Ganga-Meghna Brahmaputra || West Bengal || Bangladesh || Middle Ganga Plain, Bihar || Uttarpradesh
Jharkhand || North-East Hilly States || Rajnandgaon, Chattisgarh || Behala, Kolkata, WB || As toxicity- Homeopathic Treatment
Effectiveness & Reliability - As Field Testing Kits || Utility Of Treatment Plant
Causes, Effects & Remedies - Groundwater As Calamity || References

Arsenic Poisoning in West Bengal : Field Testing Kits for Arsenic




When none of the five filed kits recommended that the field samples be analysed after a few hours, why did NEERI/WHO collect the water samples and analysed them after bringing them to a regional laboratory? The report also does not mention after how many hours the samples were analysed.

Further, may I ask NEERI/WHO that even if they have measured after bringing the samples to the laboratory, why did they not collect the samples from the affected villages of West Bengal and Bangladesh using 1 ml HCl or 1 ml H2SO4 per liter water and analysed it in a zonal laboratory, when the field kit techniques that are based on "Mercuric bromide stain method or Netelson method" recommends H2SO4 or HCl mixed with water at the beginning followed by other chemicals to generate arsine (Netelson, S. Microtechniques of Clinical Chemistry, 2nd edn. Charles Thomas, Springfield, Illinois, pp 113-19, 1961; Arsenic exposure and health effects edited by: C.O. Abernathy, R.L. Calderon, W.R. Chappell, Chapmann & Hall, 1977, page-21).


Action Research Report UNICEF/DPHE/ BRAC Arsenic Testing of Newly Installed TubewellsQuality Control on Field Kit Analyses

March, 1999

I understand from the UNICEF/DPHE/BRAC report that to make a comparative study of Field Workers’ findings relating to newly installed tubewells, Regional Supervisors went to the site with the same Filed Kits after some time (days/months/year, not clear from the report) to check the results of the Field Workers and could identify 61 tubewells out of 120 the Field Workers measured earlier and analysed them. My enquiry :

(1) Instead of comparing 61 tubewells by Field Supervisor that were measured before ,by Field Workers why the Field Supervisor did not compare these 61 tubewells again by Field Workers followed by Field Supervisors. The reason for this is newly installed tubewell water, if not filtered through milipore filter, may show higher arsenic results (even 50% higher). The invisible arsenic bearing particles may be the reason. With time the particles settle down and variation decreases.
Figure-A shows a study by our group of a newly installed tubewell in West Bengal.

(2) Figure-1 of the report shows the positive correlation between field kit analyses by Field Staff and the Regional Supervisor. I understand that 61 samples were measured. If so, then why only about 22 samples are plotted in Figure-1 Further, if it is known to UNICEF/DPHE/BRAC from WHO-NEERI report, that field kits cannot identify arsenic from contaminated tubewells when arsenic the concentration is between 50 and 200 µg/l, then why was only 1 sample was plotted in Figure-1 in this range? Most of the samples are above 200 µg/l and it is known from WHO-NEERI's report, "99% reliable in identifying groundwater samples from > 200 µg/l."

[Action Research Report UNICEF/DPHE/BRAC Arsenic Testing of newly installed tubewells; Quality Control on Field Kit Analysis, March, 1999, page-4]