Dear Dr. Whitaker,
"I swim in a public pool for exercise, and I'm worried about the chlorine. Is there anything I can do to protect myself?"
— SN

Dr. Whitaker's response:
Chlorine is a highly poisonous chemical used as a bleaching agent and germicide. It has been added to water as a disinfectant since 1908, when it was found to significantly reduce the incidence of infectious diseases in cattle in the Chicago stockyards.

I've often warned against drinking chlorinated tap water, which is linked to a host of ailments, including bladder and rectal cancer, miscarriages, and coronary heart disease. But believe it or not, swimming (or bathing or showering) in chlorinated water exposes you to much higher levels of chlorine than drinking it. Chlorine is readily absorbed through your skin, which is your largest organ — in fact, you absorb twice as much chlorine through your skin than you do when you drink it. That's not all. Because chlorine is a heavy gas, it tends to settle on the surface of the water. So every time you take a breath, you inhale even more of this noxious chemical. Obviously, indoor pools are more of a problem than outdoor pools in this regard. And your own shower is likely even worse, since you're inhaling chlorine-laden steam in a small enclosed area. According to research presented at the American Chemical Society, your exposure to these chemicals by breathing the air in and around your shower is up to 100 times greater than by drinking tap water.

There are several things you can do to minimize the harmful effects of chlorine. Wear a swim cap to protect your hair, and swimming goggles or a mask to protect your eyes. Don't linger in an indoor pool area. After your swim, shower quickly and thoroughly. And to protect your cells from free-radical damage caused by chlorine, be sure to take high-dose antioxidants: vitamin A (5,000 IU), beta-carotene (15,000 IU), vitamin E (800 IU), vitamin C (1,500 mg), and selenium (200 mcg).

Also, if you have your own swimming pool, check into alternative methods of disinfection.

By the way, I also recommend installing a shower filter in your bathroom. A quality shower filter will remove up to 99 percent of the chlorine from your shower. In addition to protecting your lungs from noxious chemicals, it will do wonders for your hair and skin. I have a water filter on my shower head at home, and one thing I always notice when I travel is that after showering, my skin smells of chlorine.