Endotoxin and 3-hydroxy fatty acid analysis of air and dust samples from an office butlding.
Hines-CJ; Petersen-M; Mendell-M; Milton-D; Larsson-L
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :31
Air and dust samples for endotoxin were collected on two floors of an office building during a double-blind particle intervention study. Sampling was performed to examine spatial and temporal variability of endotoxin in air over a period of weeks and to characterize endotoxin potency and lipopolysaccharide (LPS) content in carpet and chair dust. Each floor was divided into four subspaces. Air samples were collected on 0.4·mm polycarbonate filters at 3 L/min for 8 hours within and across weeks, with two measurements per subspace. Dust samples were collected from carpets and chairs 1 day per week for 3 weeks on glass fiber filters. All samples were analyzed for endotoxin with the Limulus assay. Dust samples were analyzed for LPS content by determination of 3-hydroxy fatty acids using GC-MS. The GM (GSD) for indoor air samples was 0.29 EU/m3, (1.6, n=96). The effect of subspace on the log of endotoxin air concentrations was highly significant (p<0.005, n=80). No effect of week, floor, or replicate was found. Mean endotoxin levels in carpet dust (59 EU/mg, n=12) and chair dust (38 EU/mg, n=10) were significantly different (p<0.001). Mean LPS for all dust samples was 72 +/- 9.6 pmoles/mg (n=22). Effects of dust source and floor on LPS levels depended on chain length. Carpet dust contained larger amounts of C10 and C12 LPS than chair dust (p<0.05, and <0.01, respectively); however, the amount of C16 LPS in chair dust was greater than in carpet dust (p<0.01). C16 LPS amounts were significantly different between the two floors (p<0.05). Endotoxin potency was correlated positively with C12 (r= -0.612) and negatively with C16 (r=0.673) LPS. These results indicate that location within floor was an important determinant of endotoxin exposure and that chemical analysis is useful for exploring microbial-related differences in dust composition.
Air-samples; Dust-particles; Dust-sampling; Endotoxins; Bacterial-dusts; Office-equipment; Dust-analysis; Microbial-test-systems; Chemical-analysis; Hydroxy-compounds; Fatty-acids; Gas-chromatography; Mass-spectrometry; Polysaccharides; Filters; Indoor-air-pollution; Indoor-environmental-quality
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia