Discussion:
This study revealed that 74.1% of the quarry workers had poor quality of life. This finding could entail being dissatisfied with their work and working condition which directly affects the morale of the workers [29]. The quality of life of the workers is a vital element in the organizational management and plays key role in the growth and continued productivity of the organization. Therefore, deliberate efforts must be put in place to improve and maintain satisfied quality of work life among the workers as to ensure commitment and motivation on the part of the workers [6]. The condition of work, policy on welfare of the workers and every other organizational factor capable of impacting on the workers wellbeing should be addressed among the quarry industries in a timely manner [30]. One of such key approaches includes adequate social support, proper working conditions, good remuneration and psychological supports [31]. Low quality of life was also indicated in other studies conducted among different group of workers [26,32,33,31].
The result was contrary to the study done on accredited social health activist in Malaysia which revealed that 60% of the participants reported good quality of life [3]. This difference may be attributed to condition of work at the various industries, technological involvement, level of risk, health status of the workers, socio-cultural context [35] and the availability of psychosocial supports across countries [32]. Also, the relevance of the needs of the individual workers have been reported to vary across culture and organizations hence may account for the differences above [36].
Regarding the domains of the quality of life, the physical and environmental domain had the highest scores which however remained low on the 100% scale. These low scores may be accounted for by the poor working conditions and health status [32].
More also, at univariant analysis using simple logistic regression, certain independent variables showed significant association with quality of life. The factors include age, type of work, monthly income, level of pain, working with injury and work design. This is in agreement with reports of other research studies [35,32,37,38, 39 10].
Moreover, the multivariable analysis of the independent variables showed that two key independent variables, WRMSDs and poor work design remained significantly associated with quality of life of the respondents. WRMSDs is significantly associated with quality of life of the quarry workers in this study with unadjusted odd (4.28) when those without WRMSDs was used as reference. This therefore means that workers with WRMSDS have high odd (4.28) of being dissatisfied with their quality of life compared to those without WRMSDs. A few studies had reported a link between poor quality of life with job dissatisfaction, safety at work and low morale [11,40]. Therefore, appropriate preventive measures against WRMSDs is implicated by this finding as to improve the quality of life of the workers as well their commitment to organizational goal since evidence shows negative effects on poor quality of life on productivity at work [36]. This finding is in line with a study among primary healthcare workers which reported a significant association between health status and quality of life [33]. A similar finding was also indicated in a study among industrial dwellers in Poland in which their health status had significant association with their quality of life [32] and a study among physical therapist in Korea [41].
Poor work design also had remained significantly associated with the quality of life of the workers. This implies that workers working in poorly designed work environment were 3 times more likely to have poor quality of life than those who work in well-designed workplace. Therefore, the ergonomic design of the working units in the quarry industries in Nigeria is a predictor of the highly dissatisfied quality of life among the quarry workers. Previous study has reported the reiteration among construction company workers of the need for improved working environment for efficiency and improved health at work [42]. This study further confirms this reiteration. Similar study in Malaysia showed that 80% of the respondents found their work environment and work design as safe and adequate which is not comparable to the poor workplace design reported in this study [8]. International Labour Organization supported these findings that ergonomic principles of automation, substitution, and enclosure must be implemented in addition to ergonomic postural training of the workers to ensure safety at work [38].
Study conducted in Taiwan reported that workplace design and other environmental factors are sources of psychological threat and burnout among workers; burnout has in turn been a significant predictor of poor quality of life among workers [43]. This agrees with the result of the present study among the quarry workers in Nigeria. These predictors of quality of life need to be considered in developing interventional programs to address the welfare of the quarry workers in Nigeria as research evidence has attributed human performance at work to workplace factors experienced by the workers [44].