Sunlight reduces bacteria inside buildings

Sunlight reduces bacteria inside buildings

You likely don’t think about it much. And that’s good, because it can seem a little creepy and even gross. We’re talking about the untold amount of bacteria that exists in your home, workplace, schools and other buildings where we spend so much of our time.

Whole colonies of microorganisms live inside the buildings with which we are so familiar. These bacteria live in dust. Even if you clean regularly, or hire someone to do it, your rooms still are loaded with bacteria.

To learn more about these bacterial roommates of ours, researchers from the University of Oregon constructed teensy, dollhouse-sized rooms and put dust from people’s homes inside the rooms. Some rooms were designed not to let any light in. Some had regular windows to allow sunlight to stream in. Others had special coating on the windows to let in only ultraviolet, or U-V, light.

The scientists put the rooms outside for exposure to daylight. They controlled the temperature in each room, to keep it similar to that inside a home. After 90 days, they analyzed the bacteria in each room.

What they found was pretty interesting. There were about twice as many viable bacteria in the dark rooms as in the light ones. Viable bacteria are those that are able to reproduce.

The kind of light flowing into the room made little difference in bacterial population.

Additionally, the researchers noted the dark rooms had bacteria related to types known to cause respiratory illness. The rooms where light did penetrate had almost none of these types of bacteria.

So, to maintain a healthy indoor atmosphere, start this daily habit: Pull back those room-darkening curtains when you start your day, and let in the light.

Related Episodes