Original Articles
Prevalence and associated factors of respiratory symptoms and illnesses among brick kiln workers in Nepal —A cross-sectional study
2024 年 6 巻 1 号 論文ID: 2024-0003-OA
詳細
2024 年 6 巻 1 号 論文ID: 2024-0003-OA
Objective: This study aimed to measure the prevalence of respiratory symptoms/illnesses and evaluate their association with similar exposure groups among brick kiln workers in Nepal. Methods: This cross-sectional survey used a modified Nepali version of the American Thoracic Society Division of Lung Diseases (ATS-DLD) questionnaire to measure the respiratory symptoms and illnesses of 390 brick kiln workers. Logistic regression analyses were performed to assess the association between respiratory symptoms and illnesses with similar exposure groups, age, duration of work, and smoking among brick kiln workers. Results: A significant number of workers reported experiencing chronic cough (12.3%), chronic phlegm (10.8%), wheezing (9.2%), chronic bronchitis (10.8%), and asthma (3.6%). Interestingly, people with similar exposure groups, such as coal crushers, were almost four times more likely to have chronic coughs and asthma. Also, coal crushers had higher rates of chronic phlegm (odds ratio [OR] 2.89; 95% confidence interval [CI], 1.26–6.61), and chronic bronchitis (OR 2.41; 95% CI, 1.02–5.65). Firemen were also twice as likely to have wheezing and chronic bronchitis. Similarly, individuals transporting red bricks were more likely to report chronic phlegm (OR 2.78; 95% CI, 1.41–5.49). Green brick stacking/carrying was used as the reference group for similar exposure groups. Conclusion: A higher significance of respiratory issues is reported in coalmen, firemen, and red brick loaders. Technology transfer and natural gas substitution are necessary to protect workers.
The brick kiln industry is pivotal in the construction sector, providing the essential building blocks for urban and rural development across Nepal1). The exponential growth of the brick manufacturing industry in Southeast Asian countries has been particularly pronounced in Nepal, where a staggering 1,100 brick kilns now operate, with the capacity of these kilns to produce 15,000 to 50,000 bricks daily. This vibrant production cycle spans 6 months, commencing in December and culminating in June2). Since 2006, brick kilns have risen to become the third-largest economic sector in the country, underscoring their pivotal role in the nation’s economic landscape3). Concentrated primarily in districts, such as Rolpa, Rautahat, Dang, Kailali, and Sarlahi, these kilns provide around 46% of workers in different kilns of Nepal4).
The intricate process of brick manufacturing in Nepal encompasses four fundamental stages: mixing, molding, sun-drying, and ultimately, baking, but these four manufacturing processes are separated into five work zones, such as green brick molding (GBM), green brick stacking/carrying (GBS/C), red brick loading/carrying (RBC/C), coal preparation (CP) and firing; these categories are called. similar exposure groups (SEGs)5). Central to this operation is clay, serving as the primary raw material for brick production. However, the baking phase, vital for solidifying bricks, relies heavily on coal, sawdust, and wood. Strikingly, coal alone accounts for 70% of the fuel employed in brick kilns, with sawdust and wood constituting 24% and 6%, respectively2).
Yet, this surge in production comes at a grave cost to the respiratory health of the labor force. Among the perils they face, none is more ominous than the inhalation of brick dust laden with crystalline silica. Emerging from common quartz rock and minerals, the inhalable particles severely threaten respiratory function6). With prolonged exposure, crystalline silica’s carcinogenic nature can wreak havoc on lung capacity, imperiling the well-being of brick kiln workers. Compounding this health risk, a seminal study conducted by the World Bank in 1996 revealed the substantial contribution of brick kilns to airborne pollutants. While cement factories and roads shared the burden, brick kilns were a significant source of total suspended particles (TSP) in the atmosphere, comprising 14% of the total. The peril escalates when considering particulate matter less than 10 microns (PM10), as these fine particles are primed to infiltrate the respiratory system. Here, brick kilns outpaced other sources, representing an alarming 28% contribution7). In tandem with these hazardous particles, brick kilns release a cocktail of toxic chemicals, including carbon monoxide (CO), sulfur dioxide (SO2), fluoride compounds, and nitrogen oxides (NOx).
