Hot tubs, their planning, design and installation getting it right

Transcription

1 Hot tubs, their planning, design and installation getting it right John V Lee BSc, PhD, FRSPH, FWMSoc, FPWTAG PWTAG Director &Technical Adviser Leegionella Ltd. Edgemoor Cottage, Rockford, Ringwood, BH24 3NA johnvlee@leegionella.co.uk

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4 UK drowning statistics for 2010! Swimming Pool News 30 January 2016! Twenty-four fatalities were the result of incidents in baths (including jacuzzis or hot-tubs), six in swimming pools.!"

5 Electrocution! Hot tubs sold in Derby gave people shocks and left them at risk of drowning! By Derby Telegraph!! Posted: January 11, 2016.! A BUSINESSMAN has been fined 12,000 for selling faulty hot tubs he knew were unsafe and that gave people electric shocks.! Ian Crilly, 50, who runs Derby firm Midland Hot Tub Hire, sold one victim's family a spa that shocked her, her mother and her dog.! He sold another to a second customer which tripped her home's electrics, Derby magistrates heard. #"

6 Just pop down to the garden centre/ DIY store to look at some spas! JTF Wholesale fined 1m for health and safety breaches! 21 cases including 2 deaths Legionnaires' disease! outbreak in the summer of 2012 traced back to a display hot tub at the company's Fenton store in Stoke-on-Trent.

7 Spa pool / hot tub type equipment for hire & inappropriate uses $"

8 Hot tub hazards Physical entrapment, drowning, slips and trips, overheating, electrocution Chemical chlorine releases, disinfection by-products, bromine rash, potassium peroxymonosulfate (PPMS) allergy Infection! Legionnellosis (legionnaires disease, Pontiac fever)! Pseudomonas aeruginosa infections of skin, urinary tract, ears and eyes! Mycobacterial infections! Amoebal keratitis Misuse! Spa pools/hot tubs as birthing pools! Overloading of domestic hot tubs for business use %"

9 Hot tub water related infections: modes of contraction Common in hot tubs! Contact Pseudomonas aeruginosa, Mycobacterium spp.! Aerosol (inhalation) Legionella, Mycobacterium Unusual in hot tubs (users shouldn t immerse their head!)! Ingestion ( usually faecal oral pathogens causing gastroenteritis [vomiting and diarrhoea])! Aspiration (water going down the wrong way )

10 Origins of water borne infectious agents (pathogens)! Exogenous organisms not naturally occurring in water animal / human origin! Faecal - E. coli O157, Salmonella, Shigella, Enteroviruses (polio), Norovirus, Cryptosporidium, Giardia! Non-faecal Staph. aureus, papilloma virus etc. Indigenous organisms that grow in water naturally! Some may survive mains water treatment! Grow in biofilms! Increasingly important as sources of infection! Legionella pneumophila & other Legionella spp.; Pseudomonas aeruginosa; Mycobacteria

11 Legionellosis = infection caused by Legionella Severest - legionnaires disease! pneumonia:! symptoms: cough - usually dry, 75%; fevers 70%; confusion, 45%; new sputum, 45%; bad headache, 32%; diarrhoea & vomiting ~30%! up to 40% die (European average ~10%)! low attack rate infects less than 5% of those exposed;! susceptibility: increases with age; 3 males : 1 female; underlying disease; immunosuppression! incubation (time from exposure to first symptoms) : 2 10 days but sometimes 16 or even up to 21 days Mild - Pontiac / Lochgoilhead fever! high attack rate: affects over 95% of exposed and all ages equally! influenza like illness: no deaths! incubation: hours! Asymptomatic (healthy without symptoms)! (serological evidence) of exposure to infection! HOT TUBS / SPA POOLS ARE THE THIRD MOST COMMON CAUSE OF LEGIONNAIRES DISEASE

12 Pseudomonas aeruginosa folliculitis! Skin infection caused by Pseudomonas aeruginosa in badly managed pools! Red elevated papules, some of which may be pus-filled! Appears hours after exposure: itches, but usually resolves spontaneously.! Outbreaks first recognised in the 1970 s in USA in spa-pools with low Cl 2! Worldwide problem! Children under 10 more at risk - in one outbreak!90% attack rate in children cf.!50% in adults! HOT TUBS & SPA POOLS PROBABLY THE MOST COMMON CAUSE OF PSEUDOMONAS AERUGINOSA FOLLICULITIS

