Abstract
Keywords
Background
A healthy workforce is a key productivity asset of a country [1]. According to the International Labour Organization, in each year an estimated 2 million of the world’s workforce die from work-related diseases and nearly 0.32 million people die from occupational accidents. The figures for non-fatal work-relateddiseases exceed 160 million per year while non-fatal occupational accidents are estimated to be 317 million per year [2]. The number of fatal accidents is estimated to be decreasing in industrialized countries and increasing in developing countries [3].
Sri Lanka is among the many developing countries that have a considerable number of small-scale industries and a large number of workers who are working in various occupational settings. Small-scale industry workers are a specific group of people who work under different conditions and work settings [4]. The majority of these workers are in the low socio-economic category and are poorly educated. Due to these factors, employers can exploit the workers exposing them to various occupational hazards. In addition, due to lack of knowledge, these workers may be unaware of the risks to which they are exposed and unable to avoid adverse effects [5]. It is known that the employees of small-scale industries rarely benefit from existing occupational health and safety provisions [6]. Since the profession of industrial hygiene is still not currently recognized in Sri Lanka and the occupational health and safety legislation is not well developed in the country, it is a common belief that a majority of these workers are exposed to occupational hazards and are at a great risk of developing diseases related to their occupation. Furthermore, their ill health is compounded by various socioeconomic factors such as poverty, lack of education, poor working conditions, excess working hours, and poor diet [6, 7].
Although occupational health is an important area of workers’ health, there is paucity of data on major health issues among workers of small-scale industries in Sri Lanka. Therefore, it is important to identify health issues among workers and other related issues in the working environment in small-scale industries in order to plan occupational health services for workers. If the workers are made knowledgeable of the risk factors and methods of overcoming them, they would be able to avoid adverse effects of risk factors in occupational settings. The aim of this paper is to identify occupational health issues faced by small-scale industry workers in Sri Lanka that will be useful in planning interventions.
Methods
Study population
This study was conducted among workers in sele-cted small-scale industries in Gampaha (1386.6 km2) and Kalutara (1606 km2) districts in Sri Lanka. The study population were workers in four selected small-scale industry categories, namely food and beverages, apparel, non-metallic mineral products, andfabricated metal products. Since there was no unanimous agreement about the definition of the size of a small-scale industry [8], it was defined as a work setting with less than 20 workers. This was in agreement with most criteria which defined it between 1–50 workers [9].
Sampling method
A representative sample of the study population was selected using a two stage cluster sampling method [10]. For the first stage of the sample, the worker strength in the selected four divisions of small-scale industries in each district was listed out separately based on 2003/2004 census data. The number of workers from each division for each district was calculated proportionate to the total number of small-scale industry workers in each division. Thereafter, the number of clusters for each industrial division was calculated based on eight from each cluster. For the second stage, using the lists prepared by the Census and Statistics Department Sri Lanka (which indicates the small-scale industry divisions separately in Kalutara and Gampaha districts), clusters from each industry division were selected randomly by generating random numbers. A sample of 800 small-scale industry workers were estimated by including 80 clusters with eight subjects randomly selected in each cluster (with a design effect of 2 and, 5% non-response rate). Trained data collectors visited each identified cluster and collected the necessary data.
Measurements
The interviewer administered questionnaires used in the study consisted of two parts. Part one consisted of the details regarding the small-scale industry. The second part consisted of details of the selected workers in each small-scale industry. Details about the basic socio-demographic variables, lifestyle risk factors, characteristics of the occupation (experience in the present designation, number of working hours per day, average number of working hours per week, average monthly salary, average monthly income, basis of the payment, prior training, supervision at the work place, safety practices at the work place), and health issues the worker had in the past 12 months was collected. Pre-existing health issues of the workers were also collected in the same questionnaire. Health issues were collected under general categories (irritations, burns, visual and hearing problems) and more specific musculoskeletal problems related to the body regions (shoulder pain, wrist pain, knee pain, neck pain, backache). Duration of each health issue was carefully recorded in days.
