Air Pollution in the UK 2009

www.defra.gov.uk
Air Pollution in the UK 2009
Edition A: Summary of the UK’s Annual
Report to the EU Commission under
Directives 2008/50/EC and 2004/107/ECAir Pollution in the UK 2009- Edition A
ii
A report prepared by AEA for Defra and the Devolved Administrations.
Title Air Pollution in the UK 2009 – Edition A, A Summary of the UK’s Annual
Report to the EU Commission under Directives 2008/50/EC and
2004/107/EC
Authors AEA Technology: Agnieszka Griffin, Andrew Kent, Alison Loader, Carlos
Martinez, John Stedman, Ken Stevenson, Keith Vincent, Paul Willis,
Rachel Yardley
Defra: Emily Connolly and Clare Bayley
Published by the Department for Environment, Food and Rural Affairs,
September 2010
Department for Environment, Food and Rural Affairs
Nobel House
17 Smith Square
London SW1P 3JR
Telephone 020 7238 6000
Website: www.defra.gov.uk
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Email: licensing@cabinet-office.x.gsi.gov.ukAir Pollution in the UK 2009 – Edition A
iii
Executive Summary
The UK is required to report air quality data on an annual basis under the following European
Directives:
 The Council Directive on ambient air quality and cleaner air for Europe (2008/50/EC)
 The Fourth Daughter Directive 2004/107/EC under the Air Quality Framework
Directive (1996/62/EC)
This report summarises the UK’s 2009 submission on air quality to the EU Commission,
presenting air quality modelling data and measurements from national air pollution
monitoring networks. These data are produced on behalf of Defra (the Department for
Environment, Food and Rural Affairs) and the Devolved Administrations of Scotland, Wales
and Northern Ireland.
The pollutants covered in this report are:
 Sulphur dioxide (SO2)
 Nitrogen oxides: (NOx) comprising
NO and NO2
 PM10 and PM2.5 particles
 Benzene
 Carbon Monoxide (CO)
 Heavy Metals
 Polycyclic aromatic hydrocarbons
(PAH)
 Ozone (O3)
The report provides background information on the pollutants, their sources and effects, the UK’s
statutory monitoring networks, the UK’s modelling methodology and detail on the exceedences
reported in 2009, with an overview of trends.
The 2009 results can be summarised as follows.
 No exceedences of the SO2 limit value were reported in 2009 or in recent years.
 The UK exceeded the limit value plus margin of tolerance for hourly mean nitrogen dioxide
in two zones, and annual mean nitrogen dioxide in 40 zones (out of a total of 43
zones).This is similar to the numbers of exceedences both measured and modelled in
previous years.
 Only one zone was reported as exceeding the 24-hour limit value for PM10 during the year,
after subtraction of the contribution from natural sources. This is the same as last year.
 Exceedences were reported for the long term ozone objective for human health in 39
zones, and exceedences were reported for the long term ozone objective for vegetation in
10 of the 15 non-agglomeration zones where it applies.
 Two exceedences of the target values for nickel were reported in 2009, as was the case in
2008.
 Six exceedences of the target values were reported for benzo[a]pyrene as in 2008.
Copies of previous annual submissions can be found on the Commission website:
http://cdr.eionet.europa.eu/gb/eu/annualair. For more information on air quality in the UK visit
the Defra website at www.defra.gov.uk/environment/quality/air/index.htm and the UK Air Quality
websites at www.airquality.co.uk, www.scottishairquality.co.uk, www.welshairquality.co.uk and
www.airqualityni.co.uk.Air Pollution in the UK 2009- Edition A
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Table of contents
1 Introduction 3
2 The Evidence Base 4
2.1 Pollutants of Concern 4
2.2 Current UK Air Quality Monitoring 7
2.3 Modelling 9
3 Assessment of Compliance 11
3.1 Definition of Zones 11
3.2 Air Quality Assessment for 2009 13
3.3 Comparison with Previous Years 20
4 Where to find more information 25Air Pollution in the UK 2009 – Edition A
3
1 Introduction
European Directives on ambient air quality require the UK to undertake air quality assessment, and
to report the findings to the Commission on an annual basis. Historically this has been under:
 The Air Quality Framework Directive (1996/62/EC)
 The Daughter Directives (DD) (1st DD -1999/30/EC, 2nd DD -2000/69/EC, 3rd DD -
2002/3/EC and 4th DD- 2004/107/EC).
In June 2008, a new Directive came into force:  the Council Directive on ambient air quality and
cleaner air for Europe (2008/50/EC) – known as the “Air Quality Directive”
1
 This Directive .
consolidates the first three Daughter Directives, and was transposed into the Regulations in
England, Scotland, Wales and Northern Ireland in June 2010. The 4
th
Daughter Directive
2
remains
in force.
The UK has statutory monitoring networks in place to meet the requirements of these Directives,
with air quality modelling used to supplement the monitored data.
In 2009 the UK undertook the annual air quality assessment in accordance with the Air Quality
Directive and the 4
th
Daughter Directive (4
th
DD). The results were submitted to the European
Commission in the form of a standard questionnaire which each Member State must complete.
Previous annual submissions can be found on the Commission website:
http://cdr.eionet.europa.eu/gb/eu/annualair.
This report provides a summary of the UK’s 2009 annual report to the Commission, based upon
measurements and modelling results. The 2009 Air Pollution in the UK report follows a different
structure to recent years’ publications. This year two editions of the report will be published:
 Edition A, published in September 2010, has the primary objective of accompanying the
UK’s submission of 2009 air quality data via a Questionnaire to the European Commission
and making it more public facing. This report focuses on the statutory monitoring, and
supplementary modelling, undertaken in the UK.
 Edition B will be published in December 2010, to provide information to a wider group of
stakeholders and members of the public. This report will look in more detail at other
monitoring undertaken for research purposes and will include more detailed analysis of air
pollution in the UK.
This report (Edition A of Air Pollution in the UK 2009) will:
 Review the evidence base – the pollutants of concern and where and how air pollution is
measured and modelled in the UK (Section 2).
 Provide a summary of the UK air quality in relation to two European Directives (Section 3):
o Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on
ambient air quality and cleaner air for Europe
o Directive 2004/107/EC of the European Parliament and of the Council of 15 December
2004 relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic
hydrocarbons in ambient air – the 4
th
Daughter Directive.
This summary also compares the 2009 data with recent years and provides an assessment
of the data trends.
 Provide information on where and how to find out more about air pollution emissions, levels
and effects in the UK (Section 4).
Links to the suite of EC Directives on ambient air quality are provided on Defra’s web pages at
http://www.defra.gov.uk/environment/quality/air/airquality/eu-int/eu-directives/airqualdirectives/index.htm .Air Pollution in the UK 2009- Edition A
4
2 The Evidence Base
2.1 Pollutants of Concern
This section describes the sources and effects of the pollutants being assessed in relation to the Air
Quality Directive and 4
th
Daughter Directive.
Sulphur Dioxide
Sulphur dioxide (SO2) is an acidic gas, formed by the oxidation of sulphur impurities in fuels during
combustion processes. A very high proportion (approximately 85%) of UK SO2 emissions originate
from power stations and industrial sources.
SO2 can cause constriction of the airways of the lung. This effect is particularly likely to occur in
people suffering from asthma and chronic lung disease. It is a precursor to secondary PM and
therefore contributes to the ill-health effects caused by PM10 and PM2.5. There is potential for
damage to ecosystems at high levels, including degradation of chlorophyll, reduced photosynthesis,
raised respiration rates and changes in protein metabolism. Deposition of pollution derived from
SO2 emissions can contribute to acidification of soils and waters and subsequent loss of
biodiversity, often at locations far removed from the original emissions.
As the use of coal for domestic heating has decreased over the last 30-40 years, SO2  emissions
and atmospheric concentrations have decreased. In recent decades, SO2 concentrations have
remained high in some mining regions in England, also in parts of Northern Ireland. However
recent years have seen a decrease in SO2 concentrations here as well.
