Sources

Contaminant	Source

Asbestos	some insulation installed between 1930 and 1950 some old wood stove door gaskets some vinyl floor tiles drywall joint compound and textured paint obtained before 1977 cement-asbestos millboard, exterior wall shingles some ceiling finishing plaster installed between 1945 and 1973 some fire retardant on structural steel

Combustion by-products	power generation (gas, coal, oil) wood and coal stoves internal combustion engines fireplaces candles

Tobacco Smoke	cigarettes cigars pipes

Formaldehyde	some particle board, plywood, pressed-board, panelling, carpeting, carpet backing some furniture and dyes urea-formaldehyde insulation foam some household cleaners, deodorizers combustion some glues and resins cosmetics permanent-press clothing

Biologic organisms	fungi, including mould and mildew animals humans

Radon	gas emitted by soil, rocks, water natural gas granite building materials

Volatile organic compounds	solvents and cleaning compounds paint glue spray propellants fabric softeners and deodorizers and perfumes combustion dry cleaning fluid some fabrics petrol water outgassing building materials wax and polishing compounds pens and markers binders and plasticizers