Drinking water is a primary need for the health of people and the community and has always been linked to the development of life and civilization. Universal access to drinking water and sanitation is a fundamental human right and its protection it is considered a "priority action of the United Nations Organization (UN), of the World Health Organization (WHO), of the European Union and of national policies. Standards, regulations and legislative measures adopted in Italy, as in many other countries , have the objective of ensuring that safe water is available in adequate quantities in every home, school, community and in every production environment, with continuity in the supply and sustainable costs for consumers.
For a "water to be defined as drinkable it must be:
- free from suspended particles (clear and transparent)
these characteristics are defined organoleptic.
Furthermore, it must not contain:
- chemical substances
in quantities that represent a potential health hazard.
On the other hand, some essential elements for health such as, for example, boron, selenium, fluorine, chromium and copper, which the body is unable to produce on its own and must obtain from food, are conveyed through the waters in which they are naturally present (read the Buffalo) together with other mineral salts such as calcium, magnesium, iodine, potassium, also essential for the development of tissues and organs (for example, teeth and bones), for exchanges between cells and for other reactions that produce energy (read the Hoax).
It is therefore important to drink an adequate amount of water (at least 2 liters per day for an adult), especially in hot periods or after having performed an intense physical activity, with strong sweating and loss of fluids and mineral salts.
According to the most recent data from the National Statistical Institute (ISTAT), the volume of water withdrawn for potable use from the supply sources in Italy is equal to a daily quantity of 428 liters per person, the highest in the European Union.
About half (47.9%) of the volume of water withdrawn does not reach the tap, due to network leaks due to old and poorly maintained pipes. The daily supply for drinking use can be quantified in 220 liters per inhabitant.The quality of drinking water and purification processes
The quality of drinking water and purification processes
Water is an essential element for human life but the use of unsafe water can have serious consequences for health. By far the most important danger concerns the possible presence of microbes (bacteria), parasites or viruses, which in advanced countries such as Italy is kept under control both through laboratory analyzes and through treatment and disinfection practices. , on the other hand, a major problem worldwide with more than 2 million cases per year.
As for the chemicals that may be present in water, they can have a natural origin and derive from minerals associated with the geology of water bodies (or aquifers) or come from human productive activities. The latter can pollute the aquifers due to uncontrolled emissions into the environment or be present in the water as trace substances, for example as a consequence of treatments, or released from materials in contact with water (eg pipes).
The quality requirements established for drinking water in our legislation derive from European standards and are based on scientific knowledge that has allowed us to define the quantities for the various chemical substances or microbiological agents which, considering the consumption over the entire life, can be present in water without causing any significant risk to health, according to criteria of maximum precaution (WHO guideline values).
The guide values are defined considering both the ingestion (water drunk directly or assimilated by food during their preparation) and the contact and inhalation that occur using water for domestic hygiene (for example, washing floors and surfaces ) and personal (for example, the shower).
The factors (or parameters) to be controlled are defined on the basis of:
- dangerousness of substances that may be present in the water, for example arsenic or lead
- likelihood of hazardous substances contaminating natural water resources
- probability of dangerous substances contaminating the waters before they arrive at the point where the same waters are used (for example at the tap), during the purification treatments and distribution through the water network
In fact, the water can be drinkable thanks to filtration and disinfection processes that occur naturally during the water cycle or following specific treatments, generally aimed at eliminating possible chemical contamination (removing undesirable substances by passing through filters such as sand, coal, synthetic resins) or by purifying water from microorganisms through disinfection methods, mostly using chlorine, ozone or ultraviolet radiation. Treatments and materials used must meet the requirements of effectiveness in removing contamination efficiently and ensuring safety of the waters.
The disinfection process that has made it possible to prevent numerous diseases due to the presence of bacteria and viruses in the water, in some cases can give rise to the formation of chemical substances (by-products) due to the reaction between the chemical agent used for disinfection, to for example chlorine, and organic matter naturally present in water. However, the risk associated with water treatments can be considered completely under control, because the presence of by-products is constantly monitored.
The origin of the drinking water that flows from the tap can be different:
- shallow waters
- water obtained by eliminating salt from sea water (desalination)
Obviously the treatments to which the waters are subjected to make them drinkable are different and the quality of the same waters often depends on them. Other important factors are the systems through which the water is transported to the point of delivery (usually the meter) and distribution within the buildings. For example, the materials from which the pipes are built can affect the final quality of the water.
For this reason, the safety of drinking water today is based on an evaluation of the entire hydro-drinking system, starting from the water resources used for the supply to the point of supply for the consumer, considering every possible danger and its potential effects. on health.
To the prevention and control system operated by the hydro-drinking operator (or anyone who supplies third parties with water intended for human consumption), an independent control system is added by the competent health authorities in the area and responsible for judging the suitability of water consumption. .
In Italy, the quality of drinking water that reaches the home tap is, in general, very good also because more than 85% comes from groundwater, generally adequately protected from contamination and, therefore, not subject to the treatments to which they are surface waters (from rivers or lakes) are subjected. The national data of the checks on millions of analyzes show a very small number (around 1%) of non-compliance with the standards, in limited areas of the territory.
According to the most recent ISTAT data, many families still do not trust to drink tap water (read the Bufala). The data, however, are improving. The distrust has gone from 40.1% in 2002 to 29.0 % in 2018 with significant territorial differences: from 17.8% in the North-East to 52.0% in the Islands (53.3% and 48.5% respectively in Sicily and Sardinia).
