Itchy skin, irritated eyes, brittle hair, breathing difficulties--who would sign up for that kind of workout? Yet that is the reality for many who swim in indoor pools. As a toxicologist, I've been asked repeatedly whether the chlorine in swimming pools is unhealthy. But until now, I haven't taken up the issue. After all, who wants to point fingers at something with so many benefits? Indoor swimming is a great form of exercise, especially in the cold, dark winter months. However, the hazards associated with pools keep popping up like weeds in the flower bed. The news of a six-year-old boy nearly dying from a Nebraska motel pool has pushed me over the edge into the witches' brew of swimming pool toxics.
Pool water is a complex bit of chemistry that all begins with an old friend, that double-edged sword called chlorine. Gallons of chlorine are added to pools in the form of bleach to kill off bacteria. Without a disinfectant like chlorine, swimming pools would be an infectious disease outbreak waiting to happen. The flip side is that chlorine is highly reactive; it not only kills bacteria, but also combines with organic chemicals coming from people's bodies. Yes, humans release sweat and sometimes other excretions into the pool, which is where the chemistry really gets sticky. These reactions create chloramines and trihalomethanes (THMs), a brew of toxic chemicals that are the culprits behind all the dry skin, frizzy hair and heavy chlorine odor.
Not Just Dry Skin
Worst of all, these chlorine byproducts are volatile. Like swamp gas emerging out of a lagoon, the chloramines and THMs waft out of the pool and into swimmers' lungs. And they are just as harsh, if not harsher on airways than on skin. The lung irritation can lead to asthma, causing both new cases and the worsening of pre-existing disease. Studies in Europe have shown that lifeguards at chlorinated pools have greater rates of asthma. It appears that young children are most vulnerable. Those under age seven had the greatest odds of developing asthma from indoor pools, with the risk increasing with more frequent visits. The evidence has evolved to the point where researchers have given it a name: the swimming pool hypothesis of asthma. Yet this health concern pales in comparison to the acute, life threatening illnesses that have occasionally been seen at indoor pools.
What Happened in Nebraska?
On Christmas Day 2006, a family stayed at a national chain motel that...