31 Aug Good things emerging from the fog
By Rachel de Lastic, UNE Discovery Voyager
There is something special happening on those cold foggy mornings blanketing the landscape around us. Emerging research has found that fog is much more than just water vapor, it is biologically alive and full of bacteria that help clean our air.
Source: Dmitry Makeev, Creative Commons
A recent study led by Thi Thuong Thuong Cao at Arizona State University looked at radiation fog events over a two-year period in Pennsylvania. She was interested in the bacterial composition and activity of the fog aerobiome, which is a term used to describe the living component of our air full of microorganisms like bacteria, fungi, algae and viruses.
The study found that fog provides a habitat for thousands to millions of bacteria per cubic meter, comparable to the concentration of bacteria living in the ocean. The moisture in the air promoted a collection of bacteria and other microorganisms that was distinctly different to the aerobiome of dry air. Specifically, they found the fog was rich in a type of bacteria called Methylobacterium, one that is very helpful for cleaning up pollutants in our air.
The moisture in the fog helps to boost the populations of these bacteria, providing a suitable habitat for them to grow, multiply and eat. Picture one big bacteria dinner party taking place on a microscopic level in the fog. The main course – formaldehyde; a harmful air pollutant produced from combustion processes like burning wood or car exhaust fumes.
Incredibly, the study found that the bacteria consumed and degraded formaldehyde at an unprecedentedly high rate. And they didn’t just eat it. The researchers found that when formaldehyde levels got too high it became toxic for the bacteria, so they would work overtime to degrade it to comfortable levels.
This new research highlights how fog is in fact a living system that provides an important ecosystem service. The morning blanket of fog (and the bacteria contained in its droplets) is quietly cleaning up a harmful air pollutant, helping to bring in a breath of fresh air for the new day.