Background

Occupational injuries are among the significant public health problems affecting millions of workers. The International Labor Organization (ILO) reported about 2.78 and 374 million fatal and non-fatal injuries, respectively per year globally.¹ Beyond mortality and morbidity, the global average economic loss due to occupational injuries was 4% of the Gross Domestic Product (GDP) in 2016.^2,3 The burden of occupational injuries, accidents, and diseases is high particularly among small scale enterprise workers.⁴ As they may be less educated, unskilled, untrained, and inexperienced with the tools and machine, there is an increased risk of occupational injuries among small scale enterprise workers as compared with large scale enterprise workers.⁴

The prevalence of occupational injuries among small scale enterprise workers is reported to be 10 to 20 times higher in developing countries than the developed counterparts.⁵ In African countries, where manufacturing is largely intense, the enforcement of occupational health and safety regulation is at its infancy which leads to greater magnitude and severity of occupational injuries.^6,7 For instance, studies conducted in Ghana⁸ and Zimbabwe⁹ reported prevalence of 40% and 41%, respectively. Indeed, the prevalence of occupational injuries could vary from place to place.

In Ethiopia, occupational injuries are also significant causes of mortality and morbidity among small scale enterprise workers.^4,10,11 Studies done in various parts of Ethiopia reported that the magnitudes of occupation injuries could be as high as 32.6% in Northeast Ethiopia,¹⁰ 45.2% in Southwest Ethiopia,¹² 39% in Northwest Ethiopia,¹³ and 30% in Southeast Ethiopia.¹⁴ A systematic review and meta-analysis in Ethiopia also revealed a 44.7% prevalence of occupational injuries among small scale enterprise workers.¹⁵

Most of the previous studies conducted on occupational injuries emphasized on construction or welding industry workers which could underestimate the real level of occupational injuries recorded in small scale industries.^{10,11,13,16–20} Conversely, others investigated the crude level of occupational injuries from both small scale and large scale industries.^21,22

Hence, considering various small scale enterprises including construction, furniture, metal workers, and concrete block construction workers will give a better estimate of occupation injuries among small scale enterprise workers. Therefore, this study aimed at determining the prevalence and predictors of occupational injuries among various small scale enterprise workers in Ambo town (Ethiopia). The findings of this study could help provide insights into possible intervention and appropriate control methods in the workplaces.

Methods and Materials

Source and study population

All the 953 small scale enterprise workers in Ambo town were the source population of the study. The 567 workers employed in randomly selected 172 small scale enterprises were the study population (Figure 1). Selected workers who were directly engaged in the production process of small scale enterprises during the data collection period were the study units.

Figure 1.

Sampling procedure for occupational injury and associated factors among small scale enterprise workers in Ambo town, Central Ethiopia, 2021.

Sample size determination

The sample size was computed using a single population proportion formula:

The assumptions of 95% confidence level (Z_α/2 = 1.96), proportion (p) of 1-year occupational injuries (45.2%), which was taken from a study conducted in Mizan Aman town,¹² and margin of error (d = 5.0%) were considered. By adding a 10% of none-response rate, the final sample size becomes 419.

Results

Socio-demographic characteristics of the respondents

Of 419, a total of 408 respondents have participated giving a response rate of 97.4%. More than one-third of the respondents (42.6%) were within the age group of 30 to 39 years and the great majority of the workers (97.8%) had less than 5 year experience in the same work. This study indicated that 65.4% of the workers were employed in the enterprises temporarily. Workers job category showed that 109 (26.7%) were concrete and block manufacturing workers, 91 (22.3%) were metal workers, 173 (42.4%) were wood workers, and 35 (8.6%) were construction workers (Table 1).

Table 1.

Socio-demographics characteristics of small scale industry workers (n = 408) in Ambo town, Central Ethiopia, 2021.

Working environment and behavioral factors

The current study revealed that about half of the workers were working more than 8 hours per day. From the total study participants, about two-thirds (64.9%) had not received any health and safety training and 51% of them did not use personal protective equipment while working. Similarly, 51.7% and 53.9% of the workers use alcohol and chew Khat, respectively (Table 2).

Table 2.

Working environment and behavioral factors among small scale enterprise workers (n = 408) in Ambo town, Central Ethiopia, 2021.

Prevalence of occupational injuries

In the current study, the prevalence of occupational injuries in the last 12 months was 39.5% (95% CI: 35-44). Of these, 71 (44.1%) of them were injured more than once. The prevalence of occupational injuries varied among the different categories of small scale enterprises; being 53.3% (wood), 39.4% (concert and block), 33.3% (metal), and 21.8% (construction). In relation to types of occupational injuries, more than half (52.2%) of the workers experienced laceration or punctures followed by eye injury (16.1%) and electrocution (14.3%). Among the 161 workers who experienced injury, 72 (44.7%) suffered severe injury (Table 3).

Table 3.

Prevalence and types of occupational injuries among small scale enterprise workers in Ambo town, Central Ethiopia, 2021.

Factors associated with occupational injuries

In the multivariable logistic regression analysis, age of the participants, absence of workplace supervision, working hour per day, working during the night shift, alcohol user, khat chewing, non-utilization of PPE, and lack of health and safety training were significantly associated with the occurrence of occupational injuries (Table 4). The odds of occupational injuries were 2.2 times higher among those who had a history of work engagement for more than 8 hours per day than others (AOR = 2.2, 95% CI: 1.61-4.95). Similarly, workers who had no workplace supervision were 2.5 times more likely to experience occupational injury than workers who had workplace supervision (AOR = 2.55, 95% CI: 1.23-5.28). Workers who had no health and safety training were also 2 times more likely to be occupationally injured than workers who attended training (AOR = 2.05, 95% CI: 1.26-4.37).

Table 4.

