Why is there so much dust at home? Sources and ways to reduce it

What is house dust made of?

House dust is not a single substance; it is a mix of many small particles:

• From outside: Road and soil dust, construction dust, pollen, soot and grime.
• Formed indoors: Fibres shed by clothes, rugs and upholstery, skin flakes, hair and pet fur.
• Of living origin: House dust mites and their waste, mould spores.

The mix varies from home to home. In a home facing a main road, near a building site or in a windy area, the share from outside is much larger.

How can you tell dust is coming from outside?

A few simple observations give you a clue:

1. If windowsills and ledges darken within a few days, much of the dust is coming from outside.
2. If the dust colour is grey-black and slightly greasy, it may be soot from traffic and chimneys.
3. If furniture near the window gets dusty faster than furniture further inside the room, the source is the window.
4. If after windy days you see a clear increase, the share from outside is high.

What can you do to reduce dust?

For dust from outside

• Use a window filter. A nanofiber window filter fitted like an insect screen lets air through while holding most dust back at the window. You do not have to keep the window shut. Window dust filter
• Choose when you air the room. Air early in the morning or late at night rather than at rush hour.
• Put a doormat at the door. Soil carried in on shoes is also a major source.

For dust formed indoors

• Wipe with a damp cloth. A dry duster just lifts dust into the air.
• Use a vacuum cleaner with a HEPA filter. The air it blows out does not put the dust back.
• Cut down on textiles. Rarely used cushions, throws and rugs collect dust.
• Wash bedding in hot water. It reduces dust from mites.

In short

Regular cleaning for dust formed indoors, a filter at the window for dust from outside. Used together, your cleaning stays effective for much longer.