PWTAG 2019 Conference

PWTAG’s annual conference was another near sell-out success. This was the first in the Holywell Conference Centre, on the Loughborough University campus that also hosts our admin hq at Swim England. The hosts did us proud – a fine venue, great technical backup (including a live link to Barcelona) and good food.

Use the links below to download the presentations.

Professor Rachel Chalmers from Swansea’s Crypto Reference Unit and Martin Wood of Pool Sentry

There’s a stark contrast between decent pool water killing E coli in less than a minute and the same chlorine concentration taking over 10 days to kill Cryptosporidium oocysts. Billions can be released in one faecal accident; one is enough to badly infect a bather.

Almost half of cryptosporidiosis outbreaks (outbreak = two or more people ill from the same source) are associated with pools. Leisure pools are the commonest setting – three outbreaks a year over the last eight years.

The key message from PWTAG-funded crypto research in six pools:
• oocysts were found in 20% of pool water samples and 7% of backwash samples
• found when pools were at their busiest
• but the threat can be managed by sticking to PWTAG standards.

There is a bang uptodate Water and Health review article (on the Pool Sentry website). More research is needed (to match that in the drinking water industry), particularly from work on pools themselves. This should further elucidate the impact on Crypto removal of:
• flow rate (seems to be greater than expected)
• filter ripening
• coagulation – increases removal from as low as 20% to as much as 99% – and filter aids (eg hydrous iron aluminium oxide on filter sand, changing electrostatic charges) can triple removal rates
• different filter media and bed depth
• circulation hydraulics – if poor, with dead spots, it could take 16 turnovers to clear the threat, compared with the six specified by PWTAG where circulation and filtration are good.

Professor Cristina Villanueva from the Institute of Global Health

Of the 700 or so disinfection byproducts ever identified, over 100 were found in just two Barcelona pools.

Elite swimmers are over twice as likely to have asthma as other elite athletes (reversible on retirement). Lifeguards are vulnerable to respiratory symptoms
Looking at particular populations:
• pregnant women and children don’t seem to be affected
• babies seem to be affected (though it’s controversial) if the parents are themselves allergic
• adult exposure seems to have some association with certain cancers.

Her own research examined adult swimmers very minutely before and after a 40-minute swim, looking for any evidence of damage at a cellular level. There was some; her conclusion was that it was worth limiting trihalomethanes as much as possible, but that we should balance all this against the very measurable and indisputable health benefits of swimming exercise

And the rest
Chair Janice Calvert brought delegates up-to-date with PWTAG: the newly updated Code of Practice is on the website; the ‘pocket handbook’ is still in development; Poolmark has become more accessible. (Robin Mitchell of PALM Academy spoke separately about this.) Janice also delivered a paper about the significance of chlorine oxidation.

Richy Mariner of the European Chemical Industry Council disentangled some of the complicated strands of biocidal regulations. Chris Hebblewhite of GLL did the same for drowning protection, including some illuminating technical detail about the many different systems – not all of which rely on cameras. What might have seemed light relief, but had lessons for us all, came from one of the best speakers – Emma Pusill, co-author of The Lido Guide. This was mainly about the challenge for volunteers in maintaining (sometimes reopening) the 120 or so lidos that are increasingly popular.

Poolmark awards were presented to the three Abbeycroft Pools in Suffolk and a new certificate holder, Atlantis Leisure in Oban.

Haverhill Leisure Centre

Bury St Edmunds Leisure Centre

Newmarket Leisure Centre

Atlantis Leisure