We have been using HEPA air purifiers purchased from Amazon for years and thinking buying a new one. However, I just know that while HEPA filter can remove up to bacteria, dust and allergens up to 0.3 microns which means 300 nanometers, an Ebola virus at 200 nanometers is 0.2 micron, the Rhinovirus at 30 nanometers is 0.03 micron (three general groups of health threat microbes are apparent from physical size; viruses, bacteria, and fungal/bacterial spores).
Does it mean that our technology are already that obsolete?