This week I saw media reports on two scientific studies, which warned of additional health risks. My first thought was "Don't we have enough to worry about?" As I had more time to reflect, I began to wonder just how good these studies were. In other words, how scientific were these scientific studies.
The first study warns that too much chlorine in swimming pools can lead to increased risk of asthma in children who have spent as little as a hundred hours in the pool. To be a true scientific study, it would have to 1) span several years, 2) include controls, and 3) allow for other possible explanations. As usual, the media presentation did not allow me to judge whether or not the study followed any of these criteria.
The second study warns that shower heads can pose a health risk. This is due to a marked increased presence of a bacterium in shower heads over what is found in the water supply. This bacterium can cause respiratory problems. The author speculated that the observed increase in respiratory problems in recent years may be linked to the increase in the use of showers over baths. My problem with this study is no evidence was presented to show the bacterium moved from the shower head to the individual who is showering.
Later, I leapfrogged to a new theory. Maybe, the asthma in children is not caused by the chlorine in the swimming pools. Maybe, the asthma is caused by the shower heads that have the bacterium. Most people who enter or leave a swimming pool shower rather than take a bath.
I hope these studies were conducted with proper controls and that their conclusions are based on properly observed data.