Additionally, using rubber tires as fuel introduces carcinogenic dioxins into the mix, further heightening the health risks faced by workers6,7). Respiratory illnesses, a global health concern, loom even larger in developing nations. Chronic obstructive pulmonary disease (COPD), asthma, occupational lung diseases, and pulmonary hypertension afflict millions worldwide. Asthma alone afflicts a staggering 262 million individuals, with nearly 2 million succumbing annually to the insidious effects of indoor air pollution, predominantly in low and middle-income countries8). Dust, chemicals, tobacco, and smoke emerge as primary culprits in the onset of these debilitating conditions.
Considering these pressing health concerns, occupational injuries and illnesses are of paramount public health significance. Each year, a staggering 2.3 million individuals succumb to the perils of occupational accidents or work-related diseases9). Indeed, an extensive study conducted in Egypt spotlighted the stark contrast in respiratory health between brick kiln workers and their counterparts. Chronic cough, chronic phlegm, chronic bronchitis, dyspnea, chest wheezing, and asthma were all markedly elevated among brick kiln workers, underscoring the gravity of their occupational health challenges10). Despite the glaring health risks and their staggering toll, research examining the prevalence of respiratory illnesses among brick workers remains notably scarce.
This study aimed to measure the prevalence of respiratory symptoms/illnesses and evaluate their association with SEGs among brick kiln workers in Nepal. Consequently, this study is crucial in bridging this evidence gap, offering invaluable insights that can galvanize policymakers and brick factory owners toward establishing occupational-friendly environments. Additionally, the findings of this research stand poised to catalyze the formulation of laws and policies aimed at safeguarding the well-being of brick kiln workers, while also instilling a culture of hygiene and safety within the workforce.
A study was conducted in Sarlahi District, Madhesh Province, Nepal, focusing on brick kiln workers from November 2022 to April 2023. The data were collected through structured interviews by trained health workers. The study included 390 adult workers (men and women over 18 years old) who had been employed at brick kilns in Nepal and India for over a year. These workers were full-time employees during the manufacturing period and were employed by the brick kiln owners. The study used a grouping strategy based on workers with similar job roles within a production unit, SEGs
SamplingThe needed sample size was computed utilizing the subsequent formula: n = z2pq/d2, where Z represents the standard normal deviation, equivalent to 1.96 for a 95% confidence level. The prevalence rate of 19% was derived from a preceding Nepalese study on the same subject5). Hence, P was assigned the value 0.19, while q, indicating the complementary probability to P, equated to 0.81. The degree of precision, marked by d at 5% or 0.05, was set. Consequently, the sample size (n) was determined as [(1.96)2×0.19×0.81] / (0.05)2, resulting in a value of 236. A design effect 1.5 was applied to the sample size, yielding a revised figure of 354. Similarly, considering a non-respondent rate of 10% from the sample, 390 participants were recruited in the study.
Study procedureThe initial step involved obtaining the sampling frame from the administrative office of the small cottage industry located in Sarlahi. The Sarlahi district accommodated a total of 80 brick kilns. Subsequently, certain brick kilns were visited to gather insights into the work environment and the workforce count within an individual brick kiln. The selection of workers for the sample frame was accomplished through telephone inquiries and physical visits to the brick kilns.
The study used systematic random sampling to select 10 out of 80 brick kilns. The sampling interval was calculated using the formula: K = Population size (N)/Sample Size (n). In this instance, the resulting sampling interval equated to 8. A number was chosen at random between 1 and 8, and this number turned out to be 5. As a result, the brick kilns selected for the study were numbered 5, 13, 21, 29, 37, 45, 53, 61, 69, and 77. Each brick kiln employed a workforce ranging from 150 to 200 individuals. The smallest number of workers, 150, was found in the 21st and 69th brick kilns, while the highest count, 200, was observed in these same kilns. Consequently, a total of 39 workers were chosen at random from each brick kiln to participate in the study.
