|Year : 2016 | Volume
| Issue : 1 | Page : 36-40
Correlation of respiratory symptoms and spirometric lung pattern among petrol pump workers Karachi, Pakistan: Cross-sectional survey
Department of Community Medicine, Jinnah Sindh Medical University, Karachi, Pakistan
|Date of Web Publication||5-Feb-2016|
Department of Community Medicine, Jinnah Sindh Medical University, Karachi
Source of Support: None, Conflict of Interest: None
Background: Exposure to petroleum products which contain solvents and air pollutants can lead to harmful effects on respiratory functioning. The aim of this study was to investigate the correlation of respiratory symptoms and spirometric lung pattern among petrol pump workers Karachi, Pakistan. Materials and Methods: Cross-sectional survey was conducted; the study group consists of 300 participants which were divided into two groups 150 petrol pump workers and 150 healthy people. Physical examination and measurement of pulmonary functions by portable electronic spirometer were performed. Results: Compare to control group, petrol pump workers were predominant respiratory symptom was breathlessness during walking (90.1%) followed by shortness of breath (89.8%), cough (80.7%). After adjustment for confounders in multivariate analysis, forced vital capacity (FVC) was significantly reduced for cough (odds ratio [OR]: 6.55; 95% confidence interval [CI]: 2.12–20.12), shortness of breath (OR: 2.67; 95% CI: 1.18–6.03), and breathlessness during walking (OR: 2.65; 95% CI: 0.96–7.28). Forced expiratory volume 1 s (FEV1) was significantly reduced for cough (OR: 3.52; 95% CI: 1.88–6.59), Shortness of breath (OR: 2.92; 95% CI: 1.31–6.48), and breathlessness during walking (OR: 3.37; 95% CI: 1.43–7.90). FEV1/FVC ratio was also significantly reduced for a cough (OR: 4.61; 95% CI: 2.39–8.90), shortness of breath (OR: 4.16; 95% CI: 1.77–9.80), and breathlessness during walking (OR: 3.54; 95% CI: 1.42–8.79). Conclusion: The result indicates that there is a significant toxic effect of solvents and air pollutants on workers working in a petrol pump. Prevention technologies are needed to answer environmentally related health questions for petrol filling workers.
Keywords: Benzene, carbon monoxide, complete blood picture, pulmonary function, thyroid hormones
|How to cite this article:|
Zafar M. Correlation of respiratory symptoms and spirometric lung pattern among petrol pump workers Karachi, Pakistan: Cross-sectional survey. Int J Health Syst Disaster Manage 2016;4:36-40
|How to cite this URL:|
Zafar M. Correlation of respiratory symptoms and spirometric lung pattern among petrol pump workers Karachi, Pakistan: Cross-sectional survey. Int J Health Syst Disaster Manage [serial online] 2016 [cited 2023 Sep 21];4:36-40. Available from: https://www.ijhsdm.org/text.asp?2016/4/1/36/175670
| Introduction|| |
Health effects of occupational exposure to gasoline and air pollution from vehicular sources are relatively unexplored among petrol filling workers. Petrol filling station is a place where workers are exposed to both petrol/diesel vapors and the vehicular exhaust. Occupational exposure to diesel/petrol vapors have been shown to affect the functioning of different systems of the body.
Petrol (gasoline) is a complex combination of hydrocarbons. About 95% of components in petrol vapor are aliphatic and acyclic compounds and <2% aromatics. The benzene content of petrol has typically been in range 1–5%, but may have risen following the removal of lead additives.
Occupational benzene exposure mainly via inhalation most frequently occurs among benzene distillers in the petrochemical industry, employees of filling stations, professional (truck) drivers, and operators of machinery powered by internal combustion engines. Benzene has several toxic effects in humans, which includes hematoxicity, immunotoxicity, neurotoxicity, and carcinogenicity. Acute poisoning can lead to death with higher exposure associated with inflammation of respiratory tract and hemorrhage in the lungs. Various occupational solvents such as benzene and atmospheric polluted air are absorbed into the human body either through the respiratory tract or via epidermal contact. It causes primary respiratory symptoms and impaired pulmonary and dermatological functions. Typical 8 h benzene exposure concentrations in distribution and retail operations average <1 ppm, although exposures can reach 2–3 ppm for shorter periods.
In a study which was conducted in India, it was demonstrated that certain physiological dysfunctioning effects were constantly observed in occupationally exposed petrol workers. The data suggested that background benzene and air pollutants accounted for substantial part of respiratory, hematological, and thyroid dysfunctioning.
Another study which was conducted in northern India concluded that an altered lung function in petrol pump workers was related to the duration of exposure.
A study conducted at Sri Lanka reported that expiratory and inspiratory flow rates, peak expiratory flow rate, peak inspiratory flow rate, forced expiratory flow 25–75% (FEF 25–75%), and forced inspiratory flow (FIF50) were decreased in the study group.
