question of the authorities of austria, france, & switzerland:
DESCRIPTION
Question of the Authorities of Austria, France, & Switzerland: What are the health costs of traffic-related air pollution ?. UNECE1.ppt. Requires interdisciplinary approaches. Air pollution concentrations Air Hygiene Population exposure distribution GIS - PowerPoint PPT PresentationTRANSCRIPT
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Question of the Authorities of
Austria, France, & Switzerland:
What are the health costs of traffic-related air pollution ?
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Requires interdisciplinary approaches
Air pollution concentrations Air Hygiene
Population exposure distribution GIS
Exposure - Response function Epidemiology
Derivation of attributable cases Epi Risk Assess.
Costing Economy
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Uncertainties
– multiple sources of uncertainties
– majority: not statistical uncertainties
– conceptual and data uncertainties
– gaps at interdisciplinary interface
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• “At least” approache
• with risk function based 95% CI
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Definition of Air Pollution Exposure
– Availability of effect functions
– Availability of exposure data
– no multiple counting (correlated pollutants; same sources)
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PM10 „at least“
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Selected Attributable Health outcomes
Attributable DeathLong-term effect
Hospital admissions (cardio-resp.) Short-term effect
Chronic bronchitis incidence (adults) Long-term effect
Bronchitis episodes (children) Short-term effect
Restricted activity daysShort-term effectAsthma attacks (children & adults) Short-term effect
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Impact Assessment Model
Exposure-response function
PM10
# Death
Attributable death
PM10 reference
7.5 ug/m3
„at least“
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Exposure-Response Functionfor Mortality
Weighted average of :
– ACS-Study (Pope et al., 1994)
– Harvard 6-City Study (Dockery et al, 1993)
• 4.3 % (95% CI: 2.6-6.1%) increase per 10 g/m3 PM10
• ~ 360 (200-520) attributable death per 10 g/m3 PM10 and 1 Mio. inhabitants
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Frequency distribution of total PM10 population exposure
0%
10%
20%
30%
40%
50%
60%
0 - 5 5 - 10 10 - 15 15 - 20 20 - 25 25 - 30 30 - 35 35 - 40 40 - 45 45 -50 > 50
PM10 concentration (g/m3, annual mean)
Pop
ula
tion
%
Austria France Switzerland
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Air Pollution Attributable Death in Austria, France and Switzerland
Attributable Death (adults 30 yrs.)
Total # cases: 40‘600 (24‘600-56'900)
or: ~ 6% (3.6-8.4%) of total deaths
Traffic related: 21’800 (13’300- 30’600)
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See: Sommer et al, in OECD Report: Ancillary Benefits and Costs of Greenhouse Gas Mitigation, New York; 2000
Monetarization of attributable death in the Trinational Study
source: Willingness-To-Pay estimates
value: 900‘000 EUR per statistical fatality
total: 36.5 Mio. EUR
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Air pollution related health costs ~ 50‘000 Mio. EUR per year
traffic related: ~ 27‘000 Mio EUR per year
6% 1%0%0%
73%
20%
mortality (long-term) chronic bronchitisrestricted activity days hospital admissionsacute bronchitis asthma attacks
6%
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Key Outcome Uncertainties
1) Why cohort study estimates?
2) Attributable death and life time lost
3) Are US-Studies relevant for Europe?
4) Are effects source specific?
5) Are “attributable” death “preventable”
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1) Why Cohort study based Attributable Death ?
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OR:
Why not time-series based estimates, which are 5-10 times smaller ?
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Frailty and Death
Frailty(susceptibility for death)
TimeBirth
Death
Age at death
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Frailty and Exposure
Frailty(susceptibiltiy for death)
TimeBirth
Death
Age at deathStart smoking
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Contribution of Air Pollution
Frailty(susceptibility for death)
TimeBirth
Death
Age at death
SMOG EPISODE
Cumulative exposure
Chronic Bronchitis
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Focus of the Time-series analysis
Frailty(susceptibilty for death)
TimeBirth
Death
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Time-series: counting advancement of death
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Period of exposure
Time
Time to event
Period of events
Death counts
Pollution
SHORT PERIODSSHORT PERIODSSHORT PERIODSSHORT PERIODSSHORT PERIODS
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Time-series
• 1) Time-series captures – short-term effects only– not all short-term effects
• 2) Life time lost not known
> > incomplete impact assessment
• 3) Long-term effect on life shortening not measured
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Focus of the Cohort Study
Frailty(susceptibilty for death)
TimeBirth
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Cohort studies
• capture cumulative total effects on time to death
> more complet counting of effects
BUT:• no distinction of acute and long-term • only US studies• YoLL not published /QALY not assessed
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Long-term and short-term cases(Künzli et al, Am J Epidemiol 2001 in press, adapted from COMEAP, 1998)
All Death
long-term effect
short-term effect
All Air Pollution cases
Mixed effects
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2) Number of deathversus years of life lost
Both:
• Life expectancy in a population • annual number of deaths
depend on:
age specific death ratesage specific death rates
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BUT:
published are only number of deaths !
