Nanofiber Media Shows 99.9 % Virus Capture Efficiency

Virus Found on HEPA Filters in Schools in California

Indian Government Issues Double Masking Guidelines

American University Professor Says Good School Ventilation is a Long-Term Benefit

Transformational Period for Indoor Air Quality

Fauci Says Public is Misinterpreting CDC Mask Guidelines

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Nanofiber Media Shows 99.9 % Virus Capture Efficiency

A recent study conducted by investigators from the University of California at Riverside, in collaboration with George Washington University, discovered that a filter made from polymer nano threads can capture up to 99.9% of Coronavirus aerosols.

Results from the study were published in the journal Environmental Science & Technology Letters.

"Our work is the first study to use coronavirus aerosols for evaluating filtration efficiency of face masks and air filters," Yun Shen, a corresponding author on the study said. "Previous studies have used surrogates of saline solution, polystyrene beads, and bacteriophages -- a group of viruses that infect bacteria."

For the study, the team of investigators sent high electrical voltage through a drop of liquid polyvinylidene fluoride to spin threads about 300 nanometers in diameter and created a nanofiber filter. The technique is known as electrospinning and can be a cheap way to mass produce the filters for personal protective equipment and air filtration systems.

They then compared the nanofiber filters against surgical masks, cotton masks and neck gaiters to see how well each of them prevented airborne aerosols.

Most studies up until now have used other materials to mimic both the size and behavior of coronaviruses, but the investigators in this study uses an aerosolized saline solution and an aerosol that contained a coronavirus from the same family as COVID-19.

Findings from the study showed that the cotton mask and neck gaiter remove around 45% to 73% of the aerosols, while the surgical mask removed around 98%. However, the nanofiber filter removed almost all of the coronavirus aerosols, just about 99.9%.

"Electrospinning can advance the design and fabrication of face masks and air filters," Shen said. "Developing new masks and air filters by electrospinning is promising because of its high performance in filtration, economic feasibility, and scalability, and it can meet on-site needs of the masks and air filters."

 

Virus Found on HEPA Filters in Schools in California

Kids are back in class with safety protocols like physical distancing, masking, and plastic barriers throughout classrooms. Even so, newly developed surveillance swabbing detected the coronavirus in HEPA filters in two Davis classrooms in the last two weeks: one at Korematsu Elementary and the other at North Davis Elementary.

“That’s really scary, but I’m glad they can trace it back,” said one parent.

The testing is part of a pilot program started last week with Davis Joint Unified School District and Healthy Davis Together, with UC Davis conducting the testing. The goal of the system is to identify a problem before it can spread.

“It’s basically providing passive testing in place of each child getting tested every single day because it’s monitoring any viral activity in the whole room,” said Dr. Sheri Belafsky.

Belafsky is the medical director for Healthy Davis Together and she oversees medical surveillance for UC Davis Public Health. She says students have been tested and no coronavirus has been detected. How is that possible?

“From the time the swab was collected and processed in the lab, the results found and children tested, there is a period of several days and that person’s infection could be waning,” she said.

She said all HEPA filters that tested positive were replaced and those have since tested negative. More proof the threat is gone. That’s good news for parents who know with kids, the fight against the spread of the coronavirus is a daily battle.

“They end up being close at lunch with no masks. It’s hard for kids to keep their mask on.”

Belafsky says district staff will continue to swab classroom filters weekly.

“By having an air filter in place and swabbing, we basically have a sentinel,” she said.

The district is reminding parents to sign waivers so their children can immediately be tested if this is an issue again. This type of HEPA swabbing has been done in hospitals, but not schools. They plan to expand this pilot program to include wastewater monitoring in the coming months.

 

Indian Government Issues Double Masking Guidelines

Even as India continues to fight a tough battle against a devastating second wave of the coronavirus, the central government has issued fresh guidelines on how to curb the spread of the virus. In the document, titled "Stop the Transmission, Crush the Pandemic," the government focuses on measures such as double masking, physical distancing, and proper ventilation arrangements. Here are more details on this.

Saliva and nasal discharge from an infected individual in the form of droplets and aerosols is the primary mode of coronavirus transmission, the Indian government's Principal Scientific Adviser K VijayRaghavan's office said in the guidelines today. Though droplets fall within two meters of an infected person, smaller aerosol particles can travel in the air up to 10 meters, according to the document.

