发布时间:2021-10-21 15:43:34浏览数: 0
Speaking of N95 masks for preventing smog and dust, let us first understand smog and PM2.5. Does smog=PM2.5? The main components of haze are sulfur dioxide, nitrogen oxides and inhalable particulate matter. Among them, the inhalable particulate matter is what we often call PM (particulatematter). What we often call PM2.5 is pollutant particles less than or equal to 2.5 microns in diameter.
What is the harm of PM2.5? Both are inhalable particulate matter, PM50 and PM10 can only reach our nasal cavity and throat respectively, and will be further advanced by the ciliated tissue. PM2.5 and particles smaller than PM2.5 can directly reach the alveoli and enter the entire blood circulatory system. Imagine a bunch of foreign objects, which are unsanitary by themselves, enter our body directly and circulate in the body. Not only can they directly harm our respiratory system and cardiovascular system, but they are also easy to attach toxic and harmful substances into the human body, which significantly increase the probability of causing cancer, teratogenesis, and mutagenesis. Therefore, it is necessary to choose a N95 mask to prevent smog and dust.
Search "N95 masks for anti-smog and dust" on Taobao. The prices of hundreds of varieties vary. Here we must first explain how dust masks combat PM2.5. Visually speaking, PM2.5 is small, but if we can cover the mouth and nose with a dense mesh, the mesh is smaller than 2.5 microns, then PM2.5 will not be isolated from the body? The "N95 mask anti-smog" we want is a super effective filter. Therefore, the key to the function of a mask is its physical filtering mechanism. It is quite unreliable to say that a certain filter element of dust mask can absorb PM2.5 or can eliminate PM2.5 by chemical means. The key point depends on the material of the anti-smog mask, and only professionally tested materials can filter PM2.5.
Can a haze mask made of cotton prevent PM2.5?
A cotton mask with sufficient layers can filter a considerable amount of dust and bacteria. However, urban air can inhale particulates and fine particles, and the filtration rate of cotton masks is less than 30%. The principle of this kind of fiber mask is a mechanical barrier. Through this layer of mechanical barrier, large particles can be blocked, but particles with a diameter of less than 5 microns cannot be blocked.
