We have all walked into a swimming pool facility, health club, or small motel and immediately recognized that “chlorine” smell emanating from the pool. We have grown to accept the odor and the other side effects of chlorine disinfection as the price paid to have a sanitary swimming pool. The odor and many of these side effects are not actually caused by the chlorine, but are the by-products of chlorine disinfection. Chlorine and bromine are common aquatic system disinfectants and are very effective at killing bacteria. They, and their halogen brothers fluorine and iodine, are all effective sanitizers because they are strong oxidizers (oxidation is the way bacteria is killed). Halogens, like chlorine, are all one electron short of filling their outer electron shell. They are always looking for another compound from which to steal an electron (oxidize). However, their oxidative power is not limited to just attacking bacteria.
Disinfection by-products (DBP) are formed when chlorine oxidizes organic compounds. These organic compounds are found in bacteria and many are critical for the bacteria to live and thrive. However, a lot of organic compounds are naturally present in our water, and putting people into the water introduces even more of these materials (dead skin cells, sweat, urine, etc). When chlorine interacts and oxidizes these organic compounds, it results in a tremendous amount of newly created compounds…but, these now contain chlorine (DBP). We generally classify some of these as combined chlorine or chloramines. It has now been established that many of these DBP are toxic, and while most remain in the water, some are quite volatile and released from the water into the air (i.e. chloroform). These DBP are what we recognize as that “chlorine” smell.
In short, chlorine is going to cause a reaction with anything in its path, and some of these reactions are going be toxic. So, that funky “pool smell” isn’t the chlorine. It’s the dark side of chlorine’s work.
Research at Embro Corporation (Creative Water Solutions’ sister company) is actively investigating the process by which DBP are formed, and the levels of DBP in swimming pools and spas. Our early results have demonstrated that Sphagnum moss leads to a reduction in DBP levels within the first few months of use in a swimming pool. Pointing to the importance of this research are the increasing numbers of scientific articles documenting production of toxic DBP in aquatic systems. They illustrate increased health problems for those experiencing high exposure to these compounds, including competitive and avid recreational swimmers. Stay tuned to our newsletter and website for the newest results of our research in this area.