| Pollutant | 2006 | 2022 | 2023 | 2023 as against 2006 | 2023 as against 2022 |
|---|---|---|---|---|---|
| tonnes | change in percent | ||||
| Ammonia (NH3) | 710,481 | 578,509 | 570,912 | -19.6 | -1.3 |
| Sulphur oxide (SOx) | 608,314 | 256,425 | 227,015 | -62.7 | -11.5 |
| Nitrous oxide (NOx) | 2,064,272 | 1,206,004 | 1,120,433 | -45.7 | -7.1 |
| Non-methane volatile organic compounds (NMVOC) | 1,530,472 | 1,072,105 | 995,068 | -35.0 | -7.2 |
| Particulate matter 10 micrometre | 305,536 | 196,847 | 195,274 | -36.1 | -0.8 |
| Particulate matter 2.5 micrometre | 191,177 | 96,727 | 91,382 | -52.2 | -5.5 |
| Carbon monoxide (CO) | 3,938,265 | 2,651,295 | 2,496,926 | -36.6 | -5.8 |
As at 29 July 2025