Does it Pose a Potential Health Problem?
What is Nitrate?
Nitrate (NO3) is a colourless, odorless, and tasteless and extremely water soluble molecule made up of nitrogen and oxygen. It is naturally part of the nitrogen cycle where (mainly aerobic) bacteria breakdown animal and vegetable proteins and ammonium compounds – urine, excreta, and foodstuff remains. Ammonium (NH3NH4) – Nitrite (NO2) – Nitrate (NO3). This bacterial mechanism is part of the great circle of life and is how natural and manmade bodies of water, lakes and reservoirs, rivers, wet-lands (where your drinking water comes from), and even the sea is filtered and kept suitable to support the huge variety of life.
Nitrate is also a natural constituent of algae & plants and is found in vegetables at varying levels depending on the amount of fertiliser applied and obviously, on other growing conditions. Most human adults (according to the World Health Organisation) intake between 20-70 milligrams of Nitrate per day with most of this coming from foods like lettuce, celery, beetroot, sugar beet, spinach, and edible seaweeds. When foods containing naturally low levels of Nitrate are consumed as part of a normal balanced diet the Nitrate exposure is not (at this moment in time) thought to be detrimental to most adult humans.
Other common sources of Nitrate contamination in groundwater include animal wastes (wherever animals are reared on farmland, their wastes enter the soil and therefore the groundwater) septic tanks, local sewage treatment systems, decaying plant debris, and industrial pollution from manufacturing processes. Also, as Nitrate is a major constituent of many fertilisers, and as already stated is extremely water soluble; huge quantities of manufactured Nitrate enters the groundwater/water table whenever these fertilisers are added to the soil.
Nitrate Levels in UK Tap Water
The current UK regulatory standard for Nitrate is 50 mg/l – (milligrams per litre). Derived from the water standard advised by the European Union’s Drinking Water Directive. This EU standard is based on the World Health Organisation’s guidelines for drinking water, which is also 50 mg/l – (milligrams per litre). That regulatory standard is intended to ensure that UK drinking water will not cause Methemoglobinemia in human infants.
However, the UK regulatory standards for Nitrate are breached at various times of the year, usually around the summer months, or if a particular area has a prolonged drought. In most years, representative tests for Nitrate on water samples taken from public water supplies in England and Wales just meet the UK regulatory standard for Nitrate. Regular remedial action is usually taken in the few locations where the UK regulatory standard for Nitrate is exceeded; this action involves the installation of special water treatment processes (usually Ion Exchange) to reduce the Nitrate concentrations in the public drinking water. Also, the technique of blending water containing high Nitrates from one supply with water that is low in Nitrates from another; is regularly practised by various water companies across the UK to achieve compliance with the UK regulatory standard for Nitrates.
However, in areas of high population or major urban growth and manufacture – using the greater London, Birmingham, or Manchester areas as examples, water is recycled time and time again; leading to regular localised ‘breaches’ of the UK regulatory standards for Nitrates.
Health Risk of Nitrates?
Methemoglobinemia (blue baby syndrome or cyanosis) – Nitrate/Nitrite poisoning
Young human infants who are fed water or milk formula made with water that is high in Nitrate can develop a condition that medical experts call Methemoglobinemia, and some infants may be more sensitive than others. The condition is also called blue baby syndrome because the most obvious symptom of acute Nitrate/Nitrite poisoning in young infants is the bluish colour of the skin; the skin appears blue-gray or lavender in colour, particularly around the eyes and mouth (this condition is also called cyanosis). An infant with these symptoms (no matter how slight) should be taken to casualty immediately, where an initial blood sample may be taken – the blood sample of an affected infant will be a chocolate brown instead of a healthy red colour. Nitrate poisoning can be treated, and in most cases the infant makes a full recovery. It is has to be strongly stressed, that it is extremely crucial to deal with this problem IMMEDIATELY, because this condition can lead to coma and eventual death if it is not treated promptly.
Young human infants are extremely susceptible to acute Nitrate poisoning because of certain bacteria that may live in their digestive system during the first few months of their life. These bacteria convert Nitrate (NO3) into the more toxic Nitrite (NO2). The Nitrite reacts with hemoglobin (which carries oxygen to all parts of the body) to form methemoglobin, which does not carry oxygen. The level of oxygen in the blood carried throughout the body decreases in proportion to the amount of hemoglobin converted to methemoglobin. As the oxygen level decreases, the infant is slowly suffocated; hence the blue colouration of the skin.
