C6 Tuesday, April 29, 2014
FITNESS & WELL-BEING Local swimming pools are well maintained, but swimmers still run the risk of infection, says Richard Lord
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s the weather heats up, inevitably more of us will fancy taking a dip in a pool, whether it be one of Hong Kong’s many public swimming facilities or a posh pool in a private housing development. Unfortunately, in doing so, we open ourselves up to the possibility of contracting all sorts of nasty little conditions that can affect everything from our skin to our eyes and ears, and from our respiratory system to our digestive system. “A pool is a confined tank,” says Terry Hung, specialist in otorhinolaryngology at Matilda International Hospital. “Unlike a sea or river, there’s no flow of water. It’s a communal thing, so whatever bacteria or germs people in it have can spread into the water and into other people.” Bacteria can enter the body when pool water is swallowed, or via the mucous membranes or breaks in the skin. Similarly, they can come from any number of different types of bodily secretion. One of the simplest ways to avoid infection, therefore, is to avoid responding to the call of nature while swimming – although, as John Yu, specialist in dermatology at Matilda, says, the worst perpetrators are the hardest to control. “Always use a different pool for small kids because they tend to pee everywhere,” he advises. According to a recent study by China Agricultural University and Purdue University in the US, published in the journal Environmental Science and Technology, the implications go beyond the obvious unpleasantness of swimming around in pee. The researchers found that the uric acid in urine
IN THE
SOUP Young children tend to pee in swimming pools and this can lead to an increase in harmful bacteria. Small children should use separate pools to safeguard the health of adults, experts say. Photo: Corbis reacts with the chlorine used to disinfect swimming pool water to create cyanogen chloride and trichloramine, poisonous byproducts that can cause everything from respiratory tract damage to childhood asthma, and can even cause long-term harm to the central nervous system and heart. Fortunately, that very same chlorine, also used in the footbath you step through before entering the pool, kills a large number of the nasties that are swimming around with you – but not all of them. “Most bacteria come from the gut, and most are killed by chlorine,” says Dr Seto Winghong, consultant microbiologist in the pathology department of the Baptist Hospital. “But there are some, especially parasites, that are chlorine-resistant – in particular cryptosporidium,” one of the more common causes of gastroenteritis from dirty water, along with giardia, shigella, the norovirus and some of the nastier strains of E coli.
Fortunately, there has never been an outbreak of cryptosporidium here, and like most of these pathogens, it’s easily avoided – just make sure you don’t swallow too much pool water. To avoid spreading digestive conditions, don’t go swimming if you have a stomach problem. Even if you’re feeling fine, though, faecal bacteria can be pretty tenacious. “If you’re considerate, you’ll shower before you go in the pool,” says Seto. It goes without saying that you should also have one immediately afterwards. Likewise, anyone suffering with a cold should steer well clear of the pool, as should anyone with a skin condition, for their own sake as well as everyone else’s. The skin is an effective protective barrier, but not where it’s broken, as with cuts, ulcers and abrasions. “If you have an ulcer with pus coming out of it, or a terrible skin rash, then five parts per million of chlorine can’t kill that,” says Seto.
“In fact, if you have a rash, the chlorine could worsen it.” If someone else in the pool has a rash, he adds, tell the lifeguard – and if the lifeguard doesn’t do anything, “I’d take my bag and leave.” Viral infections such as warts are also commonly spread at pools, particularly among children. Here, the disinfecting footbath is helpful, but it’s a good idea to wear flip-flops in the changing room and around the side of the pool, rinsing them with water beforehand to make sure they’re free from dirt. While the skin might be totally protective, mucous membranes such as the mouth and eyes aren’t. Hung says ear infections can be contracted either via the ear or the nose, which is linked to the middle ear by the Eustachian tubes. So goggles are a very useful addition to your swimming costume – surprisingly, so is a hairdryer. “The worst thing you can do, which people sometimes do after swimming, is poke your ears with cotton buds,” says
Hung. “They can contain infections. It’s better to blow your ears dry with hot air.” The Leisure and Cultural Services Department (LCSD), which operates Hong Kong’s public pools, also asks swimmers to bring only clean clothing and personal belongings into the pool deck area; to refrain from sharing towels and other personal items; and to make sure their towels and swimsuits are completely clean. If you see anyone wearing anything other than swimwear, talk to whoever’s in charge. Hong Kong’s public pools operate to very high standards, with weekly independent lab tests of the level of free residual chlorine, the pH, the total bacterial count, and the presence of E coli and Vibrio cholerae, the bacteria that can cause cholera. The results of all these tests are even displayed on the LCSD website. In addition, says an LCSD spokesman, “Each public swimming pool is equipped
