Talk:Arsenic contamination of groundwater

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[edit] Role of bacterial reduction

Bacterial reduction and high arsenic levels in groundwater is interesting, describing how bacteria can reduce adsorption (on metal oxides in the soil) and increase solubility of arsenic. However, I'm not sure if it's notable, and accepted, or speculative, so I won't put it in unless there's more info about this (citations elsewhere, other articles/pages...). --Singkong2005 09:49, 31 May 2006 (UTC)

Yes, the site you have is based on: Islam, FS, Gault, AG, Boothman, C, Polya, DA, Charnock, JM, Chatterjee, D, Lloyd, JR, Role of Metal-reducing Bacteria in Arsenic Release from Bengal Delta Sediments, Nature 430 (6995), p68-71, 2004. This paper has been cited 86 times in the web of science. it is apparent that quite few studies are being done now, reaching the conclusion that microbiological effects are significant.

[edit] Testing arsenic levels?

Is there a practical low cost way to test water for arsenic? See also where the question is posed at Appropedia:Category:Water#Testing for arsenic? --Chriswaterguy talk 02:08, 15 February 2007 (UTC)

The most effective way is the colorimetric tests such as the Wagtech Arsenator. They use something like zinc powder or sodium borohydride to reduce the arsenic in water to arsine, which is volatile. The arsine gas is reacted on a mercuric bromide strip which changes colour. If a spectrometer is used to measure the colour change, the kit is quantitiative down to 2 - 5 ppb. The kit is quite expensive costing $ 1800 in 2004, which apparently left some people sceptical about its use in the third world (www.downtoearth.org.in/full6.asp?foldername=20040630&filename=news&sec_id=4&sid=37). The kit was reviewed by a group commission by UNICEF: it was given almost top marks, i.e. they reckon it works very well (www.wagtech.co.uk/UserFiles/File/Water%20Cat/ArsenatorEvaluation.pdf accessed 2008).

Research efforts are being pursued for electrochemical technique. Although it is cheap to implement and high sensitive (<0.1 ppb in some cases) some aspects need to be improved. With electrochemical techniques the electrode sensor needs to be carefully maintained to keep good performance. Which may involve some esoteric procedures which most people would find difficult. MTI produces the PVD6000 which detects arsenic and other metals, but it is large and more expensive than the Arsenator. (www.mtidiagnostics.com/pdv6000.html)

[edit] Effects of contamination

This section was misnamed and poorly written. If I were an English teacher, I would give the student an F.

• The story of the arsenic contamination of the groundwater in Bangladesh is a tragic one. Diarrheal diseases have long plagued the developing world as a major cause of death, especially in children. Prior to the 1970s, Bangladesh had one of the highest infant mortality rates in the world.

This section begins by saying there was a lot of suffering. Then it will go on to say that they dug wells, which was good (!) but then arsenic was found in the water.

It does not say how many people died or got sick as a result of the arsenic contamination. It only says that one mortality rate went down. Does this mean arsenic is good? I don't think that was the point. --Uncle Ed (talk) 02:15, 13 December 2007 (UTC)