Table
| 2013 | Change in per cent | ||
|---|---|---|---|
| Since 1990 | 2012 - 2013 | ||
| 1Does not include international sea and air traffic. | |||
| Nitrogen oxides (NOX) | 162 | -15.4 | -2.4 |
| Sulphur dioxide (SO2) | 17 | -67.9 | 0.6 |
| Ammonia (NH3) | 27 | 10.5 | -0.1 |
| Non-methane volatile organic compounds (NMVOC) | 139 | -52.7 | 1.1 |
| Carbon monoxide (CO) | 281 | -62.3 | -6.4 |