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For the Canadian Lower Fraser Valley Region April 2014
REGIONAL GROUND-LEVEL OZONE STRATEGY
Fraser Valley Regional District I Metro Vancouver I BC Ministry of Environment I Environment Canada I Port Metro Vancouver
II REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
AuthorsThis Strategy has been produced jointly by:
• Fraser Valley Regional District (FVRD)
• Metro Vancouver
• BC Ministry of Environment (BC MOE)
• Environment Canada (EC)
• Port Metro Vancouver (PMV)
Members from each of these organizations sit on a Regional Ground-Level Ozone Strategy Steering Committee (RGLOSSC), which is chaired by the FVRD andsupportedbyMetroVancouverstaff.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 1
PurposeTo develop a plain-language document that provides a foundation for policies to control ozone precursors intheCanadianLowerFraserValley.
Theobjectivesofthisdocumentare:(1)topresentthestateofscientificunderstandingaboutground-levelozoneformationinthisregion,(2)toestablishbroadpolicydirectionsbasedonthecurrentscientificunderstanding,and(3)toidentifyareasforfurtherstudy.
ThisStrategywillbealivingdocumentthatisupdatedasneededbytheRGLOSSCtoreflectnewresearchandpolicyinitiatives.
Responsibility for implementing this Strategy rests in the hands of each managing authority - the Greater Vancouver Regional District within the boundaries of the Metro Vancouver region and the Province of BC withintheconfinesoftheFVRD.
2 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
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Geographic ScopeAlthoughthisdocumentdescribesthestateofscientificknowledgeintheentireLowerFraserValley(LFV)airshed (see Figure 1), the policy recommendations are limited to the Canadian portion of the LFV region (MetroVancouverandthesouthwesternportionoftheFraserValleyRegionalDistrict).ThisgeographicscopeisconsistentwiththeapproachtakenbyCanadianagenciestoinventoryandmodelemissionsandairqualityintheregion.
The science supporting this document are based on observations of actual emissions monitored throughoutourregionoverthelasttwentyyears(“trends”),and,toalesserextent,computermodelling.Bothofthesetechniquesinvolvesomedegreeofuncertainty,especiallywithmoredetailedanalysis. Tocombatuncertainty,welookedatawiderangeoftrends,frommanystationsandinvariousdurationcombinations.Aswell,modellingresultswerecomparedwithtrendsandfoundtobeconsistent. Thisprovidesgreaterconfidenceinthefindings.
Figure 1: Lower Fraser Valley airshed.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 3
THE
‘GO
OD’ –
PROTECTIVE OZONE LAYER
THE ‘BAD’ – HARMFUL GROUND-LEVEL OZONE
The ozone layer protects the surface of the Earth from too much harmful UV radiation.
Air contaminants released when fuels are burned combine with VOC to form ground-level ozone.
What is Ground-Level Ozone?The term “ozone” can be confusing.Wehavebeentold that the “ozone layer” is critical to life on Earth and in needofprotection.However,while ozone in the upper atmosphere plays an important role protecting life on the planet from harmful ultraviolet radiation, ozone produced near the surface of the earth has environmental, health and economicimpacts.Thelatteris referred to as ground-level ozone.
Ground-level ozone forms when nitrogen oxides (NOX) and volatile organic compounds (VOC), the “precursor” chemicals, react in the presenceofsunlight.Sincesunlightisveryimportant in production of ground-level ozone, the highest levels are often observed during the summer.Ozonelevelstypicallypeakduringthelateafternoons of hot, sunny summer days with stagnant weatherconditions.
For more information about ground-level ozone, please see:
”The Good, The Bad … And the Ozone”
metrovancouver.org/services/air/Documents/GLOFactsheet.pdf
Figure 2: Ground-level ozone versus the ozone layer. Source: Caring for the Air 2012
4 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
Ground-Level Ozone Formation in the Lower Fraser Valley
Summertime Peak OzoneAlthough this region generally experiences good air quality, elevated ground-level ozone concentrations sometimes occur in the eastern portion of the regiononhotsummerdays.Figure3showsthatairquality stations in the eastern portion of the region
(eastern Metro Vancouver and southwestern FVRD) recordhigherpeakozoneconcentrationsthaninwesternpartsoftheregion.Thisisdueinparttothe weather conditions in the eastern portion of the valley, where temperatures are warmer and air circulation is more restricted due to the surrounding mountains.