Study conducted in the USA found that high-level exposure of benzene could produce liver tumors., Another study conducted in Sweden showed that some biological effect like induction of cell turnover can play a role in the carcinogenic process in the liver of fuel station workers. A study conducted in the UK found that induction of CYP2B, a subfamily of cytochrome P450, which suggested a carcinogenic process in the liver after exposure of benzene.,
Pakistan does not have an air quality standard for benzene; petrol has very high concentration of benzene as compared to an international standard which is not environmentally favorable.
The benzene concentration in major marketing companies in Pakistan such as in PSO gasoline is 3.515–5.073 wt%, 4.930–6.640 wt%, in SHELL, and 3.890–7.540 wt% in CALTEX.
Petrol pump workers do not wear personal protective equipment during filling of petrol at the workplace. Under prevailing working conditions, benzene is absorbed in lungs by inhalation and absorbed from the skin.
There are few studies conducted on this important problem in Pakistan and similar countries, and almost no community-based study is found in Pakistan, which has investigated altered pulmonary function among petrol pump workers. This study will identify the lung function abnormalities and status of pulmonary function among petrol filling workers in Karachi. It will also provide baseline data for further research and investigation of this problem which can later be helpful for the development of regulations and policies to address this problem.
To determine the correlation of respiratory symptoms and spirometric lung pattern among petrol pump workers Karachi, Pakistan: Cross-sectional survey.
| Materials and Methods|| |
This cross-sectional study was conducted in five districts of Karachi between October and December 2014. There were 300 adults (>18 years old) men who participated in this study. 150 petrol pump workers and 150 control subjects were selected. Sample size was calculated by using WHO software for sample size estimation in health studies, sample size calculation is based on previous studies conducted at India and Nigeria,, mean and standard deviation (SD) of forced vital capacity (FVC) and forced expiratory volume 1 s (FEV1) of lung function as reported by previous studies, and considering 5% difference in the above parameters as the clinically relevant difference, the required sample size is estimated is 300 individuals were required. Registered petrol pump is a sampling frame of our study; we will draw a random sample from registered petrol pump form this list. The control group was obtained nearby residential area of the same age group of people.
Inclusion criteria for petrol pump workers: Petrol filling workers who are no history of present/previous respiratory illness, duration of exposure 8 h a day for more than 2 years. Exclusion criteria for petrol pump workers: Petrol filling workers who were not giving consent to participate in the study. Inclusion criteria for control group: Normal healthy subjects who are not exposed to petrol/diesel vapors, no history of previous/present respiratory illness. Exclusion criteria for control group: Normal healthy subjects who are refused to participate in the study. Study variables: Dependent variable: Respiratory impairment (obstructive, restrictive, mixed, and peripheral airway obstruction [PAO]) was classified on the basis of the following criteria – restriction: FVC (<80% predicted); obstruction: FEV1% (<80% predicted); FEV1/FVC% (<70% predicted). Independent variables: Sociodemographic age, height, weight, educational level, smoking habits, current medical history, past medical history, family history, drug history, and allergy history.
Occupational variable Place of work, duration of work, illness relating to occupation, protective measures, abstenism of work, operational definitionrespiratory impairment, obstructive, restrictive, mixed, and PAO were classified on the basis of following criteria. Restrictive: FVC <80% of predicted. Obstructive: FEV1% or FEV1/FVC% of (<70% predicted) predicted. Predicted values of lung functions were calculated using Rastogi's prediction equation  and per cent predicted was calculated for alteration in lung functions among workers.
Data were collected by trained data collectors. Contact with petroleum dealer association, they were provide petrol pump list who are registered with petrol pump dealer. Select petrol pump form list and received a list of petrol filling workers then. The participants were selected randomly form the list and arrange an interview at their workplace and test pulmonary function by a spirometer. The control group was selected from a nearby resident of petrol pump who are working in the office. He was assured that no information regarding the interviews will be shared to anyone, and this information will be used only for research purpose only and his identity will not be disclosed at any point in time. Questionnaires were be marked by identification number. Field testing of the final questionnaire will be done. Forms were checked for completeness daily. Data were entered twice and then cleaned for any missing variables data collection process was supervised by the principal investigator.
A structured questionnaire including all relevant questions of the objectives of the study has been developed and adapted from previous studies and opinion of various experts. The questionnaire was developed in English, translated into Urdu and pretested among petrol pump workers. Spirometer: Standard portable spirometer was used for testing the pulmonary function of study participants.
Data analysis plan
EpiData Entry software version 1.3 was used for data entry. Data were entered twice and then clean for any missing variables. Data were analyzed using software of SPSS version 16. Relationships between categorical independent and dependent variables were assessed by applying multivariate logistic regression was used to eliminate the confounders.