Nitrogen Oxides
A mixture of nitrogen oxides NO and NO2, collectively referred to as NOx, are emitted from many
combustion processes. In the UK, the main sources of NOx are power generation and road
transport. Motor vehicles make the largest contribution to long-term ground level concentrations in
urban areas, and highest NOx levels in UK cities generally occur at kerbside locations in urban
areas. In the presence of sunlight, nitrogen oxides can react with Volatile Organic Compounds
(VOCs) to produce photochemical pollutants including ozone. Nitrogen dioxide can be further
oxidised in air to acid gases such as nitric acid, which contribute to the production of acid rain.
NO2 is associated with adverse effects on human health. At high levels NO2 causes inflammation of
the airways. Long term exposure may affect lung function and respiratory symptoms. NO2 also
enhances the response to allergens in sensitive individuals. High levels of NOX can have an adverse
effect on vegetation, including leaf or needle damage and reduced growth. Deposition of pollutants
derived from NOX emissions contribute to acidification and/or eutrophication of sensitive habitats
leading to loss of biodiversity, often at locations far removed from the original emissions. NOX also
contributes to the formation of secondary particles and ground level ozone, both of which are
associated with ill-health effects. Ozone also damages vegetation.
Particulate Matter
Particulate Matter (PM) is a generic term referring to suspended particles consisting of a wide range
of sizes and chemical compositions. Particles are produced from a variety of natural and man-made
sources. Natural sources include sea salt, wind-blown soil, Saharan dust, forest fires and volcanic
activity. Man-made sources include incomplete combustion processes (e.g. coal and diesel smoke),
industry and construction activity.
Particles may be either directly emitted into the atmosphere (primary particles) or formed there by
chemical reactions (secondary particles). Sulphate and nitrate aerosols are secondary particles;
these can often transported over national or continental distances.
Particle size is usually expressed in terms of its aerodynamic diameter. Two fine size fractions of
particulate matter are measured in UK national monitoring networks: PM10 and PM2.5. These are the
mass fractions of particles collected by a sampler with a 50% inlet cut-off at aerodynamic diameter
10 μm and 2.5 μm respectively. Fine particles are the main focus in air quality monitoring, as fine Air Pollution in the UK 2009 – Edition A
5
particulate matter can penetrate deep into the airways, carrying surface-absorbed harmful
compounds into the lungs, increasing the risk of health effects.
Both short-term and long-term exposure to ambient levels of PM are consistently associated with
respiratory and cardiovascular illness and mortality as well as other ill-health effects. The
associations are believed to be causal. It is not currently possible to discern a threshold
concentration below which there are no effects on the whole population’s health.
Carbon Monoxide
Carbon monoxide (CO) is a colourless, odourless and tasteless gas. Carbon monoxide in urban
areas results almost entirely from vehicle emissions. Ambient concentrations are therefore closely
linked to road transport emissions. In urban areas, concentrations are highest at the kerbside and
decrease rapidly with increasing distance from the road. Highest levels are observed in the city
centres, near the kerb of congested roads.
At worst-case ambient levels (in congested streets, car-parks or tunnels), exposure may reduce
the oxygen-carrying capacity of the blood and impair oxygen delivery to the brain and other
organs, particularly affecting adults with angina and diseases of the coronary arteries.
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. Ambient benzene
concentrations result primarily from road transport and the domestic combustion of wood fuel.
Benzene is naturally broken down by chemical reactions in the atmosphere over a period up to
several days; thus outdoor benzene concentrations tend to reflect road networks and traffic density
patterns.
Benzene is a recognised human carcinogen which attacks genetic material and, as such, no
absolutely safe level can be specified in ambient air. Studies in workers exposed to high levels have
shown an excessive risk of leukaemia.
Ozone
Ozone (O3) is a form of oxygen, with three atoms per molecule instead of the usual two. Ozone in
the stratosphere (the “ozone layer”) helps protect life on earth against harmful levels of UV
radiation: however, at ground level it is a harmful pollutant.
Ozone is not emitted directly into the atmosphere in any significant quantity, but is formed from a
complex series of chemical reactions involving other “precursor” pollutants - volatile organic
compounds (VOCs) and presence of nitrogen oxides (NOx) - in the presence of sunlight.
The reactions producing ozone occur in air containing these NOx and VOC precursors as it moves
downwind; ozone formation can occur over a timescale of a few hours to several days. As a result,
highest concentrations of ozone usually occur in rural areas, and often a long distance from the
source of the precursor emissions.
Exposure to high concentrations may cause irritation to eyes and nose. Very high levels can
damage airways leading to inflammatory reactions. Ozone reduces lung function and increases
incidence of respiratory symptoms, respiratory hospital admissions and mortality. Ground level
ozone can also cause damage to many plant species leading to loss of yield and quality of crops,
damage to forests and impacts on biodiversity.
Lead
The majority of lead emissions arise from industry, in particular non-ferrous metal smelters.
Exposure to high levels in air may result in toxic biochemical effects which have adverse effects on
the kidneys, gastrointestinal tract, the joints and reproductive systems, and acute or chronic
damage to the nervous system. Lead can affect intellectual development in young children.
Heavy Metals
Nickel is found in ambient air as a result of releases from oil and coal combustion, nickel metal
refining, sewage sludge incineration, manufacturing facilities, and other sources. It may cause
damage to the kidneys, inhibit reproductive ability, and result in respiratory problems.Air Pollution in the UK 2009- Edition A
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Arsenic is emitted into the atmosphere as arsenic trioxide in the form of particulate matter. The
primary source of arsenic emissions to the air in the UK is the combustion of coal and other fossil
fuels, also industrial processes which use arsenic. Exposure to arsenic dust causes respiratory
irritation and it is believed to be a carcinogen.
Inhalation of cadmium present in airborne particulate matter results in a build-up of cadmium in
the kidneys that can cause kidney disease. Exposure to cadmium is also likely to increase the risk
of lung cancer in humans.
Mercury is released to the air by human activities, such as coal burning, use of mercury in
industrial processes, and the release of mercury in dental fillings from crematoria. High levels of
mercury in the bloodstream of unborn babies and infants may impede the development of the
nervous system.
Benzo[a]pyrene
Benzo[a]pyrene is used as a “marker” for a group of chemical compounds known as polycyclic
aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are a large group of persistent
bio-accumulative organic compounds with toxic or human carcinogenic effects; they are produced
from a wide range of industrial, chemical and combustion processes.
The main sources of ambient B[a]P are fossil fuel combustion, vehicle exhaust and the production
of asphalt. (A major source of human exposure is also cigarette smoke). Studies of occupational
exposure to PAHs have shown an increased incidence of tumours of the lung, skin and possibly
bladder and other sites. Lung cancer is most obviously linked to exposure to PAHs through inhaled
air. Individual PAHs vary in their ability to induce tumours in animals or humans.
2.2 Assessment of Air Quality in the UK
The evidence base for the annual questionnaire and assessment of compliance is based on a
combination of information from the UK national monitoring networks and the results of modelling
assessments. Considerably more monitoring sites would be required across the whole of the UK if
monitoring data were to be used as the sole source of information. The use of models has the
added benefits of enabling air quality to be assessed at locations without monitoring sites and
providing additional information on source apportionment and projections required for the
development and implementation of air quality plans.
Annex III of the Air Quality Directive provides information on where ambient air quality should be
assessed and this applies to both measurements and modelling. The Annex is very prescriptive and
identifies how many monitors are needed and where they should be located.
Modelling is undertaken using a national model known as the Pollution Climate Mapping (PCM)
model. The PCM models have been designed to assess compliance with the limit values at locations
defined within the directives. It should be noted that at a local level, Local Authorities undertake air
quality assessment for a different purpose and following different methodologies. Local Air Quality
Monitoring (LAQM) modelling will usually output contour plots showing dispersion away from the
source, on a fine resolution grid. National modelling focuses on concentrations at four metres away
from selected road links. The level of detail and resolution of LAQM modelling is therefore much
greater in order to focus on local exposure and hotspots. See Section 2.4 for more details on
modelling.
