Approaches for System Strengthening and Building Resilience for scaling up drinking water safety in regions with high Arsenic and Fluoride in Groundwater focusing on the global south
Prosun Bhattacharya 1,2,3, Tom van der Voorn 4, Julian Ijumulana 1,2,5
- This short course is free paying the registration for the MEDGEO 2023 Conference. Limited number of participants. Please save your place by sending an email to info@medgeomx.com
- The short course will take place on Sunday, August 6 from 4 to 7 pm.
- The course language will be English.
Inorganic contaminants such as arsenic (As) and fluoride (F-) are detected ubiquitously in the groundwater resources across the globe. Both these elements lead to adverse health impacts following long term ingestion and hence are of concern from public health perspective. Both As as well as F- are mobilized in groundwater from the aquifers through the interaction of groundwater with the constituent solid phases in the aquifers through a number of geochemical triggers under natural geochemical environments. Groundwater basins of wide aerial coverage in regions located in Southeast Asia, Africa and Latin America are more vulnerable where groundwater as drinking water sources among a vast majority of population especially in the rural settings. According to recent estimates, more than 130 million people worldwide potentially are exposed to As at levels above the World Health Organization (WHO) drinking water guideline value of 10 μg/L. Groundwater enriched in fluoride is a widespread problem, and endemic fluorosis is documented from at least 25 countries around the world, and is most prevalent in India, parts of Africa and China affecting a population of several millions where drinking water fluoride concentrations exceed the WHO guideline value of 1.5 mg/L. While As is a proven carcinogen and has a number of carcinogenic and non-carcinogenic effects on human health, fluoride content in drinking water is considered essential below the guideline value. Excessive fluoride has a detrimental effect on human health as excessive fluoride can lead to dental and skeletal fluorosis, manifested through teeth mottling, calcification of ligaments and long term exposure leading to crippling bone deformations and cancers.
A systematic pattern has been observed at a global scale with occurrence of the aquifers with elevated levels of As in groundwaters. Most of these form parts of the foreland sedimentary basins juxtaposed to the orogenic belts. The occurrence of As in the groundwater reflects the original source terrains of sediments deposited in these foreland basins as an effect of crustal evolution in orogenic belts. The mobilization of As in groundwater, is triggered under favorable biogeochemical conditions through a water–rock interactions. The distribution of fluoride is predominantly controlled by water-rock interactions especially in rocks such as granite, amphibolites, pegmatites rich in minerals such as muscovite, biotite, hornblende. The areas traversed by acid volcanic rocks, basic dikes and hornblende gneisses contribute to fluoride-rich soils and solubility in groundwater.
Understanding the geochemical processes leading to the mobilization of the contaminants is a primary requisite for understanding the heterogeneity in the concentrations at both regional and local scales. Community education for strengthening public awareness and the involvement and capacity building of local stakeholders in testing the groundwater quality is important for targeting the safe aquifers for drinking water supplies.
1. KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-114 28 Stockholm, Sweden julianij@kth.se; prosun@kth.se.
2. International Environmental and Health Sciences Consortium (IEHSC).
3. International Society of Groundwater for Sustainable Development, KTH Royal Institute of Technology, Teknikringen 10B, SE-114 28 Stockholm, Sweden.
4. Erasmus University Rotterdam DRIFT, Rotterdam, Netherlands.
5. DAFWAT Research Group, Department of Transportation and Geotechnical Engineering, College of Engineering and Technology, University of Dar es Salaam, Dar es Salaam, Tanzania julian@udsm.ac.tz.
