Bulk Dust Analysis
Nuisance dust (often referred to as ‘fugitive dust’) can manifest itself in many ways, and may appear and increase in prevalence over time:
- in the general workplace environment
- on shelves and parcels in warehouses (as a result of ingress from external sources or vehicle movements within the building)
- on outside structures (e.g. windowsills) and vehicles parked outside workplaces.
Nuisance (or fugitive) dust deposits may also appear in unexplained circumstances inside or outside domestic premises.
Deposits of this nature can often be traced to a definitive source, which may be construction or demolition operations, landfill or waste disposal activities, factory processes (from stacks and emissions) site remediation and restoration, movement of dry materials around sites and occasionally as a direct result of prevailing wind conditions carrying dust deposits from abroad.
If you have concerns regarding dust deposits, they can be collected in a number of ways for analysis:
Bulk dust, where there is a significant amount of deposit can be collected by brushing into grip seal bags.
Smaller deposits may be collected onto adhesive (‘Fablon’) strips, adhesive tabs for convenient presentation to a Scanning Electron Microscope; or cotton wool/cotton buds where the deposit can be washed and redeposited on to a cellulose nitrate filter.
Analysis of the samples can then be carried out using a variety of techniques including:
- Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) to provide information on the surface composition of the dust and classification/relative quantification of the individual particles within the sample (e.g. siliceous material, plant/animal fragments, carbonaceous matter, fly ash, dirt particles) which will assist in determining the source of the dust.
- Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) to determine the presence and type of airborne fibres present within any collected deposits, which is of particular importance should the potential presence of asbestos be a cause for concern.
- ICP-MS & ICP-OES to determine presence and concentration of metallic elements within the dust
- GC-MS to determine presence of organic species (Phenols, PAH compounds, Polychlorinated Biphenyls [PCB’s) within the dust (subject to there being sufficient sample)
- Particle sizing techniques to determine the particle size range of the collected deposit and determine whether any occupational dust monitoring should be undertaken on employees who may be exposed to the dust during their routine work activities.
The analysis results are presented in tabular and chart format; and once evaluated can be used to determine whether further investigation is warranted if a potential dust source is identified.
This will often be a fugitive dust sampling exercise typically conducted over a 6 – 12 week period using passive dust sampling techniques (e.g. Frisbee deposition gauge, Adhesive Strip) and laboratory analysis, which can be augmented using instrumental dust monitoring methods; the results from which are used to provide a comprehensive environmental dust survey report incorporating a comparison of the measurements against documented environmental dust deposition guideline values.