Environmental exposure to combustion-derived air pollution is associated with reduced functional capacity in apparently healthy individuals.

Prior toxicological exposure reports demonstrated the decremental effect of several air pollutants on the metabolic equivalents achieved during exercise testing (METs). There are no prior large scale epidemiological reports about the effect of environmental air pollution exposure on those parameters. We analyzed a cohort of apparently healthy individuals attending a screening survey program held between 2003 and 2009. Participants were included if residing within an 11 km radius from the nearest air pollution monitoring station. Linear regression models were fitted for the metabolic equivalents and adjusted to short- and long-term air pollutant exposure (particulate matter under 10 micron, sulfur dioxide, nitrogen dioxide, carbon monoxide and ozone). The models were adjusted for possible confounders that affect air pollution and stress testing measurements. The study population comprised 6,612 individuals (4,201 males and 2,411 females). We found a statistically significant short- and long-term negative correlation between air pollutants, mainly CO and NO2 and between the metabolic equivalents achieved. A similar short-term effect was found for SO2. We conclude that exposure to combustion-derived air pollutants has a short- and long-term decremental effect on cardiorespiratory fitness as measured by exercise stress testing. Our epidemiological data support previous toxicological reports.