Air pollution, for example from road transport, harms our health
and wellbeing. It is estimated to have an effect equivalent to
29,000 deaths each year and is expected to reduce the life
expectancy of everyone in the UK by 6 months on average, at a cost
of around £16 billion per year. Air pollution also damages
biodiversity, reduces crop yields and contributes to climate
Why is air quality important?
Air pollution is one of the 20 leading risk
factors for disease and contributed more than 2% of the annual
disability-adjusted life years (DALYs) lost in the UK in the 2010
Global Burden of Disease comparative risk assessment1.
This study estimated that in the UK over 360,000 disability
adjusted-life-years lost were attributable to ambient (outdoor) air
pollution in 2010 although this was a marked improvement from 1990
where the estimate was 996,000. However, air pollution still has a
much greater impact on health than risk factors such as second-hand
smoke, where only 43,000 attributable DALYs were estimated for 2010
1. This impact is mainly due to air pollutants,
especially small particulates (PM2.5),
increasing the risk of heart and lung conditions.
Link to Figure 1: Burden of Disease attributable to 20
leading risk factors for both sexes in 2010, expressed as a
percentage of UK disability adjusted life
What is air pollution?
Air pollutants are generated by a mixture of
natural and man-made (anthropogenic) processes and are released
into the air, often reacting with other chemicals (chemical
transformation). The distribution of these pollutants will depend
on the size of the molecule and weather patterns, with some
pollutants being mainly deposited locally and some affecting sites
in other world regions e.g. ozone. For example, in spring 2014
there were two peaks of air pollution in the East and South East of
England caused by a combination of high levels of air pollution
already existing in urban areas and exacerbated by Saharan dusts
and easterly winds bringing pollutants from mainland Europe. These
periods of poor air quality resulted in a significant increase in
respiratory conditions presenting to health care services including
NHS, GP in hours, GP out of hours and emergency
departments2. It was estimated that the national excess
consultations for wheeze or breathlessness issues was an excess of
1,200 GP in hours consultations during the first episode and 2,300
excess consultations in the second air pollution
There are many pollutants that impact health and the UK Air
Quality Standards Regulations 20003 which sets standards
- Particulate Matter (PM10 and
- Nitrogen Dioxide (NO2)
- Ozone (O3)
- Sulfur Dioxide (SO2)
- Benzene and Benzo(a)pyrene
- Carbon Monoxide (CO)
The majority of air pollutants have declined
over time in the UK, but particulates, nitrogen dioxide and ozone,
are still at levels that can harm health. Ozone is not deemed to be
a local pollutant, as formation takes place over some time, and may
be a result of emissions from thousands of kilometres away. Ozone
is not monitored in the Bedford Borough area, given its more global
prevalence. Bedford Borough Council currently monitors for
NO2 but not particulates such as PM10 and PM
2.5. Nevertheless, the effect on health has been
The Facts – Particulate Matter (PM10 and
What are PM10 and
Particulate matter is a mixture of solid
particles and liquid droplets in the air. PM10 are
particles of material that are 10 micrometres across or smaller,
PM2.5 are particles of material that are 2.5 micrometres
across or smaller5.
Why PM10 and
These have been chosen as these sizes are
likely to be inhaled into the lungs. The smaller the particles the
greater the potential impact because of their ability to penetrate
deeper into the lung. Particulate matter affects both respiratory
and cardiovascular diseases5.
Although small particulates (PM2.5)
have local sources, similarly to Ozone, it also has non-local
sources, with some of the more significant components of the total
concentration being outside the control of the UK3. This
is a key problem for local mitigation initiatives.
Figure 2: Average number of days when
levels of Ozone, Particulate Matter, Nitrogen Dioxide and Sulphur
Dioxide were moderate or higher at urban sites in the UK, 2010 -
Sources of Particulate Matter
Particles in the air arise from a variety of
natural and man-made sources and are classed as either primary or
Erosion of soil and rocks.
Combustion processes – both domestic combustion (wood/coal burners)
and industrial (power generation).
Transportation – primarily diesel emissions.
Transportation – Non-exhaust emissions (attrition of road surfaces
and wear and tear of tyres and brakes).
Industrial sources – construction, waste, aggregates
Released directly into the air.
Formed in the atmosphere by the chemical reaction of gases, first
combining to form less volatile compounds which in turn condense
For PM2.5 not all sources are local
as in some weather conditions, air polluted with PM2.5
from the continent may circulate over the UK (long range
transportation) especially the East and South East of
Figure 3: The sources of particulates in
Source: National Atmospheric Emissions
Emissions of particulate matter in the UK has
been reducing for the last 40+ years. It was estimated that there
was 462 Ktonnes of particulates emitted into the UK atmosphere in
1970 compared with 122 Ktonnes in 20136.
The Facts – Nitrogen
Nitrogen dioxide (NO2) is primarily
a secondary pollutant produced by the oxidation of nitric oxide
(NO) by ground level ozone. Nitric oxide is produced by the
reaction of nitrogen and oxygen in the combustion
process7. The largest source of nitrogen oxides in the
UK is the combustion of fossil fuels, particularly by motor
transport and non-nuclear power stations8.
