Hold Your Breath When The Bus Goes By

Timothy B. McCall, M.D.

Just having returned from a trip to India, I was greeted by news reports of a new Journal of the American Medical Association study linking air pollution to deaths from lung cancer and heart disease. This really caught my attention since the air quality in a few of the Indian cities I visited was the worst I’d ever experienced.

Polluted air contains the soot from partially combusted fossil fuels, factory smokestack emissions and hundreds of other chemicals, many of them either unknown or poorly studied. Besides lung cancer and heart disease, studies have linked poor air to everything from asthma to high blood pressure.

Not all of us have the option of living in the countryside where the air tends to be much cleaner. Still you may be able to lower your risk. Here’s what I suggest:

• Choose When To Be Outside. Air quality in cities tends to be worst on hot and hazy days, mid-day and during rush hour. If possible adjust your schedule accordingly--especially if you plan to exercise. Breathing rapidly, your lungs may be filtering as much as twenty times the quantity of air—and pollutants--as they would with quiet breathing. My advice is to exercise early mornings or late evenings (though the latter could interfere with sleep). Otherwise you’re probably much better off working out in an air-conditioned health club.
• On Heavily Polluted Days, protect yourself. When riding auto-rickshaws, the three-wheeled, diesel-powered transportation of choice in much of India, I often breathed through a handkerchief to filter out some of the particulate matter from the air. Some bicycle commuters wear a surgical mask for the same purpose. These measures won’t completely eliminate the risk, however, as some pollutants pass through them. And speaking of filtering the air, whenever possible inhale through your nose. That way you’re using your body’s natural air purification system.
• Hold Your Breath When The Bus Goes By. If you’ve ever noticed the cloud of dark diesel exhaust that wafts out of many buses and trucks, you’ve probably been tempted to hold your breath. As long as you don’t have a lung or heart condition that makes breath-holding dangerous, I think it’s a good idea. If I see I’m about to be exposed, I try to take a few deep breaths, then hold my breath till the air clears.
• Avoid Other Sources of Air Pollution. As I pointed out in a prior column indoor air can be as or more polluted than outdoor air. Reduce your risk by minimizing the use of solvents, aerosol sprays and other chemicals in the home and by making your dwelling smoke-free. Air filters and keeping plenty of houseplants can also help.
• Get Your Antioxidants. Since some of pollution’s toll on the body may be due to toxic free radicals, antioxidants like Vitamins C and E may offer some protection. While low doses of supplements may be worthwhile, I favor getting as many antioxidants as possible from a diet rich in fruit and vegetables. And just a little chocolate.

Return to Bottom Line Health Columns