Does Arsenic Exposure Increase the Risk of Development of Peripheral Vascular Diseases in Humans?

Arsenic has been well documented as a major risk factor in the development of blackfoot disease (BFD), a unique peripheral vascular disease (PVD) endemic to the southwestern coast of Taiwan, where residents imbibed artesian well water containing excessive amounts of arsenic for more than 50 yr. Long-term arsenic exposure was also reported to be associated with mortality attributed to PVD. A tap-water supply system was implemented in the early 1960s in the BFD endemic areas. Artesian well water was no longer used for drinking and cooking after the mid-1970s. The objective of this study was to examine whether mortality attributed to PVD decreased after the consumption of artesian well water containing high concentrations of arsenic ceased and, if so, when the reduction occurred. Standardized mortality ratios (SMRs) for PVD were calculated for the BFD endemic area for the years 1971-2003. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. Data showed that mortality due to PVD declined gradually for approximately 25 to 27 yr following cessation of consumption of this arsenic artesian well water. Based on the reversibility criterion, the association between arsenic exposure and PVD-attributed mortality is likely to be causal.