Dissolution of finely divided single-constituent and multiconstituent beryllium aerosol materials associated with beryllium sensitization and chronic beryllium disease.
Stefaniak-A; Hoover-M; Day-G; Breysse-P; Scripsick-R
American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois. Fairfax, VA: American Industrial Hygiene Association, 2006 May; :52
Elevated prevalences of sensitization and chronic beryllium disease (CBD) have been observed in workers exposed to dusts, fumes, and particles of copper-beryllium at airborne concentrations of beryllium below the current permissible limit of 2 ug/m3. Particle dissolution within lung macrophage phagolysosomes is thought to be an important source of dissolved beryllium for input to the cell-mediated immune reaction associated with development of beryllium sensitization and CBD. We used a phagolysosomal simulant fluid in a static dissolution technique to measure the simultaneous dissolution rates of copper and beryllium from a copper oxide-beryllium oxide (CuO/BeO) fume aerosol material and the dissolution rate of beryllium from a finished product BeO powder. Observed dissolution rates were normalized to values of specific surface area (SSA) to calculate a chemical dissolution rate constant (k) for each material. Dissolution of beryllium from BeO powder was biphasic (9% of total dissolved was in the initial rapid phase and the remaining 91% was in the slower long-term phase); kBe values were 8 × 10-7 g/(cm2·day) (initial phase) and 7 × 10-9 g/(cm2·day) (long-term phase). Dissolution of copper from the fume aerosol material was rapid, consisting of a single phase (100% dissolved in 4.5 days); kCu = 8 × 10-7 g/(cm2·day). Complete dissolution of copper from the fume aerosol exposed inclusions of BeO, which exhibited biphasic dissolution behavior. The measured value of SSA for the fume differed from the SSA that governed beryllium dissolution, which precludes determination of kBe. The BeO inclusions would have higher SSA than measured for the total particle sample and beryllium would therefore dissolve at a proportionally higher rate. In summary, a BeO-containing fume aerosol generated during the manufacture of copper-beryllium alloy has bioavailability properties similar to single-constituent BeO powder, which may help to explain the risk of beryllium sensitization and CBD for workers who manufacture copper-beryllium alloys.
Aerosols; Aerosol-particles; Sensitization; Beryllium-compounds; Beryllium-disease; Diseases; Workers; Worker-health; Occupational-diseases; Occupational-exposure; Dusts; Dust-exposure; Dust-particles; Fumes; Fumigants; Immune-reaction; Exposure-levels; Exposure-assessment; Copper-alloys; Copper-compounds; Copper-fumes; Copper-dust
Research Tools and Approaches: Exposure Assessment Methods
American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois