1. Tinminers and granite King et al. (1956)
2. In two other cases of acute silicosis (Einbrodt, Graber, and Fitzek, 1957), the total lung dust, isolated by the formamide method, amounted only to 4 and 6 g. and the quartz present in the dust was of the order of 40 %. It is not certain that the values refer to complete lungs
3. The first series of over 30 analyses of South Wales coal-miners' lungs, published by Cummins and Sladden (1930), cannot be used for our purpose because no distinction between free and total silica was made; this series appears to have included a high proportion of rock workers in coal-mines with silicotic lung changes. It is possible, however, to use the figures for total (ash-free) coal isolated by nitric acid digestion of the lung tissue. The amounts of coal present in both lungs ranged from 5 to 119 g. and the six highest values, for colliers and hard heading workers, were;119, 104, 97, 77, 52 and
4. analysed over 40 coal-miners' lungs from various coalfields in Australia. Their method has been described above and their data were evaluated in the same way as those of silicotic lungs, i.e. the weights of combined silica were doubled to give the amount of siliceous minerals other than quartz;g. coal. Badham; Taylor,1938
5. Coal-mining and handling covers a variety of occupations; changes in the composition of the dust for different occupation groups are reflected in the composition of the dust recovered from the lungs. This has been shown by King and Nagelschmidt (1945) in a study of 54 lung residues of coalworkers from South Wales. The proportions of rock dust decreased from 75 % of the total lung dust for rock workers to 5 % of the total dust for screen workers and trimmers. The largest group of men exposed to dust were colliers, and the lung dust found in colliers was intermediate in composition, containing on an average, 15 % of rock dust (mainly mica and kaolin) and 2-2 % of quartz