Transcript An Epidemiological Study on effects of air pollutants on

An Epidemiological Study on
Effects of Air Pollutants on
Respiratory Morbidity among
Adults
By
MANOJ KUMAR
Guides
Prof. Rajesh Kumar
Prof. S.K. Jindal
Dr. Madhu Khullar
Air pollution is causing immense concern in India.
Ambient Air Quality in Major Cities During 2002
STATE/CITY
RSPM
SPM
Hyderabad
Delhi
Ahmedabad
Banglore
Mumbai
Chennai
Kolkata
High
Critical
Critical
High
High
Moderate
Critical
High
Critical
Critical
High
Critical
Moderate
Critical
Pollution level
RSPM
SPM
Low (L)
0-30
0-70
Moderate (M)
30-60
70-140
High (H)
60-90
140-210
Critical (C)
>90
>210
Effect of London Smog
Acute Effects of Air Pollution
Authors
Place
Effects
Schwartz et al.,1992
London
Increase in particulate of 100 g/m3 was associated with 7%
increase in mortality.
Schwartz,1993
Southern U.S.
1.1 RR was estimated for 100 g/m3 of inhalable particles
levels.
Sunyer et al., 1993
Barcelona
An increase of 25 g/m3 in SO2 produced 6 to 9% change in
emergency room admissions for COPD.
Burnett et al., 1995
Ontario
Canada
A 13 g/m3 increase in sulphates was significantly associated
with 3.7% increase in respiratory and 2.8% increase in cardiac
admissions.
Damia et al., 1999
Spain
There were approximately 3.5 admissions a week per 34.6
g/m3 change in black smog.
Pande et al., 2002
AIIMS,
New Delhi
Acute coronary events to the emergency room admissions
increased by 24.3% with increase in air pollution more than
permissible limits.
Chronic Effects of Air Pollution
Authors
Place
Effects
Deteles et al., 1987
Los Angeles
Association between PM10 Level & increase in symptoms of
respiratory diseases.
Spektor et al., 1988
New Jersey
Daily O3 exposure & humidity were the most explanatory
variable for change in lung functions.
Ostro et al., 1991
Denver
Cough was associated with foreign particles & shortness of
breath.
Wong et al., 1999
Hong Kong
Living in the polluted area was associated with poor
respiratory health.
Zamp et al., 1999
Switzerland
NO2, TSP, PM10 was significantly associated with the reported
prevalence of cough or phlegm and breathlessness.
Peter et al., 1999
California
Wheeze prevalence was associated with levels of SO2 and
NO2.
Frischer et al., 1999
Germany
Long term ambient ozone exposure might negatively
influence lung function growth.
Kamat et al., 1992
Bombay
Respiratory symptoms were higher in the polluted area i. e.,
cough 12% and dysponea 17%.
Chhabra et al., 2001
New Delhi
Chronic cough, chronic phlegm & dysponea were significantly
common in higher pollution zone, bronchial asthma, COPD &
lung function were better in low pollution zone.
Aim
The study was aimed to evaluate effects of air
pollutants on respiratory morbidity among adults
Objectives
To monitor ambient air quality.
To estimate the prevalence of respiratory
morbidity and lung functions.
To determine association between air
pollution and respiratory morbidity.
Material And Methods
Study Design-Cross-sectional study.
Household survey for morbidity.
Ambient air quality monitoring.
Study Area
Mandi Gobindgarh
Mandi
Gobindgarh
Morinda
Study area
Reference
area
Area of 32
Km2
Area of 7 km2
Population
55,400
Population
21,800
Steel rolling
mills and
foundries.
One sugar
mill only.
Morinda
Sampling Sites
Mandi Gobindgarh Morinda
Guru ki Nagri
Rest House Colony
Prem Nagar
Purana Bazar
Sampling Site
Map of Mandi Gobindgarh
Map of Morinda
Guru ki Nagri
Prem Nagar
Site 2 - Purana Bazar
Site No. 1 - Rest House Colony
D
USEROA
O
H
ST
E
R
REST HOUSECOLONY
GURU
PURANA BA
CHOCKBAZA
CHANDIGARH
Cluster Sampling
Random selection of household
and then next nearest household
till 500 individuals enrolled from
each of study site.
