If you’re worried that a day at the pool might ruin your tan, don’t worry: chlorine, used as a disinfectant in swimming pools, It has no effect on melanin (the molecule responsible for tanning). Pool water does not remove your tan and has no bleaching effect on our skin. If after a day at the pool you see your tan “faded” it is because prolonged contact with chlorine can dehydrate and dry out the skingiving her temporarily a duller, whitish appearance. Let’s see how in detail.
Why chlorine doesn’t ruin your tan
When we tan, our skin naturally darkens as a result of the production of melanin by melanocytes present in the base of the epidermis. This natural process is activated by the interaction with the ultraviolet (UV) component of the sun’s rays, with the aim of protecting the skin from their negative effects. It is therefore a protection mechanism. However, we reiterate that Exposure to the sun must always be accompanied by the application of appropriate sunscreens which guarantee better and safer protection from UV damage, even when we are already tanned.
There are several factors that can ruin your tan, but chlorine is not one of them and it does not lighten your tan. Chlorine does not interfere with the melanin synthesis process, nor is it able to degrade it once it has been produced. So why do we see our tan fade after a swim in the pool?
What are the effects of chlorine on the skin?
It is not just our impression if we feel our skin “tight” after a swim in the pool: chlorine in fact tends to dehydrate the skin,giving it a duller, whitish appearance. Although it is not yet entirely clear how it does this, it appears to be involved in the skin hydrolipidic film.
The latter is a sort of film that protects the skin surface, and is made up of a water soluble and a part lipid (of fats). The hydrolipidic film allows to maintain the functionality of the stratum corneum, the most superficial layer of the epidermis: it keeps it elastic, hydrated and compact and, thanks to the slightly acidic pH (5.5) and the presence of enzymes, it provides a first protection against bacteria and pathogens.
According to some studies, the chlorine present in swimming pools reduces the natural moisturizing factor (NMF) of the stratum corneum, the pH and the level of sebum of the skin. This leads to a reduction and dysfunction of the hydrolipidic film and to water loss (dehydration) of the stratum corneum itself, which is rougher and less compact, as shown in the image.
Furthermore, a damaged hydrolipidic film makes the skin more susceptible to attack by pathogens.
So, even if it seems like a paradox because we are immersed in water, the chlorine present in swimming pools, as well as the salt in sea water, can dehydrate our skin by unbalancing and diluting the hydrolipidic film. Dehydrated cells have a more whitish and opaque appearance, which makes us believe we have lost our tan, but in reality it is just a ttemporary lack of hydrationwhich can be restored with the use of hydrating products.
In addition to chlorine itself, other factors can also contribute to skin dehydration when swimming in a pool, including the water itself (which dilutes the natural moisturizing factor), the pH, the temperature of the pool and of course the time we spend soaking in it.
In the long run, if dehydration continues, the skin will tend to peel offlosing the cells of the stratum corneum that contain the melanin for tanning. But it is the flaking due to the lack of a correct hydration It’s the skin that causes us to lose our tan, not the chlorine itself.
Is Pool Chlorine Bad for You? The Risks of Using It
Chlorine is used as a disinfectant agent in swimming pools to prevent the formation and proliferation of bacteria and pathogens, thanks to its oxidizing action. However, it is precisely this oxidizing action that is the cause of potential damage to our organism: chlorine in fact does not distinguish bacterial cells from human cells and acts in the same way on both, creating problems for the eyes, mucous membranes (especially respiratory) and obviously also to the skin. In addition, chlorine reacts with organic residues present in swimming pools (such as urine, sweat, skin residues) to form by-products including chloramines, trihalomethanes and haloacetic acid, which are also irritating and toxic at high concentrations.
In addition to skin dehydration, more sensitive subjects or those with dermatological pathologies may have real irritationswith skin rashes, itching and inflammation linked to the presence of chlorine, even to the point of having serious skin rashes from contact (chlorine dermatitis).
However, there is no need to worry, because the chlorine levels in swimming pools and the disinfection methods provided for by the State-Regions Agreement on the hygiene and health problems of swimming pools, published in March 2003, ensure the safety of swimmers.
Sources:
S. Borbone (2010) Integrated Sciences. Sciences of Nature and Man. Earth Sciences-Biology-Human Body. For High Schools Franco Lucisano Editore
Seki, T., Morimatsu, S., Nagahori, H., & Morohashi, M. (2003). Free residual chlorine in bathing water reduces the water-holding capacity of the stratum corneum in atopic skin. The Journal of dermatology, 30(3), 196–202. Couto, M., Bernard, A., Delgado, L., Drobnic, F., Kurowski, M., Moreira, A., Rodrigues-Alves, R., Rukhadze, M., Seys, S., Wiszniewska, M ., & Quirce, S. (2021). Health effects of exposure to chlorination by-products in swimming pools. Allergy, 76(11), 3257–3275. Fantuzzi, G., Righi, E., Predieri, G., Giacobazzi, P., Mastroianni, K., & Aggazzotti, G. (2010). Prevalence of ocular, respiratory and cutaneous symptoms in indoor swimming pool workers and exposure to disinfection by-products (DBPs). International journal of environmental research and public health, 7(4), 1379–1391. Pardo, A., Nevo, K., Vigiser, D., & Lazarov, A. (2007). The effect of physical and chemical properties of swimming pool water and its close environment on the development of contact dermatitis in hydrotherapists. American journal of industrial medicine, 50(2), 122–126.
