Groundwater Quality, a health issue?
GEOSS Joint Asia-Africa Water Cycle Symposium

Annette Johnson

Eawag: Swiss Federal Institute of Aquatic Science and Technology

Arsenic
An estimated 140 million people are exposed to arsenic⇒ Via drinking water• Soluble under chemically reducing conditions• Geothermal waters, volcanic ashes⇒ Via food and food preparation• Paddy field rice
• Contaminated water for cooking⇒ Health effects• Dermal lesions• peripheral neuropathy• diabetes mellitus• cancers⇒ WHO recommended guideline• 10 µg/L for drinking waterFluorideAn estimated 200 million people are exposed to fluoride⇒ Via drinking water• Ultramafic rocks, granites, volcanic ashes• Arid conditions⇒ Via food and food preparation> 10 mg/L• Beverages, specialty salts• Local produce from contaminated soils⇒ Health effects• Dental fluorosis

4 - 10 mg/L

• Skeletal fluorosis• Multiple non-skeletal symptoms

1 – 4 mg/L

⇒ WHO guideline• 1.5 mg/L for drinking waterca. 1 mg/L

Arsenic contamination map – World Bank 2006

World Bank, 2005
Amini et al., ES+T 2008aModeling geogenic contamination

Topography
Geology
Soil type

LanduseIrrigation
Wetlands
Discharge
Temperature
Precipitation

Evapotranspiration

Data points
Fluoride: 69’500
Arsenic: 19’500

First generation risk map for arsenic > 10 µg/L

Amini et al., ES+T 2008a

Number of locally affected lives becomes global challenge>50% probability of contaminated groundwater overlain with population density

04.04.2011

Population living in arsenic hazard areas:
754 million (2010 population estimate, SEDAC)
1/3 drinking groundwater? ⇒ about 250 million

7First generation risk map for fluoride > 1.5 mg/L

Amini et al., ES+T 2008b

Number of locally affected lives becomes global challenge>50% probability of contaminated groundwater overlain with population density

04.04.2011

Population living in fluoride hazard areas:
561 million (2010 population estimate, SEDAC)
1/3 drinking groundwater? ⇒ about 200 million

9Needs
Lessons we have learnt:
1)Many countries are struggling to provide drinking water from
improved sources2)There are well known cases where countries are struggling toprovide arsenic- or fluoride- free water
E.g. Bangladesh (As), India (F)1)But many countries may have contamination they still need toaddress
2)There is a need for such prediction maps3)There is a need for information exchange and sharing

10Groundwater Assessment Platform (GAP)
A user-friendly, open-source online platform for water quality information• Upload data
• Data analysis andmodeling• Connect to and initiate
new peer communities• Comprehensive ‘datarights’ management• All of the above• Building community
networks• Visualization• Aggregate statistics• Connection to externaldatabases• Download georef’edinformation• Links• Platform for open
discussion & exchange• Public sharing ofinformation and advice• HUB for networking andconnecting

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Linkages?
We are at the very beginning and there may be opportunities
1)To link to quantitative water resource issues-Alternative water resources-Mapping of water points-etc.
1)To partner with other organisations-Regional hubs to provide water-quality training, data management,
modeling-Mapping o/modelling of other quality issues – e.g. salinity-Long-term hosting of platform

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