Figure 4: The sources of Nitrogen Dioxide in 2014
Source: National Atmospheric Emissions
Nitrogen dioxide is an irritant gas which has
serious and, sometimes, fatal effects on health when inhaled in the
very high concentrations associated with accidental exposures. Its
properties as an oxidising agent can damage cell membranes and
proteins. At relatively high concentrations it causes acute
inflammation of the airways.
Air Quality Standards recommend a standard of
40µg/m3 as an annual average with an hourly mean of
200µg/m3 not to be exceeded more than 18 times a year
(target set to be met by 31 December 2005). Nitrogen dioxide is
measured continuously at the active monitoring sites in Bedford
town Centre and monthly at the 46 passive diffusion sites. There is
strong evidence to show that NOx nationally is
What impact does air pollution have on
The World Health Organisation (WHO) has
coordinated several key initiatives to summarise the data on air
pollution and health:
REVIHAAP (2013)9: a review of the
evidence on health
aspects of air
pollution, which summarises the current literature
available on the short and long-term impact of various
HRAPIE (2013)10: health
risks of air
Europe which provides recommendations for values
that should be used to assess the risk associated with increasing
levels of particulate matter, ozone and nitrogen dioxide. These
concentration–response functions can be used to assess the
cost–benefit analysis of particular interventions.
WHO Expert Meeting (2014)11: on methods and tools for
assessing health risk of air pollution.
Additionally, the UK Committee for Medical Effects of Air
Pollution (COMEAP) have identified that further study needs to be
undertaken in to the health effects of NO2. This is to
strengthen the evidence base in order to provide clearer advice to
UK health departments on the effects of indoor and outdoor air
pollutants on health12.
Health Impact of
There is a different deposition pattern of
fine (PM2.5) and coarse (PM10) particles of
pollution with coarse particles having a higher deposition
probability in the upper airways and bronchial tree. Larger
particles in the upper airways are normally cleared rapidly through
mucus and other mechanisms, as long as these methods are not
affected by underlying diseases such as asthma. Therefore
PM10 tends to have a more direct, short-term impact on
people’s respiratory symptoms and health13.
Evidence suggests that PM10
- Post neonatal (1- 12 months) all-cause
infant mortality (long-term exposure).
- Prevalence of bronchitis in children
6-12 years (long-term exposure).
- Incidence of chronic bronchitis in
adults (long-term exposure).
- Incidence of asthma symptoms in
children with asthma (short-term exposure)
Particulate air pollution (PM10 and
PM2.5) is a complex mixture of many chemical components
and it is unclear which components are particularly harmful to
health17. In March 2015, COMEAP17 released a
statement that advises “the evidence is mixed and remains
insufficient to draw reliable conclusions about which are the most
health-damaging components or sources of ambient particulate
Health Impact of
Unlike particulates, NO2 is a gas
and therefore disperses differently from traffic sources and can be
inhaled deep into the lungs. Although epidemiological evidence
associates exposure to NO2 with adverse effects on
health, there is some discussion as to whether NO2 is
just an indicator for other toxic elements of vehicle
Nevertheless, NO2 has been linked
with increased hospital admissions regarding respiratory issues,
adverse birth outcomes and increased mortality9. There
is also some evidence to suggest that NO2 has an
increases number of deaths from cardiovascular disease12
particularly when you consider short term exposure.
Long term exposure to NO2 is
reported to have associations with respiratory and cardiovascular
morbidity, children’s respiratory symptoms and lung
function12. However, there is currently insufficient
evidence to solely link NO2 to these conditions.
Nevertheless, it is absolute that air pollution is causing people
to become ill or exasperate existing conditions and 2008 saw 75 000
hospital admissions and 1300 deaths due to the exacerbation of
asthma in the UK18.
In March 2015, COMEAP12 released a
statement on the effects of NO2 on health – “Evidence associating
NO2 with health effects has strengthened substantially in recent
years and we now think that, on the balance of probability, NO2
itself is responsible for some of the health impact found to be
associated with it in epidemiological studies”.
Who is most impacted by air pollution
Children, the elderly and those with
pre-existing respiratory and cardiovascular disease are known to be
more susceptible to health impacts of air
There is significant inequality in exposure to
air pollution and related health risks: air pollution combines with
other aspects of the social, economic and physical environments
(Figure 5) to create a disproportionate disease burden in less
affluent parts of society19.
Figure 5: Socio-economic model of
Source: Defra, 200619
In England, the most deprived wards tend to experience the
highest concentrations of pollutants, although (except for
SO2) the least deprived wards also experience above
average concentrations of pollutants. This distribution can mainly
be explained by the higher proportion of deprived communities (and
very wealthy communities) in urban areas and the levels of
pollution due to road transport sources19.
