title: Pulmonary retention of ceramic fibers in silicon carbide (SiC) workers.
abstract: The fibrous inorganic content of post-mortem lung material obtained from 15 men who worked in the primary silicon carbide (SiC) industry was evaluated. Five men had neither lung fibrosis nor lung cancer (NFNC), six had lung fibrosis (LF), and four had lung fibrosis and lung cancer (LFLC). The workers had 23 to 32 years of exposure. Mean duration of exposure was 23.4 (SD 6.9) years in the NFNC group, 28.8 (SD 5.5) in the LF, and 32.3 (SD 9.0) in the LFLC group. Concentrations of SiC ceramic fibers and other fibrous minerals and angular particles were determined by transmission electron microscopy and energy dispersive spectroscopy. The geometric mean and geometric standard deviation lung concentrations of SiC ceramic fibers < 5 microns were not statistically different for the three groups (Mann-Whitney, p > 0.1). Pulmonary retention of SiC fibers > or = 5 microns showed an excess in LF and LFLC cases combined versus NFNC that approached statistical significance (Mann-Whitney, p = 0.06). There was a somewhat greater difference for lung retention of ferruginous bodies between NFNC and either LF or LFLC cases (Mann-Whitney, p = 0.02). SiC fibers > or = 5 microns and angular particles containing Si and especially ferruginous bodies were found at higher concentrations in LF and LFLC than in NFNC cases.
authors.affiliation: McGill University, Department of Occupational Health, Faculty of Medicine, Montreal (Quebec), Canada.
authors.forename: A
authors.initials: A
authors.lastname: Dufresne
authors.forename: P
authors.initials: P
authors.lastname: Loosereewanich
authors.forename: B
authors.initials: B
authors.lastname: Armstrong
authors.forename: C
authors.initials: C
authors.lastname: Infante-Rivard
authors.forename: G
authors.initials: G
authors.lastname: Perrault
authors.forename: C
authors.initials: C
authors.lastname: Dion
authors.forename: S
authors.initials: S
authors.lastname: Massé
authors.forename: R
authors.initials: R
authors.lastname: Bégin
mesh_terms: D000395:Air Pollutants, Occupational / Q000302:isolation & purification*; D002244:Carbon; D017554:Carbon Compounds, Inorganic; D002516:Ceramics / Q000302:isolation & purification*; D006801:Humans; D008168:Lung; D008175:Lung Neoplasms; D008297:Male; D008854:Microscopy, Electron; D010316:Particle Size; D011658:Pulmonary Fibrosis; D017655:Silicon Compounds
chemical_list: D000395:Air Pollutants, Occupational; D017554:Carbon Compounds, Inorganic; D017655:Silicon Compounds; D002244:Carbon; C022088:silicon carbide