Development of an intervention program to reduce whole-body vibration exposure based on occupational and individual determinants among dumper operators

Objectives. Studies related to a systematic approach for intervention design to reduce whole-body vibration (WBV) exposure are scarce. This study presents a systematic approach to identifying, selecting and prioritizing safety interventions to fulfill that research gap. Methods. A total of 130 vibration readings for dumper operators were taken from two surface iron ore mines to identify significant determinants of WBV exposure. Initially, age, weight, seat design, awkward posture, machine's age, load tonnage, dumper speed and haul road condition were hypothesized as determinants. Data were collected through standardized questionnaires and field-based observation. A multivariate statistical approach was applied for the practical use of the intervention program. Results. As some of the hypothesized factors were correlated, exploratory factor analysis (EFA) followed by multiple linear regression (MLR) was used to investigate their association with WBV exposure. As per EFA results, hypothesized factors were clubbed under individual, ergonomics and occupational factors. Occupational and ergonomics factors were found to be significantly associated with WBV exposure through MLR and used to form safety interventions to reduce WBV exposure. Conclusions. Our methodological approach is original in the occupational health research area and can be helpful to tailor the safety interventions for the unit level with minimum effort.

Reducing musculoskeletal disorders in iron ore mine operators: A fuzzy-based intervention approach

BACKGROUND

This study focuses on evaluating the exposure to whole-body vibration (WBV) and association of musculoskeletal disorders (MSDs) with various risk factors among dumper operators in the mining industry. Despite the issue's significance, prior research has been limited.

OBJECTIVE

The study introduces a novel fuzzy-based approach for identifying, selecting, and prioritizing safety measures to mitigate MSD risks.

METHODS

Data collection comprised face-to-face interviews, anthropometric measurements, Rapid Upper Limb Assessment (RULA) scoring for posture assessment, and the Nordic Musculoskeletal questionnaire for assessment of MSD prevalence. Multiple linear and logistic regression models were used to analyse the contributing risk factors to MSDs and WBV exposure. These risk factors formed the basis for a practical approach to select appropriate safety measures based on fuzzy based aggregation method of expert's judgment aimed at mitigating the risk of MSDs.

RESULTS

The results revealed that the risk factors such as poor work posture, WBV exposure and poor seat design were significantly associated with neck (adjusted odds ratio aOR = 4.81), upper limb and shoulder (aOR = 3.28), upper back (aOR = 5.09), and lower back pain (aOR = 3.67) at p < 0.05. Using these factors to formulate safety measures to reduce MSD risk, the minimization of sharp turns and abrupt changes in elevation in designing the haul roads, scheduled maintenance practices, and ergonomic seat design were found as important safety measures in this study.

CONCLUSION

Our unique methodological approach in occupational health research could be highly beneficial for tailoring safety measures at the unit level with minimal effort.

A practical framework to develop and prioritize safety interventions to improve underground coal miners' safety performance

BACKGROUND

Improvement of workers' safety performance is an integral and essential part of safety management. Relevant safety interventions to improve workers' safety performance are generally difficult to establish when there is a wide range of occupational hazards and at-risk individuals' features.

OBJECTIVE

This study aimed at formulating a practical approach to develop and prioritize potential safety interventions based on occupational and individual risk factors perceived by workers to promote workers' safety performance.

METHODS

A simple framework developed to identify and prioritize the suitable safety interventions. This framework made use of data collected using standardized and validated questionnaire and domain experts' opinions. Pearson correlation coefficients, exploratory factor analysis, and multiple linear regression were used to identify significant risk factors associated with workers' safety performance. Data were collected by interviewing 202 coal mine workers with occupational injuries, and their immediate supervisors from three mines.

RESULTS

Safety performance was associated with the occupational factor-domain (poor working condition, poor safety environment, poor job satisfaction, and high job stress) only (regression coefficient = 2.14, p < 0.01). The following interventions were identified and prioritized to promote workers' safety performance: provide fair compensation to workers, job-specific and safety training, promotion policy, achievable targets, relevant perks/benefits, safety training awareness, workplace lighting, ventilation network, sensitize the management, associate safety performance to promotion, and develop team spirit.

CONCLUSION

Our approach helps to identify and prioritize the most relevant interventions to promote safety at work when there are multiple risk factors.

