Miners’ return to work following injuries in coal mines

Background: The occupational injuries in mines are common and result in severe socio-economical consequences. Earlier studies have revealed the role of multiple factors such as demographic factors, behavioral factors, health-related factors, working environment, and working conditions for mine injuries. However, there is a dearth of information about the role of some of these factors in delayed return to work (RTW) following a miner’s injury. These factors may likely include personal characteristics of injured persons and his or her family, the injured person’s social and economic status, and job characteristics. This study was conducted to assess the role of some of these factors for the return to work following coal miners’ injuries. Material and Methods: A study was conducted for 109 injured workers from an underground coal mine in the years 2000–2009. A questionnaire, which was completed by the personnel interviews, included among others age, height, weight, seniority, alcohol consumption, sleeping duration, presence of diseases, job stress, job satisfaction, and injury type. The data was analyzed using the Kaplan-Meier estimates and the Cox proportional hazard model. Results: According to Kaplan-Meier estimate it was revealed that a lower number of dependents, longer sleep duration, no job stress, no disease, no alcohol addiction, and higher monthly income have a great impact on early return to work after injury. The Cox regression analysis revealed that the significant risk factors which influenced miners’ return to work included presence of disease, job satisfaction and injury type. Conclusions: The mine management should pay attention to significant risk factors for injuries in order to develop effective preventive measures. Med Pr 2016;67(6):729–74

Structural equation modelling of work related musculoskeletal disorders among dumper operators

Abstract The aim of this study is to investigate the impact of personal factors, habitual factors, and work-related factors on work-related musculoskeletal disorders (WRMSDs) among dumper operators. In total, 248 dumper operators working in an iron ore mine were considered for this study. A questionnaire was developed and administered to collect dumper operators' personal, habitual, and work-related data. The reliability of the questionnaire was cross-checked by Cronbach alpha and the test–retest method. The values of Cronbach alpha for all latent variables were above 0.7, and the correlation coefficient of the questionnaire items at Time 1 and Time 2 was above 0.82. After verifying the validity (i.e., convergent and divergent) of the questionnaire data, the relationship between the factors under consideration was examined by structural equation modeling (SEM). The SEM demonstrated a moderate fit, with \frac{{\upchi }^{2}}{df} χ 2 df value of 1.386, comparative fit index (CFI) of 0.86, goodness-of-fit index (GFI) of 0.72, adjusted goodness-of-fit index (AGFI) of 0.69, Tucker-Lewis Index (TLI) of 0.83, normed fit index (NFI) of 0.71 and root mean square error of approximation (RMSEA) of 0.051. The SEM analysis revealed a positive relationship between WRMSDs and personal factors (with path coefficient = 0.313 and p  0.05). Overall, this study provides valuable insights into the factors that influence the prevalence of WRMSDs among dumper operators. The findings highlight the significance of personal and work-related factors by which one can make a positive decision to prevent and reduce the incidence of WRMSDs among dumper operators

The role of occupational activities and work environment in occupational injury and interplay of personal factors in various age groups among Indian and French coalminers

Objective: The role of occupational hazards in occupational injury may be mediated by individual factors across various age groups. This study assessed the role of occupational hazards as well as contribution of individual factors to injuries among Indian and French coalminers. Material and Methods: We conducted a case-control study on 245 injured workers and on 330 controls without any injuries from Indian coal mines using face-to-face interviews, and a retrospective study on 516 French coalminers using a self-administered questionnaire including potential occupational and personal factors. Data were analyzed using logistic models. Results: The annual rate of injuries was 5.5% for Indian coalminers and 14.9% for the French ones. Logistic model including all occupational factors showed that major injury causes were: hand-tools, material handling, machines, and environment/work-geological/strata conditions among Indian miners (adjusted oddsratios 2.01 to 3.30) and biomechanical exposure score among French miners (adjusted odds-ratio 3.01 for score the 1-4, 3.47 for the score 5-7, and 7.26 for score ≥ 8, vs. score 0). Personal factors among Indian and French coalminers reduced/exacerbated the roles of various occupational hazards to a different extent depending on workers' age. Conclusion: We conclude that injury roles of occupational hazards were reduced or exacerbated by personal factors depending on workers' age in both populations. This knowledge is useful when designing prevention which should definitely consider workers' age