Local Air Quality Management aims to identify and assess hot-spots within the Authority’s boundary
with focus on locations where members of the public are likely to be regularly present and are
likely to be exposed for a period of time appropriate to the averaging period of the objective. The
criteria for locations requiring assessment are different to those modelled at national level. For
example, junctions are explicitly required to be assessed under LAQM if in the Updating and
Screening Assessment, new exceedences of objectives are identified, whereas Directive
2008/50/EC excludes junctions from assessment at national level. Both of these are in contrast to
the approach of national modelling which is to assess only at the locations defined within the
Directives.Air Pollution in the UK 2009 – Edition A
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Local authorities undertake air quality monitoring for the purpose of local air quality management,
in particular of nitrogen dioxide and PM10. Examples of differences between the monitoring
undertaken by local authorities and by Defra and the Devolved Administrations for compliance
purposes are as follows:
 The monitoring undertaken for reporting to the Commission is undertaken in accordance
with the assessment procedures set out in the Air Quality Directive, 2008/50/EC.  In
contrast, there are no restrictions on where local authority monitors can be located, and
these monitors are often placed in hot spot locations which are not required to be assessed
under the Air Quality Directive.
 The QA/QC procedures applied to the data are not to the same standard as those on the
national compliance monitoring networks.
 The Air Quality Directive requires either reference method equipment or equivalent to be
used for compliance purposes. The equipment used by local authorities may not meet these
standards and therefore data quality might be affected.
2.3 Current UK Air Quality Monitoring
There are nearly 400 national air quality monitoring sites across the UK, each with different
objectives, scope and coverage. This section provides a brief description of those used to monitor
compliance with the Air Quality Directive and the 4
th
Daughter Directive. A summary of the UK
national networks is provided in Table 2.1, and the measurement techniques are summarised in
Table 2.2.
Table 2.1 The UK Air Quality Monitoring Networks
Network Statutory
or
Research
Pollutants  Number of Sites
The Automatic Urban and
Rural Network (AURN)
Statutory CO, NOx, SO2, PM10, PM2.5. 132 (97 urban, 27
rural, 8 London)
Ammonia Network Research Gaseous ammonia (NH3),
particulate aerosol
ammonium (NH4
+
.(
83
Eutrophying and Acidifying
Pollutants
Research NO2, gaseous nitric acid,
SO2, hydrochloric acid,
aerosol nitrate, sulphate and
chloride.
38
Toxic Organic Micropollutants
(TOMPS)
Research Toxic organic compounds 7
Polycyclic Aromatic
Hydrocarbons (PAH)
Statutory PAH 31
Particle concentrations and
numbers
Research Total particle number,
concentration, size distribution
4
Black Carbon Research Black Carbon 20
UK Heavy Metals Monitoring
Network
Statutory Metals As, Cd, Cr, Cu, Fe,
Hg, Mn, Ni, Pb, Pt, V, Zn
24
Non automatic Hydrocarbon
Network
Statutory Benzene 36
Automatic Hydrocarbon
Network
Statutory Range of VOCs 4
2.3.1 The Automatic Urban and Rural Network (AURN)
The AURN is currently the largest automatic monitoring network in the UK and forms the bulk of
the UK’s statutory compliance monitoring evidence base.  Data from the AURN are available on the
Air Quality Archive at www.airquality.co.uk.Air Pollution in the UK 2009- Edition A
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The techniques used for monitoring within the AURN are the reference methods of measurement
defined in the relevant EU Directives for the gaseous pollutants. For particulate matter the AURN
uses methods which have demonstrated equivalence to the reference method, but which (unlike
the reference method) allow continuous on-line monitoring. Details are in Table 2.2.
Table 2.2 AURN Measurement Techniques
Pollutant  CEN standard/ref method Details
O3 EN 14625:2005 “Ambient air quality –
standard method for the measurement
of the concentration of ozone by
ultraviolet photometry”
3
UV absorption: ozone absorbs UV light.
The absorption of UV by sampled air is
used to calculate the ozone
concentration.
NO2/NOx EN 14211:2005 “Ambient air quality -
Standard method for the measurement
of the concentration of nitrogen dioxide
and nitrogen monoxide by
Chemiluminescence”
4
Chemiluminescent: this method
measures the energy emitted when nitric
oxide (NO) is reacted with ozone (O3) in
an evacuated chamber to form
chemiluminescent nitrogen dioxide
(NO2).
SO2 EN 14212:2005 “Ambient air quality –
Standard method for the measurement
of the concentration of sulphur dioxide
by UV fluorescence”
5
UV fluorescence: SO2 molecules are
excited to higher energy states by UV
radiation. These excited molecules then
release this energy as light (fluorescent
radiation). The intensity of this can be
used to calculate the concentration of
SO2 in sampled air.
CO EN 14625:2005 “Ambient air quality -
Standard method for the measurement
of the concentration of carbon monoxide
by infra red absorption”
6
IR absorption: Carbon monoxide
strongly absorbs infrared radiation of
wavelength 4.5 to 4.9 µm. A reference
detection system is used to alternately
measure absorption due to CO in the
sampled air stream and absorption by
interfering species. An infrared detector
gives a signal proportional to the CO
concentration.
PM10 and
PM2.5
EN 12341:1999 “Air quality.
Determination of the PM10 fraction of
suspended particulate matter. Reference
method and field test procedure to
demonstrate reference equivalence of
measurement methods.”
7
EN 14907:2005 “Ambient air quality -
Standard gravimetric measurement
method for the determination of the
PM2.5 mass fraction of suspended
particulate matter”
8
The AURN uses three equivalent
methods:
the Filter Dynamic Measurement
System (FDMS), which determines
particulate concentration by
continuously weighing particles
deposited on a filter:  the betaattenuation monitor (BAM) which
measures the attenuation of beta rays
passing through a paper filter on which
particulate matter from sampled air has
been collected, and Partisol – an
equivalent  gravimetric sampler that
collects daily samples onto a filter for
subsequent weighing.
2.3.2 Heavy Metals Network
The UK Heavy Metals Network forms the basis of the UK’s compliance monitoring for:
 The Air Quality Directive (for lead)
 The 4
th
Daughter Directive (for arsenic, cadmium and nickel).
This network monitors a range of metallic elements at urban, industrial and rural sites, using a
method equivalent to the CEN standard method
9
 In 2009, it comprised 24 sites, all of which .
monitored As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Pt, V and Zn.   Additionally, measurements of
ambient vapour phase mercury concentrations are made at 13 sites.Air Pollution in the UK 2009 – Edition A
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2.3.3 Non-automatic Hydrocarbon Network
In this network of 36 sites, ambient concentrations of benzene are measured by the CEN standard
method
10
, which involves pumping air across an adsorption tube to trap the compound, which is
later analysed in a laboratory. This network monitors compliance with the CAFÉ Directive.
2.3.4 Automatic Hydrocarbon Network
Automatic hourly measurements of a range of hydrocarbon species are made using automated
pumped sampling with in situ gas chromatography, which is an EU reference method
11
, at five sites
in the UK. These sites monitor benzene, which is covered by the CAFÉ Directive. This network also
provides data on ozone precursors (compounds that lead to the formation of ozone), which must
also be reported to the European Commission.
Two monitoring sites, at Harwell in Oxfordshire and Auchencorth Moss in Lothian, are also part of
the European EMEP programme, an international co-operative programme for monitoring and
evaluation of the long-range transmissions of air pollutants in Europe.
2.3.5 PAH Monitoring Network
The PAH Network monitors compliance with the 4
th
Daughter Directive, which includes a target
value of 1 ngm-3
for the annual mean concentration of benzo[a]pyrene as a representative PAH, to
be achieved by 2012. This network uses the CEN reference method
12
 Ambient air is sampled .
through glass fibre filters and polyurethane foam pads, which capture the PAH compounds for later
analysis in a laboratory. During 2009, there were 31 sites in this network.
2.4 Modelling
2.4.1 Why Do Modelling?
The UK’s monitoring programmes are supplemented by air quality modelling. There are several
benefits of using modelling to complement the monitoring data gathered across the UK national
monitoring networks:
 The reduced need for fixed continuous monitoring – freeing up resources to be spent
elsewhere such as on developing policy to improve air quality.
 Coverage of the whole UK rather than specific locations where there is a monitoring site. A
monitoring site might not fully represent the wider region in which it is located.
