Asbestos is an insulating material commonly used from the
1950s to 1970s for soundproofing and to cover floors and ceilings, water pipes,
and heating ducts. When it becomes crumbly or frayed, asbestos fibers can be released
into the air. Breathing asbestos fibers may cause
lung cancer, asbestosis (scarring of the lung tissue), or
Radon is a colorless, odorless radioactive gas that can
enter your home through cracks in concrete walls and floors and through floor
drains. The most common source of radon is uranium that normally exists in the
soil or rock on which homes are built. Problems show up when the concentration of
radon builds up in a home or building. Both old or new homes can have problems
with radon even if they don't have a basement.
Exposure to radon
gas is the second leading cause of lung cancer. (Tobacco smoke is the leading
cause.) The risk of
radon-associated lung cancer is
much higher for smokers than nonsmokers.7
You cannot smell or see radon. But it's
easy to test for it with a do-it-yourself kit available in hardware stores or
through the U.S. Environmental Protection Agency (EPA). For more information,
see the topic
Treatment for indoor air pollution
How you react to indoor air pollutants
depends on your age, health, and how sensitive you are to certain chemicals or
biological pollutants, such as bacteria or molds. Treatment can be as simple as removing
and limiting your exposure to
toxic chemicals in your home. In some cases, serious
illnesses—such as cancer, heart disease, and respiratory disease—can develop
after long-term and repeated exposures. With such long-term exposures,
treatment may be extensive, depending on the type of illness.
Outdoor air pollution
Polluted air comes from many
sources, such as factories, cars, buses, trucks, and power plants. And there
are other sources that you may not think of, such as dry cleaners, wildfires,
and dust. Dirty air is a threat to your health. And it also damages crops,
trees, water, and animals.
There are at least six major components of air
- Ozone. Ozone is a gas
that exists at ground level as well as miles above the earth. It's made by a
chemical reaction between nitrogen oxides and
volatile organic compounds (VOCs) in the presence of
heat and sunlight. "Good" ozone occurs naturally about 10 to 30 miles above the
earth's surface. There, in the stratosphere, it forms a layer that protects the earth's surface from
the sun's harmful rays. At ground level, "bad" ozone (smog) exists. Exhaust
from vehicles, industrial emissions, gasoline vapors, and chemical solvents are
major sources of nitrogen oxides and VOCs. Add sunlight and hot weather to the
mix, and harmful concentrations of ozone may develop. Because of the heat
factor, ground-level ozone is a summertime air pollutant that can be dangerous,
especially for people with respiratory illnesses. Problems include:
Particulates include dust, dirt, soot, smoke, and liquid droplets found in the
air. They come from many sources, such as vehicles, factories, construction
sites, unpaved roads, and burning wood. Other particulates are formed when
gases from burning fuels react with water vapor and sunlight. This can result
from the combustion of fuels in motor vehicles and from industrial and power
plants. Very small particulates that can get into your lungs are especially harmful to your health and may increase your risk of lung cancer and heart problems.8, 9 Particulates in the air you breathe can cause:
- Asthma attacks.
and difficult or painful breathing.
- Reduced lung function.
- Eye, nose, and
- Carbon monoxide. In
cities with lots of traffic, most of the carbon monoxide put into the air
comes from vehicle exhaust. It also comes from manufacturing processes, wood
burning, and forest fires. Indoor sources include cigarettes and space heaters.
Carbon monoxide reduces the body's ability to deliver
oxygen to tissues and organs, such as the heart and brain. It is especially
dangerous for people who have heart problems. Carbon monoxide can be fatal to
those exposed to extremely high levels. Every year
carbon monoxide poisoning is a leading cause of
deaths from toxic chemicals. People with carbon monoxide poisoning may have:
- Nitrogen dioxide. When
mixed with other particles in the air, nitrogen dioxide can often be seen as a
reddish brown layer over many urban areas. Sources are fuels burned by
vehicles, electric utilities, and industrial plants. Nitrogen dioxide is one of
the nitrogen oxides, a group of highly reactive gases that contain various
amounts of nitrogen and oxygen. Studies show that nitrogen dioxide may increase your risk of heart problems, such as heart failure.9 Nitrogen oxides cause many problems,
- Breathing problems.
- Acid rain, which is made when nitrogen
oxides and sulfur dioxide react with other substances in the air and form
acids. The acids then fall to earth as rain, snow, dry particles, or fog.
- Toxic chemicals. Nitrogen oxides mix with common organic chemicals
and even ozone to create toxic chemicals that can cause biological
- Visibility impairment. Nitrogen dioxide and nitrate
particles block light transmission and reduce visibility in urban areas.
- Sulfur dioxide. This gas is formed when fuels containing sulfur are burned. Examples are when coal and
oil burn, when gasoline is extracted from oil, or when metals are
extracted from ore. Sulfur dioxide is
put into the air when fossil fuel is burned, such as by coal-fired power plants.
Other sources are industries that create products from metallic ore, coal, and
crude oil or those that burn coal or oil, such as petroleum refineries or metal
processing facilities. Sulfur dioxide causes:
- Health problems for people with asthma
and heart conditions.
- Acid rain.
- Damage to forests and
- Damage to fish in streams and lakes.
- Lead. Leaded gasoline
used to be the main source of lead in the air. But because leaded fuels have
been phased out, the main sources of lead emissions are metals-processing
facilities, especially lead smelters. Lead may cause serious health problems,
- Damage to kidneys, liver, brain, nerves,
and other organs. Lead may also cause
osteoporosis and reproductive problems. Excessive
exposure can cause seizures, intellectual disability, behavioral disorders, memory problems, and mood
changes. Low levels of lead cause brain and nerve damage in young children and
fetuses, which can lead to learning problems and low IQ.
- High blood pressure and increases in heart disease.
For more information, see the topics
Carbon Monoxide Poisoning and