You should wear a double layer mask or an N95 mask for maximum protection, the guidelines say. For double masking, prefer wearing a surgical mask and a tight-fitting cloth mask over it." Ideally, the surgical mask should be used only once, but when pairing, you can use it up to five times by leaving it in a dry place for seven days after one use."

Droplets emitted by an infected person can land on various surfaces and survive there for a long time, the advisory warned. It suggested frequent cleaning of high-contact points such as door handles, switches, taps, and chairs, etc., using disinfectants like phenyl and bleach.

Ventilation

The document also highlights the role of well-ventilated spaces in reducing the risk of coronavirus spread." Just as smells can be diluted from the air through opening windows and doors and using exhaust systems, ventilating spaces with improved directional air flow decreases the accumulated viral load in the air, reducing the risk of transmission," it said.

The placement of fans is crucial - they should not be placed where they can cause contaminated air to flow directly toward a person present in the room, according to the advisory. If the windows and doors of a room are closed, the exhaust fans must be turned on "to create the ideal airflow for maximum protection from indoor infection."

In indoor settings where air conditioners are turned on, doors/windows should be kept wide open so that clean air can enter from the outside and dilute the virus particles. Adding an exhaust fan is also recommended. “In offices, auditoriums, shopping malls etc. use of gable fan systems and roof ventilators are recommended. Frequent cleaning and replacement of filters is highly recommended," the advisory added.

Situation

India has been gripped by a ferocious second wave of the COVID-19 pandemic, reporting lakhs of new infections every day over the past few weeks. In the past 24 hours, the country logged 2,76,070 new coronavirus cases. With over 3,800 more fatalities, the death toll in India crossed 75,000 for this month and 2.87 lakh overall.

 

American University Professor Says Good School Ventilation is a Long-Term Benefit

“COVID-19 has changed the way we understand school building ventilation and its importance in keeping us safe from viruses and bacteria in the air. The pandemic has motivated many school leaders to invest in improvements to ventilation systems, but the benefits of investing in a safe learning environment extend far beyond protecting children from the coronavirus. The evidence I present below suggests that pollution exposure is not only a factor in student academic outcomes but also a major driver of inequality in outcomes between wealthier and lower-income children, and between white and nonwhite children.”

Claudia Persico

Assistant Professor - American University
Research Affiliate - IZA Institute of Labor Economics

Why is it so important to invest in school infrastructure now? There is evidence that school ventilation protects children from contracting COVID-19 and other viruses in schools. Research suggests that COVID-19 spreads in schools in situations where there are high case rates in the surrounding community, and children can still catch COVID-19 in school buildings that are not properly ventilated.

I recently released a study (with Kathryn Johnson) showing that higher air pollution can make people more likely to get sick with and die from COVID-19. Because air pollution harms the immune system, it can increase the likelihood of infection from airborne diseases. It also can lead existing cases of COVID-19 to become more severe by harming the immune systems of infected people. We used the variation in pollution caused by a rollback of environmental enforcement during the pandemic to estimate the effects of increased pollution on county-level COVID-19 deaths and cases. We find that counties with more Toxic Release Inventory (TRI) sites (local factories or federal plants that emit harmful classes of pollution) saw an 11.8% increase in air pollution on average following the Environmental Protection Agency’s (EPA’s) rollback of enforcement, compared to counties with fewer TRI sites. We also find that these policy-induced increases in air pollution are associated with a 53% increase in cases and a 10.6% increase in deaths from COVID-19.

In addition to providing some protection against illness, there is evidence that air filters, like those commonly used in modern HVAC systems, can limit children’s exposure to local air pollution. There is mounting evidence that air pollution can harm children’s development and academic outcomes. In another new paper, I (along with Joanna Venator) use detailed Florida public school data to assess how children’s outcomes change when a TRI site opens or closes within a mile of their school. The comparison group is composed of students attending schools between one and two miles away from a TRI site at the same time in the same zip code. We find that exposure to pollutants in schools has significant, negative impacts on test scores and being suspended or absent from school.

Note that the conditions we’re exploring in this study are not unique to Florida. There are currently about 21,800 TRI sites operating across the United States, and the EPA estimates that 59 million people (on average, about 19% of the population living in every state) live within one mile of a TRI site. Nearly 22% of all public schools were within one mile of a TRI facility in 2016, and these sites exist in both urban and rural areas.

