Swimming outdoors is not only a fun way to enjoy the sun, fresh air and greenery, but it also relieves stress and boosts endorphins.
This creates a sense of well-being in addition to burning calories and strengthening muscles.
But along with the pleasures of outdoor swimming, there are some risks. Not only are swimmers at risk due to tides, currents and waves, nasty insects and bacteria can also lurk in the water.
And with raw sewage regularly draining into seas, rivers, and lakes, it can be difficult to find a safe place to paddle.
Of course, swimming in the pool comes with certain risks. Urinary tract infections, ear infections, and abdominal infections are among the most common illnesses diagnosed. Muddy puddles can also sting your eyes and contain all sorts of bacteria and germs, including urine, feces, and sweat.
But while swimming in open water obviously carries different risks than swimming in a pool, the question of where is the safest place to swim may not seem obvious.
Unlike swimming pools, where the water is carefully monitored, the composition of outdoor water is constantly changing. This means that chemicals can enter wild water from nearby farms or industrial areas, animals can defecate in the water, and in some areas human sewage can be legally or otherwise dumped into the water.
Warning signs of local hazards may not be present, and the presence of toxic substances may not be obvious. When in doubt about the chemical safety of street water, it is better not to enter it. If the water doesn’t look or smell good, trust your instincts.
There are also natural hazards to outdoor water compared to swimming pools, especially in summer. Blue-green algae are a type of bacteria found naturally in lake ecosystems. During warm summers, the algae tends to grow and form a green foam (known as a bloom) on the surface of the lake. Blue-green algae blooms can release toxins that are harmful to humans and sometimes fatal to pets.
Swimming or ingesting water containing algal bloom toxin can cause skin rash, eye irritation, severe gastrointestinal upset, fever, and muscle and joint pain.
bacteria and viruses
Diarrhea is the most common illness associated with open water swimming, often due to sewage pollution. You get sick if you swallow contaminated water, which can contain bacteria and viruses such as E. coli and norovirus.
Rats living in streams near freshwater rivers or canals can carry the bacterial pathogen Leptospira in their urine, which causes leptospirosis (Will’s disease). Infection occurs when soil or water from a lake, river or canal containing the urine of infected animals is ingested.
Leptospirosis can damage the liver and kidneys and can be fatal if left untreated. If you develop flu-like symptoms or jaundice within two weeks of swimming in a river or canal, it may be a good idea to ask your doctor to test for leptospirosis.
In the sea, a 2018 study found that people who swam in sea water were more likely to develop ear, nose, throat and gastrointestinal infections than those who stayed on the beach. Therefore, it is recommended to wash your face after swimming in any open water and, of course, before eating.
When you add it all up, even with the possibility of people urinating and defecating in the pool, a managed pool will always be a safer swimming environment. Especially when you consider things like jellyfish stings and the added risks of swimming in cold water.
Compared to a pool, wild swimmers are more likely to get sick from swimming in open waters, where potential disease germs will always be present. Swimming pool water with appropriate levels of chlorine disinfection and pH maintenance is less likely to contain infectious microorganisms and is therefore a safer environment for recreational swimming. Swimming pools also reduce the chance of injury and drowning as there are trained lifeguards and safety equipment.
Perhaps then a managed outdoor pool offers the best of both worlds – swimming with the sun on your back in a healthy environment.
The report was prepared by Primrose Friston, Senior Lecturer in Clinical Microbiology, University of Leicester.
Source: Science Alert