The association between arsenic exposure from drinking water and arterial embolism and thrombosis in Northeastern Taiwan: Preliminary results

Arsenic exposure is an important public health issue worldwide. However, the association of arsenic exposure with diverse health effects at low-to-moderate level remains to be elucidated. The aim of this study is to elucidate the dose-response relationship between ingested arsenic and vascular occlusions for low-to-moderate level. A total of 7,359 residents in northeastern arseniasis-endemic areas in Taiwan were followed from 1998 to 2009. The disease status of each subject was ascertained through linkage with computerized Taiwan National Health Insurance (NHI) database. Cox regression analysis was used to determine the hazard ratio of the disease associated with arsenic concentration in well water. There were 267 newly diagnosed arterial embolism and thrombosis cases during a follow-up period of 76,180 person-years. The crude incidence rate (per 10,000 person-years) was 249, 375, 320, 467, 449 and 496 respectively in arsenic level of ≤ 10.0, 10.1-25.0, 25.0-50.0, 50.1-100.0, 100.1-400.0 and > 400.0 μg/L. The hazard ratio was 1.55 (95% confidence interval (CI), 1.02-2.36), 1.34 (95% CI, 0.87-2.08), 1.76 (95% CI, 1.18-2.70), 1.77 (95% CI, 1.19-2.62) and 2.23 (95% CI, 1.37-3.64) in arsenic level from 10.1-25.0 to >400.0 when compared to arsenic level ≤ 10.0 μg/L after adjustment of age, sex, education level, cigarette smoking, hypertension, diabetes and hyperlipidemia. We concluded that there was a monotonous trend between arsenic concentration in well water and risk of arterial embolism and thrombosis. The significant increased disease risk can be observed in arsenic level as low as 10.1-25.0 μg/L.