Biopersistence of nonfibrous mineral particles in the respiratory tracts of subjects following occupational exposure.

Abstract

Transmission electron microscopy analysis (TEMA) was used to analyze the bronchoalveolar lavage fluid (BALF) of 262 subjects occupationally exposed (OE) to nonfibrous mineral particles (NFMP) and 42 controls not occupationally exposed to mineral dusts. OE subjects were divided into three groups according to the lapse of time since last exposure: <1 year (El), >1 year and <10 years (E2), .10 years (E3). The total BALF mineral particle concentration was significantly higher in OE patients than in controls and was closely related to the time lapse since last exposure to NFMP (median values for OE, 7.7x105 particles/ml; El, 9x105 particles/ml; E2, 5x105 particles/ml; E3, 4.3x105 particles/ml; controls, 2x105 particles/ml). No statistical difference was observed for age and smoking habits between OE and control subjects. Concentrations of crystalline silica and metals (exogenous iron, aluminum, metallic alloys and other metals) were significantly higher in OE subjects than in controls, and even though these mineral concentrations decreased with increasing time since last occupational exposure, they still remained higher in the E3 group than in controls. Crystalline silica and metals were thus identified as biopersistent NFMP in the human lung using BALF ATEM method. This method is a useful tool in assessing occupational exposure to NFMP, even when a long period has elapsed since last exposure, and may be used in studying etiology of some respiratory diseases. -Environ Health Perspect 1 02(Suppl 5): 269-275 (1994)

Mineralogical analysis of the respiratory tract in aluminium oxide-exposed workers

“…Alternatively, our data are also consistent with various forms of aluminium oxides (such as alumina trihydroxide Al(OH) 3 or crystallized alumina Al 2 O 3 , either α or γ form). As the fibre parameters are similar to those reported by GILKS and CHURG [14], we consider that the most probable fibre composition was The concentrations of aluminium nonfibrous particles were also high in these five subjects, largely above mean or median values reported for aluminium-containing NFMP in BAL fluid samples or lung tissue samples of controls in previous series analysed in the same laboratory [18,19]. The mean value of aluminium-containing NFMP in BAL fluid was 5.6×10 3 particles·mL -1 (range 0-1.28×10 4 particles·mL -1 ) in the first series of 42 controls [19].…”

“…As the fibre parameters are similar to those reported by GILKS and CHURG [14], we consider that the most probable fibre composition was The concentrations of aluminium nonfibrous particles were also high in these five subjects, largely above mean or median values reported for aluminium-containing NFMP in BAL fluid samples or lung tissue samples of controls in previous series analysed in the same laboratory [18,19]. The mean value of aluminium-containing NFMP in BAL fluid was 5.6×10 3 particles·mL -1 (range 0-1.28×10 4 particles·mL -1 ) in the first series of 42 controls [19]. Mean values of aluminium-containing NFMP in BAL fluid and lung tissue were 1×10 4 particles·g -1 dry lung tissue in the second series of 10 patients without any known recent occupational exposure to mineral particles [18].…”

“…Fibrous and nonfibrous mineral particles (NFMP) may be counted by conventional light microscopy (quantification of asbestos bodies) and analytical transmission electron microscopy (ATEM) [18][19][20]. This evaluation of the retention of mineral particles in the lung has been shown to provide invaluable assistance in some respiratory diseases, mainly asbestos-related diseases, allowing the establishment of a dose-response relationship between lung cancer or parenchymal fibrosis and the number of asbestos bodies in BAL fluid or lung tissue [21,22].…”

The utility of electron microscopy in detecting asbestos fibers and particles in BALF in diffuse lung diseases

“…A few reports have shown the relationship between the mineral components of particles in BALF and occupational exposure to mineral dusts. Parion et al showed significantly increased levels of iron in the BALF of 205 occupationally-exposed patients in comparison to 41 patients without occupational exposure, and Bernstein et al also showed that iron was significantly increased in the BALF of 46 dental technicians with lung diseases in comparison to 41 white-collar workers with lung diseases [ 22 , 23 ]. Our results showing an increase of elemental iron detected by EM in BALF in the exposure-positive group are consistent with these previous studies, and the detection of iron may be useful in screening for occupation-related lung diseases.…”