The emergence of the air pollutant ozone as a significant cardiovascular killer?

[Graphical Present] Formation and biological effects of ozone on the cardiovascular system. Ozone (O3) is formed by photochemical reactions (UV light from the sun) of oxygen in the atmosphere and is facilitated by nitrogen oxides (e.g. ·NO2) from traffic combustion exhaust and by high temperature. O3 can react with volatile organic compounds (VOCs) in the air and form highly toxic secondary organic aerosols (SOAs). In the lung and circulation, O3 will induce inflammation by release of interleukin-2 (IL-2) and tumour necrosis factor alpha (TNFα), trigger oxidative stress by direct oxidation of biomolecules but also by enhanced secondary formation of reactive oxygen species, and increase the levels of the vasoconstrictor endothelin-1 (ET-1). In addition, autonomic control is disturbed, resulting in a reduction in heart rate variability (HRV). All of these pathophysiological processes will promote hypertension, coronary ischaemia, and impairment of autonomic control. © 2023 The Author(s). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.