The generation of dusts in the workplace can pose a significant health risk to workers. Dusts can be generated from a variety of materials including wood dusts, flour and grain dusts, silica and heavy metal dusts to name a few. The health risk of a substance depends on its chemical composition. For example, hardwood dusts are confirmed human carcinogens, whereas flour dust is a known sensitising agent and can cause allergic reactions. All airborne dusts in the workplace are considered to be substances hazardous to health and may cause obstructive lung disease.
Dusts in the workplace are categorised into respirable and inhalable dust fractions. Inhalable dust is the total portion of dust that can be taken in through the mouth and nose during breathing.
Respirable dust corresponds to the portion of total dust that is 10 microns in size and smaller, this is dust that can penetrate and deposit in the lower bronchioles and alveolar region of the lungs.
Personal exposure monitoring for dusts is undertaken using a sampling pump worn on the belt of a worker that is connected to a sampling head by flexible tubing. The sampling head is placed in the workers breathing zone (within 30cm of the nose).