Transcript Illinois - Harvard University Department of Physics

The world arsenic
Catastrophe:
University of Illinois
Friday April 7th 2006
Richard Wilson
Mallinckrodt Research Professor of Physics
Harvard University
http://arsenic.ws
http://phys4.harvard.edu/~wilson/arsenic_project_introduction.html
30,000,000 exposed in Bangladesh
above US EPA standard
A catastrophe that makes
Chernobyl look small!
others in:
West Benglal
Nepal
Thailand
Vietnam
Pakistan
How does the world help
Bangladesh?
Three vital items
(1) Make sure measurements of
arsenic and coliform bacteria are
regular and accurate
(2) work with local
community - they must make
decisions and follow up
and
(3) get funds direct to
villagers (avoid sticky fingers
as much as possible)
RELIABLE measurement is crucial
IAEA interlab comparisons
2000 10 labs only 6 ok
2005 11 labs 5 reliable but not
accurate 1 bad
SDDC-Spectrophotometry, Reflectance
Photometry, Electrochemical- Anodic
Stripping Voltammetry (ASV),
Hydride Generation and Graphite Furnace
Atomic Absorption and Fluorescence
Spectroscopy
(HG, GF, AAS/ AFS), and
Total Reflection X-Ray Fluorescence
Spectroscopy (TRXRF)
FIELD kits (Gutzeit method)
Arsine generation and color change
HACH kit works butmany field workers bad
NEED A GOOD LAB IN
EACH UNION
DCH
My recommendation to
the Government of Bangladesh
Find out which (NGO) is
doing a competent job
(Discuss on web, conferences,
WHO etc)
Get money direct to them
Even if not economically the
“best”
doing nothing is expensive
especially in good will.
1998 (DCH conference)
urged immediate action:
(1) Measure every well
Green for OK
Red for don’t use
Encourage well switching
(2) Purify Water at House level
with simple equipment
(3) Encourage deep wells
(below clay layer)
(4) Encourage solutions that
lead to the long term
Labelling wells was
partially successful
30% of people switched wells
but ~10 million people helped!
67% switched when a massive
education campaign
(Columbia-U.Dhaka)
Some wells badly labeled
Perhaps status of wells changed
MY CONCLUSION
BETTER EDUCATION
CAMPAIGN NEEDED
on switching
Uncritical use of Arsenic
Removal Systems (ARS)
May even be
counterproductive.
AN OLD REMEDY
So Moses brought Israel from
the Red Sea, and they went out
into the wilderness of Shur; and
they went three days in the
wilderness and found no water.
And when they came to Marah
they could not drink of the
waters of Marah for they were
bitter. And they murmered
against Moses saying “What
shall we drink?” and he cried
unto the Lord; and the Lord
showed him a tree, which when
he had cast into the waters , the
waters were made sweet”
• In West Bengal several hundred have been
installed.
80% are not functional.
•
(6th report: Jadavpur University)
BUT they seem to work
when there is “backup”
• Sengupta of Bengal
College
• SONO filters near Kushtia
•
DCH tests have not been as
good as hoped
• Also NOT a long term solution
Deep wells have worked
in Dhaka for a long time!
Badly installed wells
could bring water down
from upper aquifer.
BUT 98% likely to work
at least 20 years
Maybe for ever.
Long shot:
Professor Charles Harvey
(MIT) thinks
the problem is pumping
water from anoxic region.
Possible Solution:
Pump concentrated
oxidants into the well.
Works for a week;
tried with massive amounts
of oxidants January 2006.
We will see.
Bangladesh Policy
Use surface water when
possible
Rainwater Collection
Improved (sanitary) Dugwells
Pond Sand Filters
River Sand Filters
We must avoid bacteria
and know we have avoided bacteria
Key is measurement
Measurement Cheapest if a large
number supplied from one unit
January 2000
If you ask villagers to put up with your
measurements of water (Harvey)
and epidemiological studies (Christiani)
you have to do something for them
So we gave DCH a $10,000 check for
new water resources
(about $60,000 by now)
January 2001 we gave them a kit
(University of Surrey) for measuring
coliform bacteria
Then we got Ashok Khosla (New Delhi)
to send his (JAL-TARA) measuring kit
which they used.
POND SAND FILTER
for several hundred people
• Originally built in 2001-2
• this was high in Coliform.
• It was rebuilt with more stages
and by January 2004 low
coliform were measured.
Dhaka Community Hospital
(experts in community health)
has been installing
Sanitary surface “dugwells”
where >80% tubewells contaminated
WHO standards; Covered;
Originally limed,
(note that BRAC and Grameen Bank did not follow
these standards)
now chlorinated (every 3 months)
(now) measured regularly
More recently pumped to tank and
pipeline
to give running water
VERY POPULAR
Capital cost $6/person
• 66 seemed OK in Pabna region.
• (6 now abandoned)
• Checked, limed, tested every 3
months for a year.
• Low arsenic (LOD 3 ppb)
• 0-10 coliform 0 fecal coliform
• But questions were asked by Feroze
and others
• 2005 tests on 10 wells looked bad.
• Maybe they ONLY tested just after
liming. Now they claim chlorinating
every 3 months OK (<10 fc
structures/dl)
• Jabed Yousuf (DCH) is now in
charge of getting measurements
and should have been here but
DHS did not give him a visa
Share
ideas
data
publication
web
• Why the long delay?
• Importance of discussing with
villagers
• U Dhaka questionnaire shows
• People willing to pay 20 X as
much for piped water as for
arsenic free water
Enables larger systems to supply
more villagers
(maintenance spread over more
people)
Piped water system leads
naturally to central system in
the long term
• I suggest piped water is an
imporatant option to suggest to
people independent of where
the water comes from
My recommendation to
the Government of Bangladesh
Find out which (NGO) is
doing a competent job
(Discuss on web, conferences,
WHO etc)
Get money direct to them
Even if not economically the
“best”
doing nothing is expensive
especially in good will.
The whole job can be done
for
ONLY $300 million!
$1 each American
World Bank provided a $50
million 1% loan that Jim
Wolfensohn expected to be
spent with 18 months
and
Kuwait Fund can help
when asked by
governments
Meanwhile please support
the public foundation of
your choice
Dugwell Foundation
http://www.dugwellfoundationusa.org
(Meera Smith)
Arsenic Foundation
http://arsenicfoundation.com
(Richard Wilson)