ASU researcher tests face mask efficiency before and after sterilization

June 16, 2020

Protective face masks are key to Arizona State University and other schools and organizations reopening because their use significantly decreases coronavirus spread. Some masks, in light of recent shortages, are being sterilized to allow reuse.

Sterilization, however, may alter mask structure and therefore the effectiveness of the mask’s ability to block small droplets and aerosols. Airborne particles and droplets, from a few nanometers to a few microns in size, are the research focus of School of Molecular Sciences Professor Pierre Herckes. School of Molecular Sciences graduate student researcher Zhaobo Zhang tests the effectiveness of masks after sterilization. Download Full Image

Herckes and his graduate student researcher, Zhaobo Zhang, were testing personal protective equipment (PPE) mask efficiency to trap nanoparticles in the semi-conductor industry prior to the COVID-19 outbreak. After the outbreak, they were approached by several groups to test mask efficiency before and after sterilization. Sterilization methods included treatment with ultraviolet (UV) light, ozone, or peroxide vapors. Before and after each of these sterilization methods, Herckes and Zhang tested the efficiency of masks to trap droplets and aerosols.

“What we found was there was not a significant decrease in mask efficiency before and after treatment," Herckes said. "However, further testing needs to be done to determine the effect of multiple treatments on the structure of mask materials.”

Herckes notes that their testing methods differ from National Institute for Occupational Safety and Health methods, but nevertheless provide important results.

Herckes is co-investigator with ASU engineering professor Paul Westerhoff on a recently funded National Science Foundation grant, “Disinfection and Reuse of Health-Care Worker Facial Masks to Prevent Infection coronavirus disease.” This grant allows Westerhoff and Herckes to test for change in mask efficiency after repeated UV-light exposure.

READ MORE: ASU rapidly engineers solution for medical staff battling COVID-19

“This research is important because we know very little about how UV-light modifies the molecular structure of protective masks,” Herckes said. Their work will also allow them to determine mask efficiency based on particle size and charge.

Large droplets, such as those produced when someone coughs or sneezes, are trapped to a great degree by a mask, and these droplets don’t travel as far as smaller droplets. Smaller droplets, however, are also capable of carrying coronavirus particles. Coronavirus particles are also transmitted by smaller particles, such as those produced by talking or breathing. These small droplets stay in the air much longer than large droplets, and they are inhaled more deeply into your lungs.

“Wear a mask, because it not only protects you, but it protects others,” Herckes said.

Protection from a mask is greatest when it is worn properly.

“Wearing a mask below your nose allows you to inhale and exhale droplets, so cover your nose with the mask, and make sure it fits properly around your face so there isn’t leakage from the sides,” he said. If air goes around the mask, it’s not effectively trapping particles.

Herckes also advises that you minimize touching your mask once it’s on.

“Your mask should be comfortable and not restrict air flow significantly," he said. "When you touch your mask, you are transmitting contaminants from your hands to your mask, and from your mask to your hands. More importantly, the mask will trap airborne virus particles, so you will be transferring these trapped particles to your hands, and then from your hands to whatever you touch, possibly your face, eyes and mouth.”

Washing your hands and wearing your mask are both important steps to staying healthy and reducing the spread of coronavirus.

James Klemaszewski

Science writer, School of Molecular Sciences


How media mistakes threaten global shark survival

ASU researcher tracks pattern of media miscues that misleads the public about shark conservation policies

June 17, 2020

Sharks are among the most threatened animals in the world, and more people than ever now want to help. But a deep analysis of news coverage of shark conservation issues over 10 years reveals an alarming pattern of inaccurate reporting. This misinformation results in broad misunderstandings of the true issues among both media consumers and policymakers.

David Shiffman, a marine conservation biologist at Arizona State University's New College of Interdisciplinary Arts and Sciences, led a team that analyzed nearly 2,000 media articles dating back to 2008. The analysis reveals that worldwide media coverage of shark conservation topics is biased and inaccurate, omitting or misrepresenting key facts and not reporting on expert-backed solutions that have scientific data demonstrating their effectiveness. Hammer head shark just below surface of the water A great hammerhead shark Sphyrna lewini swims away after a research workup. These iconic sharks received more conservation-relevant media attention over the past decade than any other species of shark, according to an ASU analysis of how shark conservation media is portrayed in the global popular press. Photo credit: Jacob Jerome, Field School, used with permission. Download Full Image

“Sharks face many threats, and there are many available policy solutions to address those threats. However, you wouldn’t know that from reading newspaper coverage of this important and complex issue,” Shiffman said.

Examples of media misinformation include an overemphasis of threats, such as the shark fin trade verses the shark meat trade, which is a major and growing threat that’s less well understood. This skew in coverage has led in part to shark fin trade bans despite no evidence that these trade bans actually help sharks. The research notes that shark finning has been illegal in the United States since the 1990s, an important point that is often confused in media coverage of these issues.

Media coverage also dramatically under-reports on truly endangered shark species in favor of well-known species, such as great white sharks. Critically endangered species of sharks were mentioned only 20 times in nearly 2,000 articles.

“Our analysis reveals major issues with factual inaccuracy, bias and omission of key facts in the last decade of media coverage of shark conservation — and that means that many people who want to help don’t really understand the problem or which solutions are most effective to solve the problem,” Shiffman said.

Shiffman’s research paper, “Inaccurate and biased global media coverage underlies public misunderstanding of shark conservation threats and solutions,” is now published in the open access journal iScience, which focuses on interdisciplinary scientific research. The paper also includes an extensive introduction to scientific facts about shark conservation, written explicitly for nonexpert audiences and journalists wishing to more thoroughly understand this issue.

Richard Holland

Director Marketing and Communications, New College of Interdisciplinary Arts and Sciences