McIlvaine Coronavirus Market Ale

Mask Fit is Critical to Success Against COVID But Most Are Not Aware of This

The Value of Tight Fitting Effective Masks Demonstrated by White House Events

On October 10 there was a rally in the Rose Garden of the White House. An earlier event celebrating the Supreme Court nomination will likely result in 100 new coronavirus infections. This includes the original 13 directly tied to the event and then others who will be infected later by the super spreading. The October 10 event will probably result in 200 infections. Here is why.

Parameters	Supreme Court Event	Oct 10 Event	Cases Prevented if Implemented
# of people in attendance	100	400	200 Total Preventable
Long Distance Travel	Yes	Yes
Social Distancing	No	No	90
N95 Masks	No	No	180
Surgical Masks	No		90
Cloth Masks	No		40

Many of the people traveled by air to the event. There was no social distancing. Some people were unmasked but many had cloth masks. Even if some were wearing surgical masks they were probably loose fitting. If everyone had been wearing efficient tight fitting masks, there may be only 20 cases resulting from the event of which only four would be directly from the event. If everyone had been wearing surgical masks with some effort at obtaining a good fit the cases would be reduced to 110 and 90 deaths prevented.

If everyone had had a loose fitting cloth mask probably only 40 cases would have been avoided and there would still be 160.

This type of behavior is why as of today the U.S. has had 8 million cases and 220,000 deaths. The latest models show that we are headed toward 400,000 deaths by January 1. These additional 180,000 deaths could be reduced by 80% with proper use of tight fitting N95 masks.

The net benefit to U.S. citizens including both economic and quality of life will be 180,000 x $20 million = $3.6 trillion. This is a net benefit from which an expenditure of $12 billion for highly efficient masks is already deducted.

Mask Fit is Critical to Success Against COVID But Most Are Not Aware of This

A new article in Nature addresses many of the issues on masks which McIlvaine has been investigating. However, the problem is the lack of recognition that a 10 micron droplet impinging on a mask will evaporate or be converted into small droplets. In any case the ultimate salts which contain the virus will be just a small fraction of a micron in size. Much of previous mask efficiency analysis was focused on particles. A 2 micron particle adhering on a mask fiber will stay there. A droplet will evaporate. So we have two different situations. Keep in mind that the sub-micron aerosols or particles will penetrate in the same way as perfume or smoke. McIlvaine comments are included in italics where the information is either misleading or questionable.

Even well-fitting N95 respirators fall slightly short of their 95% rating in real-world use, actually filtering out around 90% of incoming aerosols down to 0.3 µm. And, according to unpublished research, N95 masks that don’t have exhalation valves — which expel unfiltered exhaled air — block a similar proportion of outgoing aerosols. Much less is known about surgical and cloth masks, says Kevin Fennelly, a pulmonologist at the US National Heart, Lung, and Blood Institute in Bethesda, Maryland.

In a review of observational studies, an international research team estimates that surgical and comparable cloth masks are 67% effective in protecting the wearer. This may be true for 5 micron particles but not 5 micron droplets which become aerosolized. See the mask leakage vs particle size in the October 9 Alert.

In unpublished work, Linsey Marr, an environmental engineer at Virginia Tech in Blacksburg, and her colleagues found that even a cotton T-shirt can block half of inhaled aerosols and almost 80% of exhaled aerosols measuring 2 µm across. Once you get to aerosols of 4–5 µm, almost any fabric can block more than 80% in both directions, she says. Same answer. Initial blockage is only the first phase.

Multiple layers of fabric, she adds, are more effective, and the tighter the weave, the better. Another study found that masks with layers of different materials — such as cotton and silk — could catch aerosols more efficiently than those made from a single material.

Eric Westman, a clinical researcher at Duke University School of Medicine in Durham, North Carolina, co-authored an August study that demonstrated a method for testing mask effectiveness. His team used lasers and smartphone cameras to compare how well different cloth and surgical face coverings stopped droplets while a person spoke. “I was reassured that a lot of the masks we use did work,” he says, referring to the performance of cloth and surgical masks. But thin polyester-and-spandex neck gaiters — stretchable scarves that can be pulled up over the mouth and nose — seemed to actually reduce the size of droplets being released. “That could be worse than wearing nothing at all,” Westman says.

