Physical Activity in Polluted Air—Net Benefit or Harm to Cardiovascular Health? A Comprehensive Review

Abstract

Both exposure to higher levels of polluted air and physical inactivity are crucial risk factors for the development and progression of major noncommunicable diseases and, in particular, of cardiovascular disease. In this context, the World Health Organization estimated 4.2 and 3.2 million global deaths per year in response to ambient air pollution and insufficient physical activity, respectively. While regular physical activity is well known to improve general health, it may also increase the uptake and deposit of air pollutants in the lungs/airways and circulation, due to increased breathing frequency and minute ventilation, thus increasing the risk of cardiovascular disease. Thus, determining the tradeoff between the health benefits of physical activity and the potential harmful effects of increased exposure to air pollution during physical activity has important public health consequences. In the present comprehensive review, we analyzed evidence from human and animal studies on the combined effects of physical activity and air pollution on cardiovascular and other health outcomes. We further report on pathophysiological mechanisms underlying air pollution exposure, as well as the protective effects of physical activity with a focus on oxidative stress and inflammation. Lastly, we provide mitigation strategies and practical recommendations for physical activity in areas with polluted air.

Co-exposure to urban particulate matter and aircraft noise adversely impacts the cerebro-pulmonary-cardiovascular axis in mice

“…Importantly, in chronic PM exposure models most cardiovascular complications were prevented in Nox2 knockout mice [ 60 ] and p47phox knockout mice [ 61 ]. These pathophysiological mechanisms are also shared in part by other air pollutants such as ozone, nitrogen dioxide and sulfur dioxide with significant health effects as previously reviewed [ 8 , 62 ].…”

Long-term exposure to ambient PM2·5, active commuting, and farming activity and cardiovascular disease risk in adults in China: a prospective cohort study

“…Engaging in physical activity improves antioxidant capacity, anti-inflammatory effects, and anti-atherosclerosis. 23 , 24 Additionally, physical activity improves cardiorespiratory fitness and is favourably associated with risk factors for cardiovascular disease, such as obesity, lipid profiles, and blood pressure. 24 However, increased physical activity and extended outdoor time can lead to increased inhalation of PM 2·5 .…”

“…Long-term exposure to PM 2·5 induces oxidative stress and inflammation, which can further trigger insulin resistance, endothelial dysfunction, and the progression of atherosclerosis. 23 Epidemiological studies have shown that long-term exposure to PM 2·5 is associated with an elevated risk of cardiovascular disease. 4 , 5 …”

Lifestyle and environmental factors may induce airway and systemic inflammation in firefighters

“…The World Health Organization (WHO) described that 9 of 10 people in the world breathe polluted air exceeding the WHO recommended values for ambient air quality (WHOb n.d. ; Hahad et al 2021 ). Consequently, air pollution (including fire smoke particles) is one of the major contributors to disease and increased morbimortality, especially cancer, cardiovascular disease and respiratory disease (Bachmann et al 2020 ; Hahad et al 2021 ). It was observed that wildfire particulate matter may impact respiratory health more than PM from other sources (Aguilera et al 2021 ).…”