Letting in sunlight can kill off harmful bacteria in your home

A new study from the University of Oregon has demonstrated the remarkable effect of sunlight as a disinfectant in the home. According to the researchers, sunlight can destroy around half of the bacteria living in household dust.

The experts want families and medical workers to become aware that sunshine could eliminate potentially harmful bugs linked to respiratory disease.

“Humans spend most of their time indoors, where exposure to dust particles that carry a variety of bacteria, including pathogens that can make us sick, is unavoidable,” said study lead author Dr. Ashkaan Fahimipour.

“Therefore, it is important to understand how features of the buildings we occupy influence dust ecosystems and how this could affect our health.”

For the investigation, the researchers created eleven identical rooms and filled them with dust obtained from residential homes. The team applied treatments to the windows, which were developed to transmit either visible, ultraviolet, or no light.

After 90 days, dust was collected from each environment and was tested for the composition, abundance, and viability of any bacteria present.

The study revealed that dust from dark rooms contained organisms related to species associated with respiratory diseases. These organisms were mostly absent in dust collected from rooms that were exposed to daylight.

In addition, dust from the sunlit rooms contained a smaller proportion of human skin-derived bacteria and a larger proportion of outdoor air-derived bacteria, which indicates that daylight can transform the microbiome of indoor dust to that of dust found outdoors.

“Our study supports a century-old folk wisdom, that daylight has the potential to kill microbes on dust particles, but we need more research to understand the underlying causes of shifts in the dust microbiome following light exposure,” said Dr. Fahimipour.

“We hope that with further understanding, we could design access to daylight in buildings such as schools, offices, hospitals and homes in ways that reduce the risk of dust-borne infections.”

Dr. Fahimipour pointed out that while more research is needed to apply the findings to the real world, there is no harm in letting more sunlight into our homes.

“There are a lot of procedures to prevent infections in hospitals already and in future we might also suggest sunlight as a cheap and easy measure to take.”

The study is published in the journal Microbiome.

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By Chrissy Sexton, Earth.com Staff Writer