Are we really safe from these chlorinated residues?
We can wonder about the long-term effects of the regular intake of this very reactive molecule.
A 2008 report by the French health watchdog (Institut de veille sanitaire) has been ignored, although its conclusions are worrying to say the least. In fact, it is necessary to know that the free chlorine used to disinfect water reacts with the organic matter present in the raw water and generates derivatives that remain in the water. In the case of trihalomethanes, the average concentration doubles between the plant and the tap. The free chlorine evaporates in the network. Chlorine is also reintroduced at some points in the pipes.
The chlorination of our water is not monitored:
French regulations set a limit for trihalomethanes in drinking water. But most of the controls are done at the outlet of the treatment plant and not in the network. The drinking water regulations do not define a precise level of acceptable chlorine limit. The only recommendations are mentioned in the Vigipirate plan, which requires a minimum free chlorine content of 0.3 mg/L at the outlet of treatment plants. Overall, it seems that the control of the chlorine content in the network is not very reliable. This leads to the risk of under-dosing, causing gastroenteritis epidemics among the population, or over-dosing, the consequences of which are poorly understood at the level of by-products.
Human cancer risks and risks to pregnant women:
Epidemiologic studies have shown an association between chlorination byproducts in drinking water and some human cancers, particularly of the bladder and colon.
Other risks have been raised across the Atlantic, with at least ten similar epidemiological studies, including a Canadian study from Dalhousie University, showing an increased risk of birth defects and miscarriages in women who drink chlorinated tap water.
It is time for consumers to be better informed about the potential risks. Of course, it is understandable that municipalities and water treatment companies do not want to highlight these risks, since they boast the quality of their water in order to regularly raise its price. If consumption were to be reduced, especially by pregnant women, these price increases could be reconsidered.
Do chlorinated pools promote the development of asthma in young swimmers?
Lifeguards have succeeded in having the diseases linked to chlorinated pools (Brooks syndrome, asthma, respiratory insufficiency) recognized as occupational diseases. But what is the effect of chlorine on baby swimmers? The results of a study conducted by Professor Bernard’s team at the University of Louvain are conclusive. He studied a population of 341 children aged 8 to 12, including 41 former baby swimmers: “16.3% of the former baby swimmers had been diagnosed with asthma, compared to 7.7% of the other children. 9.3% had exercise-induced asthma, compared with 3.7% of the other children. Finally, 6.5% of former baby swimmers had recurrent episodes of bronchitis, compared to 3.7% of other children.
Chlorine in tap water
If inhaling chlorinated residues (chloramines, trihalomethanes, bromates) can affect our respiratory tract, what happens when we ingest these products by drinking tap water?
In France, the limits for chlorine are three times higher than in Canada or the United States. To protect the water system from a bioterrorist attack, the maximum chlorination threshold for water was raised from 0.1 mg/L to 0.3 mg/L in 2009.
The WHO standard was even exceeded in Morbihan and Martinique.
Residues with carcinogenic potential
Prolonged exposure to water containing chlorinated residues (especially trihalomethanes) is known to significantly increase the risk of cancer. An American study in California showed a risk of spontaneous abortion in pregnant women who drank tap water with high levels of THMs.