Air pollution significantly increases cardiovascular morbidity and mortality. During several past years, attention was drawn to Indoor Air Pollution (IAP) and its possible role as a risk factor for cardiovascular disease. National Human Activity Pattern Survey (sponsored by the Environmental Protection Agency) demonstrated that people spend most of their time indoors (up to 87%). While indoors, they are exposed to indoor air pollutants generated by cooking, combustion of biomass fuel (BMF, wood, charcoal, etc), use of electrical appliances, fireplaces, smoking and by ozone-associated chemical reactions involving household elements (e.g. linoleum, paint, adhesives, particle filters, ventilation ducts etc.). A significant source of Indoor Air Pollution (IAP) is smoking. Importantly, both mainstream and exhaled cigarette smoke generates fine particles (aerodynamic diameter ≤2.5 μm, PM2.5). Study of air quality in 66 US casinos revealed that in the smoking casinos means PM2.5 concentration was 53.8 μg/m3 vs. 4.3 μg/m3 outside those casinos.