Too many baths are unhealthy

How unhealthy are swimming pools?

Water disinfection

How unhealthy are swimming pools?

From Hildegard Tischer


Swimming is good for your health at all ages. However, the advantages of exercise are offset by the disadvantages of water disinfection. Swimming pool visits have been linked to an increased risk of allergies and asthma.


During the holiday season, a large number of water rats huddle together in the pools of the municipal swimming pools. Each of them brings microorganisms into the water via hair flakes, skin particles, sweat, sun creams and cosmetics, which in such a concentration are not conducive to the health of those taking a bath. UV protection preparations in particular pollute the water considerably. In addition, there are so-called humic substances, i.e. soil components that stick to the feet of bathers or get into the pool with fresh water. There is no public bathroom without disinfection. The chlorine used for this not only causes the typical swimming pool odor, but also irritates the eyes and respiratory tract. Even so, it is used because, compared to other disinfectants, it does the least harm to humans and it is very reactive. It immediately binds to microorganisms, preventing them from multiplying and cleaning the water as quickly as possible.


Irritant by-products


In the course of these chemical reactions, however, so-called disinfection by-products are also formed. These include chloramines and other nitrogen compounds, trihalomethanes, the best-known representative of which is chloroform, haloacetic acid and other substances. These evaporate so that bathers absorb them with the air they breathe.


Various studies suggest that children who go to the swimming pool frequently have an increased risk of allergic asthma. A team led by Dr. Alfred Bernard from the University of Brussels found in several studies. In one of these, the Belgians were able to show, for example, that asthma illnesses increase with the pool density of a region. In a more recent study they showed that baby swimming increases the risk of both asthma and chronic bronchitis (Pediatrics 2007, Doi: 10.1542 / peds.2006-3333).


However, a Norwegian study published in May only confirmed this connection to a limited extent (Acta paediatrica, Doi: 10.1111 / j.1651-2227.2008.00756.x). Only children whose mother suffered from asthma or an allergy were slightly more likely to suffer from respiratory illnesses due to baby swimming than in unaffected children. And even in this pre-risk group, the effect was very small. Among all children with such predisposition, 47 percent of the baby swimmers suffered from respiratory problems and 44 percent of the others. "The difference of 3 percent is not great," comments Dr. Ulrich Fegeler, Federal Press Spokesman for the Professional Association of Pediatricians (BVKJ), the result.


However, he advises these mothers not to go swimming with their child too early. "Chlorinated baths can possibly attack the not yet fully developed lung tissue and lead to increased respiratory infections." Fegeler points out that children would not have important developmental advantages from baby swimming anyway. Because at this age children could not yet learn to swim, such courses were mainly for fun.


On the other hand, Dr. Andreas Hellmann, Chairman of the Board of the Federal Association of Pulmonologists and former competitive swimmer. "Chlorine can certainly increase the risk of asthma, allergic rhinitis or other respiratory diseases or exacerbate existing asthma," he says. But that applies to every other pollutant in the air that irritates the mucous membrane. On the other hand, he does not rule out that the chronic rhinitis that competitive swimmers suffer from is related to chlorine exposure.


The connection between chlorine, disinfection by-products and respiratory diseases does not seem clear at all. Some of the studies also contradict each other. In this case, foreign studies are difficult to compare with German studies from the outset because the limit values ​​for chlorine in this country are up to ten times below those in other countries. But even one and the same research group came to different results: The Helmholtz Institute in Munich showed that adults between 35 and 74 years of age, who were often in the swimming pool in their childhood and adolescence, suffer more from hay fever. In another study, the researchers led by Joachim Heinrich examined the connection between baby swimming, asthma and allergic rhinitis in children of six years old - and found none.


The advantages outweigh the disadvantages


»The allergy risk has increased overall. It is unclear what role bathrooms play in this, ”says Hellmann. He believes that not swimming because of the risk of respiratory infections or allergies is completely wrong: "The advantages far outweigh the disadvantages." Swimming is the ideal sport, especially for asthmatics. You can switch to quarry ponds or rivers, but you are simply exchanging one risk for another. There may be many more bacteria in natural waters.


It is important to dose the chlorine as minimally as possible, but this can prove difficult because sometimes more and sometimes fewer bathers cavort in the pool and the water pollution fluctuates accordingly. There seems to be agreement on one point: The water rats themselves can contribute indirectly to reducing chlorine by showering themselves thoroughly before jumping into the pool, preferably with soap, so that sunscreen comes off. This also applies to private pools.