Asthma, Traffic and Air Pollution

Asthma is the nation's fastest-growing chronic disease, afflicting more than 22 million Americans. Asthma rates among children under age four more than doubled over the last twenty years. Particularly hard-hit are communities of color. A recent study revealed that one-quarter of children in New York City's Harlem have asthma.

Diesel emissions have been associated with asthma and its symptoms. In traffic-choked New York City, asthma statistics are staggering. New York City's children were twice as likely to be hospitalized for asthma as the average American child. (More on rising rates of disease and traffic in New York and elsewhere). 

For asthma, genetics loads the gun, but environment pulls the trigger. Once a person develops asthma, factors like dirty air can trigger an attack. Cutting traffic congestion and air pollution is one way to lessen the impact of asthma and other respiratory diseases. (For answers to common questions about traffic and health, read a Q&A with Dr. John Balbus, our chief health scientist.)

What is asthma, and who Gets It?

• Asthma is a serious chronic lung disease that inflames and constricts the airways, causing attacks of wheezing and gasping in those afflicted.
• Children (because of their body size and developing lungs) and the elderly are the most vulnerable to pollutants that trigger asthma attacks.
• Most people who develop asthma likely have a genetic predisposition to get the disease and experience critical environmental exposures during their first years of life.

What is the connection between asthma and dirty air?

• Smog and soot worsen asthma and trigger attacks. There is some evidence that ozone (a main ingredient in smog) and diesel exhaust particles may even cause asthma in some cases.
• Other triggers for asthma attacks include nitrogen oxides, formaldehyde and environmental tobacco smoke, and biological agents such as respiratory infections and allergens. Other toxic air contaminants like pesticides are suspected of contributing to asthma attacks but have not been conclusively proven to do so.
• Nearly two-thirds of those suffering from asthma live in an area where at least one federal air-quality standard is not being met.

How bad Is the asthma epidemic?

• Asthma is the nation's fastest-growing chronic disease and afflicts more than 22 million Americans.
• Asthma rates among children under age four have skyrocketed 160% between 1980 and 1996.
• The number of Americans with asthma has more than doubled in the past 15 years.

What are the costs of asthma?

• Every year, asthma is responsible for 9 million visits to health care professionals. In 2000, more than 1.8 million emergency room visits (including 728,000 visits for children under 17) and more than 460,000 hospitalizations were attributed to asthma attacks.
• More than 4,000 people lose their lives each year from this disease (with African-American children five times more likely to die than Caucasians).
• The economic burden of asthma has been estimated at $14 billion in 2002.
• Asthma is one of the leading causes of school absenteeism, accounting for over 14 million missed school days annually.
• Families with an asthma-afflicted member suffer a severe emotional toll, through lost sleep, disrupted routines and restricted activities. Many families may also suffer undue financial burden with high medical bills.

How the 1996 Olympics helped reduce asthma attacks in Atlanta

A strong case for the importance of ozone in triggering summertime asthma attacks comes from a study of Atlanta during the 1996 Summer Olympics. To reduce traffic congestion downtown during the 17 days the games were being held, the city enhanced public transit, closed downtown to private cars and encouraged businesses to promote telecommuting and alternative work hours. The study found that daily peak ozone levels dropped 28% and hospitalizations for asthma fell by almost 20% during that time.

The Atlanta case demonstrates a link between air quality and the prevalence of asthma attacks, and offers evidence that reducing air pollution is a powerful means of combating this medical scourge.

What Environmental Defense is doing

Our team of health and air pollution experts is leading the fight to clean up unhealthy pollution from tailpipes and smokestacks. Nationally, our team is working to get tight national emission standards for all diesel engines, including ships, locomotives and small engines like those on lawn mowers.

We work to ensure that Clean Air standards are implemented and enforced, from our national parks to congested cities. We push for cleaner transportation choices and better stewardship of highway projects.

Posted: 09-Jan-2006; Updated: 08-Aug-2007