Assessment of Respiratory Symptoms and Pulmonary Function Status among Workers of Flour Mills in Addis Ababa, Ethiopia: Comparative Cross-Sectional Study

Occupational exposure to dust and respiratory symptoms among Ethiopian factory workers: A systematic review and meta-analysis

BACKGROUND

Occupational respiratory disorders are a major global public health concern among workers exposed to dust particles in dust-generating workplaces. Despite fragmented research findings on the magnitude of respiratory problems and the lack of a national occupational respiratory disease recording and reporting system at the Ethiopian factory, the prevalence of respiratory symptoms among factory workers were unknown. Therefore, the aim of this meta-analysis was to summarize and pool estimates from studies that reported the prevalence of respiratory symptoms and predictors among Ethiopian factory workers who worked in dusty environments.

METHODS

A systematic literature searches were conducted using electronic databases (PubMed, Science Direct, African Journals Online, and Web of Science). The primary and secondary outcomes were prevalence of respiratory symptoms and predictors, respectively. The STATA version 17 was used to analyze the data. A random effect meta-analysis model was used. Eggers test with p-value less than 5%, as well as the funnel plot, were used to assess publication bias.

RESULTS

The searches yielded 1596 articles, 15 of which were included in the systematic review and meta-analysis. The pooled prevalence of respiratory symptoms among Ethiopian factory workers was 54.96% [95% confidence interval (CI):49.33-60.59%]. Lack of occupational health and safety (OSH) training [Odds Ratio (OR) = 2.34, 95%CI:1.56-3.52], work experience of over 5 years [OR = 3.19, 95%CI: 1.33-7.65], not using personal protective equipment (PPE) [OR = 1.76, 95%CI:1.30-2.39], and working more than eight hours per day [OR = 1.89, 95%CI:1.16-3.05] were all significant predictors of respiratory symptoms.

CONCLUSION

The prevalence of respiratory symptom was found to be high in Ethiopian factory workers. To prevent workers from being exposed to dust, regular provision and monitoring of PPE use, workers OSH training, and adequate ventilation in the workplace should be implemented.

Prevalence of obstructive lung patterns and actual spirometric result at different workplaces in Ethiopia: A systematic review and meta-analysis

Background and Aims

Burdens of occupational exposure like insoluble dust particles and chemicals in the respiratory tract leads to impaired clearance. This study aims to assess the prevalence of obstructive lung patterns and actual spirometric result in Ethiopia at different workplaces.

Methods

Five electronic databases such as: PubMed, HINARI, Science Direct, Google Scholar, and African Journals Online were searched in studies conducted from 2010 to 2021. In this study, we used STATA 14 software for data analysis and the quality of included studies were appraised using the New Castle Ottawa quality assessment tool. The pooled prevalence of obstructive lung patterns and actual spirometric results were estimated using effect size and standardized mean differences (SMD).

Results

A total representative of 3511 participants was included in this study. The pooled prevalence of obstructive lung patterns in occupational exposure at different workplaces was found 13.04% (95% CI: 7.96, 18.12, I 2 = 89.2%). On the other hand, the pooled prevalence of obstructive lung patterns in controls was 4.10% (95% CI: 1.86, 6.34, I 2 = 76.8%). SMD of spirometric results was significantly decreased in cases as compared to the controls. The SMD of FVC in a litter (L) at 95% of CI: -0.50 (-0.70, -0.30, I 2 = 87.7%), SMD of FEV1 in (L) at 95% CI: -0.54 (-0.72, -0.36, I 2 = 84.9%), SMD of FEF25%-50% in litter per second (L/s) at 95% of CI: -0.42 (-0.67, -0.17, I 2 = 81.9%) and SMD of PEFR in L/s at 95% CI: -0.45 (-0.68, -0.21, I 2 = 78.4%) were significantly decreased in cases as compared to the controls.

Conclusion

The pooled prevalence of obstructive lung pattern was higher in people who are working at different workplace that generating dusts and chemicals. The SMD of actual spirometric results were reduced in cases than controls. Therefore, to alleviate this problem appropriate preventive measure would be warranted for those people who are working in different dust and chemical generating environments.

