kingdom d.m. elsom, h. crabbe quality management areas ...€¦ · able to select from a range of...

Practical issues involved in developing effective

local air quality management in the United

Kingdom

D.M. Elsom, H. Crabbe

Air Quality Management Research Group, Oxford Brookes

Abstract

In 1995 the government finally accepted that local authorities should play a keyrole in managing air quality, especially with regard to the growing problem oftraffic pollution. It proposes a National Air Quality Strategy which requires localauthorities to review local air quality periodically. Where air quality standardsare not met, local authorities will be expected to designate such areas as AirQuality Management Areas (AQMAs) and to introduce measures to improve airquality over a specified timescale, subject to public consultation and governmentapproval. Local authorities are promised new pollution control powers forAQMAs and the government will consider the resource implications of this newlegislation. Whilst there is widespread support for these proposals this paperexplores the many practical issues which need addressing and resolving beforelocal air quality management will become effective where populations are at riskfrom poor air quality.

1 Introduction

There is widespread concern in the UK that traffic growth will progressivelyerode, and eventually outweigh, the air quality benefits arising from advancesin vehicle technology and the growing numbers of cars fitted with catalyticconverters (Royal Commission on Environmental Pollution*). Since 1970, thenumber of vehicles in the UK has increased by over 80% and the distancetravelled each year by 100% (Department of the Environment). Trafficprojections indicate current traffic levels may double by 2025 (Department ofTransport*). In urban areas such as London, road transport is the principal sourceof air pollution, accounting for 99% of CO emissions, 97% VOCs, 96% blacksmoke, 76% of NO* and 22% SO, (House of Commons Transport Committee*).

Transactions on Ecology and the Environment vol 6, © 1995 WIT Press, www.witpress.com, ISSN 1743-3541

484 Air Pollution Engineering and Management

Traffic emissions have been the cause of some serious pollution episodes (e.g.high N(X levels in London between 12-15 December 1991 which resulted in 160deaths) as well as being major contributors to regional O, episodes (e.g. manyparts of England in July 1994 and May 1995).

For several years, local authorities have pressed central government torecognise that local air quality problems cannot be solved solely by nationallegislation (e.g. Environmental Protection Act 1990) and economic instruments(e.g. differential pricing of unleaded and leaded petrol). They argue that localauthorities should be given the responsibility for managing local air quality.Recent pronouncements by the government's Department of the Environment(DoE ) indicate the government now accepts this claim. The DoE^ concludesthat "national policies do not ... impact uniformly in all areas" and "it is likelythere will remain significant 'hotspots\ particularly in congested urban centres,where air quality standards are unlikely to be achieved cost effectively by theapplication of national air quality policies alone". Consequently, "localauthorities should have the primary task of managing local air quality, in liaisonwith other local authorities, the environment agencies and governmentdepartments" (Williams ). This partnership with local authorities is now beingformalised through the government's National Air Quality Strategy which hasbeen added to the Environment Bill currently progressing through parliament.The greater role being proposed for local authorities would seem to reflect thesituation in many other countries where local strategies are often considered tooffer greater flexibility for air pollution control in a rational, cost-effectivemanner (Archer*).

2 The proposed National Air Quality Strategy

In its National Air Quality Strategy (DoE ) the government proposes to:a. require all local authorities to review air quality periodically. Initially, reviewsof most major urban areas are expected to be completed within the next twoyears. The government intends local authorities to "rely wholly or primarily onnational data" for their periodic review as well as the "expanding nationaldatabase of information from ... emission inventories and modelling researchwork"(DoE ). It promises to publish good practice guidance on assessing airquality later in the year.b. enable a local authority or group of authorities to designate Air QualityManagement Areas (AQMAs) in those areas where air quality standards are notmet or projected as unlikely to be met. National guidance will be provided onidentifying and managing AQMAs. The enabling powers will be similar toexisting local authority powers to declare Smoke Control Areas (first permittedunder the Clean Air Act 1956).c. require local authorities to publish a detailed assessment of local air qualitywithin an AQMA. Local authorities can bid for central funding to support thepreparation of this assessment. In the meantime, expansion of nationalmonitoring networks and research programmes are intended to recognise theneeds of potential AQMAs.


