Water and health in Europe: an overview

There are many pressures on Europe’s water resources. They arise from industrialisation, the intensification of agriculture, and changes in populations (not just growth, but also the move from rural to urban habitats). Universal access to safe drinking water and sanitation is the most fundamental principle necessary to ensure the health and wealth of nations, and there is understandable concern that this could be prejudiced by the unsustainable use and management of water.

Surface and underground water sources have a finite (and sometimes small) capacity for renewal, and societal pressures have an impact on the quality and quantity of the resource. It is essential that both quality and quantity are managed together and that this management is integrated into long term planning and policy development.

Many parts of Europe are currently well provided with fresh water but it is unevenly distributed between and within countries, and there are shortages in a number of areas. A wide range of chemicals has been found in the water but evidence of their impact on health has often been difficult to identify. Problems of significant chemical contamination are often localised and may arise from natural geological conditions as well as from human activities. Not all households in Europe are supplied with piped drinking water; rural populations in the east of the continent are less well served. Treatment and disinfection of drinking water occurs inconsistently across the continent, and in areas where economic and political changes have led to a deterioration of infrastructure, a number of outbreaks of waterborne disease have occurred. Inadequate sewerage systems also pose a threat to health.

Summary points

• Much remains to be done to improve the reliability and comparability of European data on water safety

• Water shortages contribute to the most urgent health problem facing some European countries

• Progress has been made in dealing with pollution from plant nutrients (chiefly phosphorus from human waste) but the influence of nitrogen (chiefly from agriculture) remains a pan-European problem

• In some countries large numbers of people drink water that contains higher concentrations of nitrates than are safe; generally, rural populations are more at risk than urban

• Providing continuous access to safe drinking water is fundamental to protecting populations from microbiological diseases

• Over 11 years in 18 European countries, more than 2.5 million cases of gastrointestinal and other waterborne diseases were reported; 2% were linked to drinking water

There have been major changes in water management in Europe, with moves to integrate environmental policies into other sectors and to initiate greater coordination between industry, agriculture, and society. The European Commission’s proposed Water Framework Directive (Com (97) 4 final),which emphasises not only management at catchment level but also the integration of quality and quantity aspects of water management, will be an important advance. In addition, the World Health Organisation’s Regional Office for Europe in partnership with the United Nations and the Economic Commission for Europehas prepared a new protocol for the 1992 Convention on the Protection and Use of Transboundary Watercourses and International Lakes¹; the new protocol requires signatories to take account of human health, water resources, and sustainable development.

Methodology

This overview draws on the most recent publications of the European Environment Agency and the WHO and aims to highlight their key findings. A pan-European assessment of the state of the environment was published in 1995² and updated in 1998.³ More specifically, the European Topic Centre on Inland Waters, which is an international group of experts led by the Water Research Centre in the United Kingdom, has published detailed reports on rivers and lakes,⁴ groundwater,⁵ and the sectoral use of water.⁶

In addition, representatives of all member states of the WHO’s European Region were invited to complete a questionnaire on drinking water quality and waterborne diseases and to provide national reports on these issuesif they were available. Responses were processed by the centre on inland waters in cooperation with experts from the WHO’s regional offices. A document was then produced jointly by the European Environment Agency and the WHO for the third ministerial conference on environment and health, held in London on 16 June 1999.⁶

Distribution of freshwater resources

Freshwater resources are continuously replenished by natural processes. About 65% of precipitation on land returns quickly to the atmosphere by evaporation and transpiration. The remainder (runoff) replenishes surface and underground water as it flows to the sea. The amount of annual runoff is used as an indicator of available water, and annual amounts range from over 3000 mm in western Norway to less than 25 mm in southern and central Spain. To maintain sustainability, resources must be managed to ensure that the rate of use does not exceed the rate of renewal. The amount of fresh water used annually as a percentage of total renewable water resources is shown in figure 1; most European countries have sufficient resources. It is generally recognised that annual use which exceeds 30% of the total renewable water resources is unsustainable in the long term.⁷ Water resources are reported to be insufficient in Moldova, southern Ukraine, the lower reaches of the River Volga, the Caspian lowlands, and parts of Kazakhstan.⁸

Figure 1.

