Face masks, even homemade ones, are effective in reducing the spread of coronavirus and should be used by everyone, according to a new Oxford study.

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The Leverhulme Centre for Demographic Science report, published on July 7, investigated the effectiveness of different face mask types as well as an international comparison of policies and behaviour over usage.

'Unclear and inconsistent'

Professor Melinda Mills, director of the Leverhulme Centre and author of the study said: "The evidence is clear that people should wear masks to reduce virus transmission and protect themselves, with most countries recommending the public to wear them.

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"Yet clear policy recommendations that the public should broadly wear them has been unclear and inconsistent in some countries such as England."

The Oxford study shows that, just days after the World Health Organisation announced the pandemic in mid-March, many countries (some 70) immediately recommended mask wearing.

That number grew to more than 120 countries with most requiring mask wearing everywhere in public.

Asian countries with previous experiences of the SARS outbreak saw early and virtually universal mask usage.

Professor Mills said in the UK: "The public is confused about wearing face masks and coverings because they have heard the scientific evidence is inconclusive and advice from the WHO and others has changed.

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"People also feared they might be competing with scarce PPE resources and they need clear advice on what to wear, when to wear them and how to wear them."

Around the world, the study finds, next to hand washing and social distancing, face masks and coverings are one of the most of widely adopted non-pharmaceutical interventions for reducing the transmission of respiratory infections.

What type of face mask? 

But, the study shows, some coverings are not as effective as others.

Loosely woven fabrics, such as scarves have been shown to be the least effective.

Professor Mills said: "Attention must also be placed on how well it fits on the face; it should loop around the ears or around the back of the neck for better coverage.

"The general public does not need to wear surgical masks or respirators.

"We find that masks made from high quality material such as high-grade cotton, multiple layers and particularly hybrid constructions are effective.

"For instance, combining cotton and silk or flannel provide over 95 per cent filtration, so wearing a mask can protect others."

The report also finds that wearing a cotton mask protects the mask wearer as well.

UK behind Europe and US

Professor Mills added: "There is a general assumption that countries such as the UK, which have no culture or history of mask wearing, will not rapidly adopt them.

"But this just doesn’t hold when we look at the data. As of late April, mask-wearing was up to 84 per cent in Italy, 66 per cent in the US and 64 per cent in Spain, which increased almost immediately after clear policy recommendations and advice was given to the public."

The study concludes that public communications must be 'clear, consistent and transparent' with inconsistent information leading to scepticism and lowering usage.

It added face masks in the UK have had a very low uptake, with around 25 per cent as of late April.