PRACA ORYGINALNA

ORIGINAL ARTICLE

ANALYSIS OF THE STATE OF NITRATE POLLUTION OF AQUIFER OF KHARKIV REGION ACCORDING TO LABORATORY TESTS

ANALIZA STANU ZANIECZYSZCZENIA AZOTANAMI WARSTW WODONOŚNYCH W OBWODZIE CHARKOWSKIM NA PODSTAWIE WYNIKÓW BADAŃ LABORATORYJNYCH

Mykola I. Lytvynenko, Olha I. Zalyubovska, Volodymyr O. Korobchanski, Tetiana I. Tiupka, Viktor V. Zlenko, Yuliia N. Avidzba

Kharkiv National Medical University, Kharkiv, Ukraine

ABSRACT

Introbuction: The scientific-methodical substantiation of measures on supplying the population with drinking water of guaranteed quality is one of the main factors of sanitary and epidemiological welfare of the population of the region.

The aim: The aim of this work is the analysis of the state of nitrate pollution of sources of drinking water supply in Kharkiv region

Materials and methods: Studies of drinking water were conducted and evaluated according to the requirements of current standards

Results: In recent years in the area there has been a tendency of deterioration of the quality of drinking water from decentralized water supply facilities (wells and capping sources)

Conclusions: The percentage of drinking water samples with exceeding the established standards on sanitary-chemical indicators of the objects of centralized water supply in recent years is on the average 15%, and it is 30% for the facilities of decentralized water supply.

Key words: drinking water, laboratory tests, water nitrate methemoglobinemia

Wiad Lek 2019, 72, 2, 189-192

Introduction

The scientific-methodical substantiation of measures on supplying the population with drinking water of guaranteed quality is one of the main factors of sanitary and epidemiological welfare of the population of the region. The problem of providing the population with quality drinking water in Kharkiv region is urgent and sharp enough. [4,7,8]

The surface water resources of Kharkiv region are represented by rivers (867), lakes (583), reservoirs (56), rates (2538) and the Dnipro-Donbas channel. One of the peculiarities of water resources is that the rivers, which serve as the main sources of water supply, are also used as sewage receivers. Centralized water supply is provided to only 24% of rural settlements (the rest is 76%, which is 1286 rural settlements which receive drinking water from decentralized sources). [5]

In the vast majority, not the whole territory of the settlement of rural is provided with centralized water supply, but only its central part.

The residents of the area use water for drinking from more than 5,000 wells of public use and from more than 40 thousand individual wells. The water taken from the considerable part of them does not meet the regulatory requirements for sanitary-chemical indicators. [6]

In our scientific work the laboratory tests of water on sanitary-chemical indicators from sources of centralized and decentralized drinking water supply have been conducted and the data of laboratory researches of the experts of the state sanitary and epidemiological service and Kharkiv regional laboratory center of the MOH of Ukraine for the past ten years for the analysis of pollution of aquifer of Kharkiv region with nitrates has been analyzed. The purpose of the article is the analysis of the state of nitrate pollution of the sources of drinking water supply in Kharkiv region for the scientific substantiation of measures to prevent the outbreak of water-nitrate methemoglobinemia.

The first who described the cases of water-nitrate methemoglobinemia in the 50s of the previous century were American scientists, doctors S.Comley and K.Walton. At that time, 278 cases were registered, 39 of which were fatal.

In recent years, according to the literature in various countries around the world, more than 1000 cases have been registered, more than 100 of which have been fatal. For example, in the Czech Republic – 115 cases. According to the Water Framework Directive EU, 2000, the water monitoring for nitrate is required in the community [1].

Nitrates are not methemoglobinemia makers, but by doing the digestive tract with water, under the influence of the intestinal microflora, they are restored into nitrite. The latest enter the bloodstream and block hemoglobin through the formation of methemoglobin (MtHb), which is not capable of entering into the reversible reaction with oxygen and carrying it. If the amount of methemoglobin exceeds 50% of the total amount of hemoglobin, the organism may die from hypoxia of the central nervous system. In all the above cases with the sick infants, the adults remained healthy. It turned out that in their blood methemoglobin does not accumulate due to the destruction of red blood cells methemoglobinemia, so there is a rapid recovery of hemoglobin. The kids, especially of the first year of life, were noticed to have a shortage of methemoglobin reductase, which leads to the accumulation of methemoglobin. That is why, the younger the child, the more severe the disease. [2,3]

The aim

The aim of this work is the analysis of the state of nitrate pollution of sources of drinking water supply in Kharkiv region.