Air Pollution Engineering and Management 485

d. expect local authorities to develop a local information strategy within anAQMA. Authorities should provide daily air quality information andcontingency plans for advising the public if an episode of high pollution isexpected.e. place powers and obligations on local authorities and other relevant bodies toprepare plans for remedying air quality problems (as defined by nationallyagreed criteria so as to ensure consistency) in AQMAs. Local authorities will beable to select from a range of nationally agreed air quality policies to apply inproblems areas. The plans will be subject to government and public consultationwhen first submitted and will be reviewed periodically.f. require local authorities to obtain government approval of specific local targetsand timescales for AQMAs. While the primary role lies with local authorities,the government expects the proposed environment agencies to provide anappropriate and effective contribution. The government would retain powers tomodify or even reject plans.g. expect local authorities to secure the effective coordination of all activitiesand sectors (transport, industry and domestic) to improve air quality in the mostcost-effective manner. National guidelines on how this is to be assessed are tofollow.h. give the Secretaries of State reserve powers of action in those areas wherelocal authorities may, for whatever reason, be reluctant to act i.e. localauthorities can be required to declare an AQMA.

3 Air quality data needed to prepare an Air Quality Review

The new system of local air quality management will focus particularly on areasat risk. All local authorities will have a duty to review air quality periodicallyand if this shows that air quality problems exist, or are projected to exist, thenactions to improve air quality will be required. In order to produce meaningfulreviews local authorities need adequate monitoring capabilities. At presentrelatively few local authorities have sufficient local pollution monitors toproduce a meaningful Air Quality Review which could justify designation of anAQMA (despite the government intending that such a review be based onnational data) let alone provide the subsequent detailed assessment requiredbefore plans to remedy air quality problems can be formulated. This situationmust cast doubt on meeting the government's objective of "all local authoritiescompleting a review within the next two years" (DoE ).

Some local authorities have made considerable progress in establishing amonitoring network of sites with real-time analysers for a range of pollutantssuch as Birmingham, Bristol, Cardiff, Greater London, Leeds, Leicester andSheffield. The government recognises the value of such sites and has integratedseveral (e.g. Birmingham, London Bexley, Swansea) into its centrally-fundedEnhanced Urban Network (EUN). EUN Phase I stations monitor CO, NO%, O^,PMjo and SO? (whilst Phase II stations monitor VOCs). The government plansto expand the EUN Phase I network, first begun in 1991, to 24 sites by the endof 1996 - a year earlier than previously planned. These stations are located in



pedestrian precincts or parks in urban centres at least 30 m away from busyroads and the measurements are intended to be representative of city centrebackground air quality (QUARG ). However, what of city centre kerbside airquality and the spatial variation of air quality across an urban area? Is thenetwork capable of defining areas within an urban area that are subject to poorair quality? Such questions suggest that more monitoring sites are needed at arange of roadside, city centre and suburban locations in each urban area toenable a realistic assessment to be made of the air quality to which people areexposed (Elsorrr ). To improve monitoring capabilities, the government hopesto integrate around 35 local authority real-time monitoring sites into its nationalnetwork by 1997 providing they are comparable with national monitoring inrespect of siting, approved instrumentation and site operation (DoE ). Thegovernment will provide the telemetry to link the sites with a central datacollection point and a quality control service but the cost of establishing andoperating these sites would remain with the local authorities (POST").

The number of local authority sites with real-time multi-pollutant analysershas increased greatly in recent years but are there sufficient sites for all localauthorities to review their air quality with confidence? There are still manyauthorities with no real-time analysers. Currently, monitoring capability does notreflect need, simply the ability to pay. Table 1 lists the number and type of real-time analysers in 38 towns and cities outside the Greater London area. However,46 other UK towns and cities with populations exceeding 80,000 are not listedbecause they did not operate real-time monitors when the survey was undertakenin November 1994. Consequently they are unable to assess adequately whetherthey experience serious air quality problems or not, especially short-termepisodes of poor air quality (Crabbe and Elsom ). Most of these towns andcities operate four or more sites measuring NO% using diffusion tubes but is itsatisfactory to rely on such limited data for an Air Quality Review?

Some deficiencies in the availability of air quality data may be offset byusing a combination of numerical dispersion models and local emissioninventories. For example, relatively simple computer-based models (e.g. theCAR model) are used routinely to calculate kerbside air quality from traffic flowin the Netherlands where municipalities larger than 40,000 inhabitants arecharged with maintaining acceptable air quality in urban areas where emissionsare dominated by road transport (Eerens, Sliggers and Hout ). However, wouldit be appropriate to base an Air Quality Review, let alone designation of anAQMA, on such models without having undertaken any real-time pollutionmonitoring? Even with local authorities being given a statutory duty to preparean Air Quality Review, many will continue to have problems in funding thereal-time analyser sites that are surely needed. The government intend to offerlocal authorities the right to bid for central funds for purchasing monitoringequipment but only after an AQMA has been designated.