Some scientists advise not making too much of the finding, which was based on just one person talking. Marr and her team were among the scientists who responded with experiments of their own, finding that neck gaiters blocked most large droplets. Marr says she is writing up her results for publication.

“There’s a lot of information out there, but it’s confusing to put all the lines of evidence together,” says Angela Rasmussen, a virologist at Columbia University’s Mailman School of Public Health in New York City. “When it comes down to it, we still don’t know a lot.”

Questions about masks go beyond biology, epidemiology and physics. Human behavior is core to how well masks work in the real world. “I don’t want someone who is infected in a crowded area being confident while wearing one of these cloth coverings,” says Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota in Minneapolis.

Perhaps fortunately, some evidence suggests that donning a face mask might drive the wearer and those around them to adhere better to other measures, such as social distancing. The masks remind them of shared responsibility, perhaps. But that requires that people wear them.

Across the United States, mask use has held steady around 50% since late July. This is a substantial increase from the 20% usage seen in March and April, according to data from the Institute for Health Metrics and Evaluation at the University of Washington in Seattle (see go.nature.com/30n6kxv). The institute’s models also predicted that, as of 23 September, increasing US mask use to 95% — a level observed in Singapore and some other countries — could save nearly 100,000 lives in the period up to 1 January 2021.

“There’s a lot more we would like to know,” says Vos, who contributed to the analysis. “But given that it is such a simple, low-cost intervention with potentially such a large impact, who would not want to use it”

Further confusing the public are controversial studies and mixed messages. One study in April found masks to be ineffective but was retracted in July. Another, published in June, supported the use of masks before dozens of scientists wrote a letter attacking its methods (see go.nature.com/3jpvxpt). The authors are pushing back against calls for a retraction. Meanwhile, the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) initially refrained from recommending widespread mask usage, in part because of some hesitancy about depleting supplies for health-care workers. In April, the CDC recommended that masks be worn when physical distancing isn’t an option; the WHO followed suit in June.

There’s been a lack of consistency among political leaders, too. US President Donald Trump voiced support for masks, but rarely wore one. He even ridiculed political rival Joe Biden for consistently using a mask — just days before Trump himself tested positive for the coronavirus, on 2 October. Other world leaders, including the president and prime minister of Slovakia, Zuzana Čaputová and Igor Matovič, sported masks early in the pandemic, reportedly to set an example for their country.

Denmark was one of the last nations to mandate face masks — requiring their use on public transport from 22 August. It has maintained generally good control of the virus through early stay-at-home orders, testing and contact tracing. It is also at the forefront of COVID-19 face-mask research, in the form of two large, randomly controlled trials. A research group in Denmark enrolled some 6,000 participants, asking half to use surgical face masks when going to a workplace. Although the study is completed, Thomas Benfield, a clinical researcher at the University of Copenhagen and one of the principal investigators on the trial, says that his team is not ready to share any results.

For now, Osterholm, in Minnesota, wears a mask. Yet he laments the “lack of scientific rigor” that has so far been brought to the topic. “We criticize people all the time in the science world for making statements without any data,” he says. “We’re doing a lot of the same thing here.” The emphasis on gathering data rather than understanding the processes and creating accurate formulae seems to be a difference between the medical community and those involved with aerosol science. Droplet evaporation can be predicted and there are experts to make the calculations (see the MIilvaine interview with the UCSD droplet expert).

With in-person learning back among Deer Valley Unified School District campuses, the district this week will present on its emergency acquisition of air purifiers and filters for campus buildings in ongoing precautionary efforts against coronavirus.

Director of Finance Heather Mock will submit the request for a purchase total of $666,547.70 to procure air purifiers and filters for all district classrooms.

“Due to Covid-19 epidemic and updated recommendation from the Maricopa County Public Health Services – Ventilation in a School Setting, Districts should use portable room air purifiers with HEPA filters, especially in higher-risk areas,” the district wrote of its emergency incident. “Due to the current demand for these air purifiers, these items are scarce and have long-term delivery windows, which are extending daily.”

“Therefore, due to time constraints and availability, the district found it in the best interest to prioritize and place the purchase prior to the next scheduled governing board meeting. The purchase was procured through an approved Cooperative, due diligence was performed, and quotes were obtained.”

HEPA, or high efficiency particulate air filters, “can theoretically remove at least 99.97 percent of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns,” according to epa.gov.