Summertime ozone episodes occur under hot summerdayswithlightwinds.Onfairweatherdays thermal (temperature-driven) inversions often occur,settingthestagefortheformationofsmog.During an inversion, a layer of warm air settles over andtrapsalayerofcoolerairneartheground.Withthe region’s mountains limiting pollutants from dispersing horizontally and a thermal inversion
Whatcom CountyWhatcom County
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Canada-wide Standard
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‘... elevated ground-level ozone concentrations sometimes occur in the eastern
portion of the region on hot summer days.’
Figure 3: Ground-level ozone levels based on the Canada-wide standard metric for 2012. The Canada-wide standard is a measure of highest sustained level of ozone occurring during the year.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 5
limiting pollutants from mixing vertically, the conditions become ideal for sun-driven chemical reactions that convert VOC and NOx emissions into ozone and other by-products typically found in smog.
WithhigherpopulationdensityinMetroVancouver,the main ozone precursor emissions tend to be released in the western part of the valley, primarily fromthemorningcommute.Thesemorningemissionstendtobecarriedinlandbylightwinds.Exactly where these emissions (and hence smog) end up is governed by a delicate balance between thestrengthoftheslopeflow,seabreeze,andvalleysflow(seeFigures4a-c).
Three potential paths are:
1) Up the slope of the North Shore mountains;
2) Towards Abbotsford;
3) TowardsChilliwackandbeyondtoHopeorupHarrisonLake.
Atnightthewindflowstypicallyreversedirectionleadingtothemergingofweakoutflowsfromthetributaryvalleys,drainageflowsfromthemountainsandthelandbreezeblowingdownthevalley.Thesenocturnal winds tend to push whatever ozone that was produced during the day and any left-over precursoremissionstowardthecoast.Thesemaybe either vented into Georgia Strait (sometimes ending up over the Gulf Islands) or re-circulated by thenextday’sseabreeze.
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VALLEY FLOW
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Figure 4 a-c: Summertime peak ozone season day and nighttime airflow patterns in the Canadian Lower Fraser Valley, showing slope flow, sea breeze and valley flow.
6 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
Springtime Moderate-to-High OzoneFortunately,summertimepeakozonelevelsarecoming down – there are fewer extremely high ozonedaysovertime.Thisisgoodnews,especiallyfor areas in eastern parts of the region which tend tohostthesepeakozoneoccurrences.However,non-peakozonelevelshavebeenrisingovertimein both the western and eastern portions of our region.Thistrendisofconcernbecauseofthehealtheffectsassociatedwithchronicexposuretoozone.Theaverageozonelevelisrisingovertime,whichrunstherisksassociatedwithchronicexposure.Thisisofconcernbecausetherearenoknownsafelevelsofozoneexposure.Seetheboxonpage14formoreinformationontheimpactsofground-levelozone.
Contributing to rising annual average ozone levels areincreasesinozonelevelsinthespring.Thereare several explanations for the elevated springtime ozone phenomenon:
1) Rapid photochemical reactions in the springtime duetohigherUVasdaylighthoursextend.
2) Ozone transport from Asia due to faster jet streaminthespringtime.
3) Troposphericmixinginthespringtime.
4) Stratosphericintrusions–transportofairrichinozonefromthestratosphere.
All of these phenomena result from natural meteorological forces and cannot be addressed by thisStrategy.
‘peak ozone levels are coming down’
‘non-peak ozone levels have been rising’
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 7
Monitoring Background Ozone in Ucluelet
In partnership with the BC Ministry of Environment and Environment Canada, Metro Vancouver continues toprovidesupportfortheWestCoast Marine Boundary Layer BackgroundStationlocatedinUclueletonVancouverIsland.Thebackgroundstation,locatedatthe
Amphitrite lighthouse, is a remote station positioned to monitorbackgroundairqualityintheloweratmosphereonthewestcoastofBC.
Thebackgroundstation,establishedin2010,willallowamorecompleteunderstandingtobedevelopedoftheeffectofbackgroundairmassestransportedintoBConlocalandregionalairquality.
