Introduction

Currently, occupational-related injuries and illnesses are a global public health concern. Although waste collection has been contributing greatly to human health by reducing the risk of several infectious diseases, solid waste collectors are at high risk of fatal and non-fatal injuries.¹

Working conditions for the majority of the 3 billion workers worldwide do not meet the minimum standards and guidelines set by the World Health Organization and the International Labour Organization (ILO) for occupational health and safety.^2–5 According to the most recent ILO global estimates of occupational accidents and work-related illnesses in 2017, there were an estimated 2.78 million fatalities in 2017, compared to an estimated 2.33 million in 2011.^2–5

For fatal occupational accidents, there were 380 500 deaths, an increase of 8% in 2014 compared to 2010. Fatal work-related diseases have been a concern since 1998 and are at least 5 times higher than fatalities due to occupational accidents.^2–5 In 2015, there were 2.4 million deaths due to fatal work-related diseases, an increase of 0.4 million compared to 2011. In Africa, there was the highest fatality rate, which accounted for 16.6 per 100 000 people in the Labour force. However, 374 million people are injured each year, resulting in more than 4 days missed from work, and occupational accidents cost 4% of global gross domestic product (GDP), including lost workdays, production interruption, retraining, and medical expenses.^2–5

This problem is high in developing countries,⁶ where about 80% of workers are employed in unsafe work environments and only 5% to 15% have access to occupational health services.⁷ Because waste management procedures in developing countries majorly involve manual handling of the waste.⁸ In sub-Saharan Africa, 54 000 workers die, and 42 million work-related accidents each year.⁹ However, the problems might be higher than this report as the result of low levels of reporting injuries in most of the developing countries.^4,10,11 Solid waste collectors face occupational health and safety risks around the world due to the materials they handle, the wastes they collect, and the equipment they utilize.¹² Joint and spinal injuries, fractures, puncture wounds, and damage to the eyes and ears are just a few of the injuries that can occur. Slides from unstable disposal piles, cave-ins of disposal site surfaces, fires, explosions, being caught in processing machinery, and being run over by mobile equipment are only some of the accidents that can happen. Collection, recycling, processing, and disposal technologies are all considered in relation to solid waste management.¹² For example, in Brazil’s Social Security data registered a total of 2 152 524 accidents nationwide for all classes of workers in the period between 2011 and 2013. For workers collecting, treating, or disposing of domestic and/or dangerous waste, 27 460 accidents were registered nationwide in the same period, representing less than 1% of the total. Only in 2013, with 7056 registered cases, accidents registered by workers collecting non-dangerous waste were the 14th most frequent type in that year compared with all other registered activities.¹³

In Ethiopia, municipal solid waste workers collect waste door to door and from commercial areas that needs to be shoveled by hand, picked up by hand or emptied from sacks in which the workers have direct contact with solid waste, and exposed to strenuous working conditions.^14,15 The above facts indicate that workers have direct contact with solid waste, and are also exposed to strenuous working conditions. These workers have used less personnel protective equipment, and most municipal solid wastes are not safely contained in liftable load sizes. Besides these problems, there is inadequate evidence on the prevalence of occupational-related injuries and determinant factors among municipal solid waste collectors (MSWC).¹⁶ Occupational related studies are not adequate given that the possible exposure of workers to various work related hazards might exist.¹⁴ This indicates that there is a strong need to generate evidence on the occupational injuries of solid waste collectors to know the extent of the problems in Harar town.

This study was aimed to determine the prevalence of occupational injuries and associated factors among municipal solid waste collectors. The finding of the current study can be used by the concerned organizations, including policy makers, and health program planners to take an appropriate measure to minimize the severity of occupational injuries and associated risk factors. It can also vital for designing mechanisms to resolve the gap for concerned stakeholders.

Materials and Methods

Sample size determination

Sample size was calculated based on the pervious reported prevalence (63.9%) in Ethiopia¹³ with a 95% confidence interval of, z = 1.96 and 0.05 margin of error (d)=, q = 0.361. Furthermore, 10% non-response rate was also considered. Finally, 389 sample was obtained using the equation bellow.¹⁷

Results

Socio-demographic Characteristics

Of 389 solid waste collectors, 381 were interviewed, with a response rate of 98%. Among the interviewed, 223 (58.5%) were females. The median age of respondents was 38 ± interquartile range (IRQ) of 12 years. Two hundred forty-three (63.8%) were married, and 214 (56.2%) were illiterate (Table 1).

