2. Nobody is spared !!!!!!!
That nasty cough is due to air pollution. You must stop flying
about over the cities of the world !!
3. Air Pollutants and its Effects
• Sulfur dioxide (SO2)
• Oxides of Nitrogen (NOx)
• Suspended Particulate Matter (SPM)
• Ozone (O3)
• Carbon monoxide (CO)
• Lead (Pb)
• Benzene (C6H6)
• Formaldehyde
• PAH
• Eye Irritation
• Nose Irritation
• Cough
• Cold
• Phlegm
• Breathlessness
• Chest Pain
• Bronchitis
• LBW
• Asthma (trigger)
• Lung cancer
4. Air Pollution Sources
• Vehicular Emissions
• Industrial Emissions
• Low grade cooking fuels
• Open garbage burning
• Dust particles present in the
atmosphere(Quarrying, construction)
• Environmental Tobacco Smoke (ETS)
5. Air Pollution Exposure
[Pyramid Model, American Thoracic Society, 1986]
Mortality
Proportion of the Population effected/exposed
Morbidity
Patho physiological Changes
Physiological changes
Pollution exposure
Adverse
Health
Effects
7. WHO and National (India)
air quality standards
Pollutant Sulfur dioxide Oxides of
Nitrogen
SPM
Residential and
sensitive areas 30 g/m3 30 g/m3 100 g/m3
8. Total # of vehicles in Mumbai
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
'81 '83 '85 '87 '89 '91 '93 '95 '97 '99 '01
Year
#
of
vehicles
9. Vehicle fleet in Mumbai(1981-1991)
0
50000
100000
150000
200000
250000
300000
350000
1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991
Year
Number
of
vehicles
Cars/Taxis Utility Vehicles Trucks/Busees Motor cycles Tricycles
10. Trends of air pollution in Mumbai,
1978-1999
0
50
100
150
200
250
300
350
400
1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1994 1995 1996 1997 1998 1999
Year
Levels
(m
eicrogram
/cubic
m
etr)
SO2 NO2 SPM
11. Air pollution levels in Mumbai,1994-96
Area
M
ankhurd
A
nik
Nagar
M
aravali
Chem
bur Naka
Borivali
M
ulund
Bhandup
G
hatkopar
Jogesw
ari
Saki Naka
A
ndheri
Khar
Sion
Sew
ree
Parel
Dadar
W
orli Naka
Babul Tank
Colaba
500
450
400
350
300
250
200
150
100
50
0
Mean SO2
Mean NO2
Mean SPM level
13. Air pollution in Control and Study areas, 1995
Control-Study areas
Chembur
Borivali
Mean
400
350
300
250
200
150
100
50
0
Mean SO2
Mean NO2
Mean SPM level
311
252
45
32 22
The difference is
significant at p<0.05
14. Monthly Trends of Air Pollution
in Mumbai,1994-96
Month
Decem
ber
Novem
ber
O
ctober
Septem
ber
A
ugust
July
June
M
ay
A
pril
M
arch
February
January
500
400
300
200
100
0
Mean SO2
Mean NO2
Mean SPM level
15. Seasonal levels of Air Pollution
in Mumbai,1994-96
Season
Monsoon
Summer
Winter
400
300
200
100
0
Mean SO2
Mean NO2
Mean SPM level
138
317
351
23
40
58
23
40
16. Percentage distribution of reported symptoms in
Control-Study areas of Mumbai.
Symptoms Control area
(367)
Study area
(478)
p value
Cough
Phlegm
Cold
Breathlessness
Allergy
Headache
Chest pain
2.5
1.4
13.1
5.7
2.7
1.9
3.0
5.4
4.6
13.6
6.9
6.7
4.0
6.7
0.031*
0.008**
0.826
0.486
0.008**
0.085#
0.015*
‘*’ p<0.05, ‘**’ p<0.005 and ‘#’ p~0.05 (marginally significant)
17. Effect of Exposure to air pollution on the
risk of air pollution related symptoms in
Control and Study areas
Symptoms$ β SE Exp(β)
Allergy#
(Control)
Study 0.884* 0.379 2.420
Chest Pain #
(Control)
Study 0.726* 0.371 2.066
# - Controlled for Age, Sex, Average Hours Spent in the Area, BMI and Smoking
() – Reference category
$ - The other symptoms such as cough, phlegm are not significant
‘*’ - p<0.05
18. Percentage distribution of History of
disease and Clinical diagnosis
Areas History of Disease* Clinical Diagnosis** Total
Normal MRAP MNRAP Normal MRAP MNRAP
Control
Study
88
81.4
5.7
9.0
6.3
9.6
74.4
62.1
19.1
30.5
6.5
7.3
367
478
‘*’ p<0.05 and ‘**’ p<0.0001
20. Impact of air pollution on the risk of having
air pollution related morbidity in
Control and Study areas (Clinical diagnosis)
Characteristics # β SE Exp(β)
Area
(Control)
Study 0.493** 0.185 1.673
‘**’ p<0.05
# Controlled for age, sex, average hours spent in the area, BMI and Smoking
() Reference Category
21. Vehicle fleet in Chennai
R2
= 0.9889
0
500000
1000000
1500000
2000000
2500000
3000000
19921993 199419951996 19971998 199920002001 20022003
Year
#
vehicles
22. Air pollution in Chennai, 2000-04
Area
ADR
ANR
VNR
TNR
KP
KVM
THR
MN
Mean
500
450
400
350
300
250
200
150
100
50
0
SO2 average
NOx average
PM average
Industrial
Commercial
Residential
23. Percentage distribution of reported symptoms in
selected areas of Chennai.
