The air we breathe in many U.S. cities is being polluted by activities such as driving cars and trucks; burning coal, oil, and other fossil fuels; and manufacturing chemicals. Air pollution can even come from smaller, everyday activities such as dry cleaning, filling your car with gas, and degreasing and painting operations. These activities add gases and particles to the air we breathe. When these gases and particles accumulate in the air in high enough concentrations, they can harm us and our environment. More people in cities and surrounding counties means more cars, trucks, industrial and commercial operations, and generally means more pollution.
Air pollution is a problem for all of us. The average adult breathes over 3,000 gallons of air every day. Children breathe even more air per pound of body weight and are more susceptible to air pollution. Many air pollutants, such as those that form urban smog and toxic compounds, remain in the environment for long periods of time and are carried by the winds hundreds of miles from their origin. Millions of people live in areas where urban smog, very small particles, and toxic pollutants pose serious health concerns. People exposed to high enough levels of certain air pollutants may experience burning in their eyes, an irritated throat, or breathing difficulties. Long-term exposure to air pollution can cause cancer and long-term damage to the immune, neurological, reproductive, and respiratory systems. In extreme cases, it can even cause death.
Listed below are issues affecting air quality, our health, and the environment. To find out more about the issues, visit the links provided.
Acid Rain"Acid rain" is a broad term describing acid rain, snow, fog, and particles. It is caused by sulfur dioxide and nitrogen oxides released by power plants, vehicles, and other sources. Acid rain harms plants, animals, and fish, and erodes bulding surfaces and national monuments. In addition, acidic particles can hurt people's lungs and reduce how far we can see through the air.
Air Quality IndexThe AQI is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health.Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health in this country.
- AirNow - Air quality conditions and forecasts
- Air Quality Index - A Guide to Air Quality and Your Health
Climate change refers to any significant change in measures of climate (such as temperature, precipitation or wind) lasting for an extended period (decades or longer). For full definitions of "climate change" and "global warming," see the Basic Information page on our Climate Change Website.
Haze and VisibilityHaze is caused when sunlight encounters tiny pollution particles in the air. It degrades visibility in many American cities and affects some of our nation's most treasured areas, including Grand Canyon, Yellowstone, Acadia, and Shenandoah.
Indoor Air QualityIndoor air levels of many pollutants may be 2-5 times, and occasionally, more than 100 times higher than outdoor levels. Indoor air pollutants are of particular concern because most people spend as much as 90% of their time indoors. Common sources can include burning kerosene, wood or oil, smoking tobacco products, releases from household cleaners, pesticides, building materials, and radon.
- Asthma and Indoor Environments
- Asthma Facts
- Second Hand Smoke
- Indoor Air Quality FAQs
- Radon Publications
Ozone DepletionA protective ozone layer is located in the stratosphere about 22 miles above the Earth's surface. This layer protects us from the sun's harmful ultraviolet radiation. This protective shield is being damaged by chemicals such as CFCs, halons, and methyl chloroform, and can lead to harmful health effects such as skin cancer and cataracts.
RadiationRadiation occurs naturally (e.g. radon) but we also use radioactive materials to generate electricity and to diagnose and treat medical problems. Frequent exposures to radiation can cause cancer and other adverse health effects.
Smog, Particles, and Other Common PollutantsBreathing air pollution such as ozone (a primary ingredient in urban smog), particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, and lead can have numerous effects on human health, including respiratory problems, hospitalization for heart or lung disease, and even premature death. Some can also have effects on aquatic life, vegetation, and animals.
Toxic Air PollutantsIncludes 188 hazardous air pollutants, such as benzene, methylene chloride, mercury, and dioxins. Some are known or suspected to cause cancer. Others may cause respiratory effects, birth defects, and reproductive and other serious health effects. Some can even cause death or serious injury if accidentally released in large amounts.
Vehicles and EnginesCars, buses, trucks, planes, trains, boats, and other sources contribute to air pollution.