Tag: airborne transmission

An ‘Invisible Mask’ Air Curtain that Kills Viruses, Blocks 99.8% of Aerosols

Taza Aya’s Worker Wearable Protection device keeps airborne virus particles from reaching a workers mouth and nose with an air curtain. That air is pre-treated to kill any viruses. Image credit: Jeremy Little, Michigan Engineering

An air curtain shooting down from the brim of a hard hat can prevent 99.8% of aerosols from reaching a worker’s face. The technology, created by University of Michigan startup Taza Aya, potentially offers a new protection option for workers in industries where respiratory disease transmission is a concern.

Independent, third-party testing of Taza Aya’s device showed the effectiveness of the air curtain, curved to encircle the face, coming from nozzles at the hat’s brim. But for the air curtain to effectively protect against pathogens in the room, it must first be cleansed of pathogens itself. Previous research by the group of Taza Aya co-founder Herek Clack, U-M associate professor of civil and environmental engineering, showed that their method can remove and kill 99% of airborne viruses in farm and laboratory settings.

“Our air curtain technology is precisely designed to protect wearers from airborne infectious pathogens, using treated air as a barrier in which any pathogens present have been inactivated so that they are no longer able to infect you if you breathe them in,” Clack said. “It’s virtually unheard of – our level of protection against airborne germs, especially when combined with the improved ergonomics it also provides.”

Fire has been used throughout history for sterilisation, and while we might not usually think of it this way, it’s what’s known as a thermal plasma. Nonthermal, or cold, plasmas are made of highly energetic, electrically charged molecules and molecular fragments that achieve a similar effect without the heat. Those ions and molecules stabilize quickly, becoming ordinary air before reaching the curtain nozzles.

Taza Aya’s prototype features a backpack, weighing roughly 10 pounds (4.5kg), that houses the nonthermal plasma module, air handler, electronics and the unit’s battery pack. The handler draws air into the module, where it’s treated before flowing to the air curtain’s nozzle array.

Taza Aya’s progress comes in the wake of the COVID pandemic and in the midst of a summer when the U.S. Centers for Disease Control and Prevention have reported four cases of humans testing positive for bird flu. During the pandemic, agriculture suffered disruptions in meat production due to shortages in labour, which had a direct impact on prices, the availability of some products and the extended supply chain.

In recent months, Taza Aya has conducted user experience testing with workers at Michigan Turkey Producers in Wyoming, Michigan, a processing plant that practices the humane handling of birds. The plant is home to hundreds of workers, many of them coming into direct contact with turkeys during their work day.

To date, paper masks have been the main strategy for protecting employees in such large-scale agriculture productions. But on a noisy production line, where many workers speak English as a second language, masks further reduce the ability of workers to communicate by muffling voices and hiding facial clues.

“During COVID, it was a problem for many plants – the masks were needed, but they prevented good communication with our associates,” said Tina Conklin, Michigan Turkey’s vice president of technical services.

In addition, the effectiveness of masks is reliant on a tight seal over the mouth and noise to ensure proper filtration, which can change minute to minute during a workday. Masks can also fog up safety goggles, and they have to be removed for workers to eat. Taza Aya’s technology avoids all of those problems.

As a researcher at U-M, Clack spent years exploring the use of nonthermal plasma to protect livestock. With the arrival of COVID in early 2020, he quickly pivoted to how the technology might be used for personal protection from airborne pathogens.

In October of that year, Taza Aya was named an awardee in the Invisible Shield QuickFire Challenge – a competition created by Johnson & Johnson Innovation in cooperation with the U.S. Department of Health and Human Services. The program sought to encourage the development of technologies that could protect people from airborne viruses while having a minimal impact on daily life.

“We are pleased with the study results as we embark on this journey,” said Alberto Elli, Taza Aya’s CEO. “This real-world product and user testing experience will help us successfully launch the Worker Wearable in 2025.”

Source: University of Michigan

Infection-preventing Air Treatment Systems may All Just be Hot Air

Photo by Brittany Colette on Unsplash

Air filtration systems do not reduce the risk of picking up viral infections, according to new research from the University of East Anglia. A new study published in Preventive Medicine reveals that technologies designed to make social interactions safer in indoor spaces are not effective in the real world. The team studied technologies including air filtration, germicidal lights and ionisers.

