| ID (ISN) del documento | 37940 |
| Número CIS |
82-948 |
| ISSN - Título de la serie |
0002-8894 - American Industrial Hygiene Association Journal |
| Año |
1982 |
| Número de serie |
|
| Autor(es) |
Janko M., Carlson P., Ellis K. |
| Título |
Analytical methods applied to Portland, Oregon, volcanic ash analysis |
| Información bibliográfica |
Feb. 1982, Vol.43, No.2, p.128-132. Illus. 15 ref. |
| Resumen |
In order to evaluate the possible exposure to free silica of crews cleaning up volcanic ash deposited by the 1980 eruptions of Mount St. Helens, the free silica content of the respirable dust portion of the ash was determined. Ash samples were pre-treated with phosphoric acid to remove silicate interferences and were analysed by x-ray diffraction for crystalline silicas. The residue after acid treatment was examined using optical methods, and the total crystalline free silica content was determined by the Talvitie colorimetric method. The colorimetric method was applied to occupational exposure samples of Portland-area maintenance personnel. Respirable dust exposure after 2 of the eruptions was in the range 0.02-0.48 and 0.03-0.36mg/m3, and the total crystalline silica content of the respirable dust fractions was 4.58-6.64%. Clean-up crews wore approved respirators. The combination of low-level exposure and respiratory protection reduced the possibility of silica-induced health problems. |
| Descriptores (primarios) |
construcción y reparación de carreteras; polvos respirables; sílice libre; vulcanismo |
| Descriptores (secundarios) |
polvos en suspensión aérea; colorimetría espectrofotométrica; Estados Unidos; descripción del procedimiento; valoración de la exposición; difractometría por rayos x; análisis de los polvos; sílice |
| Tipo de documento |
D - Artículos periódicos |
| Tema(s) |
Polvos, aerosoles
|
| Broad subject area(s) |
|
| Navegación por categoria(s) |
Natural phenomena
Road transportation
|
