Cross-sectional: 382 men and 516 women of age over 30 and residing in arseniasis hyperendemic villages of Taiwan Exposed: 779 (drunk artesian well for some time) Unexposed: 119 (never used artesian well)
Taiwan
Long-term arsenic exposure calculated, structured questionnaire, and measured arsenic concentration in well water Cumulative arsenic exposure index was used
WHO protocol: Systolic blood pressure ≥160 mm Hg, Diastolic blood pressure ≥95 mm Hg AND/OR history of hypertension regularly treated with antihypertensive drugs
Age, sex, body mass index, fasting serum triglyceride levels, diabetes mellitus, proteinuria
0 years 1–10 years 11–20 years 21–30 years >30 years 0 μg/L 10–700 μg/L 710–900 μg/L >900 μg/L Unknown 0 μg/L-years 100–6300 μg/L years 6400–10800 μg/L-years 10900–14700 μg/L-years 14800–18500 μg/L-years >18500 μg/L-years Unknown
Cross-sectional: 1595 residents 30 years or older Exposed: 1481 (had a history of arsenic-contaminated drinking water) Unexposed: 114 (had no history of arsenic-contaminated drinking water)
Bangladesh
Arsenic concentration measured in artesian well water and consumption was assessed by structured questionnaire to estimate time-weighted mean arsenic levels (mg/L) for each subject
Systolic blood pressure ≥140 mm Hg, AND diastolic blood pressure ≥90 mm Hg
Cross-sectional: 1185 residents from Wisconsin, USA, who are 35 years or older and were drinking from private well water supply for 20 or more years Exposed: 40 (>2 μg/L) Unexposed: 34 (<2 μg/L)
Wisconsin, USA
Questionnaire survey for life-time history, usual drinking water consumption, use of water-treatment systems and family health history. Length of exposure estimated between July 2000 and January 2002
Prospective cohort: 18940 residents 40 years or older followed up for an average of 12 years Exposed: 2264 (residents from arsenic-exposed areas and drinking from tube wells) Unexposed: 16676 (residents from unexposed areas and drinking from tap water)
Taiwan
In one area, median arsenic concentration of the shared artesian well was used as exposure, whereas, in other area, the exposure was the arsenic level in the participants’ own tube wells. People using tap water or drinking water with <10 μg/L of arsenic were considered unexposed.
Systolic blood pressure ≥160 mm Hg, diastolic blood pressure ≥95 mm Hg, OR history of hypertension regularly treated with antihypertensive agents
Cross-sectional: 488 women and 383 men southwestern coast of Taiwan whose age is 30 years or older
Taiwan
Percentage of inorganic arsenic in urine was used to determine exposure
WHO protocol: Systolic blood pressure ≥140 mm Hg, Diastolic blood pressure ≥90 mm Hg, AND/OR history of hypertension regularly treated with antihypertensive drugs
Age, gender, body mass index, cigarette smoke, alcohol consumption, triglyceride level, cumulative arsenic exposure
Cross-sectional: 10,910 participants from Bangladesh who are married, 18 years or older, and have had resided in the area for at least 5 years
Bangladesh
Arsenic concentration was measured in the wells to estimate time-weighted well arsenic concentration (TWA) combining the water use behaviour for, an average, last 10 years for men and 8.3 years for women
Overall population: Systolic hypertension ≥140 mm Hg Diastolic blood pressure ≥90 mm Hg Systolic hypertension ≥140 mm Hg AND/OR Diastolic blood pressure ≥90 mm Hg Pulse blood pressure ≥55 mm Hg
Age, gender, body mass index, cigarette smoking status, education length, daily water consumption
