[chris (OP)]

I'm putting together a piece to make viruses and the spread of infection more comprehensible for non-specialists. In explaining why the particles spread through the air and remain airborne for so long I would like to use an analogy like "these viruses are smaller than some of the particles of smoke that come off the end of a cigarette / exhaust pipe".

I thought I'd better fact check this first!

A flu virus is about 100nm (1/10,000th mm); but how big is an average smoke particle?

[chris (OP)]

No one helped me with this

[chiralSPO]

Smoke particles range from molecule size (polycyclic aromatic hydrocarbons, which can be as small as about 1 nm across; https://en.wikipedia.org/wiki/Pyrene) up to very large particles. Often people care about how much particulate mater below 2.5 µm across (PM_2.5) is in the air: https://airnow.gov/index.cfm?action=aqibasics.particle

This 2.5 µm limit puts them much larger than viruses (more like bacteria), but I don't know what the distribution of smoke particle sizes is.

[Colin2B]

Wood smoke 0.4 - 0.7 mm
Cigarette smoke, varies quite a bit but generally 0.2 - 0.8 m

Must have missed this one when it came up

[chiralSPO]

Wood smoke 0.4 - 0.7 mm
Cigarette smoke, varies quite a bit but generally 0.2 - 0.8 m

Those both sound big...   I've never heard of 0.2 m smoke particles before! Perhaps some typos involved??

[Colin2B]

Wood smoke 0.4 - 0.7 mm
Cigarette smoke, varies quite a bit but generally 0.2 - 0.8 m

Those both sound big...   I've never heard of 0.2 m smoke particles before! Perhaps some typos involved??

Whoops, forgot to edit in the μ when posting