Background Ozone LevelsAnotherkeyconcernintheregionistheriseofbackgroundozonelevels.Untilfairlyrecently,airpollution in the LFV was thought to originate entirely within the region.Withintensifyinguseoffossil fuels globally, particularly in Asia, medium and long range transport of pollutants from human activity is creating an impactonbackgroundozonelevelsintheLFV.Backgroundozone is the level of ozone that is present even without local contributingemissions.Whenground-level ozone is measured asanannualaverage,wefinda slight upward global trend of about 1 to 5 parts per billion per decade.Wehavelimitedabilitytocontrol this global trend, but we needtoprepareforit.
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Autumn Figure 5: Background Ozone Levels by season as measured at a number of remote sites along the Pacific coast and at Mace Head, Ireland. North American sites are based on 1-hr average ozone concentrations during the presence of high (>3m/s, except > 2m/s at Olympic NP) northwesterly wind (225 deg <wind direction <360deg). For Mace Head, monthly mean ozone data from the Derwent et al. (2007) study was used and 3-month seasonal averages were calculated based on those numbers. (Source: Parrish et al., 2012)
‘... rise of background ozone levels.’
8 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
Emission Sources Air pollution results from an interaction of meteorology,chemistryandemissions.TheLFVis an urbanized area with relatively few industrial sources.Mostoftheregion’s2.5millioninhabitants
areconcentratedinMetroVancouver.Movingeastward from Metro Vancouver, the region becomes increasingly rural, with agricultural activity dominating.Towardsthesouth,anindustrialareaextendsalongthewesternportionofWhatcomCounty,endinginthecityofBellingham.
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Figure 6: 2010 NOx emissions for the LFV by geographic location and source sector. Note that the width of the bars represents the relative amount of emissions from the two regional districts.
Figure 7: 2010 VOC emissions for the LFV by geographic location and source sector. Note that the width of the bars represents the relative amount of emissions from the two regional districts.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 9
In2010,NOx emissions were dominated by mobile sources,namely,carsandtrucks(onroad),nonroadequipmentandships(asillustratedinFigure6).Naturalgasuseinhomes,officesandindustryalsoplaysaroleinNOxemissions.In2010,thechemicalproductssector(e.g.industrial,commercial,andconsumerproductslikepaints,stains,varnishes,solvents, and thinners) became the main anthropogenicsourceofVOC,overtakingcarsandlighttrucks(asshowninFigure7).
NOx emissions are projected to decrease continuouslyoverthe20-yearforecastperiod,primarily due to strict engine emission standards (seeFigure8).VOCemissionsshowadecliningtrenduntil2020,afterwhichemissionsareprojectedtoincrease due to increase in chemical products use (seeFigure9).
The amount of ozone that forms is dependent on both the absolute and relative amounts of NOx and VOC; therefore the future emissions trends and locationoftheemissionsareimportanttoconsider.The relative amount of NOx-to-VOC appears to be decreasing.Thisconceptwillbeexploredindetailinthenextsection.
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Figure 9: VOC emissions trend for the LFV by location, including a low, moderate and high forecast for the LFV Total.
Figure 8: NOx emissions trend for the LFV by location, including a low, moderate and high forecast for the LFV Total.
10 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
VOC versus NOx LimitationGround-level ozone is created when NOx andVOCinteractinthepresenceofsunlight.The amount of ground-level ozone produced depends on the absolute and relative amounts of NOxtoVOC.Atanoptimalratio,wegetlotsofozone.
WhenthereisinsufficientNOxtoformozone,an area or neighbourhood can be called “NOx limited”.WhenVOCarelacking,anareacanbecalled“VOClimited”.Reducingthewrongpollutant can either produce no reduction in ozone concentration or worse, inadvertently increaseground-levelozone.Itiscritical,therefore to understand whether an area is NOxlimitedorVOClimited.Seepage11forananalogy that compares ground-level ozone to noisydrumming.
Atmospheric scientists studying the LFV now understand that the region can be both NOx and VOC limited and that the ratio varies both geographicallyandovertime.
In order to develop a Ground-Level Ozone Strategy, it is important to understand and anticipate the changes in the relationships betweentheprecursors.
