High Prevalence of Chronic Respiratory Symptoms among Autorickshaw Drivers of Urban Puducherry, South India.

CONTEXT: Auto-rickshaw (three wheelers open cabin type of vehicle) drivers are exposed to traffic air pollution. Studies have demonstrated reduced pulmonary function among drivers. However, limited studies have determined the prevalence of chronic respiratory symptoms or chronic obstructive pulmonary disease (COPD) among drivers. AIMS: Among auto-rickshaw drivers of urban Puducherry to determine prevalence of (i) chronic respiratory symptoms by using Indian Study on Epidemiology of Asthma, Respiratory Symptoms, and Chronic Bronchitis (INSEARCH) questionnaire and (ii) COPD by measuring peak expiratory flow rate (PEFR). SETTING AND DESIGNS: Cross-sectional, descriptive study. SUBJECTS AND METHODS: Cluster random sampling was used to select 297 auto-rickshaw drivers. Subjects were interviewed using the INSEARCH questionnaire. PEFR was measured using Wright's peak flow meter. We also assessed exposure to tobacco smoke. STATISTICAL ANALYSIS USED: Prevalence and 95% confidence interval of chronic respiratory symptoms and COPD were calculated.
RESULTS: All the auto-rickshaw drivers were male, and 75% were in the age group of 31-50 years. They spend most of the time on the roadside either driving or waiting at the auto-stand. Prevalence of nonspecific respiratory symptoms among auto-rickshaw drivers was 76% (breathlessness on exertion 68%, cough at night and phlegm in the morning 22%, wheezing 18% assessed for last 12 months). Around 28% of them had PEFR <80%. The prevalence of tobacco smoking was also high (64%), and 100% had exposure to tobacco smoke at the workplace.
CONCLUSION: The nonspecific chronic symptoms were high among auto-rickshaw drivers as compared to the general population noted from a multicentric study done in India. We recommend that auto-rickshaw drivers should use personal protective equipment and would require regular screening and treatment for respiratory impairment.

INTRODUCTION

Chronic respiratory problems such as asthma, chronic obstructive pulmonary disease (COPD) are increasing. Globally, COPD has been emerging as a major cause of morbidity and mortality and is expected to become the third most leading cause of death and the fifth leading cause of loss of “Disability Adjusted Life Years” (DALYs) by 2020. The burden of COPD in developing countries is even worse.[1] Half a million people die every year due to COPD in India, which is over four times higher than that in Western developed nations.[2] Occupational exposure to airborne particulates contributes to the general burden of COPD and asthma. It is estimated that 15% of COPD is work-related.[34] Long-term exposure to traffic-related air pollution contributes to the development of COPD.[5] The suspended particulate matter, sulfur dioxide, nitric oxide present in the automobile exhausts irritates the airway tract, thereby leading to the development of obstructive and restrictive lung problems.[6]

Traffic police officers, drivers, street vendors are exposed to traffic air pollution for a long duration.[67] Studies among traffic police officers and drivers show that they have reduced pulmonary function and are vulnerable to respiratory problems/impairments.[891011] This study focuses on drivers of auto-rickshaw, a three-wheeler open cabin type of vehicle used for transporting passengers. Auto-rickshaw drivers are exposed to traffic pollution for a long duration, either while driving or while waiting on the roadside till they find the next passenger. They are also likely to have other risk factors for COPD such as smoking, indoor air pollution because of low socioeconomic status.[911] Around, 49% of auto-rickshaw drivers have respiratory complaints and reduced pulmonary function and 6% have COPD.[12]

Studies demonstrated a decrease in pulmonary function among drivers. However, limited studies have determined the prevalence of COPD among drivers. Most of these studies were done on small sample size and the outcome was based on self-reporting of previously diagnosed respiratory condition.[791112] Hence, this study aimed to determine the prevalence of chronic respiratory symptoms and COPD among the auto-rickshaw drivers in urban Puducherry.

