Asthma and Air Pollution
Far too many Americans -- about 25 million people -- are intimately acquainted with the symptoms of an asthma attack. When asthma strikes, your airways become constricted and swollen, filling with mucus. Your chest feels tight -- you may cough or wheeze -- and you just can't seem to catch your breath. In severe cases, asthma attacks can be deadly. They kill more than 3,000 people every year in the United States.
Asthma is a chronic, sometimes debilitating condition that has no cure. It keeps kids out of school (for a total of more than 10 million lost school days each year, according to the Centers for Disease Control) and sidelines them from physical activity. Employers lose 14 million work days every year when asthma keeps adults out of the workplace. The disease is also responsible for nearly 2 million emergency room visits a year.
Understanding what might trigger an asthma attack helps asthma sufferers keep their disease in check. Sometimes it's as simple as avoiding dust, tobacco smoke or cockroach droppings. But what if the air outside your home is filled with asthma triggers?
In recent years, scientists have shown that air pollution from cars, factories and power plants is a major cause of asthma attacks. And more than 131 million Americans -- over 40 percent of the nation's population -- live in areas with bad air. Roughly 30 percent of childhood asthma is due to environmental exposures, costing the nation $2 billion per year. Studies also suggest that air pollution may contribute to the development of asthma in previously healthy people. In fact, one recent Los Angeles study found that eight percent of childhood asthma cases are a result of living close (within 250 feet) to major roadways.
Air Pollutants that Trigger Asthma
- Particulate Matter: This term refers to a wide range of pollutants -- including dust, soot, fly ash, diesel exhaust particles, wood smoke and sulfate aerosols -- which are suspended as tiny particles in the air. Some of these fine particles can become lodged in the lungs and could trigger asthma attacks. Studies have shown that the number of hospitalizations for asthma increases when levels of particulate matter in the air rise. Coal-fired power plants, factories, and diesel vehicles are major sources of particulate pollution. Around 44 million people live in areas that fail to meet national air quality standards for particulate matter.
- Ground Level Ozone: A toxic component of smog, ozone triggers asthma attacks and makes existing asthma worse. It may also lead to the development of asthma in children. Ozone is typically produced when pollution from cars and trucks or industrial smokestacks reacts with oxygen and sunlight. Ground level ozone is a serious problem in cities with lots of traffic, such as Los Angeles, Houston and New York City. In 2013, according to the American Lung Association, nearly four in 10 people in the United States (38 percent) lived in areas with unhealthful levels of ozone.
- Sulfur Dioxide (SO2 ): A respiratory irritant associated with the onset of asthma attacks, sulfur dioxide is produced when coal and crude oil are burned. Coal-fired power plants, particularly older plants that burn coal without SO2 pollution controls, are the worst SO2 polluters. 8.1 million Americans lives within 3 miles of a coal-fired power plant. Oil refineries and diesel engines that burn high-sulfur fuel also release large amounts of SO2 into the air.
- Particulate Matter: This term refers to a wide range of pollutants -- dust, soot, fly ash, diesel exhaust particles, wood smoke and sulfate aerosols -- which are suspended as tiny particles in the air. Some of these fine particles can become lodged in the lungs and could trigger asthma attacks. Studies have shown that the number of hospitalizations for asthma increases when levels of particulate matter in the air rise. Coal-fired power plants, factories and diesel vehicles are major sources of particulate pollution. Around 81 million people live in areas that fail to meet national air quality standards for particulate matter.
- Nitrogen Oxide (NOx): A gas emitted from tailpipes and power plants, nitrogen oxide contributes to the formation of ground-level ozone and smog. It also reacts with other air pollutants to form small particles that can cause breathing difficulties, especially in people with asthma. Exposure to high levels of nitrogen dioxide early in life could increase risk of developing asthma.
Watching Out for Bad Air Days
If you have asthma, your doctor can help you design a plan to control and prevent asthma attacks. Limiting your exposure to air pollution can be an important part of that plan. The EPA keeps tabs on local air quality across the country through its daily Air Quality Index, which measures levels of five major air pollutants.
Avoiding Air Pollution Hotspots
Completely avoiding air pollution is impossible, but you can take steps to reduce your family's exposure to air pollution and reduce the health risks. When walking or exercising outdoors, choose a route that avoids major streets or highways where possible. Take your children to playgrounds that are not next to major highways. Further, take any steps you can to ensure that new schools and housing developments are not placed near busy roadways, ports, rail yards or other industrial areas where the risk of diesel exposure increases, and likewise, that new roadways, ports, rail yards, and other industrial areas are not located near schools and homes. If you live in an area with very high air pollution, consider installing air filters inside your home (see pages 42 through 45 of our Clean Cargo guide for more information on Community Mitigation measures).
EPA's Air Quality Index
|Air Quality Index (AQI) Values||Levels of Health Concern||Colors|
|When the AQI is in this range:||...air quality conditions are:||...as symbolized by this color:|
|0 to 50||Good||Green|
|51 to 100||Moderate||Yellow|
|151 to 200||Unhealthy for Sensitive Groups||Orange|
|151 to 200||Unhealthy||Red|
|201 to 300||Very Unhealthy||Purple|
|301 to 500||Hazardous||Maroon|
Check the EPA website or your local television, newspaper or radio weather reports for daily updates on air quality. On bad air days, signified by orange and red colors on the index, children and people with respiratory diseases should limit their time outdoors. Purple and maroon indicate extreme levels of pollution -- even healthy adults should try to stay inside.
Time to Clear the Air
Although air quality has improved in many areas of the country over the past few decades, air pollution still poses a health risk for millions of Americans. Adopting stricter national air quality standards for particulate matter and ozone would help clear the air by giving states a stronger tool to force polluters to clean up. Preserving and strengthening the current regulations for cleaner power plants, cars and trucks will also go a long way towards reducing air pollution. Ultimately, we need to transition away from fossil fuels to a clean economy that replaces dirty diesel, sooty coal and toxic oil with alternative fuels and renewable power.
last revised 1/28/2014
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