|Year : 2022 | Volume
| Issue : 1 | Page : 28-32
Study on occupational ventilatory defects among workers employed in cement factories of Darjeeling district, West Bengal, India
Payel Sarkar, Daliya Biswas, Eashin Gazi, Kaushik Ishore
Department of Community Medicine, North Bengal Medical College, Darjeeling, West Bengal, India
|Date of Submission||19-Jun-2021|
|Date of Acceptance||07-Jan-2022|
|Date of Web Publication||30-Jun-2022|
Department of Community Medicine, North Bengal Medical College, Darjeeling, West Bengal
Source of Support: None, Conflict of Interest: None
Introduction: Cement factory workers are at a high risk of exposure to crystalline silica-laden cement dusts and at a higher risk of developing chronic obstructive pulmonary disease (COPD), like chronic bronchitis, emphysema and restrictive lung disease like silicosis. This study was done to measure the extent of occupational ventilatory defect among workers employed inside cement factories.
Material and Methods: A cross sectional study was conducted among cement factory workers using questionnaire on respiratory symptoms 1986 and spirometry was done after seeking permission from the concerned authority and Institutional Ethics Committee. Logistic regression analysis was done to test for statistical significance.
Results: Ventilatory defect was present among one fourth of the factory workers. Obstructive type of lung disease was much higher (94.6%) than restrictive lung disease (5.4%). Almost half of the study subjects had presented with different types of respiratory symptoms. Breathlessness on exertion was commonest symptom, followed by cough day and night. Ventilatory defects were noted to be much higher (86.5%) among the workers working in the cement factories for more than 10 years and increasing trend was observed with increment in their age and years of working at the factory. Ventilatory defect were significantly high among smokers (29.5%), subjects who started smoking in early age (35.9%) and there is increasing trend of defects with a greater number of cigarettes intake.
Conclusion: Periodically awareness generation and mandatory use of personal protective equipment should be practiced among workers in cement factories.
Keywords: Cement factory, occupational, ventilatory defect
|How to cite this article:|
Sarkar P, Biswas D, Gazi E, Ishore K. Study on occupational ventilatory defects among workers employed in cement factories of Darjeeling district, West Bengal, India. Indian J Community Fam Med 2022;8:28-32
|How to cite this URL:|
Sarkar P, Biswas D, Gazi E, Ishore K. Study on occupational ventilatory defects among workers employed in cement factories of Darjeeling district, West Bengal, India. Indian J Community Fam Med [serial online] 2022 [cited 2022 Nov 27];8:28-32. Available from: https://www.ijcfm.org/text.asp?2022/8/1/28/349383
| Introduction|| |
Cement factory workers are at high risk of exposure to silica-laden cement dusts during the processes of sanding, grinding, cutting concrete, and emptying of cement bags. Cement particles are respirable and can cause occupational lung disease. Prolonged and repeated exposure to cement dust predisposes workers to various debilitating ailments such as bronchitis, emphysema, and restrictive lung disease and leads to silicosis which presents with sudden onset of fever and chest pain along with breathing difficulty, further leading to significant morbidity after few years of exposure at higher concentrations. This study was conducted to measure the extent of occupational ventilatory defect among cement factory workers and the associated factors.
| Material and Methods|| |
A cross-sectional study was conducted among purposively selected 150 cement factory workers involved in the processes of sanding, grinding, cutting of concrete, emptying of cement bags, as well as respective office staffs (50 from each) from the three cement factories of Darjeeling district from June to November 2019. Participants with documented clinical records of congenital anomalies and preexisting lung disease were excluded from the study. Information of seven participants was incomplete. The participants after fulfilling the inclusion and exclusion criteria were interviewed. Thus, the researchers could analyze the information retrieved from 143 study subjects.
After getting approval from the institutional ethics committee and from competent authorities, data were collected after obtaining informed consent, maintaining anonymity and confidentiality of the study participants by interview of the participants using Questionnaire on Respiratory Symptoms 1986. Information related to their sociodemographic and personal habits (age, years of working, whether they smoke or not, age when smoking started) was collected.
All spirometry measurements were performed by a trained pulmonology clinical technician. Spirometry test was completed using Spirolab II (Spirolab II, SDI, USA) autocalibrating device. The study participants were first introduced regarding the spirometer principal, operation, and procedure for carrying lung function testing (LFT). Before the test, individual was seated upright in a chair with arms, feet flat on floor with legs uncrossed. Tight-fitting clothing if any was loosened because tight cloth can give restrictive pictures on spirometry (give lower volumes than are true). Dentures were normally left in, unless very loose.,
A nose clip was used to minimize the loss of air through the nose during the maneuvers. All pulmonary function tests were carried out indoors, between 12:00 and 15:00 h to minimize diurnal variation. The apparatus was calibrated daily. The precise technique in executing various lung function tests for the present study was based on the operation manual of the instrument with special reference to the official statement of the British Thoracic Society of Standardization of Spirometry.
Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio, and forced expiratory flow rates at different lung volumes (including FEF25%, FEF50%, FEF75%, and FEF25-75%) were measured. At least three acceptable spirograms per subject were collected. An acceptable spirogram was defined as good start of blowing without hesitation, smooth blowing curve without artifacts, and at least 6 s of expiratory duration, or with a plateau >1 s in the end expiration in the volume–time curve.
Calculation of FEV1/FVC allows the identification of obstructive or restrictive ventilatory defects. A FEV1/FVC <70% where FEV1 is reduced more than FVC signifies an obstructive defect. An FEV1/FVC >70% where FVC is reduced more so than FEV1 is seen in restrictive defects.
Data were entered and codified in Microsoft Excel Spread Sheet. Calculation was done with the help of Excel datasheet from Microsoft Corporation and statistical software IBM SPSS version 22 made in Chicago. Relationship between ventilatory defect and its other associated factors was determined by doing multivariate logistic regression with 95% confidence interval, and P ≤ 0.05 was considered statistically significant.
| Results|| |
In the present study conducted among 143 study participants, ventilatory defect was found among 37 (25.9%) of the study participants. Obstructive type of lung disease was more (94.6%) than restrictive type of lung disease (5.4%) among these 37 subjects [Figure 1]. Almost half (49.6%) of the study subjects had presented with different types of respiratory symptoms which they had faced in the last one year before the data collection period. Twenty two percent of the subjects had history of cough day and night, 21% had cough most of the days in year and had phlegm in winter morning, 37.1% had breathlessness while hurrying, 9.1% had attacks of wheezing in the last 12 months, 4.2 had history of bronchitis, 2.8% had history of pneumonia and pulmonary tuberculosis, and 3.5% had history of bronchial asthma [Table 1]. All these symptoms were found significantly associated with ventilatory defect [Table 2]. Ventilatory defect was noted in much higher proportion among study subjects with increment in their age group, working more than 21 years in the cement factories (48.3%), habit of smoking (29.5%), and started smoking before 20 years of age and who smoked more than 21 cigarettes daily (88%). Except the age group variable, all these variables were found statistically significant association with the presence of ventilatory defect [Table 3].
|Figure 1: Distribution of the study participants according to their presence and type of ventilatory defect (n = 143)|
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|Table 1: Respiratory symptoms and lung disorders among the study participants (n=143)|
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|Table 2: Association of ventilatory defect with various types of respiratory symptoms (n=143)|
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|Table 3: Association of ventilatory defect with profile and smoking related history of the participants (n=143)|
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| Discussion|| |
A large section of the labor force in the state of West Bengal is engaged in the cement industry. Most of these labors are casual in nature and are engaged in the industry throughout the year. Due to their type of occupation, they are exposed to high level of silica-laiden particles, causing ventilatory defect among them after long time exposures. It is very difficult to motivate these daily-wage workers for participating in any type of research activities. Even though the prevalence of ventilatory defect tends to vary across studies, determinants and patterns of ventilatory defect are almost similar. The prevalence of ventilatory defect could not be compared across different studies due to their varying nature of definitions used, different questionnaires used, region selected, and methodology adopted. In the present study, the proportion of ventilatory defect was observed among 25.9% of the study participants. Obstructive type of lung disease was more than restrictive type of lung disease. A study conducted in Iran during 2009 revealed significant reductions in FEV1, FVC, and FEV1/FVC among the cement factory workers who were chronically exposed to dust.
Most prevalent symptoms in the current study was breathlessness followed by cough and phlegm.
A study in Ethiopia in 2014 revealed that the prevalence of respiratory symptoms was 66.2% in cement factories workers which was higher than the present study findings. Another study conducted in Srinagar revealed that 87%–90% workers of the three factories were found to be suffering from cough, had complaints of chest pains (50%-59%) were complained by 50%-59%, and 41%-51% had asthma. This might be due to some extent of increased use of personal protective measures, geographical differences, and general health awareness.
Ventilatory defect was noted in much higher proportion among study subjects with higher age group, more years of working, and early initiation of smoking. Similar result was noted in the study done in Ethiopia, where respiratory symptoms were higher in ≥45-year-old workers. Smoking was positively associated with respiratory symptoms in cement factories workers.
These results suggest that chronic cement dust exposure impairs lung function. Since protective gears were available, these findings suggest that either compliance to their use was poor or they were ineffective.
Selection of participants by purposive sampling could have introduced selection bias. During interview, the participants had to recall few relevant clinical histories. Hence, even after researchers' utmost efforts to exclude bias, presence of selection and recall bias might be there in the present study.
| Conclusion|| |
Proportion of ventilatory defect was much higher in this part of the country. It is recommended that the cement factory management embark on health education, acquire effective protective gadgets, and enforce their usage. Further, there should be containment of dust emission by use of dust filters.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]