 Provides a framework within which to assess different air quality scenarios – for example
projecting concentrations forward to assess levels in future years, representing potential
changes to emissions in order to assess the impact of policy initiatives on air quality.
2.4.2 How the Models Work
The modelling method varies between pollutants. Methodology is explained in separate reports
13,14,15
(the latest versions of these can be found on the Air Quality Archive
16
 .(
Air quality modelling in the UK consists of two aspects:
 Background concentrations – on a 1x1km resolution, representing ambient air quality
concentrations at background locations.
 Roadside concentrations – concentrations at the roadside of urban major road links
throughout the UK (i.e. motorways and major A-roads). There are approximately 9,000 of
these road links.Air Pollution in the UK 2009- Edition A
10
Roadside concentrations are not modelled for SO2, ozone, benzo[a]pyrene (BaP) and heavy metals
which do not have significant roadside sources.
The models have been designed to assess compliance at locations defined by the Directives as
relevant for air quality assessment.
2.4.3 Background Air Quality
The 1x1 km background maps are made up of several components which are modelled separately
and then added together to make the final grid. These individual components (supplemented by
some additional components for various pollutants) are:
 Large point sources (e.g.  power stations, steel works, oil refineries)
 Small point sources (e.g. boilers in town halls, schools or hospitals, crematoria)
 Distant sources (characterised by the rural background concentration)
 Local area sources (e.g. road traffic, domestic and commercial combustion, agriculture).
In order to ensure that these ambient concentrations from area sources are representative of the
real world situation, they are calibrated against measurements taken from the national networks
(including the AURN). After the calibration has been completed the large points, small points,
distant sources and calibrated area source components are added together to provide the final
background map.
2.4.4 Roadside Air Quality
Roadside concentrations are estimated by using a roadside increment model which attempts to
estimate the contribution from road traffic sources and adds this on top of the modelled
background concentrations discussed above.
For each of the road links that are modelled, there are emissions estimates from the NAEI for each
pollutant and road traffic count. A roadside increment is calculated for road links with a roadside
monitoring station on them by taking the modelled background concentration (from the 1x1 km
modelled maps) link away from the relevant measured roadside concentration.  The emission for
the road link is scaled according to annual average daily traffic flow for that link and then this is
compared against the roadside increment to establish a relationship. This relationship is then used
to scale the link emission for different ranges of traffic flow and added to the modelled background
concentration to calculate an estimated roadside concentration.  Air Pollution in the UK 2009 – Edition A
11
3 Assessment of Compliance
3.1 Definition of Zones
The UK has been divided into 43 zones for air quality assessment. There are 28 agglomeration
zones (large urban areas) and 15 non-agglomeration zones. Form 2 of the Questionnaire contains
details of these including type, area, and population (from the 2001 census). Each zone is assigned
an identification code: these are listed in Table 3.1 and illustrated in Figure 3.1.
Table 3.1 UK zones and agglomerations for ambient air quality reporting 2009
Zone Zone code Ag or non-ag*
Greater London Urban Area UK0001 ag
West Midlands Urban Area UK0002 ag
Greater Manchester Urban Area UK0003 ag
West Yorkshire Urban Area UK0004 ag
Tyneside UK0005 ag
Liverpool Urban Area UK0006 ag
Sheffield Urban Area UK0007 ag
Nottingham Urban Area UK0008 ag
Bristol Urban Area UK0009 ag
Brighton/Worthing/Littlehampton UK0010 ag
Leicester Urban Area UK0011 ag
Portsmouth Urban Area UK0012 ag
Teesside Urban Area UK0013 ag
The Potteries UK0014 ag
Bournemouth Urban Area UK0015 ag
Reading/Wokingham Urban Area UK0016 ag
Coventry/Bedworth UK0017 ag
Kingston upon Hull UK0018 ag
Southampton Urban Area UK0019 ag
Birkenhead Urban Area UK0020 ag
Southend Urban Area UK0021 ag
Blackpool Urban Area UK0022 ag
Preston Urban Area UK0023 ag
Glasgow Urban Area UK0024 ag
Edinburgh Urban Area UK0025 ag
Cardiff Urban Area UK0026 ag
Swansea Urban Area UK0027 ag
Belfast Metropolitan Urban Area UK0028 ag
Eastern UK0029 non-ag
South West UK0030 non-ag
South East UK0031 non-ag
East Midlands UK0032 non-ag
North West & Merseyside UK0033 non-ag
Yorkshire & Humberside UK0034 non-ag
West Midlands UK0035 non-ag
North East UK0036 non-ag
Central Scotland UK0037 non-ag
North East Scotland UK0038 non-ag
Highland UK0039 non-ag
Scottish Borders UK0040 non-ag
South Wales UK0041 non-ag
North Wales UK0042 non-ag
Northern Ireland UK0043 non-ag
Total
ag = agglomeration zone,  non-ag = non-agglomeration zoneAir Pollution in the UK 2009- Edition A
12
Figure 3.1 UK zones and agglomerations for ambient air quality reporting 2009
Agglomeration zones (red)
Non-agglomeration zones (blue/green)
© Crown copyright. All rights reserved Defra, Licence number 100022861 [2010]Air Pollution in the UK 2009 – Edition A
13
3.2 Air Quality Assessment for 2009
As explained in section 2, the air quality assessment for each pollutant is derived from a
combination of measured and modelled concentrations. Where both measurements and
model results are available the assessment of compliance for each zone is based on the
higher concentration of the two.
The results of the air quality assessment submitted to the European Commission are
summarised in the tables below.  The tables have been completed as follows:
 Where all measurements were within the relevant limit values, (or limit values
with margins of tolerance where applicable) in 2009, the table shows this as “OK”.
 Where compliance was determined by modelling, this is shown as “OK (m)”.
 Where locations were identified as exceeding a limit value, or a limit value plus
margin of tolerance where applicable, this is identified as “ >MOT” or “>LV” as
applicable.
 Where an exceedence was determined by modelling, this is indicated by (m), as
above.
Zones that complied with the relevant limit values, targets or long-term objectives are
shaded blue, while those that did not are shaded red.
A similar approach has also been used to compare concentrations with target values (TV)
and long term objectives (LTO). “n/a” means that an assessment is not relevant for this
zone, such as for the vegetation limit value in agglomeration zones.
3.2.1 Assessment under Directive 2008/50/EC on
Ambient Air Quality and Cleaner Air for Europe
Sulphur dioxide: the results of the air quality assessment for sulphur dioxide are
presented in Form 8a of the Questionnaire.
In 2009, all zones and agglomerations within the UK complied with the limit values for 1-
hour mean and 24-hour mean SO2 concentration, set for protection of human health.
All non-agglomeration zones within the UK also complied with the limit values for annual
mean and winter mean SO2 concentration, set for protection of ecosystems. (These are not
applicable to built-up areas).
Nitrogen dioxide: the results of the air quality assessment for nitrogen dioxide for each
zone are presented in Form 8b of the Questionnaire, and summarised in Table 3.2.
Two agglomeration zones - Greater London Urban Area (UK0001) and Glasgow
Urban Area (UK0024) had locations which exceeded the 1-hour limit value plus margin
of tolerance (220 µg m-3
) on more than the permitted number of occasions during 2009.
The majority of zones and agglomerations in the UK had locations with measured or
modelled annual mean NO2 concentrations higher than the annual mean limit value plus
margin of tolerance (42 µg m-3
). This was the case in 40 zones of the 43 zones. Only the
following three zones met the annual mean limit value in 2009:
 Blackpool Urban Area (UK0022)
 Highland (UK0039)
 Scottish Borders (UK0040)
All others exceeded the annual mean limit value.Air Pollution in the UK 2009- Edition A
14
All non-agglomeration zones within the UK also complied with the limit value for annual
mean NO2 concentration, set for protection of vegetation.
Particulate matter: the results of the air quality assessment for PM10 and PM2.5 for each
zone are presented in Form 8c and 9c of the Questionnaire respectively, and summarised
in Table 3.3.
