[user_7832]

Fun fact, geosmin (one of the main compounds in the smell) can be smelt by humans at staggeringly low concentrations (part per trillion!)

For comparison, sharks detect blood in water in the parts per million range (which itself is already super impressive.)

https://en.wikipedia.org/wiki/Geosmin

https://www.acsh.org/news/2018/07/28/geosmin-why-we-smell-ai...