Does arsenic exposure increase the risk for diabetes mellitus?

OBJECTIVE Long-term arsenic exposure has been reported to associated with prevalence, incidence, and mortality of diabetes mellitus (DM). A tap water supply system was implemented in the early 1960s in the blackfoot disease (BFD) endemic areas. The objective of this study is to examine whether DM mortality decreased after the improvement of drinking water supply system through elimination of arsenic exposure from artesian well water. METHODS Standardized mortality ratios (SMRs) for DM were calculated for the BFD endemic area for the years 1971-2000. RESULTS The study results show that mortality from DM declined in females (but not in males) gradually after the improvement of drinking water supply system. CONCLUSIONS Based on the reversibility criterion, the association between arsenic exposure and DM is likely to be casual for females but not in males.