Air Pollution

What is Air Pollution?

In the earth, Air is the ocean we breath. Air contains oxygen which is essential for our bodies to live. Air is 99.9% nitrogen,oxygen, water vapor and inert gases. Developing world can release substances into the air, some of which can cause problems for humans, plants and animals.There are several main types of pollution and well-known effects of pollution which are commonly discussed. These include smog, acid rain, the greenhouse effect, and "holes" in the ozone layer. Each of these problems has serious implications for our health and well-being as well as for the whole environment.

1. One type of air pollution is the release of particles into the air from burning fuel for energy. Diesel smoke is a good example of this particulate matter . The particles are very small pieces of matter measuring about 2.5 microns or about .0001 inches. This type of pollution is sometimes referred to as black carbon pollution. The exhaust from burning fuels in automobiles, homes, and industries is a major source of pollution in the air. Some authorities believe that even the burning of wood and charcoal in fireplaces and barbeques can release significant quanitites of soot into the air.

2. Another type of pollution is the release of noxious gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides, and chemical vapors. These can take part in further chemical reactions once they are in the atmosphere, forming smohs and acid rain.
Pollution also needs to be considered inside our homes, offices, and schools. Some of these pollutants can be created by indoor activities such as smoking and cooking. In the United States, we spend about 80-90% of our time inside buildings, and so our exposure to harmful indoor pollutants can be serious. It is therefore important to consider both indoor and outdoor air pollution.

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Carbonmonoxide
- The largest source of anthropogenic (result from human activity) CO is the incomplete combustion of fossil fuel
- Not enough oxygen availale to the fuel = incomlete combustion occurs

2C8H18(l) + 17O2(g) à 16CO(g) + 18H2O(l)

- To reduce level of anthropogenic CO, most cars and some buses, trains and industiral machnery are equipped with catalytic converters
- Catalytic converters work to convert the toxic by products of combustion, CO included, to less toxic substances

2CO(g) + O2(g) à 2CO2(g)

Oxides of nitrogen (NOx)
- is the general term used to classify nitrogen oxides (NO & NO2)
- nitrogen oxides are formed at high temperatures inside internal combustion engines when the nitrogen in the air combines
N2(g) + O2(g) à 2NO(g)
- in area with large traffic volume, the abundance of NO results in the formation of a red haze, smog

- To reduce the amount of NOx pollutants in the atmosphere one can make use of the catalytic converter, which is also useful for the lowering the level of CO.
In the catalytic converter the harmful NO is reduced to diatomic nitrogen at the same time as CO is being oxidized to carbon dioxide,

2CO(g) + 2NO(g) à 2CO2(g) + N2(g)

How can air pollution hurt my health?

Air pollution can affect our health in many ways with both short-term and long-term effects. Different groups of individuals are affected by air pollution in different ways. Some individuals are much more sensitive to pollutants than are others. Young children and elderly people often suffer more from the effects of air pollution. People with health problems such as asthma, heart and lung disease may also suffer more when the air is polluted. The extent to which an individual is harmed by air pollution usually depends on the total exposure to the damaging chemicals, i.e., the duration of exposure and the concentration of the chemicals must be taken into account.

- Examples of short-term effects include irritation to the eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia. Other symptoms can include headaches, nausea, and allergic reactions. Short-term air pollution can aggravate the medical conditions of individuals with asthma and emphysema. In the great "Smog Disaster" in London in 1952, four thousand people died in a few days due to the high concentrations of pollution.
- Long-term health effects can include chronic respiratory disease, lung cancer, heart disease, and even damage to the brain, nerves, liver, or kidneys. Continual exposure to air pollution affects the lungs of growing children and may aggravate or complicate medical conditions in the elderly. It is estimated that half a million people die prematurely every year in the United States as a result of smoking cigarettes.
Research into the health effects of air pollution is ongoing. Medical conditions arising from air pollution can be very expensive. Healthcare costs, lost productivity in the workplace, and human welfare impacts cost billions of dollars each year.