Sample Design
Age Groups
(years)
20-29
Male
Female
100
100
30-39
100
100
40-49
100
100
50-69
100
100
70+
100
100
Total
500
500
Study Tools
 Questionnaire
Respiratory symptoms and diseases,
SES (Kuppuswami scale),
Household environment,
Smoking history,
Occupational history
 Physical Examination
Height (cm.)
Weight (kg.)
Spirometery by portable ventilometer
FVC, FEV1, PEFR, FEV1/FVC%
Exposure Monitoring
 Air Sampling-weekly for two years
SPM, NOx, SOx, O3
High Volume Air Sampler
Twelve hourly
CO
Organic Vapors Sampler
Eight hourly
 Meterological data
Wind velocity,
Temperature
and humidity
Data Collection
Eligible population
Mandi Gobindgarh
Morinda
Male
(N=535)
(%)
Female
(N=523)
(%)
Male
(N=524)
(%)
Female
(N=520)
(%)
Interviewed
Non-Respondents
Refused
Old age
Mentally retarded
Away from their family
93.8
95.8
95.6
96.1
2.4
0.4
0.2
2.0
-
1.2
0.3
-
2.6
-
Spirometery
Non-Respondents
Old age
Refused
Mentally retarded
Paralysis
Inability to stand
90.8
90.4
91.6
94.3
1.4
3.2
0.6
-
0.2
4.6
0.6
1.0
1.8
0.4
0.4
0.6
2.9
-
Variable Definitions
 Cough: If an individual usually coughs from
his/her chest first thing in the morning.
 Phlegm: If an individual usually bring up
phlegm from his/her chest first thing in the
morning.
 Dysponea: Shortness of breath when
walking up a slight hill or others people of
his/her age on the level ground or at his/her
own pace on level ground or bath, washing or
dressing .
 Wheezing: Whistling sound while breathing.
 Chronic bronchitis: If an individual usually
has any cough or sputum from his/her chest
during the day or night, twice or more, in
winter for more than three months in a year,
for two consecutive years.
 Overcrowding: The degree of overcrowding
can be expressed, as the number of persons
per room, i.e., number of persons in the
household divided by the number of rooms in
the dwelling.
 Year Of Residence: Those who were
residing in the town for less than 10 years
and others for more than 10 years in the
town.
Dust Exposure At Place of Work
 Mild: idle, shopkeepers, businessmen,
secondary education teaching professionals,
clerks, sales retail assistants, tailor etc.
 Moderate: goldsmith, cobbler, electrician,
fitter, heavy good vehicle driver, house
keeper, halwai, maid servant, farmer, dhaba
worker or those who are taking care of
animals.
 Severe: smiths and forges, sheet metal
workers, labours in other construction modes,
labour in building and wood working, road
sweeper, cleaners, motor mechanics, petrol
pump worker.
Algorithm For Interpretation Of Spirometry Data
Comparison of FEV1/FVC to its LLN
FEV1/FVC  LLN for FEV1/FVC
FVC  LLN for FVC
FEV1/FVC < LLN for FEV1/FVC
FVC <LLN for FVC
NORMAL STUDY RESTRICTIVE DEFECT
OBSTRUCTIVE DEFECT
Categorize Using FVC
Categorize Using FEV1
Mild
FVC >60%
Moderate FVC 40-60%
Severe
FVC <40%
Mild
FEV1 >60%
Moderate FEV1 40-60%
Severe FEV1 <40%
Statistical Analysis
Concentration of SPM, SOx, NOx, CO and O3
was summarised as means and standard
deviation.
Prevalence of respiratory symptoms &
spirometric airflow limitation
Chi-square test
Student’s t-test
Mantel-Haenszel summary odds ratio
Logistic regression analysis
Interaction between the air pollution and
smoking was also included in the models.
