In the fight against coronavirus disease (COVID-19) caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), one of the weapons humans use to prevent infection is wearing a face mask. I will. Many countries do not require this infection control measure, but it does help protect against inhalation of virus-laden droplets and aerosols.
New research published in the journal Biophysics Journal Face masks increase the humidity in the air inhaled by mask wearers, according to researchers at the National Institute of Diabetes, Gastroenterology and Kidney Disease (NIDDK), which is part of the National Institutes of Health (NIH). it was done. Moisture levels in inhaled air may be associated with reduced levels of COVID-19 severity.
Humidity and respiratory illness
The seasonality of respiratory illness is associated with low absolute outdoor humidity and low relative indoor humidity. During these times, the evaporation of water in the mucosal lining of the airways increases.
Airway hydration is known to benefit the immune system. High levels of humidity can reduce the spread of the virus into the lungs. It promotes mucus fimbria clearance (MCC), a protective mechanism that removes mucus and particles from the lungs.
Apart from this, high humidity strengthens the immune system and produces a special protein called interferon. These fight the virus by a mechanism called the interferon response, which may explain why people are more common to get respiratory infections in the winter and cold seasons.
Humidity of face mask
Researchers have demonstrated that when mask fibers absorb normal respiration, an absorption-desorption cycle occurs within the face mask, resulting in hypersaturated air in the exhaled air and evaporation during inhalation of dry environment air.
Researchers have tested four common types of masks: N95 masks, 3-layer surgical masks, 2-layer cotton polyester masks, and thick cotton masks. They asked volunteers to exhale into a sealed steel box to measure humidity levels.
The team made measurements at three temperatures from 46 ° F to 98 ° F. They found that when volunteers wore masks, the accumulation of moisture in the boxes was significantly reduced. In addition, all four masks tested increased the humidity level of the intake air to varying degrees.
For a double layer cotton mask with a significant heat capacity, the intake air temperature will be higher than room temperature. An effective increase in relative humidity can exceed 100%.
“We propose that the recently reported disease-relieving effect of generic face masks is dominated by a strong increase in inspiratory humidity, both before and after an upper respiratory tract infection occurs. , Promotes the mucilage hair clearance of the pathogen from the lungs, “the researchers wrote in the paper.
Successful mucous fimbria clearance can delay and reduce infection of the lower respiratory tract and limit the severity of the disease. The mask acts as a protection against respiratory droplets while reducing the risk of infection by increasing humidity levels.
“Face masks have been found to significantly increase the humidity of inspiratory air, and the resulting airway hydration is responsible for the documented findings that link the reduction in severity of COVID-19 infections to wearing masks. I suggest there is a possibility, “said the NIH Distinguished Investigator.
“High levels of humidity have been shown to reduce the severity of influenza and may be applied to the severity of COVID-19 through a similar mechanism,” he added.
Moreover, elevated humidity levels are experienced by most people wearing masks unaware that they can reduce the risk of infection.
“This mechanism of action suggests that masks can benefit the wearer even after an upper respiratory tract infection has occurred, and the conventional masks that limit the transmission of the disease from person to person. It complements function. This potential therapeutic use should be further studied, “the researchers concluded in the study.
Wearing a face mask is part of a global campaign to comply with infection control measures. Preventing infection while the vaccine is being deployed may depend on protecting yourself from SARS-CoV-2 carriers. In addition to wearing a mask, regular hand hygiene and physical distance can reduce the risk of infection.