A study on spirometry in petrol pump workers of Ahmedabad, India

Transcription

1 Original Article A study on spirometry in petrol pump workers of Ahmedabad, India Ravi B. Solanki, Anjali R. Bhise, Bharat M. Dangi Department of Physiotherapy, Government Spine Institute and Physiotherapy College, Civil Hospital Campus, Ahmedabad, Gujarat, India ABSTRACT Background: Lung reactions to exposure to dust, gases, and fumes at work places have been studied in different populations. The emission level of pollutants that emit particulate matter less than 10 micrometers in size (PM 10) has been found very high in Ahmedabad. Hence, petrol pump workers in Ahmedabad are likely to get exposed to a high level of air pollution along with petrol and diesel vapors. Both of these factors can affect the respiratory health of petrol pump workers. Materials and Methods: A cross sectional observational study was conducted at 53 different petrol pumps of Ahmedabad. A total of 227 petrol pump workers underwent pulmonary function testing. Their spirometry parameters were compared with 227 age matched, healthy controls. Results: A significant reduction (P < 0.001) was found in the spirometry parameters, such as, forced vital capacity (FVC), forced expiratory volume in the first second ( ), forced expiratory flow ( ), and peak expiratory flow rate (PEFR) in petrol pump workers, as compared to the controls. The mean values of /FVC (%) were significantly increased (P < 0.001). A decline in FVC was not significantly different among the workers according to the duration of exposure. As the duration of exposure increased, there was a progressive decline in /FVC (%) and. Conclusion: The study concludes that the deleterious effects of air pollution and petrol/diesel vapor inhalation on the lung function of petrol pump workers results in a restrictive type of lung function abnormality. The pattern of respiratory impairment changes to a mixed type as the duration of exposure increases. KEY WORDS: Occupational exposure, petrol/diesel vapors, petrol pump workers, restrictive impairment, spirometry Address for correspondence: Dr. Ravi B Solanki, Department of Physiotherapy, Government Spine Institute and Physiotherapy College, Civil Hospital Campus, Asarwa, Ahmedabad , Gujarat, India. E mail: ravibsolanki@gmail.com INTRODUCTION Rapid industrial growth, globalization, and poor environmental conditions at work places have created a lot of health related issues. There is a high prevalence of occupational diseases, such as, silicosis, asbestosis, and pneumoconiosis among workers working in different industrial environments in India. [1] Fast urbanization trends have resulted in a tremendous rise in the number of transportation vehicles, thereby, resulting in the increased need of petrol. This increase in demand of petrol has led to a steady rise in the number of petrol pumps in the country. On account of the lack of Quick Response Code: Access this article online Website: DOI: / availability of sufficient international research on the occupational aspects of petrol pump workers, the present study focuses on the occupational health related issues in this population. The rising number of vehicles has sharply increased the level of air pollution in various cities of India. A Health Survey done by the Centre for Science and Environment (CSE), New Delhi, has shown that 141 (80%) cities in India exceed the PM 10 (pollutants that emit particulate matter of less than 10 micrometers in size) standard, 90 cities have a critical level of PM 10 and 26 cities have the most critical level, exceeding thrice the standards. [2] In a study involving six cities of India, the measured annual PM10 concentration in microgram per cubic meter (µg/m 3 ) averaged 94.0 ± 20.4 in Ahmedabad, exceeding the annual standard of 60 µg/m 3, along with other five cities. [3] It has been found that an increase of 10 μg/m 3 of PM10 and NO 2 is associated with a decrease of about 3% and 0.7% in (forced expiratory volume in the first second), respectively. [4] The emission of pollutants from motor vehicles can be evaporative Lung India Vol 32 Issue 4 Jul - Aug