SUBJECTS AND METHODS

Study type

This cross-sectional study was conducted among the auto-rickshaw drivers of urban areas of Puducherry District during August–September 2016.

Study setting

Puducherry district spans an area of 290 sq.km, with a population of 946,600 and population density of 3232 people per sq.km.[13] The air quality measures at Puducherry are within the standards, with the particulate matter (<10 microns) as 42 μg/m3, sulfur dioxide level as 5.1 μg/m3, and nitrogen dioxide levels as 12.2 μg/m3.[14]

Sample size and sampling

The sample size was calculated using OpenEpi software (version 3.03). The prevalence of reduced lung function among auto-rickshaw drivers was 49%;[15] a relative precision of 20% (absolute precision = 9) at 95% confidence interval (CI); a design effect of 2; and the sample size was calculated as 238. Participants were selected by cluster random sampling, and auto-stands were the clusters.

Study participants

Persons driving open cabin type of three wheeler, used for transporting passengers, for at least past 3 years in urban areas of Puducherry were included in the study. In Puducherry district, there were around 4500 auto-rickshaw drivers from 110 auto-stands. From them, 23 auto-stands were randomly selected using computer-generated random numbers. All auto-rickshaw drivers from these auto-stands who were driving auto-rickshaw for more than 3 years were included in the study. Drivers who could not be contacted in two attempts (n = 83) were excluded from the study. By following this method, we included 297 auto-rickshaw drivers.

Data collection

After obtaining the written informed consent, the auto-rickshaw drivers were interviewed by the first author using structured, validated Tamil questionnaire used in the Indian Study on Epidemiology of Asthma, Respiratory Symptoms, and Chronic Bronchitis (INSEARCH).[1617] It was a multicentric study sponsored by Indian Council of Medical Research (ICMR), conducted at four centers, namely Chandigarh, Delhi, Bengaluru, and Kanpur from 2006 to 2009. The questionnaire includes questions on respiratory symptoms such as wheezing and tightness in the chest, shortness of breath, cough phlegm, breathing, and asthma.[16] The peak expiratory flow rate (PEFR) was measured using a standard handheld calibrated Wright's peak flow meter. The procedure was done thrice, and the best of the three readings was taken.[18] All the readings were taken in standing position. Height was measured with the inch tape to the nearest 1 cm and weight measured using a bathroom scale to the nearest 0.5 kg. The readings were compared with the predicted PEFR values for the Indian men corresponding to their age.

Ethical aspects

Participants screened positive with INSEARCH questionnaire and PEFR measurement were referred to JIPMER for further evaluation. Research Monitoring Committee and Human Ethics Committee of JIPMER, Puducherry approved the study.

Statistical analysis

Data were entered in Epi-Data Manager (Version 2.0.11.61) and Epi-Data entry Client (Version 2.0.9.25). The data were analyzed using Statistical Package for the Social Sciences version 16. Proportion (95% confidence interval) of study participants having “non-specific chronic respiratory symptoms,” “asthma,” and “COPD” was calculated. Chi-square test of significance was used to compare proportions between different subgroup of participants. The P value <0.05 was considered as statistically significant.

RESULTS

We studied 297 male auto-rickshaw drivers with the mean age of 40 years [standard deviation (SD) = 8.7]. The participant's age and education are summarized in Table 1. The participants were driving auto-rickshaw for an average of 16 (SD = 8.3) years. On an average, participants were driving auto-rickshaw for 3 h/day and were waiting in the auto-stand for the next passenger for around 11 h/day. Around 64% of them had ever smoked. All of them were exposed to passive smoking, especially while waiting in the auto-stand.

Table 1

Socioeconomic details of auto.rickshaw drivers in urban Puducherry

The most common symptom was breathlessness on exertion (68%), followed by phlegm in the morning (22%), cough in the morning (21%), wheeze in the past 12 months (18%), and breathlessness on dust exposure (15%). Based on the operational definition of INSEARCH, 76% of the participants had nonspecific respiratory symptom and 2% had asthma [Table 2].