Frequency of respiratory symptoms among rice mill workers in Bangladesh: A cross-sectional study

Background and Aims

Rice mill workers are frequently exposed to rice dust specks containing bacteria, endotoxins, spores, and chemicals in workplaces. Consequently, they develop diverse respiratory symptoms that lead to increased disability and social burden. The present study was conducted to observe the frequency of respiratory symptoms among rice mill workers in Bangladesh.

Methods

This cross-sectional study was conducted at different rice mills in Rangpur district of Bangladesh. Three hundred and forty-six rice mill workers, both male and female of 18 years and above, with a job experience of at least 3 years, were selected as study subjects. An equal number of people who had never worked at rice mills were selected from the nearby locality as the nonexposed group. Enquiries were made regarding respiratory symptoms with the help of a preformed questionnaire which contained sociodemographic characteristics, occupational history, potential confounding factors, and physical parameters. A respiratory dust sampler was used to measure workplace dust concentration.

Results

The presence of one or more respiratory symptoms was significantly higher among rice mill workers than in the nonexposed group (52.3% vs. 17.6%). Rice mill workers who worked for more than 10 h and had a working experience of more than 15 years had a higher frequency of respiratory symptoms (41.3% and 39.8%, respectively). Rice mill workers with body mass index (BMI) <18.5 also exhibited more respiratory symptoms (25.4%). All working sections had a higher-than-average dust concentration level, with the milling section being the dustiest (PM 2.5 492.1 µg/m3).

Conclusion

This study showed an increased frequency of respiratory symptoms among rice mill workers of Bangladesh. Longer working experience and working hours, low BMI and high dust concentration levels were strongly associated with that increase in frequency.

Effect on pulmonary functions of dust exposed rice mill workers in comparison to an unexposed population

BACKGROUND

Paddy milling is the oldest and largest agro-processing industry in India. A large number of workers are employed in the rice mills where they are potentially exposed to dust. It has been shown that exposure to dust results in a high prevalence of respiratory diseases, such as asthma, chronic bronchitis, extrinsic allergic alveoli ties, toxic syndrome, and interstitial lung disease.

OBJECTIVE

The aim of this study was to investigate the effect of dust on rice mill workers' health using lung function tests with comparison to an unexposed population.

PARTICIPANTS

Two hundred eighteen rice mill workers (exposed volunteers) were randomly selected from 25 rice mills in Assam, India. Participants were 18-60 years with at least one year of work experience. Further, 377 volunteers who were not exposed to dust and having similar demographic characteristics also participated as a control group.

METHOD

Pulmonary function tests were conducted for all participants by spirometry. The tests included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC (%), peak expiratory flow (PEF) and forced expiratory flow during the middle half of a forced vital capacity (FEF25-75%). Values from exposed workers were compared with the unexposed volunteers.

RESULTS

It was observed that the lung function parameters FVC, FEV1, PEF and FEF25-75% in exposed workers were significantly decreased compared with unexposed volunteers. There were also significantly decreased FVC, FEV1, FEV1/FVC%, PEF and FEF25-75% with increase in age and duration of dust exposure. It was further observed that 48% and 32% of the total male and female volunteers, respectively, had evidence of lung disease. Irrespective of gender, approximately 45% of mill workers had evidence of lung disease, of which 21% was restrictive and 24% was obstructive.

CONCLUSION

Compared with unexposed controls, rice mill workers have a greater prevalence of respiratory disease based on pulmonary function tests.

Respiratory symptoms related to flour dust exposure are significantly high among small and medium scale flour mill workers in Ethiopia: a comparative cross-sectional survey

BACKGROUND

International Labour Organization (ILO) report indicates more than 2.4 million workers die from work-related diseases and accidents each year. Work-related respiratory ailments related to airborne particulate matter such as flour dust are responsible for about 386,000 deaths and 6.6 million illness-adjusted life years. Even though exposure to flour dust together with the extreme expansions of flour mill sectors is a priority health concern, extent of the problem is little investigated in Ethiopia. The aim of this study was to evaluate the magnitude and risk factors of work-related respiratory symptoms among flour mill workers in Bahir Dar City, Ethiopia.

