Sunlight may be the best disinfectant for homes and hospitals, scientists have discovered, as throwing the curtains wide kills half of the bacteria in dust.
A study of dust collected from the vacuum cleaners of ordinary households found that letting in natural light could eradicate potentially harmful bugs linked to respiratory disease.
Scientists at the University of Oregon left samples of dust in rooms for 90 days – the typical length of time it lingers in homes – which were either completely dark or had windows letting in sunlight.
When the dust was analysed, sunlight was found to have destroyed bacteria closely related to Saccharopolyspora rectivirgula, which causes coughing and shortness of breath in agricultural workers triggered by mouldy hay in a condition known as ‘farmer’s lung’.
Dr Ashkaan Fahimipour, who led the research at the University of Oregon, said: ‘Based on our findings, I don’t see any harm in letting a little more sunlight into our homes.
‘There are also a lot of procedures to prevent infections in hospitals already, and in future we might suggest sunlight as a cheap and easy measure to take.’