Factors associated with occupational injuries among small scale enterprise workers (n = 408) in Ambo town, Central Ethiopia, 2021.

The likelihood of occupational injuries was almost 2 times higher among workers who consumed alcohol than workers who did not consume alcohol (AOR = 1.95, 95% CI: 1.24-3.06). Once more, workers who did not use personal protective equipment were 1.5 times more likely to face occupational injuries than their counterparts (Table 4).

Discussion

The aim of this study was to assess the prevalence of occupational injuries and associated factors among small scale enterprise workers in Ambo town, Central Ethiopia. In the present study, the prevalence of occupational injuries in the last 12 months was 39.5% (95% CI: 35-44) which was comparable with the findings of other previous studies done in Ghana (40%),⁸ Zimbabwe (41%),⁹ Southeast Ethiopia (43.2%),¹⁴ Ethiopia (44.7%),¹⁵ Egypt (46.2%),²⁰ Japan (44.2%),²⁸ and Colombo (43.7%).²⁹ On the other hand, our finding was greater than these reported in Northeast Ethiopia (32.6%),¹⁰ Addis Ababa (14.7%),²² Southern Ethiopia (31.4%),²³ Norway (31.7%),³⁰ Nigeria (13.5%),³¹ and Brazil (5.6%).³² However, the figure reported in the present study was lower than the study findings in Uganda (87.9%),¹⁶ India (49.7%),³³ and Iran (75.4%).³⁴ These disparities might be subjected to variations in socio-economic, demographic, and behavioral characteristics of the study participants, and institutional (enterprises) setups.

The burden of occupational injuries varied among small scale enterprises. These in the wood industry were most exposed, which is congruous with other finding reported in Northern Ethiopia.⁴ Once more, nearly half of the small scale enterprise workers had experienced occupational injuries 2 and more times. Our finding is far greater than the report from Addis Ababa, which found that only 3.2% of workers got injured twice or more.²² This difference might be associated with the fact that the present study included various small scale enterprises and the location of our study area, which is a small town compared to Addis Ababa.

The present study indicated that the risk of occupational injury increases with age of the workers. Another study conducted in Gondar (Ethiopia) also reported that older workers, compared with the youngsters, are more susceptible to occupational injury.¹⁸ Aging process encompasses series of physiological changes to the body that could make construction, wood, cement, and metal tasks very difficult for older people. The strength of a person to carry out physically demanding tasks effectively reduce as one gets older.

Furthermore, this study indicated that the odds of experiencing occupational injury were almost 2 times higher among those who work for more than 8 hours per day than those who work for less than or equal to 8 hours per day. This is consistent with other findings reported in Northern Ethiopia,⁴ Southwest Ethiopia,¹² USA,³⁵ Bangladesh,³⁶ and Nigeria.³⁷ The possible explanations include stress, loss of attention, and drowsiness, which could increase the chance of errors, risky behaviors, and hence poor compliance with the safety procedures.

Workplace supervision was also identified as an important predictor of occupational injury. In our study, those workers who did not follow any supervision were 2.55 times more likely to be occupationally injured than others. This finding is similar with studies done in Southwest Ethiopia,¹² Northern Ethiopia,²¹ and Southern Ethiopia.²³ This could be related with the fact that regular workplace supervisions could inform workers about health and safety, and help easily identify workplace hazards.²³

The occurrence of occupational injury was significantly associated with occupational health and safety training. The odds of occupational injury were 2 times higher among workers who had no training about occupational health and safety than workers who attended training. This is really alarming as 64.9% of the workers in this study reported the absence of occupational health and safety trainings. This result was consistence with other studies done in Dessie,¹⁰ Gondar,¹³ Kenya,³⁸ and Iran.³⁹ The findings generally suggest the importance of regular trainings in enhancing the skills of industry workers, and hence potentially reducing occupational risks.

Once more, workers who consume alcohol and chew khat were about 2 times more likely to be occupationally injured as compared to their counterparts. This is possibly associated with the effects of addiction-associated negligence and carelessness to avoid injuries. Similar findings were also reported in southern Ethiopia⁴⁰ and northwest Ethiopia.⁴¹

Our results revealed that workers who did not use personal protective equipment were 1.5 times more likely to experience occupational injury as compared to their counterparts. Other studies conducted in northern Ethiopia,⁴ Dessie (Ethiopia),¹⁰ Addis Ababa,¹¹ Southeast Ethiopia,¹⁴ Kenya,³⁸ and Pakistan⁴² also reported the importance of PPE in reducing occupational exposures. This is associated with the fact that whenever workers do not use PPE due to absence of supply or discomfort, they will become more prone to occupational exposures and injuries.

Limitations of the Study

As this cross-sectional study was based on self-reported occupational injuries, the results were possibly liable to social desirability and recall biases. Detailed analysis of ergonomic injuries is also not included. In addition, as ordinary logistic regression might have overestimated the association, generalized linear modeling with modified Poisson regression and robust variance would have been the most appropriate analysis.

Conclusions

More than one-third of the small scale enterprise workers experienced occupational injuries during the last year. The highest prevalence of occupational injuries was observed among wood workers. Being aged (older than 40 years), working for more than 8 hours per day, working during the night time, lack of workplace supervision, addiction (alcohol use and khat chewing), non-utilization of PPE, and lack of health and safety training were found to significantly increase the likelihood of occupational injuries. Therefore, the enterprise owners and other stakeholders should provide continuous health and safety training and personal protective equipment for workers with regular workplace supervision. Working load should also be considered to reduce the risk of occupational injuries. Workers should also properly utilize personal protective equipment and keep themselves away from alcohol and Khat addictions. In a wider context, labor policies – including regulatory frameworks to inspect working conditions – and social dialogs among small scale enterprises and employees are recommended.