 Amount of fresh water used as percentage of total renewable water resources in Europe

Threats to water quality

Human waste

Although having large numbers of people living together in close proximity simplifies the collection of waste water, disposal of the large amounts of solid and liquid waste generated can compromise the quality of the body of water that receives the waste. Conventional mechanical (primary) and biological (secondary) treatment processes do not remove the plant nutrients (nitrogen and phosphorus) that often cause excessive growth of algae in fresh and coastal waters. The number of micro-organisms discharged (even though 90-99% may be removed) usually renders the receiving water unfit for recreational purposes. Chemical (tertiary) treatment, primarily to remove phosphorus, has been used in Finland and Sweden since the 1970s and is becoming more common in western and northern Europe, largely to meet the requirements of the European Commission’s Urban Waste Water Treatment Directive (1/271/EEC). The increasing use of phosphate free detergents in a number of western European countries is also helping to lessen the impact of excessive plant nutrients. However, the use of chemical treatment and the availability of phosphate free detergents are uncommon in central and eastern European countries.

Agriculture

Concerns about the impact of agriculture on water quality are usually related to issues of the leaching and runoff of chemicals that have been applied to crops and soil. Contamination of water by microbiological pathogens (such as enteropathogenic strains of Escherichia coli and the protozoan cryptosporidium) from farm wastes and animal slurries is also a concern. The intensification of agriculture in many areas has resulted in large quantities of inorganic nitrate fertilisers being applied to arable land. These fertilisers compound the problems of excessive plant nutrients, since nitrogen is particularly a problem in coastal waters. The presence of nitrates in surface and groundwater is a problem if the water is to be used as drinking water since limits on the permissible concentrations of nitrates are applied. Countries with a high population density or that use intensive agricultural practices, or both, use greater amounts of nitrate fertiliserscompared with countries with low population densities or less intensive agriculture, or both. For example, in 1994 the use of nitrate fertilisers was about 190 kg/ha in the Netherlands, 40 kg/ha in Greece, and 5 kg/ha in Iceland.

Access to safe water

Residents in the towns and cities of Europe are generally well supplied with connections to water. In many countries, 100% of the urban population has a home connection to mains drinking water. Because of logistical, political, and cost issues, rural populations are less likely to be connected to mains water supplies. For example, in Italy 78% of the population in the north east is connected to a mains supply but only 27% of the population of the Italian islands is similarly served. The homes of as few as 5% and 12% of the rural populations of Turkmenistan and Ukraine, respectively, are connected to water.

Continuity of drinking water supplies

Most public and private water utilities in the European Union and many public suppliers in central and eastern Europe are able to maintain a continuous supply of drinking water, but in some countries interruptions are normal. Interruptions may occur because there is a shortage of water (which is often seasonal), demand exceeds supply, there is leakage, or a discontinuous supply of electricity prevents pumping. Regardless of the reason, when water is not provided continuously there are implications for health. In the outlying suburban areas of Tirana, Albania, 78% of the population has water supplied for 2-3 hours per day and 33% have water for only 1 hour. No residual chlorine was found in 54% of samples supplying 21% of the population of outlying areas of Tirana.¹ In Romania there are many regions where the supply is discontinuous, and some interruptions exceed 12 hours per day.¹

Treatment of drinking water

The type and degree of treatment required to make water wholesome differs depending on the quality of the source. Good quality groundwater often requires no treatment other than disinfection, but other sources may be contaminated with nitrates, pesticides, solvents, or pathogens. Satisfactory treatment and maintenance of the distribution system are compromised in many central and eastern European states by financial restrictions (box).

Constraints affecting supply of drinking water in Europe¹

Albania: Financial constraints; organisational, and technical problems, and problems with human resources reported; old supply systems suffering corrosion; manual chlorination equipment inadequate

Belgium (Walloonia): Financial constraints on water treatment (cost/m³) in areas where small numbers of people are connected to many small sources

Croatia: Financial constraints

Czech Republic: Financial constraints prevent the use of the best available technology

Estonia: Financial constraints

France: Financial constraints, particularly in small communities with fewer than 100 inhabitants

Greece: Financial constraints

Lithuania: Financial constraints; equipment and chemicals unavailable

Malta: Financial constraints

Moldova: Financial constraints and poor availability of equipment

Romania: Personnel have not been trained; financial considerations limit improvements in equipment for water treatment and chlorination and ability to correct the overloading of water treatment capacities

