Recent epidemiologic studies show that increased levels of air pollutants are positively associated with cardiovascular
morbidity and mortality. Inhalation of air pollutants affects heart rate, heart rate variability, blood pressure,
vascular tone, blood coagulability, and the progression of atherosclerosis. Several categories within the
general population (i.e., people with pre-existing cardiovascular disease and diabetic and elderly individuals) are
considered to be more susceptible to air pollution–mediated cardiovascular effects. Major mechanisms of
inhalation-mediated cardiovascular toxicity include activation of pro-inflammatory pathways and generation of
reactive oxygen species. Although most studies focus on the influence of systemic effects, recent studies indicate
that ultrafine particles may be translocated into the circulation and directly transported to the vasculature
and heart where they can induce cardiac arrhythmias and decrease cardiac contractility and coronary
flow