Socio-demographic Characteristics of Study Population
Variables
Higher SES
Current Smoking
Passive Smoking
Dust Exposure
Non-LPG fuel use
Inadequate lighting
Inadequate ventilation
Dampness in house
Mattress
Carpet
Presence of insects
Overcrowding
Mandi Gobindgarh
N=1003 (%)
Morinda
N=1001 (%)
3.0*
31.8*
36.0*
40.7*
65.5*
17.7*
26.3*
12.4*
81.1
54.5
96.3
69.7
11.8
21.0
13.2
26.7
42.1
12.0
17.8
7.2
74.3
47.6
95.3
76.5
*P<0.05
Air Pollution Levels
Ambient Air
Pollutants
SPM (g/m3)
NOx (g/m3)
SOx (g/m3)
O3 (ppm)
CO (g/m3)
Mandi
Gobindgarh
N
Mean
115
890.3*
115
27.4*
115
29.6*
83
0.05*
115
962.9*
*P<0.05
Morinda
N
110
110
110
82
107
Mean
291.3
7.4
8.9
0.03
113.9
Prevalence of Respiratory Symptoms
Morinda
Mandi Gobindgarh
MALES
30
25.6
FEMALES
25
32.3
35
25.2
30
21.9
24.9
25
20
14.4
15
15
12.6
10.9
10
6.4
5
20
14.5
15
9.9
10
13.6
10.6
10
5.2
5
0
*P<0.05
zi
ng
*
*
W
he
e
po
ne
a
D
ys
Ph
le
gm
gh
*
C
ou
zin
g*
he
e
*
W
po
ne
a
*
Dy
s
m
Ph
leg
Co
u
gh
*
0
Prevalence of Respiratory Diseases
Morinda
Mandi Gobindgarh
MALE
17.9
10.6
8
6
6.6
5.1
5.1
4
2.9
2
2
2
2
0.8
1.4
0.1
ch
iti
s*
A
st
hm
Tu
a
be
rc
ul
os
is
*P<0.05
C
h.
Br
on
os
is
be
rc
ul
Tu
A
st
h
m
a*
0
on
ch
i
Br
C
h.
12
10
ts
*
20
18
16
14
12
10
8
6
4
2
0
FEMALE
Prevalence of Spirometric Abnormalities
Spirometric
Abnormalities
Male
Female
Mandi
Gobindgarh
N=502 (%)
Morinda
N=501
(%)
Mandi
Gobindgarh
N=501 (%)
Morinda
N=500
(%)
Obstruction
29.9*
15.6
25.2*
12.4
Restriction
28.9
23.8
14.7
12.8
*P<0.05
Prevalence of Cough
Variables
Age (years)
< 45
 45
Smoking
Ever
Never
Fuel use
Non-LPG
LPG
Residence duration (years)
> 10
 10
Dust Exposure
Mild
Moderate to Severe
Factory worker
Yes
No
Migrant
Yes
No
Mandi Gobindgarh
(%)
Morinda
(%)
15.4*
26.8*
8.6
17.0
27.8*
16.1*
22.2
9.1
21.9*
16.5*
14.0
10.9
19.5*
20.3*
10.4
12.9
18.5*
22.4*
11.2
15.0
20.0*
20.0*
12.2
22.7*
17.3*
12.8
12.0
Prevalence of Spirometric Obstruction
Variables
Age (years)
< 45
 45
Smoking
Ever
Never
Fuel use
Non-LPG
LPG
Residence duration (years)
> 10
10
Dust Exposure
Mild
Moderate to Severe
Factory worker
Yes
No
Migrant
Yes
No
Mandi Gobindgarh (%)
Morinda (%)
24.1*
33.1*
12.1
16.5
32.9*
24.7*
26.4
10.1
28.5*
25.3*
19.7
9.9
27.0*
24.9*
14.9
13.2
27.8*
27.2*
12.2
19.0
26.5*
7.4*
13.9
-
31.2*
23.4*
12.3
14.4
*P<0.05
Association of Ambient Air Quality with Cough
(Logistic regression analysis)
Variable
Poor ambient air quality town
Age (years)
Sex (male)
Higher SES
Current smoking
Passive smoking
Non-LPG fuel use
Inadequate lighting
Inadequate ventilation
Dampness
Residence duration
Dust Exposure
Factory worker
Migrant
Overcrowding
Odds
Ratio
1.59
1.02
1.37
0.99
1.63
1.09
1.45
1.34
0.97
1.07
1.01
1.30
2.13
1.05
1.01
95% C.I.
