(1) This article from the New York post ranks popular face masks from most effective to least. Kirsten Fleming and Catherine Kast reference research done by Duke University. They describe the setup of the experiment as an individual repeats a phrase several times in the direction of a laser, a cellphone camera records the respiratory droplets produced and an algorithm calculates how many respiratory droplets escaped the mask. The article ranked masks from best to worst with N95 and surgical masks as the best, bandanas and neck gaiters as the worst, with several variations of masks made with cotton and/or synthetic material in between. The authors express a few times that outstanding variables like low loud someone speaks or how well the mask fits may affect the amount of respiratory droplets that pass through.
(2) This article from Duke University investigates facemask efficacy in filtering respiratory droplets expelled during speech with a replicable setup. The authors address that this study was designed to be a quick and affordable way to estimate the efficacy of a mask, that should be expanded upon. They identify the need for further research as they only studied 1-4 speakers per mask, did not account for speaker volume or speech patterns, and were limited by the camera quality (can only detect droplets larger than 0.5um). The results show masks ranked from medical N95 and surgical masks, to different varieties of cotton masks, and on to bandanas, no mask , and fleece gaiters. They represent their data in a figure showing the time evolution of droplet count and with box and whisker plots comparing the mean and standard deviation of each mask’s efficacy over 10 trials. They also include a figure regarding the light scattering properties of droplets, which reflected aspects of their setup.
(3) I think the science was used well in this NY Post article. The authors presented the overall findings of the data and accurately ranked the masks from best to worst. The authors did not discuss the variability of each mask or present the actual data (mean and standard deviation of respiratory droplets that the mask transmitted). However, they did a good job of ranking the masks and acknowledging that extraneous variables (like different speakers, speech volumes, etc) likely influenced results and could explain a lot of the variability among similar cotton masks. Overall I think it was important that the authors stressed the need to wear masks to prevent the spread of Covid-19 while acknowledging that most of the types of masks commonly worn proved to be reasonably effective (except gaiters and bandanas).