Should we drink tap water or pure, filtered water? In many countries, tap water contains fluoride, chlorine and other contaminants that are not conducive to good health. In this article, we take a closer look at the research on the health effects of flouride and chlorine as additives in the water supply so that you can make your own informed decision about whether to drink the local tap water.
The debate over the dangers of fluoride has been ongoing for decades. The rationale for the fluoridation of the public water supply is based on the premise that fluoride reduces tooth decay. However, there is very little evidence that adding fluoride to the water supply has any benefit for the teeth. In fact, fluoride has no biological role in the body and is known to be toxic even at low doses. The EPA classifies fluoride as a toxic waste product from aluminium processing, uranium processing and fertilizer manufacture. It is used in pesticides, insecticides, fungicides and even in rat poison in the form of sodium fluoride. This is not pleasant stuff.
Studies have shown time after time that fluoride is a dangerous substance that accumulates in our bodies over time, and that it is ineffective in preventing tooth decay. There have been 37 studies on humans that have linked modest fluoride exposure to reduced intelligence. One study published in the Journal of Environmental Health Perspectives in 2012 found a link between high fluoride levels in drinking water and low IQ levels in children.
This research was based on the analysis of 27 studies and found an average difference of 7 points in IQ between high and low fluoride drinking water. There have been a further 12 studies that linked fluoride to neuro-behavioural deficits. Another effect of excessive fluoride ingestion is dental ‘flourosis’ during the time when teeth are forming. Fluorosis is defined as a change in the mineralisation of the dental hard tissues such as enamel. This results in discolouration of the teeth and ultimately, pitted or broken enamel. According to the Centers for Disease Control and Prevention (CDC), in a study between 1999 and 2004, 41% of the adolescents aged between 12 and 15 in the study had the highest prevalence of flourosis.
The debate continues as to whether fluoridating the public water supply is safe or not. The CDC state that the level at which fluoride is added to water, which is 1 part per million (1ppm), is safe and effective. However, it does make you wonder why fluoride is added to the public water supply in the first place. The original rationale was because it was thought to reduce dental cavities. To my mind, it makes more sense to address tooth decay with good dental hygiene and the reduction of sugary foods in the diet, rather than adding a toxic substance to the public water supply.
Chlorine is a disinfectant that is added to water and to swimming pools to minimise or eliminate micro-organisms such as viruses and bacteria. This process was introduced in the United States in 1904. It has been shown that chlorine is effective at eliminating virtually all micro-organisms. Basically, it is added to the public water supply to reduce the risk of disease and minimise health risks. The rationale makes sense. Ensure that the water remains free of harmful micro-organisms after it has left the treatment plant.
But is chlorinated water safe to drink? There has been much debate on this and one argument is that chlorine is highly toxic to humans and should not be added to the water supply. The other argument is that, at the levels of chlorination used in the water supply, the benefits of having disinfected water free from micro-organisms outweighs any risks of the chlorinated water.
Who is right? What are the health concerns? In the 1970’s scientists discovered that the combination of chlorine with organic compounds in water form Trihalomethanes (THMs) one of which is a form of chloroform as well as other by-products. THM’s increase the production of free radicals and are known to be carcinogenic.
There is an increasing amount of research on the effects of chlorinated water on human health suggesting links to certain types of cancer and various chronic inflammatory conditions. For example, in 1992, a study that made front page news and reported in the American Journal of Public Health, researchers found that people who regularly consumed tap water containing high levels of chlorine by-products have a greater risk of developing bladder cancer and rectal cancers than people who drink unchlorinated water. The research reported that people who drink chlorinated water over long periods have a 21% increase in the risk of contracting bladder cancer and a 38% increase in the risk of rectal cancer. The study estimated that about 9% of all bladder cancer cases per year and 18% of all rectal cancer cases per year are associated with long term consumption of chlorinated water. Are the findings from this study to be trusted? Can it stand up to scrutiny? This particular study was based on what is called a meta-analysis. It seems that this type of analysis has its disadvantages and has aroused concern in some circles. Indeed, it is not considered an exact statistical science by some in the scientific community and if it is used incorrectly, the results may leave room for interpretation. However, other research seems to corroborate the findings to some degree. A population-based, case–control study of adults consuming chlorinated or non-chlorinated water for half of their lifetimes found an increased risk of bladder cancer in those drinking chlorinated tap water. This certainly gives us pause for thought as there is enough evidence available to warrant some concern. Ultimately, it is up to us to make an informed decision about our own health and the measures we take to avoid certain risks.
It is clear that without some kind of water disinfection treatment, millions would suffer or die from deadly infections such as cholera, typhoid, dysentery, salmonella and a myriad of others. But should we continue to drink chlorinated water in the light of evidence that demonstrates health risks? From a probability perspective, the risks of contracting a waterborne diseases such as typhoid or cholera from untreated water are greater than the risks of getting cancer from chlorinated water, particularly given that levels of chlorination are regulated. It is difficult equation to balance and maybe the question should be:- Is there a better way? It would seem so as some cities and states are starting to use alternative means to disinfect their water. In Las Vegas, Nevada and Santa Clara, California, they are moving towards a process called ozonation which is more expensive but with minimal side effects.
Worldwide, over 1000 cities are now treating their drinking water with ozone. If we live in cities or parts of the world where water chlorination is still being used as the primary process to disinfect water, the best method to ensure we have chlorine free water is to install a whole house filter. We’ll take a closer look at water filtering methods in the next article.
Sports & fitness nutritionist, researcher and author on a mission to improve the human condition. Focusing on evidence-based and outcome-based nutrition, training, mindset & environment