2 emission, exhaust emission or crankcase (running loss) emission, out of which 20 32% is due to evaporative emissions. [5] Owing to the volatile nature of petrol and the high environmental temperature in a city like Ahmedabad, hydrocarbon vapors from the petrol evaporate constantly into atmosphere, mainly from fuel lines, fuel tanks, and carburetors, depending upon the fuel composition, engine operating temperature, and ambient temperature. Hence, in addition to exhaust emission, petrol pump workers are also exposed to evaporative emission of pollutants. A detailed study conducted in Italy to determine the exposure of petrol pump workers to the benzene content of petrol has shown the highest benzene concentrations in the breathing zone of petrol station attendants. [6] The study also shows that in a single refueling operation that lasts for about one minute, the mean air concentration of benzene to which a petrol pump worker is exposed is 3709 μg/m 3. In addition, most of the benzene (88%) is emitted while supplying fuel to the vehicle. [6] The toxic effects of the benzene content of petrol on the various hematological indices and liver have been studied in gasoline filling workers, [7,8] with documented neurotoxicity. [9] Petrol pump workers work 10 hours/day and six days/week at most of the pumps. The high level of environmental pollution and exposure to petrol and diesel vapors can have an impact on the lung function of petrol pump workers. Chest radiographs and arterial blood gas (ABG) analysis are unable to detect any significant airway obstruction in the early stages of respiratory disease. Spirometry is a valuable tool to assess lung function in the initial asymptomatic stages of respiratory dysfunction, as compared to other tools. It has been documented that only spirometry enables the detection of chronic obstructive pulmonary disease (COPD) five to ten years before shortness of breath develops. [10] Petrol pump workers, who are asymptomatic, may have abnormal lung function. Hence, the purpose of this study is to assess the lung function of petrol pump workers by means of spirometry. MATERIALS AND METHODS A total of 53 (out of 107) petrol pumps were randomly selected from five different zones of Ahmedabad city. From these 53 petrol pumps, a total of 227(out of 358) non smoking petrol pump workers (working as petrol/ diesel filling workers for >1 year, at least 8 hours/day), in the age group of years, were selected as the study group. The petrol pump workers were matched with 227 non smoker office employees for age, gender, height, and weight. The subjects with presence or history of any respiratory illness, abdominal or chest surgery, neuromuscular disease or musculoskeletal abnormalities involving the upper trunk or rib cage, and those who were smokers, were excluded from the study. The Ethical Committee clearance and an informed consent of the subjects were taken. The petrol pump workers were classified into three different groups according to their duration of work [Table 1]. All subjects were first interviewed using a questionnaire that included the demographic data, smoking habits, duration of exposure, surgical history, past medical history of any respiratory illness, and use of any personal protective equipment resembling a face mask. Subjects who fulfilled the inclusion criteria were explained the purpose of the study. Spirometry was done in a sitting position using the computerized pulmonary function testing (PFT) machine (RMS MED SPIRER, Helios 401) and the guidelines of the American Thoracic Society were strictly followed. [11] The subjects were instructed about the procedure of the FVC (forced vital capacity) maneuver and were asked to perform it thrice. Proper rest was given in between each trial. The best value of the three was recorded. The lung function parameters studied were FVC (forced vital capacity), (forced expiratory volume in 1 second), /FVC, (average forced expiratory flow rate over the middle 50% of vital capacity), and PEFR (peak expiratory flow rate). The spirometry data of the study and control groups were compared using the student s t test using the computer software Microsoft Office Excel Within group analysis of data was done for the petrol pump workers using the one way analysis of variance (ANOVA) test and a Post hoc test using the GraphPad PRISM 5.01 software. RESULTS A total of 227 petrol pump workers and 227 office workers participated in this study. The demographic details of all are shown in Table 2. The mean age and duration of exposure of the petrol pump workers are shown in Table 3. There was a moderately positive correlation between the age and duration of exposure [Table 3]. No personal protective equipment, such as a face mask, was used by any of the workers in the present study. Comparison of the predicted and observed lung function parameters in petrol pump workers showed a significant reduction (P < 0.001) Table 1: Classification of petrol pump workers Group Duration of work (years) Number of workers 1 < >10 61 Table 2: Demographic details of subjects Subjects (n=227) Mean±SD Age (years) Height (cm) Weight (kg) Petrol pump workers 38.12± ± ±10.58 Control 37.79± ± ±9.68 SD: Standard deviation Table 3: Age and duration of exposure Variables (years) Mean±SD Intraclass correlation coefficient (r) Age 38.12± Duration of exposure 9.30±7.43 SD: Standard deviation 348 Lung India Vol 32 Issue 4 Jul - Aug 2015

