AIC's 42nd Annual Meeting

The accumulation of dust in museums and other indoor collections is a basic concern for collection management and conservation. Dust can be found everywhere, even in the best-kept museums with the most modern air conditioning and filtering systems. High levels of dust accumulation mean that showcases and objects must be cleaned more often, which implies higher maintenance costs for a museum, as well as more frequent treatment of objects. Dust also affects the perception of visitors as well as professionals of how well a collection is kept. In the extreme case, years of dust accumulation and poor environmental conditions can lead to degradation of materials.

In 2005, three Dutch museums reported possible problems with “too much” dust in their exhibition areas. Two of those museums were concerned about possible effects of dust raised by construction work occurring right next door, while the third was looking for the cause of a noticeable increase in dust accumulation in and around showcases, and leading to overheating of several projectors. In response to these issues, the Netherlands Institute of Cultural Heritage, now the RCE, conducted a study of dust accumulation in these three museums. An important result of this work was a simple and inexpensive method for measuring the rate of dust accumulation.

The method involves measuring the rate of change (loss) in gloss of standard glass microscope slides and using this as a measure of the rate of dust accumulation. Standard glass microscope slides (e.g. 25 x 75 mm) are placed next to objects or at locations of concern. They have the advantage of being easy to hide or are virtually invisible to visitors. The change in gloss (loss) as dust falls on the slides is measured regularly over a given period of time using a commercially available gloss meter. This data is used to calculate the rate of accumulation of dust over the measurement period.

Chemical analysis of the dust was conducted using energy dispersive spectroscopy (EDS/EDX) in a scanning electron microscope (SEM) by collecting samples on conductive carbon stickers which were placed next to the slides. The area coverage of dust was also determined by image analysis of micrographs of the stickers taken in the SEM. The combination of the gloss measurements and the EDS/SEM was used to determine the source of dust during the accumulation period.

The results of the study show that the rates of change of gloss and area coverage can be directly related to changes in activity in and around the museums. It confirmed earlier research that visitors are one of the main sources of dust in museums. The effect of construction, traffic, and seasonal changes could be seen both as changes in gloss as well as changes in chemistry. Gloss measurements are simple to use, and the analysis of the results can be easily carried out using a simple program, which can be written in, for example, Microsoft Excel.

The measurements are also inexpensive to carry out, requiring only a modest investment for the glossmeter.