ABSTRACT
This chapter defines the terms respirable, inspirable and inhalable dusts, and describes occupational hygiene monitoring techniques to sample and analyse these contaminants in Australia. It describes the physiological effects of exposure to dusts, particularly crystalline silica, asbestos, synthetic mineral fibres and wood dusts. Dust-related disease and ill health can be traced back to historical times. It was Hippocrates who identified that inhaled dust could affect health. Occupational asthma has been reported from dust exposure to substances such as grains, tea, bagasse and high-molecular weight animal proteins. Total dusts have little occupational hygiene significance and should not be monitored in the workplace, except where the distribution of the dust cloud is sought. Cyclone elutriators operate on the principle of centrifugal impaction of dusts. Dust-laden air enters the inlet and is circulated in a centrifugal motion into the cyclone. Silicon is one of the most widely spread elements on earth. Indeed, the majority of the rocks in the earth's crust are silicates.