The western part of the region is consistently VOClimited.Thismeansthatinordertoreduceozone production, VOC should be reduced in thisregion.ThisgeographicareaisroughlydefinedasthepartsofMetroVancouverwestand south of Port Coquitlam, Langley and Pitt Meadows.Withadensepopulationandhightrafficvolumes,thewesternpartoftheregionproducesasignificantamountofNOxemissions.Additionally, there are fewer natural sources of VOC(e.g.,vegetation)inthewesternportionofMetroVancouver.Figure10showstheannualNOx emissions and Figure 11 shows the annual VOCemissionsbymunicipality.Thisclearlyshows that NOx emissions are highest in the west and progressively decrease as you move eastward.Studiesconfirmthatthewesternportion of the region is VOC limited on all days, irrespectiveoftemperature.
Figure 10: Total NOx emissions in 2010 by municipality
Figure 11: Total VOC emissions in 2010 by municipality
Figure 12: Human-induced VOC emissions in 2010 by municipality
‘The western part of the region
is consistently VOC-limited.’
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 11
Figure 10: Total NOx emissions in 2010 by municipality
Ground-Level Ozone as Noisy Drumming?The formation of ground-level ozone could be compared to unpleasant,noisydrumming.Creationofthisear-offendingsituation (which is analogous to creation of ground-level ozone) requires a ratio of drummers to drum sets (or, VOC toNOx);inthiscase,theratioisone-to-one.Whenonedrummer is combined with one drum set, noisy drumming ensues.Themoredrummersanddrumsetcombinations,thegreatertheracket.Inasituationwherethereareexactlythe same number of drummers and drum sets (for example, 3 and 3 in the image below), removing either drum set or drummerwillreducethenoisegenerated.
In many cases, however, the number of drummers and drum setsismismatched.Whenthisoccurs,toquiettheroom,youneedtobemorestrategic.Forexamplewhentherearemore drum sets than drummers, to stop the noise, getting rid ofdrumsetsisineffective.Inthisscenario,ifyouremoveadrum set, the drummer will just move to an empty drum set andcontinuetomakenoise.Toreducenoise,youneedtogetridofdrummers.
Alternately, if there are more drummers than drum set, gettingridofdrummersisineffectiveinreducingthedecibellevel in the room, as for every drummer you remove; a standbydrummerisavailabletotake-overthenoise-making.Inthiscase,youneedtogetridofdrum-sets.
Keep in mind that this is a simplified illustration only which cannot capture
the full complexity of the chemistry.
12 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
The eastern part of the region is VOC limited on most days but NOx limited on the hottest summer days.Onthehottestsummerdays,moreVOCarereleasedfromnatural(e.g.trees)andhuman-madesources(e.g.,evaporationoffuelsandchemicals).These VOC combine with the available NOx emissions to form ozone, leaving an excess of VOC intheair.Thelimitingfactortoozoneformationon these days is therefore NOx ,notVOC.IfNOx can be reduced in the eastern portion of the region on the hottest days, ozone production should also be reduced.
A transition zone delineates the VOC and NOx limitedregions.Onhotsummerdaysthetransitionzone separates the region into a VOC limited region in the southwest and NOx limited region in the northeast.Theexactlocationofthetransitionzoneisinfluencedbyemissionsandmeteorologymovinggeographicallyovertimeandspace.This“zone”isdepictedinFigure13asashadedarea.Thisdepiction is estimated from air quality modelling andhistoricambientairqualitymeasurements.
‘ The eastern part of the region is VOC limited on most days but NOx limited
on the hottest summer days.’
‘A transition zone delineates the VOC and NOx limited regions.’
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Figure 13: VOC and NOx limited areas on the hottest summer days, based on CMAQ computer models using 2005 emissions. The shaded region, or Transition Zone, indicates the extent of the boundary between these two regions, due to meteorological variability.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 13
Goals
This Strategy has the following goals:
• Minimizechronicexposuretoground-levelozone.
• Minimizethefrequencyandseverityofacuteexposureto“peakground-levelozone”.
• Minimizeimpactonecosystems,plantlifeandagriculturalcropstoground-levelozone.
• Maximizeco-benefits(e.g.,reducedairtoxicsorimprovedvisibility).
14 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
Impacts of Ground-Level Ozone
HEALTH IMPACTS
Evidence from numerous studies over several decades indicates that exposure to ozone causes health effects.Thereiscurrentlymoreevidenceforacuteozoneexposureimpactsthanchronicexposureimpacts.
