Lung dust and lung iron contents of coal workers in different coalfields in Great Britain.

160-168. Lung dust analyses from seven coalfields are studied and it is found that the average dust composition varies significantly with the rank of coal. The higher the rank, the higher the coal percentage and the lower the quartz percentage of the lung dust. This holds for all coalfields except in Scotland, where the lung dust contains mainly soot instead of coal. Samples of airborne dust collected at the coalface in different coalfields show a similar but small variability of composition with rank of coal, and the results from Scotland are in good agreement with the results from other coalfields. The amount of iron in simple pneumoconiosis lungs is related to their mineral and coal contents and to the factor `years underground'. The strongest relationship is with coal and mineral for coalface workers from England. For pit accident cases (all simple pneumoconiosis) mineral is important as well as years underground, while for simple pneumoconiosis cases from Scotland, years underground is the most important factor.