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

Abstract

Literature was systematically reviewed regarding CO exposure and facemask use. Observational and experimental data are helpful for a risk-benefit assessment for masks as a popular non-pharmaceutical intervention against SARS-CoV2 in the populace. Masks impede breathing by increasing the resistance and dead space volume leading to a re-breathing of CO with every breath taken. Fresh air has around 0.04% CO, while wearing masks more than 5 minutes 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 consequences must be considered due to experimental data. US Navy toxicity experts set the exposure limits for submarines carrying female crews to 0.8% CO based on animal studies indicating an increased risk for stillbirths. Additionally, in mammals chronically exposed to 0.3% CO experimental data demonstrates teratogenicity with irreversible damage of neurons and reduced spatial learning caused by brainstem neuron apoptosis and a reduced blood level of the insulin-like growth factor 1. With significant impact on three readout parameters (morphological, functional, marker) this chronic 0.3% CO exposure has to be defined as being toxic. Additional data exists on the exposure of chronic 0.3% CO in adolescent mammals causing neuron destruction, which includes less activity, increased anxiety and impaired learning and memory. 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. Extended masking in pregnant women, children and adolescents has not been thoroughly tested and studied. As a result of the animal experimental data available, a risk-benefit analysis is urgent and a need exists to rethink mask mandates, which provide appropriate warnings.

WITHDRAWN: Physio-metabolic and clinical consequences of wearing face masks -Systematic review with meta-analysis and comprehensive evaluation

“…was lower (absent or even reverse) than expected 115,131,132 . In former human experiments with low level 1-2% CO 2 exposure to breathing air -which corresponds to measured values during mask use 133 -an increased respiratory minute volume (V E ) of >34% was detected 115 . In contrast to that and according to our results under masks a significantly decreased V E by -19% on an average and up to -24% under N95 masks occurs despite face mask driven CO 2 exposure 133 .…”

“…no rise in respiratory rate, heart rate and simultaneous fall in V E ). Health risks should be considered despite the mask related compensation attempts 133 . During face mask use a rise in the arterial PaCO 2 is possible in the long term 20,52,58,60,98 .…”

“…obvious for CO 2rebreathing. However, immediate compensatory mechanisms can hide further adverse reactions 115,131,133 . Therefore, longer observation times can lead to clearer values that are closer or above the thresholds due to the attenuation or collapse of transient physiological mechanisms.…”