3 in the observed mean values of FVC,,, and PEFR [Table 4]. The observed mean values of /FVC (%) were significantly increased (P < 0.001), as compared to the predicted values [Table 4]. Comparison of the predicted and observed mean values of various spirometry parameters in the controls showed a significant (P < 0.001) increase in the observed mean values of FVC,, and /FVC, as compared to the predicted values [Table 5]. Table 5 also shows that the predicted and observed mean values of and PEFR among the controls were not significantly different (P > 0.05). Table 6 and Figure 1 show the comparison of the spirometry parameters between petrol pump workers and controls. Table 6 also shows a significant reduction (P < 0.001) in the mean values of FVC,,, and PEFR along with a significant increase (P < 0.001) in the mean value of /FVC (%) in petrol pump workers, as compared to the controls [Figure 2]. Table 7 shows a comparison of the lung function parameters between controls and all three groups of petrol pump workers. Comparison of the lung function parameters among the three groups of petrol pump workers [Table 8] revealed no significant difference (P > 0.05) in the mean values of FVC,, Table 4: Spirometry parameters in petrol pump workers Parameters Mean±SD P value Significance Predicted Observed FVC (L) 3.40± ±0.59 <0.001 HS (L) 2.87± ± S /FVC % 84.08± ±9.71 <0.001 HS (L/S) 4.25± ±1.99 <0.001 HS PEFR (L/S) 8.84± ±1.72 <0.001 HS HS: Highly significant (P<0.001), S: Significant (P<0.01). SD: Standard deviation, /FVC: Forced expiratory volume in 1 second/forced vital capacity, PEFR: Peak expiratory flow rate Table 5: Spirometry parameters in controls Parameters Mean±SD P value Significance Predicted Observed FVC (L) 3.41± ±0.46 <0.001 HS (L) 2.80± ±0.36 <0.001 HS /FVC % 82.31± ±5.71 <0.001 HS (L/S) 3.96± ± NS PEFR (L/S) 8.34± ± NS HS: Highly significant (P<0.001), NS: Not significant (P>0.05). /FVC: Forced expiratory volume in 1 second/forced vital capacity, PEFR: Peak expiratory flow rate, FEF: Forced expiratory flow, SD: Standard deviation Table 6: Comparison of spirometry parameters between petrol pump workers and controls Parameters Mean±SD P value Significance Petrol pump workers Controls FVC (L) 3.02± ±0.46 <0.001 HS (L) 2.73± ±0.36 <0.001 HS /FVC % 90.40± ±5.71 <0.001 HS (L/S) 3.55± ±0.84 <0.001 HS PEFR (L/S) 7.28± ±1.1 <0.001 HS HS: Highly significant (P<0.001). /FVC: Forced expiratory volume in 1 second/forced vital capacity, PEFR: Peak expiratory flow rate, FEF: Forced expiratory flow, SD: Standard deviation and PEFR, while there was a progressive decline in /FVC(%) and, as the duration of exposure increased. The mean values of /FVC (%) and were significantly decreased (P < 0.05) in group 3 as compared to group 1 and group 2 [Table 9]. DISCUSSION The purpose of the present study was to assess impact of petrol/diesel vapors and environmental pollution on the lung function of petrol pump workers. The results showed a significant reduction in the spirometry parameters such as FVC,, and in petrol pump workers, as compared to their predicted values and observed values in the control group. The mean value of /FVC (%) was significantly increased in the study group as compared to the control group. Such findings suggest the restrictive nature of lung function abnormality in petrol pump workers. [12] Results in the control group showed that the predicted and observed mean values of PEFR and were quite similar (not significantly different), while the observed mean values of and FVC were significantly higher than the predicted (better than expected) values, in contrast to the study group. These findings indicate better lung function in the control group as compared to petrol pump workers, as the control group was not exposed to petrol/diesel vapors and high environmental pollution for a prolonged period of time. Similar findings have been observed in previous studies. [13,14] Studies involving short term exposure to diesel exhaust