Data collection tools and techniquesThe research used the Nepali version of the standard tool “American Thoracic Society Division of Lung Disease (ATS-DLD)” for data collection5). This tool is commonly used for the identification of respiratory symptoms and illnesses. It contains questions regarding the frequent chronic respiratory symptoms and illnesses including cough, phlegm, wheezing, asthma, and shortness of breath5,11,12). The study followed the Nepal Demographic Health Survey tool as a reference point to assess demographic characteristics, ensuring reliability and validity within the context of the Nepalese population. These characteristics encompassed age (in years), gender (male/female), level of education (no formal education, less than primary education, primary education, secondary education, higher secondary education, and others), and migration status (within the district, outside the district, and from India).
The research objective and methodology were communicated to the owner of the brick factories with utmost clarity and confidence. The data collection process was initiated only after receiving approval from the respective factory owners, with complete assurance in the structured interview method used for data collection. The research objectives, risks, benefits, and ethics were confidently shared with the participants before data collection, ensuring their complete understanding and agreement with the research process. Confidentiality and respect for the participants were unwaveringly maintained throughout the research process.
Respiratory questionnaireSocio-demographic characteristic data were tested using a Nepali version of the field pre-test questionnaire. Likewise, the study applied a modified Nepali version of the American Thoracic Society Division of Lung Diseases questionnaire (ATS-DLD-78A) to record the presence of respiratory symptoms and illnesses5,11,12).
Operational definitions of the study outcomes:Chronic cough: cough as much as 4–6 times per day occurring for most days of the week (≥5 days) for at least 3 months of the year and at least 2 consecutive years.
Chronic phlegm: sputum expectoration as much as twice a day for most days of the week (≥5 days) for at least 3 months of the year and at least 2 consecutive years.
Wheezing: chest ever sounds wheezy or whistling most days or nights in the past 2 months.
Dyspnea was divided into 5 grades with the following definitions a) Grade 0: No Breathlessness except with strenuous exercise b) Grade 1: Breathlessness when hurrying on the level or walking up a slight hill c) Grade 2: Walking slower than people of the same age on the level because of breathlessness or has to stop for breath when walking at own pace or level d) Grade 3: Stopping for breath after walking about 100 yards (96 meter) or a few minutes on the level e) Grade 4: Too breathless to leave the house or breathless when dressing or undressing.
Chronic bronchitis: cough and sputum expectoration occurring for most days of the week (≥5 days) for at least 3 months of the year and at least 2 consecutive years.
Asthma: at least two or more attacks of shortness of breath with wheezing (whistling sound on expiration) in the past 2 months with normal breathing in between episodes of shortness of breath or diagnosed asthmatic by a physician.
Ever smoker: more than 20 packs of cigarettes in a lifetime or more than 1 cigarette a day for 1 year.
Never smoker: less than 20 packs of cigarettes in a lifetime or less than 1 cigarette daily in 1 year.
Statistical analysisThe data was entered into Excel and analyzed using IBM SPSS 25 Univariate analysis was performed to determine the frequencies, proportions, mean, median, and range of participants’ sociodemographic characteristics. Bivariate and multivariate logistic regression analyses were conducted to evaluate the association between respiratory symptoms/illnesses (such as chronic cough, chronic phlegm, chronic bronchitis, wheezing, and asthma) and exposure to various groups, including green brick molding, green brick stacking/carrying, red brick loading/carrying, coal preparation, and fireman duties. The GBC/Ls zone workers were used as the reference group in the logistic regression analysis among SEGs due to their lower exposure to dust particles compared to the other SEGs, as green brick materials are kept wet, reducing the release of dust into the air. Additionally, duration of work, smoking, and age were included as adjusted factors in the multivariate logistic analysis, with statistical significance set at P<0.05.