Analysis
All analyses were performed using SPSS version 16. Usual descriptive statistics were used to summarize the raw data. Each analysis used participants with complete data on the relevant variables. Results were presented as percentage prevalence with 95% confidence limits where relevant.
Ethics
The University of Colombo Research Ethics Committee, Sri Lanka, approved the study.
Results
Characteristics of the participants
Sri Lanka is divided into 25 administrative districts. Our study surveyed 198 industries of the two districts selected. A total of 102 small-scale industries were surveyed in Gampaha district and 96 were surveyed in Kalutara district. Table 1 shows the characteristics of the participants selected for the study. The majority of the participants were from Food industry (42.8%) and the lowest number of participants were from Metallic industry (11.8%). Kalutara district had more participants from Apparel industry. The majority of the participants were between 20 to 39 years. Most of them were males (57.4%) and the majority of the participants were married. In relation to the socio-economic status, most participants had level of education more than grade 8 and the majority were earning a salary of Rs. 10,000 to Rs. 20,000. More than 75% of them were living in their own house. There were 28.4% regular smokers (ever) among the participants and nearly 50% of this number were current smokers. The number of participants using (any form and quantity of alcohol) was about 22.6%. Out of that about 40% of them reported using alcohol daily.
Characteristics of the occupation
Table 2 shows the major characteristics of the occupations of the participants of the study. There were very few participants (8.7%) with more than 5 years of experience in the present designation. Nearly 46% had experience of less than one year. The majority of the participants (62.1%) were working 8 hours per day. Another three quarters of them reported working 8–12 hours per day. There were 16.7% participants reported working in shift work and, more than half of the shift workers engaged in both day and night shifts. Most of the participants were paid based on the working hours (62.6%) and were not given prior basic job training (85.8%). However, at most work places, job supervision was available (90.5%). Most of the participants (68.5%) reported that they were not following safety practices at work places although job supervision was available.
Selected occupational health issues occurred in the past month
Selected occupational health issues were divided into two categories namely, general occupational health issues and work-related musculoskeletal pain lasting more than a day (Table 3). The prevalence of headache (2.2%, 95% CI 1.5–3.1) and eye problems (2.1%, 95% CI 1.4–2.9) were the most common general health issues detected. Skin burns were the third highest general health issue reported by participants (0.88%, 95% CI 0.48–1.5). The rest of the general occupational health issues were below 0.5%. Back pain was the most prevalent work-related musculoskeletal pain reported by the participants (4.8%, 95% CI 3.8–6.1). Knee pain was the second highest with a prevalence of 4.4% (95% CI 3.4–5.6). Shoulder pain had a prevalence of about 3.3% (95% CI 2.5–4.4). Neck pain and wrist pain had a prevalence of about 3% each.
Most of the work-related musculoskeletal pain was either of short duration (lasting 1–6 days) or long lasting (more than 2 weeks) (Table 3). The pain lasting up to and no more than two weeks was generally less prevalent in all work-related musculoskeletal pain. About 60% of the knee pains and wrist pains reported by participants were lasting more than two weeks.
Discussion
Our study found that headaches and eye problems are the most common general occupational health issues reported in small-scale industries in the two districts. All other selected general occupational health issues were found to be less than one percent. This study also found back pain and knee pain among the most common work-related musculoskeletal pain reported by the participants. Furthermore, the majority of the work-related musculoskeletal pain was found to last a few days or more than 2 weeks.
One of the main strengths of this study was that it was conducted in two districts that represent the major demographic and socio-economic profile of the whole country. The sampling frame of this study was based on census data which increases the generalizability of the findings. The response rate of our study was over 90%. However, one of the important weaknesses of our study was that it only included four industry categories out of 27 industry categories in Sri Lanka. Another limitation of the study was that data was not collected by medical personnel so it may have introduced a non-differential misclassification bias irrespective of the meticulous attempts to train the data collectors [11]. The data collectors of this study collected data only during the daytime which may have resulted in an under representation of night shift workers in small-scale industries.