The first round of a staggered return to live learning around the district came on Sept. 24. The final round will see K-8 middle school grades and high school freshmen return to their respective campuses on Wednesday, Oct. 14, at which time all district campuses will be back to full occupancy with safety guidelines in place.

New York City reopened for indoor dining at 25 percent capacity starting on September 30. There are requirements such as PPE for the service people.

Top Line Hospitality Services owner Scott Bankey has been upgrading restaurants’ HVAC units to MERV-13.

On the roof of the Michelin-starred Musket Room in Soho, Bankey installed a bit more: ultraviolet lamps designed to inactivate up to 99 percent of funguses, bacteria, and viruses in the air that’s been vented from the restaurant. The sanitized air then hits the filter, is mixed with fresh air, and is pumped back inside.

Musket Room staff were at first anxious about serving unmasked customers indoors, but owner Jennifer Vitagliano reviewed the additional modifications with them so that they could research it for themselves. “Everyone feels really confident that we’re going above and beyond to create a safe environment,” says Vitagliano, who would not confirm the exact price of the modifications but said that it cost the restaurant “a few thousand dollars.”

William Bahnfleth, professor of engineering at Penn State University, who focuses on HVAC (heating, ventilation, and air conditioning), thermal storage, and indoor air quality in his research. He weighed in on UV.

“There’s a very good track record for UV, because it’s been used in infection control since at least the 1930s,” says Bahnfleth, who also serves as the chair of the epidemic task force for ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers). “It wasn’t something that most people were aware of, but it’s been around for a long time. I’ve been doing research on it for over 20 years.”

Le Bernardin, the only three-Michelin-starred restaurant to reopen September 30 — the first day indoor dining is allowed again in NYC has installed a Needlepoint Bi-Polar Ionization system, which they say is “proven to eradicate 99.4% of airborne COVID-19 particles within 30 minutes.” The technology sounds like the stuff of science fiction: Charged particles are released into the air to hunt for dust and viruses, deactivating them upon contact. While UV lamps rely on air that’s been sucked into the HVAC unit to be sanitized, bi-polar ionization systems are, in theory, proactive. Their efficacy is still up for debate, since there have been few peer-reviewed studies on the technology.

“What ionizers definitely do is charge particles so that they stick together and they can be removed from the air more efficiently,” says Bahnfleth. “Like UV, ionizers have been around under the radar for quite a while, but they’re just something everyone’s aware of now because of the pandemic. They weren’t invented yesterday.”

The cost of these units is high, especially for restaurants that are already financially strapped as a result of the pandemic. The team at Crown Shy in the Financial District is operating at just 10 percent of their pre-pandemic revenue but spent $40,000 adding a bi-polar ionization system to the HVAC units that service both the ground-floor restaurant and its soon-to-open restaurant in the sky, Saga.

“It’s expensive, but it’s worthwhile,” says general manager and partner Jeff Katz. “Our first concern is making people feel comfortable in the space, so that they can think as little as possible about the global pandemic. Nothing ruins a meal like the thought of pathogens.”

AtmosAir, which manufactures the units that were installed in Crown Shy, has seen its revenues rocket to five to six times what it was at this point last year. “Demand is very high in New York City,” says Brian Levine, AtmosAir’s vice president of marketing.

Coronavirus preparation, like most other things, is a battle between the haves and have nots. Smaller neighborhood joints are more likely to just buy HEPA air filter units for several hundred dollars. But an organization like Union Square Hospitality Group, which operates restaurants like Gramercy Tavern, Blue Smoke, and Union Square Cafe, can afford to leave no box unchecked, spending tens of thousands of dollars to beef up its filtration systems, adding both a UV light rig and bi-polar ionizer at each of its locations.

While these extra precautions may be helpful to ease the minds of a shell-shocked population, the state reopening guidelines also recommends simple things like a basic ventilation system or even leaving all the doors and windows open. Restaurants in the Northeast and the rest of New York State have been open for indoor dining for months without a surge in coronavirus cases, despite many places lacking the resources to install high-end HVAC systems.

In recent interviews, the nation’s leading infectious disease expert, Dr. Anthony Fauci, stated that dining indoors “absolutely increases the risk,” but stressed the importance of harm reduction in dealing with COVID-19. “There comes a point where you’ve got to accept human nature,” Fauci said of people’s desire to socialize. He added that in addition to a low local positivity rate, “anything that has airflow out, not airflow in the room” was the key to making restaurants safer.

