Hello and welcome to more or less on the BBC World Service, with a program that explores

and sometimes deploys the numbers all around us in the news and in life.

9. Tim Halford

Now, loyal listener Arlen Gregorius, who might admit maybe loyal only because she's a

colleague at BBC Radio Current Affairs, but who cares, loyal is loyal. Anyway, loyal listener Arlen

Gregorius has been in touch to ask whether we shouldn't all be making our own face masks

to help stop the spread, the coronavirus. She's a keen crafter and can often be spotted in

home spun office chic and now she's itching to put her needlework skills to use for the greater good.

So should she? Ruth Alexander has been looking into it. How Ruth?

Hi Tim. There is a lot of disagreement about how good the evidence is or isn't for face masks

for the general public. For medical staff, it's a no-brainer. They should have PPE,

protective equipment, but that goes way beyond a homemade cloth mask. It'll mean a visor, gloves,

gown, high quality surgical mask or even full-blown respirator and maybe more. But for the rest of us,

it's debatable how useful masks might be. Okay, well let's hear the arguments.

Medical data scientist Jeremy Howard of the University of San Francisco is pro-mask. He started

a campaign in the US, hashtag MasksforAll and he's clear that we should all be wearing face masks

to achieve great protection not so much as individuals, but at a population level. And he began

by looking at the data coming out of affected countries. I started diving in and I discovered that

in regions surrounding the original epicenter of the pandemic, which is China, of course.

There are regions around that Mongolia, Taiwan, Hong Kong, and South Korea that have been

hit hundreds of times less than other, similar sized countries. And furthermore, these countries

are not currently in the kind of lockdown or shoulder-and-place enforced by law that we're seeing

...