According to a recent study of 322 Chinese cities, long-term exposure to air pollution is linked to an increased risk of irregular heartbeat, or arrhythmia.
Researchers said that common arrhythmia conditions, such as atrial fibrillation and atrial flutter, which can lead to more serious heart disease, affect millions of people globally.
While air pollution is a modifiable risk factor for heart disease, the evidence linking it with arrhythmia has been inconsistent.
To evaluate the link, the researchers analysed hourly exposure to air pollution and sudden onset of arrhythmia symptoms using data from 2025 hospitals in 322 Chinese cities.
"We found that acute exposure to ambient air pollution was associated with increased risk of symptomatic arrhythmia," said Renjie Chen, from Fudan University, Shanghai, China.
"The risks occurred during the first several hours after exposure and could persist for 24 hours. The exposure–response relationships between six pollutants and four subtypes of arrhythmias were approximately linear without discernable thresholds of concentrations," Chen said.
In the study, 1,90,115 patients with acute onset of symptomatic arrhythmia, including atrial fibrillation, atrial flutter, premature beats and supraventricular tachycardia, were evaluated.
According to the researchers, exposure to ambient air pollution was most strongly linked to atrial flutter and supraventricular tachycardia, followed by atrial fibrillation and premature beats.
They found that nitrogen dioxide (NO2) had the strongest association with all four types of arrhythmias among six pollutants, and that the association grew stronger with increased exposure.
The authors stated that though the association between air pollution and acute onset of arrhythmia is biologically plausible, the exact mechanisms are not yet fully understood.
They also said that some evidence has indicated that air pollution induces oxidative stress and systemic inflammation, affecting multiple membrane channels and impairing autonomic nervous function, which alters cardiac electrophysiological activities.
The researchers noted that the association between air pollution and acute onset of arrhythmia was immediate and therefore, highlights the need to protect vulnerable individuals during episodes of heavy air pollution.
They added that their study contributes to the growing body of evidence indicating the adverse cardiovascular effects of air pollution and emphasises the importance of reducing exposure to air pollution and providing prompt protection to susceptible populations worldwide.
The Guardian reported that a previous study found that on days with high pollution levels in England, hundreds more people were admitted to hospitals for emergency treatment after experiencing cardiac arrests, strokes, and asthma attacks.
Also, according to the British Heart Foundation's estimates from 2020, over the next ten years, more than 160,000 people may die due to air pollution-related strokes and heart attacks. Furthermore, particulate air pollution has a broader impact beyond heart disease, as research indicates that it raises lung cancer rates by activating dormant mutations that stimulate tumour growth.
(With inputs from PTI)
