Arsenic does not increase your CVD risk unless you smoke or have been a heavy smoker

http://www.sciencedirect.com/science/article/pii/S0041008X1530003X



This study is indeed very interesting egos the authors did statistics to separate the effect on arsenic and smoking on your CVD risk.
Arsenic measured in your toe nail is not it not correlated to your CVD risk.
If your are a smoker or if you stopped smoking after eight long-term use of tobacco then arsenic increases from 50 to 70 percent your risk of cardiovascular disease.
These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality.