... disease and pollution (Theophanides, M 20 02 , 20 07; Touloumi et al 1994, Katsouyanni 20 03, Katsouyanni et al 1997, Ballester, et al 1996, Arribas-Monzón, et al 20 01) 1 .2 What is air quality? Air ... elderly, children and those already afflicted with health problems 4 Indoor and Outdoor Air Pollution Several studies (M Theophanides et al 20 07, 20 07, Touloumi et al 1994, Katsouyanni 20 03, Katsouyanni ... 8 Indoor and Outdoor Air Pollution Gas Description CH4 H20 CO NO2 O3 C6H6 Methane Water Vapour Carbon monoxide Nitrous dioxide Ozone Benzene Molecular weight 16 18 28 46 48 78 Vm/M 1.4194 425 ...