Can You Get Sick From Dirty Pool Water?
Can you get sick from swimming in dirty or poorly maintained swimming pool water? This is a question that I was asked recently while traveling in Asia. On of the hotels that I was staying at had a fairly nice swimming pool, however the water was turbid and clearly not safe to swim in...at least according to any first world water quality standards. This particular pool was located in Siem Reap Cambodia, which is a very hot place, and so it can be temping to use even questionable swimming pools. When I arrived at this hotel the floor of the pool was still visible (about two meters / six feet deep) but after a few nights of heavy rains the pool turned completely green. You could see only perhaps 12 inches down into the water at most. What was amazing to me is that people were still swimming in it!
During this hotel stay I met some other travelers who were enjoying the pool on a daily basis. They were interested to know why I was not using the pool also since it was so hot, and they seemed surprised to learn that swimming in poorly treated pool water can make you sick. Once I explained to them that this pool would be closed to the public if it were located anywhere in Canada or the USA they became concerned about how much time they had spent in the water. As a swimming pool specialist I simply can't ignore the potential concerns like an average person might be able to. In the moment of this conversation with these fellow travelers there was simply not enough time to highlight the areas for concern when swimming in dirty pool water, which is why I decided to write this article for them...and for any other travelers or swimmers wondering if it is safe to go in the water.
Dangers Of Unsanitized Pool Water
Some people are risk takers while some people are not. These warnings about what can happen when you swim in dirty water will fall on many deaf ears, however many people simply do not understand how much they are actually risking by swimming in questionable water. For example, this group of travelers I was speaking with stated that they assumed the hotel would close the pool if it was not safe. I found this line of thinking to be absolutely hilarious, since I am quite sure that safety is not a paramount concern anywhere in Cambodia. Only 30 minutes away from where we were standing while having this conversation you could pay $200 USD to shoot a live cow with a rocket launcher...I think it is safe to say that "safety" is a rather loose term anywhere in Cambodia.
Waterborne illnesses are some of the most common ways to get sick anywhere around the world. In fact, according to the World Health Organization, over three million people per year die from water related diseases, which makes it the leading cause of death in the world. More people get sick and die from dirty water than from war, or cancer, or car accidents or any other means. If this does not cause you to take dirty water more seriously then nothing will. Of these illnesses and deaths, the vast majority are due to organisms introduced by sewage. This can include drinking water sources contaminated by runoff, but can also include birds or other wildlife taking a dump in your hotel pool!
Cryptosporidium - Crypto is one of the most insidious parasites that you should be concerned of in dirty swimming pool water. Crypto infection can cause vomiting, diarrhea, stomach cramps, fever and dehydration. What makes crypto such a concerns is that it is one of the most resistant parasites to chlorine. The vast majority of waterborne bacteria, viruses and parasites will all be killed within 60 seconds after exposure to 1ppm of chlorine. Crypto has a touch outer shell layer which makes is much harder for chlorine to kill. Typically it takes sustained chlorine levels at ten times this value (10ppm or higher) over 12 hours to kill crypto. This is one of the reasons why super chlorination is recommended for residential pools and required for commercial pools in Canada and the USA. I have very little confidence that pools in Cambodia receive this same level of chlorine treatment so even under optimal conditions crypto is a concern.
Giardia - Similar to crypto, giardia is a parasite that can cause extreme stomach distress, diarrhea, fever, vomiting, bloating and fatigue. Often called "beaver fever" giardia is typically found in the feces of contaminated animals including beavers, rats, dogs, and of course, humans. Symptoms of giardisis can take up to 16 days to show up, and symptoms can last as long as a month.
Dysentery - Dysentery is any presentation of infectious bloody diarrhea and is caused by contamination of water from infected human feces. This is one of the reasons that you often see signs on commercial swimming pools about not going in the pool if you have had diarrhea any time in the past 10 days. Symptoms of dysentery include profuse, bloody diarrhea, fever, intense stomach pain, weight loss and dehydration. Dysentery is transmitted from fecal to oral contamination.
