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
82
Low (3)
2
Low (1)
Not measured Not measured Not measured
Bridgend Park Street
Not measured 25
Low (1)
Not measured Not measured 11
Low (1)
Caerphilly Blackwood High Street
Not measured 51
Low (1)
Not measured Not measured 10
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured 4
Low (1)
5
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured 22
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 55
Low (1)
Not measured Not measured 6
Low (1)
Cardiff Castle Street
Not measured 81
Low (2)
Not measured 7
Low (1)
16
Low (1)
Cardiff Centre
98
Low (3)
73
Low (2)
2
Low (1)
6
Low (1)
8
Low (1)
Cardiff Newport Road
Not measured 67
Low (1)
Not measured Not measured 10
Low (1)
Chepstow A48
Not measured 72
Low (2)
Not measured 7
Low (1)
10
Low (1)
Cimla Road / Victoria Gardens
Not measured 42
Low (1)
Not measured Not measured Not measured
Cwmbran Crownbridge
102
Moderate (4)
24
Low (1)
Not measured Not measured 10
Low (1)
Hafod-yr-ynys Hill Roadside
Not measured 49
Low (1)
Not measured Not measured Not measured
Marchlyn Mawr
No Data 1
Low (1)
Not measured Not measured Not measured
Nantgarw Road
Not measured 24
Low (1)
Not measured Not measured Not measured
Narberth
91
Low (3)
3
Low (1)
1
Low (1)
3
Low (1)
4
Low (1)
Newport M4 Junction 25
62
Low (2)
85
Low (2)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 69
Low (2)
Not measured 4
Low (1)
6
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured 8
Low (1)
15
Low (1)
Port Talbot Little Warren
Not measured Not measured Not measured 6
Low (1)
8
Low (1)
Port Talbot Margam
90
Low (3)
24
Low (1)
65
Low (1)
6
Low (1)
17
Low (2)
Port Talbot Prince Street 2
Not measured Not measured Not measured 14
Low (2)
40
Low (3)
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 4
Low (1)
7
Low (1)
Rhondda Mountain Ash
Not measured 73
Low (2)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 79
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 51
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
82
Low (3)
28
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
69
Low (3)
105
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 60
Low (1)
Not measured Not measured Not measured
Swansea Morriston Roadside
78
Low (3)
37
Low (1)
Not measured 9
Low (1)
Not measured
Swansea Port Tennant Roadside
Not measured 54
Low (1)
Not measured 8
Low (1)
Not measured
Swansea Roadside
Not measured 58
Low (1)
Not measured 5
Low (1)
9
Low (1)
Swansea St Thomas DOAS
97
Low (3)
74
Low (2)
6
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 53
Low (1)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured No Data No Data
Wrexham
Not measured 33
Low (1)
2
Low (1)
5
Low (1)
8
Low (1)
Wrexham Chirk
Not measured 20
Low (1)
Not measured 3
Low (1)
11
Low (1)
Wrexham Chirk Community Hospital
Not measured 17
Low (1)
Not measured 2
Low (1)
10
Low (1)