The influence of particle size and composition on the quantification of airborne quartz analysis on filter paper

Fine particle quartz is considered as a lung carcinogen and therefore its monitoring in the workplace is currently required by government legislation across the world. In order to enforce the health and safety standards, techniques that can accurately determine the amounts airborne quartz are necessary. Currently, two techniques dominate quartz analysis--the infrared (IR) spectrophotometric analysis and the X-ray diffraction (XRD) method. Unfortunately, there are limitations associated with both techniques in terms of their analysis accuracy and this article discusses both these methods. The study showed that typical quarry quartz samples have a broad particle size distribution where up to 20% of the finer particles in the bulk sample material contain significant amounts of muscovite, kaolinite, rutile and others. This implies that quarry silica particles with a mean diameter of less than 5 microm contain significant amounts of other materials that are not quartz, and hence, would significantly influence the quantification of the particle composition analysis on filter papers used for air monitoring work places. The results of the study suggest that analysis of the fine fraction of a manufactured sample in a particular work environment should be considered as a reference standard for the quantification of the amount of airborne fine particulates an employee could be exposed to. The study also showed that the IR method is more sensitive and less subjective to sample preparation than the XRD method of analysis.