This Chapman Conference is intended to review a decade of Earth science research on the mechanism(s) of arsenic mobilization in groundwater of southern Asia, identify those areas where a consensus has emerged and, in the case of several important open questions that remain, determine what types of experiments or studies are needed.
24.03.2009 - 27.03.2009
Siem Reap, Cambodia
Conference web site at:
Underlying (Bio)Geochemical Processes
- What is the relative timing of release of As and Fe?
- What are the biogeochemical processes responsible for arsenic (and iron) release?
- How important are potential back-reactions – e.g. arsenic adsorption?
- What fuels the biogeochemical process – e.g., plant- vs. animal-derived, or recent vs. ancient, organic matter?
- Are there critical nutrients limiting release of arsenic, and is there a source of these nutrients in arsenic hotspots?
- Can a detailed understanding of microbial populations help with understanding the distribution of As in groundwater?
Role of Hydrogeology and Transport
- How are groundwater arsenic concentrations affected by
surface conditions – e.g. clay or sand soils; agriculture, villages,
ponds or rivers?
- Is arsenic mobilized at a greater rate from certain types of sediments?
- Has the development of paddy fields significantly influenced the pattern of arsenic concentrations in groundwater?
- What will be the consequences of prolonged irrigation of rice paddies with groundwater elevated in arsenic?
Vulnerability of Low-Arsenic Aquifers – Policy Implications
- Is the age of a well since installation relevant and if so, how?
do arsenic concentrations respond to changes in recharge from village
construction, pond construction, shifting agricultural practices?
- Does the release of organic carbon from latrines lead to arsenic enrichments in groundwater?
- How do arsenic concentrations vary with concentrations of other potentially harmful solutes, such as manganese and heavy metals?
- What simple/cheap observations might aid the targeting of low arsenic aquifers?
- Can biogeochemical processes be harnessed to remove arsenic from groundwater in situ and ex situ?
- Do we know enough about the biogeochemistry/microbial ecology of deep wells, and how they will respond to prolonged pumping?
Consensus(?) and Critical Experiments
- What are the similarities and differences between Himalaya
catchments where arsenic is found (or not found) in groundwater in
terms of spatial patterns, organic carbon sources, and land-use
- Are there commonalities between the mechanisms of arsenic release in inland and coastal aquifers?
- Are laboratory studies to identify arsenic-mobilizing microorganisms and the functional genes that they carry useful?
- Can laboratory experiments help us understand processes in situ and inform mitigation strategies?
hydrogeologic methods widely applied in the West to groundwater
contamination problems (3D flow and transport modeling, 3D networks of
pressure transducers, field-scale tracer tests...) be applied to
understand arsenic contamination in poor countries?
- Why have these methods been applied so sparingly?
- What should we as a research community do collectively to project future groundwater levels of arsenic and evaluate long-term solutions?
|November 21,2008||Submission of abstracts |