A new personal sampler for airborne total dust in workplaces

This paper describes the development and testing of a new personal dust sampler for airborne ‘total’ dust in workplaces. The cornerstone of the work involves the use of a full-size tailor’s mannequin to represent the human worker both for the mounting of the personal samplers and as the reference against which the personal samplers are tested. This resultant evaluation is therefore consistent with the concept of inspirability which is now gaining acceptance as a biologically relevant criterion for ‘total’ dust. In the initial part of the work it was found that the performances of a number of commercially available personal samplers of the type currently recommended for the assessment of ‘total’ dust in workplaces are not only substantially different from one another but also substantially different from inspirability. A study of the parameters governing performance was then carried out, leading to the development of a new sampler comprising a 15 mm dia. circular entry through which air is drawn at 2 1. min −1 . It was shown that this sampler when worn on the lapel collects the inspirable fraction of airborne dust satisfactorily over a representative range of particle aerodynamic sizes and wind speeds. The design incorporates a dust-collecting cassette which has the advantage of minimizing errors due both to particle blow-off from external surface and to internal wall losses.