Masks work regardless of who is convinced they don't. They work because a whole range of masks have been tested and rated for efficacy, where some of course are better than others.
Which is not to defend the Governments response during the Covid episode, which was abysmal.
Not everything is as black and white as your appear to believe.
Read the article. Try to understand what it says.
5. Conclusions
In the context of COVID-19, there is a paucity of systematic summaries on the filtration performance of protective masks. In this paper, the influencing factors and protective performance of masks are summarized. The conclusions are as follows:
Aerosol filtration mechanisms are divided into gravity sedimentation, inertial collision, interception, diffusion, and electrostatic interaction. The results for multiple mechanisms and a mechanism’s type of interaction are related to the aerosol particle size, airflow density, and material structure. However, in actual filtration mechanism processes, inertial collision, interception, and diffusion are important mechanisms for removing fiber aerosols, which is complex. Improving the efficiency of a filter is dependent on increasing the number of mask layers, reducing the fiber’s diameter, and reducing and changing the fiber’s structural density.
The influence of the aerosol size and type on filtration performance is not constant. Filtration efficiencies may increase with an increase in aerosol particles or decrease with a decrease in aerosol particles. However, generally speaking, for the same type of mask, the protection performance should improve with an increase in aerosol particles. The type of aerosol used is specific for a specific environment, and the aerosol used in a laboratory is engineered to not be harmful to people. The effect of gas flow rates on filtration efficiencies is very clear. The filtration efficiency decreases with an increase in the gas flow rate. The higher the filtration efficiency, the greater the pressure difference and increase in respiratory resistance. In addition, matching is a common problem observed in masks, and masks have improved matching performance with higher filtration efficiencies.
The respiratory resistance of a cloth mask, surgical mask, N95 mask, P100 FFR mask, and PARR mask increased in the listed order and as the filtration efficiency increased. In general, an increase in filtration efficiency will also lead to reduced comfort. However, if the thermal comfort performance of masks is improved, the cost and price of masks will increase. Therefore, on the basis of balancing the protective function and economy, it is recommended that the public should wear surgical masks to prevent COVID-19 infection in low-risk and non-densely populated areas.
Most researchers have focused on filtration efficiency and ignored the overall protective efficiency of masks. The filtration efficiency alone cannot explain the facial seal leakage and the fitting degree of a mask for a wearer.
Improvements are urgently needed for the degree-of-fit standards in order to improve the overall protective performance. In the future, it will be important to improve the matching degree and filtration efficiency of masks. Moreover, respiratory resistance should be controlled relative to the minimum acceptable range of the human body. In addition, biodegradable biomass mask materials also represent a future development trend because the full utilization of biomass energy could solve the environmental problems caused by the mass use of masks.
In conclusion, this paper provides detailed data to support experimental mask research, ideas for mask designers, a theoretical basis for the improvement of mask protective performance, and assistance for the formulation of standards. In addition, it contributes to human public health.''
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9915213/
