Sunday, September 26, 2021

Evidence shows that, yes, masks prevent COVID-19 – and surgical masks are the way to go

Laura (Layla) H. Kwong September 22, 2021 8.55am EDT

Do masks work? And if so, should you reach for an N95, a surgical mask, a cloth mask or a gaiter?

Over the past year and a half, researchers have produced a lot of laboratory, model-based and observational evidence on the effectiveness of masks. For many people it has understandably been hard to keep track of what works and what doesn’t.

I’m an assistant professor of environmental health sciences. I, too, have wondered about the answers to these questions, and earlier this year I led a study that examined the research about which materials are best.

Recently, I was part of the largest randomized controlled trial to date testing the effectiveness of mask-wearing. The study has yet to be peer-reviewed but has been well received by the medical community. What we found provides gold-standard evidence that confirms previous research: Wearing masks, particularly surgical masks, prevents COVID-19. Laboratory studies help scientists understand the physics of masks and spread.
Lab and observational studies

People have been using masks to protect themselves from contracting diseases since the Manchurian outbreak of plague in 1910.

During the coronavirus pandemic, the focus has been on masks as a way of preventing infected persons from contaminating the air around them – called source control. Recent laboratory evidence supports this idea. In April 2020, researchers showed that people infected with a coronavirus – but not SARS-CoV-2 – exhaled less coronavirus RNA into the air around them if they wore a mask. A number of additional laboratory studies have also supported the efficacy of masks.

Out in the real world, many epidemiologists have examined the impact of masking and mask policies to see if masks help slow the spread of COVID-19. One observational study – meaning it was not a controlled study with people wearing or not wearing masks – published in late 2020 looked at demographics, testing, lockdowns and mask-wearing in 196 countries. The researchers found that after controlling for other factors, countries with cultural norms or policies that supported mask-wearing saw weekly per capita coronavirus mortality increase 16% during outbreaks, compared with a 62% weekly increase in countries without mask-wearing norms

Researchers gave surgical masks to adults in 200 villages in Bangladesh to test whether they reduce COVID-19. Innovations for Poverty Action, CC BY-ND
Large-scale randomized mask-wearing

Laboratory, observational and modeling studies, have consistently supported the value of many types of masks. But these approaches are not as strong as large-scale randomized controlled trials among the general public, which compare groups after the intervention has been implemented in some randomly selected groups and not implemented in comparison groups. One such study done in Denmark in early 2020 was inconclusive, but it was relatively small and relied on participants to self-report mask-wearing.

Watch this Youtube Comparision with four different scenarios; 
Four scenarios

From November 2020 to April 2021, my colleagues Jason Abaluck, Ahmed Mushfiq Mobarak, Stephen P. Luby, Ashley Styczynski and I – in close collaboration with partners in the Bangladeshi government and the research nonprofit Innovations for Poverty Action – conducted a large-scale randomized controlled trial on masking in Bangladesh. Our goals were to learn the best ways to increase mask-wearing without a mandate, understand the effect of mask-wearing on COVID-19, and compare cloth masks and surgical masks.

The study involved 341,126 adults in 600 villages in rural Bangladesh. In 300 villages we did not promote masks, and people continued wearing masks, or not, as they had before. In 200 villages we promoted the use of surgical masks, and in 100 villages we promoted cloth masks, testing a number of different outreach strategies in each group.

Over the course of eight weeks, our team distributed free masks to each adult in the mask groups at their homes, provided information about the risks of COVID-19 and the value of mask-wearing. We also worked with community and religious leaders to model and promote mask-wearing and hired staff to walk around the village and politely ask people who were not wearing a mask to put one on. Plainclothes staff recorded whether people wore masks properly over their mouth and nose, improperly or not at all.

Both five weeks and nine weeks after starting the study, we collected data from all adults on symptoms of COVID-19 during the study period. If a person reported any symptoms of COVID-19, we took and tested a blood sample for evidence of infection.
Based on current evidence, many places across the U.S. have some form of mask requirements. AP Photo/LM Otero
Mask-wearing reduced COVID-19

The first question my colleagues and I needed to answer was whether our efforts led to increased mask-wearing. Mask usage more than tripled, from 13% in the group that wasn’t given masks to 42% in the group that was. Interestingly, physical distancing also increased by 5% in the villages where we promoted masks.

In the 300 villages where we distributed any type of mask, we saw a 9% reduction in COVID-19 compared with villages where we did not promote masks. Because of the small number of villages where we promoted cloth masks, we were not able to tell whether cloth or surgical masks were better at reducing COVID-19.

