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Masks offer 'small' benefit against COVID, increased CO2 may be tied to stillbirths: research

CO2 concentration after 5 minutes jumps higher than U.S. Navy "exposure limits for submarines carrying a female crew," German researchers find. 12-hour D.C. bar exam may dump mask rule after memo leak.

Published: May 29, 2023 11:09pm

The termination of the COVID-19 national emergency has not ended mask mandates in various jurisdictions and settings such as healthcare, even as more peer-reviewed research suggests that face coverings can cause more harm than good.

The Annals of Internal Medicine published the "final update" to a three-year "living, rapid review" of research on mask effectiveness against COVID infection, which concluded masks in healthcare and community settings "may be associated with a small reduction in risk" — 10-18% — but that the evidence is weak.

That echoes the recent assertion of former White House COVID advisor Anthony Fauci, who led the National Institute of Allergy and Infectious Diseases for 38 years. A forceful proponent of masking, he nonetheless told The New York Times Magazine last month that "masks work at the margins — maybe 10 percent."

The Oregon Health and Science University researchers reviewed three randomized controlled trials (RCTs) and 21 observational studies. Reductions were "nonstatistically significant" in a Danish RCT and Canadian case-control study and statistically significant in a small Brazil study. 

"The evidence for mask use versus nonuse and more versus less consistent mask use remained insufficient," they concluded. Both observational studies and RCTs had "imprecision" and methodological limitations.

A much longer ongoing review of mask effectiveness against viral transmission, both COVID and influenza, found masks "probably make little to no difference" based on RCTs, the most rigorous form of scientific evidence.

A "scoping review" based on a "systematic literature search" of carbon-dioxide exposure and mask use, published in the Cell Press journal Heliyon, found that wearing a mask for more than 5 minutes can increase CO2 exposure to 1.41% to 3.2% of inhaled air, far above the 0.04% concentration in fresh air.

"US Navy toxicity experts set the exposure limits for submarines carrying a female crew to 0.8% CO2 based on animal studies which indicated an increased risk for stillbirths," the German researchers wrote, while mammals "chronically exposed" to 0.3% CO2 show "irreversible neuron damage in the offspring, reduced spatial learning" and "reduced circulating levels of the insulin-like growth factor-1." 

Data also show "testicular toxicity in adolescents" in concentrations over 0.5%, they said.

"Circumstantial evidence exists that extended mask use may be related to current observations of stillbirths and to reduced verbal motor and overall cognitive performance in children born during the pandemic."

The findings are in line with an Italian mask study published in Environmental Health Insights last fall that found 5 minutes of CO2 buildup "approached the highest acceptable exposure threshold recommended for workers" under U.S. and European labor law, and "concerningly high concentrations" in minors and "virtually" everyone wearing high-quality respirators.

New York City's municipal health system recently reiterated it is still requiring masks for everyone 2 and older "regardless of vaccination status," and activists are pressuring a local hospital to reinstate its mandate by projecting slogans on the building.

The D.C. Court of Appeals, which administers the bar exam for the District, entered damage control after the Washington Free Beacon published its May 18 memo to test-takers requiring masks for the 12-hour exam scheduled for this summer. D.C. courts removed their own building mask rule in April.

Public relations director Douglas Buchanan told the Free Beacon May 19 that the "protocols may change between now and the time of the exam." But he also accidentally included an email from acting chief deputy clerk Marie Robertson, who received the initial query, that groused a test-taker tried to "force our hand" by leaking the memo.

"We are likely to lift the mask requirement, but I’d like to announce that closer to the exam and I prefer that we announce it, and not that it comes from the media," Robertson told Buchanan. "I hope test-takers sue the D.C. Bar," prominent D.C. legal scholar Ilya Shapiro told the Washington Examiner, calling the requirement "insane" and "cruel." 

Buchanan didn't answer Just the News queries on whether it had yet made a decision on masks for the exam a week later.

A Las Vegas-based company that provides Grand Canyon tours is still informing customers the "mandatory mask policy has been re-instated" inside buildings and shuttle buses at the South Rim, which drew notice on Twitter last week. .

A customer service agent told Just the News the website is out of date and there's no live mandate. The message about the mandate was added to the website between Aug. 14 and Sept. 20, according to archives.