Table 2. Respirable crystalline silica concentrations - summary statistics.
| Description of Work | n | Geometric Mean (mg/m3) | Geometric Standard Deviation | Range (mg/m3) |
| Abrasive blasting at ground level | 7 | 0.22 | 1.59 | 0.12-0.43 |
| Abrasive blasting from an elevated platform | 9 | 0.13 | 2.25 | 0.04-0.41 |
| Helper | 8 | 0.06 | 2.08 | less than 0.02-0.12 |