with a filtration and sterilisation system which continuously filters and disinfects the pool water throughout the opening hours of the pool. Pool staff are required to follow stringent operational procedures to maintain pool cleanliness. “Water tests are carried out on an hourly basis to measure the free residual chlorine level and the pH value, with the aim of ensuring the disinfection capability of the pool water.” The LCSD also monitors the cleanliness of its pools, keeping surface drains clear from stagnant water and dirt, cleaning
Most bacteria come from the gut, and most of them are killed by chlorine DR SETO WING-HONG, BAPTIST HOSPITAL
all pools gutters and sides nightly, and conducting a more thorough cleansing once a week, during which an extra dose of chlorine is added. For private pools, says Seto, “If you see that there’s a lot of dust and dirt in the bottom, talk to the pool owner. Once a pool is dirty with dust, especially organic material, it’s much easier for diseases to spread.” For all private pools, he adds, “It’s important to make sure that it’s licensed by the government. [If so] you can assume, as you can if you go to a public pool, that the conditions are very strict.” So, in Hong Kong at least, you should be safe to swim with confidence. Venture further afield, however, and it’s even more important to take all the right precautions. As Hung points out: “Most of the patients who come to see me with infections resulting from swimming got them when they swam abroad.” life@scmp.com
HITS & MYTHS ................................................ Sasha Gonzales life@scmp.com Is it okay for kids with asthma to play sports? The straight answer: Yes The facts: It’s perfectly fine for asthmatic children to take up sports. In fact, many elite and Olympic athletes are asthmatic, like British marathon runner Paula Radcliffe and American swimmer Amy Van Dyken. According to Dr Amos Lo, a specialist in otorhinolaryngology at Matilda International Hospital, being active may help strengthen an asthmatic child’s breathing muscles. Asthma is an allergic airway disease in which the small airways, called bronchi, become inflamed due to an allergic trigger. When these airways are inflamed, mucous is produced, which blocks the airways. In addition, the mucosal lining of the airways thickens and the muscle around the airways contracts, narrowing the airways further. When an asthmatic person’s airways are constricted like this, they will experience shortness of breath, coughing, wheezing and chest tightness. In severe cases, adds Lo, the airways are so constricted that oxygen is blocked from entering the air sacs (alveoli) in the lungs. This condition is called “silent lung”. Common triggers for asthma attacks include allergens such as dust mites, pollens, weeds, and cat and dog dander; irritants like pollutants; a change in temperature or humidity; and upper respiratory tract infections. Asthma is potentially life threatening and, apart from the clinical symptoms, it can affect the daily life of asthmatics because it can result in a restriction of activities and missed days from school or work. Asthma is not a curable disease. The symptoms simply come and go during the lifetime of an asthma sufferer. The nearest “cure” we have for asthma today is immunotherapy, says Lo.
Photo: Corbis
This involves giving very small amounts of allergen to an asthmatic child over a long period in the hopes of modifying their immune system so that it develops “blocking antibodies” against the allergens. About 11 per cent of children in Hong Kong suffer from asthma. Some may stop having attacks when they’re older, but, generally, the more severe the asthma, the less likely the symptoms will disappear later in life. Exercise may also trigger an asthma attack. But as long as the asthmatic child manages their condition properly, they can do any sport they wish. The key to getting asthma under control: timely and regular medication, and of
About 11 per cent of children in Hong Kong have asthma
course, keeping the living environment free of allergens. That means avoiding soft toys, changing bed linen often, using an air purifier, frequent vacuuming, and replacing carpets and curtains with wood flooring and blinds. If the asthmatic experiences any sign of airway sensitivity while exercising – for example, coughing and wheezing – they should stop what they are doing and seek medical advice immediately, Lo advises. Asthmatic youngsters should also avoid exercising in cold or dry weather, as these conditions may trigger an asthmatic attack. Some of the best sports for asthmatic children are the ones that do not expose them to long periods in cold, dry air. Swimming and biking are ideal. Sports that require short bursts of energy are also acceptable, like rugby, track and field events, and sprinting. Lo says that an asthmatic child can indulge in longdistance running and cycling, soccer, basketball and crosscountry skiing, as long as they have got their condition under control with medication and have gone for a period of time without an attack.