In all cases where the drinking water contains high levels of Nitrate, an alternative source of water low in Nitrates should be found for the human infant. Boiling the water WILL NOT reduce the Nitrate concentration; in fact, it actually INCREASES the concentration by only evaporating the water content. Water that is high in Nitrates should never be used for preparing infant milk formula or in any other way that could result in the infant consuming any liquids with a high Nitrate level.
Around the age of three months, an increase in the amount of the hydrochloric acid in a human infant’s stomach kills most of the natural bacteria that convert Nitrate to Nitrite. By the time an infant is six months old, its digestive system should be fully developed, and none of the Nitrate converting bacteria remain. In older children and adults, Nitrate is absorbed and excreted, and Methemoglobinemia is not usually a concern for most healthy adult humans.
Although no confirmed cases of blue baby syndrome have been associated with Nitrate in breast milk, it may still be advisable for nursing women to avoid drinking water that contains more than 50 mgl – (milligrams per litre) Nitrate. However, infants under one year of age and women who are pregnant are still at risk of certain adverse effects, because when nursing mothers ingest liquids/foods that contain high levels of Nitrate; the amount of Nitrate in breast milk may increase. Some scientific studies have found some evidence suggesting that women who drink water containing high levels of Nitrate during pregnancy are more likely to give birth to babies with certain birth defects. High levels of Nitrate in the drinking water, liquids, and foods given to the pregnant mother may also lower the amount of oxygen available to the foetus. It may be that this potential reduction of oxygen to the unborn foetus, especially the reduction of oxygen supply to a newborn infant’s brain, may result in irreversible brain damage.
Other Health Risks from Nitrates in Your Water Supply Including Cancer
As it is now a medically accepted fact that severe Methemoglobinemia can result in brain damage and death. Pregnant women, adults with reduced stomach acidity, and people deficient in the enzyme that changes methemoglobin back to the normal hemoglobin are all susceptible to Nitrite induced Methemoglobinemia and therefore, should take precautions about the quality of their drinking water and other liquids/foods, especially when it comes to their Nitrate content..
People who have an immune deficiency, heart or lung disease, certain other inherited enzyme defects, or various cancers; may also be more sensitive to the toxic effects of consuming Nitrate than others. In addition, some medical experts also believe that the long-term drinking of water that is high in Nitrate may increase the risk of certain types of cancer.
A number of epidemiological studies have investigated the possible association of Nitrate in public tap water supplies and the incidence of various cancers. As yet, none have provided any firm evidence for determining any direct association. In fact, no adverse effects have even been linked with inhaling Nitrates or Nitrites, so reference concentrations – used to suggest safe levels of a substance and therefore, to assess the potential toxicity when inhaling these compounds – have not been developed. The contribution of Nitrates and by bacterial conversion Nitrites, to the potential to cause various human cancers and the magnitude of the associated risk of actually developing these cancers is unclear. A number of studies have demonstrated that extremely high doses of Nitrite can cause various cancers in research laboratory animals because Nitrites react with secondary amines in food to form nitrosamines, many of which are highly carcinogenic. There is also some medical concern in the US about a possible link between drinking water with high levels of Nitrate and Thyroid cancer.
What can you do if you are concerned about drinking water containing Nitrate?
The technology exists to almost completely remove any level of Nitrate from your incoming public mains or private bore hole – water supply. This can be easily accomplished by the use of a special Ion Exchange Resin, a process that is exactly the same as the one used by water supply companies when they have to reduce the level of Nitrate in their treated water supplied to the public (incidentally, a technology that doesn’t waste water as some other technologies do). This technology can be as simple as a small unit fitted under the kitchen sink, to self regenerating systems in ever-increasing capacities, according to the level of Nitrate free water required by the end-user.
Aquatec – the Pure Water People, a UK-based company, has specialised in the design and construction of these Nitrate Removal Systems for many years. Aquatec has under-the-sink units, self regenerating domestic family units, to units for large retirement homes and hospitals; and even larger units and computerised controlled systems for industrial and agricultural applications, including public aquaria and zoos. If you are at all concerned about the level of Nitrate in your water supply, then don’t hesitate to book your free water test today.by