Analysis of the sanitary and epidemic situation that has developed in the region shows that the use of drinking water from centralized and non-centralized sources of water supply can be a risk factor for public health. Microbial, in particular viral, pollution of drinking water can cause an outbreak of viral hepatitis A, for which the water factor of transmission of viral infection is decisive. Non-compliance of drinking water quality with regulatory requirements for sanitary and chemical indicators is one of the reasons for the spread of diseases of non-infectious etiology: water-nitrate methemoglobinemia (excess water nitrates), urolithiasis and cholelithiasis (excess water mineral salts), cardiovascular disease (hard water), diseases of the gastrointestinal tract (excess water sulfates), etc.

The article analyzes the morbidity of the population of Kharkiv region by water-nitrate methemoglobinemia. The discrepancy between the drinking water quality and the regulatory requirements for sanitary-chemical indicators is one of the reasons for the distribution of water and nitrate methemoglobinemia (the excess of nitrates in water).

Materials and methods

Studies of drinking water were conducted and evaluated according to the requirements of DSTU 4808:2007 “Sources of centralized drinking water supply. Hygienic and ecological requirements to water quality and rules of selection”, DSanPin 2.2.4-171-10 “Hygienic requirements to drinking water intended for human consumption”, the sanitary rules and standards of surface water protection from pollution” (SanPiN4630-88), State sanitary rules of planning and development of human settlements, approved by the order of the Ministry of Health of Ukraine dated June 19, 1996 No. 173, GOST 17.1.5.02-80 “Protection of nature. Hydrosphere Hygienic requirements for zones of recreation of water objects “ an information sheet on scientific (scientific and technical) products intended for practical application in the field of healthcare “Method of assessment of the degree of medical and ecological stress in the area of the location of the water recreational zone” No. 76 – 2016

RESULTS AND DISCUSSION

It has been established, that for the last 10 years in drinking water from objects of centralized water supply, the standards for the sanitary-chemical indicators have been exceeded at the level of 15%.

It has been determined that the excess of nitrate content in drinking water from centralized sources of water supply is almost not detected (less than 1%).

In recent years in the area there has been a tendency of deterioration of the quality of drinking water from decentralized water supply facilities (wells and capping sources) as according to sanitary and chemical indicators (exceeding the standards from 38,0% to 45,0%).

High concentrations of nitrates have been detected in 30% of samples taken from drinking water sources of decentralized water supply.

The own research has found that the most polluted nitrates are public wells located on the territory of small settlements (towns and villages of urban type) in the water of which according to the laboratory studies the excess content of nitrates was 3-5 times.

Along with nitrate pollution of water wells established exceeding the established standards of iron up to 10-15 times, suspended solids and chromaticity up to 10 times, sulfates – 2 times.

In addition, it was determined that the levels of bacterial contamination of water of these objects also tend to increase.

These wells are in poor sanitary conditions. The water from these wells is practically not used by the population for drinking purposes. But there is a risk of ingress of contaminated water to groundwater in individual wells of inhabitants of the region.

The main reasons for the poor quality of water are the composition of natural waters, their lack of protection from pollution, stagnation due to insufficient analysis of spring water, the penetration of pollution with surface runoff, a significant anthropogenic load on the territory of settlements, as well as unauthorized and chaotic arrangement of sources of non-centralized water supply.

The general disadvantages in the operation of wells include poor technical condition, lack of annual cleaning and disinfection.

One of the probable causes of pollution of the aquifer is non-compliance and lack of sanitary protection zones of sources of centralized drinking water supply.

Due to the high content of nitrates in well water in the districts of the region, the cases of poisoning by nitrates (water-nitrate methemoglobinemia) among the children under the age of 3 years are constantly recorded. 40 cases of poisoning of children by nitrates were registered in the region from 2006 to 2017. The water for feeding these children was taken from the individual wells and the wells for public use, where the content of nitrates exceeded the statutory rate in 3-8 times (Fig. 1).