METHODS

This study employed a comparative cross-sectional survey of 560 samples (280 exposed group from flour mill workers and 280 unexposed group from office workers) with a stratified random sampling technique. The study was conducted from March to April 2019 in Bahir Dar City, Northwest Ethiopia. We used the British Medical Research Council (BMRC) questionnaire to assess work-related respiratory symptoms. The questionnaire was pretested and interview administered to collect data. Binary logistic regression analysis was fitted to evaluate significant factors of respiratory symptoms at a < 0.05 p value. Adjusted odds ratio (AOR) with a confidence interval (CI) of 95% was calculated to determine a strength of association.

RESULTS

All the sampled participants had fully responded to the interview. The median age of exposed and unexposed groups was 28.5 interquartile range (IQR, 20) and 31 (IQR, 15) years, respectively. The prevalence of work-related respiratory symptoms among flour mill workers was substantially higher than that of among controls, 63.9% and 20.7%, respectively (Χ2 = 107.11; p < 0.0001). Chest illness among flour mill workers was higher, 43.6% (N = 122) compared to that of among control group, 7.9% (N = 22) followed by dyspnea, 33.6% (N = 94) versus 2.5% (N = 7) among flour mill workers and control group, respectively. Age > 35 years [AOR, 2.03; 95% CI (1.34, 5.48), having no education [AOR, 1.54; 95% CI (1.28, 3.06)], work set up with inadequate ventilation [AOR, 2.05; 95% CI (1.18, 3.56)], work experience > 5 years [AOR, 1.89; 95% CI (1.23, 4.67)] and having no training in safety [AOR, 2.45; 95% CI (1.45, 4.76)] significantly affected the experience of respiratory symptoms among flour mill workers whereas age [AOR, 1.79; 95% CI (1.06, 3.04)], monthly salary [AOR, 1.98; 95% CI (1.04, 3.78)] and exposure status [AOR, 5.18; 95% CI (3.34, 8.04)] were detected to be significant factors of respiratory symptoms in the exposed and the unexposed combined model.

CONCLUSION

Respiratory symptoms emanating from exposure to various flour dusts were significantly higher among flour mill workers than among the control group. Therefore, we recommend the need to effectively implement health and safety programs that account for the reduction of dust at a source, use of engineering controls (e.g., provision of adequate ventilation systems), use of administrative measures (e.g., training program and health surveillance) and provision of a suitable personal protective equipment (PPE). Furthermore, it is vital to integrate workplace health and safety programs to the wider public health policies and strategies to effectively mitigate the burden of work-related respiratory conditions. We also encourage future studies to evaluate concentration of flour dusts combined with physical examinations to establish plausible associations of respiratory symptoms with dusts of flour mill-related origin.

Longitudinal predictors of bronchial hyperresponsiveness and FEV1 decline in bakers

OBJECTIVE

To determine long-term predictors of bronchial hyperresponsiveness (BHR) and forced expiratory volume in one second (FEV₁) decline.

METHODS

A longitudinal study in 110 bakers in 4 industrial bakeries and 38 non-exposed workers was conducted at the workplace with a mean of 3.3 visits per subject over a period of 13 years and a mean duration of follow-up of 6 years in bakers and 8 years in non-exposed subjects. A respiratory health questionnaire was administered; occupational allergen skin prick tests, spirometry and a methacholine bronchial challenge test were performed at each visit. In each bakery, full-shift dust samples of the inhalable fraction were obtained in order to assess the exposure of each job assignment. The repeated measurements of BHR and FEV₁ were analyzed using mixed effects logistic and linear regression models in subjects seen at least twice.

RESULTS

BHR, respiratory symptoms and their simultaneous occurrence depended on the duration of exposure. FEV₁ significantly decreased with duration of exposure and BHR at a preceding visit. This result persisted when adjusting for the effect of BHR at the current visit. The measured exposure levels were not a significant predictor for any outcome. Occupational sensitization was only a predictor of a decline in FEV₁ when duration of exposure was not included.

CONCLUSION

In flour-exposed industrial bakers, length of exposure and smoking are long-term determinants of BHR and of the decrease in FEV₁. BHR at a preceding visit predicted lower FEV₁ even when accounting for the effect of BHR at the current visit.

