1. Water Scarcity and Global Health
James L. Regens
University of Oklahoma Health Sciences Center
Environmental and Occupational Health Council Association of Schools of Public Health
Environmental Health Conference 2009
June 12-14, 2009

2. Overview Availability of Water Resources
Availability of Water Resources
Factors Influencing Water Scarcity
Impacts on Global Health

3. Imagine being unable to turn on the tap when you get thirsty
Now, imagine having to carry water for hours each day to have water to drink
Or, imagine pinching your nose as you drink to avoid the water’s foul odor
And, imagine the real possibility that taking a drink of water exposes you to disease

4. Annual Water Withdrawals
(m3 per capita)
Source: computed from World Bank data

5. Annual Renewable Water Resources
(m3 per capita)
Source: computed from World Bank data

6. ©IWMI, 2001
The threshold for ‘water stress’ is a per capita availability of 1700m3 of water for annual consumption
For water scarcity the threshold is 1000m3 of water for annual consumption

7.
40% of world’s population (3B people) will live in countries classified as water stressed by hydrologists by 2015
Even though 2.4B people got access to safe drinking water for first time during 1990s, estimated 1.7B people still lack safe drinking water

8. Aral Sea (Central Asia) has 60% less water than 1975
Aral Sea (Central Asia) has 60% less water than 1975
Lake Chad (West Africa) is 1/20th its 1970s size
A number of major rivers around the world including the Colorado, Rio Grande, Indus, and Yangtze no longer reach the sea consistently

9. Factors Influencing Water Scarcity
Hydrologic Cycle
Population Growth
Poverty
Use Patterns
Contamination

10. World population increased 300% in 20th century and use of water increased 700%
Since 1950 the world population has doubled but water consumption has increased six-fold
Water use will increase 50% over 2005 level by 2035
Approximately 2M tons of human waste is released annually into rivers and streams around the globe

11. Impacts on Global Health
About 1.8M people, mostly children, die annually from diarrhea and related diseases with many deaths preventable if water were not contaminated
The combination of safe drinking water, adequate sanitation and good hygiene can reduce the number of deaths caused by diarrhoeal diseases by an average of 65%
The simple act of washing hands with soap and water can reduce diarrhoeal diseases by over 40%

12. In particular, there can be damage to the head, neck and spine.
In many countries children, particularly girls as young as 10 years old, may take the main responsibility for drawing and carrying the family's water.
The size of the water container may vary with the size of the child, but each liter of water carried weighs 1kg and may need to be carried up to three or four miles
Carrying such heavy weights is damaging in the long term for adult women, and for girls there are even more serious implications given their physical immaturity
In particular, there can be damage to the head, neck and spine.
In extreme cases deformity of the spine can lead to problems in pregnancy and childbirth

13. Malnourished children are more vulnerable to disease, especially diarrhea, pneumonia, measles and malaria. These four diseases, plus malnutrition, account for seven out of ten childhood deaths in developing countries. For example in Zambia, one in five children dies before their fifth birthday.
A lack of water also means that children cannot wash often enough and suffer from diseases as a result. These include skin diseases like scabies and eye infections such as trachoma, the largest cause of preventable blindness in the developing world by regularly washing the face, hands, and eyes.

14. Cholera, a bacteria that lasts up to 3 weeks in soil, is spread by contaminated water and food and occasionally by person to person contact. Sudden large outbreaks usually are due to a contaminated water supply.
Bacillary dysentery caused by exposure to Shigella bacteria from contaminated drinking water, food , or flies is contagious and more severe than amoebic dysentery. Approximately 140M people are infected annually causing about 300K deaths, mostly among children under the age of five.
Typhoid fever is contracted when people drink water or eat food contaminated by Salmonella typhi bacteria found in human waste. It affects 17M people worldwide annually, with approximately 600K deaths. Typhoid fever has been virtually eliminated in developed countries.

15. Bilharzia, caused by a small flat worm in the veins of pelvic organs, infects > 200M people in 74 countries and causes 20K deaths/year. Eggs are excreted when people go to the toilet. If the eggs reach a lake or stream to hatch into larva which are eaten by snails, the larva eventually are excreted into the stream or lake where they can infect new people.
Guinea worm, a long worm (≤ 1m) that lives under the skin, enters through contaminated water and can be spread when infected skin is submerged in water, allowing larvae back into water. The number of cases has fallen by 97% from 3.5M to 150K since 1990.
cartercenter.com

16. Malaria causes more that 300M acute illnesses and over 1M deaths annually
Developing safe drinking water supplies and ensuring the environment around water supplies and dwellings is clean reduces larval habitats

17. Key Internet Sites World Health Organization (http://www.who.int/)
Consultative Group on International Agricultural Research (CGIAR) (
Desert Research Institute (
Global Water Policy Project (
International Arid Lands Consortium (
International Center for Agricultural Research in Dry Areas (
International Institute for Sustainable Development (
Nature Conservancy (
United Nations Environment Programme (
United Nations Food & Agriculture Organization (
United States Geological Survey (
World Bank (