The maximum pollutant concentrations measured during the last 24 hours across Wales are shown below. Summary graphs showing the last seven days are available for each pollutant in the left hand column of the table.
24 Hour Summary
| Site | 8 Hour mean Ozone µgm-3 |
Hourly mean Nitrogen dioxide µgm-3 |
Max 15 min mean Sulphur dioxide µgm-3 |
Running 24 Hour mean PM2.5 Particles µgm-3 |
Running 24 Hour mean PM10 Particles µgm-3 |
|---|---|---|---|---|---|
| Aston Expressway A494 Deeside |
Not measured | 34 Low (1) |
Not measured | Not measured | Not measured |
| Aston Hill |
48 Low (2) |
14 Low (1) |
Not measured | Not measured | Not measured |
| Caerphilly Islwyn Road Wattsville |
Not measured | 19 Low (1) |
Not measured | Not measured | Not measured |
| Caerphilly White Street |
Not measured | 31 Low (1) |
Not measured | Not measured | 24 Low (2) |
| Cardiff Castle Street |
Not measured | 33 Low (1) |
Not measured | 22 Low (2) |
31 Low (2) |
| Cardiff Centre |
35 Low (2) |
23 Low (1) |
1 Low (1) |
10 Low (1) |
12 Low (1) |
| Cardiff Newport Road |
Not measured | 30 Low (1) |
Not measured | Not measured | 14 Low (1) |
| Chepstow A48 |
Not measured | 34 Low (1) |
Not measured | 10 Low (1) |
12 Low (1) |
| Cimla Road / Victoria Gardens |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Cwmbran Crownbridge |
42 Low (2) |
11 Low (1) |
Not measured | Not measured | 19 Low (2) |
| Hafod-yr-ynys Hill Roadside |
Not measured | 45 Low (1) |
Not measured | Not measured | Not measured |
| Marchlyn Mawr |
94 Low (3) |
2 Low (1) |
Not measured | Not measured | Not measured |
| Nantgarw Road |
Not measured | 31 Low (1) |
Not measured | Not measured | Not measured |
| Narberth |
42 Low (2) |
19 Low (1) |
1 Low (1) |
18 Low (2) |
23 Low (2) |
| Newport M4 Junction 25 |
23 Low (1) |
21 Low (1) |
Not measured | Not measured | Not measured |
| Newport M4 Junction 25 West |
Not measured | 25 Low (1) |
Not measured | Not measured | Not measured |
| Newport St Julians Comp School |
Not measured | 20 Low (1) |
Not measured | 12 Low (2) |
16 Low (1) |
| Port Talbot Dyffryn School |
Not measured | Not measured | Not measured | 17 Low (2) |
20 Low (2) |
| Port Talbot Little Warren |
Not measured | Not measured | Not measured | 16 Low (2) |
19 Low (2) |
| Port Talbot M4 Junction 41 |
Not measured | 19 Low (1) |
Not measured | Not measured | Not measured |
| Port Talbot Margam |
50 Low (2) |
10 Low (1) |
2 Low (1) |
3 Low (1) |
6 Low (1) |
| Port Talbot Prince Street 2 |
Not measured | Not measured | Not measured | 17 Low (2) |
20 Low (2) |
| Rhondda Glyncoch Garth Avenue |
Not measured | Not measured | Not measured | 22 Low (2) |
26 Low (2) |
| Rhondda Mountain Ash |
Not measured | 15 Low (1) |
Not measured | Not measured | Not measured |
| Rhondda Pontypridd Gelliwastad Rd |
Not measured | 27 Low (1) |
Not measured | Not measured | Not measured |
| Rhondda-Cynon-Taf Broadway |
Not measured | 20 Low (1) |
Not measured | Not measured | Not measured |
| Rhondda-Cynon-Taf Pontypridd A470 |
Not measured | 26 Low (1) |
Not measured | Not measured | Not measured |
| Swansea Cwm Level Park |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Swansea Hafod DOAS |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Swansea Morfa Road NOX |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Swansea Morriston Roadside |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Swansea Port Tennant Roadside |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Swansea Roadside |
Not measured | 42 Low (1) |
Not measured | 8 Low (1) |
9 Low (1) |
| Swansea St Thomas DOAS |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Swansea Station Court High Street |
Not measured | Not measured | Not measured | Not measured | Not measured |
| Wrexham |
Not measured | 33 Low (1) |
3 Low (1) |
8 Low (1) |
11 Low (1) |
| Wrexham A483 |
Not measured | 30 Low (1) |
Not measured | Not measured | Not measured |
| Wrexham Chirk |
Not measured | 28 Low (1) |
Not measured | 14 Low (2) |
28 Low (2) |
| Wrexham Chirk Community Hospital |
Not measured | 12 Low (1) |
Not measured | 3 Low (1) |
5 Low (1) |