The asthma and car connection

May 6th was World Asthma Day. Since car exhaust can lead to asthma as well as global warming, we thought it would be a good time to highlight the importance of not idling your car or truck engine.

What makes idling especially bad for health is that drivers tend to idle in gathering places -- by sidewalks, schools, playgrounds, homes, and offices. Breathing in pollution close to the source is more dangerous than farther away.

Take a look at the evidence.

Tailpipe exhaust from both gasoline- and diesel-burning vehicles contains the pollutants that produce ozone when combined with sunlight and heat. Ozone occurs mostly during the summer months. A warming planet means more hot days and thus more ozone.

Breathing in ozone irritates and inflames your lungs, and repeated exposure can reduce lung function. There’s a lot of evidence that ozone makes asthma worse.

But the Children’s Health Study in California found evidence that ozone causes asthma. The study also found that children can suffer irreversible lung damage as adults from breathing smog.

On top of that, diesel exhaust contains particulate matter (soot). This has long been known to cause a variety of health problems, including aggravated asthma (see CARB report on health effects [PDF]).

As with ozone, there is evidence that diesel exhaust particles may cause asthma and not just worsen it.

California kids aren’t the only ones to suffer from tailpipe-induced asthma. A 2005 NYU Medical Center study showed that asthma symptoms among children in the South Bronx doubled on high-traffic days.

Conversely, reducing ozone can improve asthma rates. During the 1996 Summer Olympics in Atlanta, the city closed downtown to private cars for 17 days. During this time, daily peak ozone levels dropped more than a quarter and hospitalizations for asthma fell by almost one-fifth.

There’s no reason to idle your vehicle engine. As I explained in a previous post:

• Today’s engines don’t need a warm-up period.
• If you’re stopped for more than 10 seconds, your car uses more gasoline to idle than to restart.

Many cities, including New York, have laws against idling, but they’re rarely enforced. We need better enforcement, but we can make a difference with our own actions and behavior.

So in honor of World Asthma Day, switch off that idling engine. You’ll curb global warming pollution, save money on gasoline, and help everyone to breathe better.