Swimming Pool UV treatment

At last - a way to disinfect domestic pools and spas with minimal chemical usage!

	Until now, the only way to ensure a safe and pleasant pool environment was by careful use of strong pool disinfection chemicals. Now, an ultraviolet disinfection system has been produced for domestic swimming pools, capable of providing full primary disinfection of pool water and reducing the chemical dosing requirements by 50 % or more.

The advantages of this system include:

• More pleasant bathing in a very low chemical environment
• Dramatically reduced chemical costs
• Possibility of zero-chlorine bathing, using peroxide disinfectants
• Unrivalled protection against contamination in filter media
• Safety-net protection against loss of chemical dosing - real life tests with no dosing for a month proved the pool still stayed fresh
• Instantaneous disinfection of the pool water, at every pass
  Very low power consumption
• All stainless steel construction

All of these advantages with low purchase cost and extremely low running costs.

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Shortwave Ultraviolet light has two important properties that are major benefits in swimming pools:

1. It is a totally chemical-free disinfection method, and
2. It can photo-oxidise and destroy combined chlorine molecules (chloramines and other organic pollutants).

It is important to distinguish between 'public' and 'private' pools when considering how to use ultraviolet treatment.

Public Pools

The main benefit in public swimming pools (where high bather loads create inherent water pollution problems) is photo-oxidation, to split and destroy chloramines and other organic molecules, and in particular to reduce combined chlorine levels.

Ultraviolet (UV) disinfection is an electrical and totally chemical free means of full primary disinfection, which it is impossible to overdose, and would appear to be the ultimate solution. In reality, UV disinfection cannot totally replace chlorine, as it does not provide the necessary residual germicidal effect in the body of the pool. What is a
unique advantage of UV, is that it reduces the required levels of combined and free chlorine to an absolute minimum by photo-oxidation, without the introduction of any additional chemical to the water.

Private Pools

Private pools have low bather levels, and should generally suffer few problems with combined chlorine. Here, the use of UV treatment is mainly to provide water disinfection, with little or no chemical residual added to the water. The 'Poolmaster'; units can be used in two different modes:

• With a trace of disinfectant chemical added to the pool to act as a low-level residual disinfectant. This can be either Chlorine or Peroxide based, as the customer prefers. It should be used at the minimum possible levels, eg. 0.5 mg/l for free chlorine and say 3 mg/l for peroxide, and adjusted according to local conditions so that no algal growth occurs no the pool surfaces. (It should be added after the UV treatment chamber, to minimise the effect of UV light on the chemical).
  
• In private pools where there is no public health risk implication, the 'Poolmaster' units can be used as primary disinfection without any residual chemical dosing system. The UV equipment will also help control waterborne algae, but can have no effect on algae which are growing on pool surfaces. Pools can stay fresh and clear for weeks, but from time to time there will be a need to 'shock dose' the pool with chlorine or peroxide, to kill off algal growth. This method is often preferred by customers who chose UV disinfection to avoid bathing in chemically dosed water.
  

Full range of sizes to suit all pools

Swimming Pool vapours linked to child asthma

About one child in eight in Britain has asthma, six times as many as in the 1970's. Up to half of these cases may be hereditary, but researchers have suggested many reasons for the increase.

Evidence that chlorine may be a culprit has been slight, but a study last year from Birmingham suggested that people working at indoor swimming pools and frequent swimmers were more at risk from asthma.

Dr Alfred Bernard, a toxicologist at the Catholic University of Louvain Brussels, has found a complex chain of reactions in children's lungs in response to a by-product of chlorine. He says that damage to cells deep in the lung is similar to damage seen in the lungs of regular smokers. Dr Buernard says in <i>Occupational and Environmental Medicine</i> that nitrogen trichloride is a volatile by-product of chlorination that is readily inhaled.

It is generated when Chlorine comes into contact with organic substances such as sweat or urine.

The researchers measured levels of proteins in the lungs of a small group of children and adults before and after they had been swimming in an indoor pool.

The second part of the study looked at asthma incidence in 2000 children and their attendance at indoor pools.

The found that regular attendance at a swimming pool was "consistently and significantly" associated with destruction of the cell linings deep in the lungs, which made them more susceptible to the agents that cause asthma.

Chest tightness after exercise and overall prevalence of asthma were also linked to the total amount of time spent at indoor pools.

Dr Bernard says that the time may have come to use alternatives to chlorine for disinfecting swimming pools.

"The question needs to be raised as to whether it would not be prudent in the future to move towards non-chlorine based disinfectants or at least to reinforce water and air quality control in indoor pools in order to minimise exposure to these reactive chemicals" he says.

Prof Martyn Partridge, chief medical adviser to the National Asthma Campaign, said, "This is an interesting study and exposure of any child to a chemical which may damage the airways is clearly a matter of concern and requires further investigation".

He gave warning, however, that care should be taken in interpreting the link between swimming and the rise in asthma.

"It is unlikely that swimming, at least by itself, could really be the cause for the increase of asthma", he said.

Taking part in swimming could simply indicate a type of lifestyle linked with an increase in risk of asthma he said.

It was also possible that the results might be distorted by families with a history of asthma being more likely to go swimming because of the widespread knowledge that exercising in this way was less likely to provoke attacks of asthma compared with other types of physical activity.

"Whilst we welcome research such as this much more work needs to be done in this field before we can draw any conclusions", he said.

Full Range of Filtration Equipment and Accessories Available

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For further information:

Tel. 01237 441524

Email: andrew@andrewmacwilliam.co.uk