Neck warmer for COVID-19 worse than not covering the face at all

People who have tried exercising outdoors while wearing a mask other than a neck warmer have come to the unsurprisingly finding that they have more trouble breathing. The neck warmer, made of a very thin and stretchy material, solves this problem, allowing users to have as much air as they need. Unfortunately, investigators at Duke University also found that neck guards offer no protection against coronavirus disease 2019 (COVID-19) and that wearing them can be worse than not wearing a face mask to stop the spread of the virus. The results were published in a study in Scientific advances.

Neck guards weren’t the only face coverings tested: a total of 14 were analyzed, from N95s (unsurprisingly found to be the most effective at containing the spread of COVID-19) to bandanas (not much more effective than neck protectors, according to the study).

As a university press release explains, the baffling discovery about neck guards came from a professor at Duke who wanted to know which face coverings are most effective. This professor needed this information in his efforts to provide masks and other facial coverings to an underserved population in Durham, North Carolina.

Enter Martin Fischer, chemist and physicist at the university. He built a simple test device using a laser (you can find them online for around $ 200), a cell phone camera, a cardboard box, and a lens. Fisher was able to track the particles emitted by individuals.

Investigators noted that “In short, an operator wears a face mask and speaks in the direction of a laser beam extended inside a dark enclosure. The droplets that propagate through the laser beam scatter the light, which is recorded with a cell phone camera. A simple computer algorithm is used to count the droplets in the video. “

After testing the 14 masks considered commonly available, they found some fascinating tests. First and – again – unsurprisingly, N95 respirators and surgical masks provided the most droplet protection / containment.

The cotton masks have worked quite well, which is reassuring as they are used frequently in the community. Two important results were also reported: “We noticed that speaking through some masks (especially the fleece of the neck) seemed to disperse the larger droplets into a multitude of smaller droplets… which explains the apparent increase in the number of droplets compared to no mask in this case. Since smaller particles are airborne longer than larger droplets (larger droplets sink faster), using such a mask could be counterproductive. Additionally, the performance of the N95 valve mask is likely affected by the exhalation valve, which opens for a strong outward airflow. The focus on N95 valves is a good reminder of the role of exhaust valves and how they not only provide poor source control, but also cannot be used in sterile environments.

The results of this study are not only informative in terms of the potential amplification effected by fleece masks, but reiterate the importance for infection prevention practitioners to make informed decisions for the community in terms of masks. Ideally, surgical masks would be useful as they provide protection not only to those around the wearer, but also to the person wearing them.

As hospitals consider more sustainable approaches to ensure masking compliance among visitors, but also want to support employees beyond the walls of the healthcare facility, cloth masks could be a viable option. Plus, providing the public with better advice on masks that offer more protection without impacting healthcare supply chains is beneficial for everyone. It is extremely important to better understand the effectiveness of widely available masks.