Table 2

Prevalence of respiratory symptoms, asthma, and chronic bronchitis among auto.rickshaw drivers of urban Puducherry compared with the results of INSEARCH study

Airway restriction (airway narrowing) was quantified by PEFR measured using a peak flow meter. Around 28% (95% CI: 23–34) of the participants had abnormal PEFR [Table 3]. The study did not find any association between the prevalence of chronic respiratory symptoms and subject characteristics such as age, education, tobacco smoking habit, duration of occupation as auto-driver, and total duration of driving per day.

Table 3

Peak expiratory flow rate of auto-rickshaw drivers in urban Puducherry (n=297)

DISCUSSION

This study found that three-quarter of the auto-rickshaw drivers had nonspecific respiratory symptoms based on the INSEARCH study tool. It was higher than that reported among male population in Chennai (8%), a metro-city around 150 km from Puducherry [Table 2].[17] Such high prevalence could be because of prolonged exposure to traffic exhaust pollution. Study participants were driving auto-rickshaw for an average of 16 years. Also, on an average, they spent 14 h/day on the roads and were exposed to traffic exhaust pollution. Adding to this, the prevalence of active smoking (64%) and passive smoking (100%) were high among auto-rickshaw driver. Similar observation was noted by Binawara et al.[9] In Global Adult Tobacco Survey (GATS), the prevalence of smoking among males in the general population was 24%, and exposure to second-hand smoke at the workplace was 32%.[19] Presence of nonspecific respiratory symptoms indicates an evolving COPD or some other respiratory disease such as bronchiectasis, interstitial lung disease which cannot be diagnosed using a questionnaire. Hence, further evaluation of those with nonspecific respiratory symptom is mandatory.

Around 68% of participants reported having breathlessness on exertion as compared to 4% in general population in urban Chennai.[17] Breathlessness on exertion being a nonspecific symptom could be due to respiratory problems or poor fitness. Auto-drivers are mostly sedentary, both during driving and while waiting at the auto-stand. Physical inactivity could also contribute to poor fitness.

The prevalence of asthma and chronic bronchitis was 1 and 4%, respectively, among males of the general population in urban Chennai.[17] Though the prevalence of nonspecific respiratory symptom was high, prevalence of asthma and chronic bronchitis among auto-rickshaw drivers was lesser than that observed in the general population. It could be attributed to healthy worker effect[2021] with affected drivers discontinuing their driving profession.

In the community setting, abnormal PEFR (<80%) is used to detect COPD especially those who will benefit with the use of bronchodilators.[22] In our study, one-quarter of auto-rickshaw drivers had abnormal PEFR (<80%). Ajay et al. also found that rickshaw drivers had lower PEFR as compared to the healthy adult of other occupation.[11] A study done in Bikaner, India found that three-wheeler diesel taxi drivers, especially smokers, had reduced pulmonary function test.[9] Madhuri et al. found that exposure to petrochemicals significantly lowered the PEFR.[23] Our study did not find any association with other patient characteristics because the sample size was not sufficient for stratified analysis. The high prevalence of respiratory problems necessitates the use of personal protective equipment while at work. However, the usage of personal protective equipment is minimal, as the use of the masks is uncomfortable and socially unacceptable.[24]

This study used a comprehensive, validated tool used in INSEARCH study that evaluates respiratory function along with clinical or present environmental history. An objective measure of PEFR was also used to measure pulmonary function. The prevalence of COPD among auto-rickshaw drivers may be an underestimate because of the healthy worker effect. A detail evaluation of the pulmonary function was not possible due to poor response in reporting to hospital.

CONCLUSION

The nonspecific chronic symptoms were high among auto-rickshaw drivers as compared to the general population noted from a multicentric study done in India. We recommend that auto-rickshaw drivers should use personal protective equipment and would require regular screening and treatment for respiratory impairment.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.