Clean Drinking Water

Clean drinking water: is our precious resource contaminated?

by The Alliance for Natural Health

About water

Water is a truly remarkable chemical substance that is arguably our single most important natural resource. If we do not consume water for a few days, we die, whilst we can survive for weeks without food.

Water appears to be unique when compared with the 15 million or so chemicals we know something about. It is its unique and anomalous properties that are, probably more than anything else, responsible for life on our planet. One aspect of its uniqueness that we so often take for granted without giving it thought is that the solid form (ice) is less dense than the liquid form (water). Another unique feature is that, given its very low molecular weight, water would be expected to boil at around –90oC, but it doesn’t! We all know that water is comprised, as its formula H2O suggests, of two atoms of hydrogen and one of oxygen, but there is so much more to it than that…

In the water molecule, the single electron of each hydrogen atom is shared with one of the six outer-shell electrons of the oxygen atom (creating two covalent bonds), leaving four electrons that form two non-bonding pairs. So many of the unique properties of water originate from the way in which the size and nuclear charge of the water molecule’s single oxygen atom distorts the electronic charge clouds of the atoms of other elements when these are chemically bonded to it.

Importance of water molecule clusters

Liquid water is much more than millions of discrete H2O molecules. It is actually a highly mobile, vibrating and forever changing cluster of water molecules in which the hydrogen bonds between individual water molecules are continuously breaking and reforming.

We know that water structure, or the arrangement of the molecules in a given volume of water, varies according to many factors including temperature and pressure. We also know that the structure and properties of water within cells, particularly adjacent to membranes in cells or organelles (sometimes referred to as vicinal water), is very different to the structure of bulk water. The key point here is that the unique structure of water within cells is purely a result of the geometry of the surrounding hydrogen bonding sites.

We also know that to get water into cells (cellular hydration), the main purpose of water consumption, there can be advantages in having smaller rather than larger clusters of water. Some scientists argue that a hydrogen-bonded cluster in which four H2Os are located at the corners of an imaginary tetrahedron is an especially favourable (low-potential energy) configuration, but the lifetime of such clusters will be incredibly brief (theoretically measurable in a picosecond [10-12 second] time scale).

The bottom line is that, although there are hundreds of products available that purport to provide us,,often without supporting scientific evidence,,with the correct form of structured water, we should not deviate from the primary object of water in health: water should be delivered to the body to optimize its flow into the body’s cells.

In addition, the body is almost certainly more capable of dealing with water in its pure state, rather than water that is loaded with contaminants, some of which have only become commonplace in our diets or water sources within the last 20 to 50 years.

Is our drinking water contaminated?

On a global scale there is no doubt that pathogenic microbes in water present easily the greatest proven risk to human health.

The World Health Organization and many national or regional authorities have stipulated safe levels for a diverse range of toxins, these levels being based largely on limited data on individual contaminants and on the degree of water purity that is technically and economically feasible from a water treatment viewpoint. These levels have never been developed according to risk assessments on the combined impact of numerous contaminants because the scientific data required to evaluate toxic mixtures in drinking water, as well as in other aspects of our environment, is more or less impossible to obtain.

It is not hard to argue that the existing systems of risk analysis based on detection of individual elements and compounds by mass spectrometry (MS) and high pressure gas liquid chromatography (HPLC) and comparison with ‘accepted standards’ is technically flawed as it ignores the effects of mixtures. Grabbing this problem by the horns is a US company (Environmental Toxicology Laboratory Inc.) that is developing a means of assessing the toxicity of mixtures in drinking water by evaluating the swimming pattern of a chemically ultra-sensitive, flagellate micro-organism when subjected to different quality waters.

The key categories of contaminant in drinking water are summarised in the below:

• Pathogenic organisms
  Chlorination of water exists to control or eliminate pathogens from our water supply, but periodic outbreaks of Escherichia coli, Cryptosporidium, coliforms and gastro-intestinal viruses are testament to the fact that treatment does not always exclude these disease organisms. The double-edged sword is that if we wish to increase the concentration of chemicals in our water to guard against infectious agents, we must also accept the increased risk posed by the chemicals used to treat the water.
  
• Disinfection products
  Sodium hypochlorite, chlorine gas and chlorine dioxide are extremely widely used for water disinfection purposes and there is increasing evidence that these chlorinated compounds can contribute to some very serious health problems. Known harmful effects include eye/skin irritations, stomach discomfort and anaemia. Absorption of chlorine can be greater through the skin from the taking of showers and baths than via drinking water. Most of the long-term health problems associated with chlorine are caused by chlorine by-products. Ozone is also sometimes used for drinking water disinfection, but its use is also not without risk from by-products.
  
• Disinfection by-products
  Hundreds of different compounds can be formed from the reaction of sodium hypochlorite (chlorine) with other compounds present in drinking water and many of these are known to be more hazardous than chlorine itself. They include 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone, or ‘mutagen-X’, also commonly referred to as MX and the trihalomethane (THM) group (e.g. bromodichloromethane, chloroform, bromoform). Additionally, where chlorine dioxide or ozone are used in disinfection to reduce formation of hazardous trihalomethanes, toxic by-products may be formed, such as chlorite (from chlorine dioxide) and bromate (from a reaction between ozone and bromide which may be naturally occurring in source waters). Many members of this group are carcinogenic and they may contribute to liver, kidney and central nervous system disorders. Children and babies (especially the unborn) are particularly vulnerable to such compounds.
  
