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WHO issues revised
drinking water guidelines to help prevent water-related outbreaks and
disease
21 SEPTEMBER 2004 |
MARRAKECH/GENEVA -- Ensuring drinking water is safe is a challenge in every
part of the world, from water piped into people's homes, to rural wells and
water provided to refugee camps in an emergency. Contamination of drinking
water is too often detected only after a health crisis, when people have
fallen ill or died as a result of drinking unsafe water. Today, WHO is
releasing new recommendations which will help pre-empt drinking water
contamination.
WHO advises national
and local drinking water regulators, and the enterprises and organizations
which actually provide drinking water to five billion people around the
world, that the challenge of providing safe drinking water is growing. WHO's
updated Guidelines for Drinking-water Quality (GDWQ) will help regulators
and water service providers the world over maintain and improve the quality
of their drinking water.
“This is an extremely
important change in orientation from a public health point of view. The
revised Guidelines will allow public health management to focus on
prevention of microbial and chemical contamination of water supplies,” said
Dr Kerstin Leitner, WHO Assistant Director-General for Sustainable
Development and Healthy Environments. "And they have as much applicability
whether we are talking about an urban drinking water system in North
America, or protected wells in the developing world. This new approach
exhorts all parties working on drinking water provision and control to act
in such a way that outbreaks of water-borne diseases can be further
reduced."
Traditionally,
drinking water regulations have emphasised testing water samples for levels
of chemical and biological contaminants. Relying on this approach means that
problems are detected long after water is consumed - a remedial rather than
preventive approach.
Outbreaks due to
microbes in drinking water can affect hundreds of thousands of people. In
recent years, communities large and small in some of the world's most
developed countries have been affected by contaminated drinking water. In
Canada, disease outbreaks due to E.coli O157 and Campylobacter,
or Cryptosporidium in the United States, Japan and France as recently as
this month, show what can happen if vigilance is not maintained.
The Hepatitis E
outbreak currently sweeping through internally-displaced-persons camps in
Darfur, Sudan and refugee camps in neighbouring Chad is one example of how
water-borne disease affects poor and disadvantaged populations. These new
guidelines on drinking-water quality include new guidance on their
application in specific settings such as emergencies and disasters.
The updated
Guidelines represent a paradigm shift in advice on how to manage the
provision of drinking water, both in the developed and developing world, in
large urban settings and in the rural areas or villages. Henceforth,
according to the revised GDWQ, the recommended approach for regulators and
operators is to manage drinking water quality in a holistic, systematic
fashion from source to tap. This includes ensuring water reservoirs, or,
local wells, aren't at risk of contamination from human and animal waste, to
checking basics like the regular changing of water filters.
"This third edition
of the WHO Guidelines for Drinking-water Quality is the most significant
water-related public health development since the introduction of chlorine.
The Guidelines' requirement for drinking water safety plans should be
incorporated in regulations across the world," says Dr Michael Rouse,
President of the International Water Association (IWA).
The new edition has
reviewed and revised the recommended values for chemical limits in drinking
water in line with the latest scientific evidence. The GDWQ reconfirm
guideline values for over 100 chemicals. Because routine monitoring for all
of the chemicals is not possible, the guidelines set out practical
approaches to 'rule out' some chemicals and to prioritize others using
readily available information.
In the accompanying
annex, examples from around the world show how much more of an impact
prevention rather than response can have in maintaining drinking-water
quality.
Annex
Africa
21 SEPTEMBER 2004 |
MARRAKECH/GENEVA -- The latest edition of the GDWQ considers the application
of household water treatment and safe storage technologies, which is
becoming increasingly relevant with 1.1 billion people in rural and urban
areas still relying on unsafe drinking water from rivers, lakes, and open
wells. In Sub-Saharan Africa, underground water may have high mineral or
chemical content, such as arsenic and particularly high fluoride levels. In
some districts of Kenya, South Africa, Tanzania and Uganda, for example,
fluoride levels in underground water ranged up to 25 mg/litre - far above
the 1.5 mg/litre limit value recommended by the GDWQ. In those countries,
populations suffer from dental and severe skeletal fluorosis.
Vulnerable
populations cannot afford to wait for the ultimate goal of clean, piped
water. Increasingly, water service providers are recognizing the value of,
seeking guidance about, and implementing point-of-use interventions. In one
example, a recent study conducted among 400 households in a Malawian refugee
camp indicated that using a water container with a cover and a spout
significantly decreased contamination of water and resulted in 31% fewer
cases of diarrhoeal disease in children under five.
WHO Regional contact
for Water and Sanitation in Africa: Dr Ahmed Nejjar, Environmental Health
Officer, Tel: (+47) 241 39271, Email:
nejjars@afro.who.int
North America
In recent years in
Walkerton and North Battleford, Canada, disease outbreaks due to E.coli O157
and Campylobacter, or, in the United States, to Cryptosporidium have
occurred. As recently as this month, contamination of drinking well water in
the U.S state of Ohio by E.coli was being reported. In some cases there have
been hundreds of thousands of cases of illness because of these microbes in
drinking water, showing what can happen when there is not preventive
management of drinking water quality. In response to these outbreaks,
regulatory authorities have shifted towards a more preventive approach,
instigating for example the surface water treatment rule in the USA.
