long term effects of air pollution on health. peter burney. king’s college london
TRANSCRIPT
Long term effects of air pollution on health.
Peter Burney.
King’s College London
Breathlessness by night or day by annual mean PM10 (Sepaldia)
• Selected symptoms associated with measures of air pollution
• Some correlations work out better than others
Proportion of the non-smoking population with FVC < 70% by TSP (NHANES)
• Continuous increase in poor lung function as particulate levels rise.
• Adjusted for age, height, sex, race, obesity, occupation, temperature, income and region
The Meaning of Chronic Morbidity
• Repeated acute effects?
• Change in susceptibility?
• Irreversible changes?
1
1.1
1.2
1.3
1.4R
elat
ive
Ris
k
20 40 60 80 100 120
PM10 cutoff g.m-3
Risk of developing symptoms of airways obstructive diseaseaccording to hours/year exposure to different levels of PM10
250hrs
500hrs
1000hrs
2500hrs
5000hrs
0
10
20
30
40
Pre
vale
nce
of r
espi
rato
ry s
ympt
oms
<30 30-60 >60
SMOKE (g/m3)
Smoke and symptoms in schoolgirls, UK 1981
3 or more
1 or more
-30
-20
-10
0
10
Net
cha
nge
in R
espi
rato
ry S
ympt
oms
(%)
0 -1.4 -35.9 -49.8 -58.9
Smoke Change (g/m3)
Longitudinal analysis of symptoms and smoke pollutionin British schoolgirls 1973-1974 (Melia et al. 1981)
Changes in lung function in different communities (Tashkin 1994)
Relative decline in FEV1 (ml)
TSP (mg/m3) MEN WOMEN
Lancaster 85 0 0Long Beach 101 -18.4* -15.6**Glendora 133 -26.5** -16.2**
Adjusted for age, height, initial FEV1, allergy and smoking*p<0.01; **p<0.001
Differences in lung function growth between ‘polluted’ and ‘unpolluted’ areas
(from Jedrychowski, et al. 1999)
Boys (95% CI) Girls (95% CI) FVC (ml/yr) -101 (-206, 4)+ -125 (-231,-19)*
FEV1 (ml/yr) -154 (-264,-44)* -142 (-259,-25)*
+p=0.09 *p=0.02
Factors predicting adult respiratory disease in the 1946 national birth cohort (Mann et al, 1992)
Wheeze/Asthma
LowerRespiratoryDisease
Phlegm PEFR
EARLY LIFE FACTORS
LRI before 2 yrs 6.1 4.1 4.7 0.8Bronchitis inparents 6.6 3.4 6.2 1.9Poor homeconditions 10.0 6.2 12.5 8.8Pollution 0-2 yrs 3.8 3.1 0.5 0.1Pollution 2-11 yrs 4.5 3.2 3.1 0
LATER FACTORS
Smoking 20.2 9.0 23.5 0Asthma - 2.8 4.4 0
SMR from bronchitis related to area based infant mortality from LRTI
• Area SMR from bronchitis is associated with infant mortality from pneumonia 70years earlier.
0
1
2
3A
dult
FE
V1
(litr
es)
<5.5 -6.5 -7.5 -8.5 -9.5 >9.5
Birth weight (lbs)
Relation of adult FEV1 to Birthweightand smoking(Barker et al., 1991)
Never smokers
Ex-smokers
current
0
0.5
1
1.5
2
2.5
3
Adu
lt F
EV
1 (l
itres
)
<5.5 -6.5 -7.5 -8.5 -9.5 >9.5
Birth weight (lbs)
Relation of adult FEV1 to birthweight andbroncuitis or pneumonia in infancy
(Barker et al. 1991)
ALRI in infancy
No ALRI in infancy
0
20
40
%
LOW HIGH
Air Pollution
Chest disease before 2 years by air pollution level (1946 birth cohort)
Possible causes of inconsistency
• Various outcomes• Various exposures• Modifying factors• Measurement errors
• Bronchitis• COPD• Allergy• Asthma• Cancer• Early infection• Premature birth
Possible causes of inconsistency
• Various outcomes• Various exposures• Modifying factors• Measurement errors
• Particles • SO2• NO2• Oxidants• ‘Traffic’• Diesel
Lorry traffic affects infant lung disease in
metropolitan but not urban or rural areas (Ciccone et al., 1998)
Effect of lorry traffic on early respiratory disease
0
0.5
1
1.5
Daily lorry transit
Rel
ativ
e ris
k
Urban/rural
Metropolitan
Effect of supplementing cyclists with antioxidants on the respiratory response to ozone (from
Grievink et al. 1998)
Treatment Control Treatment effect
Mean (sem) Mean Sem Difference (95% CI)
FVC 0.25 0.24 -1.83 0.49 2.08 1.31,2.85
FEV1 -0.20 0.60 -1.86 0.49 1.66 0.62,2.70
PEF 1.48 3.04 -5.35 2.03 6.83 3.17,10.49
MMEF -0.51 0.93 -0.93 0.94 0.42 -1.38,2.22
Prospects
•The evidence is currently descriptive.•The evidence is reported inconsistently.•There is likely to be reporting bias.•Much of the data refers to pollution patterns that are now largely historic.
ECRHS II
• A follow-up of subjects studied in ECRHS I
• A study of many different protocols linked to studying aetiology and prognosis
• Principal outcomes relate to atopy, asthma, lung function and bronchial hyper-responsiveness
• Some specific protocols on air pollution
ECRHS II centres
ECRHS II pollution protocols
• Historic review of air pollution data• Measurement of PM2.5 in all centres• Analysis of PM2.5 for metal content• Measurement of dust mite allergen from beds• Measurement of NO2 from kitchens, outside
kitchen windows and at central monitor in selected centres
NO2 arithmetic annual mean 1999
29
32
27 28
303029
27252524
1817
10
34 34 35
50 50 50 51 52
66
0
10
20
30
40
50
60
70
GALDAKAO
ALBACETE
HUELVA
DundeeTar
tuPorto
GOTEBORG
BASEL
BARCELONA
Vienna
Montp
ellie
r
Cambrid
ge
GELEEN
Hamburg
GRENOBLE
BERGEN
PAVIA
ANTWERP
TURIN
Coimbra
PARIS
Athen
s
Dublin
g/m3
Traffic stations
Background stations
PM 10 annual arithmetic mean 1999
29
13
16
21 22 2223
25
32
42
49
2828
0
10
20
30
40
50
60
g/m3
Background stations
Traffic stations
ECRHS II
Analysis principally relates to the natural history (incidence, remission and modification of disease over
time) of asthma, atopy, lung function, and airway responsiveness.
ECRHS II
The major strengths of the study are its size, the diversity of the environments studied, the extent of
the potential confounders being assessed.