Abstract
The main positions of the new standard on drinking water are provided. The inconsistency of existing approaches to the assessment including methodology of drinking water quality was substantiated. The main advantage of the new standard is the inclusion of integral methods of water quality, universal for all kinds and types of toxic compounds, irrespective of their origin and nature of the action.
1. Introduction
Drinking water, that is, the water whose organoleptic, physicochemical, and biological properties meet human biological needs and has neither color nor smell, should have a taste determined by the presence of physiologically necessary salts of calcium, magnesium, sodium, and potassium in corresponding concentrations without which metabolism in the human organism is impossible.
What optimal parameters should the water possess to be completely safe from the biological and physiological points of view?
For the first time in the world in 1853, in Brussels, at the International Congress of Hygienists, an attempt was made to set a standard for drinking water, which would include only nine controllable components. Among them there were vitally important substances such as magnesium, calcium, total mineralization (determined mainly by the presence of salts of sodium and potassium), and the content of oxygen in the water, sulfates, chlorides, nitrates, and ammonium. However, the age of industrialization, a fast development of the agroindustrial complex and the emergence of megapolises with compact settlement of people, whose number dramatically increased, started on the planet. A further development of civilization became impossible without the creation of civilized systems of water supply and a complex of water disposal facilities. In connection with the worsening of the ecological state of surface and underground sources the issue of water quality control, used by people for drinking purposes, became more acute. As a result of a low quality of drinking water real threats to the sanitary-epidemiological situation in various regions of the planet cropped out. And only early in the 20th century the first standard for drinking water appear in the USA. After almost a century after adoption in Brussels of the first recommendation for drinking water quality a document of the World Health Organization (WHO) was published, which today, at the beginning of the 21st century, proposes to bring under regulation 95 indices of which 26 are toxic substances, whose presence in drinking water is undesirable. The US standard regulates 102 indexes in drinking water, where complete absence is required for as many as 35 toxic indexes.
A high level of technogenic load on water bodies, the use of imperfect technologies of water conditioning, and secondary contamination of the water in distribution networks result in the ingress to the drinking water of a substantial amount of inorganic and organic pollutants whose joint effect on the human organism causes the effect of synergism known in chemistry and biology, posing real threat to human health. In the situation that has taken shape there is in principle no possibility to provide the population of any country or continent with quality and safe for human health drinking water [1–4].
An increase of the quality of the water being controlled by a national standard in various countries of the world does not solve the issue of obtaining safe drinking water at the centralized water conditioning stations either. All this calls for the ever more expensive equipment and complication of technological processes.
Against the background of such catastrophic changes in the quality of the environment the monitoring of several tens of substances in drinking water causes, to say the least, a surprise. A surprise is also caused by a lack of understanding of the fact that in pursuit of “technical progress,” even increasing the amount of controllable components in drinking water several times as much, one cannot give any guarantees that it is in fact drinking water and safe for human health. Even the use of underground water at present does not always guarantee the quality of the drinking water obtained, especially if one takes into account the fact that an absolute majority of organic matter in the environment under the effect of various physicochemical and ecological factors undergoes biotransformation into unknown and, most often, into unpredictable compounds. According to the aforementioned synergism the effects of two or more compounds of toxic nature of each individually taken substance increase in that case if this substance initially is not toxic. Hence the senselessness of using classic approaches to the assessment of drinking waters follows. The notion itself of “normalizing maximum allowable concentrations in drinking water of different toxicants” purportedly safe for human health is, as a matter of fact, immoral.
The proposed new standard include fundamentally new, very effective integrated methods of monitoring water quality, which are designed for revealing acute toxicity at the level of organism and finding chronic toxicity at the cellular level using cytogenetic methods on biological objects for this purpose. These methods are universal for all types and kinds of toxic compounds irrespective of their origin and the nature of their effect.
The new Standard for Drinking Water includes three different regulatory documents [5]:(i) GOST (state all-union standard) for tap water (conditionally drinking); (ii) GOST for drinking water of increased quality (the water absolutely safe for human health);(iii) GOST for bottled water.
A new concept of providing the population with quality drinking water along with the general provisions and regulation requirements of the quality of drinking water accepted in the European Union, the WHO, and the Codex Alimentarius [6–10] has been taken into account in the development of the standard [11–15].
Such a concept provides for the following. Water safety in terms of toxicological and microbiological indices is prepared at waterworks. This water is suitable for household or domestic use and is fed to the distribution networks. In this case it is obtained mainly from the water of surface sources.
High-quality drinking water in the amount sufficient for satisfying human physiological needs is prepared at the consumption site in the plant of water pump rooms. It is then not fed to the distribution network but is supplied to the consumer by other methods (by gravitation flow or bottling). Such drinking water is obtained mainly from underground water protected against anthropogenic influence or from tap water.
