urban areas are 3 to 4 times more likely to develop lung cancer than non-smokers in rural areas.
The EPA has identified 187 pollutants that they deem as toxic. Their goal is to reduce the emissions of these hazardous substances in our homes and environment.
This is done through regulations on emissions from major industrial sources, mobile sources, and close monitoring of emissions that might affect indoor air quality. The EPA monitors and alerts the public to issues with pollutants using the Air Quality Index (AQI).
The AQI is used to calculate air quality daily using the five major air pollutants regulated by the Clean Air Act (CAA). As shown in the picture below, different air quality levels are assigned a color to help the public quickly understand when air pollution is reaching unhealthy levels in their communities. To learn more about calculating AQI visit this site.
Indoor Air Pollution
Air pollution can also occur inside a house or building.
Modern building techniques are the main cause of this issue. Newer houses and buildings are well insulated and sealed allowing for very little exchange of inside air with outside air.
Compound this with the fact that chemicals from the manufacturing processes of items such as plastics, carpets, building materials, paints, cleaning products, furniture, etc., can accumulate in the air and become harmful.
This phenomenon where air pollutants inside a house or building accumulate until the point where they are unsafe is known as sick building syndrome. The best strategy for preventing sick building syndrome is the creation of efficient ventilation systems in every home.
Radon is a radioactive gas that is another significant source of indoor pollution.
Any home may have a radon problem, but it is typically found in areas with porous soils overlying rocks that contain uranium. The map below shows which areas in the United States have the highest risk for this type of pollution.
Radon gas can seep into the home and accumulate in a similar manner to air pollutants in sick building syndrome.
Sometimes radon can enter into a household through the water if it is supplied from a well. In very rare cases radon gas can be given off by the building materials of the home itself.
According to the EPA, 1 out of every 15 homes in the United States is estimated to have an elevated level of radon in the air. Radon gas is a concern because it can cause cancer. The EPA has a map Radon Zones.
Smokers who are regularly exposed to radon gas are at a particularly high risk of developing lung cancer. This is known as a synergistic relationship.
Asbestos is a type of mineral fiber that can be found in rocks and soil and is a particulate indoor pollutant. In the past, asbestos was used in a variety of building and construction materials because of its fiber strength and heat resistant properties.
When buildings with this type of material are remodeled or demolished, its fibers can be released into the air. Inhalation of asbestos fibers can cause lung disease.
The three most common health problems caused by exposure to these fibers are lung cancer, mesothelioma, and asbestosis. As in radon, asbestos and smoking have a synergistic relationship, and smokers are at a particularly high risk at developing lung problems when exposed to this substance.
Asbestos can still be found in many products, but it has been banned, particularly in building materials, where there is a threat of it entering into the air. For example, the Clean Air Act (CAA) has banned asbestos from its use in insulation.
Acid Precipitation
This gargoyle, on Notre Dame Cathedral in Paris, has pits and rounded edges, which are the results of acid rain. Acid rain damages statues and architecture in developed nations.
Acid precipitation refers to a mixture of wet and dry deposition that is highly acidic resulting from pollutants from the burning of fossil fuels. When fossil fuels are burned sulfur oxides and nitrogen oxides are released into the atmosphere.
These compounds then come into contact with atmospheric oxygen and water vapor and sulfuric acid and nitric acid are formed.
Acid precipitation can cause corrosion and damage to materials such as metals (such as bronze), paint, and stone (such as marble and limestone).
This can affect the financial and aesthetic value of cars, buildings, bridges, and cultural items (such as monuments, statues, and tombstone).
Ecosystems, particularly aquatic ecosystems, can be greatly affected by acid precipitation.
This type of pollution can kill organisms such as aquatic plants, fish, and other animals. Acid precipitation causes aluminum to leach out of the soil.
The released aluminum accumulates on the gills of fish and causes them to slowly suffocate. Acid shock results when large amounts of acidic water flows into rivers, lakes, or ponds as a result of snow or ice melting in warmer weather and can kill entire populations of fish.
Powdered lime (a base) can sometimes be added to small bodies of fresh water to neutralize its pH in an attempt to offset the effects of the acid precipitation. Unfortunately, often it is not possible to spread enough lime to offset damage done to lakes.
Acid precipitation is hard to control because it is a global problem.
The Helsinki Declaration, enacted in 1985, requires countries to cut sulfur oxide emissions by 30%. Although this was a good idea in theory, the Helsinki Declaration was only signed by 18 nations and the U.S. was not one of them.
The Sophia Protocol, enacted in 1988, required a reduction in nitrogen oxide emissions. The Sophia Protocol was initially signed by 27 nations and the U.S. was not included among the original 27.
The U.S. finally signed the Sophia Protocol in 1989.