Transcript for Sheriff prohibits deputies from wearing masks to work
And you heard that urgent warning from the head of the CDC about wearing masks. Today a sheriff in Florida ordering deputies not to wear masks. And tonight here, a new study. Researchers in the lab, putting masks to the test. Which ones do they believe work best, and which do little to nothing at all? Here's ABC's Marcus Moore with the results. Reporter: Tonight, as more businesses and local governments are requiring masks, one Florida sheriff is banning them. Marion county sheriff Billy woods is prohibiting his deputies from wearing masks at work and visitors to the sheriff's office, too. While there are exceptions, including jails, hospitals or dealing with suspected covid patients, the sheriff says the policy is to "Ensure there is clear exhume case and for identification purposes." The move comes after the county's largest town, Ocala, recently passed a mandate, but the mayor vetoed it. The CDC says face masks -- which stop droplets of saliva -- are a front line defense against the spread of covid-19. Researchers from duke university used lasers to better visualize how well different masks stop those droplets. Surgical mask, trial one. Go. Stay healthy, people. Reporter: The more particles visible in the light, the less effective the mask. Though they only ran the test once, their study found the fitted n-95 mask, the surgical mask and the poly-cotton mask did best. This one here is fleece. You see lots of little particles. Reporter: Researchers said the fleece gaiter they tested actually resulted in tinier particles being released than speaking without a mask. These little droplets could be problematic, because they have an easier time being carried away by air. Reporter: But experts don't know whether tiny droplets necessarily increase the chance of transmitting the virus. David, it's important to stress that this was a limited study. Researchers still don't know what size or how many particles it takes to make someone sick. The bottom line is health experts agree, any mask is better than no mask. David? All right, Marcus Moore tonight. Marcus, thank you.
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