in healthy subjects have found a marked systemic and pulmonary inflammatory response, with insignificant change in lung function parameters. [15] As petrol pump workers in the present study were exposed to petrol and diesel vapors for a longer period of time (10 hours/day, >1 year), they were likely to develop chronic respiratory impairment as indicated by the results of the present study. Comparison of lung function parameters among the petrol pump workers according to the duration of exposure Petrol pump workers Controls FVC(L) (L) FEF (L/S) PEFR(L/S) Figure 1: Comparison of the observed mean values of FVC,, FEF25 75, and PEFR, between petrol pump workers and controls Lung India Vol 32 Issue 4 Jul - Aug

4 revealed that the mean values of FVC and were not significantly different between all three groups, but there was a significant decline in the mean values of /FVC (%) and in group 3 (>10 years) as compared to group 1(<5 years), and group 2 (5 10 years). This type of picture indicates that the restrictive pattern of Petrol Pump Workers /FVC (%) Controls Figure 2: Comparison of the observed mean values of /FVC (%), between the petrol pump workers and controls Table 7: Spirometry parameters of petrol pump workers according to duration of exposure Parameters Mean±SD Controls (n=227) Group 1 (<5 years) (n=56) Group 2 (5-10 years) (n=110) Group 3 (>10 years) (n=61) FVC (L) 3.61± ±0.48* 3.08±0.59* 2.94±0.56* (L) 3.12± ±0.47* 2.81±0.51* 2.58±0.48* /FVC % 84.86± ±6.76* 91.27±7.59* 88.25±7.22* (L/S) 4.0± ± ± ±0.92* PEFR (L/S) 8.22± ±1.53* 7.53±1.63* 7.11±1.70* *Highly significant when compared to controls (P<0.001). Significant when compared to controls (P<0.05). SD: Standard deviation, /FVC: Forced expiratory volume in 1 second/forced vital capacity, PEFR: Peak expiratory flow rate, FEF: Forced expiratory flow Table 8: Comparison of spirometry parameters among petrol pump workers according to duration of exposure (One way ANOVA for comparison between groups) Parameters F P value Significance FVC (L) NS (L) NS /FVC (%) S (L/S) S PEFR (L/S) NS NS: Not significant (P>0.05), S: Significant (P<0.01), ANOVA: Analysis of variance, /FVC: Forced expiratory volume in 1 second/forced vital capacity, PEFR: Peak expiratory flow rate, FEF: Forced expiratory flow lung function abnormality was changed to a mixed pattern of respiratory impairment, as the duration of exposure increased to >10 years. These findings support the results of the previous studies. [16,17] Petrol is a complex combination of hydrocarbons, which on emission generates particles with a diameter of 0.02 nm. These particles, due to their large surface area, can carry various toxic compounds that are likely to remain in atmospheric air for a longer period and can deposit them in the small airways on inhalation. [17] Long term exposure to such particles can cause chronic respiratory impairment, which includes lung parenchyma and small airways. The ambient air concentration of carbon monoxide (CO) has been found to be maximum in areas surrounding petrol stations during peak hours (6 a.m. 2 p.m.), as compared to residential areas, in a study done by Nazia Uzma et al. [16] Thus, a high level of environmental pollution in cities like Ahmedabad and in areas surrounding petrol pumps can have an additional deleterious impact on the respiratory health of petrol pump workers. In the present study, all smoking petrol pump workers were excluded. It has been found that an urban smoker, who works adjacent to a busy road for eight hours per day is exposed to a daily benzene dose of 819 µg/day, while that of an urban non smoker is 95 µg/ day. [6] Hence, smoking petrol pump workers are at an even higher risk of developing lung function abnormalities, as compared to non smoking petrol pump workers. In addition, the risk of lung function abnormalities in petrol pump workers also increases due to the neglect of using personal protective equipment, such as a face mask, by each worker, in the present study. Change from restrictive to mixed variety of impairment Studies involving distribution of particulate matter in human lung have shown a major site of impact and injury at the level of the terminal bronchioles and adjacent first generation respiratory bronchioles. [18] There was relative absence of the retained particulate matter in large conducting airways reflecting more rapid clearance of particles from these regions. [19] This may be the reason for a restrictive impairment in all three groups of petrol pump workers in