Table
| 2013 | Change in per cent | ||
|---|---|---|---|
| Since 1990 | 2012 - 2013 | ||
| 1Does not include international sea and air traffic. | |||
| Nitrogen oxides (NOX) | 156 | -18.6 | -5.4 |
| Sulphur dioxide (SO2) | 17 | -67.4 | -1.6 |
| Ammonia (NH3) | 27 | 11.9 | 0.3 |
| Non-methane volatile organic compounds (NMVOC) | 135 | -53.7 | -0.8 |
| Carbon monoxide (CO) | 262 | -65.0 | -11.8 |