Symptoms Residential
(637)
Commercial
(801)
Industrial
(2242)
p value
Cough
Phlegm
Breathlessness
LBW
13.5
13.8
13.9
17.6
12.9
13.8
19.5
9.4
73.6
72.5
66.7
72.9
0.02*
0.007*
0.163
0.004*
‘*’ – Statistically significant
24. Over all respiratory symptoms in Chennai
Area Percent p-value
Residential 8.3
0.0005
Commercial 10
Industrial 16
25. Effect of Exposure to air pollution on the
risk of air pollution related symptoms in
Chennai
Symptoms β SE Exp(β)
Respiratory#
(Residential)
Commercial
Industrial
0.172
0.818***
0.209
0.178
1.188
2.267
Eye irritation #
(Residential)
Commercial
Industrial
-0.436
2.716***
0.611
0.419
0.647
15.122
# - Controlled for Age, Sex, Average Hours Spent in the Area, BMI and Smoking
() – Reference category
‘***’ - p<0.0001
26. Air pollution studies
• Mortality
– Total
– Cause specific (Air Pollution)
• Morbidity
– Hospital admissions
– Medication use
– Symptoms
– Pulmonary functions
– Subclinical measures
27. Air pollution study designs
• Observational
– Ecological
– Case-Control
– Cross-Sectional
– Cohort
– Panel
– Time series analysis
– Case-Crossover
29. Pros and Cons of type studies
Type of study Advantages Disadvantages
Toxicological Can determine if effect exists
Specific dose known, study toxins
Can observe cellular and other changes,
and explore mechanisms
Extrapolation from animal to human
Extrapolation from high dose to low
Limited sample size
Acute effects only
Human Clinical Determine if effect exists in humans
Specific dose known
No need to extrapolate to humans
Limited sample size, subgroups
Only acute effects
Epidemiological No need to extrapolate
Less expensive
Can examine a wide range of exposures,
outcomes and subgroups
Can examine pollutant mixtures,
interactions
Imprecision in measurement of
exposure and response
Potential for confounding
Limited endpoints
Possibility of spurious findings
Difficult to elicit mechanisms
30. Findings
• Population is on the rise
• Greater stress on the urban resources and transportation
of all types and modes
• Growing number of vehicle fleet and pollution
• Scrubbing effect of rains - To some extent
• Seasonal and monthly variation of pollution
• Significant health differentials in the control and study
areas in MRAP (both history and clinical diagnosis)
• Better Pulmonary Function Test (PFT) values in control
area
31. Comparative Risk Assessment (CRA)
• Systematic way of looking at environmental
problems
• Combines information on the inherent
hazards of pollutants, exposure levels and
population characteristics to predict
resulting health effects
• Uses data from available sources
• Rapid,inexpensive
• Identifies most significant health problems
32. Recommendations
• Industries should control the emissions
• Near the industries, the residential colonies should be
sparse
• Traffic should be regulated to reduce the stagnation
and bottle necks have to be cleared
• Two/three wheelers should be upgraded to four-stroke
engines
• Constructing and improving mass-transit systems to
reduce the need of the personal transportation
33. Stake Holders in the Clean Environment
CLEAN AIR
NGOs
Community
groups
Awareness
Government Industry
Research
Institutes
Judiciary
International
Organizations
34. Future Research
• Time series analysis of morbidity, mortality
and pollution levels
• All morbidity and all mortality from
corporation and hospitals
• Confounders
• Siting of monitors
• Maximum and uniform measurements
35. Summary
• Growing population and vehicles
• Air pollution is on the rise
• Health differentials
• Air pollution related morbidity