Table 1.

Socio-demographic characteristics of municipal solid waste collectors in Harar town, Eastern Ethiopia, from May 25 to June 25, 2021 (n = 381).

Behavioral and work-related characteristics of respondents

Two hundred fifty-five (66.9%) of the study participants were working more than 5 days per week. Among respondents, 204 (53.5%) respondents had personal protective equipment (PPE), of which 185 (90.7%) were using PPE. Furthermore, 93 (24.4%), 203 (53.3%), and 82 (21.5%) of the participants had a history of alcohol consumption, chewing khat, and smoking cigarettes, respectively (Table 2).

Table 2.

Work-related environment and behavioral characteristics of municipal solid waste collectors in Harar town, Eastern Ethiopia, May 25 to June 25, 2021.

Prevalence of occupational injuries among respondents

Of 381 solid waste collectors, 230 (60.4%) were exposed to occupational related injuries in the last 12 months, of which 184 (80%) sustained injuries more than once and 109 (28.6%) were exposed in the last 1 month.

The most common body parts exposed to injury were the hand, leg, and back, which accounted for 237 (56.8%), 85 (20.4%), and 83 (19.9%), respectively. Furthermore, 175 (76.1%) participants were exposed to injuries in the last 12 months (Table 3).

Table 3.

Distribution of occupational injury and injured body parts in the last 1 year among solid waste collectors in Harar town, Eastern Ethiopia, from May 25 to June 25, 2021 (n = 381).

The most prevalent types of occupational injuries among solid waste collectors were cut 140 (29.9%), abrasion/laceration 120 (25.6%), and back pain 78 (16.7%) (Figure 1).

Figure 1.

Types of occupational injuries of municipal solid waste collectors of Harar town, Eastern Ethiopia.

The research shows that this group of workers were severely injured while collecting waste, 173 (38.8%). Transferring waste from the household’s receptacles as well as picking openly discarded waste from the ground are examples of these activities. Following that, there were 121 (27.1%) lifting rubbish, 120 (26.7%) loading tracks, and 16 (3.6%) unloading tracks. Other tasks include loading the sacks or carts and sweeping the container’s area at the curb (Figure 2).

Figure 2.

Types of activities or causes of injury for Harar town municipal solid waste collectors, Eastern Ethiopia.

Factors associated with occupational injuries

The current study found that workers who completed primary education had an 89.8% lower risk of occupational injury [AOR = 0.102 (95% CI: 0.028-0.375)]. Furthermore, when compared to the illiterate, workers with a secondary or higher education had a 96% lower risk of injury [AOR = 0.04 (95% CI: 0.030-0.452)]. Solid waste collectors who received health and safety training had a 90% lower chance of being injured than those who did not [AOR = 0.10 (95% CI: 0.026-0.303)]. Furthermore, the use of on-the-job helped to prevent occupational injuries among solid waste collectors. When compared to their counterparts, PPE users had a 91.1% lower risk of harm [AOR = 0.089, 95% CI (0.017-0.457)] (Table 4).

Table 4.

Multi-variable logistic regression of occupational injuries in Harar town municipal solid waste collectors, Eastern Ethiopia, May 25 to June 25, 2021 (n = 381).

Discussion

The current study found that 230 (60.4%) of solid waste collectors were exposed to occupational injuries in the last 12 months, which was in line with the findings of other studies conducted in Egypt, which reported 64%,²⁴ and in Ethiopia, which reported 63.9%.¹⁵ However, it was higher than the finding reported by a studies conducted in Thailand, which reported 36.37%,²⁵ Tanzania which reported 40.90%,²⁶ Ghana 27.8%,²⁰ and in Ethiopia which reported 34.3%.¹⁰ The variation may be related to the difference in waste management systems or technology, work experience, application of occupational health and safety measures and services, or access to the PPE.

