UV vs. Chlorine

UV offers the best solution to the dangers of combined chlorine.

The dangers associated with using chlorine for swimming pool disinfection are once again causing wide spread debate throughout the leisure industry. Recent research links chlorine by-products in indoor swimming pools with asthma in children and other health risks, such as increased risk of lung infections, lifelong asthma, respiratory problems and skin and eye allergies. This has understandably raised serious concerns regarding allowing young children to swim in chlorinated pools. 

Ultraviolet treatment systems have therefore become increasingly favoured by this industry as their ability to break down and remove problem chloramines offers a real, practical and cost efficient solution to what is seen as a major hurdle that the leisure industry must overcome.

Researchers from Catholic University of Louvain, who published their findings in the ‘European Respiratory Journal', suggested that "chlorinated pool attendance can increase the risk of asthma and respiratory allergies by making the airways more sensitive not only to allergens but also to infectious agents".

The researchers further concluded that when chlorine in swimming pools combines with sweat, saliva and urine from swimmers produced trichloramines, chemicals that irritate and weaken the lungs, causes itchy skin and burning red eyes. When analysing the rates of wheezing, asthma and other ailments in almost 190,000 13 and 14 year olds in 21 European countries, the results showed rates of asthma rose by 2.7% and 3.39% respectively among regular pool users. In a number of cases the damage was equivalent to that found in heavy smokers.

A further separate study carried out by the Occupational Lung Disease Unit at the Birmingham Heartlands Hospital in the UK found that nitrogen trichloride (produced by Chlorine) was a cause of occupational asthma in poolside workers, such as lifeguards and swimming instructors. The study further noted that during the Olympic Games held in Australia, more than one quarter of the American swim team suffered from some degree of asthma.

So how can UV offer a solution?

A correctly sized, medium pressure UV system breaks down and removes problem chloramines, which are formed when free chlorine reacts with organics, such as sweat, body fats and urine, brought into the pool environment by bathers. Unlike low pressure lamps, which have a peak output of 254nm, medium pressure lamps are polychromatic and have a broader UVC output between 185nm and 400nm. This broader range of UVC light output is what removes nuisance mono-, di- and tri-chloramines.

The result is water quality that is not only much safer for patrons of all ages, but offers a much more inviting and healthy bathing environment. After just a few days of UV operation, combined chlorine levels typically fall to low 0.1 ppm or lower. Problems with itchy skin, burning red eyes, chlorine smell and corrosive condensation are eliminated and the pool water is transformed into sparkling and glacier clear water.

Additionally, medium pressure UV systems provide an increased level of disinfection, protecting against the 17 known chlorine resistant micro-organisms, such as Cryptosporidium and Giardia, which have a thick outer membrane making them highly resistant to traditional chemical disinfection, increasing safety and limiting the risk of costly outbreaks.