Everyone has probably heard that early vegetables and fruits are very often the cause of poisoning. But drinking water, which contains an increased level of nitrates, is no less dangerous, because water is consumed every day by everyone, without exception. A significant part of the population uses water from public mine wells, individual tubular wells, and springs for drinking purposes.
Of particular concern is the presence of elevated nitrate levels in drinking water. Nitrates – are salts of nitric acid. They enter the water with household and agricultural wastewater (from fields treated with fertilizers, livestock and poultry farms, cesspools and yard latrines, etc.). The highest concentration of nitrates is observed in surface springs, groundwater and yard wells.
Water contaminated with nitrates is extremely dangerous for the child's body, especially for children in the first months of life. The risk of developing water-nitrate methemoglobinemia in children, especially in the first year of life, is primarily associated with the imperfection of the body's enzyme systems and biochemical processes occurring in it. Chronic nitrate intoxication develops with prolonged consumption of nitrate-contaminated water and vegetables.
Elderly people, people with anemia, respiratory and cardiovascular diseases are also sensitive to nitrates. Methemoglobin levels above 50 % can be fatal. In lower concentrations, this will manifest itself in lethargy, fatigue, the development of vegetative-vascular dystonia, cardiovascular disorders, decreased performance, cyanosis, and in children, in addition, impaired physical development, decreased attention and concentration during study.
It is forbidden to use water from wells with nitrate content exceeding regulatory values. The permissible concentration of nitrates in drinking water is 50 mg/l.
According to Ukrainian researchers, in case of drinking water with a nitrate content of more than 50 mg/l, water-nitrate methemoglobinemia may occur. In the body, under the influence of intestinal microflora, nitrates are reduced to nitrites, which penetrate the blood and block hemoglobin with the formation of methemoglobin. A severe form of this disease (toxic cyanosis) occurs exclusively in infants who are artificially fed with dry nutritional mixtures. Characteristic manifestations of this disease: cyanosis (blueness) of the nasolabial triangle, earlobes, fingertips - acrocyanosis, cyanosis of the mucous membranes, tachycardia (increased pulse rate), shortness of breath, then convulsions. Cases of fatal outcome are known.
Mild forms of methemoglobinemia associated with the use of drinking water with a high nitrate content are found in children of all age groups and adults. These forms are characterized by weakness, pallor, increased fatigue, which, due to insufficient awareness, can be explained by other reasons. The development of this pathology is facilitated by dyspepsia and intestinal dysbacteriosis, the manifestation of a systematically increased content of methemoglobin in the body is depression of the central nervous system (headache, dizziness, fatigue, drowsiness), heart rhythm disturbances, circulatory disorders and hemolytic anemia. In children, the risk of goiter and infectious diseases of the upper respiratory tract increases when drinking water with a high nitrate content. Severe methemoglobinemia can be fatal if it is not recognized in time and emergency treatment is not started.
Methemoglobinemia is rare in adults, but there is a possible link between long-term consumption of water with high nitrate levels and an increased risk of bladder and ovarian cancer. Pregnant women are particularly at risk from drinking water contaminated with nitrates.
According to information published in Ukraine, nitrates and nitrites contained in drinking water can lead to an increase in the prevalence of circulatory system diseases, blood diseases, and blood-forming organs among the population.
Follow these rules to reduce the risk of nitrate exposure to your body:
- Do not drink water from wells and wells where the nitrate content exceeds the regulatory limit (50 mg/l). This is especially true for children and pregnant women;
- to prepare food or give it to a child under 3 years old to drink, use drinking water that is free of nitrates;
- The location of pump rooms, wells or springs should be located in an uncontaminated and protected area. This location should be located upstream of the groundwater at a distance of at least 30 m from highways with intensive traffic and at least 50 m (for individual wells - at least 20 m) from toilets, cesspools, sewage structures and networks, fertilizer and pesticide warehouses, livestock holding areas and other places of soil and groundwater contamination;
- Wells must be cleaned at least once a year: pump out the water, clean the walls with metal brushes from plaque and the bottom from sediment, unnecessary things that could accidentally get into the well, with subsequent disinfection. After that, the water must be pumped out again and the well must be used only after the next filling and laboratory testing of drinking water;
- The area near the well, spring catchment or pump room must be kept clean and surface runoff must be drained; within a radius of 50 m from pump rooms, wells and spring catchments, it is not allowed to wash cars, arrange animal watering places, water bodies for waterfowl, place devices for preparing pesticides and carry out other activities that may lead to soil and water pollution.
- It is also prohibited to arrange pump rooms, wells and spring catchments in places that are flooded, subject to erosion, landslides and other deformations, in low-lying and swampy areas.
- To insulate and protect wells and spring catchments from freezing, foam concrete, mats made of clean straw, hay, shavings, etc. can be used, but the specified material must not enter the water intake. It is forbidden to use manure, humus, etc. for this purpose.