Nearly half (46.6%) of the study subjects were involved in GBM, with a majority from the Sarlahi district (58.7%). Most workers were male (83.3%), and many had no formal education (65.4%). Their average age was around 38 years, with a significant portion (32.1%) in the 40-to-50-years age group. They typically worked for about 4 years and spent roughly 9.34 hours per day working. Interestingly, while the majority did not smoke, among those who did, they started around age 20 years and smoked about 5 cigarettes a day (Table 1).
| Socio-demographic variables | Number(n) | Percentage (%) |
|---|---|---|
| Work station | ||
| Green brick molding | 178 | 46.6 |
| Green brick stacking/Carrying | 52 | 13.3 |
| Red brick loading/ Carrying | 79 | 20.3 |
| Coal preparation/Coalman | 39 | 10.0 |
| Firemen | 42 | 10.8 |
| The age group of respondents | ||
| Mean (SD): 37.98 (11.83) years | ||
| 18–28 years | 87 | 22.3 |
| 29–39 years | 121 | 31.0 |
| 40–50 years | 125 | 32.1 |
| 51–61 years | 47 | 12.1 |
| ≥62 years | 10 | 2.6 |
| Gender | ||
| Male | 325 | 83.3 |
| Female | 65 | 16.7 |
| Education Status | ||
| No formal education | 255 | 65.4 |
| Less than primary school | 84 | 21.5 |
| Primary school | 40 | 10.3 |
| Secondary School | 10 | 2.6 |
| +2 | ― | |
| Others | 1 | 0.3 |
| Duration of work | ||
| Median (SD): 4 (8.18) years | ||
| ≤10 years | 303 | 77.7 |
| 11–20 years | 56 | 14.4 |
| ≥21 years | 31 | 7.9 |
| Migration Status | ||
| Within district | 229 | 58.7 |
| Outside district | 26 | 6.7 |
| From India | 135 | 34.6 |
| Hours of work per day | ||
| Mean (SD): 9.34 (2.33) hours | ||
| Smoking status | ||
| Non-smoker | 227 | 58.2 |
| Ever smoker | 163 | 41.8 |
| Current smoker | 152 | 39.0 |
| Characteristics of Smokers | ||
| Age at starting smoking, median (SD): 20 (8.44) years | ||
| Cigarettes per day, median (SD): 5 (7.82) |
SD, standard deviation.
The prevalence of respiratory issues among the participants is highlighted. A notable 38% of participants reported a regular cough, with 36.4% experiencing this cough frequency about 4 to 6 times per day for 4 or more days each week. Chronic cough, however, was reported by only 12.3% of the participants. Regarding phlegm, 25.4% experienced it, with 22.3% having phlegm about twice a day. Chronic phlegm, observed in 10.8% of participants, indicated a more persistent condition. Additionally, 15.6% encountered episodic cough and phlegm, while 10.8% faced a chronic episode resembling chronic phlegm. Chronic wheezing affected 9.2% of participants, while asthma was reported by 3.6%. 27% of the participants experienced dyspnea while walking on a slight hill, categorized as grade zero, while a substantial 24% reported facing dyspnea while walking at their own pace on a level surface, classified as grade three (Table 2).
| Respiratory Illnesses | Number (n) | Percentage (%) |
|---|---|---|
| Cough | ||
| Present | 148 | 37.9 |
| Absent | 242 | 62.1 |
| Usually cough as much as 4 to 6 times a day, 4 or more days out of the week | ||
| Present | 142 | 36.4 |
| Absent | 5 | 1.3 |
| Does not apply | 243 | 62.3 |
| Chronic cough | ||
| Present | 48 | 12.3 |
| Absent | 342 | 87.7 |
| Phlegm | ||
| Present | 99 | 25.4 |
| Absent | 291 | 74.6 |
| Usually bring up phlegm as much as twice a day, 4 or more days out of the weeks | ||
| Present | 87 | 22.3 |
| Absent | 12 | 3.1 |
