Q What causes the air-quality alerts we've been experiencing? What is a person supposed to do when there's an alert?
A At this time of winter, fine particles are likely to be the problem. They are typically caused by burning fossil fuels and wood, and some natural sources. Although particulates can cause alerts at any time of the year, winter's temperature inversions and stagnant air help trap them. That's what we've been experiencing recently.
Health officials don't advise people to go inside to reduce their exposure, because outside air ends up inside.
Every time we drive a car, heat our homes or use electricity, we increase the amount of air pollution. And recreational back-yard fires don't help, either. In every air alert, the public should reduce driving, idling and electricity use and postpone making recreational fires.
How you respond to protect your health depends on the type of pollution, which is linked to the season.
Summer is ozone season. Ozone is created when volatile organic compounds (VOCs) and nitrogen oxides mix in hot, sunny weather. Ozone exposure affects lung function. When ozone levels are high, people are advised to go indoors into an air-conditioned environment. Air conditioning and contact with surfaces can scrub out ozone, thereby reducing ozone exposure.
But that's not the case with fine-particle pollution. You can't hide from it, and you shouldn't run. The harder and more often you breathe, the more particles will enter your lungs, increasing your risk of symptoms. Of course, since exercise is also important for your health, you'll want to determine a balance that's right for you.
The particles can trigger respiratory problems such as asthma. People with existing respiratory and heart problems are considered the most susceptible. Young children also are advised to reduce activity, in part because their lungs are still developing.