ACUTeexpOSUReHeALTHeFFeCTS CHRONICexpOSUReHeALTHeFFeCTS
• Respiratory impacts- reduced lung function, respiratory tract inflammation,respiratoryeffects(e.g.coughing, wheezing), exacerbation of pre-existingrespiratoryconditions(e.g.asthma)
- impaired immune response, increased susceptibility to respiratory infections
- increased emergency room visits, hospital admissions, use of respiratory medication
• Cardiovascular impacts-heartratevariability,elevatedbiomarker
counts indicating oxidative stress
• Central nervous system impacts-neurologicaleffects,includingshort-andlong-
term memory impairment and sleep impacts
• Mortality - increased number of cardiopulmonary-related
deaths
• Respiratory impacts- reduced lung function, asthma onset in
children, aggravated pre-existing respiratory conditions
- structural airway changes and lung tissue damage in animal toxicology studies
- increased emergency room visits, hospital admissions, use of respiratory medication
• Reproductive and developmental impacts - some evidence for increased pre-term births,
low birth weights
• Mortality - increased number of respiratory deaths
Scientistshavenotbeenabletodeterminea“safe”levelforozone.Thismeansthathealthbenefitscanalsobeachievedbyreducingexposureinareaswhereozonelevelsarealreadyrelativelylow.Thisisincontrastwithpollutantssuchassulphurdioxidewhichhavelowestobservableadverseeffectslevels,belowwhichnoimpactsarefound.environmentCanadaandHealthCanadahavedeterminedtheozonedose-responsecurvetobeapproximatelylinearaboveconcentrationsof10ppb.Beyondthatlevel,negativehealtheffectsincreaseinproportiontotheriseinconcentration.Toputthisincontext,backgroundozoneconcentrationsareabout25-35ppbacrossCanada,andareexhibitinganincreasingtrend.
ENVIRONMENTAL IMPACTS
plantsandcropscanalsobedamagedbyground-levelozone.
Plant exposure to ground-level ozone can result in visible injury, reduced growth and yield, and alternation ofcompetitivepatternswithinplantcommunitiesandecosystems(environmentCanadaandHealthCanada,1999;Guderianetal.,1985).Studiesconductedinthe1990sfoundthatground-levelozonewascontributingtoagriculturallossesofup4%,withavalueoftensofmillionsofdollarseachyearintheCanadianLowerFraserValley.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 15
Strategic Policy DirectionsThe following are guiding statements which are intended to advance policy and program development based on the strategy’s goals and the stateofthescience.ThesedirectionsemphasizethedifferentinfluencesofVOCandNOxduringpeakandnon-peakperiods.
Peak Ozone Periodspeakozoneperiodsrefertothehottestsummerdays,mostconducivetohighozoneconcentrations.Amorescientificdefinitionofpeakozoneperiodsarethetop2%ofdayswiththehighestozonereadings.
A1.Region-wide, continue current actions for ozone episodes.Trendshaveshownareductioninintensityandfrequencyofpeakozoneepisodesintheregionoverthepastdecade.This situation will continue to be monitored regularly.Inthemeantime,itisrecommendedthat existing programs and actions during high ozone days (such as ozone advisories) are continued.
A2.East of the transition zone, enhance NOx reductions. As this sub-region is NOx limited onpeakozonedays,measurestoreduceNOxemissions on these days will have the most benefit.Thesemeasurescouldbeshort-termandconnectedtoozoneadvisories.
A3.West of the transition zone, reduce VOC emissions during peak (and non-peak) periods. The western part of the region is VOC limited at all times; therefore reducing VOC emissions at all times will reduce ground-level ozoneproduction.Researchersconfirmthatreducing VOC in the western part of the region willnotadverselyaffecttheeasternpartoftheregion.
Non-Peak Ozone PeriodsAsidefromthe2%ofdaysconsideredpeakozonedays,therestoftheyearisconsideredanon-peakperiod.Sometimesnon-peakperiodsarereferredtoas“dayscontributingtotheannualaverage”.
B1.Region-wide, reduce VOCs to reduce ground-level ozone. Focus on VOC emitted during non-peakperiodsorthatcontributetoaverageemissions levels through policy measures that reduce VOC emitted constantly across all seasonsthroughouttheyear.