| Does not apply | 291 | 74.6 |
| Chronic phlegm | ||
| Present | 42 | 10.8 |
| Absent | 348 | 89.2 |
| Episodes of cough and phlegm | ||
| Present | 61 | 15.6 |
| Absent | 38 | 9.7 |
| Does not apply | 291 | 74.6 |
| Chronic episodes of cough and phlegm | ||
| Present | 42 | 10.8 |
| Absent | 348 | 89.2 |
| Wheezing on most days or nights in the past 2 months (Chronic wheeze) | ||
| Present | 36 | 9.2 |
| Absent | 354 | 90.8 |
| Asthma | ||
| Present | 14 | 3.6 |
| Absent | 376 | 96.4 |
| Prevalence of dyspnea | ||
| Grade 0 | 104 | 26.7 |
| Grade 1 | 76 | 19.5 |
| Grade 2 | 90 | 23.1 |
| Grade 3 | 70 | 17.9 |
| Grade 4 | 41 | 10.5 |
| Total | 390 | 100 |
Respiratory symptoms and illnesses such as chronic cough, chronic phlegm, wheezing, chronic bronchitis, and asthma occur among SEGs. Respective percentages of chronic cough, chronic phlegm, wheezing, chronic bronchitis, and asthma for each SEG were 5.6%, 3.4%, 5.1%, 3.9%, and 0.6% for GBM; 7.7%, 9.6%, 5.8%, 13.5%, and 1.9% for GBC/S; 16.5%, 20.3%, 12.7%, 13.9%, and 6.3% for RBC/L; 30.8%, 23.1%, 15.4%, 20.5%, and 10.3% for CM; and 21.4%, 14.3%, 19.0%, 21.4%, and 7.1% for FM. A logistic regression analysis was applied to measure the association between SEGs and respiratory symptoms/illnesses adjusted for age, duration of work, and smoking practices of workers. CM showed a strong association with chronic cough (odds ratio [OR] 3.89; 95% confidence interval [CI], 1.81–8.34); when adjusted with other predictors, they were still five times more likely to have a chronic cough (OR 5.29; 95% CI, 1.54–18.12) than GBC/S. Similarly, CM had a higher likelihood of chronic phlegm (OR 2.89; 95% CI, 1.26–6.61), chronic bronchitis (OR 2.41; 95% CI, 1.02–5.65), and asthma (OR 3.89; 95% CI, 1.16–13.07) compared to GBC/S. Likewise, FM was more likely to have chronic bronchitis (OR 2.60; 95% CI, 1.15–5.91) and chronic wheeze (OR 2.68; 95% CI, 1.13–6.36) compared with GBC/S. RBC/L were around three times more likely to have chronic phlegm (OR 2.78; 95% CI, 1.41–5.49) than GBC/S. Duration of work and age of participants was a statistically significant predictor for chronic bronchitis (OR 0.38; 95% CI, 0.20–0.74) and asthma (OR 0.24; 95% CI, 0.67–0.88). The participants’ smoking habits showed no significant predictor for respiratory illness of workers with the adjusted predictors (Table 3).
| Symptoms/Illnesses | n (%) | OR (95% CI) | AOR (95% CI) |
|---|---|---|---|
| Similar Exposure Groups | |||
| Chronic cough | |||
| Green brick molding | 10 (5.6) | 0.27 (0.13–0.56) c | 0.73 (0.22–2.46) |
| Red brick loading/carrying | 13 (16.5) | 1.55 (0.78 –3.10) | 2.42 (0.74–7.92) |
| Firing | 9 (21.4) | 2.16 (0.96–4.85) | 3.22 (0.90 –11.39) |
| Coal crushing/carrying | 12 (30.8) | 3.89 (1.81 –8.34) c | 5.29 (1.54 –18.12) b |
| Green brick stacking/carrying | 4 (7.7) | Reference | Reference |
| Chronic phlegm | |||
| Green brick molding | 6 (3.4) | 0.17 (0.07–0.41) c | 0.35 (0.10–1.20) |
| Red brick loading/carrying | 16 (20.3) | 2.78 (1.41–5.49) b | 2.54 (0.85–7.47) |
| Firing | 6 (14.3) | 1.44 (0.57–3.66) | 1.49 (0.41–5.34) |
| Coal crushing/carrying | 9 (23.1) | 2.89 (1.26–6.61) a | 2.78 (0.84–9.18) |
| Green brick stacking/carrying | 5 (9.6) | Reference | Reference |
| Chronic bronchitis | |||
| Green brick molding | 7 (3.9) | 0.20 (0.09–0.47) c | 0.28 (0.09–0.87) |
