Paris: More than a fifth of deaths in a
district of Bangladesh were caused by the country`s notorious
problem of arsenic-tainted well water, and even relatively low
exposure to the poison was not risk-free, The Lancet reported
By some estimates, between 35 and 77 million people have
been chronically exposed to arsenic-contaminated water as a
result of a catastrophically misguided campaign in the 1970s.
Millions of tube wells were drilled in the aim of
providing villagers with clean, germ-free water. By tragic
irony, many wells were dug into shallow layers that were
heavily laced with naturally-occurring arsenic.
Several investigations have highlighted the health danger
from this water, but they have been questioned on
These probes provided an overall snapshot but not an
individual one. In other words, they failed to explain how
much of the tainted water a person may have drunk and what
level of contamination was enough to cause sickness.
Seeking to find out, doctors assessed 11,746 people aged
18 to 75 in Araihazar in the Dhaka administrative division.
The physicians checked the volunteers` overall health and
took blood and urine samples every two years. They also took
samples of the local well water to monitor for arsenic levels.
After six years, 407 deaths had occurred from all causes,
21 percent of which could be attributed to arsenic
concentrations above the UN`s recommended threshold. Of deaths
linked to chronic disease, 24 per cent were associated with
exposure to the poison at such levels.
The death rate rose in line with the exposure.
Compared to those exposed to the lowest arsenic levels
(less than 10 microgrammes of arsenic per litre of water),
those with levels of 10-50 microgrammes had a 34 per cent
higher risk of death, and those with the highest level
(between 150 and 864 microgrammes) a 64-per cent higher risk.
Given the long-term effect of arsenic, taking a temporary
break from exposure was no solution, for the risk of death
remained the same, the researchers found.
Chronic exposure to arsenic is linked with cancers of the
liver, kidney, bladders and skin, as well as heart disease.
The UN`s World Health Organisation (WHO) has called
Bangladesh`s arsenic crisis "the largest mass poisoning of a
population in history."