Hot tubs – healthy or unhealthy choice?
Part 3
Published September 15, 2009
by Frank Rosa
President
Aqua Technical Services Inc.
In previous installments we looked at the history and health threats, here we will look at methodologies to address the issues.
HALOGENS
Chlorine has been used since 1893 to address the health threat in potable water systems, primarily Cholera. Bromine has been touted as the answer – “effective” at high pH and no burning of eyes. However, on inspecting a swimming pool in a High School with Bromine and pH within Health Department specifications, I noted that the white material was actually an infestation of living microscopic worms - as well as some interesting human parasites. Why were children using the swimming pool?
Now that we are armed with information on Halogens, one asks, “Is chlorine use okay?” One would have to answer that C.parvum (Cryptosporidiosis) and Legionella spp. (Legionnaires’ Disease) have shown that not to be the case due to outbreaks associated with potable water supply. Of course, at 5.0 ppm the chlorine could attack the alveoli in the lungs (nose close to the water and those bubbles!), eyes would sting, probably bleach hair and swimming attire – attacking it. To use a halogen one has to anticipate the ORGANIC LOADING of the occupants, 2,3,4,6 in the tub and the amount of organic matter they bring into the tub as well as the “health oils” people add. In a public Hot Tub, motels, hotels, health clubs, Bed/Breakfast establishments, Cruise Ships etc., one must also contend with the filth brought into the tub by the “public”, their state of health (sores, pus) and health habits that defy the imagination.
Are top-rated hotels better? Judge for yourself after reading , about the discovery at The Dorchester, The Langham, The Halkin and The Savoy (£4,000 per night ($8000 USD or 5852 EUR), London, UK, 5-star hotels. Assume nothing just because one is charged a very high room rate, Legionella do not care!
OZONE
The effectiveness of Ozone is superior to that of the Halogens, Ozone is a much stronger oxidizing agent and is not pH dependent. Ozone was the most potent of the biocides tested, with a greater than 99% kill of L. pneumophila occurring during a 5-min exposure at 0.10 to 0.30 micrograms of O.3 per ml (or .1 to .3 ppm) . Concentrations of 0.30 and 0.40 micrograms of free chlorine per ml (0.3-0.4 ppm) killed 99% of the L. pneumophila after 30- and 5-min exposures, respectively. However, one must remember we are talking about tests on lab grown bacteria vs. those naturally occurring, like the difference between a feral and domestic cat.
Of the three Ozone generating methods, the one most used will be the inexpensive Uv unit as it will meet the advertising hype, but not the focused objective. Ozone use in a hot tub is a misapplication of the technology. Last, but but least, Ozone can trigger asthmatic attacks
ULTRAVIOLET LIGHT (Uv)
This is light within the 100-400 nanometers wavelength. There is no residual and only kills that which it can “see”, thus must be installed “full flow” to impact free swimming (planktonic) organisms while unaffecting those within biofilms as well as those fore and aft of the device.
SILVER, COPPER, COPPER/SILVER DEVICES and ZINC (Zn) aka IONIZERS
There may be merit for once through potable Hot Water loops with this technology, but not for Hot Tubs. The objective is to reach and maintain a concentration of the metal ions, 400 Part Per Billion (ppb) (400#/125,000,000 gallons water) of Copper (Cu) and 40 ppb of Silver (Ag), in the water. This is too complicated for the consumer and certainly out of consideration for the commercial Hot Tub using establishment– unless properly engineered. However, the caveat, there is no iron-clad guarantee that Cu, Ag or Zn is effective against ANY or ALL pathogens, just some anecdotal evidence against Legionella, and even that is suspect when one takes metallothione into consideration – chemicals within cells that tie up heavy metals and minimizes their adverse affects on the total cell.
OTHER CHEMICALS
There are, no doubt, formulas being marketed with efficacy claims that are touted as effective against algae and slime growths. Potassium peroxymonosulfate is an excellent oxidizing agent to clean the tub, but no better than Bleach, with a little acid to bring the pH to 7.2, at a fraction of the cost.
MAGNETIC DEVICES
Having done an extensive study on patents and actual devices, I have found them to be worthless, they have failed the test of time – and scientific scrutiny.
FILTRATION
Filtration is a physical extraction technology, offered in specific micron (pore size) ratings. Since the problem with Hot Tubs is bacterial, due to nutrients that are not filterable and heat, filtration is futile.
DRAINING
Some suppliers offer units that are intended to be drained when not in use; Ms. Intille used just such a tub before her near-death experience. Draining, implies opening a valve and walking away – unless printed instructions say otherwise and are followed. Filling a tub on Friday, after it’s been sitting “empty” since Monday will engulf the user in a plethora of organisms that will defy efforts of a Microbiologist to identify. In a drought, area 100-gallons of water is a lot of money.
