N95 Mask

The images show three separate layers of an N95 mask. I thought of using the fibres of the mask as a sample because I was curious to know if masks were truly effective in filtering out pathogens and polluting particles. The first and second images are of the inner layers of the mask, while the last image is of the outermost layer of the mask. The first image of the series shows what appears to be particles of dirt and some unidentified objects.

The second image in the series shows what appears to be dust particles again, along with another identified strand-like object. At first glance, it looks like a strand of hair. It cannot, however, be a human hair as this object would be too small to appear at the size it does in the image.

The last image in the series is of the outermost layer of the mask. We can see the individual fibres of this layer, and how big the spaces are between the strands of the fibre. This layer is not the last line of defence, so it seems logical that the spaces in this image would be slightly larger than the two previous images. The actual spaces in the first two images are still so small (despite the apparent size due to magnification) that it still looks like a complete fabric. This is consistent with the promises made by manufacturers as the spaces seem to be small enough that particles of sizes in the order of micrometers.

An N95 respirator or surgical masks are part of the personal protection equipment kits that medical workers wear when why they carry out their jobs in medical laboratories and hospitals. They are particularly effect when dealing with diseases, as they protect medical workers from being infected by pathogens, particularly airborne pathogens. The name N95 comes from the fact that this type of mask is designed to filter out around 95% of airborne particles. The mask is designed to filter out any particles that are larger than 0.1-0.3 micrometers (about 0.1*10-6m – 0.3*10-6) in size[1].


[1] Qian, Y., Willieke, K., Grinshpun, S., Donnelly, J., & Coffey, C. (). Performance of N95 respirators: filtration efficiency for airborne microbial and inert particles. American Industrial Hygiene Association Journal. 59(2). 128-132. https://doi.org/10.1080/15428119891010389

 

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