There are several chemical processes associated with the water quality of swimming pools. But the most important is, without a doubt, disinfection with chlorine compounds.
"Swimming pool chlorine" is a chemical disinfectant with an unfair bad reputation. A misunderstood friend often linked to unpleasant smells, skin irritation and red eyes.
In fact, the presence of a disinfectant is essential since swimming pools are excellent places for the growth of pathogenic microorganisms and a poorly disinfected pool exposes us to a number of hazards caused by viruses, fungi and bacteria.
For example: dermatitis, athlete's foot , ear and skin infections, legionnaire's disease, gastroenteritis and many other unpleasant ailments!
This is where chemistry gets in! In a properly disinfected swimming pool the majority of these pathogenic micro-organisms can't survive more than 30 seconds!
The most common swimming pool disinfectants are hypochlorite calcium and chlorinated derivatives of isocyanuric acid. In contact with water, these substances form highly aggressive disinfectants for these micro-organisms, destroying them! And we don't even need a lot of disinfectant: 4 parts per million, something like a teaspoon per a thousand litres of water!
It's not easy to maintain appropriate levels of these substances in swimming pool water. They are unstable and degrade when exposed to light.
But what makes it worse are the swimmers! The chlorinated disinfectants also react with fats and proteins transported in the body of the users of swimming pools: sweat, cosmetics, sunscreens, oils and lotions. Even dead skin cells are dispersed in the water and react with the disinfectant, reducing its concentration and its protective effect.
And if the level of disinfectants decreases too much, these reactions will begin to produce harmful chemicals, the "chloramines", the true responsible for eye and skin irritation and the "smell of swimming pool ". This unpleasant odour (also known as " smell of chlorine ") is actually the smell of chloramines and indicates a pool in poor health for lack of chlorine!
Next time you enjoy the delights of a swimming pool, make sure there is a good level of chlorine and dive with confidence, knowing that chemistry protects you!