West Bengal || Bangladesh
Middle Ganga Plain, Bihar ||
FIELD TESTING KITS FOR ARSENIC: HOW EFFECTIVE ARE THE MILLION-DOLLAR PROJECTS?
Field Kit and Health
* It is known that arsenic is one
of the most toxic substances known to man. "We estimate that the
maximum arsenic concentration in the immediate vicinity of the kit
can be more than
35 times TLV of arsenic
from a single experiment with 100 ppb total arsenic in solution. Particularly,
field workers performing a large number of tests in highly affected areas
are exposed to much higher level of arsenic...."
* However another information received from BRAC, Bangladesh, shows
Reliability of the Field Kits for measurement of Fluoride, nitrate, etc. are not questioned as the permissible limit are high (F- 1.5 µg/l, Nitrate - 50 µg/l etc.) and at that level Field Kits work satisfactorily. But for arsenic the maximum permissible limit is 50 µg/l and, because of this low permissible limit, reliability of of Field-Kit is questioned. From the avilable field data it appears that the Field-Kits show satisfactory results (yes/no) when concentration measured is above 200 µg/l of arsenic.
In India and Bangladesh, the present permissible limit of arsenic in drinking water is 50 µg/l and we believe soon it may be reduced to a lower value. The reasons for saying this are (1) WHO guide line value is 10 µg/l; (2) the USA is expected to change its maximum permissible limit; (3) our field data shows that a given concentration of arsenic in drinking water affects people with poor nutrition levels more than those with better nutrition levels, and in the arsenic affected areas of W. Bengal and Bangladesh millions are suffering from malnutrition; (4) adult people of West Bengal and Bangladesh drink on an average 4.0 litre of water per day [Ph.D. Thesis, Status of Arsenic Problem in Two Blocks out of Sixty in Eight Groundwater Arsenic Affected Districts of West Bengal, India; Badal Kumar Mandal, Jadavpur University, Calcutta, India, 1998] when the present WHO guideline value and maximum permissible limit 10 µg/l and 50µg/l have been arrived at on the basis of 2.0 litre of water consumption per day.
Thus for poor nations arsenic in drinking water should be even less than WHO limit.
If government of India and Bangladesh were to recommend the level of arsenic in drinking water to be 10 µg/l, then the data we are going to generate, spending millions of dollars, will not be so useful and we will have to go for sensitive instrumental techniques as we cannot expect to get any reliable data at the 10 µg/l level from the presently available field kits. So it will be a wise decision to select an instrumental technique that can determine 5 µg/l of arsenic in 95% confidence level and instrumrental technique will be much cheaper compared to Field-Kit if large number of samples are analysed, as is going to be the case in W.Bengal and Bangladesh.
Financial support required for five FI-HG-AAS laboratories against UNICEF's
more than 1.0 million US $ Budget for arsenic field testing kit proposal.
Field kit proposal approx. 1.147 million US dollar
5 FI-HG-AAS laboratory 0.377 million US dollar