The issue is greater though when looked at on
a more local level, where proximity to busy roads often results in
cheaper housing, leading to a disproportionate effect of air
pollution, noise pollution and pedestrian accidents on poorer
communities; also reinforcing social exclusion. Proximity to roads
has also shown adverse effects on health even after adjusting for
socio-economic status and noise. The precise pollutants responsible
are unclear, though may be some combination of ultrafine particles,
carbon monoxide, NO2, black carbon and metals that are
more elevated near roads9.
Vulnerable groups to air pollution include
young children and the elderly9. In 2006, Defra report
on air quality and social deprivation in the UK and estimated that
the young (0-14 years) were disproportionately affected by
PM10 and NO2 (Figure 7), experiencing the
highest cumulative concentrations as a higher proportion of this
age group reside in more deprived deciles where pollutant
concentrations are highest. The higher susceptibility of this age
group to air pollution implies an extra compounding effect,
increasing the inequalities already present. Similar has been
demonstrated when regarding NO219.
There have been some recommendations that
those with asthma should live at least 300m from major roadways,
especially those with heavy truck traffic, as levels of ultrafine
particulate matter decrease substantially by 300m, although this
distance varies among studies19.
Household (indoor) exposure to pollutants
For PM2.5, the particle is so small
that 40-70% of it can penetrate into indoor spaces where people are
working, and provides much of the exposure to particulate
Active urban adults in Europe spend an average
of 85-90% of their time indoors, 7-9% in traffic and only 2-5%
outdoors, with very vulnerable groups, such as infants and the
elderly, spending nearly all their time indoors. Therefore, due to
time, exposures indoors dominate overall air pollution
Therefore, policies that affect ambient
(outdoor) PM2.5 by 10µg/m3 will only reduce
the urban population exposure by 5-8µg/m3, as much of
their exposure time is indoors9. The average
infiltration of PM2.5 into buildings depends on
location, but also decreases as new, sealed air-conditioned
buildings replace older building stock. European standard EN 13779
specifies the required filter performance for good indoor air
quality in non-residential buildings taking into consideration
outdoor air quality.
WHO released a report stating that in 2012, 14,000 deaths in
high-income countries in Europe were attributable to indoor air
pollution25. A European Commission report advises that 2
million years of healthy life is lost annually due to indoor air
pollution, otherwise described as disability-adjusted life years.
The disability-adjusted life year (DALY) is a measure of overall
disease burden, expressed as the number of years lost due to
ill-health, disability or early death. Originally developed by the
World Health Organisation it is becoming increasingly common in the
field of public health and health impact assessment.
The majority of this health impact was due to
ambient (outdoor) air quality, mostly fine particulate matter, in
indoor settings (Figure 6), though it is worth noting that other
household dusts and mould contribute to indoor air pollution.
Figure 6: The indoor air pollution associated burden of
disease attributed to the key source of exposure in Europe
Source: European Commission, 201120
National and Local Air Quality Management
The European Union (EU) air pollution
legislation follows two complementary approaches:
- Controlling emissions at source.
- Setting of ambient air quality standards and
The member states then must transpose the
provisions of the EU Directives into their own national laws.
The Air Quality Directive and
Fourth Daughter Directive (2008/50/EC)21 covers the
following pollutants; sulphur dioxide, nitrogen oxides, particulate
matter (as PM10and PM2.5),
lead, benzene, carbon monoxide and ozone. This Directive sets
‘limit values’, ‘target values’ and ‘long-term objectives’ for
ambient concentrations of pollutants.
Limit values are legally binding and are set
for individual pollutants and comprise a concentration value, an
averaging period for the concentration value, a number of
exceedances allowed (per year) and a date by which it must be
achieved. Some pollutants have more than one limit value.
Target values and long-term objectives are set
for some pollutants and are configured in the same way as limit
values. Member States must take all necessary measures, not
entailing disproportionate costs, to meet the target values and
The UK Air Quality
Strategy22 has established objectives for eight
key air pollutants, based on the best available medical and
scientific understanding of their effects on health, as well as
taking into account relevant developments in Europe and the World
Health Organisation. These Air Quality Objectives are at least as
stringent as the limit values of the relevant EU Directives – in
some cases, more so. The most recent review of the Strategy was
carried out in 2007.
National Air Quality Statistics and
Indicators are reported for annual concentrations of
particles and ozone and the number of days in the year when air
pollution is ‘moderate or higher’. In addition, the Department of
Health23 has identified Public Health Outcomes Framework
which recognises the burden of ill-health resulting from
particulate pollution as well as a whole host of other public
health concerns. Specifically, the indicator is: “The fraction of
annual all-cause adult mortality attributable to long-term exposure
to current levels of anthropogenic particulate air pollution (human
This indicator is intended to enable
appropriate prioritisation for action on air quality in local
areas. The baseline data for the indicator have been calculated for
each local authority in England based on modelled concentrations of
fine particulate air pollution (PM2.5) in
2010. Estimates of the percentage of mortality attributable to
long-term exposure to particulate air pollution in local authority
areas range from around 4% in rural areas to over 8% in cities,
where pollution levels are highest.