We did have a large enough sample size to determine that in villages where we distributed surgical masks, COVID-19 fell by 12%. In those villages COVID-19 fell by 35% for people 60 years and older and 23% for people 50-60 years old. When looking at COVID-19-like symptoms we found that both surgical and cloth masks resulted in a 12% reduction.
The body of evidence supports masks

Before this study there was a lack of gold-standard evidence on the effectiveness of masks to reduce COVID-19 in daily life. Our study provides strong real-world evidence that surgical masks reduce COVID-19, particularly for older adults who face higher rates of death and disability if they get infected.

Policymakers and public health officials now have evidence from laboratories, models, observations and real-world trials that support mask-wearing to reduce respiratory diseases, including COVID-19. Given that COVID-19 can so easily spread from person to person, if more people wear masks the benefits increase.

So next time you are wondering if you should wear a mask, the answer is yes. Cloth masks are likely better than nothing, but high-quality surgical masks or masks with even higher filtration efficiency and better fit – such as KF94s, KN95s and N95s – are the most effective at preventing COVID-19.

Tuesday, September 14, 2021

Time to instill integrity into vaccination verification


By Howard L. Smith, Ph.D.; David N. Gans, MSHA, FACMPE; Zung Vu Tran, Ph.D., FACSM, FSS; Nina Nichols; Brett Goldman; Ryan Hawkos; and Neill F. Piland, Dr.PH.

Even before COVID-19 vaccinations began to be widely disseminated, concerns were expressed about which agencies would document and monitor them. Just as quickly, the federal government took the position that it was not going to institute a system of passports. Those who were inoculated would receive a CDC vaccination card and that was the end of discussion at that time. Well, not quite. Wishful thinking on the part of our government to avoid vaccination documentation and verification has created a formidable crisis about the integrity of vaccinations at a pivotal juncture. 

Vaccinated and unvaccinated alike want to return to some semblance of normalcy that reflects any of the millions of ways that people work, play, pray or interact. This has become possible due to widespread immunization of the U.S. population coupled with prudent social distancing and mask use, which momentarily dampened COVID-19 case counts until variants proliferated. However, as long as a sizeable number of people avoid vaccination, the virus will find ways to thrive.

Increasingly, businesses, bars and restaurants, entertainment venues, sporting events, colleges, state and municipal governments, the Veterans Administration and federal agencies require proof of vaccination or continual tests. This has nurtured fertile ground for counterfeit cards. Anti-vaxers do not want to be prevented from partaking in such activities; plus, many people simply enjoy beating the system or proving that no one can make them do what they do not want to do regardless of the expense to their health or society. This self-centeredness is costing the United States some $2.3 billion in hospitalization for unvaccinated people during June and July 2021 alone.1

As we struggle to reopen our society and rejuvenate our economy, the long-ignored challenge of instilling integrity into vaccination documentation must be overcome. But does anyone really trust that the person sitting, standing or otherwise in their personal space has actually been vaccinated as they espouse or claim with a little sheet of paper? Remember, it only takes one exposure to acquire a virus that might kill you.

The preceding thoughts clearly underscore that it is past time for a viable and efficient vaccination verification system. Such a system would function much like the Good Housekeeping Seal of Approval or OSHA’s “Nationally Recognized Testing Laboratories,” in which valid third-party organizations with appropriate qualifications perform safety testing and certification of products. The CDC, or other health-related agency, could oversee a national vaccination verification system. For example, sources approved by the CDC (e.g., Nationally Recognized Verification Entities) could create highly recognizable electronic passports that substantiate COVID-19 vaccination. The technology and products already exist as private firms have looked ahead to now — when vaccination certification would be paramount to a functioning society.

Currently, the lack of a secure verification system is facilitating fraud as people falsify credentials, forge vaccination cards or hack digital certification tools to meet entry requirements for health facilities, mass gatherings and places of business. Physical and digital health records such as the CDC card and IBM’s Excelsior pass have been easily falsified.2

Cell phone-enabled vaccination verification should be an immediate reality. The world relies on cell phones to do most anything and everything. Verification needs to be easy to use at point of entry (e.g., into a restaurant, bar or entertainment venue), inexpensive, and widely recognized as one of the CDC-approved “Good Health Keeping Passports of Vaccination.” This will facilitate disease prevention, efficient use of health services and facilities and reduce healthcare costs, as well as invigorate economic activity and development.

