Air Pollution and Your Health

Is Air Pollution Still a Problem?

Almost every major city in America is polluted, and air pollution problems have spread to smaller cities and even to rural areas. The U.S. Environmental Protection Agency (EPA) lists many areas of the nation where air pollution is so bad it exceeds federal health standards.

Polluted air can make healthy people cough and wheeze. For people who are already sick or especially sensitive, air pollution may mean discomfort, limited activities, increased use of medications, more frequent visits to doctors and hospitals, and even a shortened life. And a growing body of scientific studies suggests that aie pollution has long-term effects on the lung's ability to function and on the development of lung disease.

Air pollution comes from power plants, factories, cars, trucks, and buses. It also comes from off-road vehicles such as farm and construction equipment. And from sources in our homes such as paints, consumer products and lawn mowers.

Air pollution costs us billions of dollars every year in health care and lost productivity. So even the fortunate Americans who are not breathing polluted air pay a price for it.

The level of risk posed by air pollution depends on several factors, including the amount of pollution in the air, the amount of air we breathe in a given time and our overall health.

The lung's natural defense system helps to protect against some of the air pollutants we breathe. And people respond differently to pollution. But, no matter where you live, chances are your lungs have been exposed to air pollution.

How Does Air Pollution Hurt the Body?

Our bodies have ways of protecting us from breathing dist, pollen, and germs. Air pollution is an additional stress on the body's defenses.

A sticky substance called mucus lines our air passages. It traps germs and particles before they can enter the lungs. Then cells with tiny, waving hairs called cilia, push the mucus up and out of the body. Air pollution can paralyze or even destroy the cilia. That allows dirt and germs to build up in the mucus, leaving our bodies more vulnerable to disease.

Our bodies also defend themselves against pollution by trying to breathe less. Air passages tighten temporarily and breathing becomes harder.

Smoking also harms the body's defenses, making the body more vulnerable to pollution and disease. It can make the effects of air pollution much worse.

What Are the Problem Pollutants and Their Health Effects?

Exposure to air pollution can make your eyes water, irritate your nose, mouth and throat, and make you cough and sneeze. But more important, it can also worsen and may cause lung diseases like asthma, bronchitis and emphysema. In some cases, it can even contribute to the premature death of people with heart and lung disease.

The U.S. Environmental Protection Agence has developed health-based national air quality standards for siz pollutants. They are:

Carbon monoxide (CO) is an odorless, colorless, poisonous gas that comes mainly from motor vehicles and other combustion exhaust.
     Health effects: Carbon monoxide interferes with the blood's ability to carry oxygen to the brain, heart and other tissues, and it is particularly dangerous for people with existing heart disease, and unborn or newborn children.

Ozone (O₃) is the major harmful ingredient in smog. It is not emitted directly into the air but produced in the atmosphere when gases or vapors of organic chemicals called hydrocarbons combine with nitrogen oxide compounds in the presence of sunlight. Organic hydrocarbon gases, one of the raw ingredients of ozone, are released from a variety of sources related to human activities. Major sources include refineries, gas stations, motor vehicles, chemical plants, paints and solvents. Harmful ozone in the lower atmosphere should not be comfused with ozone in the upper atmosphere, which protects us from ultraviolet radiation.
     Health effects: Ozone reacts with lung tissue. It can inflame and cause harmful changes in breathing passages, decrease the lungs' working ability and cause both coughing and chest pains. Ozone air pollution, found at unhealthful levels in nearly all of the nation's major urban areas, may particularly affect millions of otherwise healthy Americans who, for currently unkown reasons, are especially sensitive to it.
People who exercise are also more vulnerable to the effects of ozone, suffering symptoms and a reduced ability to breathe at relatively low ozone levels. Ozone pollution -- even at low levels -- has also been linked to hospital admissions and emergency room visits for respiratory problems.

Nitrogen dioxide (NO₂) and related nitrogen oxides (Nox) are produced when fuel is burned, especially in power plants and motor vehicles. These oxides of nitrogen compunds contribute to ozone formation, and are a health problem themselves. NO₂ also changes in the atmosphere to form acidic particles and liquid nitric acid.
     Health effects: Both NO₂ and Nox may threaten human health. Nitrogen dioxide seems to act on the body like both ozone (see above) and sulfur dioxide (see below).

Sulfur dioxide (SO₂) is created when sulfur-containing fuel is burned, primarily in power plants and diesel engines. Like NO₂, it can also change in the atmosphere into acidic particles and into sulfuric acid.
     Health effects: Sulfur dioxide constricts air passages, making it a problem for people with asthma and for young children whose small lungs need to work harder than adult lungs. Even brief exposure to relatively low levels of sulfur dioxide can cause an asthma attack.

Particulate matter (PM) includes microscopic particles and tiny droplets of liquid. These particles come from the burning of fuels by industry and diesel vehicles and from earth-moving activities such as construction and mining.
     Health effects: Larger particles can be stopped in the nose and upper lungs by the body's natural defenses. The smallest particles escape the body's defenses and go deep into the lungs, where they may become trapped. Exposure to particulate pollution can cause wheezing and other symptoms in people with asthma or sensitive airqays. Particulate pollution has been linked to hospital admissions and emergency room visits for respiratory problems and to a substantial increase in prematur death.

Lead (Pb) has been known as a poinsonous substance for many years. Due to past major reductions and now the elimination of lead in gasoline, there has been a significant drop in public exposure to lead in outdoor air. Remaining air pollution sources include lead smelters, incineration of lead batteries, and burning lead-contaminated waste oil. Howeer, the most common sources of current lead exposure are indoors from old lead-containing paint and soil.
     Health effects: Exposure to high levels of lead can damage the blood, brain, nerves, kidneys, reproductive organ, and the immune system. Lower levels that are more commonly associated with current exposires can result in impaired mental functioning and development in children and raising blood pressure in middle-aged men. Lead accumulates in the body, so repeated small doses can be harmful.

Toxic air pollution In addition to these six pollutants for which qir quality standards have been set, toxic air pollution, also referred to as hazardous air pollution, consists of those substances in the air which are known or suspected to cause cancer, genetic mutation, birth defects or other serious illnesses in people even at relatively low exposure levels. Toxic and cancer-causing chemicals can be inhaled directly or carried by small particles into the lungs. Millions of pounds of these chemicals are emitted into the air ocer our nation every year by motor vehicles and by both large and small industry. Exposure to these toxic contaminants is regulated nationally by requiring the use of pollution controls on these sources, rather than by air quality standards. Your local <%$alatitle%> has more information on these toxic pollutants.

What Are the Problem Pollutants and Their Health Effects?

Air pollution's harm has been documented in all three kinds of studies. Air pollution can kill, especially when several kinds of pollution work together. In London, a "killer fog" in 1952, polluted with sulfur and particles, took an estimated 4,000 lives. People with lung and heart diseases were particularly vulnerable.

Closer to home, a Harvard University study estimated that about five percent of deaths in the typical polluted American city each year are linked to acidic particles in the air. Another study of particulate pollution estimates that tens of thousands of premature deaths each year can be attributed to this type of air pollution.

Pollution can be a serious problem even at relatively low levels. These levels of smog and particulate pollution have been linked to increases in emergency room visits by asthma victims and others with lung problems. Studies of children and people with asthma have related coughing, wheezing and other signs of lung distress to pollution levels below current federal standards. The <%$alatitle%> believes that several of the current federal air quality standards such as those for ozone and particulates need to be strengthened to protect public health.

How Can You Protect Yourself Against Air Pollution?

What Can You Do About Air Pollution?