Local Authority Air Quality Management
Areas are declared when the local authority review and
assessment process identifies an exceedance of an Air Quality
Strategy objective. The local authority must declare an ‘Air
Quality Management Area’ (AQMA) and develop an Action Plan to
tackle problems in the affected areas. In Bedford Borough, there is
one AQMA, this covers the majority of the town centre (see Figure
7) and particularly the A6 which makes up the High Street in
Bedford Town Centre. In light of proposed development within the
Bedford Borough Area, it is of note that the majority of
development sites are in areas of good air quality (Figure 8).
Bedford Borough Council’s AQMA
(Source: Bedford Borough Council,
Map showing appointment of growth 2016-2032
(Source: Bedford Borough Council,
What do we know about air pollution
levels in Bedford Borough?
In 2009, the Updating and Screening
Assessment29 was undertaken for the pollutants: carbon
monoxide, benzene, 1,3 -butadiene, lead, sulphur dioxide and
particulates PM10. It was identified that there was no
significant risk of the objectives being exceeded in the Borough
with regards to exceeding the government set limits. It was
identified that NO2 was exceeding the stated limit at
certain sites throughout the borough.
There are two types of monitoring for
Active monitoring is carried
out by continuous automatic monitors that can measure levels of
NO2. There two of these monitors due to their complexity
and expense. Both monitors are sited near busy roads (Figure
Data can be collected hourly and is summarised
as an annual mean or a period where a pollution exceedance has
occurred. These provide information on potential hot spots or areas
with at risk residents within the Bedford Borough Air Quality
Unlike NO2 and other key local air
pollutants, PM2.5 is not included within the Local Air
Quality Management Areas and there is currently no obligation on
local authorities to monitor PM2.5. There are currently
no sites in Bedford Borough that monitor for PM2.5.
Map of automatic monitoring sites
(Source: Bedford Borough Council,
Non-automatic monitoring of
NO2 is also carried out using diffusion tubes. Data is collected
monthly. There are 46 diffusion tubes at key locations within the
Bedford Borough Area (Figure 10).
Map of non-automatic monitoring sites in an around AQMA
(Source: Bedford Borough Council, 201529)
Background levels of pollution in the UK
Defra provides maps of modelled background
pollutant concentrations (Figure 11). In the UK, high annual
NO2 concentrations are mainly focused around roads,
urban and industrial areas, whereas background levels of
particulates are higher in the South and East of England, as these
regions receive a larger contribution of particulate pollution from
Annual mean background PM2.5, PM10 and NO2 retrospectively, 2014
Source: Defra, 201528
Air Quality in Bedford
As expected air pollution is greater near busy
roads, particularly where traffic builds up. Key roads are Bedford
High Street, Shakespeare Road, Prebend Street and Ampthill Road.
Although average levels of pollution are not necessarily above the
threshold, health impacts are seen at levels below
threshold9. There are no models of PM2.5 or
PM10 dispersion in the Bedford Borough area.
In Bedford, the annual mean objective for
NO2 is exceeded at a number of locations across the
Borough. All but one of the exceedances are within the town centre
AQMA, the site that exceeds outside the AQMA does not present
relevant exposure (people living or working in the vicinity).
In 2015 monitoring showed an
improvement overall in air quality, with all sites
demonstrating a reduction in concentrations of NO2
compared with previous years. Data collected showed that only 20%
of the monitoring locations are exceeding the annual mean
objective, compared to 32% in 2014.
In 2015, Lurke Street active monitoring
station measured an increase in the annual mean objective and a
decrease in the hourly mean objective when compared with the
previous year. Contrastingly the Prebend Street monitor measured a
decrease in NO2 concentrations in comparison with 2014.
Lurke Street monitoring station demonstrated exceedances of the
annual mean objective, whereas Prebend Street has been below the
limit for NO2 since 2012 (Figure 12). Figure 16
demonstrates the exceedances observed at NOx tube locations from
Figure 12: Trends in Annual Mean
Concentration of Nitrogen Dioxide Concentrations measured at
Automatic Monitoring Sites (2009 – 2014)
(Source: Bedford Borough Council, 20169)
Figure 13: Annual mean NO2 concentration
recorded from NOx Tubes 2010-2014
(Source: Bedford Borough Council, 20169)
In summary, local evidence suggests that the level of
NO2 in Bedford Borough is slowly improving
overall, nevertheless, air quality and reducing
NO2 concentration levels will remain a key priority for
the Borough Council.
Impact on health outcomes (Mortality
In 2014, Public Health England reported on
local mortality associated with long term exposure to manmade
PM2.530. Only manmade PM2.5 was
considered because at a local level it is considered “physically”
manageable. The report estimated that in Bedford the number
of premature deaths of people over 25 years in 2010 was equivalent
to 73 people. From exposure to man-made activity PM2.5
was 73 with associate life-years loss of 802. The associate
life-years loss adds up the number of years should the person die
before the age of 75y, this is significant because it demonstrates
that children are particularly vulnerable when compared to
There are at least 12 modelling tools that
combine air quality information, epidemiological derived
concentration response functions and demographics to estimate air
pollution related health impact11. All estimate
mortality impact, but only some estimate the broader health impact
(morbidity) through additional cases of key diseases and disability
adjusted life years.
