The 95% CIs are pretty wide. But an interesting study indeed.
Zhang C, Mao G, He S, Yang Z, Yang W, Zhang X, Qiu W, Ta N, Cao L, Yang H, Guo X. Relationship between long-term exposure to low-level arsenic in drinking water and the prevalence of abnormal blood pressure. Journal Of Hazardous Materials, 2013 Nov 15; Vol. 262, pp. 1154-8.
Arsenic increases the risk and incidence of cardiovascular disease. To explore the impact of long-term exposure to low-level arsenic in drinking water on blood pressure including pulse pressure (PP) and mean arterial blood pressure (MAP), a cross-sectional study was conducted in 2010 in which the blood pressure of 405 villagers was measured, who had been drinking water with an inorganic arsenic content 30-50 years of arsenic exposure and a 2.95-fold (95%CI: 1.31-6.67) increase in the group with >50 years exposure. Furthermore, the odds ratio for prevalence of abnormal PP and MAP were 1.06 (95%CI: 0.24-4.66) and 0.87 (95%CI: 0.36-2.14) in the group with >30-50 years of exposure, and were 2.46 (95%CI: 0.87-6.97) and 3.75 (95%CI: 1.61-8.71) for the group with >50 years exposure, compared to the group with arsenic exposure ≤ 30 years respectively. Significant trends for Hypertension (<0.0001), PP (<0.0001) and MAP (p=0.0016) were found. The prevalence of hypertension and abnormal PP as well as MAP is marked among a low-level arsenic exposure population, and significantly increases with the duration of arsenic exposure.