Table
| 2017 | Change in percent | ||
|---|---|---|---|
| Since 1990 | 2016 - 2017 | ||
| 1Does not include international sea and air traffic. | |||
| Nitrogen oxides (NOX) | 149 | -24.4 | -4.5 |
| Sulphur dioxide (SO2) | 16 | -68.0 | -2.5 |
| Ammonia (NH3) | 28 | 5.9 | 0.4 |
| Non-methane volatile organic compounds (NMVOC) | 153 | -52.1 | -3.6 |
| Carbon monoxide (CO) | 438 | -50.2 | 1.1 |