Ключевые слова: air, allergy, background, breathing, care, clinic, cough, disease, disposable, dust, epidemic, equipment, face, filter, flu, hand, health, health care, hygiene, hygienic, ill, illness, infection, influenza, mask, medical, medicine, object, pm10, pm25, pollution, prevention, protect, protection, protective, safety, science, sneeze, surgical, virus, wearing, white,