WHO Regional contact
for Water and Sanitation in North America: Mr Luiz Augusto Cassanha Galvão,
Manager, Sustainable Development and Environmental Health Area, WHO Regional
Office for the Americas of the World Health Organization, Tel:(+1)(202) 974
3156, Email: galvaolu@paho.org
Asia
Problems of
naturally-occurring arsenic in drinking water in Bangladesh continue to
attract much concern, especially because of the scale of the affected
population. Some 35 million people in that country alone consume water
containing elevated levels of arsenic. Other affected countries include
India, China, Myanmar, Viet Nam, Laos and Cambodia.
In China, elevated
fluoride in drinking water causes over 26 million people to suffer from
dental fluorosis and is thought to cause one million people to suffer from
skeletal fluorosis. In India, more than 66 million people consume drinking
water with elevated fluoride.
The communities
living in Pacific island countries confront severe logistical challenges in
organizing safe drinking-water supply. A standard "sampling and analysis"
approach to monitoring could never really ensure quality for these isolated
populations. Preventive monitoring is more likely to work. Vulnerable fresh
water lenses on island "atolls" demand holistic management and public
participation if the precious resource is to be sustained.
WHO Regional contact
in South East Asia: Mr Han Heijnen, Regional Advisor, Water, Sanitation &
Health, Tel: (+91) (11) 2337 0804 26641/2, Email:
heijnenh@whosea.org
WHO Regional contact
in the Western Pacific: Mr Terrence Thompson, Regional Adviser, Tel: (+63)
2-528-9890, Email:
thompsont@wpro.who.int
Eastern Mediterranean Region
The quality of water
supplies in the WHO Eastern Mediterranean region (EMRO) countries does not
always comply with national standards, with serious public health
consequences, including disease outbreaks. Earlier this year, much
publicized outbreak of diarrhoea occurred recently in Hyderabad, Pakistan;
over 4000 patients suffering from acute watery diarrhoea were admitted in
hospitals in May/June 2004.
In most countries,
water scarcity is the general rule, but at the same time, water wastage is
widespread and the available water resources are threatened by salt water
intrusion, pollution, and eutrophication. Hence, over 60% of the world’s
installed desalination capacity is located in the region and the cost to
extend and sustain water supply services is rising. EMRO is receiving
requests for guidance on the minimum amounts of domestic water that should
be supplied for domestic purposes as well as on issues unique to
desalination operations and water quality. On the other hand, water supply
systems operate intermittently in a number of countries, due to the severe
shortages of freshwater, and inadequate maintenance and poor management.
Closer drinking-water quality control is required, since water quality
deterioration in the supply system and in household storage facilities
occurs even where piped water supply is ensured.
WHO Regional contact
in Eastern Mediterranean: Dr Houssain Abouzaid, Coordinator, Healthy
Environment, Tel: +(202)6765028 (operator) and +(202)2795362(direct), Email:
seh@emro.who.int
Western Europe
Disease outbreaks
related to water continue to occur also in the most economically developed
European countries. The main cause of outbreaks is often contamination of
the raw water supply combined with missing or faulty disinfecting
procedures.
- In the fifteen years from 1988 - 2002, Norway recorded 72 outbreaks,
affecting a total of 10 616 persons, due either to contamination and/or
failed disinfection.
- The United Kingdom reported 26 outbreaks of waterborne infectious
intestinal diseases in England and Wales in the period 1992 - 1995 with
the most important case affecting 575 people.
- Important outbreaks occur, for example, in areas with small
unchlorinated supplies (Finland, 463 cases of gastroenteritis in a
population of 8,600; nationally 14 waterborne epidemics in the period 1998
- 1999 with 7 300 cases of illness), or in settings where people gather in
considerable densities (Sweden, 500 people, ski resort; Italy, tourism
area, 344 people).
WHO Regional contact
for Water and Sanitation in Europe: Mr Roger Aertgeerts, Regional Adviser,
Water and Sanitation, Tel: (+39) 06 4877528, Email:
rae@who.it
Eastern Europe and the Commonwealth of
Independent States
Although improvements
are being made in some areas, the burden of water-related diseases remains
significantly higher in the eastern, compared to the western, part of the
European region. The Standardized Death Rate from diarrhoeal diseases for
children under age five per 100 000 fell in the Commonwealth of Independent
States (CIS) from 70.03 in 1993 to 21.58 in 2001 and in the Central Asian
Republics from 176.26 to 44.63. Nevertheless, the burden remains much higher
than in the 15 countries of the EU where the rate was 0.64 in 1993 and
decreased to 0.36 in 2001. A similar picture is shown by viral hepatitis A
incidence per 100 000. In the CIS it fell from 186.76 to 86.28 between 1993
and 2001, in the Central Asian Republics from 395.52 to 142.69. In the
EU-15, the decrease was from 7.61 to 4.71 in the same period. Much,
therefore, still needs to be done, especially in the eastern part of WHO's
European Region, to achieve common, high standards of drinking-water
quality.