4 Designating Air Quality Management Areas (AQMAs)

The government see parallels between designating AQMAs and smoke control


Table 1. UK local authority monitoring networks, November 1994.own/City

BirminghamJristolSheffieldBathCambridgeCardiffDoncasterHuddersfieldLeedsLeicester.otherhamSouthamptonStockton-orvTeesBelfastBrightonCoventryD^L_~DudleyEdinburghGlasgow^ "_KingstonJJpon HullJverpool'MakJstoneManchesterMiddlesbrough^Newcastle upon TyneNorwich _OxfordPlymouthPortsmouthSatfordSandwellSwanseaWalsallSunderlandBradfordLuton

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Census)961,041376,146501,20278,68991,933279,055288,854373,127680 722270,493251,637196,864173,912475,967143,582294,387218,802304,615418,914662,853254,117452,450136,209404,861140,849259,541120,895110,103243,373174,697220,463290,091181,906259,488289,040457,344171,671242 190

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areas. However, there are significant differences. A smoke control area usuallycovers a very small part of an urban area and most local authorities haveadopted a phased programme of implementation lasting many years (not alltowns and cities have completed their programmes). The long time scale ofimplementation reflects the cost to the local authority and central governmentof providing grants to householders for converting heating appliances to burncleaner fuels. Only properties within the designated area are affected and thereare no adverse effects or costs for areas adjacent to smoke control areas.AQMAs will be very different. The area with unacceptable air quality -assuming the spatial extent can be defined adequately - may be relatively smallfor some pollutants (e.g. NO?, PM^, benzene) but measures and policies tocontrol transport emissions in order to improve air quality within the pollutionhotspot may have far-reaching consequences for people living and working inneighbouring areas. Controls on transport will extend far beyond the area ofpoor air quality. For a small urban area with one local authority the city centremay be the area of poor air quality whereas the pollution control plans willencompass the whole urban area. In sprawling urban areas controlled by severallocal authorities there may be several pollution hotspots and the control planswill need to cover the entire conurbation and even beyond. For some pollutantssuch as O, the AQMA could apply to an entire region.

5 National air quality standards

The government propose to introduce new national standards and targets for ninepollutants. These will be based on the findings of the government-appointedindependent Expert Panel on Air Quality Standards (EPAQS) set up in 1991.EPAQS has proposed health-based standards for benzene (5 ppb running annualmean, with a long-term aim for this genotoxic carcinogen of 1 ppb), carbonmonoxide (10 ppb running 8-hour average), ozone (8-hour standard of 50 ppb)and 1,3-butadiene (1 ppb running annual mean). EPAQS proposals for standardsfor NO2, PAHs, particulates and Pb will follow in 1996. Any early introductionof national standards may result in subsequent modification in the light of theproposed EU Directive on Air Quality Assessment and Management. The newnational standards are likely to include guidelines (long-term goal), intermediatetargets, and 'alert' thresholds which, if reached, would prompt immediateremedial action. The government intend "that air quality targets should berealised everywhere in the UK by the year 2005" (DoE ). However, air qualitytargets are less stringent than health-based air quality standards, so when arehealth-based standards expected to be met?

6 Informing the public

Surveys of local authorities in 1993 and 1994 found that a surprising number ofauthorities monitoring air quality failed to communicate air quality informationto the public on a daily basis (NSCA , Crabbe and Elsom ). Only an evensmaller number attempted to forecast local air quality so as to warn the public



of likely pollution episodes and those that did employed relatively crudetechniques. The absence of an appropriate local forecasting model is asignificant omission currently. Public access to current air quality informationand forecasts has been limited mostly to the government's freephone telephoneand teletext service started in 1990. 1-hour concentrations for NO?, O^ and SOjpollutants are grouped into four bandings to which descriptive terms are applied,namely very good, good, poor or very poor air quality. Benzene and 1,3-butadiene concentrations are also provided but are not banded. Also in 1990,national weather forecasts began including regional air quality forecasts at timesof poor or very poor air quality. The air quality bandings have been subject toconsiderable criticism which is why several local authorities (e.g. Birmingham,Bristol, Coventry, Middlesbrough and Plymouth) use a numerical and descriptivevariation on the government bandings. To avoid confusion a national scheme isessential but clearly there is need for a revision of the current bandings and theintroduction of an easily-understood format for reporting air quality to thepublic, perhaps using a combined pollutant index of the type employed in theUnited States.