Furthermore, this study found that among 230 solid waste collectors exposed to work-related injury, 38.8% were exposed during waste collection, 27.1% during lifting waste, and 26.9% during loading waste. This finding was consistent with studies conducted in different regions of Ethiopia; Addis Ababa^10,14,15 which reported collecting waste (44.9%), followed by loading and lifting 79 (15.6%) and 71 (14.6%), respectively. But a study conducted in America in 2010 on solid waste collectors showed that lifting/pushing/pushing (22.5%) was the most common cause of injury, followed by falls (10.5%), repetitive motion (6.2%), and awkward body posture (6.2%).²⁷ The variation may be related to the difference in waste management practices, training, work experience, occupational health and safety measures in the study areas.

Regarding the body parts injured, the study found that the most common body parts injured were hands, legs, and back pain was 56.8%, 20%, and 19.9%, respectively. Similar findings were shown in Ethiopia, where hands (22.7%), legs (21.8%), and back pain (17.2%) were the most commonly injured parts of the body.¹⁵ Moreover, similar investigations carried out in Ethiopia revealed significant rates of injuries to the hands, legs, and back pain.^10,14 This might be due to the fact that most solid waste collectors (SWCs) manually collect waste then place it in sacks and trucks with their hands, increasing the risk of cuts and abrasions.¹⁴

Furthermore, solid waste collectors, particularly those participating in collecting, routinely use their hands and legs to compact waste in sacks for easy transportation. However, a study of solid waste collectors in the United States of America (USA) found that hands (12%), legs (6%), and back pain (20%) were the most frequent problems.²⁷ The discrepancy between hand, leg, and back injuries is due to the capacity of bins. In USA, they used litter bins located in parks and gardens which are more difficult to work with and required higher forces to push or pull a full wheel bin across soft or wet lawn, pine bark, mud or soil and the workers adopted awkward posture.^27,28 However, in this study, SWCs utilized non-puncture-proof sacks or bags. It might also be related to respondents’ lack of or underuse of PPE, since the majority of respondents stated that they do not use PPE all of the time owing to a lack of PPE or discomfort in using it.

In this study, the most frequent causes of work related injury were sharp and slender pointed objects (38.8%) during waste collection, lifting waste (27.1%), and loading waste (26.9%). This finding was consistent with some studies conducted in Ethiopia.^10,14,15 But, a study conducted in America in 2010 on solid waste collectors showed that lifting/pushing/pushing (22.5%) was the most common cause of injury, followed by falls (10.5%), repetitive motion (6.2%), and awkward body posture (6.2%).²⁷ The possible reasons are that sharp and slender pointed objects were the common causes of injury in this study as a result of sharp and slender pointed objects being disposed of with the general waste (mixed waste). Even workers who wore hand gloves during data collection did not wear PPE on a regular basis, and the community used punctured bags to store waste, exposing collectors susceptible to injury during waste collection and handling.

In this study, increasing educational levels have been associated with decreased occupational injuries compared to those who are not educated [AOR = 0.102, 95% CI (0.028-0.375)] and [AOR = 0.04, 95% CI (0.030-0.452)], respectively. This is consistent with studies conducted in Egypt, Rwanda, and Ethiopia.^15,29,30 Furthermore, solid waste collectors who had health and safety training before engaging in the job decreased the probability of injury occurrences by 90% compared to those who were not trained [AOR = 0.10, 95% CI (0.026-0.303)]. This finding was supported by another finding conducted in India and Ethiopia.^15,22

Furthermore, solid waste collectors with 1 and above year experience had 5.975 higher odds of occupational injury compared to those solid waste collectors with 1 year and less work experience. The finding of the current study was consistent with studies conducted in Tanzania, and Ethiopia.^15,26 Additionally, this study found that the use of personal protective equipment on the job sought to minimize solid waste collectors from suffering occupational injuries that was consistent with studies conducted in India, Egypt, Tanzania, and Ethiopia.^{14,15,19,22,26,29}

Conclusion

The results of this study concluded that a higher prevalence rate of occupational injury was reported in the study areas. This study identified that educational level, work experience, utilization of PPEs, and health and safety training were the predictor factors associated with occupational injury. In general, this data, as well as those from previous research, indicated that Harar had a greater frequency of occupational injuries. Before and after hiring solid waste collectors, employers should provide personal protective equipment (PPEs) and tailored training on safety measures.