By: Erin Stair, MD, MPH

Can the new coronavirus spread via smoke, specifically cigarette smoke?

Since  the coronavirus (COVID-19) is a new virus, the manner and ways in which it spreads are still being discovered. Viruses aren’t alive. But they are uncanny in their ability to spread, mutate and avoid being detected and destroyed by our immune system.

Recently I was wondering if the coronavirus could spread via smoke, because I noticed people smoking on the streets of New York City, where I live. This is even after the social distancing mandate and lock-down order. I’ve even seen some people with their face mask slipped to one side of their mouth and a cigarette hanging out the other. ( Hi, Ben Affleck!) I also live in an apartment building and sometimes folks stand outside the building and smoke. Sometimes it’s cigarettes, sometimes it’s marijuana. Either way, the smoke travels upward and can enter apartments through open windows, etc.  It’s also difficult to escape cigarette smoke…, something that becomes more poignant in the throes of an airborne pandemic.

Another reason I was interested in whether the coronavirus could spread via smoke is because of a historical Smallpox outbreak that baffled folks. It happened in a hospital in Germany in 1968. The hospital successfully implemented the public health measures of isolation and quarantine, but despite that, folks became infected with Smallpox. No one knew how it was happening, but eventually they figured it out by doing a smoke test. What happened was that cigarette smoke from a room on one of the lower floors, traveled out a window that was cracked open. The smoke had help from an updraft coming from a radiator that was below the window. The smoke travelled upward and entered through rooms with open windows on higher floors. People came in contact with the smoke and got infected. Wild, right? And really scary too.

I was also curious if the virus could survive and spread via air ventilation systems. Again, I live in an apartment building and our ventilation systems are all connected. Does that mean if a neighbor is sick and isolated in an adjacent apartment, that I could potentially become infected with the coronavirus via our ventilation system?

There are a lot of unknowns with this virus, but to learn more about whether the coronavirus could spread via smoke and other means, I reached out to Dr. Glen Reeves. I subscribe to his incredibly informative, thorough and eclectic newsletter, “Medical Weapons of Mass Destruction” in which he elaborates on trending public health issues. Recently he did a great newsletter on the coronavirus. For the record, he doesn’t view the coronavirus as a biological weapon that was made in a lab in China.  I know that theory is floating around, so I want to address it head on. Despite the title of his newsletter, he dives into a lot of different topics around emerging infectious diseases, some of which I’m sure can be used for bioterrorism, but that wasn’t the case with COVID-19. Lucky for me, he responded with some great answers for how the Coronavirus is spread. I’m posting these answers below. If you don’t feel like reading, I also discussed and read them aloud in my Instagram TV video here. If you don’t like Instagram, I uploaded it to my YouTube channel here.

( And for the record, I am using Coronavirus and COVID-19 interchangeably throughout this piece.)

So, first things first: Can the Coronavirus Spread Via Smoke?

Dr. Reeves wrote that the coronavirus needs to be heated to at least 60 degrees Centigrade for several minutes to be killed. The flame tip is much hotter than 60 degrees Centigrade, however, when smoke is exhaled, it doesn’t get exposed to the flame. Therefore, if the smoker is shedding virus, most of it won’t be killed.

Can it spread via ventilation and air systems?

Dr. Reeves wrote that that there is nothing in the ventilation or air systems in apartment buildings that would kill the coronavirus. Filters won’t stop it either.

Do the above answers mean that we can catch COVID-19 via a smoker’s inhaled smoke or a ventilation system? I’d say it’s possible, and I would be very cautious, especially around cigarette smoke. If you live in a building with smokers, perhaps you can request the building superintendent to ban it. ( I mean, on a normal non-pandemic day, it’s not good to inhale.)  If you come across smokers outside, avoid getting in their path.

What about other surfaces, food and water?

Dr. Reeves wrote that the coronavirus doesn’t seem to spread through exposure to food. He said it was wise to was the surfaces of fruits and vegetables. The coronavirus hasn’t been found in drinking water. The survival time on metal, glass and ceramics can be up to 5 days. Wooden objects? 4 days. Cardboard and Newspapers? 24 hours. Interestingly enough, the coronavirus does not seem to survive well on Copper ( only 4 hours) and Aluminum ( 2-8 hours).  It survives up to 2-3 days on Stainless Steel and also up to 2-3 days on Plastics and Subway Seats.

( I also asked him about dog fur, but he wasn’t sure about that. Recently, the CDC recommended that we social distance our dogs and cats from humans, as some have tested positive for the Coronavirus. My personal belief is that the dogs and cats are MORE at risk of catching it from us, then us catching it from them.)

Then I asked how long the virus survives on unwashed hands. Meaning, if I touch one of the objects above, how long will any transmitted virus survive on my hands?

Dr. Reeves said he searched several references for this question, but did not receive a definitive answer from any. Palmar sweating would help remove the Coronavirus, since the virus is lipid soluble ( meaning it dissolves in fat). His guess was that it was no more than a few hours. ( I read that it was closer to 5 minutes, though also with no definitive sources, so I think it’s safe to assume somewhere between 5 minutes and a few hours.)

I hope this information is useful. I’m convinced the Coronavirus can spread via smoke, so if you get anything out of this blog, avoid smoking if you can ( I know it’s addicting) and avoid crossing paths with smokers. If you have any questions, I’d say leave a comment here, but I often don’t get a chance to respond to them. The best thing to do is track me down in my Facebook Group- Blooming Wellness Peer Support with Erin Stair MD, MPH. There’s a good, intellectual crowd in the group and we discuss a lot of issues, such as this one.

Other Coronavirus-related blogs to read:

We need to Ban Live Meat Markets now.