the present study. Aging can be a contributing factor in the change from a restrictive to a mixed variety of impairment. Studies have shown that the estimated rate of decline in is ml/year starting at the age of years and can Table 9: Tukey s multiple comparison test Parameter Group 1 vs. Group 2 Group 1 vs. Group 3 Group 2 vs. Group 3 P value 95% CI of diff P value 95% CI of diff P value 95% CI of diff FVC (L) to to to (L) to to to /FVC (%) to * to to (L/S) to to * to PEFR (L/S) to to to Significant (P<0.01),*Highly significant (P<0.001), /FVC: Forced expiratory volume in 1 second/forced vital capacity, PEFR: Peak expiratory flow rate, FEF: Forced expiratory flow, CI: Confidence interval 350 Lung India Vol 32 Issue 4 Jul - Aug 2015

5 double to 60 ml/year after the age of 70 years. [19] Aging also causes a decrease in the small airway diameter. In the present study, the results show that as the duration of exposure (which is positively correlated with age) increases, there is a progressive decline in (a valuable measure for small airway obstruction) and /FVC, pointing toward obstructive pathology and resulting in a mixed type of respiratory impairment. Such findings support a previous study done by Priyadarshini et al. [20] Unlike in India, exposure of petrol pump workers to petrol/diesel vapors has been restricted in USA and United Kingdom by placing a rubber hood over the delivery pump and the use of self service stations. [21] Installation of a petrol vapor recovery system has controlled occupational exposure to volatile organic compounds in many countries. The Department of Environment, Climate Change and Water, Government of New South Wales (a state of the commonwealth of Australia) has published standards and practice guidelines for vapor recovery at petrol pumps. [22] The stage I (vapor recovery) system limits the emissions of volatile organic compounds that result from unloading petrol from a road tanker into petrol pump storage tanks. The stage II (vapor recovery) system is designed to capture the vapor displaced when vehicles are refueled at petrol pumps. Countries like USA have had stage I (vapor recovery) system for many years and have now graduated to stage II. A study done by Agip Petroli (an Italian oil company) has estimated that introduction of the petrol vapor recovery system will be capable of reducing benzene emission by 80% during the fuel in flow and by 50% during removal and replacement of the nozzle and closure of the vehicle tank. [6] Although some of the states like Delhi, in India, have a few petrol pumps with the vapor recovery system, its installation is not mandatory in any of the states of India. In India, there is no standardization regarding the number of petrol pumps in a particular geographical area, the number of workers employed in a particular petrol pump; their duration of work or the use of personal protective measures. In addition, most of the petrol pump workers belong to the lower socioeconomic class. All these aspects need to be given due consideration for the occupational hygiene of petrol pump workers CONCLUSION We found lung function abnormalities in petrol pump workers. The pattern of respiratory impairment is restrictive, which changes to a mixed variety as the duration of exposure to petrol and diesel vapor increases to >10 years. Future studies are required to investigate the effects on the diffusion capacity of the lungs and other pulmonary markers in petrol pump workers. ACKNOWLEDGMENT The authors would like to thank Dr. (Prof.) M. M. Prabhakar, Director, Government Spine Institute and Physiotherapy College, for providing all the necessary support and facilities. They thank Mr. Pritesh Patel for his contribution toward the process of data collection. The authors are grateful to Dr. M. K. Lala and Dr. Dinesh Rathod, Professors, Department of Community Medicine, B.J. Medical College, Ahmedabad, for their contribution to the statistical analysis, and they are indebted to Mrs. Yagna Shukla, Senior Lecturer, Government Physiotherapy College, Ahmedabad, and to Mr. Dhruv Dave and Dr. Viraj Bhise for their contribution toward manuscript editing. REFERENCES 1. Saiyed HN, Tiwari RR. Occupational health research in India. Ind Health 2004;42: Air Pollution is now the fifth largest killer in India says newly released Findings of global Burden of Disease report. Available from: cseindia.org/node/4831. [Last accessed on 2013 Jul 09]. 