11 AIR FILTERING SYSTEMS COMPRISING AIR FILTERS FOR COMMERCIAL, INSTITUTIONAL, MEDICAL AND INDUSTRIAL USE, PARTICULARLY IN ELIMINATING AIRBORNE CONTAMINANTS AND PATHOGENS; FILTERING PRODUCTS, NAMELY, AIR FILTERS FOR COMMERCIAL, MEDICAL AND INDUSTRIAL INSTALLATIONS AND MINUTE PARTICLE AIR FILTERS; AND PARTICULATE REMOVAL APPARATUS, NAMELY, HIGH EFFICIENCY PARTICULATE AIR FILTERS