Arsenic exposure from drinking water and mortality from cardiovascular disease in Bangladesh: prospective cohort studyBMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d2431 (Published 05 May 2011) Cite this as: BMJ 2011;342:d2431
- Yu Chen, associate professor of epidemiology1,
- Joseph H Graziano, professor of environmental health sciences2,
- Faruque Parvez, associate research scientist 2,
- Mengling Liu, associate professor of biostatistics1,
- Vesna Slavkovich, associate research scientist 2,
- Tara Kalra, project coordinator/data analyst3,
- Maria Argos, project coordinator/data analyst3,
- Tariqul Islam, project director 4,
- Alauddin Ahmed, field coordinator 4,
- Muhammad Rakibuz-Zaman, study physician/laboratory manager 4,
- Rabiul Hasan, assistant field coordinator 4,
- Golam Sarwar, informatics manager 4,
- Diane Levy, senior staff associate 2,
- Alexander van Geen, Lamont research professor in Lamont-Doherty Earth Observatory 5,
- Habibul Ahsan, professor of epidemiology3
- 1Department of Environmental Medicine, New York University School of Medicine, New York, NY 10016, USA
- 2Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York
- 3Departments of Health Studies, Medicine and Human Genetics and Comprehensive Cancer Center, University of Chicago, Chicago, IL 60637
- 4University of Chicago and Columbia University Research Project Office, Dhaka, Bangladesh
- 5Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York
- Correspondence to: Y Chen , H Ahsan
- Accepted 28 February 2011
Objective To evaluate the association between arsenic exposure and mortality from cardiovascular disease and to assess whether cigarette smoking influences the association.
Design Prospective cohort study with arsenic exposure measured in drinking water from wells and urine.
Setting General population in Araihazar, Bangladesh.
Participants 11 746 men and women who provided urine samples in 2000 and were followed up for an average of 6.6 years.
Main outcome measure Death from cardiovascular disease.
Results 198 people died from diseases of circulatory system, accounting for 43% of total mortality in the population. The mortality rate for cardiovascular disease was 214.3 per 100 000 person years in people drinking water containing <12.0 µg/L arsenic, compared with 271.1 per 100 000 person years in people drinking water with ≥12.0 µg/L arsenic. There was a dose-response relation between exposure to arsenic in well water assessed at baseline and mortality from ischaemic heart disease and other heart disease; the hazard ratios in increasing quarters of arsenic concentration in well water (0.1-12.0, 12.1-62.0, 62.1-148.0, and 148.1-864.0 µg/L) were 1.00 (reference), 1.22 (0.65 to 2.32), 1.35 (0.71 to 2.57), and 1.92 (1.07 to 3.43) (P=0.0019 for trend), respectively, after adjustment for potential confounders including age, sex, smoking status, educational attainment, body mass index (BMI), and changes in urinary arsenic concentration since baseline. Similar associations were observed when baseline total urinary arsenic was used as the exposure variable and for mortality from ischaemic heart disease specifically. The data indicate a significant synergistic interaction between arsenic exposure and cigarette smoking in mortality from ischaemic heart disease and other heart disease. In particular, the hazard ratio for the joint effect of a moderate level of arsenic exposure (middle third of well arsenic concentration 25.3-114.0 µg/L, mean 63.5 µg/L) and cigarette smoking on mortality from heart disease was greater than the sum of the hazard ratios associated with their individual effect (relative excess risk for interaction 1.56, 0.05 to 3.14; P=0.010).
Conclusions Exposure to arsenic in drinking water is adversely associated with mortality from heart disease, especially among smokers.
Contributors: YC and HA designed the study. HA, YC, and JHG obtained funding. MA, TK, DL, and GS maintained and supervised the HEALS cohort database. FP, TI, AA, MR-Z, and RH supervised the fieldwork. VS and JHG supervised measurement of urinary arsenic. LvG supervised the measurement of water arsenic. YC and ML analysed the data. YC, HA, JG, and FP helped to interpret the results. YC, HA, and JG wrote the paper. HA is guarantor.
Funding: This study was supported by US National Institute of Health funding. The National Institute of Environmental Health Sciences and the National Cancer Institute provide support under the following grants: P42ES010349, R01ES017541, R01CA102484, R01CA107431, R01ES017541, R01ESO11601, P30ES09089, CA016087, ES000260, and CA014599. The views expressed in this paper are those of the authors and not necessarily those of any funding body or others whose support is acknowledged. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interest: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: The study procedures were approved by the ethics committee of the Bangladesh Medical Research Council and the institutional review boards of Columbia University and the University of Chicago. Verbal consent was obtained from study participants.
Data sharing: No additional data available.
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