<prompt> Which of the following is not a indoor air pollutant?Carbon monoxideNitrous oxideRadonMercury  <response>: Major air pollutants from indoor sources include carbon monoxide, polycyclic aromatic hydrocarbons, nitrogen oxides, sulphur oxides, arsenic and fluoride and radon. Parks Textbook of Preventive and Social Medicine, 25th edition, Page No. 796 