24 Hour Summary

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.

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 Hill
84
Low (3)
6
Low (1)
Not measured Not measured Not measured
Bridgend Park Street
Not measured 38
Low (1)
Not measured Not measured 15
Low (1)
Caerphilly Blackwood High Street
Not measured 28
Low (1)
Not measured Not measured 14
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured 5
Low (1)
14
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured 17
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 38
Low (1)
Not measured Not measured 10
Low (1)
Cardiff Castle Street
Not measured 79
Low (2)
Not measured 9
Low (1)
18
Low (2)
Cardiff Centre
87
Low (3)
27
Low (1)
1
Low (1)
9
Low (1)
14
Low (1)
Cardiff Newport Road
Not measured 50
Low (1)
Not measured Not measured 17
Low (2)
Chepstow A48
Not measured 24
Low (1)
Not measured 8
Low (1)
14
Low (1)
Cimla Road / Victoria Gardens
Not measured 38
Low (1)
Not measured Not measured Not measured
Cwmbran Crownbridge
No Data 28
Low (1)
Not measured Not measured 18
Low (2)
Hafod-yr-ynys Hill Roadside
Not measured 39
Low (1)
Not measured Not measured Not measured
Marchlyn Mawr
No Data 3
Low (1)
Not measured Not measured Not measured
Nantgarw Road
Not measured 18
Low (1)
Not measured Not measured Not measured
Narberth
74
Low (3)
3
Low (1)
1
Low (1)
5
Low (1)
7
Low (1)
Newport M4 Junction 25
74
Low (3)
59
Low (1)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 51
Low (1)
Not measured 8
Low (1)
13
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured 10
Low (1)
13
Low (1)
Port Talbot Little Warren
Not measured Not measured Not measured 11
Low (1)
13
Low (1)
Port Talbot Margam
67
Low (3)
32
Low (1)
38
Low (1)
11
Low (1)
20
Low (2)
Port Talbot Prince Street 2
Not measured Not measured Not measured 9
Low (1)
20
Low (2)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured No Data
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured 8
Low (1)
11
Low (1)
Rhondda Mountain Ash
Not measured 36
Low (1)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 32
Low (1)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 55
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
No Data No Data Not measured Not measured Not measured
Swansea Hafod DOAS
60
Low (2)
109
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured No Data Not measured Not measured Not measured
Swansea Morriston Roadside
No Data No Data Not measured No Data Not measured
Swansea Port Tennant Roadside
Not measured No Data Not measured No Data Not measured
Swansea Roadside
Not measured 52
Low (1)
Not measured 10
Low (1)
17
Low (2)
Swansea St Thomas DOAS
83
Low (3)
63
Low (1)
6
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured No Data Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured No Data No Data
Wrexham
Not measured 18
Low (1)
7
Low (1)
7
Low (1)
11
Low (1)
Wrexham Chirk
Not measured 19
Low (1)
Not measured 5
Low (1)
16
Low (1)
Wrexham Chirk Community Hospital
Not measured 17
Low (1)
Not measured 6
Low (1)
18
Low (2)