Can I get Covid-19 from second-hand smoke?

While further studies are needed to understand if second-hand smoke can lead to the spread of Covid-19, experts say it is theoretically possible.

Assistant professor at the division of pulmonary and critical medicine at the Johns Hopkins University School of Medicine in the US, Dr Panagis Galiatsatos, said second-hand smoke can propel viruses into the air from the nose and throat.

“Second-hand cigarette smoke is known to cause health problems, and though there isn’t yet scientific proof that it can spread the coronavirus, theoretically it’s a possibility.”

The school’s Dr Amesh Adalja said Covid-19 may spread “if someone is smoking a cigarette and coughing at the same time”.

A study by Andrea DeCastro Mendez, Milagro Escobar, Maria Romero and Janet M Wojcicki from the departments of paediatrics,  epidemiology and biostatistics at the University of California, said “second-hand smoke may facilitate transmission of Covid-19, as the virus attaches to particles expelled by smokers and can travel longer distances”.

“Viral particles can travel up to six times farther than if the virus was simply in the air in the absence of smoke. Furthermore, smokers tend to exhale more forcefully, and smokers infected with Covid-19 could have more particles pushed from their lungs to travel greater distances.”

The study also highlighted overcrowding in homes where there are smokers and people gathering together to smoke as likely environments for a rapid spread of the virus. 

The study, however, found an increased risk associated with exposure to second-hand smoke in one group they studied but not in another, and called for further research.

The US Food and Drug Administration (FDA) warned that smoking cigarettes increases the risk of more severe illness from Covid-19, which could result in hospitalisation and even death. 

“Smoking cigarettes can cause inflammation and cell damage throughout the body and can weaken your immune system, making it less able to fight off disease,” said the FDA.