Chronic respiratory symptoms, lung function and associated factors among flour mill factory workers in Hawassa city, southern Ethiopia: "comparative cross-sectional study"

Background

Occupational related respiratory diseases arise as a result of the deposition of dust particles in the lungs. Flour milling industries; generate organic dust during industrial processes, such as cleaning, milling, packaging, and loading which release dust into the air and later inhaled by workers. Flour mill workers are at risk of developing respiratory health problems because of exposure in their working environment, but existing data were few. The aim of this study was to assess the prevalence of chronic respiratory symptoms, lung function and associated factors among flour mill factory workers.

Methods

A comparative cross-sectional study was conducted among 196 flour mill factory workers and 210 soft drinks factory workers. We selected study participants using a systematic sampling technique. We assessed the chronic respiratory symptoms using the questionnaire adopted from the British Medical Research Council. Binary logistic regression analysis with 95% CI and p < 0.05 was used to identify the factors. Lung function parameters; Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1) and ratio FEV1/FVC was measured by using spirometer and analyzed by using an independent t-test.

Results

We included 406 (96.7%) workers in this study. The prevalence of chronic respiratory symptoms was higher among flour mill workers as compared to soft-drinks factory workers (56.6% vs.12.9%). Primary education (AOR = 5.8, 95% CI, 1.3–23.2), mixing department (AOR = 5.3, 95% CI = 1.68–16.56), work experience 6–9 years (AOR = 5.1, 95% CI = 2.05–12.48), work experience ≥10 years (AOR = 2.5, 95% CI = 1.01–6.11) and working over eight hours (AOR = 2.4, 95% CI, 1.16–5.10) were factors that significantly associated with chronic respiratory symptoms among flour mill workers. FVC (p < 0.002), FEV1 (p < 0.001) and FEV1/FVC (p < 0.012) were significantly reduced among flour mill workers.

Conclusions

We found chronic respiratory symptoms to be high among flour mill workers. Lower education level, mixing department, increased work experience, and longer working hours were identified factors. The flour mill dust exposed worker’s lung function parameters were highly reduced. This study suggested that workers’ dust exposure reduction and control methods in flour mill factories need to be implemented.

Effect of Particulate Matter Exposure on Respiratory Health of e-Waste Workers at Agbogbloshie, Accra, Ghana

Background: Direct and continuous exposure to particulate matter (PM), especially in occupational settings is known to impact negatively on respiratory health and lung function. Objective: To determine the association between concentrations of PM (2.5, 2.5–10 and 10 µm) in breathing zone and lung function of informal e-waste workers at Agbogbloshie. Methods: To evaluate lung function responses to PM (2.5, 2.5–10 and 10 µm), we conducted a longitudinal cohort study with three repeated measures among 207 participants comprising 142 healthy e-waste workers from Agbogbloshie scrapyard and 65 control participants from Madina-Zongo in Accra, Ghana from 2017–2018. Lung function parameters (FVC, FEV1, FEV1/FVC, PEF, and FEF 25-75) and PM (2.5, 2.5–10 and 10 µm) concentrations were measured, corresponding to prevailing seasonal variations. Socio-demographic data, respiratory exposures and lifestyle habits were determined using questionnaires. Random effects models were then used to examine the effects of PM (2.5, 2.5–10 and 10 µm) on lung function. Results: The median concentrations of PM (2.5, 2.5–10 and 10 µm) were all consistently above the WHO ambient air standards across the study waves. Small effect estimates per IQR of PM (2.5, 2.5–10 and 10 µm) on lung function parameters were observed even after adjustment for potential confounders. However, a 10 µg increase in PM (2.5, 2.5–10 and 10 µm) was associated with decreases in PEF and FEF 25–75 by 13.3% % [β = −3.133; 95% CI: −0.243, −0.022) and 26.6% [β = −0.266; 95% CI: −0.437, 0.094]. E-waste burning and a history of asthma significantly predicted a decrease in PEF by 14.2% [β = −0.142; 95% CI: −0.278, −0.008) and FEV1 by 35.8% [β = −0.358; 95% CI: −0.590, 0.125] among e-waste burners. Conclusions: Direct exposure of e-waste workers to PM predisposes to decline in lung function and risk for small airway diseases such as asthma and COPD.