Changes in workplace concentrations of airborne respirable fibres in the European ceramic fibre industry 1987-1996

As part of a wider epidemiological research programme, an occupational hygiene study was carried out during 1995-1996 to assess workers' current exposures to airborne materials in six European refractory ceramic fibre (RCF) plants. These plants had also participated in a cross-sectional occupational hygiene survey in 1987. The sampling strategy focussed principally on personal shift-average exposures of workers, by occupation, to respirable fibres. Monitoring was undertaken in two integrated phases: a 1-week cross-sectional survey followed by a prospective, and ongoing, programme by the RCF industry. Statistical (analysis of variance) analyses to identify patterns of variability by plant, occupational group (OG) and occupations within group were based on 464 individual shift samples, the greatest amount of data being available for production occupations.Concentrations of respirable fibres showed marked differences between plants and between OGs. Average respirable fibre concentrations among Primary and Secondary Production and Ancillary workers ranged from <0.1 f ml^-1 to up to 0.4 f ml^-1, depending on OG and plant. Individual shift-average measurements were almost invariably <1 f ml^-1. Within Secondary Conversion and Finishing, plant-specific averages ranged from 0.3 f ml^-1 to 1.25 f ml ^-1. Respirable fibre concentrations were, in some plants, less than half those found in 1987. In other plants, mainly those where concentrations had been relatively low in 1987, the dust exposure had remained essentially unchanged or increased slightly.An ongoing programme of sampling is being carried out by the participating companies, generating additional information that could assist research in the long term and in improving control.