Articles

To Floc or not to Floc? That is the question

My insincere apologies to William  Shakespeare for the following:

To floc, or not to floc: that is the question:

Whether ’tis nobler in the mind to suffer

The slings and arrows of Crypto, Giardia and Acanthamoeba

Or by floccin, reduce, or at least oppose them.

Definition: Flocculants work by binding with minute particles in water that cause cloudiness, making them large enough to be caught in the filtration system and leaving the water clear
Now, in this article, I’m not talking about pools, I am talking about hot tubs or spas.

I refuse to call them pools as pools are something that we swim in and baths are something we lie and relax in. Two completely different functions and yet the gurus in our industry have ‘flocced’ them together under the singular heading of ‘pools’. There are so many differences in the operation of swimming pools and spa baths in both water capacity, type of use and ratio of users to water volume, temperature, disinfectant and pH levels plus, in my opinion ‘floccin’, that we should clearly differentiate between the two.

Gardia                                                           Cryprosporidium                                   Acanthamoeba

It has been argued that there has never been a spa bath that has had a proven association with the above, but I feel that most cases are not recognised or even are commonly misdiagnosed by health professionals.
NOIDs is the Notifications Of Infectious Diseases and is published weekly giving statistics of disease outbreaks in the UK. I followed this religiously until I became aware of a Crypto outbreak that affected a large number of people yet did not warrant an entry into the NOIDs statistics at that time.

Registered Medical Practioner in England and Wales have a statutory duty to notify a Proper Officer of the local authority, often the CCDC (Consultant in Communicable Disease Control), of suspected cases and although Legionnaires disease and Leprosy are notifiable, Cryptosporidiosis and Giardiasis, strangely are not and only voluntarily. Out of interest, week 49 showed eight cases of Giardiasis and seven of Cryptosporidiosis.

Of further interest, there were 4,655 cases of Tuberculosis in the UK 2018, well that were notified anyway and 30950 of Scarlet fever so far this year. So following the assertion that there has never been an outbreak associated with a spa bath I would point out : haven’t we all heard that Qantas, the Australian airline, has never suffered a fatal accident? This myth, perpetuated far and wide is something that Qantas doesn’t exactly rush to dispel. However in truth, records indicate that Qantas have had a number of accidents.
In pools and baths, we rely on flocculation to gather up microscopic particles and adhere them to one another in a process similar to how we make snowballs and no, I don’t mean Advocaat and lemonade!
Cryptosporidium grows to approximately six microns and Giardia fifteen.
To appreciate size, a human hair has a diameter of between 60 and 90 microns, a white blood cell is about 12 microns and the limit of human visibility is approximately 40 microns. Both of the above and especially Crypto due to its smaller size, can pass through many filter medias and being unaffected by normal levels of disinfectant, can live for prolonged periods in pools or spa baths, possibly until ingested by a user.

The dangerous illnesses from these can be caught by swallowing pool (or bath) water containing Crypto and Giardia and the World Health Organisation (WHO) research indicated that the average water intake by adult men was 22 ml and this was higher than that by women (12 ml). Whilst their research was about pools, I believe it could equally apply to both spa baths and hot tubs.

Ultra Violet will control Crypto and/or Giardia by disrupting their DNA and RNA and in this manner limit them. I have in the past discussed the need for flocculation in spa baths with two of our industry’s most eminent personnel and both of them stated that there was not a need for flocculation as nobody ever put their face in the water in a spa bath. I personally know people who are teaching their children to swim in spa baths and hot tubs and the first thing they tell their children is ‘put your face in the water’ I have observed both children and adults ‘water spouting ‘ in spas and hot tubs and to the Gurus who say; ‘ nobody should put their faces in the water in a spa bath’ is similar to the other advice given that ‘people should shower thoroughly before going in a pool or spa’ in as much as people will pass through a shower at the speed of an email transmission failing to take a blind bit of notice of either piece of good but ineffectual advice.

If there is a discharge of liquid faecal matter or even a flatulent release from a user who is suffering from these ailments, there are likely to be millions of oocysts released into the water and if a bather swallow even 5mls (a tea spoonful) of that water, they may well have swallowed an infectious dose. Further advice advocate not using aquatic facilities if suffering with gastro enteritis problems, I have witnessed to be routinely disregarded. However, reporting of this problem is likely to be an underestimate because cryptosporidiosis outbreaks may not be identified or reported (Ryan et al. 2017).

Information re: Giardia cysts are approximately 5–15 Microns (um) in diameter.
Viable cysts that are ingested by humans have an incubation period of about 7–12 days. The resulting gastroenteritis is characterised by diarrhoea with accompanying abdominal cramps. The illness commonly lasts for about 7–10 days but dependent on the sufferer’s general health can be even longer.
Cryptosporidium oocysts are 4–6
μm in diameter and are even more resistant to chlorine than Giardia cysts.
If viable oocysts are ingested, there is an incubation period of 4–9 days before symptoms appear. The illness lasts about 10–14 days, days but dependent on the sufferer’s health can be even longer, with symptoms typically including diarrhoea, flatulence, vomiting, nausea and abdominal cramps. Some lagers can produce a similar reaction with me. In patients who are immuno
compromised, such as those with HIV infection , cancer and transplant patients or those taking certain immune systemsuppressing drugs, cryptosporidiosis is generally chronic and can last long enough to be life threatening (Petersen, 1992).

MacKenzie et al and the CDC (The USA Centers for Disease Control and Prevention) showed that the Milwaukee outbreak in 2003 was caused by Cryptosporidium oocysts that passed through the filtration system of one of the city’s supply watertreatment plants, arising from a sewage treatment plant’s outlet two miles upstream in Lake Michigan. Research indicated that more than 400,000 people of the 1,600,000 people supplied, displayed classic symptoms with in excess of 100 deaths mainly from immunocompromised groups.

The Human pathogenic species of Acanthamoeba are approximately 15 to 35 microns in size and can cause Acanthamoeba keratitis that affects contact lens wearers who are identified as at most at risk from the infection and account for approximately 90% of reported case.
Although these cysts are resistant to chlorineand brominebased disinfectants, they can be removed by enhanced filtration and this is why my employers Studies In Work when carrying out a risk assessment recognise there is a hazard (something with the ability to cause harm) and then strongly advocate the use of a flocculent not only in pools but also in Spa baths and hot tubs. This increases our level of protection against these hazards and offers some protection in law to both the operator and Studies In Work.
At the end of the day it is up to the individual operator to decide whether to use a flocculent but once again I quote from the Bard, this time: A midsummer night’s dream ;
‘Lord, what fools these mortals be!’

Allen J Wilson FISPE, Tech IOSH, MInstSRM and William Shakespeare (2341564 to 2341616)