“There’s a lot of evidence that good ventilation is protective,” says Bahnfleth. “And when you add filters to it and air cleaners, things get even better.”

Meat Packers Need Efficient Masks and Fan Filter Units

There is an extensive analysis of the meat packing industry attempts to protect workers in Mother Jones by Tom Philpott. He is the food and ag correspondent for Mother Jones. He can be reached at tphilpott@motherjones.com, or on Twitter at @tomphilpott.

We are showing the Philpott analysis with our comments in italics. The coronavirus has fallen heavily on the people who cut and pack the US meat supply. After blitzing meatpacking plants all spring and summer, the illness has infected at least 43,100 of these workers and killed 206, according to the running tally kept by the Food and Environment Reporting Network’s Leah Douglas. Lately, new cases and deaths within the industry have been leveling off, according to Douglas’ data. And media attention has shifted from the deadly toll on workers to the gentle penalties the Trump administration has imposed on the massive companies that dominate the meat industry for their worker-safety performance during the crisis.

Though it’s failed to garner much national attention, the deadliest meatpacking outbreak of all has unfolded in recent weeks in California’s agriculture-dominated San Joaquin Valley. On September 1, West Coast poultry powerhouse Foster Farms closed its Livingston, California, chicken plant by order of the Merced County Department of Public Health, after acknowledging 392 positive COVID-19 tests and eight deaths among employees. After another plant employee who had been hospitalized with COVID since August died in mid-September, the outbreak’s death toll now stands at nine, the most COVID-related fatalities of any single meatpacking plant, according to FERN’s Douglas.

Could the company have done more to prevent the outbreak? The Merced County health department repeatedly warned Foster Farms to ramp up efforts to protect its employees, before any deaths occurred. In an August 27 press release, the health department reported that it had been unsuccessfully urging Foster Farms to take precautionary safety measures since late June, a “month prior” to any COVID-related deaths.

On June 29, as COVID cases at the plant “continued to rise,” county health officials inspected the plant. To limit the outbreak, the health department suggested “significant changes to the employee break spaces and performing widespread testing of employees within the facility.” The department continued to call for a testing ramp-up throughout the month of July, but by the final days of the month, Foster Farms had “tested less than 10 percent of the department with the largest [COVID] impact within the facility,” the report states. Among the employees who were tested, more than 25 percent turned up positive.

In August, the department stepped up its campaign to push Foster Farms to increase testing and tweak common areas. On August 3, officials made a second visit to the Foster plant—this time accompanied by representatives of Cal/OSHA, the state’s worker-safety enforcement agency. On August 5 and 11, the department repeated its call on the company to increase employee testing and tweak common areas to enable social distancing. Meanwhile, the coronavirus continued to spread through the complex, “posing a significant threat to Foster Farms employees and the surrounding community,” the health department report states. Finally, on August 27, two months after its initial call for common-area changes and widespread testing, the health department ordered the plant to close, pending universal employee testing and “significant changes” to all break spaces and “areas of potential congregation” to “ensure adequate social distancing of all workers on the plant.” In the period of time between the initial June 29 recommendations and the August 27 close order, eight workers died of COVID-19.

The company failed to keep workers informed about the outbreak as it spread through the plant over the summer, says Erika Navarrete of the United Farm Workers of America, which represents the plant’s workers. Workers have told Navarrete that Foster Farms has only given them two masks per person total since the start of the pandemic, so they’ve had to buy this crucial protection themselves. And while the company has installed plexiglass barriers between stations on the facility floor, “workers are still too close together,” working shoulder-shoulder on the line, says Navarrete, who has visited the plant several times. A Foster Farms spokesperson declined to comment.

The conditions described by Navarrete—masked workers toiling close together, separated by plastic barriers—appear to be standard poultry-industry practice during the COVID crisis. In an article entitled “Our #1 Priority: Keeping Chicken Company Employees Safe & Healthy During COVID-19,” the National Chicken Council—a trade group representing US chicken processors—includes the below photograph of workers on a chicken-production during the pandemic. A National Chicken Council spokesperson alerted that meat giant Tyson Foods had posted the photo on a web gallery available to media showing the “protective measures” the company is taking in response to COVID-19.

