Air Pollutants

Nitrogen Oxides:

Automobile emissions and emissions from coal burning power plants are the primary sources of nitrogen oxides in the atmosphere. In the home, gas stoves, the burning of wood, and tobacco smoke all contribute to elevated levels of nitrogen oxides. At low levels of exposure, nitrogen oxides can irritate the eyes, nose, throat, and lungs, and may cause coughing, shortness of breath, and nausea. High levels of exposure can seriously damage tissues in the throat and upper respiratory tract and trigger the build-up of fluid in the lungs. Additionally, nitrogen oxides also contribute to acid rain and can react with other pollutants to form ozone and particulate matter.

Ozone:

In the upper layer of the earth's atmosphere (the stratosphere), ozone occurs naturally and helps to protect us from the sun's harmful ultraviolet (UV) rays. But in the lower atmosphere (the troposphere), ozone is the most pervasive outdoor air pollutant in the United States. Harmful ground-level ozone is the major component of smog and it is formed when pollutants released by cars, power plants, and other sources react with sunlight. Exposure to elevated ozone levels can irritate the lungs and cause severe coughing, shortness of breath, and pain when breathing. Ozone exposure also can trigger asthma attacks, aggravate chronic lung diseases like emphysema and bronchitis, increase the body's susceptibility to respiratory infections, and cause permanent damage to the lining of the lung.  Click here to read PSR's Code Red Alert: Ozone and Your Health.

Particulate Matter:

Particulate matter, also known as particle pollution, is made up of a mixture of solid particles and liquid droplets suspended in the air. While some particles such as dust and soot are large enough to be seen with the naked eye, others are so tiny that they can only be viewed with the aid of a microscope. Produced primarily by the combustion of fossil fuels by cars, power plants, and industry, particulate matter is one of the nation's deadliest air pollutants. Each year, particle pollution causes an estimated 60,000 premature deaths. Exposure to particulate matter also exacerbates respiratory and cardiovascular diseases and can cause heart attacks, strokes, asthma attacks, and lung cancer. Fine particles are especially dangerous because they can bypass the body's natural defenses to lodge deep in the lungs where they can pass easily into the bloodstream.

Sulfur Dioxide:

Sulfur dioxide is released to the atmosphere mainly by the burning of coal and oil and by industrial processes such as the smelting of metallic ores. Sulfur dioxide also is produced in nature by processes such as decomposition and volcanic eruptions, but human activities are the primary contributor to SO2 pollution. Electric utilities alone account for nearly two-thirds of annual sulfur dioxide emissions. At high exposure levels, sulfur dioxide can cause temporary breathing difficulty for people with asthma and long-term exposure to high levels of SO2 can cause respiratory illness and aggravate cardiovascular diseases.  Sulfur dioxide also reacts with nitrogen oxides and other air pollutants to form particle pollution and acid rain, which damages forest and aquatic ecosystems.

Volatile Organic Compounds (VOCs):

VOCs are organic compounds (meaning they contain carbon)that easily form vapors at room temperature. In outdoor air, VOCs are generated primarily by power plants, automobiles, and industry. Indoors, VOCs are emitted by a number of household items, such as paint, paint thinner, cleaning supplies, glue, and markers. Short-term exposure to VOCs can irritate the respiratory tract and eyes and cause dizziness and headaches. Long-term exposure is linked to cancer and a number of adverse neurological, reproductive, and developmental effects. VOCs can also impact health by combining with nitrogen oxides to form ozone.