Increase in diarrheal disease associated with arsenic mitigation in Bangladesh.
BACKGROUND
Millions of households throughout Bangladesh have been exposed to high levels of arsenic (As) causing various deadly diseases by drinking groundwater from shallow tubewells for the past 30 years. Well testing has been the most effective form of mitigation because it has induced massive switching from tubewells that are high (>50 µg/L) in As to neighboring wells that are low in As. A recent study has shown, however, that shallow low-As wells are more likely to be contaminated with the fecal indicator E. coli than shallow high-As wells, suggesting that well switching might lead to an increase in diarrheal disease.


METHODS
Approximately 60,000 episodes of childhood diarrhea were collected monthly by community health workers between 2000 and 2006 in 142 villages of Matlab, Bangladesh. In this cross-sectional study, associations between childhood diarrhea and As levels in tubewell water were evaluated using logistic regression models.


RESULTS
Adjusting for wealth, population density, and flood control by multivariate logistic regression, the model indicates an 11% (95% confidence intervals (CIs) of 4-19%) increase in the likelihood of diarrhea in children drinking from shallow wells with 10-50 µg/L As compared to shallow wells with >50 µg/L As. The same model indicates a 26% (95%CI: 9-42%) increase in diarrhea for children drinking from shallow wells with ≤10 µg/L As compared to shallow wells with >50 µg/L As.


CONCLUSIONS
Children drinking water from shallow low As wells had a higher prevalence of diarrhea than children drinking water from high As wells. This suggests that the health benefits of reducing As exposure may to some extent be countered by an increase in childhood diarrhea.
Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Jianyong
J
Wu
Alexander
A
van Geen
Kazi Matin
KM
Ahmed
Yasuyuki Akita Jahangir
YA
Alam
Patricia J
PJ
Culligan
Veronica
V
Escamilla
John
J
Feighery
Andrew S
AS
Ferguson
Peter
P
Knappett
Brian J
BJ
Mailloux
Larry D
LD
McKay
Marc L
ML
Serre
P Kim
PK
Streatfield
Mohammad
M
Yunus
Michael
M
Emch
D001151:Arsenic / Q000302:isolation & purification*; D001459:Bangladesh / Q000453:epidemiology; D002648:Child; D003967:Diarrhea / Q000453:epidemiology*; D006801:Humans; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014881:Water Supply
D014874:Water Pollutants, Chemical; D001151:Arsenic