Air Science Policy: The US Perspective on Adressing Future Air Quality Challenges - C Arden Pope III
Air Science Policy: The U.S. Perspective onAddressing Future Air Quality ChallengesC. Arden Pope IIIMary Lou Fulton Professor of EconomicsPresented at:Air Science Policy ForumDublin, IrelandApril 15, 2013
Early “Killer smog” episodes demonstrated that air pollution at extremelevels can contribute to respiratory and cardiovascular disease and deathDec. 5-9, 1952: London--1000’s of excess deathsDec. 1-5, 1930: Meuse Valley, Belgium60 deaths (10x expected)Oct. 27-31, 1948: Donora, PA20 deaths, ½ the town’s population fell illRespiratory and cardiovasculardisease and death
The killer episodes spurred air pollution policies in the U.S.Killer Smog(and related research)Public Policy Results1955-1967: Air pollution controlacts1967, 1970: Clean Air Act,Major Amendments, NationalEnvironmental Policy Act1977 & 1990: MajorAmendments to Clean Air Act1980’s: Elimination ofextreme “Killer Smog”episodes & Improved airquality1930: Meuse Valley, Belgium1948: Donora, PA1952: London, EnglandBy the 1980’s, many thought the air pollution problemhad been solved…
…but by the early 1990’s, several studies suggestedthat even moderate levels of air pollution couldcontribute to significant health effects.
Utah Valley, 1980s• Winter inversions trap local pollution• Natural test chamber• Local Steel mill contributed ~50% PM2.5• Shut down July 1986-August 1987• Natural Experiment
Large difference in air qualitywhen inversions trap air pollution in valleyUtah Valley: Clean dayUtah Valley: Dirty day(PM10 = 220 mg/m3)
mg/m3/NumbersofAdmissions050100150200250300PM10 concentrations Childrens respiratory hospital admissionsMean PM10levels forMonthsIncludedMean HighPM10levels forMonthsIncludedPneumoniaandPleurisyBronchitisandAsthmaTotalChildrens Respiratory Hospital AdmissionsFall and Winter Months, Utah ValleySources: Pope. Am J Pub Health.1989; Pope. Arch Environ Health. 1991When the steel mill was open, total children’s hospitaladmissions for respiratory conditions approx. doubled.mg/m3/NumbersofAdmissions050100150200250300PM10 concentrations Childrens respiratory hospital admissionsMean PM10levels forMonthsIncludedMean HighPM10levels forMonthsIncludedPneumoniaandPleurisyBronchitisandAsthmaTotalChildrens Respiratory Hospital AdmissionsFall and Winter Months, Utah ValleySources: Pope. Am J Pub Health.1989; Pope. Arch Environ Health. 1991MillOpenMillClosed
%increaseinmortality0123Estimates frommeta analysisEstimates from Multicity studies29cities(Levyetal.2000)GAM-basedstudies(Stiebetal.2002,2003)Unadjusted(Andersonetal.2005)6U.S.cities(KlemmandMason2003)8Canadiancities(BurnettandGoldberg2003)9Californiancities(Ostroetal.2006)10U.Scities(Schwartz2000,2003)14U.Scities,case-crossover(Schwartz2004)NMMAPS,20-100U.S.cities(Dominicietal.2003)APHEA-2,15-29Europeancities(Katsouyannietal.2003)9Frenchcities(LeTertreetal.2002)13Japanesecities(Omorietal.2003)NonGAM-basedstudies(Stiebetal.2002,2003)Publicationbiasadjusted(Andersonetal.2005)7Koreancities(Leeetal.2000)20g/m3PM1020g/m3PM1020g/m3PM1020g/m3PM1020g/m3PM1010g/m3PM2.520g/m3PM1010g/m3PM2.510g/m3PM2.520g/m3PM1020g/m3PM1020g/m3PM1020g/m3BS40g/m3TSP20g/m3SPMReviewofAsianLit.--8studies(HEIReport,TableTS2)20g/m3PM1020g/m3PM1020g/m3PM10Estimates frommeta analysisfrom Asian LitPAPAStudies--4studies(HEIReport,TableTS2)AsianLit.incorporatingPAPAstudies(HEIReport,TableTS2)18LatinAm.studies(PAHO2005)20g/m3PM1010 mg/m3 PM2.5 or 20 mg/m3 PM10 → 0.4% to 1.5%increase in relative risk of mortality—Small butremarkably consistent across meta-analyses and multi-city studies.Daily time-series studies ***of over 200 cities***
• Case-crossover study of acute ischemic coronaryevents (heart attacks and unstable angina) in 12,865cardiac patients on Utah’s Wasatch Front• Patients underwent coronary angiography• Results showed associations between air pollution andcardiovascular disease2006;114:2443-48Evidence mounted suggesting that air pollution has significantimpacts on cardiovascular health.