3. Guttikunda SK, Jawahar P. Application of SIM air modeling tools to assess air quality in Indian cities. Atmos Environ 2012;62: Sunyer J. Lung function effects of chronic exposure to air pollution. Thorax 2009;64: Bhandarkar S. Vehicular pollution, their effect on human heatlh and mitigation measures. VE 2013;1: Duarte Davidson R, Courage C, Rushton L, Levy L. Benzene in the environment: An assessment of the potential risks to the health of the population. Occup Environ Med 2001;58: Mahmood NM. Relationship between exposure to petrol products and the trace metal status, liver toxicity and hematological markers in gasoline filling workers in Sulaimani city.j Environ OccupSci 2012;1: Okoro AM, Ani EJ, Ibu JO, Akpogomeh BA. Effect of petroleum products inhalation on some haematological indices of fuel attendants in CalabarMetropolis, Nigeria. Niger J PhysiolSci 2006;21: Ritchie GD, Still KR, Alexander WK, Nordholm AF, Wilson CL, Rossi J 3 rd. et al. A review of the neurotoxicity risk of selected hydrocarbon fuels. J Toxicol Environ Health B Crit Rev 2001;4: Hyatt A, Scanlon P, Nakamura M. Introduction.Interpretation of Pulmonary Function Tests A Practical Guide. 3 rd ed. New Delhi: Wolters Kluwer; p Miller MR, Hankinson J, Brusasco V, Burgos F, Casaburi R, Coates A, et al.; ATS/ERS Task Force. Standardisation of spirometry.eurrespir J 2005;26: Innes JA, Reid PT. Respiratory Disease. Davidson s Principles and Practice of Medicine. 20 th ed. Churchill Livingstone: Elsevier Publishers; p Singhal M, Khaliq F, Singhal S, Tandon OP. Pulmonary function in petrol pump workers: A preliminary study. Indian J PhysiolPharmacol 2007;51: Hulke SM, Patil PM, Thakare AE, Vaidya YP. Lung function test in Petrol Pump workers. National J PhysiolPharmaPharmacol2012;2: Salvi S, Blomberg A, Rudell B, Kelly F, Sandström T, Holgate ST, et al. Acute inflammatory responses in the airways and peripheral blood after short term exposure to diesel exhaust in healthy human volunteers. Am J RespirCrit Care Med1999;159: Uzma N, Salar BM, Kumar BS, Aziz N, David MA, Reddy VD, et al. Impact of organic solvents and environmental pollutants on the physiological function in petrol filling workers. Int J Environ Res Public Health 2008;5: Madhuri BA, Chandrashekar M. A study on pulmonary function test in petrol pump workers in kanchepuram population. Int J Biol Med Res 2012;3: Pinkerton KE, Green FH, Saiki C, Vallyathan V, Plopper CG, Gopal V, et al. Distribution of particulate matter and tissue remodeling in the human lung.environ Health Perspect 2000;108: Sharma G, Goodwin J. Effect of ageing on respiratory system physiology Lung India Vol 32 Issue 4 Jul - Aug

6 and immunology. ClinInterv Aging 2006;1: Priyadarshini G, Mishra A, Mohanty RR. Effect of advancing age on pulmonary functions in petrol pump workers of Cuttack: A cross sectional study. Medical Science 2014;2: Udonwa NE, Uko EK, Ikpeme BM, Ibanga IA, Okon BO. Exposure of petrol station attendants and auto mechanics to premium motor sprit fumes in Calabar, Nigeria. J Environ Public Health 2009;2009: Standards and best practice guidelines for vapor recovery at petrol service stations. State of NSW and the Department of Environment, Climate Change and Water NSW Available from: epa.nsw.gov.au/resources/air/vaporecov09758.pdf. [Last accessed on 2014 Nov 16]. How to cite this article: Solanki RB, Bhise AR, Dangi BM. A study on spirometry in petrol pump workers of Ahmedabad, India. Lung India 2015;32: Source of Support: Nil, Conflict of Interest: None declared. New features on the journal s website Optimized content for mobile and hand-held devices HTML pages have been optimized of mobile and other hand-held devices (such as ipad, Kindle, ipod) for faster browsing speed. Click on [Mobile Full text] from Table of Contents page. This is simple HTML version for faster download on mobiles (if viewed on desktop, it will be automatically redirected to full HTML version) E-Pub for hand-held devices EPUB is an open e-book standard recommended by The International Digital Publishing Forum which is designed for reflowable content i.e. the text display can be optimized for a particular display device. Click on [EPub] from Table of Contents page. There are various e-pub readers such as for Windows: Digital Editions, OS X: Calibre/Bookworm, iphone/ipod Touch/iPad: Stanza, and Linux: Calibre/Bookworm. E-Book for desktop One can also see the entire issue as printed here in a flip book version on desktops. Links are available from Current Issue as well as Archives pages. Click on View as ebook 352 Lung India Vol 32 Issue 4 Jul - Aug 2015