Health Effects of Arsenic Longitudinal Study (HEALS): Description of a multidisciplinary epidemiologic investigation

Abstract

Health Effects of Arsenic Longitudinal Study (HEALS), a multidisciplinary and large prospective cohort study in Araihazar, Bangladesh, was established to evaluate the effects of full-dose range arsenic (As) exposure on various health outcomes, including premalignant and malignant skin tumors, total mortality, pregnancy outcomes, and children's cognitive development. In this paper, we provide descriptions of the study methods including study design, study population, data collection, response rates, and exposure and outcome assessments. We also present characteristics of the study participants including the distribution of exposure and the prevalence of skin lesion at baseline recruitment. A total of 11,746 married men and women between 18 and 75 years of age participated in the study at baseline (a response rate of 98%) and completed a full questionnaire interview that included a food frequency questionnaire, with a response rate of 98%. Among the 98% of the participants who completed the clinical evaluation, over 90% provided blood samples and spot urine samples. Higher educational status, male gender, and presence of premalignant skin lesions were associated with an increased likelihood of providing blood and urine samples. Older participants were less likely to donate a blood sample. About one-third of the participants consumed water from a well with As concentration in each of three groups: >100 microg/l, 25-100 microg/l, and <25 microg/l. Average urinary As concentrations were 140 and 136 microg/l for males and females, respectively. HEALS has several unique features, including a prospective study design, comprehensive assessments of both past and future changes in As exposure at the individual level, a large repository of biological samples, and a full dose range of As exposures in the study population. HEALS is a valuable resource for examining novel research questions on the health effects of As exposure.

A cluster-based randomized controlled trial promoting community participation in arsenic mitigation efforts in Bangladesh

“…The two groups of villages were geographically separated. Using census data from the Bangladesh Bureau of Statistics, villages were matched on literacy rate and land ownership as these are strong indicators of socioeconomic status [23]. We also attempted to match villages on the proportion of As contaminated wells based on our household drinking water survey.…”

Arsenic Metabolism, Genetic Susceptibility, and Risk of Premalignant Skin Lesions in Bangladesh

“…The current case-control study was conducted within the Health Effects of Arsenic Longitudinal Study, a large prospective cohort study of 11,746 men and women established in year 2000 in Araihazar, Bangladesh. Details of the study and methods for Health Effects of Arsenic Longitudinal Study have been described elsewhere (22,23 Trained interviewers and physicians visited potential study participants in their homes to do in-person interviews, including a full dietary instrument (24). In addition, participants were clinically assessed for skin lesions across the entire body (22).…”

“…Details of the study and methods for Health Effects of Arsenic Longitudinal Study have been described elsewhere (22,23 Trained interviewers and physicians visited potential study participants in their homes to do in-person interviews, including a full dietary instrument (24). In addition, participants were clinically assessed for skin lesions across the entire body (22). We instituted a structured protocol, similar to the quantitative assessment of the extent of body surface involvement in burn patients (25), to quantify the size, shape, and extent of skin lesion involvement.…”

Gene Expression Profiles in Peripheral Lymphocytes by Arsenic Exposure and Skin Lesion Status in a Bangladeshi Population

“…Forty individuals were selected from the Health Effects of Arsenic Longitudinal Study (HEALS) cohort for examination of gene expression profiles (40). The HEALS is an ongoing, population-based study examining both short-term and long-term health effects of arsenic exposure from drinking water in Bangladesh.…”