Three zones had locations where measured or modelled PM10 concentrations exceeded the
24-hour mean limit value of 50 µg m-3
on more than the permitted number of days:
Greater London Urban Area (UK0001)
Southampton Urban Area (UK0019)
Eastern (zone) (UK0029)
The Directive requires Member States to quantify the contribution to PM10 from natural
sources, and subtract this. After subtraction of the contribution from natural sources, one
modelled exceedence of the 24-hour limit value remained in one zone (Greater London
Urban Area, UK0001)
All zones and agglomerations complied with the annual mean limit value of 40 µg m-3
for
PM10.
Annual mean concentrations of PM2.5 were below the target value in all zones and
agglomerations.
Carbon monoxide, benzene and lead: the results of the air quality assessment for lead,
benzene and CO are presented in Form 8d, 8e and 8f of the Questionnaire respectively. All
zones or agglomerations were compliant with the limit values for these three pollutants in
2009.
Ozone: the results of the air quality assessment for ozone for each zone are presented in
Form 9a of the Questionnaire.
All zones and agglomerations were compliant with the two target values, which are based
on the maximum daily 8-hour mean and on the AOT40 statistic
1
.
There are also two long-term objectives, one for human health, and one (only applicable in
the non-agglomeration zones) for vegetation. 39 zones and agglomerations were above
the long-term objective (LTO) for health, and 10 of the 15 non-agglomeration zones were
above the long-term objective for vegetation. This is illustrated in Table 3.4 below with
compliant zones shaded blue and non-compliant ones shaded red. Air Pollution in the UK 2009 – Edition A
15
Table 3.2 Results of air quality assessment for nitrogen dioxide in 2009
Zone Zone code
NO2 LV for
health (annual
mean)
NOx LV for
vegetation
(annual mean)
Greater London Urban Area UK0001 > MOT n/a
West Midlands Urban Area UK0002 > MOT n/a
Greater Manchester Urban Area UK0003 > MOT n/a
West Yorkshire Urban Area UK0004 > MOT n/a
Tyneside UK0005 > MOT (m) n/a
Liverpool Urban Area UK0006 > MOT (m) n/a
Sheffield Urban Area UK0007 > MOT (m) n/a
Nottingham Urban Area UK0008 > MOT (m) n/a
Bristol Urban Area UK0009 > MOT n/a
Brighton/Worthing/Littlehampton UK0010 > MOT (m) n/a
Leicester Urban Area UK0011 > MOT (m) n/a
Portsmouth Urban Area UK0012 > MOT (m) n/a
Teesside Urban Area UK0013 > MOT (m) n/a
The Potteries UK0014 > MOT (m) n/a
Bournemouth Urban Area UK0015 > MOT (m) n/a
Reading/Wokingham Urban Area UK0016 > MOT (m) n/a
Coventry/Bedworth UK0017 > MOT (m) n/a
Kingston upon Hull UK0018 > MOT (m) n/a
Southampton Urban Area UK0019 > MOT (m) n/a
Birkenhead Urban Area UK0020 > MOT (m) n/a
Southend Urban Area UK0021 > MOT (m) n/a
Blackpool Urban Area UK0022 OK (m) n/a
Preston Urban Area UK0023 > MOT (m) n/a
Glasgow Urban Area UK0024 > MOT n/a
Edinburgh Urban Area UK0025 > MOT (m) n/a
Cardiff Urban Area UK0026 > MOT (m) n/a
Swansea Urban Area UK0027 > MOT (m) n/a
Belfast Urban Area UK0028 > MOT (m) n/a
Eastern UK0029 > MOT OK
South West UK0030 > MOT OK (m)
South East UK0031 > MOT OK
East Midlands UK0032 > MOT (m) OK
North West & Merseyside UK0033 > MOT (m) OK (m)
Yorkshire & Humberside UK0034 > MOT (m) OK (m)
West Midlands UK0035 > MOT (m) OK (m)
North East UK0036 > MOT (m) OK (m)
Central Scotland UK0037 > MOT (m) OK (m)
North East Scotland UK0038 > MOT (m) OK (m)
Highland UK0039 OK OK (m)
Scottish Borders UK0040 OK OK (m)
South Wales UK0041 > MOT (m) OK
North Wales UK0042 > MOT (m) OK (m)
Northern Ireland UK0043 > MOT (m) OK (m)Air Pollution in the UK 2009- Edition A
16
Table 3.3 Results of air quality assessment for PM10 and PM2.5 in 2009 prior
to subtraction of natural sources.
Zone Zone code
PM10 LV (24hr
mean)
PM10 LV (annual
mean)
PM2.5 Target
value (annual
mean)
Greater London Urban Area UK0001 > LV OK OK
West Midlands Urban Area UK0002 OK OK OK
Greater Manchester Urban Area UK0003 OK OK OK
West Yorkshire Urban Area UK0004 OK OK OK
Tyneside UK0005 OK OK OK
Liverpool Urban Area UK0006 OK OK OK
Sheffield Urban Area UK0007 OK (m) OK (m) OK
Nottingham Urban Area UK0008 OK (m) OK (m) OK
Bristol Urban Area UK0009 OK OK OK
Brighton/Worthing/Littlehampton UK0010 OK (m) OK (m) OK
Leicester Urban Area UK0011 OK OK OK (m)
Portsmouth Urban Area UK0012 OK (m) OK (m) OK
Teesside Urban Area UK0013 OK (m) OK (m) OK (m)
The Potteries UK0014 OK OK OK
Bournemouth Urban Area UK0015 OK (m) OK (m) OK
Reading/Wokingham Urban Area UK0016 OK OK OK
Coventry/Bedworth UK0017 OK (m) OK (m) OK
Kingston upon Hull UK0018 OK OK OK
Southampton Urban Area UK0019 > LV (m) OK OK
Birkenhead Urban Area UK0020 OK (m) OK (m) OK
Southend Urban Area UK0021 OK (m) OK (m) OK
Blackpool Urban Area UK0022 OK (m) OK (m) OK
Preston Urban Area UK0023 OK (m) OK (m) OK
Glasgow Urban Area UK0024 OK OK OK
Edinburgh Urban Area UK0025 OK (m) OK (m) OK
Cardiff Urban Area UK0026 OK OK OK
Swansea Urban Area UK0027 OK OK OK
Belfast Urban Area UK0028 OK OK OK
Eastern UK0029 > LV (m) OK OK
South West UK0030 OK OK OK (m)
South East UK0031 OK OK OK
East Midlands UK0032 OK OK OK
North West & Merseyside UK0033 OK OK OK
Yorkshire & Humberside UK0034 OK OK OK
West Midlands UK0035 OK OK OK
North East UK0036 OK OK OK
Central Scotland UK0037 OK OK OK
North East Scotland UK0038 OK OK OK (m)
Highland UK0039 OK OK OK
Scottish Borders UK0040 OK (m) OK (m) OK (m)
South Wales UK0041 OK OK OK
North Wales UK0042 OK OK OK (m)
Northern Ireland UK0043 OK OK OK (m)
Note: Following subtraction of natural sources, only UK001, Greater London Urban Area
remained non-compliant with the 24 hour mean limit value for PM10. Air Pollution in the UK 2009 – Edition A
17
Table 3.4 Results of air quality assessment for ozone in 2009
Zone Zone code
O3 LTO for health (8hr
mean)
O3 LTO for health
(annual mean)
Greater London Urban Area UK0001 Meets TV, >LTO OK
West Midlands Urban Area UK0002 Meets TV, >LTO OK
Greater Manchester Urban Area UK0003 Meets TV, >LTO (m) OK
West Yorkshire Urban Area UK0004 Meets TV, >LTO (m) OK
Tyneside UK0005 Meets TV, >LTO (m) OK
Liverpool Urban Area UK0006 Meets TV, >LTO OK
Sheffield Urban Area UK0007 Meets TV, >LTO (m) OK
Nottingham Urban Area UK0008 Meets TV, >LTO (m) OK
Bristol Urban Area UK0009 Meets TV, >LTO OK
Brighton/Worthing/Littlehampton UK0010 Meets TV, >LTO Meets TV, >LTO
Leicester Urban Area UK0011 Meets TV, >LTO OK
Portsmouth Urban Area UK0012 Meets TV, >LTO OK
Teesside Urban Area UK0013 Meets TV, >LTO (m) OK
The Potteries UK0014 Meets TV, >LTO OK
Bournemouth Urban Area UK0015 Meets TV, >LTO OK
Reading/Wokingham Urban Area UK0016 Meets TV, >LTO Meets TV, >LTO
Coventry/Bedworth UK0017 Meets TV, >LTO OK
Kingston upon Hull UK0018 Meets TV, >LTO (m) OK
Southampton Urban Area UK0019 Meets TV, >LTO (m) OK
Birkenhead Urban Area UK0020 Meets TV, >LTO OK
Southend Urban Area UK0021 Meets TV, >LTO Meets TV, >LTO
Blackpool Urban Area UK0022 Meets TV, >LTO OK
Preston Urban Area UK0023 Meets TV, >LTO OK
Glasgow Urban Area UK0024 OK OK
Edinburgh Urban Area UK0025 OK OK
Cardiff Urban Area UK0026 Meets TV, >LTO OK
Swansea Urban Area UK0027 Meets TV, >LTO OK
Belfast Urban Area UK0028 OK OK
Eastern UK0029 Meets TV, >LTO Meets TV, >LTO
South West UK0030 Meets TV, >LTO Meets TV, >LTO
South East UK0031 Meets TV, >LTO Meets TV, >LTO (m)
East Midlands UK0032 Meets TV, >LTO Meets TV, >LTO
North West & Merseyside UK0033 Meets TV, >LTO OK
Yorkshire & Humberside UK0034 Meets TV, >LTO (m) OK
West Midlands UK0035 Meets TV, >LTO Meets TV, >LTO (m)
North East UK0036 Meets TV, >LTO (m) OK (m)
Central Scotland UK0037 Meets TV, >LTO (m) OK
North East Scotland UK0038 Meets TV, >LTO (m) OK
Highland UK0039 OK OK
Scottish Borders UK0040 Meets TV, >LTO (m) OK
South Wales UK0041 Meets TV, >LTO Meets TV, >LTO
North Wales UK0042 Meets TV, >LTO Meets TV, >LTO
Northern Ireland UK0043 Meets TV, >LTO (m) OK
Measured exceedences of limit values, margins of tolerance, target values, long term
objectives, information and alert thresholds are also listed within the annual air quality
assessment questionnaire. Summary statistics for the exceedences identified are provided
in Table 3.5 – Table 3.10.
