Possible toxicity of chronic carbon dioxide exposure associated with face mask use, particularly in pregnant women, children and adolescents - A scoping review.

Introduction: During the SARS-CoV-2-pandemic, face masks have become one of the most important ubiquitous factors affecting human breathing. It increases the resistance and dead space volume leading to a re-breathing of CO2. So far, this phenomenon and possible implications on early life has not been evaluated in depth. Method: As part of a scoping review, literature was systematically reviewed regarding CO2 exposure and facemask use. Results: Fresh air has around 0.04% CO2, while wearing masks more than 5 min bears a possible chronic exposure to carbon dioxide of 1.41% to 3.2% of the inhaled air. Although the buildup is usually within the short-term exposure limits, long-term exceedances and consequences must be considered due to experimental data. 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. Additionally, mammals who were chronically exposed to 0.3% CO2 the experimental data demonstrate a teratogenicity with irreversible neuron damage in the offspring, reduced spatial learning caused by brainstem neuron apoptosis and reduced circulating levels of the insulin-like growth factor-1. With significant impact on three readout parameters (morphological, functional, marker) this chronic 0.3% CO2 exposure has to be defined as being toxic. Additional data exists on the exposure of chronic 0.3% CO2 in adolescent mammals causing neuron destruction, which includes less activity, increased anxiety and impaired learning and memory. There is also data indicating testicular toxicity in adolescents at CO2 inhalation concentrations above 0.5%. Discussion: There is a possible negative impact risk by imposing extended mask mandates especially for vulnerable subgroups. 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. A need exists to reconsider mask mandates.

Does Prolonged Use of N95 Masks Affect Nasal Mucociliary Clearance? A Single Group Pre-Post Study.

OBJECTIVE: It has been shown that prolonged use of face masks results in physiological changes in the nasal cavity. The objective of this study was to examine the effect of prolonged use of face masks on nasal mucociliary clearance (NMC). METHODS: A single group pre-post study was conducted to determine the effects of prolonged use of N95 face mask (≥4 hours) on the NMC rates in health care workers. Saccharin transit time (STT) was used to measure the NMC. STT before and after using an N95 mask for at least 4 hours was measured for all participants in controlled conditions of temperature and humidity. RESULTS: Forty-eight volunteers (20 female and 28 male) completed the study after the enrollment of 57 volunteers. The mean STT before mask use was 580.27 ± 193.93 seconds (95% CI; 523.95-636.58 seconds) and after mask use was 667.47 ± 237.42 seconds (95% CI; 598.53-736.42 seconds). There was significant prolongation of the NMC after prolonged use of N95 mask on performing the paired t-test (P = .002). The mean prolongation was 87.20 ± 184.97 seconds with an actual effect size of 0.40. Ambient temperature and humidity were not significantly different at the two test instances. CONCLUSION: Use of the N95 face masks for 4 hours results in prolongation of the nasal mucociliary clearance as measured by STT. Susceptibility to any respiratory infection may be increased following doffing of the personal protective equipment, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) itself.

Is a Mask That Covers the Mouth and Nose Free from Undesirable Side Effects in Everyday Use and Free of Potential Hazards?

Many countries introduced the requirement to wear masks in public spaces for containing SARS-CoV-2 making it commonplace in 2020. Up until now, there has been no comprehensive investigation as to the adverse health effects masks can cause. The aim was to find, test, evaluate and compile scientifically proven related side effects of wearing masks. For a quantitative evaluation, 44 mostly experimental studies were referenced, and for a substantive evaluation, 65 publications were found. The literature revealed relevant adverse effects of masks in numerous disciplines. In this paper, we refer to the psychological and physical deterioration as well as multiple symptoms described because of their consistent, recurrent and uniform presentation from different disciplines as a Mask-Induced Exhaustion Syndrome (MIES). We objectified evaluation evidenced changes in respiratory physiology of mask wearers with significant correlation of O2 drop and fatigue (p < 0.05), a clustered co-occurrence of respiratory impairment and O2 drop (67%), N95 mask and CO2 rise (82%), N95 mask and O2 drop (72%), N95 mask and headache (60%), respiratory impairment and temperature rise (88%), but also temperature rise and moisture (100%) under the masks. Extended mask-wearing by the general population could lead to relevant effects and consequences in many medical fields.

Decontamination of surgical face masks and N95 respirators by dry heat pasteurization for one hour at 70°C.

BACKGROUND: The need for protective masks greatly exceeds their global supply during the current COVID-19 pandemic. METHODS: We optimized the temperature used in the dry heat pasteurization method to destroy pathogens and decontaminate masks while retaining their filtering capacity. RESULTS: The current study showed that dry heat at both 60°C and 70°C for 1 hour could successfully kill 6 species of respiratory bacteria and one fungi species, and inactivate the H1N1 indicator virus. After being heated at 70°C for 1, 2, and 3 hours, the N95 respirators and surgical face masks showed no changes in their shape and components. The filtering efficiency of bacterial aerosol for N95 respirators were 98%, 98%, and 97% after being heated for 1, 2, and 3 hour, respectively, all of which were over the 95% efficiency required and similar to the value before being heated (99%). The filtering efficiency for surgical face masks was 97%, 97%, and 96% for 1, 2, and 3 hours of heating, respectively, all of which were also similar to the value before being heated (97%). CONCLUSIONS: This method can be used at home and can significantly resolve the current shortage of masks.