Mean (range) personal exposures to respirable dust and cristobalite measured using cylcone samplers during June 1997 (average concentrations measured over 4–8 hour shifts)
| Concentration (μg/m3) | |||
|---|---|---|---|
| Occupation | Respirable dust | Cristobalite | Number of samples |
| Gardener/handyman | 825 (817–833) | 41 (<5–82) | 2 |
| Roadworkers | >20000 (77–71000) | Not measured | 6 |
| Police at road checkpoint | 373 (45–778) | 51 (<5–76) | 3 |
| Housekeeper | 442 | 30 | 1 |
| Waiter | 96 | 11 | 1 |
| Office worker | 173 | 18 | 1 |
| Driving | 357 (144–830) | 32 (<5–105) | 5 |