In 1995 most local authorities operating real-time analysers finallyrecognised the importance of providing the public with hourly-updated airquality levels. Local air quality information is disseminated not only via thelocal media but also using electronic information display boards placed in publicareas. When AQMAs are designated it will become a government requirementto ensure that the public are kept informed of air quality levels.

7 New local authority powers for tackling pollution episodes

Summer and wintertime pollution episodes are likely to occur for some yearsuntil overall pollutant levels are significantly reduced. The government intendto specify an alert threshold for a pollutant or combination of pollutants whichdefines the level at which there is a potential risk of immediate and serioushealth damage to sensitive groups in the community. If the level is reached orapproached in an AQMA, it would trigger a mandatory obligation on localauthorities to take remedial action (DoE ). Empowering local authorities tointroduce emergency pollution control measures and policies during a pollutionepisode or even in advance of a forecasted episode is new to the UK. Duringrecent episodes local authorities and central government have attempted toreduce road transport emissions only through requests for voluntary action.

The most stringent measure to reduce transport emissions would be torestrict the number or type of vehicles entering a pollution hotspot, such as atown or city centre. Car drivers would need to be directed to use park-and-rideor other public transport facilities. Effective implementation would requireconsiderable advance planning in terms of installing automatic vehicle diversionand prohibition notices, traffic light rephasing, extra edge-of-city parking placesand additional public transport vehicles. The role of the media would be vitalin informing the public about the traffic restrictions and explaining thealternatives available to commuters and shoppers. Advance planning will be



needed to assess the likely air quality benefits that are expected fromintroducing traffic controls and so justify the actions taken. This will require theapplication of numerical modelling based on a network of air quality monitorsand a detailed local emissions inventory. The public will need convincing thattraffic restrictions are likely to result in significant air quality benefits overallrather than simply the pollution being moved to suburban or peripheral locationsdue to the resulting increased traffic volume and congestion in those localities.Changes in the spatial pattern of pollution levels due to traffic restrictions canoccur well beyond the urban area in the case of O^. After the pollution episodethe public will expect confirmation that the restrictions were indeed justified.There are serious doubts whether any UK urban area currently has the capabilityto provide such detailed air quality assessments.

Public justification of pollution control actions may have to extend beyondlocal residents as for example if traffic restrictions were to be imposed onmotorways passing close to or even through an urban area. An experiment isbeing conducted currently on the M25 (London Orbital) to assess how varyingthe speed limits may affect traffic congestion and air quality. Experiments likethis may help to decide whether traffic restrictions can be justified. However,more comprehensive air quality assessments such as undertaken in the town ofHeilbronn/Neckarsulm, north of Stuttgart, Germany, are needed in the UK. Thistown was closed for four days in June 1994 to all vehicles except those fittedwith three-way catalytic converters and the lowest emission diesel engines as anexperiment to measure the air quality impact. The result was a 40% reductionin road traffic and 50% increase in public transport use producing a 40% fall inNC>2 concentrations and a halving of benzene concentrations (Archer®). There areoccasions, albeit relatively few, when some urban centres in the UK are closedtemporarily to traffic for special events and these could provide opportunities toassess air quality variation due to changes in traffic flows and patterns.

8 Local authority powers for long-term air quality improvement

New local authority powers being considered by the government for use inAQMAs include powers to introduce traffic bans, kerb side emissions testing tohelp target gross polluting vehicles, and road pricing/congestion charging. Thegovernment's intention is to offer a range of new powers together with guidanceand criteria as to when they should be applied in an AQMA. This approach canbe summed up as 'local choice from a national menu of management options'.

Extending kerbside emissions testing powers to local authorities would helptarget the relatively few excessively polluting vehicles (i.e. poorly orinadequately maintained cars, lorries, buses and taxis) which make adisproportionate emission contribution. These gross polluters can be identifiedusing remote sensing roadside checks and made to account for their impact byon-the spot fines and a requirement to correct malfunctions within a specifiednumber of days or, in extreme cases, be taken off the road. Other vehicle controlpolicies being considered include classifying stationary buses and deliverylorries left with their engines idling unnecessarily as a statutory nuisance. The



compulsory retrofitting of exhaust control equipment to particular classes ofvehicles such as older buses could become a requirement in an AQMA. In areaswhere poor benzene air quality is experienced, and until the majority of vehicleshave large carbon canisters fitted, it may be appropriate to require petrol stationsto fit vapour recovery equipment to pump delivery nozzles. Permitting onlyreformulated or oxygenated fuels in AQMAs may be another possible controlmeasure. As well as regulatory measures it is desirable that economicinstruments are available to local authorities too, such as road pricing/congestioncharging (with the tolls being used to improve public transport). Bristol,Edinburgh and York have considered this possibility whilst Cambridge hasdemonstrated the roadside and vehicle technology needed for congestioncharging in a small pilot study.

