Scientists identify the best (and worst) Covid-19 masks

Mask wearing is an essential part of controlling the spread of coronavirus.

New research shows that some masks are far more effective than others.

The team used a laser-beam experiment to show how many droplets were released when people spoke the phrase "stay healthy, people" five times in ten seconds.

While wearing no mask (a control), one participant released about 960 droplets.

The amounts of droplets varied — some speakers only released 200.

Other studies suggest that 1 minute of speaking can release over 1,000 droplets.

Fleeces (gaiters) released more droplets (orange) than wearing no mask at all (green).

The team suggests that's because large droplets are broken up into smaller droplets by the gaiter.

Key to understanding this result is knowing that they found wearing a gaiter to be "counterproductive" in this experiment on just one person. More robust research is needed to make any conclusions about this type of mask.

Bandanas released about 50 percent as many droplets compared to wearing no mask at all.

Fitted N95 masks released less than 0.1 percent of droplets (orange, not visible) that would have been spewed if no mask was worn (green).

Surgical masks released only about 1 percent of droplets (orange) that would have been released if no mask was worn (green).

Cotton-polypropylene-cotton masks and 2-layer polypropylene apron masks both only allowed between 5 percent and 10 percent of the droplets through, compared to wearing no mask.

Cotton-polypropylene-cotton masks (light green) took 3rd place.

2-layer polypropylene apron masks (dark green) took 4th place.

Several different varieties of cotton masks, valved N95 masks, and knitted masks all allowed between 10 percent and 50 percent of droplets to escape.

Knitted masks fared the worst of this group (red, 12th place).

Two-layer cotton pleated masks (yellow, 5th and 6th place) performed the best.