%-10.00-5.000.005.0010.0015.0020.00Figure 2. Percent increase in risk (and 95% CI) of acute coronary events associated with10 mg/m3of PM2.5, stratified by various characteristics.AllacutecoronarySubsequentMIUnstableAnginaAge<65Age>=65MaleFemaleSmokingNonSmokingBMI<30BMI>=30CHF,yesCHF,noHypertension,yesHypertension,noHyperlipidemia,yesHyperlipidemia,noDiabetes,yesDiabetes,noFamilyhistory,yesFamilyhistory,no# ofDiseasedVessels# ofRisk Factors012301234+IndexMIJust a few days of PM exposure significantly increasedrisk for heart attacks and ischemic heart disease.
Short-term changes in air pollution exposureare associated with:• Daily death counts (respiratory and cardiovascular)• Hospitalizations• Lung function• Symptoms of respiratory illness• School absences• Ischemic heart disease• Etc.
Longer-term air pollution exposure hasbeen linked to even substantially largerhealth effects.
Median PM2.5 for aprox. 19808 10 12 14 16 18 20 22 24 26 28 30 32 34AdjustedMortalityfor1980(Deaths/Yr/100,000)6006507007508008509009501000Age-, sex-, and race- adjusted population-based mortality rates in U.S. cities for 1980plotted over various indices of particulateair pollution (From Pope 2000).
Methods:• 14-16 year prospective follow-up of 8,111 adults living in six U.S. cities.• Monitoring of TSP PM10, PM2.5, SO4, H+, SO2, NO2, O3 .• Data analyzed using survival analysis, including Cox Proportional Hazards Models.• Controlled for individual differences in: age, sex, smoking, BMI, education, occupationalexposure.An Association Between Air Pollution andMortality in Six U.S. CitiesDockery DW, Pope CA III, Xu X, Spengler JD,Ware JH, Fay ME, Ferris BG Jr, Speizer FE. 1993In 1993, the Harvard “Six-Cities” study was published.It followed > 8,000 adults for 14-16 years to observeassociations between air pollution and risk of death.
Adjusted relative risk of dying werealmost linearly associated with air pollution.
Increased levels of fine PM increased risk of death.
Air pollution is most strongly associated with deaths fromischemic heart disease, dysrhythmias, heart failure, cardiacarrest and related heart disease.RR(95%CI)0.650.700.750.800.850.900.951.001.051.101.188.8.131.521.351.40AllCardiovascularplusDiabetesIschemicheartdiseaseDysrhythmias,Heartfailure,CardiacarrestHypertensivediseaseOtherAtherosclerosis,aorticaneurysmsCerebro-vascularOtherCardio-vascularDiabetesRespiratoryDiseasesCOPDandalliedconditionsPneumonia,InfluenzaAllotherrespiratory2004;109:71-77.John GodleskiRisk ratios fordeathassociatedwith a 10 µg/m3change in PM2.5Dot sizesindicate thenumber ofdeaths for eachcause.
The Six-Cities and ACS studies have undergoneextensive peer review and analyses. Their resultsare reproducible and remarkably robust.
Legal uncertainty largelyresolved with 2001unanimous ruling by theU.S. Supreme Court.
Percentincreaseinmortalilyrisk(95%CI)-100102030405060708090100110120180190All Cause CPD CVD IHDU.S. Medicare Cohort studies:•Eftim et al. Epidemiology 2008•Zegar et al. EHP 2008Cohorts of Medicare participants cities of the 6-cities and ACS study, plus all U.S.U.S. Medicare Cohort Studies
Modern air pollution science has resulted in new and tighterstandards in the U.S. for air pollution—especially PM2.5ContemporarySciencePublic Policy Results1997: New PM2.5 standards(24-hr 65 µg/m3,annual 15 µg/m3)2006: PM2.5 24-hr standardrevised (35 µg/m3)2012: PM2.5 annual standardrevised (12 µg/m3)1990 - 2013: Continuedgeneral improvements inair quality1989+ Time-series studies1993+ Prospective cohortmortality studies1997+ 100’s of otherincluding tox.,clinical, etc.
So, an obvious question—Has reducing air pollution resulted insubstantial and measurableimprovements in human health?
- Matching PM2.5 data for1979-1983 and 1999-2000 in51 Metro Areas- Life Expectancy data for1978-1982 and 1997-2001 in211 counties in 51 Metro areas- Evaluate changes in LifeExpectancy with changes inPM2.5 for the 2-decade periodof approximately 1980-2000.Fine-Particulate Air Pollution and LifeExpectancy in the United StatesC. Arden Pope, III, Ph.D., Majid Ezzati, Ph.D., and Douglas W.Dockery, Sc.D.January 22, 2009Do cities with bigger improvements in air quality have biggerimprovements in health, measured by life expectancy?
Reduction in PM2.5, 1980-20000 2 4 6 8 10 12 140.0Reduction in PM2.5, 1980-20000 2 4 6 8 10 12 14ResidualchangesinLEcontrollingforcovariates-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.52247494541017194648643502421368342072511112144451273 28303213182692923373840153352353116394142BYES. On average, the greater the reduction in airpollution, the greater the increase in life expectancy.
Finally,This stylized approach ignores various uncertainties andcomplications including: Interactive multi-pollutants, Issues of environmental justice, How do efforts to reduce traditional air pollutantscomplement or diverge from efforts to address climatechange and is there a reasonable way to integrate theseefforts.Thank you.