- when there are high levels of NOx can be very harmful to people with lung diseases. ex) asthma
- cause damage to healthy lung tissue and reduction in lung fuction

Outdoor Air Pollution

- is a type of large-scale outdoor pollution. It is caused by chemical reactions between pollutants derived from different sources, primarily automobile exhaust and industrial emissions. Cities are often centers of these types of activities, and many suffer from the effects of smog, especially during the warm months of the year. For each city, the exact causes of pollution may be different. Depending on the geographical location, temperature, wind and weather factors, pollution is dispersed differently. However, sometimes this does not happen and the pollution can build up to dangerous levels.

- A temperature inversion occurs when air close to the earth is cooler than the air above it. Under these conditions the pollution cannot rise and be dispersed. Cities surrounded by mountains also experience trapping of pollution. Inversion can happen in any season. Winter inversions are likely to cause particulate and cabon monoxide pollution. Summer inversions are more likely to create smog.

- Another consequence of outdoor air pollution is . When a pollutant, such as sulfuric acid combines with droplets of water in the air, the water (or snow) can become acidified . The effects of acid rain on the environment can be very serious. It damages plants by destroying their leaves, it poisons the soil, and it changes the chemistry of lakes and streams. Damage due to acid rain kills trees and harms animals, fish, and other wildlife.

The Greenhouse Effect, also referred to as global warming, is generally believed to come from the build up of carbon dioxide gas in the atmosphere. Carbon dioxide is produced when fuels are burned. Plants convert carbon dioxide back to oxygen, but the release of carbon dioxide from human activities is higher than the world's plants can process. The situation is made worse since many of the earth's forests are being removed, and plant life is being damaged by acid rain. Thus, the amount of carbon dioxide in the air is continuing to increase. This buildup acts like a blanket and traps heat close to the surface of our earth.

Ozone depletion is another result of pollution. Chemicals released by our activities affect the stratosphere , one of the atmospheric layers surrounding earth. The ozone layer in the stratosphere protects the earth from harmful ultraviolet radiation from the sun. Release of chlorofluorocarbons (CFC's) from aerosol cans, cooling systems and refrigerator equipment removes some of the ozone, causing "holes"; to open up in this layer and allowing the radiation to reach the earth. Ultraviolet radiation is known to cause skin cancer and has damaging effects on plants and wildlife.

Indoor Air Pollution

Many people spend large portion of time indoors - as much as 80-90% of their lives. We work, study, eat, drink and sleep in enclosed environments where air circulation may be restricted. For these reasons, some experts feel that more people suffer from the effects of indoor air pollution than outdoor pollution. There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints, furniture, etc. cause pollution inside buildings.

Indoor Air Pollution
Indoor Air Pollution

Reason for indoor air quality problems.
Household products and personal care items are a constant source of indoor air pollution. Hobbies such as welding and soldering can easily add more pollutants to indoor environments. Office machines and domestic air cleaners are a major source of ozone.


How can we prevent the damaging effects of air pollution?

- In many countries in the world, steps are being taken to stop the damage to our environment from air pollution. Scientific groups study the damaging effects on plant, animal and human life. Legislative bodies write laws to control emissions. Educators in schools and universities teach students, beginning at very young ages, about the effects of air pollution.
The first step to solving air pollution is assessment . Researchers have investigated outdoor air pollution and have developed standards for measuring the type and amount of some serious air pollutants.

- Scientists must then determine how much exposure to pollutants is harmful.
Once exposure levels have been set, steps can be undertaken to reduce exposure to air pollution. These can be accomplished by regulation of man-made pollution through legislation. Many countries have set controls on pollution emissions for transportation vehicles and industry. This is usually done to through a variety of coordinating agencies which monitor the air and the environment.

- by driving a car that gets at least 35 miles a gallon, walking, bicycling, and using mass transit when possible. Replace incandescent light bulbs with compact fluorescent bulbs, make your home more energy efficient, and buy only energy efficient appliances.

Reference

http://www.pollutionissues.com/Ho-Li/Indoor-Air-Pollution.html
http://healthandenergy.com/air_pollution_causes.htm
http://europa.eu/legislation_summaries/environment/air_pollution/index_en.htm
http://www.lbl.gov/Education/ELSI/pollution-main.html
http://classes.colgate.edu/core114/legislation/ecopain/copy/air.htm