Does inhaled pumice turn into concrete in the lungs?
I remember hearing the narrator of a film on the eruption of Tambora state that inhaled pumice/pumicite formed concrete in the lungs. I could not find any such statement online. Is this nonsense or it is a poor simplification?
I know that pumice is used as an aggregate in concrete. What we’ll need to find out is if it’s cementitious on its own. Note the distinction here – concrete has cement and aggregate in it.
Well, I found this article: CT patterns of pleuro-pulmonary damage caused by inhalation of pumice as a model of pneumoconiosis from non-fibrous amorphous silicates - PubMed
That says pumice inhalation causes something called Liparitosis. Which led me here: https://www.researchgate.net/publication/11391999_Unusual_pleural_involvement_after_exposure_to_amorphous_silicates_Liparitosis_Report_of_two_cases
There’s a lot of them there big words, but I think the answer to your specific question is no. It does mention " a massive nodular sclerosis," which sounds pretty bad.
Thanks Johnny_Bravo. I’m satisfied that pumice does not form concrete or harden in the lungs.
I am NOT an expert on this, but my understanding is:
Pumicite (powdered pumice) is a primary ingredient in cement, but it requires being mixed with lime to form cement. Lime by itself can also be used to create cement, by baking, slaking, and setting. Pumicite by itself, not so much.
Pumicite is basically powdered volcanic glass, so breathing it in can shred your throat and lungs, but unless you’re also breathing in powdered lime, you should be safe from cement-lung.
I don’t remember who I learned this from decades ago, but concrete is created when you mix sand and aggregate with cement. https://www.bobvila.com/articles/cement-vs-concrete/, so even if you were to inhale cement, it would never form concrete unless you also inhaled sand and rocks! 
Pet peeve #1868 is when those ancient astronaut theorists say the solid blocks of the pyramids and other ancient structures are concrete. They’re not as there would be evidence of the aggregate! 
I hate to ask, but even if a person or animal theoretically had all the right ingredients for forming concrete in the lungs could it ever happen?
The dry ingredients remain inert, but if they then swallowed water and jumped up and down a lot or, even better, rolled down a long, long hillside it would be a good start.
The chemical reaction that creates cement generates a lot of heat which might be fatal before the concrete even killed you.
Weeeeeeeeeeeeeeeee…clunk!
The lungs are pretty wet, I don’t think you’d need to inhale water separately. But i agree that the heat of the reaction might well cook you (and kill you) before the mixture finished turning into concrete.
Nobody here seems to know what concrete is or the difference between concrete and cement. The answer is no, inhaling enough pumice will destroy your lungs but will not produce any concrete.
Other than the multiple posters who mention it…
You’re right. I don’t why I’m in a pissy mood right now. I apologize to you and every one else who got this right.
Sounds like a slight misunderstanding of pozzolanic ash.
Inhaled ash during an eruption is not going to get a chance to form cement of any kind, what with all the burning of the flesh it will be doing instead…