The results of our study can be compared with the population data to evaluate for the healthy worker effect with relation to lifestyle risk factors [12]. About 28.4% of the workers in our study were smokers and 14% were current regular smokers. Similarly, our study found 22.6% of the workers consumed alcohol (irrespective of type and amount) and nearly 41% of them reported daily alcohol consumption. In Sri Lanka, among the general adult population, the estimated prevalence of total current smokers was about 15% out of which 11.4% were daily tobaccosmokers [13]. This was much lower than the estimated prevalence in our study. The prevalence of alcohol use in the general population was higher than our study with consumption in the general population estimated to be around 65% [14].
According to the World Health Organization, in most countries respiratory diseases and musculoskeletal disorders are considered to be the leading occupational diseases [15]. Our study also found musculoskeletal disorders as the most prevalent occupational health issue among small-scale industry workers in Sri Lanka. This finding can be compared with other developing countries in the region. A study done in India among workers engaged in the small-scale garment industry also found musculoskeletal problems as the most common occupational health issue (69.94%) in their study. They further reported the most common body areas that are affected as neck (64.10%), low back (41.03%), hand, wrist, finger and shoulder [6]. One important difference between the two studies was that our study included four industry types while the Indian study only included the garment industry. A similar study in Nepal conducted among small-scale and household industry workers reports overall 33.3% musculoskeletal disorders [16]. Although this study includes main industry types such as metal, construction, garment and three other types of industries, most of the workers were of a younger age group (<20 years) than the current study. In addition, in these two studies, the majority of the workers were less educated and earned poor monthly income compared to the currentstudy.
With regards to the characteristics of occupation, the majority of the workers in our study had an experience of less than one year compared to 2 studies above where they reported most of the workers having more than 5 years of working experience. It has been found that workers having less experience are at a higher risk of musculoskeletal disorders in small-scale industries [17]. Similar to other regional studies [6, 17], findings of the current study also highlighted the majority of the workers worked in excess of 8 hours per day. Working long hours is identified as an important factor resulting in an increased likelihood of occupational injuries and illnesses [18].
In contrast to other studies about small-scale industries which report low supervision (less than 50%) at workplace settings [6, 19], nearly 91% workers in our study reported there was supervision available at their workplace. This is a significant finding in our study since competent supervision is considered as a protective factor in preventing injuries and illnesses in workplaces [18]. However, the effectiveness of the worker supervision in the current study is questionable since most of the workers reported that they were not following safety practices at workplaces.
The majority of the musculoskeletal pain in our study was either lasting a few days or of longer duration. Nearly 50% of the total musculoskeletal pain reported was lasting more than 2 weeks. This finding was in agreement with findings of other studies of small-scale industries which report prevalence of specific chronic musculoskeletal pain in a similarrange [17, 20].
Conclusions and recommendations
In conclusion, this study found work-related musc-uloskeletal pain in small-scale industries in Sri Lanka much more common than the work-related general health issues. Overall, the majority of the reported musculoskeletal pain was chronic duration in nature. Lack of experience and working long hours may have contributed to an increase in work-related musculoskeletal pain in this sector. Health promotional programs at workplaces focusing on ergonomics will benefit the workers at small-scale industries in Sri Lanka.
Conflict of interest
The authors declare no competing interests.
Authors’ contributions
IKS participated in study design, methodology, funding arrangements, statistical analysis and interpretation of results. SDW participated in statistical analysis, data collection, interpretation of results, and drafted the manuscript. SJS participated in data collection and statistical analysis. HDBH and TBAJ participated in study design and funding arrangements. All authors read and approved the final manuscript.
Funding
This work was supported by WHO / Sri Lanka.
Footnotes
Acknowledgments
We wish to thank all the data collectors and small scale industry officials in Gampaha and Kalutara district. We are extremely grateful to the workers in the two districts who have contributed to this study.