The present study revealed an overall prevalence rate of 8.7% for ORD among study participants with the highest prevalence in the utility sector. The significant factors associated with ORD are age, gender, marital status, nationality, race, levels of education, smoking status, vape user, history of medical illness, working hours per day, working space as confined, crowded space in addition to training on PPE and usage of PPE.
Prevalence of ORD
Our finding of 8.7% overall ORD prevalence in Malaysian workers positions itself within the global spectrum of occupational respiratory disease burden. This rate is substantially higher than the incidence of 2–5 cases per 100,000 population per year of occupational asthma15, but lower than the 51.6% prevalence found among Ethiopian industry workers16, industry workers in the UK (22%), Eastern Nepal (21.1%), Hong Kong (27.2%), and Bangladesh (34%)16. These disparities likely reflect differences in occupational safety regulations, with Malaysia’s intermediate position mirroring its developing economy status.
Prevalence of ORD in industrial sectors
The utility sector’s high ORD prevalence (22.4%) aligns with Ahmad & Balkhyour (2020)17, who reported 22.7% respiratory symptoms in gas industry workers due to toxic exposures. However, our findings exceed Leon-Kabamba et al. (2020)’s quarry worker study (4.5%)18, suggesting regional exposure disparities.
The construction sector emerged as the third highest-risk industry for occupational respiratory diseases (ORD) in this study after utility and mining. This finding aligns with research by da-Silva-Filho et al. (2019)19, who reported that 44.4% of construction workers exhibited respiratory symptoms—primarily persistent cough, phlegm production, and wheezing—due to prolonged exposure to airborne hazards. A critical contributor to ORD in this sector is particulate matter (PM) generated from activities like demolition, drilling, and material handling, which accounts for 70–80% of total PM emissions at construction sites20. Notably, construction-related PM contains silica, heavy metals, and organic compounds, which are linked to asthma, bronchitis, and COPD19,20. These risks underscore the urgent need for stricter dust-control measures and respiratory protection protocols in construction environments.
This study reveals significant sector-specific variations in ORD risk, with manufacturing workers particularly vulnerable to emerging conditions like BADE21. Agricultural workers face compounded risks from pesticide/dust exposures, showing 2.3 higher asthma rates22. In contrast, wholesale/retail and hospitality sectors demonstrate lower risks17,23, aligning with their reduced exposure profiles. These findings underscore the need for sector-specific prevention strategies to address Malaysia’s 8.7% ORD prevalence.
Socio-demographic factors
Age
The workers in the industry have the chance of having ORD rise by 1.6 times with every year of age., this findings is similar to study done among steel workers7. Aging is a risk factor and prognostic indicator for acute respiratory distress syndrome, according to Brown, McKelvey24, with possible underlying mechanisms contributing to increased risk and severity. As we age, immune-senescence reduces our ability to fight infections, leading to prolonged inflammation that worsens lung injury and accelerates ARDS progression24.
Gender
The men workers in the industry have the chance of having ORD more than women, this findings is similar to study done in farming cohort25. However, women show greater susceptibility and severity in certain respiratory diseases26. For example, women are more likely than men to develop chronic obstructive pulmonary disease (COPD)26. The disparity is influenced by sociocultural factors, occupational segregation, and underestimation of women’s occupational exposures and related diseases25,26.
Married status
Research indicates that married individuals have a higher risk of getting ORD than unmarried. Saupin, Hayati27 found that Malaysian construction workers who were exposed to dust, and experienced ORD symptoms along with divorce, separation, or being widowed are more likely to have ORD than married or single. The study suggests further research is needed to better understand the link between respiratory health and marital status among industrial workers27.
Nationality
Malaysian respondents are more susceptible to experiencing ORD compared to non-Malaysians. The high prevalence of Malaysian respondents (89%) compared to foreigners (11%) further reinforces this finding. Study conducted by11 highlighted that workers in Malaysia face significant occupational health risks, especially in regions undergoing fast industrialization. The study emphasised that respiratory infections are a significant health concern among Malaysian workers, underscoring the need for improved workplace safety measures and healthcare interventions11.
Races
The analysis suggests that Chinese, Indian, and Malay workers appear to be less likely to develop occupational lung diseases (odd ratios 0.28, 0.3, and 0.61, respectively). Most studies on racial disparities in occupational lung diseases focus on groups such as African-Americans, Hispanics, and Whites, showing that minority groups in the US often have higher occupational exposures and worse respiratory outcomes due to socioeconomic and environmental factors rather than inherent racial susceptibility28,29. Research indicates that racial/ethnic disparities in occupational exposure and respiratory disease risk are largely driven by social determinants such as job types, income, education, and access to healthcare, rather than race itself as a biological risk factor30.