B2.Region-wide, reduce VOC emissions that are most reactive in the presence of sunlight and which lead to other co-benefits, such as reduced air toxics, improved visual air quality, greenhouse gases and reduced particulate matterformation.
B3.West of the transition zone, any NOx reductions need to be accompanied by equal or greater VOC reductions. As the western part of the region is clearly VOC limited, a reduction in NOx emissions, without a corresponding reduction in VOC emissions, could inadvertently increaseozonelevels.
16 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
Further ResearchThisStrategywillbealivingdocumentthatisupdatedasneededtoreflectnewscientificunderstanding.Belowaresomeareasinwhichresearchwillbefocused:
• Compiling data on the most reactive VOCs, including quantities, location and toxicity, in ordertoprioritizeemissionreductionefforts.
• Continualmonitoringtotrackhowcurrentpatternsshiftovertimeandre-evaluatingprogressregularly(everydecade).
• Modelling studies to understand the impact of NOx emissions in the western part of the LFVonground-levelformationbothwestandeastofthetransitionzone.
• ModellingstudiestounderstandtheimpactofNOxemissionsinthetransitionzone.
• The impact of changing meteorology: climate change is expected to generate further unpredictabilityintheexistingsystem.Oneofthelikelyeffectsismorefrequentandsevere“hotspells”,whichenhanceground-levelozoneformation.
• UnderstandingtrendsandlevelsofbackgroundozonetransportedtotheregionthroughmonitoringattheUclueletstationandaccessinginformationfromotherWestCoastbackgroundmonitoringsites.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 17
GlossaryAcute Exposure..................... Exposure to a pollutant for a relatively short amount of
time(e.g.,minutesorhours),typicallyatarelativelyhighconcentration.
Air Toxics................................ pollutantsthatareknownorsuspectedtocausecancerorotherserioushealtheffects,suchasreproductiveeffectsorbirthdefects,oradverseenvironmentaleffects.examplesinclude dioxin, asbestos, toluene, and metals such as cadmium,mercury,chromium,andleadcompounds.
Canada Wide Stds................. The Canada-wide standard is a measure of highest sustained levelofozoneoccurringduringtheyear.Itisbasedontheaverageofvaluesfromthethreemostrecentyears.Theconcentrations that are used in this averaging calculation are the fourth highest daily maximum 8-hour-average ozone concentrationforeachofthethreecalendaryears.
Chronic Exposure................. Exposure to a pollutant for a relatively long period of time (e.g.,monthsoryears),typicallyatamoderateconcentration.
Co-Benefits............................Secondary,or“side”,benefitsachievedfromreducingozoneorprecursorstoozone.examplesofco-benefitsincludereduced particulate matter, air toxics, greenhouse gases and visualairqualityimprovement.
Dose-Response......................Thechangeinhealtheffectscausedbydifferentlevels(concentrationsanddurations)ofexposure.
High Levels............................. Elevated ozone concentrations that are persistent in duration lastingfromseveralhourstoseveraldays.
Moderate Levels................... Slightly elevated ozone concentrations in the long term (basedontheannualaverage).
Ppb........................................... Parts per billion – expression of concentration, based on the proportionofasubstancein1,000,000,000partsofair.
Peak Levels............................Shortspikesinozoneconcentrationslastingaboutanhourorso.Theseoccurtypicallyinthesummertime.
Precursors.............................. A substance that participates in a chemical reaction that producesanothercompound.NOx and VOC are precursors to ground-levelozone.
Stratosphere......................... The layer of the earth’s atmosphere above the troposphere, extendingtoabout50kmabovetheearth’ssurface(thelowerboundaryofthemesosphere).
Stratospheric Intrusion....... Irreversible downward transport of stratospheric air into the troposphere.
Troposphere.......................... The lowest region of the atmosphere, extending from the earth’ssurfacetoaheightofabout6–10km,belowthestratosphere.
18 REGIONAL GROUND-LEVEL OZONE STRATEGY 2014
References• Ainslie,BandD.G.Steyn,2007:Spatiotemporal
Trends in Episodic Ozone Pollution in the Lower FraserValley,B.C.inRelationtoMeso-scaleAtmosphericCirculationpatternsandemissions.JournalofAppliedMeteorology.46(10),1631-1644
• Ainslie,B.D.,2004:Aphotochemicalmodelbasedonascalinganalysisofozonephotochemistry.ph.D.thesis,UniversityofBritishColumbia,Vancouver,B.C.,Canada,311pp.