Local authorities are to be encouraged to use existing transport and land-useplanning powers to greater air quality effectiveness. Planning policies can beused to improve local air quality in the long-term by controlling the location ofnew homes, shopping centres, workplaces and leisure facilities such thatdependency on the use of cars is reduced and more people use public transport,cycle or walk (Elsom ). Parking charges can be regulated to reduce traffic incity centres if combined with improvements in the comfort, safety, reliabilityand frequency of public transport. However, local authority influence may belimited in this respect. For example, Cambridge copes with 90,000 vehiclesentering the city each day but with 40,000 privately-owned workplace parkingplaces available, there is little to discourage many people driving into the citycentre. Local authorities need to be able to control private and non-residentialparking so as to encourage greater use of public transport. Government targetsfor a reduction in car use in urban areas would help the situation greatly. Thiswould encourage greater participation in ride-sharing schemes by businessessuch as introduced recently by Nottingham. Of course, increased governmentinvestment in public transport would help too.

Local authorities need detailed national guidance on the likely air qualityeffectiveness of various transport measures to reduce pollution. Relatively fewUK before-and-after pollution monitoring studies have been undertaken whichwould enable an assessment to be made of the spatial and temporal air qualitychanges resulting from such measures as traffic calming, pedestrian-only areas,public transport priority measures, park-and-ride schemes, restricted routes andlight rapid transport systems.

9 Conclusion: making local air quality management work

A growing number of local authorities have been developing local air qualitymanagement systems in recent years but progress has been uneven. For example,whereas several authorities now possess a useful network of real-time pollutionmonitors there are many with none. Central government proposes a National AirQuality Strategy which gives local authorities the responsibility of managinglocal air quality. If local authorities are to assess the state of their air quality inorder to decide whether they experience poor air quality they will need



appropriate financial assistance (e.g. to purchase and operate real-time analysers,to appoint extra staff to compile emissions inventories and apply numericalmodels). For those authorities who then designate AQMAs, not only will theyneed the powers to introduce appropriate transport control measures but theywill need financial help to ensure they have an effective local air qualitymanagement system in place to assess the likely consequences of the pollutioncontrol actions they propose to take.

References

1. Royal Commission on Environmental Pollution. 18th Report: Transport andthe Environment, HMSO, London, 1994.

2. (DoE) Department of the Environment. Air Quality: Meeting the Challenge,DoE, London, 1995.

3. (DoT) Department of Transport. Roads for Prosperity. HMSO, London,1989.

4. House of Commons Transport Committee. Transport-related Air Pollutionin London, HMSO, London, 1994.

5. (DoE) Department of the Environment. The Future of Air QualityMonitoring Networks in the UK, DoE, London, 1993.

6. (DoE) Department of the Environment Improving Air Quality: DiscussionPaper on Air Quality Standards and Management, DoE, London, 1994.

7. Williams, M. Update on government policy and initiatives. Paper presentedat the National Society for Clean Air & Environmental Protection (NSCA)Local Air Quality Management Spring Workshop, Northampton, March1995. NSC A, Brighton, 1995.

8. Archer, G. Use of air quality standards and local air quality management inthe European Union and other countries. Clean Air, 1995, 25, 16-27.

9. (QUARG) Quality of Urban Air Review Group. Urban Air Quality in theUnited Kingdom: First Report. DoE, London, 1993.

10. Elsom, D.M. The development of urban air quality management systems inthe United Kingdom. In Pollution Control and Monitoring, eds Baldasano,J.M., Brebbia, C.A., Power, H. and Zanetti, P., Vol. 2, pp. 545-552,Computational Mechanics Publications, Southampton, 1994.

11. (POST) Parliamentary Office of Science and Technology. Breathing in ourCities - Urban Air Pollution and Respiratory Health. House of Commons,London, 1994.

12. Crabbe, H. and Elsom, D.M. Local air quality management in the UKsurvey. Clean Air, 1995, 25, in press.

13. Eerens, H.C., Sliggers, C.J. and van den Hout, K.D. The CAR model: theDutch method to determine city street air quality. Atmospheric Environment,1993, 27B, 389-399.

14. (NSCA) National Society for Clean Air and Environmental Protection.Local authority air pollution monitoring NSCA survey. Clean Air, 1993, 23,121-129.


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