They looked at all the available evidence but found little to support hopes that these technologies can make air safe from respiratory or gastrointestinal infections.

Prof Paul Hunter said: “Air cleaners are designed to filter pollutants or contaminants out of the air that passes through them.

“When the Covid pandemic hit, many large companies and governments – including the NHS, the British military, and New York City and regional German governments – investigated installing this type of technology in a bid to reduce airborne virus particles in buildings and small spaces.

“But air treatment technologies can be expensive. So it’s reasonable to weigh up the benefits against costs, and to understand the current capabilities of such technologies.” 

The research team studied evidence about whether air cleaning technologies make people safe from catching airborne respiratory or gastrointestinal infections. They analysed evidence about microbial infections or symptoms in people exposed or not to air treatment technologies in 32 studies, all conducted in real world settings like schools or care homes. So far none of the studies of air treatment started during the Covid era have been published.

‘Disappointing’ findings

Lead researcher Dr Julii Brainard said: “The kinds of technologies that we considered included filtration, germicidal lights, ionisers and any other way of safely removing viruses or deactivating them in breathable air.

“In short, we found no strong evidence that air treatment technologies are likely to protect people in real world settings.

“There is a lot of existing evidence that environmental and surface contamination can be reduced by several air treatment strategies, especially germicidal lights and high efficiency particulate air filtration (HEPA).  But the combined evidence was that these technologies don’t stop or reduce illness.

“There was some weak evidence that the air treatment methods reduced likelihood of infection, but this evidence seems biased and imbalanced. We strongly suspect that there were some relevant studies with very minor or no effect but these were never published.

“Our findings are disappointing – but it is vital that public health decision makers have a full picture. Hopefully those studies that have been done during Covid will be published soon and we can make a more informed judgement about what the value of air treatment may have been during the pandemic.”

Source: University of East Anglia

COVID Variants Evolving to Improved Airborne Transmission

Source: Fusion Medical Animation on Unsplash

A new study found that people infected with SARS-CoV-2 shed significant numbers of virus particles in their breath – and those infected with the Alpha variant put 43 to 100 times more virus into the air than people infected with the original strains. 

The researchers also found that loose-fitting cloth and surgical masks reduced the amount of virus that gets into the air around infected people by about half. The study was published in Clinical Infectious Diseases.

“Our latest study provides further evidence of the importance of airborne transmission,” said Dr Don Milton, Professor, Environmental Health, University of Maryland School of Public Health. “We know that the Delta variant circulating now is even more contagious than the Alpha variant. Our research indicates that the variants just keep getting better at traveling through the air, so we must provide better ventilation and wear tight-fitting masks, in addition to vaccination, to help stop spread of the virus.”

The numbers of airborne virus particles coming from infections with the Alpha variant (the dominant strain circulating at the time this study was conducted) was much more (18 times more) than could be explained by the increased amounts of virus picked up in nasal swabs and saliva. 
Doctoral student Jianyu Lai, a lead author of the study, explained: “We already knew that virus in saliva and nasal swabs was increased in Alpha variant infections. Virus from the nose and mouth might be transmitted by sprays of large droplets up close to an infected person. But, our study shows that the virus in exhaled aerosols is increasing even more.” These major increases in airborne virus from Alpha infections occurred before the arrival of the Delta variant, suggesting that the virus is evolving to have improved airborne transmission.

To test the efficacy of masks in reducing transmission, the researchers measured how much SARS-CoV-2 is exhaled into the air with and without wearing a cloth or surgical mask. They found that face coverings significantly reduced virus-laden particles in the air around the person with COVID by about 50%.

Co-author Dr Jennifer German said, “The take-home messages from this paper are that the coronavirus can be in your exhaled breath, is getting better at being in your exhaled breath, and using a mask reduces the chance of you breathing it on others.” This means that a layered approach to control measures (including improved ventilation, increased filtration, UV air sanitation, and tight-fitting masks, in addition to vaccination) is critical to protect people in public-facing jobs and indoor spaces.

Source: University of Maryland