• Ashmore,M.R.,2005,Assessingthefutureglobalimpacts of ozone on vegetation, Plant, Cell and Environment,
• Bovis,p.e.2003.StratospheretroposphereexchangeanditsinfluenceonsurfaceozoneconcentrationsinthelowerFraserValley.M.Sc.thesis,AtmosphericScienceprogramme,UniversityofBritishColumbia.
• environmentCanadaandU.S.epA,2004,“Characterization of the Georgia Basin/Puget SoundAirshed”.http://www.ec.gc.ca/Publications/BFA49636-3310-4AAA-BB55-8054B1791178/02AirshedGBPSreporte.pdf
• Fiscus,e.L.,Booker,F.L.andBurkey,K.O.,2005,Cropresponsestoozone:uptake,modesofaction, carbon assimilation and partitioning, Plant, Cellandenvironment,28,997-1011.
• Finlayson-pitts,B.J.andpitts,J.N.Jr,1993,Atmospheric chemistry of tropospheric ozone formation:scientificandregulatoryimplications,JournaloftheAirandWasteManagementAssociation,43(8),1091-1100.
• HealthCanada.CanadianSmogScienceAssessmentVolume2:Healtheffects.2013.
• Hedley,M.andD.L.Singleton,1997:evaluationof an air quality simulation of the Lower Fraser Valley-I.Meteorology.Atmosphericenvironment,31,1605--1615.
• Hedley,M.,R.McLaren,W.Jiang,andD.L.Singleton,1997:evaluationofanairqualitysimulationoftheLowerFraserValley-II.Photochemistry Atmospheric Environment, 31, 1617--1630.
• Hedley,M.,W.Jiang,R.McLaren,andD.L.Singleton, 1998: Modelling of future-year emissions control scenarios for the Lower Fraser Valley: Impacts of natural gas and propane vehicle technologies.JournalofAppliedMeteorology,37,1190--1204.
• HemisphericTransportofAirpollution2010.http://www.htap.org/
• Jaffe,Daniel,Heatherprice,Davidparrish,AllenGoldstein,JoyceHarris.2003.IncreasingbackgroundozoneduringspringonthewestcoastofNorthAmerica.GeOpHYSICALReSeARCHLeTTeRS,VOL.30,NO.12,1613,doi:10.1029/2003GL017024,2003
• Jiang,W.,Singleton,D.L.,Hedley,M.andMcLaren,R.,1997,SensitivityofozoneconcentrationstoVOC and NOx emissions in the Canadian Lower FraserValley,Atmosphericenvironment,31(4),627-638.
• Joe,H.,D.G.Steyn,ande.Susko,1996:Analysisof trends in tropospheric ozone in the Lower FraserValley,BritishColumbia.Atmosphericenvironment,30,3413--3421.
• Krzyzanowski,K.,I.G.Mckendry,J.L.Innes,2006:Evidence of elevated ozone concentrations on forested slopes of the Lower Fraser Valley, British Columbia,Canada.Water,AirandSoilpollution,173,273-287.
• MetroVancouver2012,2011LowerFraserValleyAirQualityMonitoringReportSummary.http://www.metrovancouver.org/about/publications/Publications/AmbientAirQuality2011.pdf
• McKendry,I.G.,Steyn,D.G.,Lundgren,J.,Hoff,R.M.,Strapp,W.,Anlauf,K.,Froude,F.,Martin,J.B.,Banta,R.M.andOliver,L.D.:1997,‘elevatedozone layers and vertical down-mixing over the LowerFraserValleyBC’,Atmos.environ.31,2135–2146.
• McKendry,I.G.2006.BackgroundConcentrationsofpM2.5andOzoneinBritishColumbia,Canada.Prepared for the British Columbia Ministry of environment,March2006.
• D.D.parrish,K.S.Law,J.Staehelin,R.Derwent,O.R.Cooper,H.Tanimoto,A.Volz-Thomas,S.Gilge,H.-e.Scheel,M.Steinbacher,ande.Chan,2012:Long-term changes in lower tropospheric baseline ozoneconcentrationsatnorthernmid-latitudes.AtmosphericChemistryandphysics,12,11485-11504.
