Indoor Air Quality in Swimming Pools

Indoor Air Quality in Swimming Pools

Freestyle Breathing Or A Risk To Our Health?

Swim lessons are a parenting duty, but Sophie’s research has given her reason to hold her breath… 

This is the second episode of  ‘Sophie’s Travels’  a story about places where, surprisingly, air quality may not be as good as expected and brings us on journey in pursuit of healthy air while balancing the science with everyday life.

By Lifestyle Medical Author Dr. Anna O’ Donovan


It’s Saturday morning and in Sophie’s house that means swim lessons after her indulgent ‘me time’ in the gym. To be honest she would rather, to steal a favorite phrase of her husbands, stick pins in her eyes, but she admits that swimming is an essential life skill and her kids have to learn. Just until you can easily swim a few lengths, she tells them for the millionth time when they moan and groan about having to peel themselves off their tablets and out of jammies. Swimsuits refuse to be found and laundry baskets are upended in frustration, their contents seeming to bury any gym high Sophie was enjoying. A few final roars and shouts and they are all out the door, dragging bags after them like balls and chains.

It’s a bleak winter day and the kids compare their misty breaths in the frigid air of the car park. Sophie can’t help but notice that Sean’s plume is far smaller than Tara’s and she delves a hand into the depths of her bag to reassure herself that she has packed his inhaler. Her palm closes around the little device as it has hundreds of times before. Since his asthma attack after a swimming lesson last month, she has become paranoid about forgetting it. Certain at the time that it had been the exercise that had triggered his attack, she hadn’t given it a second thought, but now, newly armed with a wealth of information, she suspects it may have been the poor air quality. 


The changing rooms are more like a sauna than some actual saunas Sophie has been in. Sean is next door in the men’s locker room and a frisson of anxiety runs through her knowing that the dramatic change in temperature is also a trigger for an asthmatic event. They unzip coats and rip off hats before they feel faint. Pretending not to fight other families for space on the wooden benches but doing so all the same, she successfully elbows a few inches of no man’s land and piles up their belongings. She picks Tara’s clothes off the wet floor, biting her tongue to prevent herself berating the child as she knows in an hour’s time they’ll be sweating over pulling those now soaking leggings up Tara’s damp legs. It’s almost impossible to dry off in this muggy atmosphere and with no dehumidification system, the mold she spots on the tiled wall will spread unfettered. She eyes them warily knowing that that mold spores can cause asthma and can trigger an attack.

The ripe smell of chlorine that is forever associated with the echoey shrieks and hollers, shrill whistles and incessant splashing of her own childhood swim lessons envelopes her when she steps into the swim area. Though today she knows that it isn’t actually chlorine that she is smelling but a substance called chloramine. Chloramine is a gas implicated in causing skin irritation, rashes, burning throat and respiratory distress. It is responsible for what regular swimmers call ‘swimmers cough’. This pool most certainly does not pass the ‘sniff test’ recommended by the Cleveland Clinic guidelines she read about. Apparently, the level of chloramine is safe when she cannot smell it.

Sean is shimmying his way down the wet tiles towards her, arms crossed and hands clamped in his armpits, his new posture designed, she presumes, to cover his extraordinarily skinny frame newly sprouted in a spurt of pubertal cruelty. Her heart softens. Children have ended up seriously ill -even in intensive care-after spending extended time in pools where the chloramine levels were high. And this pool fills many of the criteria needed to create high levels: the room is low-ceilinged, it is dense with people, it is poorly ventilated. 

Indoor Air Quality in Swimming Pool by Dr. Anna O'Donovan Allergy Standards

Indoor Air Quality in Swimming Pool by Dr. Anna O’Donovan Allergy Standards

“Go on, join your group” she says with an encouraging smile, though of course he pretends not to see her and slides into the pool, happy to be with his peers and forgetting any self-consciousness. Today, they are learning to breath correctly, to smoothly inhale and fill their lungs to capacity to fuel themselves for their next strokes. It’s horrible to think that a couple of inches above the water, just where her son is to suck in a mouthful of air, is exactly where the toxic chloramine sits. If the managers here have been over generous when adding the chlorine intended to sterilize the pool, it will mix with organic material, like the pee that all these children have no doubt joyfully released, to create this harmful gas. Chlorine concentration drops quickly so in order to maintain levels and even thinking they are ‘erring on the side of safety’ to kill all bacteria it can be common practice to over chlorinate.