It is time to quit stalling. All along we have known that there would be a need for bulletproof verification of vaccination to re-boot societal functioning. Let’s invest a modicum of resources in a reliable vaccine verification/certification system of high integrity as we have in developing the vaccines and confidently move onward and upward.

Sunday, September 12, 2021

The Physiology of Treading Water Efficiently

OUTSIDE magazine
Alex Hutchinson
Sep 9, 2021

A new study measures the physical and cognitive load of four different treading techniques. 
The key? Generate lift.  

On a canoe trip down the Spanish River in northern Ontario last month, my friends and I kept noticing an unusually high concentration of really, really big leeches lurking at the shores of our campsites. As a result, our pre-dinner swims involved paddling our canoes out to deep water then jumping in from there. 

This gave me lots of time to think about treading water: how long I’d be able to keep it up if necessary, if I was doing it properly, and whether that even mattered. Imagine my surprise, then, when I got home and saw this paper, just published in Frontiers in Physiology by Tina van Duijn of the University of Otago and her colleagues: “A Multidisciplinary Comparison of Different Techniques Among Skilled Water Treaders.” 

They put 21 volunteers, all experienced water polo players, synchronized swimmers, or competitive swimmers who self-identified as water-treading experts, through a series of physiological and cognitive tests while performing four different styles of treading. 

The verdict: some techniques really are substantially better than others. The four techniques are as follows: 

Running in the water: This one is pretty self-explanatory. Hands and feet are moving up and down in a running-like motion. 

Flutter kick: Your hands are sculling back and forth along the surface of the water, while your legs do a flutter kick. 

Upright breaststroke: Your hands are still sculling along the surface of the water, but your legs are doing the distinctive frog kick of the breaststroke. 

Eggbeater: It’s similar to the upright breaststroke, with the key difference that your legs are kicking one at a time instead of synchronously, producing an eggbeater pattern of alternating circles with each leg. 

Like pretty much everyone who took swimming lessons as a kid, I was taught the eggbeater. But as I floated down the Spanish, I realized that over the years I’ve settled into a comfortable upright breaststroke style as a default. In fact, I wasn’t really sure how to do the eggbeater anymore—which, as I thought back to an article I wrote a few years ago called “How to Survive 75 Hours Alone in the Ocean,” vaguely worried me. 

Was I working way harder than I needed to in order to stay afloat? It turns out I’m not alone in my habits. Among the expert water treaders in the study, 71 percent of them opted for eggbeater in their warm-up, but 14 percent each chose upright breaststroke and flutter kick. There were clear differences in how efficient the different techniques were, with running and flutter kick performing equally poorly, and upright breaststroke and eggbeater performing equally well. This pattern showed up in every outcome measure. 

For example, here’s the oxygen consumption (VO2) during the last portion of 3.5-minute test bouts, measured through a breathing mask attached to a snorkel: (Photo: Frontiers in Physiology) Oxygen consumption is roughly proportional to energy consumption, so the lower values for breaststroke and eggbeater mean they’re more efficient than the other two strokes. Aside: these values are adjusted based on the “wet weight” of each participant, which was measured by weighing them underwater. 

Normally VO2 measurements are adjusted for weight, since heavier people burn more energy—but in this case, wet weight was used to also account for differences in buoyancy. 

As a guy who sinks like a stone in water, I found this interesting! Similarly, heart rate was higher in running (140 beats per minute, on average) and flutter kick (147) than in breaststroke (129) and eggbeater (129). 

Same for perceived effort: 14 and 13 on the Borg scale from 6 to 20, versus 11 and 11, respectively. For cognitive load, they used the NASA-Task Load Index, which assesses things like effort, frustration, and perceived performance, and they tested reaction time in response to visual and audible signals. In both cases, breaststroke and eggbeater produced better results than the other two. 

There’s some interesting physics in the stroke comparisons. The two inferior techniques largely rely on pushing down against the water to move the body upward. This has two problems: water is too thin to provide much support, and even when the pushing works you get a lot of wasted up-and-down motion. The two better strokes, in contrast, involve lateral movements of the arms and legs: your cupped hand acts like an airplane wing or sailboat sail, generating lift forces perpendicular to the plane of motion. This is more efficient than pushing on the water, and produces less wasted vertical bobbing. 

 There’s one key difference between upright breaststroke and the eggbeater: in the former, your legs are kicking outward at the same time, while in the latter they’re alternating. This means that breaststroke produces some of that undesired up (when you kick) and down (between kicks) motion—and that effect is exacerbated if you stop sculling with your hands. 

