West Bengal || Bangladesh
Middle Ganga Plain, Bihar ||
FIELD TESTING KITS FOR ARSENIC: HOW EFFECTIVE ARE THE MILLION-DOLLAR PROJECTS?
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.
COMMENTS ON THE REPORT
Action Research Report UNICEF/DPHE/ BRAC Arsenic Testing of Newly Installed TubewellsQuality Control on Field Kit Analyses
(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.
(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]