2014 REGIONAL GROUND-LEVEL OZONE STRATEGY 19
• pottier,J.L.,H.p.Deuel,andS.C.pryor,2000:Application of the UAM-V and use of indicator species to assess control strategies for ozone reductions in the Lower Fraser Valley of British Columbia.environmentalMonitoringandAssessment,65,459--467.
• pryor,S.C.,I.G.McKendry,andD.G.Steyn,1995: Synoptic scale meteorological variability and surface ozone concentrations in Vancouver, BritishColumbia.JournalofAppliedMeteorology,34,1824--1833.
• pryor,S.C.andD.G.Steyn,1995:Hebdomadaland diurnal cycles in ozone time series from theLowerFraserValley,B.C.Atmosphericenvironment,29,1007--1019.
• pryor,S.C.,1998:Acasestudyofemissionchangesandozoneresponses.Atmosphericenvironment32,123--131.
• Reutenetal.2012.Basedonabstractonly.Impact of Climate Change on Ozone Pollution in the Lower Fraser Valley, Canada in Atmosphere-Ocean,50(1),42-53.NBmeteorologicalconsiderationsonly,emissionandbackgroundwereassumedtobesameasatpresent.
• StatisticsCanada.TheCanadianenvironmentalSustainability Indicators: On population-weighted ground-levelozone.2008.Availablefrom:http://www.statcan.gc.ca/pub/16-002-x/2008002/article/10624-eng.htm#a2
• Steyn,D.G.,M.Baldi,andK.Stephens,1996:Observation based analysis of photochemical smog in the Lower Fraser Valley using two analyticalschemesTech.Rep.Occasionalpaperno.41,DepartmentofGeography,TheUniversityofBritishColumbia.
• Steyn,D.G.,B.Ainslie,C.Reutenandp.L.Jackson.2013.Aretrospectiveanalysisofozoneformationin the Lower Fraser Valley, British Columbia, Canada.partI:DynamicalModelevaluation.Atmosphere-Ocean.51(2),153-169.
• Suzuki,N.M.,1997:ApplicationoftheUrbanAirshed Model in the Lower Fraser Valley, British Columbia,M.S.thesis,UniversityofBritishColumbia,Vancouver,B.C.,Canada,111pp.
• Tonnesen,G.S.andR.L.Dennis,2000:Analysisofradicalpropagationefficiencytoassessozonesensitivity to hydrocarbons and NOx 2: Long-lived species as indicators of ozone concentration sensitivity.JournalofGeophysicalResearch,105,9227--9241.
• UnitedStatesenvironmentalprotectionAgency.Integrated Science Assessment for Ozone and RelatedphotochemicalOxidants.2013.Availablefrom: http://www.epa.gov/ncea/isa/ozone.htm
• Vingarzan,R.andB.Taylor,2003:Trendanalysis of ground-level ozone in the Greater Vancouver/FraserValleyareaofBritishColumbia.Atmosphericenvironment,37,2159--2171.Vingarzan,R.(2004).Areviewofsurfaceozonebackgroundlevelsandtrends.Atmosphericenvironment,38;3431-3442.
• Vingarzan,R.andp.Schwarzhoff,DRAFT2008,‘OzoneTrendsandReactivityintheLowerFraserValley’.
• Vingarzanetal.2012.AirQualityObservationsattheAmphitritepointMarineBoundaryLayerSite.UBCCreateSymposium.December2012.
• WorldHealthOrganization.“Reviewofevidenceonhealthaspectsofairpollution–ReVIHAAp.”2013.Availablefrom:http://www.euro.who.int/en/health-topics/environment-and-health/air-quality/publications/2013/review-of-evidence-on-health-aspects-of-air-pollution-revihaap-project-final-technical-report
• WorldHealthOrganization.Healthrisksofozonefromlong-rangetransboundaryairpollution.2008.Availablefrom: http://www.euro.who.int/__data/assets/pdf_file/0005/78647/E91843.pdf
• Wu,S.,Mickley,L.J.Leibensperger,e.M.,Jacob,D.J.,Rind,D.,andStreets,D.G.,2008,effectsof2000-2050globalchangeozoneairqualityintheUnited States, Journal of Geophysical Research, 113(D06302),doi:10.1029/2007JD008917.
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