Superfund Research Program
Health Effects of Arsenic Longitudinal Study
Project Leader: Habibul Ahsan (University of Chicago)
Co-Investigators: Ana Navas-Acien, Muhammad G. Kibriya (University of Chicago), Farzana Jasmine (University of Chicago)
Grant Number: P42ES010349
Funding Period: 2000-2021
Final Progress Reports
This prospective cohort study recruited 11,746 men and women (with 98% response rate) in Araihazar, Bangladesh, during 2000-2002 to investigate the health effects of arsenic exposure, with an initial focus on skin lesions and skin cancers, and also to establish a biorepository for future studies. In order to build a sampling frame, Dr. Ahsan’s team tested all 5,966 contiguous tube wells for arsenic within a well-defined area of approximately 26 square kilometers in collaboration with hydrology and geochemistry colleagues in the Coumbia University SBRP and enumerated all 65,876 people in the study area using these wells. Findings from this pre-cohort study survey are published in a series of papers [van Geen et al., 2002 and 2003; Parvez et al., 2005]. The biological samples have been processed and baseline questionnaire data have been processed and stored for all 11,746 cohort members. Dr. Ahsan’s team has completed the analysis of total urinary arsenic of all these individuals at baseline and also arsenic metabolites in a subset of 1,200 individuals (skin lesion cases and controls). Using baseline cross-sectional data on arsenic exposure and prevalent skin lesion cases the researchers conducted full dose-response analyses of the relationship between arsenic exposure and risk of skin lesions and factors modifying this dose-response effect. Dr. Ahsan’s team also collected full dietary data from all 11,746 cohort members using a modified meal-based dietary questionnaire and have validated this instrument [Chen et al., 2004].
Between October 2002 and May 2004, the team completed the first 2-yearly follow-up visits of the entire cohort. They were able to collect follow-up data on nearly 100% (11,686 of the total 11,746) of the baseline cohort. A total of 11,328 individuals completed the follow-up interview and clinical evaluations; 254 had migrated, 104 died and 60 could not be found. A total of 11,109 individuals (of 11,328 completed interview and clinical evaluations) provided urine samples. The follow-up data on all 11,746 individuals have been computerized. All 11,109 follow-up urine samples have also been analyzed for urinary total arsenic. In addition, they also analyzed blood arsenic levels for the newly identified skin lesion cases from this follow-up visit and their matched controls. Findings from this prospective investigation of the association between blood arsenic and skin lesion risk have been submitted for publication.
Second 2-yearly follow-up visits started in October, 2004; to date, the team has completed in-person follow-up home visits and collected questionnaire, clinical data and biological samples from 9,500 of our cohort members with similar response rates for different types of data as our first 2-yearly follow-up.
The findings and resources from this prospective cohort study have also yielded many other ancillary studies and publications including three additional R01 grants from NIH to investigate the genetic and nutritional aspects as well as chemoprevention of arsenic health effects.