There is uncertainty around the model inputs
for morbidity, especially around the concentrations response
function and the extrapolation of data from different populations
and different systems. Therefore, the model needs to be appropriate
for the context and evaluated individually, with a trade-off
between technical refinement and accessibility to the user.
At present, Bedford Borough does not have
specific estimates for the impact of air pollution on disease
prevalence and health care utilisation. Therefore, the health
impact on hospital admissions for respiratory and cardiovascular
admissions needs to be based on the general estimates provided in
Health Inequalities – Susceptible Populations in Bedford
There are a range of domains that can impact
on the health inequalities and level of deprivation that an
individual is exposed to. Environmental inequalities arise where
specific communities, such as the most deprived, experience a
poorer environmental quality, such as poor air quality. With air
quality children (aged up to 14 years) & elderly people (over
65 years) are deemed more susceptible to the impacts of air
pollution on their health and wellbeing.
Social inequalities may be exacerbated by air
quality factors. For example, the most deprived areas are often
located in close proximity to major transport axes, such as railway
stations or depots, main roads, busy junctions, airports and flight
paths. These areas are seen as less desirable to live but are often
the only areas that those on lower incomes can afford. As these
areas are often at the highest risk from air pollution residents
living in the area are also at greatest risk of the negative health
impacts from these pollutants.
Most of the AQMA in Bedford, and therefore the
area which contains the highest levels of air pollutants, is
contained within the Castle Ward area of the town. This is a mixed
ward with some of the most deprived areas of the borough within the
western area of the ward and the whole of the eastern area having
some of the more affluent areas (figure 17). The deprived western
end of the ward (471 followed by 466) is included within the AQMA
due to its poor air quality. The western area occupants experience
amongst the highest levels of unemployment in the Borough, high
numbers of limiting lifelong illnesses, high levels of crime and
overcrowding and are among the 10% most deprived areas in
England32. The social mix of this area of the ward
includes a relatively high proportion of ethnic minorities.
Addressing Local Need: What we can do about air
pollution in Bedford Borough?
Evidence around mitigation measure and
What is the
Consistent evidence has been reported that
links living near major roads and/or traffic-related air pollution
to adverse effects on health9. This suggests that a
positive health impact would be observed when moving away from
areas with high to areas with lower air pollution and
WHO (20139) summarised the evidence
regarding several types of traffic-related interventions and
Low Emission Vehicles as an option?
In Bedford, NO2 emissions from traffic is one of the
largest factors that results in poor air quality. The main source
of pollution from cars is from privately owned cars moving round
the Borough, particularly within the town centre. Traffic flows are
also hindered due to the river and subsequent bridges which results
often restrict the movement of cars through the town centre.
The Office for Low Emission Vehicles
(201443) is a good source of information to benchmark
how the government envisage a shift to low emission vehicles:
Taxis- where appropriate reducing license fees for taxi companies
who use low/ no point source emission vehicles43
Buses- retrofitting existing fleet vehicles to bring them up to a
higher Euro standard43 and working with operators to
phase out older, more polluting vehicles.
Rapid Charger Networks – Ensuring the electric car charging network
allows improve accessibility of charging borough wide and
particularly within new developments43.
Privately Owned Vehicles – Advertise consumer incentives for
purchase of electric vehicles which is a national initiative.
Incorporate local incentives such as allowing bus lane use for low
It was expected that the new versions of
diesel cars Euro 4 and Euro 5 would see significant reductions in
particulate matter emissions from traffic. Unfortunately the
reductions have not been as significant as originally predicted by
Government. Therefore air quality has not improved to the level as
New low emission vehicles are either fully electric with no
emissions at the point of use, or hybrid vehicles which have
significantly reduced emissions for periods of the drive cycle and
may be capable of some zero emission running. Therefore, with new
low emission vehicle technology there is the potential for
substantial real world cuts in emissions43.
Low emission zones as an option?
Defra have recently concluded a consultation
on their draft air quality plans that looked to improve air
quality33. This looked heavily into low emission zones
or clean air zones in the large urban areas such as Birmingham,
Yorkshire and Leicester. There is also limited evidence that low
emission zones are effective9.
Congestion charging zones as an
A study into the health benefits associated
with implementing the congestion charging zone in London showed
very modest impact on air pollution and public health9.
Cost and change in infrastructure would not necessarily be cost
effective particularly as there may be other methods more
appropriate in Bedford.
Lower traffic exposure as an
- Reduction in
traffic speeds has been seen to improve surrounding air
quality9. This is not currently relevant in Bedford
Borough area as the main issue with air pollution within the town
centre is more on preventing congestion than controlling the speed.
In the future this technique may be relevant to the new bypass that
has been built in the Borough due to the continued housing
development that is undertaken along the bypass corridor.
- The construction of
bypasses to relieve nearby congested streets have been shown to
improve particulate matter levels by about 28% as seen by in
Wales9. Fundamentally, the bypasses saw a reduction in
heavy good vehicles moving through areas of poor air quality
leading to this improvement. Similar may be seen in Bedford Borough
when the Western Bypass in completed in March 2016.
