Dust Characterisation and Analysis

Dust Analysis

Dust monitoring samples are scanned into our software and processed to determine the Absolute Area Coverage (AAC) and Effective Area Coverage (EAC) for each sample.

• %AAC is the coverage of dust, irrespective of colour. So long as it can be seen in the scanned image, any dust, pale or dark can be recorded as AAC. As a result, AAC is a very sensitive measure and is especially effective in detecting low levels of dust which might not show up by other dust analysis methods.
• %EAC is the darkness or greyscale discolouration of dust and is used as a measure of dust soiling. Unlike AAC, EAC is a measure of the darkness, or soiling caused by dust, so for the same colour dust (be it chalk or coal), %EAC generally increases with dust coverage. %EAC is typically higher when the majority of the dust is darker in colour.

In combination, DustScan has developed a widely-recognised dust annoyance ‘risk assessment’ protocol, combining dust coverage as %AAC and dust soiling as %EAC. These data are combined to produce dust annoyance risk values which can be used as Key Performance Indicator (KPI) values when assessing site performance.

Dust Characterisation

DustScanAQ also provides a range of dust characterisation analysis services to investigate ‘what is in the dust’. Using our expertise, in-house analytical equipment and trusted accredited third-party laboratories across the UK, we can advise on the best dust analysis service for you.

Dust analysis methods we frequently use include:

• Optical light microscopy – identification of common types of dust particles based on expert interpretation of visual properties and particle size and shape when viewed under high magnification different lighting conditions;
• Scanning Electron Microscopy Energy Dispersive X-Ray Spectrometry (SEM-EDXS) – higher magnification analysis which can distinguish between visually similar materials by looking at their basic chemical makeup;
• Inductively Coupled Plasmas – Optical Emissions Spectrometry (ICP-OES) – quantitative analysis for specific elements, typically used for heavy metals such as lead or arsenic;
• X-Ray Diffraction (XRD) – mineral identification analysis which can provide relative proportions of specific minerals present such as quartz (crystalline silica) or calcite;
• Polarised Light and Dispersion Staining Microscopy – Asbestos screening analysis used to determine the presence/absence of asbestos within a dust sample.

There is no singular dust analysis service that can provide you with all of the answers however at DustScanAQ we review your interests and concerns or the types of materials that could be present based on background information available and advise on the most appropriate dust analysis methods.

We often carry out dust analysis on uniform materials (reference samples) before analysing dust samples collected from areas of concern or collected by our dust monitors to help establish whether the reference materials are present and, if so, to what extent. Through our knowledge and expertise, we can also identify many common materials present using our dust analysis service without the need for reference samples.