In addition, over 6.4 million U.S. children attend public school within 250 meters of a major roadway. In another paper, I (along with David Simon and Jenni Heissel) compare students who have to switch from elementary to middle school or from middle school to high school as they progress through the school system. We compare children who switch from a school that is upwind from a highway to a school that is downwind of a highway and find that highway air pollution negatively affects students’ test scores, behavior, and absences.

We also know that air quality affects children’s performance on the day of the test. Because pollution might make children more disruptive, another recent study finds that exposure to pollution has spillover effects onto children who are not themselves exposed to pollution. Thus, pollution can affect schoolchildren’s outcomes both directly and indirectly.

The pandemic has also brought into sharp relief the consequences of social disparities, which is a common theme in the literature exploring environmental conditions and student outcomes. For example, children who attend school near a major highway are more likely to be low income or nonwhite than children attending school elsewhere. Low-income, Black and Latino children are also more likely to live near Superfund sites (the worst federal toxic waste sites) and to attend school near TRI sites. It is evident, therefore, how uneven exposure to pollutants along socioeconomic lines contributes to long-standing achievement gaps.

These socioeconomic differences extend to the quality of school facilities as well. According to the Government Accountability Office’s national survey of school districts, about 54% of public school districts need to update or replace multiple building systems or features in their schools, with heating, ventilation, or air conditioning being the most common system in need of attention. They also find that capital construction expenditures were on average $300 less per student in high-poverty districts ($719 per student) compared to low-poverty districts ($1,016 per student). This funding disparity reflects fewer resources to spend in spite of the greater needs, in most cases, of lower-income districts. Whereas wealthier districts can make up funding shortfalls from the state through raising local taxes, high-poverty districts are more likely to rely on state funding and have difficulty making up the difference in lean years.

How much might HVAC system upgrades in schools help? In a recent study, Gilraine finds that putting air purifiers in classrooms led to a 0.2 standard deviation increase in test scores for children, compared to children in local schools that did not get the air purifiers. (See here for Gilraine’s summary on Brookings’s Brown Center Chalkboard.) This is similar to the effect of small class sizes in the famed Tennessee STAR experiment. This suggests that air filtration, like that offered by modern HVAC systems, could improve children’s academic and behavioral outcomes long after the COVID-19 pandemic has concluded.

Low-income children stand to be impacted the most by improvements in air quality; there is evidence that their school buildings are in worse shape in many places and that they are more likely to live near sources of pollution.

Right now there is a debate over whether schools should be part of President Biden’s infrastructure bill. Some are concerned that spending on schools could be wasteful or unnecessary. However, the evidence suggests that upgrading school buildings would be both a timely and wise investment that is likely to pay dividends for years to come.

Transformational Period for Indoor Air Quality

Clean water in 1842, food safety in 1906, a ban on lead-based paint in 1971. These sweeping public health reforms transformed not just our environment but expectations for what governments can do.

Now it is time to do the same for indoor air quality, according to a group of 39 scientists. In a manifesto of sorts published Thursday in the journal Science, the researchers called for a “paradigm shift” in how citizens and government officials think about the quality of the air we breathe indoors.

The timing of the scientists’ call to action coincides with the nation’s large-scale reopening as coronavirus cases steeply decline Americans are anxiously facing a return to offices, schools, restaurants and theaters — exactly the type of crowded indoor spaces in which the coronavirus is thought to thrive.

There is little doubt now that the coronavirus can linger in the air indoors, floating far beyond the recommended 6 feet of distance, the experts declared. The accumulating research puts the onus on policymakers and building engineers to provide clean air in public buildings and to minimize the risk of respiratory infections, they said.

“We expect to have clean water from the taps,” said Lidia Morawska, the group’s leader and an aerosol physicist at Queensland University of Technology in Australia. “We expect to have clean, safe food when we buy it in the supermarket. In the same way, we should expect clean air in our buildings and any shared spaces.”

Meeting the group’s recommendations would require new workplace standards for air quality, but the scientists maintained that the remedies do not have to be onerous. Air quality in buildings can be improved with a few simple fixes, they said: adding filters to existing ventilation systems, using portable air cleaners and ultraviolet lights — or even just opening the windows where possible.