Associations between School-Behavior-Health Difficulties and Subsequent Injuries among Younger Adolescents: A Population-based Study

Objective: School-behavior-health difficulties (SBHDs) may alter physical/mental capabilities and consequently increase injury risk during daily activities. This study assessed the associations of potential SBHDs and their cumulative number (SBHDcn) with various injury types among younger adolescents. Methods: The study population included 1,559 middle-school adolescents in France (10-18 years, 98% under 16,778 boys and 781 girls). They completed a questionnaire at school-year end collecting socioeconomic features (nationality, family structure, parents' education/occupation/income), school/out-of-school injuries during the school-year (dependent variables), and SBHDs starting before the school-year (low academic performance, alcohol/tobacco/cannabis/other-illicit-drugs use, physical/verbal violence, sexual abuse, perpetrated violence, poor social support, poor general health status, sleep difficulty, depressive symptoms, and suicide attempt). Data were analyzed using logistic regression models and Kaplan-Meier estimates. Results: Injuries were frequent during school-physical/sports-training (10.9%), other-school-training (4.7%), school-free-time (7.4%), out-of-school-sports-activity (16.5%), and traffic (2.2%). Single injury (one injury all injury types combined) and ≥2 injury types affected 23.3 and 7.9% of subjects, respectively. The proportion of adolescents without SBHDs decreased with age more quickly among those with each injury type than among those without injury. Various SBHDs were associated with most injury types, single injury, and ≥2 injury types (sex-age-adjusted odds/relative-risk ratios reaching 11, p < .001). A dose-effect association was found between SBHDcn 1-2/3-5/≥6 and both single injury and ≥2 injury types (sex-age adjusted relative risk ratios reaching 12.66, p < .001, vs. SBHDcn = 0). Socioeconomic features had a moderate confounding role in these associations. Conclusions: SBHDs strongly predict injuries among adolescents. Our findings may inform healthcare providers about their prominent role in detecting/reducing SBHDs and injuries.

Association between screen time and cumulating school, behavior, and mental health difficulties in early adolescents: A population-based study

Early adolescents may daily spend excessive screen-time (with television viewing, computer/console gaming, discussion forums/chatting online, internet surfing, doing homework, and electronic mails) while its association with cumulating several school-behavior-mental-health difficulties (SBMDs) (poor-academic-performance, being obese, alcohol/tobacco/cannabis/other-illicit-drugs use, suffered violence, sexual abuse, perpetrated violence, poor social support, depressive symptoms, and suicide attempt) is poorly addressed. We investigated this association among 1559 middle-school adolescents from north-eastern France (mean age 13.5 ± 1.3). They completed a questionnaire including socioeconomic features, daily screen-time for various screen-based activities (coded 1=<2/2=2-4/3=≥5 h; daily-total-screen-time level DSA_total was defined as their sum and categorized into 4 levels: 6-7/8-9/10-12/≥13), various SBMDs and the time of their onset during the life course (their cumulated number SBMD_score was categorized into 5 levels: 0/1/2/3-4/≥5). Logistic regression modeling showed that the DSA_total was strongly associated with all SBMDs (gender-age-adjusted odds ratio reaching 8.28, p < 0.001) and SBMD_score (gender-age-adjusted relative risk reaching 11.60, p < 0.001, pseudo R² = 0.039). These associations remained strongly significant when controlling for socioeconomic adversities (contributions 20-38%). The proportion of subjects without each SBMD steadily decreased with age according to DSA_total levels. These findings help to understand the impacts of high DSA_total on SBMDs in early adolescents and identify at-risk adolescents for prevention and care.

Association between Whole-Body Vibration exposure and musculoskeletal disorders among dumper operators: A case-control study in Indian iron ore mines

BACKGROUND

Dumper operators in mines worldwide are subjected to Musculoskeletal Disorders (MSDs) due to whole-body vibration exposure. This study evaluated the working-life-Whole-Body Vibration (WBV)-exposure and their association with various MSDs among dumper operators in mines which remains poorly addressed.

METHODS

This case-control study in Indian iron ore mines was conducted to compare randomly selected 65 dumper operators and 65 office workers. Data were collected through face-to-face interviews using the Nordic Musculoskeletal Questionnaire (NMQ) and were analysed using logistic regression models.

RESULTS

The study revealed that majority of the dumper operators were exposed to WBV exceeding the ISO-2631 limits. Compared with controls, the dumper operators had a much higher risk of upper back pain (age-overweight-adjusted odds ratio ORao = 5.37, 95%CI = 1.78-16.20), lower back pain (ORao = 2.72, 95%CI = 1.25-5.94), knee and leg pain (ORao = 3.68, 95%CI = 1.22-11.11), and having 2+ MSDs (ORao = 5.05, 95%CI = 1.88-13.51, vs. no MSDs). Working-life-WBV-exposure was higher among dumper operators having upper back pain (mean (SD) = 7.1 (1.91) vs. 5.7 (1.91), p <  0.01) and lower back pain (mean (SD) = 6.63 (2.10) vs. 5.55 (1.71), p <  0.01) compared to those without these MSDs. Older age was associated with higher risk of MSD pains.

CONCLUSION

Dumper operators have excess MSDs due to high working-life-WBV-exposure. Their MSDs and working-life-WBV-exposure should be regularly evaluated and reduced.