Table 3.5 Exceedences of the NO2 limit value plus MOT for health (1 hour
mean)
Site name
Zone
code
Number of 1-hour
exceedences of MOT
Number of 1-hour
exceedences of LV
Maximum 1-hour
concentration (g m
-3
(
Glasgow Centre UK0024 43 48 701
Glasgow Kerbside UK0024 32 57 384
London Marylebone Road UK0001 312 486 332Air Pollution in the UK 2009- Edition A
18
Table 3.6 Exceedences of the NO2 limit value plus MOT for health (annual
mean)
Site name Zone code
Annual mean
concentration  (g m
-3
(
Bath Roadside UK0030 65
Birmingham Tyburn Roadside UK0002 47
Bristol Old Market UK0009 63
Bury Roadside UK0003 72
Glasgow City Chambers UK0024 46
Glasgow Kerbside UK0024 78
Haringey Roadside UK0001 43
Leeds Headingley Kerbside UK0004 48
London Bloomsbury UK0001 54
London Cromwell Road 2 UK0001 72
London Hillingdon UK0001 54
London Marylebone Road UK0001 107
London Westminster UK0001 44
Oxford Centre Roadside UK0031 50
Sandy Roadside UK0029 46
Tower Hamlets Roadside UK0001 61
Table 3.7 Exceedences of the PM10 limit value (24 hour mean)
Site name Zone code
Number of 24-hour
exceedences of LV
Maximum 24-hour
concentration (g m
-3
(
London Marylebone Road PARTISOL UK0001 36 88
Note: Number of exceedences reduced to 25 after subtraction of the contribution from
natural sources but a modelled exceedence of the 24 hour mean limit value remains in this
zone after subtraction of the contribution from natural sources.  
Table 3.8 Exceedences of the ozone information threshold value
Site name Zone code
Number of 1-hour
exceedences of alert threshold
Maximum 1-hour
concentration (g m
-3
(
Brighton Preston Park UK0010 1 184
Sibton UK0029 3 200
Southend-on-Sea UK0021 2 210
St Osyth UK0029 5 258
Table 3.9 Exceedences of the ozone alert threshold value
Site name Zone code
Number of 1-hour exceedences of
information threshold
Maximum 1-hour
concentration (g m
-3
(
St Osyth UK0029 2 258Air Pollution in the UK 2009 – Edition A
19
Table 3.10 Exceedences of the ozone long term objective for health protection
Site name Zone code
Number of days with
exceedences
Maximum 8-hour
concentration (g m
-3
(
Aston Hill UK0042 5 136
Birmingham Tyburn UK0002 2 150
Birmingham Tyburn Roadside UK0002 1 132
Blackpool Marton UK0022 1 137
Bottesford UK0032 1 121
Bournemouth UK0015 3 131
Brighton Preston Park UK0010 2 171
Bristol St Paul's UK0009 5 128
Cardiff Centre UK0026 2 125
Charlton Mackrell UK0030 3 122
Coventry Memorial Park UK0017 3 150
Cwmbran UK0041 6 131
Glazebury UK0033 1 124
Harwell UK0031 3 157
Ladybower UK0032 2 128
Leamington Spa UK0035 2 148
Leicester Centre UK0011 1 138
Leominster UK0035 2 131
Liverpool Speke UK0006 1 125
London Haringey UK0001 1 151
London Harlington UK0001 1 136
London N. Kensington UK0001 1 128
London Teddington UK0001 3 154
Lullington Heath UK0031 2 145
Market Harborough UK0032 1 128
Narberth UK0041 4 134
Northampton UK0032 5 163
Port Talbot Margam UK0027 1 125
Portsmouth UK0012 2 161
Preston UK0023 1 124
Reading New Town UK0016 5 164
Rochester Stoke UK0031 1 124
Sandwell West Bromwich UK0002 4 157
Sibton UK0029 2 170
Southend-on-Sea UK0021 2 152
St Osyth UK0029 2 188
Stoke-on-Trent Centre UK0014 1 122
Thurrock UK0029 1 134
Weybourne UK0029 12 144
Wicken Fen UK0029 3 147
Wigan Centre UK0033 1 124
Wirral Tranmere UK0020 1 133
Yarner Wood UK0030 6 133
3.2.2 Assessment under the Fourth Daughter Directive
2004/107/EC
The results of the air quality assessment for arsenic, cadmium, nickel and benzo(a)pyrene
for each zone are presented in Form 9b of the Questionnaire, and illustrated in Table 3.11.
