The infectious diseases are spread through virus and bacterial infection either in outdoor or indoor atmosphere is responsible to carry the virus. It is discover that there are more than 350 dust particles always present in the indoor room temperature. It such a case it is necessary to protect from the viruses, bacteria and moulds, pollen etc. There are various sources in the atmosphere that spread the allergies and asthma. In USA average person spends most of the time in indoor and the indoor air pollution have the highly polluted than the outdoor pollution.
The Respirable Suspended Particulate Matters of less than 4 to 5 microns that enter into the nasal membrane and enter into the lungs that causes normal allergy, asthma and several other types of infectious diseases like flu, viral infections and bronchitis etc. We must have to take the preventive measures like installing the room air purifier and if you have any symptoms of fever or any types of allergy symptoms than it is necessary for you to contact the doctor and get the treatment on time.