Breaking the pathway
Use of Vegetation (Natural Environment
and Green Space)
DEFRA (201034) released information
surrounding the impact trees can have on air pollution. Trees can
have a positive impact on air quality, but if appropriate strategic
considerations are not made before planting trees then there could
be a negative impact on the local air quality. Vegetation can
remove some gaseous pollutants by uptake or absorption and
particles can physically adhere to the vegetation35.
Importantly vegetation also alters the dispersion of emissions by
changing air-flow patterns, wind speed and surface roughness,
enhancing turbulence and mixing of pollutants. These elements could
be considered more important than the general uptake of pollution
Trees can alter the local meteorology such as
reduce air temperature which is believed to improve air quality
because emissions of many pollutants/ozone forming chemicals are
temperature dependent. However, if not correctly placed trees can
increase the air temperautre34. Similarly, appropriate
siting is required near buildings as reduced airflow on warm days
and shade on cold days can increase the amount of energy used to
regulate building temperature. Also, air pollution can be emitted
as a result of tree maintenance, which if not managed adequately
could offset any positive impacts of the trees35.
A study undertaken by the Forestry Commission
(201535) looked at a 10Km x 10Km mixed green space
consisting of trees, grass and other vegetation, the results
identified that the air quality improved to the extent that may
have saved two lives and reduce hospital emissions by just two.
Indoor Air Quality
Although the ambient levels of
PM2.5 are monitored in outdoor air, over 90% of our
exposure occurs indoors due to the large percentage of time spent
there20. Therefore, much of the health impact of
PM2.5 is due to indoor air quality demonstrating that
exposure to indoor air quality must be considered.
Indoor air exposure can be independently
controlled by reducing outdoor air pollution levels through
emissions reduction, effective urban planning and by controlling
indoor levels through filtration in building envelope and/or health
ventilation systems20. By doing this as well as
combatting indoor exposure to tobacco smoke could see the reduction
in burden of disease.
The National Planning Policy Framework
Guidance on Air Quality states that Local Plans can affect air
quality in a number of ways, including through what development is
proposed and where, and the encouragement given to sustainable
transport. Air Quality Management Areas should be taken into
account in plan making but also it is important to take into
account other locations where there could be specific requirements
or limitations on new development because of air quality.
Drawing on the review of air quality carried
out for the local air quality management regime, the Local Plan may
need to consider:
The potential cumulative impact of a number of smaller developments
on air quality as well as the effect of more substantial
The impact of point sources of air pollution (pollution that
originates from one place).
Ways in which new development would be appropriate in locations
where air quality is or likely to be a concern and not give rise to
unacceptable risks from pollution. This could be through, for
example, identifying measures for offsetting the impact on air
quality arising from new development including supporting measures
in an air quality action plan or low emissions strategy where
Bedford Borough Council does not have an air
quality policy for planning, each development is considered on a
case by case basis.
Reduction of person exposure – e.g.
Air pollution warning services can either be
active or passive. The UK Daily Air Quality Index
(DAQI)37 is a passive system similar to a UV or pollen
forecast, where levels of key pollutants (O3,
NO2, PM2.5, PM10 and
SO2) are scored (0-10) and summarised into four bands
(low moderate, high and very high)(38). These can then
be used, especially by those at risk, to adjust behaviour by
potentially reducing activity outdoors or using relieving asthma
inhalers more frequently (Figure 14).
Passive warning system for air quality levels (DAQI -
An active system uses the same information but
proactively alerts registered users of forecast pollution events
rather than leaving it to the responsibility of the user.
In the UK there are several systems:
airALERT: available for Surrey, Sussex, Southampton and Sevenoaks.
This system was developed and is provided by Sussex Air Quality
Partnership (Sussex-air) and ERG, King's College London
airTEXT: for London, developed and operated by CERC with other
partners in the airTEXT consortium (http://www.airtext.info/)
London Air iPhone App: developed by Environmental Research Group,
Kings College. (http://www.londonair.org.uk/london/asp/iPhone/)
The intention is that by providing
preventative information, this empowers users to reduce exposure or
increase medication to lessen or prevent the onset of symptoms,
with the knock-on-effect of reducing GP visits and hospital
A review of air pollution early warning systems found that the
evidence of behaviour was mixed with some indication that personal
perception of poor air quality drives behaviour change more than
validated data, although susceptible groups may be more aware of
the official alerts39
What are our current assets and gaps?
The public health function and responsibility
returned to local authority in 2012, since then there has been
limited data in place to quantify the health implications of poor
air quality. However, initial data is starting to be seen
particularly when considering PM2.5. This data is
providing the link between mortality and air pollution.
It is important that the continued development
of robust data and evidence continues in order to develop effective
policies to protect the public health of individuals locally. Data
such as this supports the development of effective targets within
the AQMA to improve air quality levels, adding add weight to
decisions taken to ensure that the targets are met with regards to
air quality objectives. It would be useful to identify data that
demonstrates the cost to the healthcare locally as a result of poor
air quality. The costs could then potentially be offset against the
changes that are required to protect public health.
