| Value | Category | Cases | |
|---|---|---|---|
| 1 | Industrial activities | 90 |
3%
|
| 2 | Waste burning | 145 |
4.9%
|
| 3 | Transportation | 40 |
1.3%
|
| 4 | Construction | 2 |
0.1%
|
| 5 | others | 11 |
0.4%
|
| 6 | furnaces | 16 |
0.5%
|
| Sysmiss | 2667 |