REALITIES OF BIOFILM
Biofilm is Mother Natures way of providing food and protection to single cell entities. The bacteria that secrete this biofilm do it to “trap” food molecules to sustain life processes. It has “pores”, hills, valleys and clumps of bacterial entities thriving in a symbiotic as well as competitive relationship, and as a hunting ground for bacterial predators, the “protozoans”. The food is the organic molecules deposited by those using the Hot Tub and entering via the cold-water fill line, the addition of “essential oils” may add nutrients. We know that Clams will “clam up” when danger threatens, so will biofilm when its environment is altered by chemicals, to protect the inhabitants therein.
Now look at that which we call “water”, it is not the H2O molecule taught in High School it is a complex structure that flows in a laminar manner. See Fig. 2. If we look at a fast flowing river, i.e., the Niagara River in N.Y.S., we see water flowing at a fast rate in the middle, but slower and much slower as one approaches the shores due to friction, counterflows and a host of factors. The same holds true for water moving inside piping. The closer to the surface of the pipe, the slower the flow and is the environmental niche the biofilm formers favor. When the water flow diminishes, the biofilm will extend farther out to capture additional nutrients. On start-up, a plethora of bacterial entities will be dislodged from within the disturbed biofilm by turbulent flow, leaving behind the short biofilm close to the pipe, and upon the Hot Tub user.
BACTERIAL TESTING
The current least expensive technology involves the use of “DIP SLIDES” and nutrient/dye impregnated paper. Unfortunately, the results obtained are meaningless as the bacteria that grow thereon are not indicators of pathogen presence or absence. Let’s go back to footnote #23, “ It’s been assumed that if the pool water is satisfactory for routine microbiological checks then growth and spread of legionella would also be under control. But we discovered that the legionella bacterium, may be present in high numbers in both privately owned and public facilities even when routine microbiological and safety checks appear satisfactory.”?
Due to the length of time involved, lab cultures for Legionella in a Hot Tube would be futile. However, there is a 30-minute test for Legionella pneumophila SG1 (involved in over 80% of illness in the U.S.A.) that was developed in the UK due to their laws related to the proliferation of this illness. Some dismiss the test as worthless as it will also pick up “dead LpSG1” – forgetting that at one time they were alive to be present. The objective is “NO LpSG1” in the hot tub, living or dead!
Lastly, but certainly not least, one should be cognizant of serious issues of Hot Tub use, as outlined in a health journal. “High temperature bathing in Hot Tubs, spas and whirlpools poses four potential public health concerns: injury/death, disease transmission, possible teratogenic effects, and congestive heart failure or dysrhythmias for individuals with cardiac problems.”
There you have it, after reading this tome, you should have an appreciation of inherent dangers to health. If one feels that benefits outweigh risks, use the devices, but do so cautiously and fully informed. If you do use them and come down with an illness, you should seek medical attention immediately, do not wait; provide the health care provider with all the details. If you use a communal Hot Tub ask about how they address the issues outlined herein, don’t bet that you will receive a satisfactory answer. “The water is filtered”, as you have learned is not a good answer. No one forces you to use the Cruise Ship, Health Club, Hotel, Motel or your neighbors’ Hot Tub, it is your choice, choose wisely. Stay well, be well.
1 Washburn John. JAMA 235: 2205-2207, 1975
2 Melburn, Australia, 1997
3 (Cox GF, Levy ML, Wolf JE Jr Pediatr Dermatol 2 (4): 322-323 (Jul 1985)
4 (Nerurkar LS, West F, May M, Madden DL, Sever JL JAMA 250 (22): 3081-3083 (Dec 9 1983)
5 NY DAILY NEWS, Thursday, July 26, 2007 by Bill Egbert
6 Private communication from Hong Kong
7 Researchers Identify Characteristics of Patients With Legionella Spp. Community-Acquired Pneumonia: Presented at ECCMID-ICC, By Chris Berrie, MUNICH, GERMANY -- April 10, 2007 -
8 Relaxing spa, deadly menace, Nurse on a mission after barely surviving Legionnaire’s disease, by Virginia Hennessey, Herald Salinas Bureau
9 Legionnaires’ bug hit 115 people at spa club Jul 13 2007, by Graeme Whitfield, The Journal (UK)
10 Personal communication relating to CODES
11 FOURTH VICTIM OF LEGIONNAIRES’ BUG, 08:50 - 07 July 2007, The Press and Journal, North Scotland, UK
12 MEDIA RELEASE, USE: Immediate, ISSUE DATE: 27/07/07, NHS Highland
13 Spa pools a cause of legionnaires’ disease, UK, News, Article Date: 14 Sep 2004 http://www.hpaconference.org.uk
14 http://en.wikipedia.org/wiki/Antibiotic_resistance
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