Respiratory health of Scottish quarry workers. Identification of a study population, collation of radiographic and environmental data, and preliminary results. Final report on HSE Research contract 1/MS/126/548/86

Identification of population and collection of baseline data: This project was designed to identify all workers currently employed in hard rock quarries in Scotland, and to obtain occupational and smoking histories from them. Under the quarry “”Owners control scheme for respirable dust””, measurements of respirable dust and quartz were made on a regular basis, and chest radiographs were taken of the workforce. All these data were obtained and organised systematically so that a prospective study as well as a cross-sectional survey could be based on this population, if desired at a later date.One hundred quarries were identified in the “”Owners control scheme for respirable dust”” originally promoted by HM Principal District Inspector of Mines and Quarries (Scotland). Men at 72 of these quarries participated in the medical survey and 1322 workers were identified. Of these, 1257 gave occupational histories, 1149 had chest radiographs and 1104 had both. The identities, addresses and national insurance numbers of these subjects, their X-ray films and their occupational histories were retained in medical confidence, and securely.Data from one or more environmental studies in 80 quarries, including at least four surveys each in 31 of these, had been collated by September 1989. Thus,information on concentrations of respirable dust and respirable quartz in quarries was available from 244 surveys overall, involving 846 samples.Preliminary interim analysis: The X-ray films were classified by medical readers and by a non-medical panel. Preliminary statistical analysis suggested that the confidence intervals for the prevalence of a reading of profusion of 1/0 higher ranged from 2% to 7% of the study population. Initial analysis and review of the environmental sampling data indicated that for the workers in crushing and screening of quarts-containing rock, the mean exposures to respirable quartz were substantially higher than the occupational exposure standard. “”