Toxins in Chlorinated Pools | Natural Health Blog

The Danger of Swimming in Chlorinated Pools


If you wait long enough, “science” often catches up with the alternative health community. In this case, it only took several decades for researchers to confirm what alternative healers like Jon Barron have been saying almost forever — that if you’ve been splashing around in a chlorinated pool, you may be subjecting your body to some serious toxins.

A recent study at the University of Cordoba in Spain found that a group of by-products of chlorine called haloacetic acids (HAAs) was present in the urine of swimmers less than 30 minutes after they emerged from the pool.1  This dangerous chemical is only allowed in restricted amounts in our drinking water by the Environmental Protection Agency because it has been associated with cancer and birth defects in other research.

There were 49 participants — both children and adults — in the study.  All of them either swam in or were pool workers employed at indoor and outdoor chlorinated pools.  When their urine was tested, the HAAs showed up 20 to 30 minutes after the chlorine exposure took place.  They continued to appear in the urine for up to three hours before they were fully excreted.

The scientists suggested that the vast majority of the contact with HAAs was most likely caused by the volunteers swallowing small amounts of the pool water as they swam.  However, inhalation and absorption through the skin clearly also created exposure, since not every subject actually entered a pool.

Unsurprisingly, those who swam stored up HAAs nearly four times as quickly as those who simply worked by the pools.  And children had higher levels of HAAs after taking a dip than the adults did, which makes sense since the younger the skin, the faster the absorption rates.  Therefore, the younger the child, the more dangerous the exposure to chlorinated pool water can be.

Chlorine is added to both the water we drink and the water of many pools because of its ability to kill bacteria for our safekeeping.  Ironic, then, that it breaks down in the water and creates these harmful HAAs.  Although the amount of chlorine put into a pool is supposed to be regulated, there is no way to oversee every pool in backyards, health clubs, hotels, community parks, and so on to know that the levels are anywhere near safe — if any such level actually exists.

The same concerns relative to bathing in chlorinated water also apply to swimming in pools with chlorinated water. It’s very bad, and you absorb a great deal of chlorine very quickly through the skin. Also, as I already mentioned, the younger the skin, the quicker the absorption — which means your toddler is at particular risk.  Incidentally, Jon Barron describes in Lessons from the Miracle Doctors an experiment you can perform at your convenience to see just how quickly you actually absorb chlorine through your skin.

Stop by your local swimming pool supply store and pick up a chlorine test kit. Fill a glass with some of your local tap water, or water from a chlorinated swimming pool, and test it with the kit. The water will change color according to how much chlorine there is in the water. Now, fill up another glass with water from the tap. This time, soak your hand in the water while wiggling your fingers about for 60 seconds before testing. Notice how the water now shows virtually no chlorine. In just 60 seconds, you absorbed all of the chlorine in the water into your body through your hand. The absorption factor is that dramatic.  And it’s not just toddlers with young skin that need to worry. Women should take special note that breast tissue is the most absorbent tissue in the body. Soak your breast in the same water, and it will clean out all of the chlorine in just 20 seconds.

So if you’ve got your own pool, you might want to consider keeping it clean without chlorine, or at least with minimal chlorine.  One of the most popular options now to avoid using chlorine is saline — or salt water — pools.  With this method, the pool is kept clean by adding a small amount of salt to the water every few months.  The water is pumped through a cell chamber that breaks down the salt into its components, which produce chlorine gas that cleans the water in the chamber.  The water is bacteria-free when it is once again released into the pool and the chlorine gas that had been formed is never released into the pool.

The initial cost of using salt to keep your pool clean is more expensive than a chlorine start-up, but since you don’t have to add it frequently, the costs become lower over time.  There is also much less overall maintenance with a saline pool.

Ionization is another method of keeping your pool clean.  Copper and silver coils that have been ionized, or become positively charged, are used in the pool to purify the water as it circulates.  The positive ions can kill much of the algae and bacteria that end up in the water, but pool experts still recommend using a very low dose of chlorine to be certain it’s fully sanitized.

Filters are an important consideration as well.  The right filter can help you use a much smaller amount of chemicals to keep the water pure.  Activated charcoal filters are probably the most effective, but are also the most expensive.  Filter cartridges require more maintenance but they cost less and should last for several years.

There are also chlorine-free chemicals available, but many of these are not any safer than chlorine itself.  Do your homework if you want to explore this option to ensure you don’t trade one toxic chemical for another.


1 Cardador, M.J. and Gallego, M. “Haloacetic Acids in Swimming Pools: Swimmer and Worker Exposure.” Environmental Science & Technology. 7 June 2011.  American Chemical Society. 8 August 2011. <>.

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