All zones and agglomerations met the target values for arsenic and cadmium. Two zones
exceeded the target value for nickel and below in all other zones. Concentrations of B[a]P
were above the target value in six zones and below in all other zones.Air Pollution in the UK 2009- Edition A
20
Table 3.11 Results of air quality assessment for As, Cd, Ni and benzo(a)pyrene
in 2009
Zone Zone code As TV Cd TV Ni TV B(a)P TV
Greater London Urban Area UK0001 OK OK OK OK (m)
West Midlands Urban Area UK0002 OK OK OK OK
Greater Manchester Urban Area UK0003 OK OK OK OK
West Yorkshire Urban Area UK0004 OK (m) OK (m) OK (m) OK
Tyneside UK0005 OK (m) OK (m) OK (m) OK
Liverpool Urban Area UK0006 OK (m) OK (m) OK (m) OK
Sheffield Urban Area UK0007 OK OK OK OK (m)
Nottingham Urban Area UK0008 OK (m) OK (m) OK (m) OK (m)
Bristol Urban Area UK0009 OK OK OK OK (m)
Brighton/Worthing/Littlehampton UK0010 OK (m) OK (m) OK (m) OK
Leicester Urban Area UK0011 OK (m) OK (m) OK (m) OK (m)
Portsmouth Urban Area UK0012 OK (m) OK (m) OK (m) OK (m)
Teesside Urban Area UK0013 OK OK OK > TV (m)
The Potteries UK0014 OK (m) OK (m) OK (m) OK (m)
Bournemouth Urban Area UK0015 OK (m) OK (m) OK (m) OK (m)
Reading/Wokingham Urban Area UK0016 OK (m) OK (m) OK (m) OK (m)
Coventry/Bedworth UK0017 OK (m) OK (m) OK (m) OK (m)
Kingston upon Hull UK0018 OK (m) OK (m) OK (m) OK (m)
Southampton Urban Area UK0019 OK (m) OK (m) OK (m) OK (m)
Birkenhead Urban Area UK0020 OK (m) OK (m) OK (m) OK (m)
Southend Urban Area UK0021 OK (m) OK (m) OK (m) OK (m)
Blackpool Urban Area UK0022 OK (m) OK (m) OK (m) OK (m)
Preston Urban Area UK0023 OK (m) OK (m) OK (m) OK (m)
Glasgow Urban Area UK0024 OK OK OK OK
Edinburgh Urban Area UK0025 OK (m) OK (m) OK (m) OK
Cardiff Urban Area UK0026 OK OK OK OK
Swansea Urban Area UK0027 OK OK > TV (m) > TV (m)
Belfast Urban Area UK0028 OK OK OK OK
Eastern UK0029 OK OK OK OK
South West UK0030 OK OK OK OK (m)
South East UK0031 OK OK OK OK
East Midlands UK0032 OK OK OK OK
North West & Merseyside UK0033 OK OK OK OK
Yorkshire & Humberside UK0034 OK OK OK > TV
West Midlands UK0035 OK (m) OK (m) OK (m) OK (m)
North East UK0036 OK OK OK > TV (m)
Central Scotland UK0037 OK OK OK OK
North East Scotland UK0038 OK OK OK OK (m)
Highland UK0039 OK (m) OK (m) OK (m) OK
Scottish Borders UK0040 OK OK OK OK (m)
South Wales UK0041 OK OK > TV (m) > TV (m)
North Wales UK0042 OK (m) OK (m) OK (m) OK (m)
Northern Ireland UK0043 OK (m) OK (m) OK (m) > TV
3.3 Comparison with Previous Years
Tables 3.12 to 3.17 summarise the results of the air quality assessment for 2009 and
provide a comparison with the results of the assessments carried out in previous years.  Air Pollution in the UK 2009 – Edition A
21
Table 3.12  Exceedences of limit values plus margins of tolerance for the Air Quality Directive
Pollutant  Averaging
time
2009 2008 2007 2006 2005 2004 2003 2002 2001
SO2 1-hour n/a n/a n/a n/a n/a 1 zone
modelled
(Eastern)
1 zone
modelled
(Eastern)
none none
SO2 24-hour
1
n/a n/a n/a n/a n/a none 1 zone
modelled
(Eastern)
none 1 zone
measured
(Belfast
Urban
Area)
SO2 annual
2
n/a n/a n/a n/a n/a n/a n/a n/a n/a
SO2 winter
2
n/a n/a n/a n/a n/a n/a n/a n/a n/a
NO2 1-hour
3
2 zones
measured
(London,
Glasgow)
2 zones
measured
(London,
Glasgow)
1 zone
measured
(Greater
London
Urban Area)
1 zone
measured
(Greater
London
Urban Area)
1 zone
measured
(Greater
London
Urban Area)
1 zone
measured
(Greater
London
Urban Area)
1 zone
measured
(Greater
London
Urban Area)
none none
NO2 annual 40 zones (9
measured +
31 modelled)
40 zones (7
measured +
33 modelled)
39 zones (6
measured +
33 modelled)
38 zones (6
measured +
32 modelled)
35 zones (6
measured +
29 modelled)
34 zones (6
measured +
28 modelled)
35 zones (5
measured +
30 modelled)
19 Zones
(5
measured
+ 14
modelled)
21 Zones
(4
measured
+ 17
modelled)
NOx annual
2
n/a n/a n/a n/a n/a n/a n/a n/a n/a
PM10 24-hour
4
(Stage 1)
n/a n/a n/a n/a n/a 19 zones (1
measured +
18 modelled)
18 zones (2
measured +
16 modelled)
1 zone
modelled
(Greater
London
Urban
Area)
1 zone
modelled
(Greater
London
Urban
Area)
PM10 annual
(Stage 1)
n/a n/a n/a n/a n/a 1 zone
modelled
(Greater
London
Urban Area)
10 zones (1
measured +
9 modelled)
1 zone
modelled
(Greater
London
Urban
Area)
1 zone
modelled
(Greater
London
Urban
Area)
Lead annual n/a  n/a n/a n/a n/a none none none noneAir Pollution in the UK 2009- Edition A
22
Pollutant  Averaging
time
2009 2008 2007 2006 2005 2004 2003 2002 2001
Benzene annual none none none none none none none not
assessed
not
assessed
CO 8-hour n/a n/a n/a n/a n/a none none not
assessed
not
assessed
1
No MOT defined, LV + MOT = LV
2
Applies to vegetation and ecosystem areas only. No MOT defined, LVs are already in force
3
No modelling for 1-hour LV
Table 3.13 Exceedences of limit values for the Air Quality Directive
Pollutant
Averaging time
2009 2008 2007 2006 2005 2004 2003 2002 2001
SO2 1-hour none none none 1 zone
modelled
(Eastern)
1 zone
modelled
(Eastern)
1 zone
modelled
(Eastern)
1 zone
modelled
(Eastern)
none none
SO2 24-hour
1
none none none 1 zone
modelled
(Eastern)
1 zone
modelled
(Eastern)
none 1 zone
modelled
(Eastern)
none 1 Zone
measured
(Belfast
Urban
Area)
SO2 Annual
2
none none none none  none  none  none  none none
SO2 Winter
2
none none none none  none  none  none  none not
assessed
NO2 1-hour
3
2 zones
measured
(London,
Glasgow)
3 zones
measured
(London,
Glasgow, NE
Scotland)
2 zones
measured
(London,
Glasgow)
1 zone
measured
(Greater
London
Urban Area)
2 zones
measured
(London,
Bristol)
1 zone
measured
(Greater
London
Urban Area)
3 zones
measured
(London,
Glasgow,
South East)
1 zone
measured
(Glasgow
Urban
Area)
4 zones
measured
NO2 Annual 40 zones (9
measured + 31
modelled)
40 zones (10
measured + 30
modelled)
41 zones
(8
measured
+ 33
modelled)
39 zones (7
measured +
32 modelled)
38 zones (8
measured +
30 modelled)
39 zones (9
measured +
30 modelled)
42 zones (10
measured +
32 modelled)
36 zones
(6
measured
+ 30
modelled)
38 zones
(6
measured
+ 32
modelled)
NOx Annual
2
none none none none none none none none NoneAir Pollution in the UK 2009 – Edition A
23
Pollutant
Averaging time
2009 2008 2007 2006 2005 2004 2003 2002 2001
PM10 24-hour
(Stage 1)
3 zones (1
measured + 2
modelled) 1
zone modelled
after
subtraction of
natural
contribution
2 zones (1
measured + 1
modelled) 1 zone
measured after
subtraction of
natural
contribution
6 zones (3
measured
+ 3
modelled)
30 zones (5
measured +
25 modelled)
29 zones (3
measured +
26 modelled)
27 zones (2
measured +
25 modelled)
33 zones (10
measured +
23 modelled)
18 zones
(1
measured
+ 17
modelled)
26 zones
(5
measured
+ 21
modelled)
PM10 annual
(Stage 1)
none none 1 zone
measured
(Greater
London
Urban
Area)
2 zones (1
measured +
1 modelled)
4 zones (1
measured +
3 modelled)
2 zones (1
measured,
London + 1
modelled,
West
Midlands
Urban Area)
15 zones (1
measured +
14 modelled)
2 zones
(Greater
London
Urban Area
measured,
Eastern
modelled)
2 zones
(London
measured,
Manchester
modelled)
Lead Annual none none none none none none none none None
Benzene Annual none none none 1 zone
modelled
(Yorkshire &
Humberside)
2 zones
modelled
(Yorkshire &
Humberside,
Central
Scotland)
none 1 zone
modelled
(Greater
London
Urban Area)
not
assessed
not
assessed
CO 8-hour none none none none none none none not
assessed
not
assessed
1
No MOT defined, LV + MOT = LV
2
Applies to vegetation and ecosystem areas only. No MOT defined, LVs are already in force
3
No modelling for 1-hour LV
Table 3.14 Exceedences of Air Quality Directive Target Values
Pollutant  Averaging time 2009 2008 2007 2006 2005 2004