• Inorganic chemicals
  These comprise a very long list, including various metals such as aluminium (used to clarify water in treatment plants), lead (in old water pipes and solder), cadmium (naturally occurring or from water pipe solder and electroplating); arsenic (naturally occurring in some waters); and also fluoride (naturally occurring and/or added to some water supplies in a misguided attempt to reduce dental caries). While there are many potential adverse effects caused by excessive intakes of any of these inorganic chemicals individually, no one is in a position to elucidate what the combined effects of the multitude of chemicals in a given water supply might be.
  
• Organic chemicals
  These include a large range of industrial chemicals like dichlorobenzene and dichloroethane, pesticides (herbicides, insecticides and fungicides and their breakdown products), dioxins (probably the most inherently toxic group of compounds known), endocrine-disrupting xeno-oestrogens (from contraceptive pills and plasticizers in food and drinking containers and plastic tableware) and a wide range of other persistent compounds discharged by industrial chemical plants, dry cleaners, timber preservation plants, run-off from landfill sites, agriculture, etc. Some of the most persistent compounds still causing problems in the environment are those which are no longer used industrially, such as polychlorinated biphenyls (PCBs). Persistent organochlorine compounds are fat soluble and accumulate over time in the body. Endocrine-disrupting chemicals are now known to cause biological effects at any detectable level, with limits of detection being down to around 0.1 nanograms per litre for bisphenol A (a plasticizer) and estradiol (from contraceptive pills). In addition, we don’t know categorically the significance of long-term or lifetime exposures to low levels of mixtures of these compounds but much of the existing scientific evidence suggests that persistent organic pollutants (POPs) and endocrine disrupters may present very substantial, long-term health risks.
  
• Radionuclides
  Alpha and beta particles, as well as radium and uranium are among several radioactive contaminants that have been found in water sources as a result of decay or erosion of both naturally occurring minerals or rocks in the Earth’s surface and of man-made materials or wastes.

Risk assessment of water contaminants

With the rapid development of highly sensitive analytical equipment such as combined High Pressure Liquid Chromatography/Mass Spectrometry and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), detection of extremely small quantities of contaminants in drinking water is now feasible. However, it is not just the presence of these contaminants that is an issue, it is how biologically significant their presence is.

Risk assessment approaches are increasingly being used to evaluate the relative importance of contaminants in drinking water, as in other areas of human health. By and large, these assessments are based on dose-response data derived from laboratory tests on surrogate species such as rats and mice for assessing risks in humans and on fish and other wildlife for assessing risks in the environment. More comprehensive risk assessments employ a tiered approach, so that substances that represent zero or minimal risk are eliminated from detailed, time-consuming and expensive risk assessment early in the process. Uncertainty and probability are also incorporated into the more complete risk assessments for contaminants that are thought to present a more serious risk to health.

One of the greatest problems with these classical, risk assessment paradigms used to assess contaminant risks to date is that they have not taken adequately into account the cumulative risks associated with long-term (lifetime) exposures, nor have they taken into account the effects of mixtures of contaminants. The reason for this is almost certainly that governments appreciate the consequences of such comprehensive risk assessment: most drinking water would likely be assessed as unsafe for human consumption.

Taking control of the situation – in your home

So we are left with justifications from myopic, pseudo-science-justified risk assessment regimes, almost as defective as the ones that have been recently used to assess the safety of nutrients, which have been carefully adjusted to inform us that our tap water is safe most of the time. On weighing up a large part of the available evidence, I simply do not believe it.

Using some sort of point-of-use filtration system to reduce the diverse range of contaminants in tap water has to be one of the best investments for any household. If these systems rely on replaceable filters, it is essential that the filter is replaced according to the manufacturer’s specification, otherwise they can themselves release contaminants into the drinking water or become hotbeds of microbial contamination.

References

Anonymous, Current Drinking Water Standards, US Environmental Protection Agency, 2002 (http://www.epa.gov/safewater/mcl.html).

Falconer IR. Are endocrine disrupting compounds a health risk in drinking water? Int J Environ Res Public Health, 2006;3(2):180-4.

Fujimoto T, Kubo K, Aou S. Prenatal exposure to bisphenol A impairs sexual differentiation of exploratory behaviour and increases depression-like behaviour in rats. Brain Res, 2006; 1068(1): 49-55. Epub Dec 27, 2005. Hirose A, Nishikawa A, Kinae N, Hasegawa R. 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX): toxicological properties and risk assessment in drinking water. Rev Environ Health, 1999;14(3):103-20.

Liu K, Cruzan JD, Saykally RJ. Water clusters. Science, 1996; 27: 929-93.

Lower, S. A gentle introduction to the structure of water (website) http://www.chem1.com/acad/sci/aboutwater.html and associated links

Ritter L at al. Sources, pathways, and relative risks of contaminants in surface water and groundwater: a perspective prepared for the Walkerton inquiry. J Toxicol Environ Health A, 2002; 65(1): 1-142. Review.

Rodriguez-Mozaz S, de Alda MJ, Barcelo D. Monitoring of estrogens, pesticides and bisphenol A in natural waters and drinking water treatment plants by solid-phase extraction-liquid chromatography-mass spectrometry. J Chromatogr A, 2004; 1045(1-2): 85-92.