Important air pollutants

Air pollution has an important impact on the cardiovascular system. Some time back I had reviewed a study report which mentioned that fine particulate air pollution increases ventricular arrhythmias in adolescents [1]. Fine particles with aerodynamic diameters ≤2.5 μm (PM_2.5) exposure has been associated with a risk of mortality and cardiac arrhythmias in adults [2]. Primary pollutants are those directly released into the air from sources of pollution. Secondary pollutants are formed through chemical transformation through interactions with other constituents or atmospheric conditions like sunlight and water vapour. Primary pollutants include nitric oxide, nitrogen dioxide, carbon monoxide, sulphur dioxide, carbon dioxide and PM_2.5.

PM_2.5 contain organic carbon species, elemental carbon and trace metals. Ozone is the most prevalent secondary oxidant. A number of inorganic and organic acids, volatile organic compounds (VOC) and semivolatile organic compounds (SVOC) are also formed as secondary pollutants. Benzene, toluene, xylene, 1,3-butadiene and polycyclic aromatic hydrocarbons are some of the important organic compounds. Inorganic compounds include nitrates, ammonium and sulphates. These are part of the particulate matter (PM). PM₁₀ are also called thoracic particles as they penetrate deep into the lungs. Maximum health risk is for the fine particles PM_2.5. Coarse particles are PM_2.5-10. There are also ultrafine particles less than 0.1 μm.

References

1. He F, Yanosky JD, Fernandez-Mendoza J, Chinchilli VM, Al-Shaar L, Vgontzas AN, Bixler EO, Liao D. Acute Impact of Fine Particulate Air Pollution on Cardiac Arrhythmias in a Population-Based Sample of Adolescents: The Penn State Child Cohort. J Am Heart Assoc. 2022 Sep 14:e026370. doi: 10.1161/JAHA.122.026370. Epub ahead of print. PMID: 36102241.
2. Ueda K, Nitta H, Ono M. Effects of fine particulate matter on daily mortality for specific heart diseases in Japan. Circ J. 2009 Jul;73(7):1248-54. doi: 10.1253/circj.cj-08-1149. Epub 2009 May 8. Erratum in: Circ J. 2009 oCT;73(10):1972. PMID: 19423947.