13 Mycobacteria spp. and Hot tub lung "Hot tub lung" is a fairly rare infection or allergic reaction of the lungs (allergic pneumonitis) due to inhaling Mycobacterium spp. from a hot tub.! Mycobacterium avium (Sugita et al 2000)! 3/5 in family associated with home spa pool! Non-tuberculous Mycobacteria (NTM) in 10 immunocompomised patients (Khoor et al 2001)! All associated with the use of a hot tub! NTM in 5 patients (Mangione et al 2001)! Isolated from a family of 5 and 2 tubs England! Herts case associated with domestic hot tub! Essex 2007! 2 cases associated with domestic hot tub! Several different Mycobacterium species isolated from tub even after 2 successive hyperchlorinations

14 Acanthamoeba keratitis &!"

15 Growth in biofilms! Aquatic micro-organisms prefer to grow as biofilms on surfaces! Nutritional advantage! Protective Can take up to 1000 x greater exposure to a given biocide concentration to kill an organism in a biofilm as it would to kill the same organism in water Organisms in biofilm are in a different, more resistant physiological state! Legionella pneumophila - facultative (?) intracellular pathogen! Associated with 14 species of amoebae, 2 species of ciliated protozoa, and one species of slime mold! Protozoa can protect Legionella! Can survive inside amoebal cysts treated with 50ppm chlorine overnight! Cysts also can protect against drying and heat!"#$%&'(")*+'$,-.$(,/*'()*+,*-".',/"01*+)"2(.+&,3%**

16 Growth on different plumbing materials relative to glass (=1) Growth relative to glass 10.0 Heterotrophs Legionella! Legionella and supporting flora were grown in continuous culture model systems.! Counts are expressed as a ratio relative to the counts on glass (=1)! e.g. there was approximately 10 X the growth of aerobic heterotrophs on cpvc as there was on glass. 1.0 Copper Glass Polybut Polyprop Polyeth upvc cpvc EPDM Latex 0.1 Conclusion: higher flexibility of plastic generally correlates with increased support for growth &0"

17 Biofilm inside flexible hose of hot tub that caused folliculitis 1+2(('(3"*4*+,56("7' /"6)"9'6:47" '(;'-*"2"<*='94*"+6((*+,65"9>"?'(-"

18 Factors Encouraging Colonisation (biofilm Formation) in Artificial Water Systems! Nutrients for microbial growth! Assimilable organic carbon (AOC) in supply water! Dirt! Construction materials (natural > synthetic > steel > copper)! Difficult to clean (poor design)! Stagnation! Tanks too large, pressure vessels, dead / blind ends, low flow! High surface to volume ratio! Physico-chemical conditions! Temperature 30 C - 45 C, scale & corrosion

19 A single modern hot tub may contain as much as 75 metres of flexible and fixed pipes with a total surface area of 5.5m 2 Air and water circulation systems give a large surface area for biofilm growth

20 Why are spa pools & hot tubs a problem?! Elevated temperature C- encourages growth of bacteria including Pseudomonas aeruginosa, Mycobacterium and Legionella! High organic load - nutrients from bathers e.g. dead skin, sweat and other body secretions, bath oils, body lotions soaps etc. washed off by air and water jets! High bather density and water reused! Bubbling creates aerosol at head level! High organic load + aeration + temperature + agitation creates a challenging problem for effective disinfection! High surface to volume ratio! Lots of inaccessible and difficult to clean components

21 Selection of type of spa pool and site Likely bather load! You will need a commercial overflow spa pool if :! All day use by several bathers e.g. leisure centre, health club! Serving more than one flat/room/chalet/caravan! A hot tub can be used if! use is similar to that of a single household i.e. only a few individuals will use it once or twice a day for a limited time e.g. one per chalet/caravan/ room etc C&"

22 Siting! Near suitable safe power supply complying with BS 7671:2018 (IET Wiring Regulations)! Water Supply potable quality! complying with Water Quality (Water Supply) Regulations 1999 or! Private Water Supply Regulations 2016! Permanently plumbed water supply via nearby tap with non return valve compliant with Water Quality (Water Fittings) Regulations close enough so that only a short length of hose that can be readily disinfected is required to fill it! Suitable foundations to provide support to prevent flexing of the shell and allow ease of drainage! Other safety issues! Preventing access to young children?! Ventilation if indoors CC"

23 Additional risk factors if outside!not subject to contamination from above e.g. under gutters or other structures permitting roosting birds, under trees etc.!dust, leaves, grass, soil, bird droppings

24 Construction - general! All fittings must comply with the Water Supply (Water Fittings) Regulations 1999 or Scottish equivalent! Materials should not support microbial growth! All non-metalic materials must comply with BS6920 NB this is not the same as food grade compatibility! Surfaces should be smooth and free of defects that would support microbial growth! General principle! Everything should be easy to clean which also means it needs to be as accessible as possible and easily removable to facilitate cleaning C!"