Levels of education
There was a significant relationship between the level of education and ORD, whereby people with a higher education level were more likely to develop ORD. This finding is contrary to the expectations of the theory that increased education reduces the occurrence of ORD31,32. However, a study among schoolteachers found that teachers are at high risk of ORD33. One possible explanation for the connection is that employees with tertiary education might be engaged in hazardous occupations, increasing their chances of being in contact with toxic substances. These exposures considerably raise their vulnerability to respiratory diseases; hence the call for tight safety measures and constant health check-ups.
Smoking status
From the study, the odds of a respondent being a smoker are higher compared to those who do not smoke. Smoking impairs immune function, reduces mucociliary clearance, and causes airway inflammation, which heightens the risk of acute respiratory infections and worsens outcomes in occupationally exposed workers34. This finding is consistent with multiple research that highlights the substantial influence of smoking on the respiratory well-being of industrial workers7,35. This highlights the importance of enacting smoking cessation programmes and establishing safety measures in the workplace27.
Vaping status
Vaping significantly increases the likelihood of developing ORD, consistent with research showing its adverse respiratory effects. A study conducted a comprehensive investigation into cases of lung injury associated with the usage of e-cigarettes or vaping products, commonly referred to as EVALI36 The study highlighted that a significant fraction of EVALI patients disclosed the consumption of items containing tetrahydrocannabinol (THC), leading to a major proportion of them requiring hospitalisation as a result of ARDS36.
Medical illness
Regarding studies on occupational respiratory diseases, research by De Matteis, Heederik15 suggests that individuals with previous medical history are significantly more susceptible to acquiring ORD. This observation aligns with numerous other studies that have emphasised the correlation between existing medical conditions and respiratory well-being in work settings. Additionally, it emphasised the hazards linked to work risks for employees who had preexisting respiratory conditions15,37,38.
Occupational factors
Working hours per day
Employees working more than 12 h a day stand the highest risk of developing the disease, followed by those working less hours. Long working hours were a risk factor that was brought out clearly by the COVID-19 pandemic by Mhango, Dzobo39 who discovered that long working hours predisposed healthcare workers to COVID-19. This means that several respiratory diseases are likely to occur as a result of high and prolong exposure to inhalable pollutants arising from long working hours39.
Workspace (confined, crowded)
Confined and crowded environments at the workplace increase the spread of respiratory diseases among employees. Moon and Ryu40 conducted a meta-analysis and found that workplaces are significant areas for respiratory infection transmission. The study concluded that it might increase the risk of ORD because of poor ventilation, close contact between workers, and shared indoor air. These are the basic characteristics of enclosed workplaces that increase the risk of transmission of respiratory diseases40,41.
Organizational factors
Training in PPE
Numerous study shows that workers who underwent PPE training have a lower risk of developing ORD. Studies conducted between 2020 and 2024 during emergence of pandemic COVID19 have stressed the significance of PPE training in enhancing the safety levels of employees and preventing the spread of respiratory diseases at the workplace42.
Usage of PPE
Ensuring compliance with PPE protocols is essential for protecting worker’s health and reducing ORD. Houghton, Meskell43 studied factors affecting industrial workers’ compliance with PPE and highlighted the importance of using PPE and mandatory training to enhance compliance. The challenges identified insufficient training and inconsistent utilisation of PPE, leading to an elevated infection rate among staff. Hence, there is an urgent need for adequate training and instruction to encourage the appropriate use of PPE43.
Study limitation
While this study provides valuable insights, it is crucial to acknowledge its limitations. The utilisation of self-reported data obtained through an online questionnaire increases the probability of recall bias and social desirability bias. Furthermore, it is important to acknowledge that the use of a cross-sectional design in this study restricts the capacity to establish causal connections between suspected ORD and its associated components. Additionally, as this is a test specifically for symptoms, it is recommended to undergo further screening if there is suspicion of an underlying medical condition. Employing spirometers and lung function testing is advised as supplementary means to assess the respiratory well-being of the workforce. Longitudinal or prospective designs are more appropriate for future research on the temporal relationship between occupational exposures and the development of suspected ORD44.
Recommendation
To address the high prevalence of occupational respiratory diseases (ORD), prioritize further investigation, risk assessment and interventions in high-risk sectors such as manufacturing, utilities, construction, and mining by enforcing strict occupational health and safety (OSH) regulations, improving workplace ventilation, and mandating proper use of personal protective equipment (PPE). Conduct regular training on PPE use, monitor compliance, and offer incentives for adherence. Implement health-focused measures, including smoking and vaping cessation programs and regular medical screenings for at-risk workers, particularly those with pre-existing illnesses. Redesign workspaces to reduce crowding, advocate for policies limiting long working hours, and tailor interventions for older, male, and married workers who are at higher risk. Increase awareness of OSH through targeted campaigns and develop sector-specific guidelines while ensuring inclusivity across ethnic groups. Establish feedback mechanisms for reporting unsafe conditions and continuously update the NODIP database to monitor ORD trends and intervention effectiveness.
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