Slovenia: Organisational difficulties and lack of workers; financial constraints have resulted in a lack of sophisticated treatment plants

Sweden: Number of people working on waterworks has been reduced

Health impacts

Non-microbiological contaminants

Lead—

Concerns about the potential health effects of dissolved lead have resulted in considerable efforts being made to reduce concentrations in drinking water. Raised lead concentrations occur naturally in only a few areas, for example, in the River Debet in Armenia. The usual source of lead contamination is pipes used in plumbing, and replacement of these is the only long term strategy. A reduction in the capacity of water to dissolve lead can be achieved by dosing with orthophosphate or by adjusting the pH from acid to alkaline, or both.

Arsenic—

Arsenic isa known human carcinogen, which is associated with skin cancer. It occurs naturally in high concentrations in southeastern Hungary and along the border with Romania, where an estimated 400 000 people were exposed in 1981 to concentrations exceeding the WHO’s standard.⁹ Chemical precipitation technology is now used to remove arsenic from drinking water in areas where there is no alternative supply. In 1995 it was estimated that the number of people exposed to arsenic in Romania and southeastern Hungary had been reduced to 20 000.¹

Fluoride—

Most countries do not keep records of fluorosis. The WHO’s guideline on exposure is 1.5mg fluoride/l, and most countries do not exceed this. However, in Estonia 25-35% of samples of drinking water analysed since 1988exceeded this standard and 0.7% of the population had been exposed to these concentrations.¹ In Sweden, where fluoride occurs naturally, an estimated 2.4% of the population is exposed to concentrations higher than the standard.¹ An estimated 35% of the population of Moldova is also exposed to high concentrations of fluoride.¹

European countries reporting high nitrate concentrations in drinking water

Austria	France
Belgium	Germany	Slovakia
Croatia	Malta	Slovenia
Czech Republic	Moldova	Turkey
England	Netherlands	Ukraine

Nitrates (and nitrites)—

Many European countries report high concentrations of nitrates in their drinking water (box). Nitrate can be reduced to nitrite in the body and may cause juvenile methaemoglobinaemia. Few countries keep records of this disease, and most reported cases are associated with well water, which often comes from shallow wells affected by agricultural activities. Reported incidences of methaemoglobinaemiaper 100 000 population are 0.26 in Hungary, 0.56 in Slovakia, 0.74 in Romania, and 1.26 in Albania.¹ The vulnerability of private supplies to increased concentrations of nitrates has been shown in Lithuania (fig 2).¹ It is estimated that one third of the population of Europe is exposed to nitrate concentrations higher than the WHO’s standard.

Figure 2.

 Comparison of concentrations of nitrate exceeding national standards in public and private supplies of drinking water in Lithuania, 1986-96. From 1986 to 1993, the standard was 45 mg/l, from 1994 to 1996 standard was 50 mg/l

Microbiological agents

Data on waterborne diseases or outbreaks are often incomplete and inconsistent. Recorded cases of disease may have resulted from a number of infection routes not just from water. Tourists who contract diseases (particularly enteric) while on holiday add significantly to the number of reported cases. For the period 1986-96, surveillance data from 18 European countries identified a total of more than 2.5 million cases of gastrointestinal and other possibly waterborne diseases, of which 2% were linked to drinking water.¹ During the 11 year surveillance, a total of 778 outbreaks of waterborne disease were reported from 19 European countries (table). In many cases the aetiological agent could be identified. Fifty six per cent of outbreaks occurred in rural areas and 44% in urban. Networked public water supplies were associated with 36% of the outbreaks, individual water systems with 18%, and public standpipes with 6%. The supplies associated with the remainder of outbreaks (40%) were unspecified or the outbreaks were associated with recreational bodies of water. An average of 220 people (range 2-3500) were involved in each outbreak. During the 11 years, no outbreaks of waterborne disease were reported in Germany, Lithuania, or Norway. Spain reported 208 outbreaks, Malta 162, and Sweden 53. These differences probably reflect differences in the detection, investigation, and reporting of outbreaks rather than the actual frequency.

