Geosmin is associated with which distinctive earthy smell?

Geosmin is associated with which distinctive earthy smell?

• A. Ammonia
• B. Chlorine
• C. Geosmin
• D. Ozone

Answer: (C)

Geosmin is the compound responsible for that distinctive earthy smell you notice after rain. It’s produced by soil-dwelling microbes, especially actinobacteria, and when the soil is wetted, geosmin becomes volatile and wafts into the air. Humans can detect it at incredibly low concentrations, which is why the earthy scent is so noticeable even though only tiny amounts are present. The other substances produce different odors: ammonia has a sharp, pungent smell; chlorine smells like bleach; ozone gives a sharp, electric-off-putting scent often associated with thunderstorms. So the earthy smell tied to rain and soil is geosmin.

Geosmin is the compound responsible for that distinctive earthy smell you notice after rain. It’s produced by soil-dwelling microbes, especially actinobacteria, and when the soil is wetted, geosmin becomes volatile and wafts into the air. Humans can detect it at incredibly low concentrations, which is why the earthy scent is so noticeable even though only tiny amounts are present. The other substances produce different odors: ammonia has a sharp, pungent smell; chlorine smells like bleach; ozone gives a sharp, electric-off-putting scent often associated with thunderstorms. So the earthy smell tied to rain and soil is geosmin.