The current air quality action plan will need
to be refreshed so that it includes detailed quantifiable actions
against which progress can be measured as well as highlighting the
health benefits arising from those measures. As required by DEFRA
the plan will be refreshed taking into account ongoing development
within the Borough.
There are strongly competing pressures that
need to be balanced to achieve regeneration and growth, while
protecting people’s health against poor air quality. Redeveloping
areas, such as the High Street, and bringing businesses back into
empty buildings is important for economic growth which needs to be
achieved alongside mitigating the potentially detrimental
consequences, such as increased traffic volumes, that come with
increasing the prosperity of the town centre.
Levels of air quality have not improved as
predicted nationally and locally, and in some cases air quality
levels have worsened. The challenges of improving air quality for
the Borough are as important today as they ever were, work will
continue to ensure air quality remains a key priority for the
Public awareness of air quality is increasing
along with the understanding of the detrimental health effects
associated with poor air quality. However, there still appears to
be a lack of understanding of how an individual’s actions can have
a positive impact on local air quality. This is particularly
relevant due to the greatest source of air pollutants in the
Borough is local private car usage, therefore behavioural changes
on an individual level is required to achieve change.
A greater awareness of the dangers associated
with poor air quality will drive individuals and agencies to change
their behaviours to shape a better environment. Greater emphasis is
needed to ensure air quality concerns are given equal consideration
as part of the development and design process. This will encourage
the synthesis of good development and a healthier environment.
Next steps: How can we address air
pollution in Bedford Borough Area?
Lower emissions from
Consideration could be given to:
Improving/increasing electric (rapid) charging network throughout
the Borough and consider other incentives for driving low emission
cars/ electric cars.
Improving the knowledge of purchasing a low emission vehicle
(privately owned cars).
Licensing incentives for Taxis who operate with low emission
Bedford Borough Council committing to move to low emission/ fully
electric fleet vehicles where appropriate.
Modal shift from cars to active
Switching journeys from cars to walking,
cycling and public transport not only has a large beneficial impact
on the individual’s health, but a wider benefit to the population
health as there are corresponding decreases in overall air
pollution levels. Mechanisms for doing this are dealt with in more
detail in the Active Transport section of the JSNA.
Further investigation into the
potential for reducing person exposure
While a lower emissions transport fleet and
modal shift provide the overall long-term momentum to reduce air
pollution, there are measures that may reduce personal exposure in
the short-term. These include:
Text alerts to vulnerable patient groups.
Better use of health evidence when assessing the populations
exposed in new developments.
Further analysis of data relating to respiratory conditions such as
asthma and COPD to see the level of correlation between areas of
poor air quality within the Borough. This will allow more targeted
measures to be identified within the action plan.
Further understanding around the seasonal impact of air pollution
and potential measures that could reduce this.
Ensure this data is well circulated within the
Council and is promoted and made readily available to local
residents, businesses and schools.
Air Quality Management
Refresh the air quality action plan to include quantifiable and
measurable targets, where the actions can be measured through
health benefits, cost savings to the community and local
Develop a revised Air Quality Strategy for Bedford Borough Council
taking into account the new air quality evidence both nationally
and locally, taking into account pollutants other than
Links with other JSNA
The JSNA process has developed a better
understanding of the key areas that air quality fit into other
departments within Bedford Borough Council. There are clear links
with the following JSNA Chapters:
- Natural Environment and Green Space
- Climate Change and Adaptation
- Cardiovascular Disease
- Respiratory Diseases: Asthma and Chronic
Obstructive Pulmonary Disease
- Economic Wellbeing
- Workplace Health
- Active Travel
Internal promotion is key to allow the full
engagement of all necessary departments of the Council to ensure
decisions consider air quality issues. The links between improving
air quality and the other Councils JSNA chapters and associated
departments need to be strengthened and developed.
1. Department of Health, 2014. Living Well for Longer:
National Support for Local Action to Reduce Premature Avoidable
Mortality [online] Available At:
2. Smith GE et al., Using real-time syndromic
surveillance systems to help explore the acute impact of the air
pollution incident of March/April2014 in England,
Environmental Research 2015; 136: 500–504
3. Air Quality Expert Group (for Department for
Environment, food and Rural Affairs) 2012. Fine Particulate Matter
(PM2.5) in the United Kingdom [online] Available At:
4. Defra, 2015. Defra National Statics Release: Air
Quality Statistics in the UK, 1987 to 2014 [online] available At:
5. Air Quality Expert Group, 2005. Particulate Matter in
the United Kingdom - Summary [online] Available At:
6. National Atmospheric Emissions Inventory, 2015. About
PM10 [online] Available At: http://naei.defra.gov.uk/overview/pollutants?pollutant_id=24
7. Air Quality Expert Group, 2004. Nitrogen Dioxide in the
United Kingdom - Summary [online]
8. National Atmospheric Emissions Inventory, 2015. About
Nitrogen Oxides [online] Available At: http://naei.defra.gov.uk/overview/pollutants?pollutant_id=6
9. World Health Organisation, 2013. Review of Evidence on
Health Aspects of Air Pollution – REVIHAAP Project – Technical
Report [online] Available At:
10. World Health Organisation, 2013. Health Risks of Air
Pollution in Europe – HRAPIE Project [online] Available At:
11. World Health Organisation, 2014. WHO Expert Meeting:
Methods and Tools for Assessing the Health Risks of Air Pollution
at Local, National and International Level [online] Available At:
12. Committee on the Medical Effects if Air Pollutants,
2015. Statement on the Evidence for the effects of Nitrogen Dioxide
on Health [online] Available At:
13. Guarnieri, M and Balmes JR, Outdoor air pollution and
asthma, Lancet 2014; 383: 1581-92 [online] Available At:
