With the population in the world increasing dramatically it makes clean air more difficult to find. The United States noticed back in 1970 that we were going to have a problem with pollution. This caused the US Congress to pass the Clean Air Act and amend it in 1977 and again in 1990. Scientists have found that there are eight main air pollutants, sulfur dioxide, particulates, carbon monoxide, ozone, nitrogen dioxide, lead, carbon dioxide, and hydrocarbons. These air pollutants can cause other problems such as photochemical smog, temperature inversions, and the two most harmful acid deposition and acid rain.
Sulfur dioxide is one source of air pollution. This is a yellowish brown gas that forms when fuel, coal, and oil are burned. One major problem of sulfur dioxide is that is dissolves in water vapor to form acid. It interacts with other gases and particles in the air to form chemicals that can not only be harmful to humans, but the environment that surrounds them. Sulfur dioxide not only aggravates symptoms of heart and lung disease, but it also obstructs breathing passages and increases your risk of common colds, asthma, and emphysema. It is also very harmful to the world around us. It is very toxic to the plants that provide us with our air we breath. Sulfur dioxide destroys paintings, metals, and decreases visibility. Many improvements have been made to decrease sulfur dioxide, but the biggest improvement happened in 2007 when a new ultra-low sulfur diesel became available in the United States.
Tiny solid particles suspended in the air are known as particulates, another form of air pollution. These particles are caused by industrial processes and combustion engines. They irritate humans by carrying heavy metals and carcinogenic agents deep into the lungs. But scientists have found that there are starting to be less particulates in the air today.
Another source of air pollution is carbon monoxide. The main cause for this pollutant is car emissions. Carbon monoxide is an odorless, colorless gas that doesn’t allow the blood to absorb and carry oxygen through the body. It causes you to think slowly, it slows your reflexes down, and causes you to become drowse. Carbon monoxide poisoning is the third leading cause of unintentional poisoning in the United States, killing around fourteen thousand people a year.
Coal powered boilers and motor vehicles release nitrogen dioxide into the atmosphere. This pollutant is recognizable by its amber color gas. It causes common colds, the flu, and pneumonia. Also it harms our plant life. You may have seen this before on plants, it causes brown discoloration on them. When nitrogen and sulfur dioxide combine they cause acid deposition.
Ozone, something we can’t live with or without. It is form of oxygen that is created when nitrogen dioxide reacts with sunlight and oxygen molecules. Ground-level ozone causes humans to cough and choke. It can also cause pneumonia and aggravate heart disease. But we as humans can’t live without ozone because it serves as a protective shield against heat and radiation from the sun.
A pollutant that has been found that has been found in paint, batteries, pipes, dirt, and has been found in candies from Mexico. Lead is a very dangerous; it harms the circulatory, reproductive, urinary, and nervous system. The main harm is it causes birth defects. Lead is still a major problem; in August 2007 there was a recall of over 2 million Mattel toys manufactured in China that had been found to have excessive levels of lead in their paint. It also is a problem in the US, with 25 percent of US homes still has lead based paint in them. US scientists also found that about 325,000 children have an unsafe blood lead levels. So lead is still a problem that we have to take care of.
The United States not only has a problem with lead, but we also are the largest carbon dioxide emitter in the world. The US accounts for almost one quarter of the total emissions in the world. Carbon Dioxide comes from the emissions form vehicles. It helps form greenhouse gases which cause global warming. Carbon dioxide is the most plentiful gas, but it is essential to all life because it is the primary fuel for plant respiration. But lately there has been so much carbon dioxide that there isn’t enough plants to use it all up. This means that the leftover gas has to go somewhere; this is what causes the global warming.
Most automobile engines emit hundreds of different hydrocarbons into the atmosphere around us. By themselves they cause very few if any problems, but when they combine with sunlight and pollutants is when they cause problems. When combined these pollutants are known as VOCs. They form poisons such as formaldehyde, ketones, and peroxyactyl nitrate. All these poisons affect your respiratory system. Another major problem of hydrocarbons is that they are a major part of forming smog.
Photochemical smog or ozone pollutants, is a brown hazy mix of particulates and gases that form when oxygen containing nitrogen and hydrocarbons react in sunlight. Smog is known to form in places that have temperature inversions. This is a weather condition when a cool layer of air is trapped under a layer of warm air. Temperature inversion is most likely to happen in valley regions blocked by hills and mountains. Smog makes it very difficult to breath, also can cause your eyes to burn, headaches, and even make you feel nausea.
Another big problem caused by these eight pollutions is acid deposition and acid rain. Acid deposition is a process that occurs when rain, sleet, and snow hold acid particles in them. It means the same as acid rain, but acid rain is considered the precipitation that has fallen to the ground. These pollutants can be set down in a couple different ways. In northern hemispheres pollutants are deposited by rain and snow, this is known as wet deposition. Dry deposition is most common in Europe. This is when gases and particles are deposited directly onto land. The last deposition is cloud deposition, where clouds provide a significant input of acid pollutions over high ground. No matter how the acid is deposited it causes many problems. One main problem is leaching, this is when the acids cause metal to dissolve and also could filter through the soil and get into the ground water.
All these examples of pollutants are all bad, but will never completely go away with humans alive. But lately the world pollution has been getting a lot better. People are starting to become aware of what they are doing to our one and only environment. We’ll never be able to completely stop pollution, but we can use fewer pollutants and slow down the depletion of our environment.

Work Cited http://www.lbl.gov/ http://healthandenergy.com
Health the Basics, Health Book, Chapter 15