Salmonella - Salmonella is a bacteria which can be transmitted by unsanitized water and comes from infected human of animal feces including chickens, cows, dogs, cats, pigs, sheep, turtles, snakes and humans. Similar to the other illnesses, symptoms of salmonella include vomiting, diarrhea, fever, abdominal pain and dehydration.
E-Coli - E-coli, or Escherichia Coli O157:H7, is one of the most common concerns for swimming in dirty water. Escherichia coli is a bacteria which is harmless and lives in the digestive system of both humans and animals and is transmitted via fecal contamination. The specific O157:H7 strain is the one you need to be concerned with as this can cause bloody diarrhea and abdominal cramps, and in up to 7% of cases can result in hemolytic uremic syndrome which results in liver failure.
Typhoid Fever - Typhoid fever is another form of Salmonella which only lives in humans. Once ingested, the typhoid infection spreads to the bloodstream and causes sustained fevers at 103 or 104 degrees. While rare in developed Countries, typhoid is still common in developing countries. Of additional concern is that some people can recover from typhoid fever while still carrying the S. Typhi bacteria and infecting others.
Cholera - Cholera is intense digestive distress and profuse diarrhea caused by the Vibrio cholerae bacteria. In severe cases leg cramps and vomiting are also noted, with the potential for death from dehydration and shock happening within hours without treatment.
Hepatitis A - Hepatitis A can be passed through contaminated water entering your mouth and can result in yellowing of the skin, dark colored urine, vomiting, stomach distress and fever. Hepatitis E is also a concern from dirty water and can take from two to eight weeks from contamination until symptoms begin to present.
Campylobacter - Campylobacter bacteria is considered the most common cause of bacterial gastroenteritis around the world. Something unique about this bacteria is that unlike the others on this list which are rare or on the decline in developed countries, the incidence of campylobacter bacteria infection is steadily rising in developed countries in recent years. While the main source of this bacterial contamination is from undercooked and poorly handled food, it is also transmitted by ingesting contaminated water.
In addition to these serious illnesses, swimming in dirty water can also cause a host of ear, eye, nose and throat infections. Swimmers itch, which is cause by cercarias larvae, cyanobacteria from blue-green algae as well as Legionellosis from the Legionella bacteria are all a concern from untreated or poorly treated water. So which of the illnesses on this list sound like something that you want to contact for yourself? Even worse, imagine coming down with one of these illnesses while traveling so far from home or in a Country with limited access to health care!
How To Tell If Pool Water Is Safe To Swim In?
The unfortunate thing is that no amount of looking at pool water will be able to determine if any of these parasites, bacteria or viruses are present. This is why it is important to err on the side of caution when deciding whether or not to take a dip in questionable pool water. When used correctly, chlorine will prevent all of these illnesses, which is why pools without chlorine are far more dangerous than most pool owners realize. Chlorine, in most cases, is the only line of defense that you have to protect you from getting sick, and so checking the chlorine level of the water is the only real way to know if the water is likely safe or not...and even still there is some risk to be had.
This is the reason why I travel with chlorine test strips so that I can test the water of any pool that I am thinking to use. Sure this would seem unreasonable to anyone not familiar with water chemistry and clean water standards, but most swimming pool workers do the same as me - test the water for chlorine or simply do not go swimming. Assuming that you do not have a chlorine test kit with you when you travel, as most people do not, the next best thing you can do is arrive at a reasonable conclusion based on how the water in the pool looks. Just because water looks clean does not mean that it is clean, however a more reasonable conclusion can be drawn if the water does not look clean. If the water in the pool looks hazy, turbid, green, or anything other than crystal clear, then you can be reasonably certain that it is not clean and you likely should not be swimming in it.
If you do decide to swim in questionable water then at the very least you should go out of your water to not allow the water into your eyes, ears, nose and especially mouth. This might not guarantee your safety but should allow you to cool off a little bit while limiting your risk of exposure to one of these nasty bacteria. You are much better off to forgo the dip in the pool and stay healthy than to risk having your entire vacation ruined (if not your health) by swimming in dirty or poorly treated swimming pool water.
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