The fundamental feature of the new standard is the regulatory justification of a new conceptual approach to water supply of population with quality drinking water. It provides economic water supply by utilizing the differentiating consumption of drinking water depending on physiological, sanitary-hygienic, and economic needs of human over one 24-hour period in a specific populated area. The necessity of such an approach is determined by the following objective reasons: unjustified use of quality drinking water for sanitary-hygienic needs; unsatisfactory state of transportation and distribution networks of the system of centralized drinking water supply; discrepancy of the technology of drinking water treatment in centralized systems of drinking water supply to the water quality in a water source; unjustified high economic costs for reconstruction and modernization of the systems of centralized drinking water supply for the preparation of high-quality drinking water in a volume substantially exceeding physiological and sanitary-hygienic human needs.
The second fundamental distinction of the new standard is the fact that the main accent was made on new approaches to the assessment of the quality of drinking water in terms of integral indexes of water toxicity, which is set by the methods of biotesting according to standardized techniques. This makes it possible to obtain objective information on the quality of drinking water before the conduction of a detailed analysis by all indices. Such an analysis is expedient in the case of finding toxicity and the necessity of establishing cause of its emergence.
The third fundamental distinction of the new standard is the requirement of complete absence of all toxic chemical and biological pollutants in drinking water designed for human consumption.
The employment of the methods of assessment of the drinking water quality by the integral indexes makes it possible within short terms and at the lowest economic costs to assess the suitability of drinking water for human consumption.
Unlike the methods of chemical analysis adopted today in the world (more than 100 indexes of water quality), the employment of the integrated methods of biotesting makes it possible to substantially (~ by 3-4 times) reduce the amount of controlled indexes.
It is a well-known fact that in the modern period in all countries of the world units, devices of various powers, and miniplants for add-on treatment of drinking water from various sources of water supply were used on a wide scale including from drinking water of centralized water supply and the center of realization or the pouring of tertiary treated drinking water to the containers of the consumers. An indispensable condition of achieving all regulatory indexes of drinking water safety is the setting of certain requirements of drinking water of both centralized and uncentralized systems of water supply.
By microbiological indexes drinking water should conform to the requirements given in Table 1.
By mycological indexes (micromycetes) drinking water should be in line with the norm given in Table 2.
Toxicity of drinking water of uncentralized water supply is an integral (express) quality index of drinking water in the case of suspicion of contamination of a water source or a distribution network with toxic compounds. The list of indices, test objects, and norms for determination of toxicity obtained from the results of biotesting are given in Table 3.
Radiation safety of drinking water shall be determined by the next acceptable levels: total volumetric activity of α-radiators (Σα-activity) not exceeding 0.1 Bq/dm3 and total volumetric activity of β-radiators (Σβ-activity)—1.0 Bq/dm3.
By organoleptic and chemical quality indexes, which affect organoleptic properties, drinking water should correspond to norms given in Tables 4 and 5.
According to toxicological indices of harmlessness of the chemical composition drinking water should be in line with norms given in Table 6 and the EC directives [6].
For the water supply system, which uses reagent water treatment methods prior to its delivery to the distribution network, during pouring out, transportation, and storage for a set time of suitability and in conducting research the indexes given in Table 7 are additionally taken into account. The content of substances that are formed and enter the drinking water during its treatment should not exceed the norms given in Table 7.
Reagents, introduced as preservatives for drinking water, shall be in accordance with Table 8. Other substances and methods for preservation of add-on purified bottled water from a noncentralized drinking water supply avoid the introduction of carbon dioxide and silver ions.
Thus, the approval and introduction of the new standard will allow us:(i) to substantially reduce capital and operational costs for obtaining high-quality drinking water in amounts sufficient for meeting physiological needs of the population;(ii) to reduce costs for exercising control over the quality of drinking water intended for human consumption as a result of using integral methods of assessing water quality without reequipment of chemical-analytical laboratories with expensive equipment;(iii) to improve the state legislative database for providing the population with good-quality drinking water, safe for human health.
Designations and Abbreviations
| BCG: | Groupofcolibacillusbacteria |
| Bq: | Becquerel |
| PFU: | Plaque-formingunits |
| GMN: | Generalmicrobialnumber—numberofsaprophytemicroorganisms |
| CFU: | Colony-formingunits |
| NUT: | Nephelometricunitsofturbidity |
| ASAS: | Anionoactivesurface-activesubstances |
| SSAS: | Syntheticsurface-activesubstances |
| TCB: | Thermostablecolibacillusbacteria. |