Lower
Upper
1.21
1.02
1.02
0.96
1.18
0.81
1.08
0.84
0.64
0.71
0.99
0.97
1.41
0.79
0.76
2.12
1.03
1.85
1.04
2.26
1.47
1.96
2.14
1.45
1.62
1.01
1.75
7.1
1.40
1.33
P-Value
0.001
<0.001
0.04
0.9
0.003
0.6
0.01
0.2
0.9
0.8
0.2
0.1
<0.001
0.7
0.9
Association of Ambient Air Quality with Obstructive Defects
Variable
Poor ambient air quality town
Age (years)
Sex (male)
Higher SES
Current smoking
Passive smoking
Non-LPG fuel use
Inadequate lighting
Inadequate ventilation
Dampness
Residence duration
Dust Exposure
Factory worker
Migrant
Overcrowding
Odds
Ratio
1.86
1.01
0.86
0.99
1.61
1.11
1.81
0.84
1.16
0.98
1.00
1.05
1.19
1.11
0.87
95% C.I.
P-Value
Lower
Upper
1.43
1.00
0.64
0.96
1.17
0.85
1.38
0.55
0.79
0.67
0.99
0.81
0.79
0.85
0.67
2.42
1.01
1.14
1.04
2.21
1.46
2.38
1.27
1.69
1.43
1.01
1.37
1.81
1.45
1.13
<0.001
0.001
0.3
0.9
0.003
0.4
<0.001
0.4
0.4
0.9
0.6
0.7
0.4
0.4
0.3
Association of Residence in Poor Air Quality
with Chronic Respiratory Morbidities
Variables
Cough
Phlegm
Dysponea
Wheeze
C. Bronchitis
Asthma
Obstruction
Restriction
Tuberculosis
Odds
Ratio
1.59
1.56
1.41
1.50
3.13
2.23
1.86
1.27
1.37
95% C.I.
P-Value
Lower
Upper
1.21
1.17
1.09
1.04
2.11
1.10
1.43
0.98
0.57
2.21
2.07
1.78
2.17
4.64
4.53
2.42
1.66
3.29
0.001
0.003
0.07
0.03
<0.001
0.03
<0.001
0.08
0.5
Summary
 High level of SPM in study town.
 Chronic respiratory morbidity was higher in the
study town.
 Smoking, Non-LPG fuel users, Inadequate lighting,
Inadequate Ventilation, Dampness and Occupational
dust exposure was higher but SES was lower in
study town.
 Stratified analysis shows increased respiratory
morbidity in poor air quality town in most of the
categories of confounders.
 Logistic regression analysis reveled that high SPM
level is responsible for higher respiratory morbidity
even after controlling the effect of age, sex, SES,
Smoking, Non-LPG fuel, Inadequate lighting and
ventilation, Dampness, Occupational dust exposure.
Study Strength
 Household survey was done by choosing respondent
from community by cluster sampling, thus selection bias
was avoided.
 Information bias was avoided by conducting interview
and spirometry using same instrument and same
investigator.
 High response rate (>90%) avoided non-participant bias.
 The data collection was concurrent in both the town and
continued for two years. Thus, including any seasonal
variations.
 Not only inquiry on symptoms was conducting but
spirometry was also done according to standard
procedure given by A.T.S. and instrument was calibrated
monthly.
Study Limitation
Assessment of air pollution and
respiratory health was done at the
same time in the study.
The
occurrence
of
chronic
respiratory
disease
require
exposure to poor air quality for long
period of time.
Annual Averages of SPM in Mandi Gobindgarh
440
420
400
380
360
340
320
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

The data collected by the pollution control board shows
that the quality of the ambient air in the study town was
poor for a numbers of years and most of the migrant
workers had resided in the town for considerable
period of time.
Conclusion
It is concluded that people of Mandi
Gobindgarh, which had quite high SPM level,
have significantly more symptoms of cough,
phlegm, dysponea, wheeze, chronic bronchitis,
asthma and have obstructive defects as
compared to Morinda which had all air
pollutants below permissible level.
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