As indicated in the graph, the number of cases of poisoning with nitrates in the Kharkiv region tends to decrease. In order to prevent water-nitrate methemoglobinemia in children, the Department of Health of the Kharkiv Regional State Administration issued an appropriate order in which the chief doctors of the central district and city hospitals provide for the systematic carrying out of women’s consultations by medical doctors, general outpatient clinics – family medicine for explanatory work on the inadmissibility of using water from the wells and cupolas for the preparation of baby food; offer pregnant women in the third trimester of pregnancy drinking water from individual and public wells beforehand to study its nitrogen content.

Conclusions

1. The percentage of drinking water samples on sanitary-chemical indicators of the objects of centralized water supply in recent years is on the average 15%, and it is 40% for the facilities of decentralized water supply.

2. It has been found that in drinking water taken from centralized sources of water supply, the excess of nitrate content is almost not detected (less than 1%), and high concentrations of nitrates are detected in 40% of samples taken from the sources of decentralized water supply.

3. 40 cases of poisoning of children by nitrates have been registered in the region for the last 12 years.

4. The unsatisfactory technical conditions, the lack of annual cleaning and disinfection should be classified as some of general disadvantages in the operation of wells.

5. To prevent the occurrence of diseases of children under the age of 3 years on the water-nitrate methemoglobinemia, the scientists of Kharkiv national medical university constantly provide recommendations concerning the non-use of water from wells and natural sources for infant feeding, as well as the need to implement continuous monitoring of the water sources of decentralized drinking water supply.

6. In order to improve the sanitary and ecological state of surface reservoirs, the scientists of Kharkiv national medical university have developed and implemented a set of preventive measures, the main of which are:

– conducting a thorough analysis of the causes of deterioration or improvement of the quality of water of open water bodies by the scientists;

– scientific substantiation of proposals for the implementation of measures to stop discharges of insufficiently cleaned and untreated sewage into the reservoir, disinfection of waste water (special attention is paid to the treatment facilities located in rural settlements);

– continuous monitoring of pollution levels of surface water bodies by organoleptic, physic-chemical, microbiological indicators, as well as on salts of heavy metals, pesticides, strontium and cesium;

– to ensure work with the media on informing the state of surface water and drinking water.

7. The implementation of the above recommendations in Kharkiv region will help to reduce the incidence of water-nitrate methemoglobinemia and improve the quality of drinking water in the region.

References

1. http://zakon.rada.gov.ua/laws/show/994_962

2. Goncharuk E. Communal hygiene. Health, 2006;792.

3. Datsenko І. Preventive medicine. Health, 2004;792.

4. Rybalova O., H. Korobkova, A. Kozlovska Analysis of the ecological state of the river Siversky Donets in the boundaries of Kharkiv region. Сollection of scientific articles of the IX International Scientific and Practical Conference Ecological safety: Problems and Solutions. Kharkiv, 2013;1:25-27.

5. Report on the state of the environment in Kharkiv region for 2016. State Department of Environmental Protection in Kharkiv region, 2017;354.

6. Ecological atlas of the Kharkiv region State administration. State administration of environmental protection in the Kharkiv region, 2005;80.

7. Lytvynenko M. Ecological and hygienic substantiation of optimization of the regional system of recreational use of reservoirs: author’s abstract. dis for obtaining sciences. Degree Candidate medical Sciences: special 14.02.01 «Hygiene and professional pathology», Kharkiv, 2016;25.

8. Scherban М, Lytvynenko M., Harnik V. Comparative analysis of the status of recreational reservoirs of Kharkiv region by the results of sanitary and environmental studies. Odesa Medical Journal, 2015;6:62-66

Authors’ contributions:

According to the order of the Authorship

Conflict of interest:

The Authors declare no conflict of interest.

СORRESPONDING AUTHOR

Mykola I. lytvynenko

Kharkiv national medical university

4 Nauky Avenue, Kharkiv, Ukrain

Tel.: +38096-215-11-48.

E-mail: kkld1@ukr.net

Received: 10.11.2018

Accepted: 31.01.2019

Fig. 1. Cases of nitrate poisoning (water-nitrate methempglobinemia) among the children under the age of 3 years in Kharkiv region for the period 2006-2017.