14. Environmental Audit Committee, 2010.
15. Bedford Borough Council, 2014. Respiratory Health.
16. Department for Environment, Food and Rural Affairs,
2012. National Air Quality Objectives [online] Available At:
17. Committee on the Medical Effects of Air Pollutants,
2015. Statement on the Evidence of Differential Health Effects of
Particulate Matter According to Source or Components [online]
18. Smallbone, K. (2010) Evaluation of Air Alert: Herts
and Beds, Brighton, University of Brighton.
19. Department for Environment, food and Rural, 2006. Air
Quality and social Deprivation in the UK: An Environmental
Inequalities Analysis [online] Available At:
20. European Commission, 2011. Building understanding of
the dangers of poor indoor air quality and actions to take or ‘Plan
B’: seal the building and get a good filter [online] Available At:
21. EU Directive, 2008. 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 [pdf] Available At:
22.. Department of Environment, Food and Rural Affairs,
2007. The Air Quality Strategy for England, Scotland, Wales and
Northern Ireland [online] Available At:
23.. Department of Health, 2014. Improving Outcomes and
Supporting Transparency – Part 2, 3.1 Summary Technical
Specifications of public Health Indicators [online] Available at:
24. World Health Organisation, 2014. Frequently Asked
Questions - Ambient and Household Air Pollution and Health
[online] Available At:
25. World Health Organisation, 2012. Burden of Disease
from Air Pollution [online] Available At:
26. Bedford Borough Council, 2015. Local Plan 2032-
Planning for the future. Consultations Paper 2015 [online]
27.. Department of Environment, Food and Rural Affairs,
2015. 2010-2015 Government Policy on Environmental Quality [online]
28.. Department of Environment, Food and Rural Affairs,
2015. Air Pollution in the UK 2014 [online] Available At:
29. Bedford Borough Council 2015. Updating and Screening
30. Public Health England, 2014. Estimates of mortality in
Local Authority Areas associated with Air Pollution [online]
31. Public Health England, 2015. Fraction of Mortality
Attributable to Particulate Air Pollution [online] Available At:
32. Bedford Borough Council, 2015. Ward Profiles[Accessed
33. Department of Environment, Food and Rural Affairs,
2015. Draft Air Quality Plans [online] https://consult.defra.gov.uk/airquality/draft-aq-plans
34. Department of Environment, Food and Rural Affairs,
2010. What Impact Do Trees have on Air Pollutant Concentrations?
[online] Available At: http://laqm.defra.gov.uk/laqm-faqs/faq105.html
35. Forestry Commission, 2015. Improving Air Quality
[online] Available At: http://www.forestry.gov.uk/fr/urgc-7edhqh
36. Department of Communities and Local Government, 2014.
Air Quality: What is the role of Local Plans with regard to air
quality? [online] Available At:
37. Department for Environment, Food and Rural Affairs,
2013. Daily Air Quality Index [online] Available At: http://uk-air.defra.gov.uk/air-pollution/daqi
38. Department for Environment, Food and Rural Affairs,
2014. What do the forecasts mean? [online] Available At: http://uk-air.defra.gov.uk/forecasting/what-forecasts-mean
39. Kelly, F., Fuller, G., Walton, H. and Fussell, J.
2011. Monitoring Air Pollution: Use of early warning systems for
public health. Official Journal of the Asian Pacific Society of
Respirology [online] Available At:
40. Atkinson, R., Baker, T., Fuller, G. and Walton, H.
2014. Air pollution alert services evidence development strategy –
Prediction of possible effectiveness and assessment of intervention
study feasibility [online] Available At:
41. Bedford Borough Council, 2013. Full report on the
major causes of premature mortality [pdf] Available At:
42. Andersen, J., de Nazelle, A., Hertel, O.,
Garcia-Aymerich, J., Mendez, M., Nieuwenhuijsen, M Overvad, K.,
Raaschou-Nielsen, O. and Tjønneland, A., 2015. A Study of the
Combined Effects of Physical Activity and Air Pollution on
Mortality in Elderly Urban Residents: The Danish Diet, Cancer, and
Health Cohort. Environmental Health Perspectives [online]
43 Office for Low Emission Vehicles,
2014. Investing in ultra low emission vehicles int he UK, 2015 to
2020 [online] Available At:
Back to top
To download and print a PDF version of this chapter, please