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Wild swimming has become massively popular in recent times. Swimming outdoors is not only a fun way to enjoy the sun, fresh air, and leafy surroundings, it can also help reduce stress and raise our endorphins. This creates a feeling of well-being as well as burning calories and building muscle.
But along with the joys of swimming outdoors come some dangers. Wild swimmers are not only more at risk from tides, currents and surges, but there may also be nasty bugs and bacteria lurking in the water. And with untreated wastewater regularly flowing into the seas, rivers and lakes In the UK, my hometown, it’s hard to find a safe place to paddle.
Of course, swimming in a pool comes with its own risks. Urinary tract infections, ear infections and bugs are the most common ailments here. Dirty pools can also sting your eyes and harbor all sorts of bacteria and pathogens – including urine, feces and sweat. In many ways, a swimming pool is like a large bathroom filled with strangers.
But while it’s clear that swimming in open water carries different risks than swimming in a pool, the question of where is safest to swim may not be immediately obvious. So where is the cleanest place to take a dip: swimming pools, or rivers, lakes, canals and seas? Let’s look at the evidence.
Unlike swimming pools where the water is carefully monitored, outdoor water constantly changes composition. This means chemicals can leach into wild waters from nearby farms or industry, animals can defecate in the water, and in some areas, human sewage can be dumped. enter the water legally or otherwise (if you can see the pipe, do not enter).
There may be no local hazard warning signs and the presence of hazardous agents may not be obvious. When in doubt about the chemical safety of outdoor water, it is better not to enter them. If the water looks or smells bad, trust your instincts.
There are also natural hazards to outdoor water compared to swimming pools, especially in the summer. Blue-green algae are a type of bacteria naturally found in lake ecosystems. In the warm summer, algae tend to proliferate and form a greenish scum (called a bloom) on the surface of the lake. This blue-green algae bloom can release toxins that are harmful to humans and sometimes deadly to pets.
Swimming in or swallowing water containing algae blooms releases toxins that can lead to skin rashes, eye irritation, severe digestive upset, fever, and muscle and joint pain.
Diarrhea is the most common illness associated with outdoor swimming, often due to sewage pollution. You get sick if you swallow contaminated water, which can contain bacteria and viruses like E.coli and Norovirus.
Rats living in sewers near freshwater rivers or canals can also carry in their urine the bacterial pathogen Leptospira, which causes Leptospirosis (Weil’s disease). Infection occurs if soil or water from a lake, river, or canal containing the urine of an infected animal is swallowed, gets into a swimmer’s eye or cut.
Leptospirosis can cause liver and kidney damage, and can be fatal if left untreated. If you develop flu symptoms or jaundice within two weeks of swimming in a river or canal, you should ask your doctor to be tested for Leptospirosis.
As for the ocean, a 2018 study found that people who swim in seawater are more likely to develop ear, nose, throat, and digestive system infections than people who stay on the beach. So you should wash it off after swimming in any outdoor water and certainly before eating.
When you add it all up, even if there is a chance that people pee and poop in the pool, a managed pool will always be a safer environment for swimming. Especially when you consider things like jellyfish stings and the additional risks of swimming in cold water.
Compared with swimming in a pool, people who swim in the wild are more likely to get sick while swimming in open water because there will always be potentially disease-causing bacteria.
Pool water, with the proper level of chlorination and pH maintained, is less likely to harbor infectious microorganisms and therefore presents a much safer environment for recreational swimming. Injuries and drownings are also much less common in pools with trained and properly equipped lifeguards.
Then, perhaps, a managed outdoor pool offers the best of both worlds – you get to swim in the sun in a hygienic environment.
