Does arsenic exposure increase the risk for coronary heart disease?

Chun-Yuh Yang, Ph.D., M.P.H.
Professor, Director and Dean
Institute of Public Health
College of Health Sciences
Kaohsiung Medical University
TAIWAN

Arsenic has been well documented as the major risk factor for blackfoot disease (BFD), a unique peripheral vascular disease that was endemic in the southwestern coast of Taiwan , where residents had used high-arsenic artesian well water for more than 50 years. Long-term arsenic exposure has also been reported to associated with ischemic heart disease (CHD) mortality in a dose-response relationship. 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 is to examine whether CHD mortality decreased after consumption of high-arsenic-containing artesian well water ceased and, if so, when the reduction occurred. Standardized mortality ratios (SMRs) for CHD were calculated for the BFD endemic area for the years 1971-2000. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. The study results show that mortality from CHD declined gradually after the improvement of drinking water supply system to eliminate arsenic exposure from artesian well water. Data also show that mortality attributed to CHD declined gradually for approximately 17 to 20 years following cessation of consumption of high-arsenic artesian well water. Based on the reversibility criterion, the association between arsenic exposure and CHD mortality is likely to be causal.