At the origin of the distrust towards tap water there are often interruptions and inefficiencies in the supply, a cloudy appearance, effects due to the state and maintenance of the networks.The regulations
The current regulations regulate the so-called "water intended for human consumption"Which includes not only" drinking water, but also that used for the preparation of food or used for washing practices (domestic or personal hygiene). Furthermore, all the water used by industries for the preparation o the packaging of products intended for human consumption, with the exception of those that have no impact on the hygiene of the product itself (for example, the cooling water of a plant). The rules establish the criteria for the suitability of water for human consumption, taking into account safety levels not only for adults, but also for fragile people such as children or the sick (read the Bufala).
The main rules on the quality and hygiene of water intended for human consumption in Italy are contained in the Legislative Decree of February 2, 2001 n. 31, in implementation of the European Directive 98/83 / EC. These regulations establish, among other things, the safety levels and controls to protect human health with respect to chemical substances (including natural mineral elements), microorganisms and parasites potentially present in the waters (read the Bufala).
The safety parameters established at national level incorporate all the indications defined at European level, also inserting additional parameters considered relevant in our country such as, for example, for chlorite (a by-product that can be formed following some disinfection practices) or vanadium. (natural element present in rocks of volcanic origin) (read the Bufala).
The safety limits for each parameter ("parameter values") are also implemented by the European standard but, in some cases, more stringent national values are adopted, as in the case of trihalomethanes (for example chloroform), which are formed during disinfection with chlorine or with chlorine-based disinfectants, as by-products due to the reaction between the disinfectant and the organic matter contained in the water.
The materials and objects that can be used in plants for water intended for human consumption are the subject of specific legislation, currently under review, to establish a national certification and approval system.
The requirements for the protection of the health of the population in relation to radioactive substances present in water intended for human consumption are regulated by specific legislation, in particular, Legislative Decree 15 February 2016, n. 28.
According to the regulations in force, the hygiene of the water must be ensured up to the final point of consumption, generally the domestic tap, or the industrial refueling point. In the food industry, the maintenance of quality after entry must be controlled and guaranteed by the company itself.The controls
The Italian legislation establishes that the waters, at the point where they are made available for human consumption, comply with the minimum requirements of health and physical, chemical, microbiological and radiological quality. The compliance of water with legal requirements is regulated by the surveillance carried out by water managers and health authorities. In fact, programs of "internal controls" are established, which the manager is required to carry out and "external controls" carried out by the competent local health authority (ASL). of the water that is up to the competent sanitary company.
As part of the regional organization, the competent health authority prepares an annual plan for the frequency of analytical checks. or even to individual users), the frequency of water sampling and the parameters to be checked.
The methods for the analysis of the suitability parameters are established by the Istituto Superiore di Sanità (ISS). In the event that an ASL finds non-conformities in the water, it communicates the results to the supplier and can propose to the mayor, if necessary, any precautionary measures to protect public health.
The control system has recently been significantly strengthened through the introduction, through the Ministerial Decree of 14 June 2017, of the "water safety plans"Which define specific prevention, surveillance and monitoring measures for each" hydro-drinking chain ". In this way, every potential risk factor that can compromise the safety of water is constantly monitored, starting from the environment in which the water resources are taken up to the consumer's tap, including treatments and treatments in the risk analysis. the distribution.
Italy introduced this prevention system conceived in 2004 by the World Health Organization (WHO), and incorporated into the national guidelines drawn up by the Istituto Superiore di Sanità, in advance of European standards.In fact, the obligation to adopt water safety plans is the central element of the new directive on the quality of water intended for human consumption, which is still being finalized today.
This approach makes it possible to face possible "new" risks such as, for example, chemicals that can contaminate surface waters or groundwater following illegal disposal or the eventuality that mineral elements of natural origin are present in the waters at undesirable concentrations. climatic conditions are a critical aspect that must be considered more and more frequently due to their negative effect on the availability and quality of water resources in the environment, but also on the processes of water treatment and distribution.Bibliography
Decree 2 February 2001, n. 31. Implementation of Directive 98/83 / EC relating to the quality of water intended for human consumption (OJ no. 52 of 03-03-2001 - Ordinary Supplement no. 41)
Council Directive 98/83 / EC of 3 November 1998 on the quality of water intended for human consumption (OJ L 330, 5.12.1998, p. 32)In-depth link
Ministry of Health. The standards on the quality of drinking water. Reference legislation
Guidelines on water treatment devices intended for human consumption pursuant to Ministerial Decree 7 February 2012, n. 25, March 20, 2013
Guidelines for information on equipment for the treatment of water intended for human consumption, edited by Colagrossi R, Lucentini L. Rome: Istituto Superiore di Sanità; 2015 (ISTISAN Reports 15/8)
Guidelines for risk assessment and management in water intended for human consumption according to the Water Safety Plan model, edited by Lucentini L, Achene L, Fuscoletti V, Nigro Di Gregorio F, Pettine P. Rome: Istituto Superiore di Sanità; 2014 (ISTISAN Reports 14/21)
Ministry of Health. Drinking water
World Health Organization (WHO). Guidelines for Drinking-water Quality, 2017; fourth edition (incorporating the 1st addendum)