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.

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

Ambient Air Quality in Major Cities During 2002

Effect of London Smog

Acute Effects of Air PollutionAuthors 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 PollutionAuthors 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.

AimThe 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

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.

Mandi Gobindgarh

Morinda

Sampling Sites

Mandi Gobindgarh

Guru ki Nagri

Prem Nagar

Morinda

Rest House Colony

Purana Bazar

Map of Mandi Gobindgarh

C HANDIG ARH

Site No . 1 - Re st Ho use C o lo ny

PURANA BAZAR

C HO C K BAZAR

LUD HIANA

REST HO USE C O LO NY

Site 2 - P urana Bazar

Map of Morinda

Sampling Site

Guru ki Nagri

Prem Nagar

Cluster Sampling

Random selection of household and then next nearest household till 500 individuals enrolled from each of study site.

Sample DesignAge Groups

(years)Male Female

20-29 100 100

30-39 100 100

40-49 100 100

50-69 100 100

70+ 100 100

Total 500 500

Study ToolsQuestionnaire Respiratory symptoms and diseases, SES (Kuppuswami scale), Household environment, Smoking history, Occupational historyPhysical Examination Height (cm.) Weight (kg.) Spirometery by portable ventilometer

FVC, FEV1, PEFR, FEV1/FVC%

Exposure MonitoringAir 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 CollectionEligible 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

2.4

0.4

-

0.2

95.8

2.0

-

-

-

95.6

1.2

-

0.3

-

96.1

2.6

-

-

-

Spirometery

Non-Respondents

Old age

Refused

Mentally retarded

Paralysis

Inability to stand

90.8

1.4

3.2

-

0.6

-

90.4

0.2

4.6

-

0.6

91.6

1.0

1.8

0.4

-

0.4

94.3

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

Categorize Using FVC

Mild FVC >60%Moderate FVC 40-60%Severe FVC <40%

Categorize Using FEV1

Mild FEV1 >60%Moderate FEV1 40-60%Severe FEV1 <40%

FEV1/FVC LLN for FEV1/FVC FEV1/FVC < LLN for FEV1/FVC

FVC LLN for FVC FVC <LLN for FVC

NORMAL STUDY RESTRICTIVE DEFECT OBSTRUCTIVE DEFECT

Comparison of FEV1/FVC to its LLN

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 Mandi Gobindgarh

N=1003 (%)

Morinda

N=1001 (%)

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

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

Mandi Gobindgarh

Morinda

N Mean N Mean

SPM (g/m3)

NOx (g/m3)

SOx (g/m3)

O3 (ppm)

CO (g/m3)

115

115

115

83

115

890.3*

27.4*

29.6*

0.05*

962.9*

110

110

110

82

107

291.3

7.4

8.9

0.03

113.9

*P<0.05

Prevalence of Respiratory Symptoms

MALES FEMALES25.6 25.2

21.9

10.914.4

12.615

6.4

0

5

10

15

20

25

30

14.5 13.6

32.3

109.9 10.6

24.9

5.2

0

5

10

15

20

25

30

35

Cough

*

Phlegm

Dyspon

ea*

Whee

zing*

Morinda Mandi Gobindgarh

*P<0.05

Prevalence of Respiratory Diseases

17.9

5.12.9

6.6

2 2

02468

101214161820

10.6

2 1.4

5.1

0.80.1

0

2

4

6

8

10

12

Ch. Bro

nchiti

s*

Asthm

a

Tubercu

losis

Morinda Mandi Gobindgarh

MALE FEMALE

*P<0.05

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 CoughVariables Mandi Gobindgarh

(%)Morinda

(%)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

15.4*

26.8*

27.8*

16.1*

21.9*

16.5*

19.5*

20.3*

18.5*

22.4*

20.0*

20.0*

22.7*

17.3*

8.6

17.0

22.2

9.1

14.0

10.9

10.4

12.9

11.2

15.0

-

12.2

12.8

12.0

*P<0.05

Prevalence of Spirometric ObstructionVariables Mandi Gobindgarh (%) Morinda (%)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

24.1*

33.1*

32.9*

24.7*

28.5*

25.3*

27.0*

24.9*

27.8*

27.2*

26.5*

7.4*

31.2*

23.4*

12.1

16.5

26.4

10.1

19.7

9.9

14.9

13.2

12.2

19.0

13.9

-

12.3

14.4

*P<0.05

Association of Ambient Air Quality with Cough(Logistic regression analysis)

Variable Odds Ratio

95% C.I. P-Value

Lower Upper

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

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

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

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 Odds Ratio

95% C.I. P-Value

Lower Upper

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

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

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 Odds Ratio

95% C.I. P-Value

Lower Upper

Cough

Phlegm

Dysponea

Wheeze

C. Bronchitis

Asthma

Obstruction

Restriction

Tuberculosis

1.59

1.56

1.41

1.50

3.13

2.23

1.86

1.27

1.37

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

320

340

360

380

400

420

440

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

SPM (g/m3)

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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