Dust at quarry entrances, with a focus on respirable crystalline silica (RCS)

Quarry entrances have a significant impact on the public perception of the extractive industry and are often seen as one of the associated ‘problem areas’ for quarrying. Mud and debris on public roads and concomitant dust may be of local concern if vehicles and road surfaces are not appropriately cleaned.

A study was undertaken to examine the character of dust at two quarry entrances and to investigate the presence of Respirable Crystalline Silica (RCS). Samples were collected using tripod-mounted personal sampling monitors with inlets for respirable dust (PM4) and from road surfaces at and near the quarry entrances. Specific attention was given to the characterisation of minerals, which might arise from quarry operations, using laser granulometry, X-Ray Diffraction (XRD) and Scanning Electron Microscopy-Energy-Dispersive X-Ray Spectroscopy (SEM-EDS).

This paper shows that the minerals detected are not always restricted to those that could be anticipated from the materials excavated at the quarry, but may reflect those associated with other on-site operations including waste disposal and recycling activities. The levels of RCS in samples at the quarry entrances were below detection limit and therefore not deemed to constitute a health risk.