Sunlight on the room can kill bacteria in the dust

a recent study published in the open-access journal Microbiome showed that allowing sunlight to shine through windows into a room can kill bacteria living in dust.
at the University of Oregon found that an average of 12 percent of bacteria in dark rooms survive and reproduce. By contrast, only 6.8 per cent of bacteria in sun-exposed rooms survived, while only 6.1 per cent of bacteria exposed to ultraviolet light were still fertile.
, study's co-author Ashkaan K. Fahimipour, said: "Humans spend most of their time indoors, which makes it inevitable that we will be exposed to dust that carries a variety of bacteria, even pathogenic bacteria. Therefore, it is important to understand how buildings affect the ecological environment of dust and how they affect human health.
researchers created 11 identical climate-controlled miniature rooms, simulated real-life buildings, and then put dust collected from the homes into them. They treated the windows of the room in three ways so that they could penetrate visible light, ultraviolet light, or inability to see through light. After 90 days, the researchers collected dust from each environment and analyzed its bacterial composition, content, and reproductive capacity (vibrantness).
dust in the dark carries a variety of microorganisms closely related to respiratory diseases, which are low in dust exposed to daylight. The researchers found that the proportion of bacteria from human skin sources in the sun was smaller than dust in the dark, and the proportion of bacteria from outdoor air sources was higher. This may indicate that daylight makes the microbial composition of indoor dust more similar to the bacterial community found outdoors.
Fahimipour said: "Our study supports a century-old folk wisdom that sunlight has the potential to kill microbes on dust particles, but we also need to do more research into the underlying pathogenesis of sunlight that changes the composition of microbes in dust." We hope that with further understanding, lighting solutions can be designed for buildings such as schools, hospitals and homes to reduce the risk of dust spreading bacteria and infection. However
, the researchers caution that the micro-indoor environments used in the study were exposed to only a relatively narrow range of light doses. Although the light dose chosen by the researchers is similar to the light dose in most buildings, there are still many architectural and geographic features that produce lower or higher light doses, so further research is needed. (Source: Lu Yi, China Science Daily)