Seven Major Pollutants

Exposure to pollutants can cause adverse health effects like respiratory problems, heart and lung disease and even premature death, so it is important to limit pollutants in our environment as much as possible. To preserve our health, organizations such as the Environmental Protection Agency, EPA, regulate major pollutants in the air, soil and waterways.

Lead

• Do you remember when you could select "regular" or "unleaded" gasoline? In those days, automobiles were one of the worst contributors to airborne lead. Today, that has changed, but lead emissions still exist in the air from industry and leaded airplane gasoline.

  Environmental lead is most commonly found in the interior or exterior paint of houses built before 1978, in dust from deteriorating paint, and in contaminated soil. It can also be found in drinking water, especially if lead pipes are present. A deadly toxin, lead can cause brain damage or even premature death. There are often few symptoms of lead poisoning until it is too late, and children under six are the most frequently affected.

Carbon Monoxide

• Colorless and odorless, carbon monoxide (CO) is a gas discharged during combustion. It is present more often in the air of urban areas where more vehicles are producing a larger amount of emissions. Because it reduces your blood's ability to carry oxygen throughout your body, CO can be extremely harmful. People who have existing heart conditions are especially susceptible to CO-related problems, but in high concentrations, anyone can be affected by, and even die from carbon monoxide poisoning. Homes with natural gas are generally required to have carbon monoxide detectors installed to prevent the inhabitants from being affected by this deadly gas.

Ozone

• Ozone, a gas comprised of three oxygen molecules, is one of the main elements of smog. Unlike some pollutants, ozone is not directly emitted but rather, is created when sunlight hits a mixture of volatile organic compounds (VOCs) and oxides of nitrogen, causing a chemical reaction. Car exhaust, chemical solvents and industrial emissions are some of the main sources of the components that mix to form ozone.

  Ozone can trigger chest pain, throat irritation and problems with breathing, and repeated exposure can actually cause lung scarring. Ozone also damages crops, and is responsible for a $500 million loss in crops each year in the U.S.

Particulate Matter

• A mixture of very small particles and droplets of liquid, particulate matter -- also called particle pollution or PM -- is comprised of acids, metals, chemicals and dust or soil bits. The smaller the piece of particulate matter, the bigger the problem because smaller particulates can more easily pass through the nose or mouth and be inhaled into the lungs.

  Particulate matter includes inhalable coarse particles, which are found near dusty industrial plants and roadways; and fine particles, which are found in haze and smoke after being emitted from fires, power plants or cars. Particulate pollution can cause damage to the hearts and lungs of people exposed to it, especially to those who have existing heart or lung conditions.

Sulfur Dioxide

• Primarily emitted from power plants and other industrial entities, sulfur dioxide is an extremely reactive gas that can be very dangerous even with short or limited exposure. Short-term exposure of as little as 5 minutes can produce adverse effects like difficulty breathing and can worsen asthma symptoms. Short-term exposure of between 5 minutes and 24 hours has also been linked to an increase in ER visits or inpatient admissions, especially for the most at-risk populations -- the elderly, newborns and the immunocompromised.

Nitrogen Dioxide

• Another very reactive gas, nitrogen dioxide is formed from the emissions of automobiles, industrial power plants and heavy off-road equipment. Nitrogen contributes to the development of both ground-level ozone and fine particulate matter, and thus is a particularly dangerous environmental pollutant. Even being exposed to nitrogen dioxide for a short time, 30 minutes to 24 hours, can cause symptoms like airway inflammation and other respiratory issues.

Dirt

• Believe it or not, the EPA reports that dirt is the number one pollutant of our rivers and streams. When excessive trees, shrubs and other vegetation are removed from an area, the dirt is left unprotected and washes into streams and rivers during rains. The dirt then blocks sunlight, preventing photosynthesis and causing water plants to die off; clogs the gills of freshwater fish and even kills off fish eggs. To address the dirt problem, the EPA advocates different approaches to farming and development that leave less soil exposed.