You can do your heart and lungs a favor by following this advice from the California Institute of Technology:
* Don't exercise outdoors during a smog alert. Air pollution indexes above 300 are considered unhealthy for most people. Indexes over 100 are unhealthy for those who are sensitive to smog.
* Get a high-efficiency particulate (HEPA) filter for your home. It can lower particulates by as much as 76 percent, says the American Lung Association.
* Use the exhaust fan when cooking. Vent it to the outside.
* Get a vacuum cleaner equipped with HEPA filters. Or switch to vacuum bags labeled "microfiltration," as recommended by Health magazine.
* Don't allow people to smoke in your home.
* When air quality is good, open the windows to get more fresh air inside.
* Don't let your car idle inside an attached garage. Fumes can build up.