O3 8-hour none 1 zone measured
(Eastern)
none none  none none
O3 AOT40 none none none none  none none Air Pollution in the UK 2009- Edition A
24
Table 3.15 Exceedences of Air Quality Directive Long Term Objectives
Pollutant  Averaging
time
2009 2008 2007 2006 2005 2004
O3 8-hour 39 zones (25
measured + 14
modelled)
43 zones (35
measured + 8
modelled)
41 zones (24
measured + 17
modelled)
43 zones (41
measured + 2
modelled)
37 zones (22
measured + 15
modelled)
43 zones (36
measured + 7
modelled)
O3 AOT40 10 zones (8
measured + 2
modelled)
41 zones (25
measured + 16
modelled)
3 zones (1 measured
+ 2 modelled)
41 zones (32
measured + 9
modelled)
16 zones (9
measured + 7
modelled)
7 zones (5
measured + 2
modelled)
Table 3.16 Exceedences of 4
th
Daughter Directive Target Values
Pollutant  Averaging
time
2009 2008 2007
As Annual none none none
Cd Annual none none none
Ni Annual 2 zones modelled (Swansea, S Wales) 2 zones modelled (Swansea, S Wales,
measured at non-network site, so
reported as m)
1 zone (Swansea Urban area, measured
but low data capture, so reported as m)
BaP Annual 6 zones, (2 zones measured Yorkshire &
Humberside, N Ireland + 4 zones
modelled Teesside, Swansea, North
East, S Wales)
6 zones, (3 zones measured Yorkshire &
Humberside, Teesside, N Ireland + 3
zones modelled Swansea, S Wales,
Belfast)
1 zone measured (Yorkshire &
Humberside)
Table 3.17 Exceedences of Air Quality Directive Target Value for PM2.5
Pollutant  Averaging
time
2009
PM2.5 Annual noneAir Pollution in the UK 2009 – Edition A
25
4 Where to find more information
This section provides details of sources of further information on the UK’s air quality, including
media and web-based resources.
The Defra air quality information web resource at
http://www.defra.gov.uk/environment/airquality/index.htm contains details of what the UK is doing
to tackle air pollution, and the science and research programmes in place.
As shown in previous sections, the UK’s air monitoring programmes produce very large amounts of
data. The UK’s Air Quality Archive at www.airquality.co.uk and Air Quality Information
Service are the key tools enabling the widest access and use of air quality information in the UK.
The main functions of these systems are:
 To inform citizens about the quality of the outdoor air we all breathe
 To provide information to Local Government, for the purpose of planning and Local Air
Quality Management
 To provide public warnings in the event of extreme conditions, as required by a number of
EC Directives and Decisions
 To raise awareness, inform and educate
 To provide a comprehensive data and information resource to scientists, doctors and
epidemiologists, both in UK and worldwide.
The Air Quality Archive is also the national repository for historical ambient air quality
measurements and emissions data. It contains measurements from automatic measurement
programmes dating back to 1972, together with non-automatic sampler measurements dating back
to the 1960s. The Archive brings together into one coherent database both data and information
from all the UK’s measurement networks.
Similar national archives have also been developed for Scotland, Wales and Northern Ireland:
 The Welsh Air Quality Archive at www.welshairquality.org.uk
 The Scottish Air quality Archive at www.scottishairquality.co.uk
 The Northern Ireland Archive at www.airqualityni.co.uk
Together, these four national websites provide a comprehensive resource for data and analyses
covering all aspects of air quality throughout the UK and all its regions.
The UK Air Quality Archive also provides a twice-daily air quality forecast, which is further
disseminated via email and the Air Pollution Information Service, a free telephone service on
0800 556677.  Latest forecasts are issued twice daily, at
http://www.airquality.co.uk/archive/uk_forecasting/apfuk_home.php
 The National Atmospheric Emissions Inventory on www.naei.org.uk
 The Scottish Government Air Quality pages on
http://www.scotland.gov.uk/Topics/Environment/Pollution/16215/4561
 The Welsh Assembly Government Environment link at
http://www.wales.gov.uk/subienvironment/index.htm
 The Northern Ireland DoE Environmental Policy Division website at
http://www.doeni.gov.uk/epd
Detailed pollutant emission data for the UK are available from the National Atmospheric Emissions
Inventory (NAEI) at www.naei.org.uk . Air Pollution in the UK 2009- Edition A
26
References
1. European Commission “Directive 2008/50/EC Of The European Parliament and of
the Council of 21 May 2008 on ambient air quality and cleaner air for Europe “
[online]. Available at http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:152:0001:0044:EN:PDF [Accessed
9
th
Sep 2010].
2. European Commission “Directive 2004/107/EC of the European Parliament and of
the Council of 15 December 2004 Relating to Arsenic, Cadmium, Mercury, Nickel
And Polycyclic Aromatic Hydrocarbons In Ambient Air “ [online]. Available at
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9
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Sep 2010].
3. CEN “EN 14625:2005 Ambient air quality – standard method for the measurement
of the concentration of ozone by ultraviolet photometry”
4. CEN “EN 14211:2005 Ambient air quality - Standard method for the measurement
of the concentration of nitrogen dioxide and nitrogen monoxide by
Chemiluminescence”
5. CEN “EN 14212:2005 Ambient air quality – Standard method for the measurement
of the concentration of sulphur dioxide by UV fluorescence” [
6. CEN “EN 14626:2005 Ambient air quality - Standard method for the measurement
of the concentration of carbon monoxide by non dispersive infra red
spectroscopy”
7. CEN “EN 12341:1999 Air quality. Determination of the PM10 fraction of suspended
particulate matter. Reference method and field test procedure to demonstrate
reference equivalence of measurement methods.”
8. CEN “EN 14907:2005 Ambient air quality - Standard gravimetric measurement
method for the determination of the PM2.5 mass fraction of suspended particulate
matter”
9. CEN “EN 14902:2005 Reference method for determination of Pb/Cd/As/Ni in
ambient air”.
10. CEN “EN 14662-1:2005 Ambient air quality - Standard method for measurement of
benzene concentrations - Part 1 : Pumped sampling followed by thermal
desorption and gas chromatography”
11. CEN “EN 14662-3:2005 “Ambient Air Quality - Standard method for the
measurement of benzene concentrations - Part 3: Automated pumped sampling
with in situ gas chromatography”
12. CEN “EN 15549:2008 Air quality - Standard method for the measurement of the
concentration of benzo[a]pyrene in ambient air”
13. Grice, S. E. et al. (2010) “UK air quality modelling for annual reporting 2008 on
ambient air quality assessment under Council Directives 96/62/EC, 1999/30/EC
and 2000/69/EC” (AEA report: AEAT/ENV/R/2859 Issue 1) [online]. Available at
http://www.airquality.co.uk/reports/cat09/1007201636_dd122008mapsrep_v4.pdf
[accessed 7th Sep 2010].Yap, F. et al. (2009) “UK air quality modelling for annual
reporting 2008 on ambient air quality assessment under Council Directives
96/62/EC, 1999/30/EC and 2004/107/EC” (AEA report: AEAT/ENV/R/2860 Issue 1).Air Pollution in the UK 2009 – Edition A
27
14. Kent, A. J. et al. (2010) “UK and Gibraltar air quality modelling for annual reporting
2008 on ambient air quality assessment under Council Directives 96/62/EC and
2002/3/EC relating to ozone in ambient air” (AEA report: AEAT/ENV/R/2860 Issue 1).
15. Defra (2010) Air Quality Archive (homepage) [online] Available at
http://www.airquality.co.uk/index.php [Accessed 7
th
Sep 2010].