Long term prospects

Although some progress has been made over the past decade, coordinated efforts are still needed to ensure that Europe’s population is supplied with clean drinking water and has access to safe water for recreational activities. The aquatic environment must also be maintained in terms of its chemical and biological quality. One particular problem that has been experienced in gaining access to the chain of information on the monitoring, analysis, and reporting of data that exists in virtually every country is the need to improve the reliability and comparability of data that are being produced to support the assessment and development of water policies. This is being tackled by the European Environment Agency and other international bodies, and until a pan-European reporting network is in place there will remain doubt and confusion.

Figure.

ROBERT BROOK/ENVIRONMENTAL IMAGES

Conventional mechanical and biological treatment processes do not remove the plant nutrients (nitrogen and phosphorus) that often cause excessive growth of algae in fresh and coastal waters. The number of micro-organisms discharged usually renders the receiving water unfit for recreational purposes

Table.

Reported outbreaks of waterborne diseases associated with drinking water and bodies of water used for recreational purposes in 19 European countries, 1986-96. Information available for cumulative total of 198 surveillance years^*

Country	Disease (No of outbreaks)	Total No of outbreaks	No of cases (No of outbreaks for which details were available)
Albania	Amoebic dysentery (5), typhoid fever (5), cholera (4)	14	59 (3)
Croatia†	Bacterial dysentery (14), gastroenteritis (6), hepatitis A (4), typhoid fever (4), cryptosporidiosis (1)	29	1 931 (31)
Czech Republic‡	Gastroenteritis (15), bacterial dysentery (2), hepatitis A (1)	18	76 (3)
England and Wales	Cryptosporidiosis (13), gastroenteritis (6), giardiasis (1)	20	2 810 (14)
Estonia	Bacterial dysentery (7), hepatitis A (5)	12	1 010 (12)
Germany	0	0	0
Greece	Bacterial dysentery (1), typhoid fever (1)	2	16 (1)
Hungary§	Bacterial dysentery (17), gastroenteritis (6), salmonellosis (4)	27	4 884 (27)
Iceland	Bacterial dysentery (1)	1	10 (1)
Latvia	Hepatitis A (1)	1	863 (1)
Lithuania¶	0	0	0
Malta	Gastroenteritis (152), bacterial dysentery (4), hepatitis A (4), giardiasis (1), typhoid fever (1)	162	19 (6)
Norway	0	0	0
Romania	Bacterial dysentery (36), gastroenteritis (8), hepatitis A (8), cholera (3), typhoid fever (1), methaemoglobinaemia (1)	57	745 (1)
Slovakia	Bacterial dysentery (30), gastroenteritis (21), hepatitis A (8), typhoid fever (2),	61	5 173 (61)
Slovenia	Gastroenteritis (33), bacterial dysentery (8), hepatitis A (2), amoebic dysentery (1), giardiasis (1)	45	NA
Spain	Gastroenteritis (97), bacterial dysentery (47), hepatitis A (28), typhoid fever (27), giardiasis (7), cryptosporidiosis (1), unspecified (1)	208	NA
Sweden**	Gastroenteritis (36), disease caused by Campylobacter spp (8), Norwalk-like virus (4), giardiasis (4), cryptosporidiosis (1), amoebic dysentery (1), disease caused by Aeromonas spp (1)	55	27 074 (47)
Federal Republic of Yugoslavia†	Gastroenteritis (30), bacterial dysentery (24), hepatitis A (10), typhoid fever (4)	68	10 112 (69)
Total	Gastroenteritis (410), bacterial dysentery (191), hepatitis A (71), typhoid fever (45), cryptosporidiosis (16), giardiasis (14), disease caused by Campylobacter spp (8), amoebic dysentery (7), cholera (7), Norwalk-like virus (4), salmonellosis (4), disease caused by Aeromonas spp (1), methaemoglobinaemia (1), unspecified (1)	780	54 782 (277)

NA=not available. 

^*For the years 1986-96, Andorra, Austria, Belgium, Moldova, Monaco, and Liechtenstein did not keep records of waterborne diseases or outbreaks of waterborne disease; Switzerland did not provide data. ^†Discrepant data were provided in different sections of questionnaire. ^‡One year of reporting only. 

^§Outbreaks associated with drinking water (n=12) and recreational water (n=15). ^¶Ten years of reporting only. 

^**In one outbreak Campylobacter spp, Cryptosporidium spp, and Giardia lamblia were identified as the aetiologic agents. 

Editorials by Brundtland and Pershagen