Before enrolling the study participants, key stakeholders operating in the study areas were informed about the nature and objectives of the research. The participant will be informed about study objective and procedures, and informed consent will take from the study participant. The interviews were conducted in a private room for reasons of privacy, no sharing of information and even name not mentioned in the questionnaire, counseling was done after the interview, no direct benefit to participant, study participant were free to withdraw from the study at any time.
| Results|| |
The frequency of sociodemographic and demographic characteristics of study participants is given in [Table 1], the mean age of petrol pump workers was 29.89 years with SD (10), and the comparison group was 28.63 years and SD (11.28). Mean height and weight of petrol pump workers and the comparison group were 170.11 cm, 67.19 kg and 171.02 cm, 69.22 kg, respectively. Most (84.4%) of petrol pump workers were educated up to primary level, and 87.2% comparison group were educated secondary level. Approximately, 66.7% of pump workers were smokers and only 33.3% were comparison group.
|Table 1: Demographic characteristics of the petrol pump worker and comparison groups|
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Frequency distribution of respiratory symptoms and lung function of study participants is given in [Table 2], most common respiratory symptoms were recoded among pump workers, and the comparison group was a cough (80.7%) and 19.3%, shortness of breadth 89.8% and 10.2% and breathlessness during walking 90.1% and 9.9%, respectively. Mean of percentage predicted lungs volumes for pump workers and comparisons group were recorded as FVC 72.6 (±7.23) and 90.32 (±9.25), FEV1 77.56 (±17.46) and 94 (±10.46), FEV1/FVC ratio 82.89 (±18.10) and 89.73 (±9.96), respectively and all values were statistically significant difference between pump workers and comparisons group.
|Table 2: Frequency distribution of respiratory symptoms and lung function among study population in Karachi, Sindh, Pakistan|
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Crude and adjusted logistic regression analysis of respiratory symptoms and spirometric lung function is given in [Table 3], symptoms with percentage predicted lung volumes entered as dichotomous variables (FVC >80% vs. <80%; FEV1 >80% vs. <80% and FEV1/FVC ratio >0.7 vs. <0.7). In the multivariate model, adjustment was done for age, height, weight, sex, smoking status, education, and socioeconomic status. After adjustment for confounders in multivariate analysis, FVC was significantly reduced for cough (odds ratio [OR]: 6.55; 95% confidence interval [CI]: 2.12–20.12), shortness of breath (OR: 2.67; 95% CI: 1.18–6.03) and breathlessness during walking (OR: 2.65; 95% CI: 0.96–7.28).
|Table 3: Crude and adjusted logistic regression analysis of respiratory symptoms with spirometric lung function|
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FEV1 was significantly reduced for a cough (OR: 3.52; 95% CI: 1.88–6.59), Shortness of breath (OR: 2.92; 95% CI: 1.31–6.48) and breathlessness during walking (OR: 3.37; 95% CI: 1.43–7.90). FEV1/FVC ratio was significantly reduced for a cough (OR: 4.61; 95% CI: 2.39–8.90), Shortness of breath (OR: 4.16; 95% CI: 1.77–9.80) and breathlessness during walking (OR: 3.54; 95% CI: 1.42–8.79).
| Discussion|| |
This is the first studies to report respiratory symptoms and spirometric values among petrol pump workers in Pakistan. The study shows that respiratory symptoms of a cough, shortness of breath, and breathlessness during walking are significantly correlated with reduced lung function and this trend was found consistently for all lung volumes (FVC, FEV1 and FEV1/FVC). This correlation suggests that the presence of respiratory symptoms is an important predictor of impaired lung function among petrol pump worker.
Several studies are shows that the work exposure of petroleum products, showing the decline in FVC, FEV1 and FEV1/FVC. The studies conducted by Zuskin et al., Lee et al. found that the exposure to solvents at workplace had significantly more respiratory symptoms than the control group. Another study conducted  showed that occupational exposure to organic solvents might cause chronic airway impairment with nonspecific bronchial hyperresponsiveness in shoe factory workers. Kesavachandran et al. found that high prevalence of respiratory symptoms was primarily a consequence of exposure to the petrol vapors found in the workplace in the petrol filling stations.
This study has reported a significant association of all symptoms with both obstructive and restrictive lung patterns. These findings are similar to those reported in other studies. A number of studies conducted on different occupational groups have shown association of selective symptoms with reduced lung function. In one study symptoms of a cough and shortness of breath were found to be significantly associated with obstructive pattern as of respiratory disease.
This study has few limitations that need to be considered. Due to cross-sectional nature of the study, it is difficult to establish a causal association between impaired lung function and the respiratory symptoms. Nevertheless, the consistent trend of decrement in lung volumes is of importance and provides basis for further research. This study was not powered to detect the risk factors associated with respiratory symptoms due to limited sample size.
| Conclusion|| |
This study demonstrated that certain physiological dysfunctioning effects are constantly observed in the occupationally exposed petrol workers. The data suggests that background benzene and air pollutants could account for substantial part of respiratory dysfunctioning. In order to prevent these among petrol filling workers, we suggest that medical observation, including pre-employment and periodic medical Checkups, should be performed which include pulmonary function tests. Control strategies should to adopt to reduce the benzene concentration in the ambient air and evaporation control. Early recognition and possibly the removal of sensitive workers from the working place before chronic impairment develops will help.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]