Standardization of Cab Air Quality: Defining Dust
What is dust? Is it harmful? Before we tackle these, we need to understand what aerosols are, allowing us to determine where dust fits in. So, what are aerosols? Aerosols are a group of liquid or solid particles that are very small (0.001 to 100um in size – 1000um = 1mm), suspended in a gaseous medium. They can be naturally occurring or artificially produced in ambient (the community) and industrial air environments. They vary significantly in size, shape, chemical composition, and density. Aerosols can include dust, fume, and mist. Aerosols found in the workplace vary widely in size. Those visible to the human eye range from 100um – to 10,000um).
Now, onto dust. Dust is found everywhere. Dust is usually comprised of solid particles formed due to the crushing of parent material, e.g., rocks, or other mechanical processes, e.g., natural weathering. Dust has become one of the most significant exposure risks in the workplace and, more broadly, in society (e.g., very fine dust in cities from motor vehicles and industry).
From an industrial perspective, dust is created from many tasks carried out by specific industries and workplaces. Examples include mining, crushing, sieving, milling, cutting, grinding, planning, machining. These activities create dust that can be emitted into the atmosphere if not controlled at the source.
So is there a dust issue? Many activities may not create dust or, if created, are relatively harmless (known as nuisance dust). However, breathing dust can give rise to illness (in the workplace - occupational) and permanent respiratory (lung) disorders when not effectively controlled to prevent exposure to the worker.
The size, quantity, and types of dust that are harmful to humans to breathe have been identified by medical science. As we consider standards for operator enclosures, it is reassuring to know that the engineering controls required by ISO 23875 effectively prevent dust from entering and remaining airborne in the cab.
We hope to inform and provoke a conversation with our readers and learn what interests them.
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(Ref: Reed et al., 2013. Principles of Occupational Health & Hygiene. A&U, Australia.
AIHA, 2011. The Occupational Environment: Its Evaluation, Control, and Management, 3rd Ed. AIHA, USA).