I read a humourous line recently: ‘Dust is a protective coating for fine furniture’. Obviously that’s a joke, but the joke is more about perceived standards of housekeeping than the realisation that dust is anything but protective.
Preservation specialists have known for a long time that it is actually harmful, so much so that the very image of a museum curator is bound up with dustiness. That’s why, upon telling people I was a curator, often the response was ‘Do you do a lot of dusting?’ A good collection won’t be like this – a good collection excludes it in the first place.
So what’s the problem? Well, it’s unsightly, it’s acidic, it’s abrasive, it’s allergenic and it’s hygroscopic. Dust comprises particles of soil, sand, volcanic eruptions, pollution, pollen, exhaust fumes, mould and fungi spores, of dead skin and hair, fabric and paper fibres and house dust mites, which eat the organic matter contained within and leave their faeces behind them.
The overall composition is acidic, and if left, will eat away and etch into items if left lying upon them. It will discolour and stain fabrics. Dust is mainly organic and as it decomposes it rots, leaving the products of decay in its wake.
Fibrous dust only contributes about 3% to the total but as it’s larger, it is unsightly; it is the fibres in the dust that often alert us to its presence. Skin and hair also don’t contribute much, but in homes and offices, they create enough particles to ensure the presence of house dust mites. Microscopic louse-like creatures, these cosmopolitan pyroglyphids flourish in these stable environments. Particularly fond of warm, humid bedding, they also do well in carpets and soft furnishings in similar office environments.
Dust sticks to surfaces because of the presence of exopolymers, made of the waste products of microbes. As dust gathers it provides more food for the colony-forming microbes which produce waste (called ‘biofilm’) on the surface of your object. Warm humid rooms are perfect for this breeding to take place.
To avoid the heavy consequences of ruining a collection with this problem, exclude it. Gently vacuum items before boxing or covering them. Don’t use a duster as this just moves and unsettles it – use a conservation vacuum. Items which don’t need boxing can be protected with archival tissues but not all items need this protection. These can be shelved as long as the doors and any windows are sealed or have excluders. Ideally a store wouldn’t have windows at all – if it does, they should be boarded over and sealed up – this helps with security, excludes dust, stabilises temperature and humidity and maintains low light levels.
If stringent precautions are taken and a regular cleaning programme implemented then your collections should be an asset to your company for many years to come.