Sophie was unrelenting this morning when her kids begged not to have to shower before swimming. She urged them to use soap too, knowing that this reduces the amount of organic material available to mix with the chlorine. The kids, like her, had always assumed that to wash before swimming was simply a courtesy to other pool users to help keep the pool clean. They were genuinely interested and much more willing to cooperate once she made clear to them that it was actually to minimize toxic gases. Wagging a stern finger at them and trying to suppress a smile, she had warned them not to pee in the pool. “But Mum, Michael Phelps pees in the pool all the time,” retorted Sean, who had become hero struck after the last Olympic Games. According to her son, the famous swimmer had said so in an interview, claiming that elite athletes, practically sewn into their suits, found it too much trouble to undress to urinate and regularly ‘let fly’ in the pool. Sophie is grateful at least that no elite athletes train in her pool. She did learn that it is these elite athletes, who spend so much time in pools, who suffer most from lung problems and a much higher percentage of them have asthma than the general population. At least when these athletes finish their career, their asthma thankfully tends to disappear.

Tara needs help with her swimming hat, a mandatory requirement in this pool, and Sophie’s tucks in the tendrils of long hair, ensuring no escapees – another tip learned from her research. Hair, along with skin cells and urine all contribute to the organic matter potentially mixing with chlorine. It was satisfying to discover that Sophie herself can help improve the air quality at her pool simply by modifying some behaviors: shower with soap, no peeing in the pool, remind her children often to get out of the pool to use the restrooms, wear effective swim hats. She has friends with kids still in diapers and reminds herself to mention to them to use special swim diapers at the pool.

Despite her reluctance earlier, Tara, always the water baby, loves swimming. The water splashes and churns as she and the younger kids kick and play chaotically in the shallow end. This is perfect aerobic exercise for her kids – the kind they get without even noticing. Sophie is happy to leave her with her teacher and seek relative solace in the adult only lanes. 

She is aware that this pool is overcrowded, that all that churning of the water is kicking up more toxic gas and too much organic material is being washed into the water. It is clear that the chloramine smell is too strong to be within safe levels, but her alternatives are not an option. An outdoor pool is not a reasonable alternative in winter, there are no salt-water pools in the area and a quick internet search informed her that no pool in her entire city uses the safer, but more expensive, bromine for sterilization. She can hardly ask the pool management to install the expensive specialized HVAC systems required to pump out the chloramine tainted air, though they might consider it if they knew that chloramine could corrode their building to the point of being condemned as what happened to one building in South Carolina!

For the moment, Sophie is content making her small adjustments to improve the air. It occurs to her that a school project might be a clever way to teach kids that showering before a swim and refraining from peeing in the pool are not just good manners but are an essential contribution to cleaner air. She gathers her shivering kids at the pool’s exit, all wet hair and damp clothes, their spent bodies and growling bellies yearning for some Saturday brunch pancakes. 


The next article in the series will focus on air quality on cruise ships and the very surprising findings on board…..                                         

About Dr. Anna O’Donovan – Medical & Lifestyle Author

Dr Anna O'Donovan

Dr Anna O’Donovan

Anna is a mum of three children, one with allergies, and she suffers from allergies and asthma herself. She is a qualified doctor and worked as a General Practitioner and as a dentist for a number of years. She is also an award winning author.


swimming pool, chlorine, chloramine, mould, air quality, lungs, indoor air quality, pollution, asthma, allergy, allergy insights

Further Reading

Br J Sports Med. 2008 Apr;42(4):244-8; discussion 248-9. Epub 2007 Aug 21. Airway inflammation in the elite athlete and type of sport. Belda J(1), Ricart S, Casan P, Giner J, Bellido-Casado J, Torrejon M.

Int Arch Occup Environ Health.2006 Oct;80(1):32-9. Epub 2006 Apr 4. The determinants of prevalence of health complaints among young competitive swimmersLévesque B1,Duchesne JF, Gringas S, Lavoie R,Prud’Homme D,Bernard E,Boulet LP,Ernst P. SOURCE: International Journal of Environmental Health Research, online June 25, 2017.

Environ Health Perspect.2009 Apr;117(4):500-7. doi: 10.1289/ehp.11513. Epub 2008 Sep 30. Childhood asthma and environmental exposures at swimming pools: state of the science and research recommendations. Weisel CP1, Richardson SDNemery BAggazzotti GBaraldi EBlatchley ER 3rdBlount BCCarlsen KHEggleston PAFrimmel FHGoodman MGordon GGrinshpun SAHeederik DKogevinas MLaKind JSNieuwenhuijsen MJPiper FCSattar SA

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By |2020-10-13T09:18:20+00:0020 December 2018|Comments Off on Indoor Air Quality in Swimming Pools