While most of us would rather pass at the prospect of swimming in a lake or river (because who knows what’s in there), we don’t often give a second thought to jumping into clear blue pools. If it looks clean it is clean, right? Well… not always. Our backyard or public pools may not look murky, but they often contain significant amounts of bacteria (or other types of harmful micro-organisms), and the chemicals we use to fight them are not full proof.

There are a number of disease-causing microbes that build up in untreated water, such as Escherichia coli (better known as E. coli), Salmonella, and parasites such as Cryptosporidium parvum and Giardia lamblia (Dewar 2010). Chlorine is the most commonly used chemical disinfectant to counter these organisms. But a recent article published by Chemical & Engineering News and titled “The chemical reactions taking place in your swimming pool”, stated that while these disinfectants are essential, “many of them react with organic material in the water—dirt, sweat, urine, and even skin moisturizers” to form another category of harmful chemical compounds called disinfection by-products (DBPs) (Arnaud 2016). So it’s not just about the what’s in the water, it’s also about what’s on your body.

People can be exposed to DBPs by coming into contact with water from a pool, as well as the air in that area. Although more research needs to be conducted in terms of the amount of exposure to DBPs needed to cause negative health implications, those who spend more time in swimming pools are more at risk to their effects.

So that’s the bad news… but since it’s unreasonable to expect that all people stop participating in something as fun and beneficial for cardio-vascular health as swimming, let’s speak about how to decrease the risks in your own pool.

One trick is not to overdo it with the chlorine. You just need enough of it to kill microbes, but too much of it results in excess chlorine that then avails itself to the creation of DBPs (Arnaud 2016).

We often shower after swimming – which is good, don’t stop doing that – but not many people shower before getting into a pool. Pre-swim showers help reduce the number of chemicals on your body for the chlorine to react with. In 2012 a study was published by the U.S. National Center for Biotechnology Information where the researcher remarked that swimmers, “even when they had been showering or swimming earlier in the day, after one hour of lying around they were as dirty as they had been when they first came in” (Keuten 2012). Therefore, it would be ideal to rinse yourself off again, prior to going back into a pool.

This might bring back memories of your first swimming instructor, but their age-old advice of not peeing in the pool and not swallowing the water is an important line of defence. The basics remain the basics for a good reason.

August 2016

While most of us would rather pass at the prospect of swimming in a lake or river (because who knows what’s in there), we don’t often give a second thought to jumping into clear blue pools. If it looks clean it is clean, right? Well… not always. Our backyard or public pools may not look murky, but they often contain significant amounts of bacteria (or other types of harmful micro-organisms), and the chemicals we use to fight them are not full proof.

There are a number of disease-causing microbes that build up in untreated water, such as Escherichia coli (better known as E. coli), Salmonella, and parasites such as Cryptosporidium parvum and Giardia lamblia (Dewar 2010). Chlorine is the most commonly used chemical disinfectant to counter these organisms. But a recent article published by Chemical & Engineering News and titled “The chemical reactions taking place in your swimming pool”, stated that while these disinfectants are essential, “many of them react with organic material in the water—dirt, sweat, urine, and even skin moisturizers” to form another category of harmful chemical compounds called disinfection by-products (DBPs) (Arnaud 2016). So it’s not just about the what’s in the water, it’s also about what’s on your body.

People can be exposed to DBPs by coming into contact with water from a pool, as well as the air in that area. Although more research needs to be conducted in terms of the amount of exposure to DBPs needed to cause negative health implications, those who spend more time in swimming pools are more at risk to their effects.

So that’s the bad news… but since it’s unreasonable to expect that all people stop participating in something as fun and beneficial for cardio-vascular health as swimming, let’s speak about how to decrease the risks in your own pool.

One trick is not to overdo it with the chlorine. You just need enough of it to kill microbes, but too much of it results in excess chlorine that then avails itself to the creation of DBPs (Arnaud 2016).

We often shower after swimming – which is good, don’t stop doing that – but not many people shower before getting into a pool. Pre-swim showers help reduce the number of chemicals on your body for the chlorine to react with. In 2012 a study was published by the U.S. National Center for Biotechnology Information where the researcher remarked that swimmers, “even when they had been showering or swimming earlier in the day, after one hour of lying around they were as dirty as they had been when they first came in” (Keuten 2012). Therefore, it would be ideal to rinse yourself off again, prior to going back into a pool.

This might bring back memories of your first swimming instructor, but their age-old advice of not peeing in the pool and not swallowing the water is an important line of defence. The basics remain the basics for a good reason.