Morawska led a group of 239 scientists who last year called on the World Health Organization to acknowledge that the coronavirus can spread in tiny droplets, or aerosols, that drift through the air. The WHO had insisted that the virus spreads only in larger, heavier droplets and by touching contaminated surfaces, contradicting its own 2014 rule to assume all new viruses are airborne.

The WHO conceded on July 9 that transmission of the virus by aerosols could be responsible for “outbreaks of COVID-19 reported in some closed settings, such as restaurants, nightclubs, places of worship or places of work where people may be shouting, talking or singing,” but only at short range.

The pressure to act on preventing airborne spread has recently been escalating. In February, more than a dozen experts petitioned the Biden administration to update workplace standards for high-risk settings like meatpacking plants and prisons, where COVID outbreaks have been rampant.

Last month, a separate group of scientists detailed 10 lines of evidence that support the importance of airborne transmission indoors.

On April 30, the WHO inched forward and allowed that in poorly ventilated spaces, aerosols “may remain suspended in the air or travel farther than 1 meter (long-range).” The Centers for Disease Control and Prevention, which had also been slow to update its guidelines, recognized last week that the virus can be inhaled indoors, even when a person is more than 6 feet away from an infected individual.

“They have ended up in a much better, more scientifically defensible place,” said Linsey Marr, an expert in airborne viruses at Virginia Tech and a signatory to the letter.

“It would be helpful if they were to undertake a public service messaging campaign to publicize this change more broadly,” especially in parts of the world where the virus is surging, she said. For example, in some East Asian countries, stacked toilet systems could transport the virus between floors of a multistory building, she noted.

More research is also needed on how the virus moves indoors. Researchers at the Department of Energy’s Pacific Northwest National Laboratory modeled the flow of aerosol-size particles after a person has had a five-minute coughing bout in one room of a three-room office with a central ventilation system. Clean outdoor air and air filters both cut down the flow of particles in that room, the scientists reported in April.

But rapid air exchanges — more than 12 in an hour — can propel particles into connected rooms, much as secondhand smoke can waft into lower levels or nearby rooms.

“For the source room, clearly more ventilation is a good thing,” said Leonard Pease, a chemical engineer and lead author of the study. “But that air goes somewhere. Maybe more ventilation is not always the solution.”

In the United States, the CDC’s concession may prompt the Occupational Safety and Health Association to change its regulations on air quality. Air is harder to contain and clean than food or water. But OSHA already mandates air quality standards for certain chemicals. Its guidance for COVID does not require improvements to ventilation, except for health care settings.

Ventilation is really built into the approach that OSHA takes to all airborne hazards,” said Peg Seminario, who served as director of occupational safety and health for the AFL-CIO from 1990 until her retirement in 2019. “With COVID being recognized as an airborne hazard, those approaches should apply.”

In January, President Joe Biden directed OSHA to issue emergency temporary guidelines for COVID by March 15. But OSHA missed the deadline; its draft is reportedly being reviewed by the White House’s regulatory office.

In the meantime, businesses can do as much or as little as they wish to protect their workers. Citing concerns of continued shortages of protective gear, the American Hospital Association, an industry trade group, endorsed N95 respirators for health care workers only during medical procedures known to produce aerosols, or if they have close contact with an infected patient. Those are the same guidelines the WHO and the CDC offered early in the pandemic. Face masks and Plexiglas barriers would protect the rest, the association said in March in a statement to the House Committee on Education and Labor.

Fauci Says Public is Misinterpreting CDC Mask Guidelines

Anthony S. Fauci, the government’s leading infectious-disease expert, told Axios that the public is misinterpreting the Centers for Disease Control and Prevention’s announcement last week that fully vaccinated people can go without masks indoors.

“I think people are misinterpreting, thinking that this is a removal of a mask mandate for everyone. It’s not,” he told Axios. “It’s an assurance to those who are vaccinated that they can feel safe, be they outdoors or indoors.”

Fauci emphasized that the health agency did not explicitly tell unvaccinated people to go without masks but instead communicated to vaccinated individuals that they will not get infected indoors or outdoors.

“People either read them quickly or listen and hear half of it. They are feeling that we’re saying: ‘You don’t need the mask anymore.’ That’s not what the CDC said,” he told the news outlet.

Reaction to the CDC’s guidance has been applauded by those who say it shows the efficacy of vaccinations against the coronavirus and criticized by those who say it is too soon to forgo masks.