Section III provides the scientific and occupational health foundations needed to understand silica, respirable crystalline silica and other hazardous workplace dusts and contaminants. It explores the mineralogical characteristics of silica, how respirable dust is generated, and the occupational and non-occupational pathways through which workers and communities can be exposed.
The section also examines coal dust, welding fumes, lead and other airborne contaminants that can contribute to occupational lung disease and broader health impacts. In addition, it reviews the historical progression of silicosis and pneumoconiosis, including past elimination efforts, the global resurgence of dust diseases and the emergence of new exposure risks associated with engineered stone and other modern industries. Together, these resources provide essential background on the causes, sources and evolution of silica-related and dust-related diseases, supporting a greater understanding of prevention and risk management.