Exposure to air pollutants like lead (Pb++) and carbon monoxide (CO), promotes the occurrence of cardiovascular diseases. Experimental studies have shown that Pb++ and CO block the L-type calcium channels, decreasing the calcium current (ICaL) and the action potential duration (APD), favoring the initiation of atrial arrhythmias. Our goal is to study the effects of Pb++ and CO at different concentrations, on ICaL and action potential using computational simulation. For this, we developed mathematical models of the air pollutants effects on the atrial L-type calcium channel and they were incorporated in a mathematical model of human atrial cell and in a 2D model of atrial tissue. Our results suggest that the Pb++ and CO block the ICaL current in a fraction that increases as the concentration increases, generating an APD shortening. The combined effect of both air pollutants generated an APD shortening and a stable rotor, which is considered as a pro-arrhythmic effect. These results are consistent with experimental studies. In silico studies may contribute to a better understanding of the mechanisms by which air pollutants have unhealthy effects on cardiac system. © 2017 IEEE Computer Society. All rights reserved.