Cannabis smoke and vaping combustion could damage the lungs and suppress the immune system, causing more severe coronavirus symptoms.

No public data links smoking or vaping with the coronavirus in the United States, but researchers believe those behaviors played a role in the outbreaks seen in Italy and China. A study of more than 40,000 coronavirus cases in China reported men were more likely to become infected than women. Men suffered a 2.8% fatality rate in the China study while women were at 1.7%.

One hypothesis supported by Michael Ryan, executive director of the World Health Organization’s Health Emergencies Program, theorizes that the difference in fatalities is tied to smoking. A 2010 national survey found that 62% of men had been smokers in their lifetime and only 3% of women. A New Jersey Journal of Medicine study stated that severe COVID-19 infections were more than twice as likely in Chinese coronavirus patients who smoked versus those that didn’t.RELATED: NORML Gives Marijuana Consumption Safety Guidelines During Coronavirus Outbreak

“From China and Italy, we see people who developed COVID-19 and had underlying lung disease, [they] have more complications and die more often,” Dr. Barry J. Make, a pulmonologist at National Jewish Health, told Insider. “So this is the perfect time to stop smoking.”

Studies show tobacco smoking compromises the immune system and causes lung inflammation. According to the American Lung Association, marijuana smoke injures cell linings in the lung, leading to wheezing and phlegm problems commonly reported by heavy users. The ALA adds that frequent cannabis-only smokers experience more respiratory-related healthcare visits versus nonsmokers.