Air Pollution Compromises Arterial Health

Some scientists hypothesize that exposure to air pollutants - particularly fine particulate matter – may compromise the endothelial cells of the cardiovascular system.   Ranjini M. Krishnan, from the University of Washington (Washington, USA), and colleagues analyzed data on 3,040 subjects, mean age 61 years, enrolled in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA), covering metropolitan areas of Chicago, Los Angeles, New York, St. Paul, and Winston-Salem, N.C.  Finding that an interquartile increase of only 3 micrograms/cubic meter in exposure to particulate matter less than 2.5 micrograms in diameter was associated with a decrease of 0.3% in flow-mediated dilation of the brachial artery, the team commented that the magnitude of that percentage increase of flow-mediated dilation equated to the effect of 5 years' increase in age, or of active tobacco smoking.  This effect was particularly pronounced among   younger individuals, women, nonsmokers, and those with mild hypertension (high blood pressure).  Observing that: “Long-term [fine particulate matter]exposure was significantly associated with decreased endothelial function according to brachial ultrasound results,” the study authors submit that: “These findings may elucidate an important pathway linking air pollution and cardiovascular mortality.”