A new study published by Cell Press suggests prolonged mask-wearing may increase the risk of testicular toxicity, stillbirths, and cognitive decline.
The group of German researchers who carried out the meta-analysis study, which looked at dozens of papers, theorized that prolonged mask-wearing creates a toxic buildup of carbon dioxide in the "dead space" pocket of the mask, leading to a host of metabolic issues.
The study found that pregnant rats exposed to 3% carbon dioxide, equivalent to 0.8% for humans, experienced stillbirths and birth defects.
The study also found that male mice exposed to 2.5% carbon dioxide for four hours, equal to 0.5% for humans, experienced the destruction of testicular cells and sperm. Another study found that extended carbon dioxide exposure to both pregnant rats and young mice led to "neuron destruction ... increased anxiety and impaired memory and learning of the offspring after birth."
The researchers noted that '"circumstantial evidence" exists linking mask use to a significant rise in stillbirths worldwide. However, the study could not conclusively prove that masks were directly responsible for any of these complications.
The Daily Mail reported that Dr. Stuart Fischer, an emergency care physician in New York, was among those who question whether there is a "toxic buildup" of carbon dioxide caused by mask-wearing.
"I wouldn't say this happens, because the body adjusts the pH, the acid/base balance very quickly. Respiratory acidosis due to face masks is unlikely, although short-term side effects might affect people with chronic lung disease," Fischer said.
But Kevin Bass, a cell and molecular biology doctoral student, tweeted that the new paper was "explosive."
Further along in the thread, he tweeted: "However, we do not have any good evidence in pregnant women ... of the long-term effects of mask-wearing and therefore no evidence that these effects occur in women.
"All we have are animal studies and a clear indication that changes in CO2 concentrations do occur in mask-wearing women," he continued.
During the height of the pandemic, one way mask mandates in the United States were enforced was with an up to $3,000 fine for people who repeatedly flew on airplanes unmasked. Initially, Dr. Anthony Fauci advised people not to wear masks before later recommending that everyone wear a mask.