Millions of people worldwide are chronically exposed to arsenic through drinking water,
including 35-77 million people in Bangladesh. The association between arsenic exposure
and mortality rate has not been prospectively investigated by use of individual-level
data. We therefore prospectively assessed whether chronic and recent changes in arsenic
exposure are associated with all-cause and chronic-disease mortalities in a Bangladeshi
population.
In the prospective cohort Health Effects of Arsenic Longitudinal Study (HEALS), trained
physicians unaware of arsenic exposure interviewed in person and clinically assessed
11 746 population-based participants (aged 18-75 years) from Araihazar, Bangladesh.
Participants were recruited from October, 2000, to May, 2002, and followed-up biennially.
Data for mortality rates were available throughout February, 2009. We used Cox proportional
hazards model to estimate hazard ratios (HRs) of mortality, with adjustment for potential
confounders, at different doses of arsenic exposure.
407 deaths were ascertained between October, 2000, and February, 2009. Multivariate
adjusted HRs for all-cause mortality in a comparison of arsenic at concentrations
of 10.1-50.0 microg/L, 50.1-150.0 microg/L, and 150.1-864.0 microg/L with at least
10.0 microg/L in well water were 1.34 (95% CI 0.99-1.82), 1.09 (0.81-1.47), and 1.68
(1.26-2.23), respectively. Results were similar with daily arsenic dose and total
arsenic concentration in urine. Recent change in exposure, measurement of total arsenic
concentrations in urine repeated biennially, did not have much effect on the mortality
rate.
Chronic arsenic exposure through drinking water was associated with an increase in
the mortality rate. Follow-up data from this cohort will be used to assess the long-term
effects of arsenic exposure and how they might be affected by changes in exposure.
However, solutions and resources are urgently needed to mitigate the resulting health
effects of arsenic exposure.
US National Institutes of Health.
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