WHO Regional contact
for Water and Sanitation in Europe: Mr Roger Aertgeerts, Regional Adviser,
Water and Sanitation, Tel: (+39) 06 4877528, Email:
rae@who.it
Latin America and the Caribbean
Only 24% of the urban
population of Latin America and the Caribbean has some water quality control
surveillance system. In Honduras, Nicaragua, Haiti, Guyana and Bolivia, more
than 50% of the population has access to piped drinking water less than 50%
of the time. Moreover, the population covered with adequate surveillance
systems and water quality control is very limited in the urban areas and
insignificant in the rural areas. The fact that more than one-third of the
deaths in Latin America and the Caribbean of children under five years old
are due to communicable diseases highlights the critical role that provision
of safe and reliable drinking water could play in reducing child mortality.
It is envisaged that the new Guidelines for Drinking-water Quality will
facilitate national and local authorities in the improvement of water
quality at local level.
WHO Regional contact
for Water and Sanitation in Latin America and the Caribbean: Mr Luiz Augusto
Cassanha Galvão, Manager, Sustainable Development and Environmental Health
Area, WHO Regional Office for the Americas of the World Health Organization,
Tel:(+1)(202) 974 3156, Email:
galvaolu@paho.org
National technical
experts available for interviews
21 SEPTEMBER 2004 |
MARRAKECH/GENEVA -- Experts who have been part of the Technical Committee
working on the revision of the Guidelines and who can comment on drinking
water challenges and successes in their countries include:
Australia:
Dr David Cunliffe, Principal Water Quality Adviser, Department of Health,
Tel: (+61) (8) 8226 7153, Email:
David.Cunliffe@health.sa.gov.au
Bangladesh:
Professor M. Feroze Ahmed, Professor of Civil/Environmental Engineering,
Bangladesh University of Engineering and Technology (BUET), Tel:. (+880) 2
966 3593; E-mail: fahmed@ce.buet.ac.bd
Canada:
Ms Michèle Giddings, Manager, Water Quality & Science Division, Health
Canada, Tel: (+1) (613) 952-2594, Email:
Michele_Giddings@hc-sc.gc.ca
Colombia:
Mr Jorge Latorre Montero, Universidad del Valle/Cinara, Facultad de
Ingenieria, Cali, Tel: (+57) (2) 339 3245, Email:
jorgelat@univalle.edu.co
Germany:
Dr Ingrid Chorus, Umweltsbundesamt (Federal Environmental Agency), Tel:
(+49) (30) 8903 - 1346/1305, Email:
ingrid.chorus@uba.de
Japan:
Dr Shou-ichi Kunikane, Director, Department of Water Supply Engineering,
National Institute of Public Health, Tel: (+81) (3) 3441 7504, Email:
kunikane@niph.go.jp
Malaysia:
Dr Suresh Kumar, Associate Professor, Department of Parasitology, Faculty of
Medicine, University of Malaya, Tel: (+60) (3) 7967 54743, Email:
suresh@ummc.edu.my
The
Netherlands: Dr Ana Maria de Roda Husman, Health-Related Water
Microbiology, Rijksinstituut voor Volksgezondheid en Milieu, Bilthoven, Tel:
(+31) (030) 274-4325
Sweden (and
other Nordic countries): Dr Thor-axel Stenström, Swedish Institute
for Infectious Disease Control, Tel: (+46) (8) 4572469, Mobile (+46) (706)
476 047, Email:
thor-axel.stenstrom@smi.ki.se
South Africa:
Professor Willie Grabow, Consultant, Health-Related Water Microbiology,
Pretoria, Tel: + 27 12 361 1973, Email:
wgrabow@icon.co.za
Thailand:
Dr Theechat Boonyakarnkul, Director, Sanitation and Health Impact Assessment
Division, Ministry of Public Health, Tel: 662 590 4342, Email:
tchat@health.moph.go.th
United
Kingdom: Mr John Fawell, Independent consultant on Drinking Water
and Environment. Tel: (+44) (0)162 852 0494, Mobile: (+44) (0)7930 986 169,
Email: john.fawell@johnfawell.co.uk
United
States: Dr Ed Ohanian, Director, Health and Ecological Criteria
Division (MC: 4304T), USEPA US Environmental Protection Agency, Tel: +1 202
566-1117, Email:
ohanian.edward@epamail.epa.gov
For more
information contact:
Gregory Hartl
Telephone: +41 22 791 4458
Email: hartlg@who.int
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