on behalf of the British Occupational Hygiene Society doi:10.1093/annhyg/meq055 Characteristics of Beryllium Exposure to Small Particles at a Beryllium Production Facility

Epidemiological studies have reported process-specific elevated prevalence of beryllium sensi-tization (BeS) and chronic beryllium disease (CBD) among workers. However, exposure– response relationships have been inconsistent, possibly due to incomplete characterization of many biologically relevant aspects of exposure, including particle size. In 1999, two surveys were conducted 3–5 months apart at a beryllium metal, oxide, and alloy production facility during which personal impactor samples (n 5 198) and personal 37-mm closed-face cassette (CFC) ‘total ’ samples (n 5 4026) were collected. Among process areas, median particle mass median aerodynamic diameter ranged from 5 to 14mm. A large fraction of the beryllium aero-sol was in the nonrespirable size range. Respirable beryllium concentrations were among the highest for oxide production [geometric mean (GM) 5 2.02 mg m23, geometric standard de-viation (GSD) 5 1.3] and pebbles plant (GM 5 1.05 mg m23, GSD 5 2.9), areas historically associated with high risk of BeS and CBD. The relationship between GM ‘CFC total ’ and GM respirable beryllium for jobs varied by process areas; the rank order of the jobs showed high overall consistency (Spearman r5 0.84), but the overall correlation was moderate (Pear-son r 5 0.43). Total beryllium concentrations varied greatly within and between worker