The third International Pool and Spa Conference, organised by the Pool Water Treatment Advisory Group, attracted almost 200 delegates to London in March. They enjoyed three days of top-quality papers from world experts – academics, public health professionals, consultants and others. As well as addressing urgent issues of the day –  like Cryptosporidium and asthma – there were many technical papers on disinfection byproducts, management etc, as well as a look into the future of international cooperation in research and standards.

Delegates came from Austria, Bahrain, Belgium, Cyprus, Czech Republic, Denmark, France, Germany, Greece, Holland  Hong Kong, Hungary, Ireland, Israel, Italy, Malaysia, Portugal, Slovakia, Slovenia, Spain, Sweden, UK and US. The first of these biennial conferences was in Budapest, the second Munich. The Royal College of Physicians’ hq in Regent’s Park was the venue this time.

The conference was divided into six sections – Infections, ­Water treatment, Risk management, Technical management of hygiene, Health impact of disinfection byproducts and Open forum. There were 35 papers in all, representing the work of over 100 workers. This account can inevitably give only a flavour of the conference.

Cryptosporidium, the number one cause of gastrointestinal illness from water, inevitably featured. A contribution from the US Centers for Disease Control and Prevention underlined the importance of acting quickly when cases appear, and even anticipating problems in the outbreak season by taking preventive measures: warning the public, stepping up water treatment etc. Although it was clear from other conference papers that Cryptosporidium can readily be found in a proportion of pools (and that so-called swim diapers do not keep it out of the pool!) work done on behalf of PWTAG reinforces confidence that it can be removed by good filtration and coagulation. Infection problems from mycobacteria and fungi in pools were also discussed.

There is a lot of interest around the world in both improving conventional water treatment  and finding an alternative to chlorine disinfection. This conference seemed to encourage the first aspiration but not the second. Speakers from Germany and Denmark spoke of the application of  membrane filtration to pools. There may be a financial price to pay –upfront and in running costs – but some delegates at least see membranes replacing sand eventually. As for alternatives to chlorine, Dutch water scientists reported on their ‘multi criteria analysis’ of 12 different disinfection systems. Some – copper/silver ions for example – fell at the first hurdle: they didn’t pass the microbiological effectiveness test. Taking every available factor into account, the best systems all involved sodium hyochlorite, mostly with UV or ozone. This section ended with insider descriptions from the Olympic Delivery Authority and the water treatment designers, of the challenges involved in building the aquatic centre for 2012.

Risk management was the theme for an interesting series of papers. The database of pool performance results that Hungarian authorities are setting up was too big brother for some in the audience. But a systematic approach to bathing load pioneeered by some Dutch researchers was intriguing. Using a controlled shower cabin they were able to measure the effects of dirty bodies on the pollution load entering the pool – and the beneficial effects of showering, The dirtiest would-be bathers could carry 26 times as much pollution into the water as the cleanest; on the positive side, showering removed about 80%  of the pollution. (Interestingly, this echoed work done less formally by PWTAG over ten years ago.) Representatives of the Federation of Tour Operators described how they co-operated with the Spanish government after a series of major cryptosporidiosis outbreaks associated with hotel pools in 2000 and 2002. There was a clear need for some unified guidance on how to operate the pools, especially in the event of an apparent outbreak. As it happens, and apparently by coincidence, there have been no major outbreaks since, to test the new guidelines.

The section of the conference on technical management opened with a brave attempt from  Gordon Nichols of the UK Health Protection Agency to start assesssing quantitatively the disease burden from swimming. This difficult work is still some way short of suggesting intervention strategies. An HPA colleague spoke of the more immediate problems raised by the proliferation of interactive water features. Unless they include decent water treatment, there is a very real infection risk.

Asthma was the cloud hanging over the section of the conference that dealt with disinfection byproducts. Two separate papers from CREAL in Barcelona suggested first, that lung damage was by no means as clear-cut as Belgian studies had suggested. Second,  a survey of over 3,000 school-age children could find no association between swimming and asthma. On the other hand, toxicological work from Germany did suggest  a link. And there were interesting data from an Italian study comparing the lifetime exposure to disinfection byproducts in competitive, frequent and occasional swimmers.

The conference closed with a challenging open forum looking at how to build on the common purpose so manifest in such a conference. It was agreed that there was a need to share knowledge and develop some common parameters that would be applied to the necessary research. There were many volunteers from all the many countries represented, to make up an initially internet-based forum for this work.

The conference also marked the long-awaited launch of the new edition of PWTAG`s definitive book of guidelines, Swimming Pool Water: treatment and quality standards for pools and spas. Each delegate was given a  free copy.  For the rest, £45 seemsvery  reasonable for 200 pages of updated, in some cases new material covering a subject so critical to healthy swimming. There are new chapters on swimming pool basics, dealing with outbreaks, spas, leisure pools, hydrotherapy pools, outdoor and paddling pools, domestic pools and interactive water features.

The proceedings of the 2009 conference are now freely available here.

The 2011 conference will be in Portugal. Details here