Indirect estimates of years of life lost:
• life table approache• assumptions about age structure of
cases
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Mortality in the Trinational Study
1) Direct estimates of „attributable death“ ( > age 30; non-violent death)2) Years of life lost: • Indirect estimates, used for costing• assumptions:
– the attributable death are due to cardiopulmonary causes– same age distribution as all cardiopulmonary death– thus: typical age of an „air pollution death“ ~75-80 yrs.
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Average reduction in population life expectancy
For a population with a 10 g/m3 higher PM10
Sommer et al. (Trinational Study): ~0.5 yr
other estimates: ~6 mo. to ~2 yrs.
(Brunekreef; Pope; Leksell; Hurley; Miller; Rabl etc.)
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3) We transfered the US cohort results to Europa !
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• Consistency for other outcomes between US and European countries
• Coherence between different outcomes
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Mortality (adjusted Relative Risk) and long-term mean pollution (PM2.5)
Harvard Six-City Cohort Study, Dockery et al, NEJM 1993; 329 (24):1753-9
1.00
1.05
1.10
1.15
1.20
1.25
1.30
0 10 20 30 40
Rel
ativ
e R
isk
mean PM2.5UNECE.ppt
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Annual mean PM10 and expiratory capacity (FVC) in the 8 SAPALDIA areas
Ackermann-Liebrich et al, AJRCCM 1997; 155 (1):122-129
-6
-4
-2
0
2
4
6
0 10 20 30 40
PM10 annual mean (g / m3)
FV
C
% d
evia
tio
n f
rom
pre
dic
ted
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Other Evidence?
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Europe French PAARC suggestive abstractDutch cohort suggestive abstractSAPALDIA ?? Needs other 10 yrs.ECRHS ?? ?
USA: Abbey et al 1999 interaction with sex?Krewski et al 2000 interaction with SES?
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4) Are attributable death source specific?
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Assumption in tri-national study:
• PM10 effects are independent of PM source• -> one single effect slope
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Percent Change (and 95th CI) in Daily Death per 10 g/m3 PM2.5 mass an source specific elements
1979-1988, Harvard Six Cities; Laden et al, Env Health Perspect 2000; 108 (10): 941-947
3.4
1.1
-2.3
1.6
-6
-4
-2
0
2
4
6
low
mean
highPM2.5 mass
Crustal (Si)
Motor (Pb)
Coal (Se)
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Percent Change (and 95th CI) in Daily Death per 10 g/m3 PM2.5 mass an source specific elements
1979-1988, Harvard Six Cities; Laden et al, Env Health Perspect 2000; 108 (10): 941-947
3.4
1.1
-2.3
1.6
-6
-4
-2
0
2
4
6
low
mean
highPM2.5 mass
Crustal (Si)
Motor (Pb)
Coal (Se)
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Percent Change (and 95th CI) in Daily Death per 10 g/m3 PM2.5 mass an source specific elements
1979-1988, Harvard Six Cities; Laden et al, Env Health Perspect 2000; 108 (10): 941-947
3.4
1.1
-2.3
1.6
-6
-4
-2
0
2
4
6
low
mean
highPM2.5 mass
Crustal (Si)
Motor (Pb)
Coal (Se)
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Percent Change (and 95th CI) in Daily Death per 10 g/m3 PM2.5 mass an source specific elements
1979-1988, Harvard Six Cities; Laden et al, Env Health Perspect 2000; 108 (10): 941-947
3.4
1.1
-2.3
1.6
-6
-4
-2
0
2
4
6
low
mean
highPM2.5 mass
Crustal (Si)
Motor (Pb)
Coal (Se)
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5) Are „attributable death“ also „preventable death“?
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Unknown time domaines
Duration of ‘long-term’ exposure
Relevant time window of exposure
Time between exposure and effect
Time between intervention and benefit?
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Time-to-Benefit (death, long-term)(Sommer et al., 1999)
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Attributable Costs
Time (yrs)Clean air intervention
10 20
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Competing risks
Removal of one long-term health risk factor will modify the importance of the remaining risks
“attributable death” > “preventable death”
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TSP decrease and reduction in bronchitis prevalence (Germany, 1993 versus 1995, children, age 5-14 yrs)
30 40 50 60 70annual mean of TSP g/m3
30
40
50
60
70b
ron
chiti
s p
reva
len
ce (
%)
19931995
Year:
Hettstedt
Bitterfeld
Zerbst
(Heinrich et al, AJRCCM 2000; 161:1930-36)COP6DenHaag.ppt
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5 10 15 20 25 30 35Jahresmittel PM10(g/m3)
5
7
9
11
13
15
17
19
21
23
25
Montana
Payerne
Langnau
Rheintal
Biel
Lugano
Genf
ZürichBern
Anières
Annual mean PM10 g/m3
Acute bronchitis in children and annual mean PM10
The SCARPOL Study
C. Braun-Fahrländer; AJRCCM 1997UNECE.ppt
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Conclusion
• Air pollution accounts for 4-8% of death
• “Attributable death” from cohorts: adequate approache
• BUT: gaps in evidence and uncertainties: • Best effect estimate?• Years of life time lost?• European long-term studies?• Source attribution ?• How many are “preventable death”? When?
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Susceptibility and Time-to-event
Probability of
event
Time
•High susceptibility•Early response
•Low susceptibility•Late response
Exposure