Chlorine in Water, Risk of Bladder and Colon Cancer
Chlorine in Water, Risk of Bladder and Colon Cancer
By Ina Woolcott
Chlorine has been used in the UK to disinfect household water supplies for 100 years. A study has suggested that low levels of chlorine found in tap water, when used to have a bath or shower, can almost double the chance of developing bladder cancer. Scientists have discovered chemical by-products from mains water which contains chlorine - which is used as a disinfectant - is absorbed through the skin and can collect and build up in the bladder. The chemical by-products are known as THMs. These are created once chlorine has been added to the water supply and react with naturally occurring substances such as decomposing plant and animal materials. There are laws stating that THMs mustn’t go above 100 micrograms per litre. The study which was carried out in Spain and documented in The American Journal of Epidemiology suggests that only 50 micrograms per litre - the amount found in some areas of the UK - are necessary to significantly increase the risk of getting bladder cancer. Of course when you go swimming the levels of chlorine in the water are much higher and so pose a greater threat.
The study was conducted in Barcelona at the Municipal Institute of Medical Research comparing 1200 women and men who had bladder cancer to a healthy assemblage of people and inquiring each individual about their exposure to chlorinated water.
* Those living in locations where water contains higher amounts of chlorine than others and bathed in it frequently, were around 83% more likely to develop bladder cancer.
* People drinking high chlorine tap water are about 35% more susceptible to get bladder cancer. Contrasting this a study published in the Journal of the National cancer institute found that long term drinking of chlorinated water appears to increase a person’s risk of developing bladder cancer as much as 80%. The drinking of water was also linked to an increased incidence of colon cancer, and this study was carried out in 1987, so they already new back then.
* Regular swimming pool usage results in a 57% more likely chance to get bladder cancer.
When chlorine is absorbed through the skin it bypasses the liver and thus is not cleansed. When water is drunk a lot of the damaging chemicals are filtered out. The head of research, Dr Christina Villenueva stated the following:
” Inhaling or absorbing of THMs may lead to a higher concentration in target organs such as the kidneys, bladder or colon. Experimental studies have shown a significant uptake of THMs when showering, bathing or swimming in pools. If confirmed, this has significant public health complications.”
In 1999 moves were underway to discontinue the use of chlorine in water supplies as there was already evidence that chlorine can stimulate bladder cancer, but a government committee overthrew this decision. The thing is there ARE already safer methods being employed by some countries such as ozone gas or ultraviolet light, but water companies want to use the cheapest methods of disinfecting available i.e. chlorine. As with a lot of other scenarios, our health is once again second! As long as the costs are low and the prices for us are high - not just monetary wise, also health wise - that is all that seems to matter.
A lot of research has been carried out not just in Spain in relation to the chlorine present when drinking tap water, and we should be wary, although large scale studies are needed to back this up studies need to be carried out on more than 1200 people at one time. Until then it can’t be said for certain that there is a definite higher potential of developing bladder cancer. Any potential cancer risks must be balanced up with the risks of the many infectious diseases that can be caught from dirty water, un-correctly disinfected water. Bladder cancer kills around 5000 people a year in the UK, the biggest cause of which is smoking.
Three years ago there was a link between the chlorine content of water and women having miscarriages or the babies having birth defects.
Filed under: Dare 2B Aware on November 28th, 2007
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