• Radon

• Carbon monoxide

• Dust, pollen and pet dander

• Secondhand tobacco smoke

• Asbestos in floor tiles or insulation

• Pressed-wood or particleboard products made with formaldehyde

• Chemicals in household cleaning products, air fresheners and personal care products such as aerosol sprays

• Combustion sources such as oil, gas, kerosene, coal and wood

• Outdoor pollution sources such as pesticides transferred inside on shoes

• Vinyl, which releases Volatile Organic Compounds

• VOCs in paints, solvents, adhesives, finishes, carpeting and pads

• Sealant and fire-retardant chemicals in fabrics and upholstery

• Open-combustion appliances such as furnaces or water heaters, which produce carbon monoxide

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