25 Pipework! design to be easily cleaned! minimise length of pipe runs to avoid deadlegs and minimise surface area for growth! materials compliant with BS6920! no internal corrugations no flexible internally corrugated pipe C#"

26 Jets! Booster jets should be designed to! discourage biofilm formation! Facilitate inspection, cleaning, and treatment programmes! Prevent areas where water can remain stagnant! facilitate use of biodspersant cleaners and biocides active against biofilms such as chlorine dioxide! Air blower systems! Air blower systems with a series of air holes or injector nozzles in the floor and seats can be very difficult to clean and disinfect! Pipework should be designed to be demountable and accessible for inspection cleaning and disinfection! PWTAG does not recommend them C0"

27 Air system often impossible to clean and disinfect

28 Entrapment C%"

29 Outlet and inlet safety preventing injury and entrapment! Covers and grilles should be strong and secure enough to withstand impact and vandalism.! Gaps in apertures must be no more than 8mm to prevent trapping of toes and fingers! Any suction pipe capable of being connected to the full suction of any pump should be connected to at least two separate outlets strategically spaced apart and the water velocity through them should be no more than 0.5m/s.! A single bather should not be able to block all the inlets to one suction pipe! All outlets should pass the hair entrapment test in BSEN ! inlet water speed should! not exceed 4m/s if for circulation only or! Not exceed 15m/s for massage jets CD"

30 Water treatment! Cartridge filter! Easy removal for regular (frequent) inspection and cleaning! Filters numbered and dedicated to a single hot tub where there are several on a site! In line disinfectant feeder for use with chlorine or bromine tablets Heating! Usually operate at C! Heater should be sized to ensure the rate of temperature rise not cause damage to the shell or any tiling but should be capable of heating the pool within a suitable timeframe EF"

31 Leak testing can contaminate the tub before it leaves the factory!! Manufacturers should take suitable precautions to prevent the water used for leak testing becoming contaminated and contaminating the hot tub! Use potable quality water! Keep it cool! Keep it clean! Add biocide e.g chlorine at least 5mg/l at ph ! Drain the hot tub and pipework as completely as possible! Possibly use air to blow out residual water and dry the pipe-work E&"

32 Commissioning! Must be carried out by competent people in a logical defined manner following the manufacturers instructions! Adequate time and resources must be allocated! A new unused hot tub can still contain significant amounts of nutrients for microbial growth from:! New synthetics, particularly flexible ones, leaching chemicals into the water! Dirt entering during manufacture, in transit, in storage and during installation! Any residual water left from leak testing in the factory can become heavily colonised in transit IT IS ESSENTIAL COMMISSIONING INCLUDES CLEANING AND DISINFECTION OF THE WHOLE SYSTEM EC"

33 Commissioning should include! Disinfection, typically with 50mg/l chlorine for 1 hour at ph ~7.0! Evidence all appropriate regulatory and safety standards have been met! water supply, water fittings, electrical wiring and building regulations etc.! Comprehensive functional water test to ensure the hot tub system is operating correctly! Chemical and bacteriological analysis of the water to ensure operating parameters are being achieved and maintained! Procedure and results should be fully documented! ONCE COMMISSIONED TREAT THE HOT TUB AS IF IN NORMAL USE EE"

34 Thank You Now all you have to do is maintain and operate it properly! E!"

35 Hot tubs on display can also cause legionnaires' disease Westfriese Flora, Flower show, Bovenskarpel, The Netherlands 1999! Overall 226 cases with 28 deaths! 77,061 visitors! 281 water samples! Risk of infection increased with time spent near spa! 2 hot tubs on display positive for patient type! 1 misting machine positive for other type Trade fair in Kapellen, Belgium, 1999! 80 persons who developed clinical symptoms, 13 had positive urinary tests 4 deaths.! Over visitors attended the fair