ABSTRACT
Environmental pollution has been increasing in the atmosphere because of the increase in exhaust gases emitted by internal combustion engines, boilers and so on. Exhaust gases contain harmful NOx as well as PM2.5 (particulate matter 2.5) that is suspected to cause lung cancer and other diseases. Indoor air pollution has also been increasing because of cigarette smoke and the increase of emission of VOCs (volatile organic compounds) from new synthetic building materials. VOCs are considered to be the main cause of sick house syndrome. At the same time, the number of people who are allergic to organic floating particles such as pollen and house dust has been increasing. Although human noses are
sensitive to some toxic gases and odors such as burnt odor, human noses cannot detect many harmful gases such as CO and organic floating particles. Therefore, it is required to develop sensors for those airborne materials.
