Hamilton. The first results from the PFR were reported in 1970 in the scientific journal Nature. The research underpinned the recommendations for more stringent airborne dust standards in British coalmines and the PFR was ultimately used as the basis for many national dust standards around the world. IOM's research in coal mining continued until about 1990, with many important scientific papers on respiratory diseases amongst miners having been published. In 1985, an important association between risk of pathological emphysema and dust exposure was demonstrated, leading ultimately to recognition of this disease as a quantifiable risk of coal mining. Recent analysis of the mortality of a subset of the miners originally studied has found an association between the risk of lung cancer and quartz exposure, and raised mortality from chronic lung disease and pneumoconiosis associated with increasing dust exposure. In the 1980s the IOM's epidemiological expertise was used in three original studies led by Dr Anthony Seaton into the effects of polyvinyl chloride dust, wool dust and shale mining on the lung health of workers. All showed positive associations and the results were used in regulatory standard setting in the UK and United States. This research into risks from inhaling dusts remains an important part of the IOM's research. The occupational exposure limits for crystalline silica continue to be a major international concern and from its previous research IOM has been able to define an exposure-response relationship for crystalline silica with unusual precision. This work demonstrated the need for very low limits on exposure to airborne crystalline silica because of the high risk of disease from even relatively brief exposures to high airborne concentrations. IOM studies have defined the relationships between decreases in lung function and dust concentrations amongst coal miners. These studies showed that dust control sufficient to prevent pneumoconiosis would reduce substantially the risks of impairment of lung function. However, an important question was whether these risks could be extrapolated to other occupational insoluble dusts. By developing and validating mathematical models of accumulated lung dust burden and resulting inflammation, IOM research has shown that the toxicity of several insoluble dusts of different compositions can be predicted from their surface area. Asbestos and other mineral fibres In 1971, Dr John MG Davies was recruited from Cambridge University to head a new Pathology Branch at IOM, and to continue his research into asbestos-related diseases. An extensive programme of research on the