Research evidence that chlorinated swimming pools can damage children’s lungs is being played down by British water-treatment specialists. But they are concerned that many school pool operators may be putting children’s lives at risk by failing to follow guidelines about design, hygiene and use of disinfectants.

Belgian researchers from the Catholic University of Louvain who tested eight to 12-year-olds believe they have found a correlation between lung damage and weekly swims at indoor pools using chlorine (TES, October 26). However, UK experts say there is insubstantial proof of long-term negative effects from the disinfectant.

“These conclusions fly in the face of everything else that we know,” says Ralph Riley, chairman of the Pool Water Treatment Advisory Group and chief executive of the Institute of Sport and Recreation Management. Riley also disputes the wisdom of using bromine instead of chlorine, as suggested by the Louvain team.

“I see no reason to switch from chlorine to bromine, which can have its own problems and has been known to cause skin rashes,” he says. “Many pool operators in the UK would not touch bromine with a barge-pole.”

Despite his belief that chlorine is not directly linked to asthma or other long-term health problems, Riley does accept that it can be harmful when used without proper instruction or in a poorly engineered pool, especially if basic hygiene rules are not followed.

“If people do not wash before entering the pool they carry pollutants on them in their sweat and urine,” he explains. “These pollutants can mix with chlorine to produce chloramines, which can irritate the upper respiratory passages, causing red eyes and irritation of the nasal passages. Good pool management will control this.”

Compared with European countries, Britain is not known for its stringent hygiene habits in pools, which is why we can often smell “chlorine” - actually the nitrogen trichloride, created by this mix. It is this gas, coupled with poor ventilation, that the Belgian researchers blame for lung damage in children.

Riley has concerns about the 2,300 school pools in the UK, as few are members of ISRM, which has up-to-date materials and training. “We are very concerned about school pools,” he says. “Children have died because the engineering has been wrong.” In 1999 an eight-year-old boy died after being sucked into a pool water outlet at Mercenfield primary, Leicestershire. The county council was fined pound;15,000 for failing to ensure his safety.

“Schools cannot afford not to join ISRM and follow guidelines, because the chances of getting it wrong are very high,” Riley says.

PWTAG encourages operators to use minimal amounts of chlorine, which can cause coughing and other short-term respiratory problems if used in large doses. But school caretakers often pour chlorine straight into the pool by hand, unmeasured. This can lead to under or over-dosing.

Chlorine kills infections instantly, but it can be supplemented by using ultra-violet radiation or ozone. These zap bacteria before they enter the pool, so less disinfectant is needed.

If the chlorine levels exceed 1.5 to 2 parts per million - the recommended limit for a pool not using ultra-violet or ozone - the pool hall atmosphere may deteriorate. But water treatment specialists say they have detected chlorine levels of up to 4ppm in some schools. Many school pools are likely to have inadequate design and engineering, making it difficult to reduce levels.

Despite these problems, the benefits of swimming remain undisputed. Noel Winter, of the Amateur Swimming Association, says asthma sufferers in particular can benefit from the sport. “Swimming in indoor pools can actually help people with asthma, because of the warm, damp atmosphere,” he says.

Pool Guidelines: Managing Health and Safety in Swimming Pools (1999), by the Health and Safety Commission and Sport England (HSG179), ISDN 0717613887. Available from Sport England Publications, POBox 255, Wetherby LS23 7LZ. Price pound;10.50. Swimming Pool Water, by PWTAG, ISDN 0951700766. From Greenhouse Publications, Holly Lodge, Botesdale, Diss, Norfolk IP22 1BZ, pound;35 inc pamp;p