Air pollution is a heterogenic mixture of gases, liquids and particulate matter (PM) present in the urban modern world. PM rates vary in size from a few nanometers to 10 micra diameter. The exposure to PM is associated to a major risk of cardiovascular diseases as explained by three mechanisms: induction of systemic inflammation and/or oxidative stress, alteration in the cardiac autonomic balance and direct action on the circulatory system, causing acute vasoconstriction, endothelial dysfunction and prothrombotic state. There is evidence suggesting that air pollution is associated with shortened prothrombine time, decrease in tissue plasminogen activator, increase of fibrinogen, factor VIII and factor von Willebrand, and platelet hyperactivity.