Estimated mean personal exposure concentrations associated with different groups of activity on days of differing background dustiness (μg/m3)
| Exposure to PM10 on days of differing dustiness | Inactive | Active indoors | Active outside | Outdoor play | Dusty occupations |
|---|---|---|---|---|---|
| Alert level | 1000 | 2000 | 3000 | 10000 | 10000 |
| Very high ash | 300 | 500 | 1000 | 5000 | 5000 |
| “Raised” ash | 100 | 150 | 200 | 500 | 500 |
| Low ash | 30 | 50 | 50 | 100 | 200 |