In the eggbeater, there’s always one leg moving, so you get a smoother, more continuous lift that can keep you up even without your hands. The study didn’t test anything that required using your arms—but if you want to throw a water polo ball, strike a fancy pose during your synchro routine, or signal frantically to a passing ship that you need rescue, eggbeater looks like a much better bet. Next time I’m in deep water, I’m going to see if I can get the hang of it again.

Wednesday, September 8, 2021

Surprising ways you may be getting sun-damaged skin (From Kaiser-Permanente)

Make coffee. Eat breakfast. Brush your teeth. Take a shower.

This typical morning routine is missing an important step: Put on sunscreen.

Why should you wear it every day? Because sun-damaged skin may be sneaking up on you.

You know you and your family should wear sunscreen before spending a long afternoon outdoors, but sun damage is cumulative — short periods of unprotected sun exposure add up over time, eventually leading to visible damage to your skin and a higher risk of skin cancer.
What is sun damage?

Sun damage, or photoaging, is when ultraviolet (UV) light from the sun prematurely ages your skin. There are 2 kinds of UV light — UVA and UVB. UVA light damages skin at all levels, from the surface to the deepest layer, breaking down collagen and elastin fibers. UVB light damages the outer layer of skin and your DNA, which can lead to cancer. A simplified way to remember the difference is that UVA rays are aging and UVB rays are burning. If you have darker skin, it’s less likely to burn — but it can still be damaged by UVA rays.

Signs of sun-damaged skin include:
• Broken capillaries, usually around the nose
• Loss of skin elasticity
• Pigmentation changes, such as age spots and brown patches of discoloration (known as melasma)
• Red blotches
• Uneven skin texture
• Wrinkles

For a safer, healthier summer glow, try sunless tanning.

Surprising Ways you may be getting sun damage

Direct sun exposure occurs anytime you’re outdoors unprotected. Indirect sun exposure is when something is partially protecting you from the sun, like a window. If you’re not wearing adequate sunscreen, these exposures add up and lead to lasting sun damage.

“People are running errands — 5 minutes here, 10 minutes there — or walking their dog, and they’re not taking into consideration the cumulative, short bursts that they’re getting,” says Sarah Adams, MD, a dermatologist at Kaiser Permanente Southern California. “All of the sudden, they’ve been outside for an hour and a half and they haven’t worn any sunscreen or any sun protection.”

Some examples of surprising sun exposure include:
• Short trips outdoors, like walking from a parking lot to a building
• Being under shade, like an umbrella
• Clouds covering the sun
• Sitting next to a window — including in your home office, working at a drive-thru, or traveling in a car, bus, or airplane

And yes, you read that last one right — you should even wear sunscreen when you’re home all day if you’re near a window. Windows usually block UVB rays, but not UVA rays.

“When I see patients in clinic, I notice more photoaging — more dark marks, more pigmentation — often affecting the left side of their face,” Dr. Adams says. “I can often tell that someone was a driver versus a passenger because of the amount of sun damage that there is on one side of their face versus the other.”

Your skin can also become more sensitive to the sun if you’re on certain medications or skin products — so take extra care to protect yourself. Read the labels or check with your doctor if you’re using:
Acne medications like Accutane
Antibiotics, particularly tetracyclines
Some birth control pills
Some heart medications for arrhythmia
Topical skin products such as retinols, glycolic acid, and other alpha hydroxy acids
How to protect your skin from sun damage

Use sunscreen with SPF 30 or higher on yourself and your kids every day to prevent sun damage. Look for a broad-spectrum formula, which protects from both UVA and UVB light. Encourage your teens and older kids to use it daily, too.

Besides your face, be sure to apply sunscreen to commonly overlooked areas, such as your ears, the sides and back of your neck, the V of your chest, and the backs of your hands.

Get fast, easy coverage by wearing long-sleeved shirts and pants, a wide-brimmed hat, and sunglasses. Invest in clothes with UPF (ultraviolet protection factor) for extra protection.

Limit how much time you and your family spend outdoors between 10 a.m. and 2 p.m. when the sun’s rays are strongest. But remember, UV rays can be a concern anytime the sun is up. Use your smartphone’s weather app to check the current UV index — if it’s 3 or higher, you should protect your skin.

Some good news — you don’t need to reapply sunscreen throughout the day if you’re not sweating or swimming. Just make it part of your daily morning routine.