Yep, your granny was right (aren’t they nearly always?). New research found that bacteria in dust lives happily in dark rooms. Bleurgh.

So keeping your windows clean and your curtains or blinds open could help prevent you catching the lurgy. 

A team of researchers at the University of Oregon created eleven identical climate-controlled miniature rooms and added dust collected from residential homes. They treated the windows so they had visible light, ultraviolet light, or no light. It turns out that in dark rooms about 12 per cent of bacteria were alive and able to reproduce, while only 6.8 per  cent of bacteria exposed to daylight could do the same. 

Dr Fahimipour, who led the research said: “Our study supports a century-old folk wisdom, that daylight has the potential to kill microbes on dust particles." It sounds like the old wives' tale was true - that bright, airy rooms are good for you (and teenage boys' bedrooms are petri dishes of grossness).

So there you go, letting the light in isn’t just good for your mood, it seems. And if you’ve caught the Mrs Hinch bug, there’s a new reason to keep your home clean and bright. 

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