| Red brick loading/carrying | 11 (13.9) | 1.46 (0.69–3.05) | 0.99 (0.35–2.79) |
| Firing | 9 (21.4) | 2.60 (1.15–5.91) a | 1.58 (0.52–4.75) |
| Coal crushing/carrying | 8 (20.5) | 2.41 (1.02–5.65) a | 1.77 (0.57–5.50) |
| Green brick stacking/carrying | 7 (13.5) | Reference | Reference |
| Chronic wheeze | |||
| Green brick molding | 9 (5.1) | 0.36 (0.17–0.79) a | 0.95 (0.24–3.69) |
| Red brick loading/carrying | 10 (12.7) | 1.59 (0.73–3.45) | 2.59 (0.67–10.05) |
| Firing | 8 (19.0) | 2.68 (1.13–6.36) a | 3.69 (0.90–15.10) |
| Coal crushing/carrying | 6 (15.4) | 1.94 (0.75–5.01) | 2.95 (0.68–12.79) |
| Green brick stacking/carrying | 3 (2.3) | Reference | Reference |
| Asthma | |||
| Green brick molding | 1 (0.6) | 0.086 (0.01–0.67) a | 0.32 (0.02–5.29) |
| Red brick loading/carrying | 5 (6.3) | 2.27 (0.73–6.96) | 4.15 (0.46 –37.22) |
| Firing | 3 (7.1) | 2.35 (0.63–8.81) | 3.80 (0.37–38.55) |
| Coal crushing/carrying | 4 (10.3) | 3.89 (1.16–13.07) a | 5.57 (0.59 –53.02) |
| Green brick stacking/carrying | 1 (1.9) | Reference | Reference |
AOR, adjusted odds ratio; CI, confidence interval; OR, odds ratio.
Note: Significant at 0.05a
Significant at 0.01b
Significant at 0.001c
The study was designed to measure the prevalence of respiratory symptoms/illnesses and assess their association with similar exposure groups, age, smoking, and duration of work. The most commonly experienced symptom was a chronic cough at a rate of 12.3%, and only 10.8% had chronic phlegm. In contrast, the study by Sanjel et al. reported rates of 14.3% for chronic cough and 16.6% for chronic phlegm5). Similarly,10.8% of people suffered from chronic episodes of cough and phlegm, while the Sanjel et al. study reported that 19.0% had chronic episodes of cough and phlegm5). According to the previous study, the increased prevalence of respiratory illnesses can be attributed to heightened exposure to air pollution in urban areas5). The study indicates that brick kiln workers are more prone to respiratory illnesses than grocery workers due to higher exposure to dust particles in the brick kiln industry5). The current research findings align with the results of Raza and Ali’s study, including chronic cough at 11.67%, chronic phlegm at 11.67%, chronic wheeze at 15%, and asthma at 3.33%13). The evidence is clear: a similar industrial study of heavy clay in Iran and the leather industry in Pakistan demonstrates that heightened exposure to particulate matter leads to a range of health problems14,15,16).
An important revelation from this research pertains to dyspnea. The prevalence of dyspnea differs from the findings reported by Shaikh et al. (34.4% grade 1 and 11.8% grade 2 dyspnea)11) and Gupta R (13.87% grade 0, 14.59% grade 1, and 8.38% grade 2 dyspnea)17). However, results are consistent with those of Sheta and El Laithy, where dyspnea was 21.41%10). The above-mentioned respiratory symptoms are aligned with the previous study conducted on workers who were exposed to dust from wood, clay, and coal in other occupations15,17,18,19,20).
A similar study conducted in cement factories in Tanzania indicates a significant prevalence of respiratory symptoms among workers21). The lack of periodic check-ups, personal protective equipment, and health insurance could be one of the major reasons for the increased respiratory illness among Nepalese brick kiln workers22).
