Sunlight is the best disinfectant: Bacteria found in household dust is KILLED when rays of sunshine are allowed through an open window

Sunlight can kill harmful bugs and half the bacteria trapped in a room's dust
It destroys a bacteria that is heavily responsible for respiratory conditions
Researchers say the discovery could help hospitals remove a source of infection

Published: 20:00 EDT, 17 October 2018 | Updated: 20:09 EDT, 17 October 2018

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Sunlight really may be the best disinfectant, as letting light into a house kills off the bacteria in household dust.

Letting natural light into a room destroys around half of living bacteria in dust, a study has found.

Sunshine could eradicate potentially harmful bugs linked to respiratory disease, and researchers say hospitals as well as families should take note.

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Letting natural light into a room destroys around half of living bacteria in dust as well as Saccharopolyspora rectivirgula which is heavily involved in respiratory diseases (stock)

Scientists at the University of Oregon collected dust from household vacuum cleaners and left it in miniature rooms for 90 days.

The rooms were kept in darkness or had windows letting in sunlight and ultraviolet light.

When the dust was analysed, sunlight was found to have destroyed bacteria closely related to Saccharopolyspora rectivirgula.

More research is needed on whether this is harmful in household dust but Saccharopolyspora rectivirgula can trigger 'farmer's lung' in agricultural workers, causing coughing and shortness of breath from the dust in mouldy hay.

Dr Ashkaan Fahimipour, who led the research from the University of Oregon's Biology and the Built Environment Centre, said: 'We need a lot more research before we can apply this to real life but, based on our findings, I don't see any harm in letting a little 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.'

For their experiment, the US researchers created 11 climate-controlled rooms approximately one thirtieth the size of a household living room, at 14 feet (4.3 metres) wide.

Household dust, collected from the vacuum cleaners of ordinary homes, was placed in petri dishes within the rooms.

That dust was exposed to sunlight through a window, UV light filtered from outside or to complete darkness from an aluminium plate placed over the window.

Three months later dust samples from dark rooms had 12 per cent of bacteria alive and able to reproduce, compared to only 6.8 per cent of dust bacteria exposed to daylight and 6.1 per cent exposed to UV light.

Dust left in the dark contained more bacteria from human skin and less from outside. Researchers say hospitals as well as families should take note to maximise the benefits of the sunlight (stock)

HOW CAN SCIENTISTS TURN SUNLIGHT INTO FUEL?

Scientists have developed a way to transform sunlight into fuel that could lead to an 'unlimited source of renewable energy'.

Researchers from the University of Cambridge have done this by splitting water into hydrogen and oxygen.

They did this through using a technique called semi-artificial photosynthesis that is based on the same process plants use to convert sunlight into energy.

Artificial photosynthesis has been around for decades but it has not yet been successfully used to create renewable energy.

This is because it relies on the use of catalysts, which are often expensive and toxic.

Researchers used natural sunlight to convert water into hydrogen and oxygen using a mixture of biological components and manmade technologies.

Researchers reactivated a process in algae that has been dormant for millennia.

They did this using hydrogenase, an enzyme present in algae that is capable of reducing protons into hydrogen.

'During evolution, this process has been deactivated because it wasn't necessary for survival but we successfully managed to bypass the inactivity to achieve the reaction we wanted – splitting water into hydrogen and oxygen', said Katarzyna Sokół, first author and PhD student at St John's College.

Ms Sokół hopes the findings will enable new innovative model systems for solar energy conversion to be developed.

Dust left in the dark contained more bacteria from human skin and less from outside.

The results suggest sunlight is a 'bactericide' which can destroy bugs, according to the study published in the journal Microbiome.

It may cause a chemical reaction which eradicates the micro-organisms.

Scientists monitored the dust for 90 days to reflect how long it typically stays in our homes before being cleaned away during housework.

Dr Fahimipour said: '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.

'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.

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