一般居家的空氣污染程度，比室外高達 5 倍23
Wood-burning fireplaces and stoves emit particulate matter during combustion.
Foam that can be found in textile-covered furniture can release formaldehyde gas.
Some carpets, rugs and their backing materials can emit VOCs when new and potentially throughout their life.
Some chemical substances found in scented candles can release VOCs into the air as they burn.
Cats, dogs and other houshold pets can spread this microscopic material around the home.
Plants and flowers can release microscopic pollen into the air.
Sources such as tree pollen, particulate matter and vehicle exhaust fumes can enter the home and may remain trapped there.
Some household air fresheners can contain VOCs, which can be released alongside the fragrance when sprayed.
Gas hobs and the food cooking process itself can emit fumes and VOCs into the air.
Household cleaning products can contain volatile organic compounds that can evaporate into the air.