Is the arrangement sufficient to protect workers from COVID? Federal worker-safety authorities are fuzzy on the topic. The US Occupational Safety and Health Administration has declined to issue binding workplace regulations to impede the spread of COVID. Along with the Centers for Disease Control and Prevention, OSHA released voluntary meatpacking-industry guidelines on July 26. The guidelines call on companies to “modify the alignment of workstations, including along processing lines, if feasible, so that workers are at least six feet apart in all directions (e.g., side-to-side and when facing one another), when possible.” They also suggest “physical barriers, such as strip curtains, plexiglass or similar materials…to separate meat and poultry processing workers from each other.” The guidelines don’t comment on whether barriers negate the need for social distancing.

Two independent occupational health experts Philpott consulted say distancing is essential, with or without barriers in place. “Medical masks and plastic sheeting are not enough,” said David Michaels, who served as chief of the Occupational Safety and Health Administration under President Barack Obama and is now a professor of environmental and occupational health at George Washington University. He pointed to a July 2020 investigation by German scientists of a COVID-19 outbreak in a German meatpacking plant which found that “climate conditions and airflow” in these plants can “can promote efficient spread” of the virus at “distances of more than 8 meters,” or 26 feet. “Workers in poultry plants need greater distance between them, and they need respirators, not medical masks,” Michaels said.

The important point here is that you need respirators not masks. Furthermore these respirators have to be tight fitting. Look at this picture and envision that many of the workers are smoking cigarettes. How effective would the partitions or loose fitting masks be?

Plastic barriers are “more effective in a grocery store situation where you’re having very quick interactions with people,” said Marissa Baker, director of the Industrial Hygiene Training program at the University of Washington’s Department of Environmental & Occupational Health Sciences. But in meatpacking plants, “you’re standing shoulder to shoulder with someone for eight hours a day—unless you’re in your own separate box, there’s definitely a chance for virus to get around those barriers.” She said a safer approach would be to keep the barriers but spread workers at least six feet apart—which would likely require the company to slow down its production. A slower line would also protect workers from COVID-19 in another way, Baker added: “When you have people working fast, people are breathing harder—and that leads to more particle generation,” and thus more potential exposure to pathogens.

You could keep the close spacing if you have fan filter units spaced along the line. The downward clean air flow will keep the virus from moving horizontally.

“Medical masks and plastic sheeting are not enough,” according to occupational safety expert David Michaels.

When the COVID crisis took root in the spring, Foster Farms joined several other meatpacking companies in delivering its workers a salary bonus of $1 per hour for working shoulder-to-shoulder during a pandemic. But the company ended the bonus on May 31—just before the disease began to spread through the plant, Navarrete said. UFW is currently negotiating with Foster Farms on a contract for the plant’s workers, she added, and is demanding $2 per hour hazard pay for the duration of the pandemic.

It remains to be seen whether Foster Farms will face penalties for its management of the Livingston outbreak. So far, despite widespread contagion and fatalities in plants across the country, Trump’s OSHA has doled out two fines—at levels that Michaels, the former OSHA administrator, has called “less than a slap on the wrist.” Trump’s OSHA recently hit pork giant Smithfield with a $13,494 fine for an April outbreak that infected at least 1,294 workers and killed 4 at its massive pork operation in Sioux Falls, South Dakota; and it laid a $15,615 penalty on meatpacking behemoth JBS for an outbreak that led to 300 positive tests and six worker deaths at its Greeley, Colorado, beef plant.

In California, worker-safety laws are enforced by a state agency called Cal/OSHA, a division of the California Department of Industrial Relations. On September 9, Cal/OSHA hit mid-sized frozen-foods manufacturer, Overhill Farms, with a $200,000 fine, and levied another $200,000 one on the temporary-employment agency it uses, Jobsource North America. Their infraction, according to the press release: They failed to take measures to protect workers from COVID-19, resulting in “more than 20 illnesses and, in the case of Overhill Farms, one death.”

On September 8, Foster Farms reopened its Livingston plant after complying with health department conditions. Whether it will pay a price for the outbreak remains to be seen. In an email, a spokesman for the California Department of Industrial Relations wrote: “Cal/OSHA opened an inspection on July 23 at the Foster Farms in Livingston after notification that a worker died from complications related to a COVID-19 infection.” He declined to comment further on what he called an “ongoing inspection” of the plant, but added that “by law, Cal/OSHA has up to six months from the opening date of an inspection to issue citations.” In the meantime, dozens of workers in the plant continue to work shoulder to shoulder as the pandemic grinds on.