Multivariate logistic regression analysis was applied to assess the association between similar exposure groups and respiratory symptoms and illnesses adjusted with a duration of work, age, and smoking status. Various literature reviews suggest that workers, such as coalmen, firemen, and brick carriers, are at risk of experiencing respiratory symptoms and illnesses. This increased risk is likely due to their direct exposure to small particles of dust generated from coal, clay, and wood5,11). CM were nearly four times more likely to experience chronic cough. Similarly, CM and RBC/L were nearly three times more likely to have chronic phlegm when compared with GBS/C. GBM had a statistical significance (P<0.001) with chronic cough and chronic phlegm when compared with GBS/C. The duration of work, smoking status, and age of participants had no association between chronic cough and chronic phlegm. Upon adjustment, the association did not exist.
Workers involved in making and carrying green bricks have a lower risk of exposure compared to those handling red bricks. This is because the green brick materials are kept wet, which reduces the release of dust into the air. However, workers involved in loading red bricks are at risk of breathing in airborne particles from smoke and dry dust, which can be harmful to their respiratory health5).
Furthermore, FM and CM were more likely to have chronic bronchitis when compared with GBS/C. RBL, smoking status, and age of participants had no association with chronic bronchitis but also with adjusted predictors. Duration of work was statistically significant (P<0.004) with chronic bronchitis. The outcome of chronic bronchitis in fire masters is similar to the prior study by Sanjel et al5).
FM was almost three times more likely to have a chronic wheeze when compared with GBS/C. GBM was also statistically significant (P<0.012) with the chronic wheeze when compared with GBS/C, after adjustment, there was no significant between chronic wheeze and GBM. Factors such as the age of participants, duration of work, and smoking were found to be insignificant concerning chronic wheezing.
CM were nearly four times more likely to develop asthma compared with GBS/C. GBM and the participants’ age were also found to be statistically significant factors for asthma. Coal is considered the most hazardous substance: due to its potential to cause chronic respiratory illnesses when coal is burned, it releases harmful pollutants such as particulate matter, sulfur dioxide, nitrogen oxides, and mercury, which can severely impact respiratory health23,24).
Limitations of the studyThe study identified a remarkably high prevalence of respiratory symptoms among brick kiln workers. However, some limitations should be addressed in future research. First, due to limited resources, time, and budget constraints, the study focused mainly on descriptive findings and could not employ diagnostic procedures to measure lung function. Second, the absence of a control group in the research was due to time constraints. Despite these limitations, the findings will be valuable for policymakers and researchers, filling important gaps in the literature. In addition, the research exclusively examined respiratory issues among direct brick kiln workers, overlooking individuals affected directly and indirectly by brick kiln dust. Lastly, the study was unable to measure the dust concentration at the brick kiln due to budget limitations.
ConclusionThe study revealed that workers in coalmen, firemen, and red brick loaders job categories experience various respiratory symptoms and illnesses. The study recommends improving the work environment and creating an eco-friendly setting through technological upgrades, replacing natural gas, providing worker training, and ensuring the use of personal protective equipment. This study will be beneficial for implementing preventive and protective measures in the brick industry sector under the supervision of the Ministry of Industry and Labor.
We would like to acknowledge the president of the Sarlahi brick kiln association for permitting us to conduct research in Sarlahi brick kilns. We are also grateful to all brick kiln owners for providing a supportive environment for data collection. Thanks, also go to all the study participants for their valuable time and response, without their support, this study would not have been conducted.
Pooja Kumari contributed to conceptualization, methodology, project administration, formal analysis, writing the original draft, and reviewing and editing. Lisasha Poudel and Laxmi Chaudhary contributed to the analysis and writing of the original draft. Dr. Bishnu Prasad Choulagai supervised the study, and reviewed, and edited the manuscript. All authors read and approved the manuscript.
Data are available on reasonable request to the corresponding author. The data are not publicly available due to privacy requirements or ethical restrictions.
Ethical approval was obtained from the Institution Review Committee, the Institute of Medicine (reference no.276(6-11) E2079/080), and the Brick kiln association of Sarlahi district. The purpose, objective, and inclusion and exclusion criteria of the study were clearly explained to the participants after written consent was obtained from the brick kiln owners and participants before conducting the interview. The confidentiality of participants was ensured.
Informed consent was obtained via the standard survey form of IRC, IoM.
The authors declare that there is no conflict of interest.
