Air
quality index - UK
Air Quality
Index
UK central government Department DEFRA (Department for the Environment,
Farming and Rural Affairs) currently uses an air quality index to inform
members of the public about the air quality in the UK.
The air quality index is used to simplify the measurements
obtained through the monitoring station in to four main bands, with an index of
1-10, with 10 being the poorest air quality.
The four main bands in respect to air quality are Low, Moderate, High
and Very High. These bands are then further clarified by providing useful
health information associated with the different categories of air quality, as
shown in the table below:
|
Air Pollution Bandings and Index and the Impact on the
Health of People who are Sensitive to Air Pollution
|
|
Banding
|
Index
|
Health
Descriptor
|
|
Low
|
1
|
Effects
are unlikely to be noticed even by individuals who know they are sensitive to
air pollutants
|
|
2
|
|
3
|
|
Moderate
|
4
|
Mild
effects, unlikely to require action, may be noticed amongst sensitive
individuals.
|
|
5
|
|
6
|
|
High
|
7
|
Significant
effects may be noticed by sensitive individuals and action to avoid or reduce
these effects may be needed (e.g. reducing exposure by spending less time in
polluted areas outdoors). Asthmatics will find that their 'reliever' inhaler
is likely to reverse the effects on the lung.
|
|
8
|
|
9
|
|
Very High
|
10
|
The
effects on sensitive individuals described for 'High' levels of pollution may
worsen.
|
Air Quality index and Monitoring Data
The Air Quality
Index is the information that is given to members of the public, however this
index needs to be based on air pollution monitoring data gathered for the
different pollutants that are currently measured under the requirements of the
Air Quality Regulations 2000 ( as amended).
This was the legislation issued to adopt the requirements of the
European Daughter Directives on Air Quality.
The table below
shows how the monitoring data is converted into the Air Quality index above
|
Boundaries Between Index Points for Each Pollutant
|
|
Band
|
Index
|
Ozone
|
Nitrogen Dioxide
|
Sulphur Dioxide
|
Carbon Monoxide
|
PM10 Particles
|
|
8 hourly running mean or hourly
mean*
|
hourly mean
|
15 minute mean
|
8 hour running mean
|
24 hour running mean
|
|
µgm-3
|
ppb
|
µgm-3
|
ppb
|
µgm-3
|
ppb
|
mgm-3
|
ppm
|
µgm-3
|
|
Low
|
|
|
1
|
0-32
|
0-16
|
0-95
|
0-49
|
0-88
|
0-32
|
0-3.8
|
0.0-3.2
|
0-16
|
|
2
|
33-66
|
17-32
|
96-190
|
50-99
|
89-176
|
33-66
|
3.9-7.6
|
3.3-6.6
|
17-32
|
|
3
|
67-99
|
33-49
|
191-286
|
100-149
|
177-265
|
67-99
|
7.7-11.5
|
6.7-9.9
|
33-49
|
|
Moderate
|
|
|
4
|
100-126
|
50-62
|
287-381
|
150-199
|
266-354
|
100-132
|
11.6-13.4
|
10.0-11.5
|
50-57
|
|
5
|
127-152
|
63-76
|
382-476
|
200-249
|
355-442
|
133-166
|
13.5-15.4
|
11.6-13.2
|
58-66
|
|
6
|
153-179
|
77-89
|
478-572
|
250-299
|
443-531
|
167-199
|
15.5-17.3
|
13.3-14.9
|
67-74
|
|
High
|
|
|
7
|
180-239
|
90-119
|
573-635
|
300-332
|
532-708
|
200-266
|
17.4-19.2
|
15.0-16.5
|
75-82
|
|
8
|
240-299
|
120-149
|
363-700
|
333-366
|
709-886
|
267-332
|
19.3-21.2
|
16.6-18.2
|
83-91
|
|
9
|
300-359
|
150-179
|
701-763
|
367-399
|
887-1063
|
333-399
|
21.3-23.1
|
18.3-19.9
|
92-99
|
|
Very High
|
|
|
10
|
360 or more
|
180 or more
|
764 or more
|
400 or more
|
1064 or more
|
400 or more
|
23.2 or more
|
20 or more
|
100 or more
|
|
* For ozone, the maximum of the 8
hourly and hourly mean is used to calculate the index value.
|
Example Birmingham and Midlands Area
The information
below is a specific example of the index for the Birmingham and West Midlands area of the UK.
|
Pollutant levels
recorded for the hour up to 11am
Mon Oct 18th
|
|
|
N/M means that
the pollutant is not measured at that site
N/A means that no data were recorded for the period
|
|
|
Birmingham
Urban area
|
|
SITE
|
Hourly Mean
Ozone
(ppb)
|
Hourly Mean
Nitrogen dioxide
(ppb)
|
max 15min mean
Sulphur dioxide
(ppb)
|
8 Hourly Mean
Carbon monoxide
(ppm)
|
24 Hour mean
PM10
Particles
(µgm-3)
|
|
Birmingham
Centre
|
18 (2 Low)
|
18 (1 Low)
|
10 (1 Low)
|
0.1 (1 Low)
|
10 (1 Low)
|
|
Birmingham Tyburn
|
14 (1 Low)
|
N/A
|
11 (1 Low)
|
0.3 (1 Low)
|
13 (1 Low)
|
|
Sandwell West Bromwich
|
10 (1 Low)
|
28 (1 Low)
|
10 (1 Low)
|
1.1 (1 Low)
|
N/M
|
|
Walsall Alumwell
|
N/M
|
30 (1 Low)
|
N/M
|
N/M
|
N/M
|
|
Walsall Willenhall
|
N/M
|
13 (1 Low)
|
N/M
|
N/M
|
N/M
|
|
Wolverhampton Centre
|
8 (1 Low)
|
4 (1 Low)
|
3 (1 Low)
|
0.3 (1 Low)
|
10 (1 Low
|
|
|
|
|
|
|
|
Website
UK National Air Quality Archive – www.airquality.co.uk |