Running in Polluted Air Is a Two-edged Sword

Physical Exercise in Low Air Pollution Areas Is Cardioprotective But Detrimental for the Heart in High Air Pollution Areas

Thomas Münzel; Omar Hahad; Andreas Daiber


Eur Heart J. 2021;42(25):2498-2500. 

In This Article

Mitigation Strategies for Air Pollution

Current approaches to mitigate air pollution and their impact have been previously reviewed and can be broadly classified into: (i) active personal exposure mitigation with home air cleaning and personal equipment (e.g. face masks); (ii) modification of human behaviour to reduce passive exposures; and (iii) pharmacological approaches.[7,8] The N95 respirator studied under ambient PM2.5 exposure conditions at both high and low levels of exposure over a few hours has been shown to reduce systolic blood pressure and improve heart rate variability.[7,9] Closing car windows, air-conditioning, and cabin air filters represent approaches that could be important in those who are susceptible, but only in those spending large amounts of time in transportation microenvironments. Behavioural strategies such as air pollution avoidance by changing travel routes, staying indoors/closing windows, and limiting outdoor recreation/exercise can help limit air pollution exposure (reviewed in Munzel et al.[8]), but may bring other risks such as higher exposure to indoor pollutants or adverse health effects due to a sedentary lifestyle. Health impact modelling and epidemiological studies have demonstrated that the benefits of aerobic exercise nearly always exceed the risk of air pollution exposure across a range of concentrations, and for long durations of exercise for normal individuals (>75 min). Therefore, guiding healthy people to avoid outdoor activity in areas with high PM2.5 pollution has the potential to produce greater harm than benefit, given the low absolute risk for cardiovascular or respiratory events.