Air pollution comes from many different sources. Some sources are identified as being stationary and include: factories, power plants, and smelters. Other sources of pollution are classified as mobile sources and include cars, buses, planes, trucks, lawn mowers, and trains. Natural sources include wildfires, windblown dust, and volcanic eruptions. There are many different sources that create air pollution, but most of what causes it is from human activities. For example, industries, power plants, motor vehicles, agricultural processes, forest fires, and many consumer products are all contributors of air pollution from human beings and can be reduced if enforced.
There are two categories of air pollutants, primary and secondary. Primary pollutants are emitted directly into the atmosphere. This includes such pollutants as carbon dioxide, carbon monoxide, hydrocarbons, and particulates. Secondary pollutants are primary pollutants that, once released into the atmosphere, react with other primary pollutants or atmospheric compounds. The main components that cause air pollution are: suspended particulate matter, sulfur dioxide (SO2), ozone, carbon monoxide (CO), carbon dioxide (CO2), Lead, Chlorofluorocarbons (CFC’s), Hazardous Air Pollutants (HAP’s), Nitrogen Oxide (NOx), and Volatile Organic Compounds (VOC’s). Of these pollutants suspended particular matter, sulfur dioxide, ozone, and lead pose the most widespread and acute risks.
Particulate matter is a mixture of small and large particles of varying chemical composition. Larger particles usually consist of smoke and dust from industrial factories, agriculture, construction, road traffic, plant pollen, and other natural sources. Smaller particles usually come from combustion of fossil fuels. The largest source of fine particles is coal-fired power plants and auto diesel exhaust. Other small particles include soot from vehicle exhaust, fine sulfate, and nitrate aerosols. The health effects of particulates depend on the size of the particle. Small particles, such as those from fossil fuel combustion, are likely to be most dangerous because they can be inhaled deeply into the lungs, settling in areas where the body cannot remove them, causing increased respiratory disease and lung damage.
Sulfur Dioxide (SO2) is an odorless gas at low concentrations, but can have a very strong smell at high concentrations. SO2 is a gas produced by burning coal, mainly in power plants. Some industrial processes, such as production of paper and smelting of metals, produce sulfur dioxide. Sulfur Dioxide is a major contributor to smog and acid rain. It can harm vegetation and metals and can cause lung problems, including breathing problems and permanent damage to lungs.
Ground level ozone is the major component of smog that blankets many urban areas. It is formed when nitrogen oxides from fuel combustion react with volatile organic compounds (VOC’s) such as unburned gasoline or paint solvents in the atmosphere. Breathing ozone can irritate the respiratory tract and impair lung function, causing coughing, shortness of breath, and chest pain.
Lead is a highly toxic metal that produces severe health effects. Lead can cause nervous system damage, digestive problems, and cancer. It has been phased out of gasoline, which has reduced the contamination of air by lead. However, it can still be inhaled or ingested from paint, smelters, manufacture of batteries, fishing lures, ceramic ware, water pipes, and hair dye products.
Two other pollutants, which were mentioned above, that cause serious health effects are Carbon Monoxide (CO) and Carbon Dioxide (CO2). Carbon Monoxide is an odorless, colorless gas. It is produced by the incomplete burning of carbon-based fuels, including gasoline, oil, and wood. After being inhaled, CO molecules can enter the bloodstream, where it spreads throughout the body. Low concentrations can cause dizziness, headaches, and fatigue and high concentrations can be fatal. Carbon Dioxide (CO2) is the principal greenhouse gas, released as a result of human activities (e.g. burning of coal, oil, and natural gas). If someone is exposed to CO2 in solid or liquid form it can cause burns, frostbite, and blindness. If inhaled, it can be toxic in high concentrations, causing an increase in breathing rate, unconsciousness, and death.
Air pollution can affect our health in many ways with both short term and long term effects. Many people are affected by air pollution in different ways. Some individuals are much more sensitive to pollutants than others. Young children and elderly people are prone to 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. Short term effects include irritation to eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia. Other symptoms can include headaches, nausea, and allergic reactions. Long term health effects can include chronic respiratory disease, lung cancer, heart disease, and damage to brain, nerves, liver, or kidneys.
Over the past several decades federal government agencies have been enforcing stricter laws to reduce air pollution. To reduce air pollution in the United States, the Clean Air Act Amendments of 1970 gave the EPA permission to establish air pollution standards and to enforce emission standards for factories and hazardous pollutants. Every state was required to meet ambient air standards by regulating the amount of pollutants from stationary sources, such as power plants and incinerators. Auto manufactures were also authorized to install exhaust controls or develop engines that produce less pollution.
The most important long term solution to air pollution is the elimination of fossil fuels and the replacement of combustion engines. By doing this it will reduce the amount of pollution caused by motor vehicles. Other efforts being made to reduce air pollution are developing alternative energy sources, as well as different kinds of transportation engines, for example buses powered by electricity or steam. Other solutions could be increasing electricity and gasoline rates so that people will reduce the use of them and discourage waste and inefficiency.
