The "smell of rain" that reminds you of earth has a fascinating explanation — and it may soon find practical use in industry.
-
Rain, forests, and sometimes bodies of water all produce a scent reminiscent of soil.
The reason is a compound called geosmin, produced by certain bacteria and released when they die.
The human nose is extraordinarily sensitive to geosmin.
If you poured a teaspoon of geosmin into a lake the size of 200 Olympic swimming pools, you would still be able to smell it.
The specific receptors in the nose that detect it were previously unknown, but a recent study successfully identified them (OR11A1, if you really wanted to know).
-
Geosmin is not harmful, but it can negatively affect the taste and smell of water or food.
A further concern is that high concentrations of geosmin may indicate the presence of unwanted microorganisms — ones that produce various toxic compounds.
-
The researchers hope to use their successful identification of these receptors to mimic their mechanism of action in electronic sensors.
Such sensors could assist in monitoring water and food during production and storage processes, helping to ensure that products reach consumers at a high quality standard.