Every now and then we run an advertisement for a product called ShowerSafe, a showerhead filter that helps reduce the absorption of chlorine in tap water. http://www1.youreletters.com/t/369627/2660685/788768/0/
The latest ShowerSafe ad prompted this e-mail from an HSI member named Mary: "I read your article on chlorine and have a concern. I do water aerobics 3x a week for an hour. If a 10 minute shower is bad, what can that be doing?"
Good question. When I checked in with HSI Panelist Allan Spreen, M.D., and posed Mary's question, he started at the top: the scalp, noting that the pores of the scalp are highly absorbent.
Dr. Spreen: "As someone who spent a TON of time in chlorinated water (and handling chlorine levels), there is NO question that swimming in American pools is far worse than showering...the chlorine levels are much worse in the pool. That's haunted me for years.
"Even worse, however, would be a hot tub...they are positively loaded with chlorine.
"I say 'American' pools, as in Europe they refuse to use chlorine or bromine, preferring the more expensive process of ozonation. My feeling is the US can't afford to have that bit of news get out, as people will then start to question their municipal (chlorinated) water supplies.
"So, yes there's scalp absorption (plus inhalation, don't forget) in a shower. And never, ever, get in a hot tub unless it's ozone treated (which you won't find in the US, far as I know)."
In the e-mail Dr. Spreen sent, he mentioned a book titled "Coronaries/Cholesterol/Chlorine" by Dr. Joseph Price. The book explains how chlorine intake contributes to narrowing of the arteries.
Dr. Spreen: "Price found that American kids dying in car wrecks at home had far less atherosclerosis than kids the same age killed in Vietnam. His conclusion was that the only thing different was all the chlorine tablets the troops had to dump into all water supplies to be able to drink available water over there.
"He then took chickens (which for some reason have arteries like humans) and tested chlorinated and non-chlorinated water on them. He found that the highly reactive nature of the chlorine molecule scars the arterial intima [the inner lining of the artery]. The body protects itself by painting a thin film of cholesterol over the damaged area. It's not the cholesterol that kills, it's the continual need for protection against the scars that eventually gets out of hand."
In "Coronaries/Cholesterol/Chlorine" Dr. Price offers another key point to support the link between chlorine exposure and atherosclerosis.
Dr. Prince notes that heart disease is a modern health problem. We're told by mainstream nutritionists that high-fat diets are to blame, but high-fat diets were common in the 19th Century while heart disease was rare. Meanwhile, the steady growth of heart disease rates throughout the 20th Century parallels the steady increase in the use of chlorine in our water, paper, clothing, insecticides, paints and cleaning products.