Role of whole-body vibration exposure and posture of dumper operators in musculoskeletal disorders: a case study in metalliferous mines

Objectives. The combined role of whole-body vibration (WBV) exposure and awkward posture on musculoskeletal disorders (MSDs) experienced by dumper operators in two metalliferous mines in India was evaluated through a cross-sectional study. Methods. Frequency-weighted root mean square (rms) acceleration was used for WBV exposure assessment. Anthropometry and rapid upper limb assessment (RULA) were used for static and dynamic posture assessment, respectively. Prevalence of MSDs was assessed using the Nordic musculoskeletal questionnaire (NMQ). Logistic regression was used to assess the factors contributing to MSD problems. Results. The rms values revealed that the operators exceeded the lower limit of Standard No. ISO 2631-1:1997. The dynamic posture study revealed that the majority of dumper operators were taking awkward postures and 58-74% of them were subjected to high and medium levels of MSD risk. The adjusted odds ratio (7.96, 95% confidence interval [1.24, 41.35]) for the most awkward postures revealed WBV exposure as the significant risk factor for MSD problems among the operators. Conclusion. WBV exposure and posture of operators should be regularly monitored and corrective actions implemented to reduce their MSD problems. Ergonomic seat design based on the anthropometry of the operators should be assessed at the time of procuring new equipment.

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):729-742.

Whole-body Vibration Exposure of Drill Operators in Iron Ore Mines and Role of Machine-Related, Individual, and Rock-Related Factors

Background

This study aimed to assess the whole-body vibration (WBV) exposure among large blast hole drill machine operators with regard to the International Organization for Standardization (ISO) recommended threshold values and its association with machine- and rock-related factors and workers' individual characteristics.

Methods

The study population included 28 drill machine operators who had worked in four opencast iron ore mines in eastern India. The study protocol comprised the following: measurements of WBV exposure [frequency weighted root mean square (RMS) acceleration (m/s²)], machine-related data (manufacturer of machine, age of machine, seat height, thickness, and rest height) collected from mine management offices, measurements of rock hardness, uniaxial compressive strength and density, and workers' characteristics via face-to-face interviews.

Results

More than 90% of the operators were exposed to a higher level WBV than the ISO upper limit and only 3.6% between the lower and upper limits, mainly in the vertical axis. Bivariate correlations revealed that potential predictors of total WBV exposure were: machine manufacturer (r = 0.453, p = 0.015), age of drill (r = 0.533, p = 0.003), and hardness of rock (r = 0.561, p = 0.002). The stepwise multiple regression model revealed that the potential predictors are age of operator (regression coefficient β = −0.052, standard error SE = 0.023), manufacturer (β = 1.093, SE = 0.227), rock hardness (β = 0.045, SE = 0.018), uniaxial compressive strength (β = 0.027, SE = 0.009), and density (β = –1.135, SE = 0.235).

Conclusion

Prevention should include using appropriate machines to handle rock hardness, rock uniaxial compressive strength and density, and seat improvement using ergonomic approaches such as including a suspension system.

Synthesis of Nano-Crystalline Materials in Open-Air Laboratory: A Case Study of Tobacco

The work deals with synthesis of nano-crystalline materials in open-air laboratory and in-depth investigation of the tobacco sample of one branded cigarette and its ash using high-resolution transmission electron microscopy and associated techniques. It exhibits the presence of nanocrystals and nanorods of various oxides in cigarette ash. The structure, shape, size and composition of these nanocrystals and nanorods are explored. The energy dispersive X-ray spectra from different regions of the tobacco sample and its ash using high-angle annular dark field scanning/transmission electron microscopy mode are utilized to obtain elemental composition and their relative abundances. For a detailed distribution of different elements in the nanorods, elemental mapping using energy-filtered transmission electron microscopy is also presented. The results highlight the conversion of amorphous constituents of tobacco to nanomaterials on combustion at low temperatures, thus mixing up in the atmosphere.

Relationship between job, lifestyle, age and occupational injuries

BACKGROUND

Physical job demands (PJD), age, disability and lifestyle may influence the risk of occupational injury.

AIM

To assess the relationships between PJD, lifestyle and injury in workers of various ages.

METHODS

A total of 2888 randomly selected workers from northeastern France, aged >or=15, completed a postal questionnaire. The PJD score was defined as the total number of the following reported job demands: using pneumatic tools, other vibrating hand tools, hammers, machine tools or vibrating platforms and exposure to manual handling tasks, awkward postures, high pace of work, high physical workload, work at heights, work in adverse climates or exposure to noise, cold or heat. Data were analysed using logistic regression.

RESULTS

Nine per cent of subjects reported an injury during the previous 2 years. The PJD score was related to the injury rate for workers aged >or=45: crude odds ratio (OR) 3.5 (95% confidence interval = 1.5-8.0) for PJD = 1, 5.0 (2.2-11.3) for PJD = 2-3 and 14.5 (6.5-32.2) for PJD >or=4, versus PJD = 0. Lower ORs were found for those aged <30 (1.4, 4.2 and 9.9, respectively) and 30-44 (1.5, 4.4 and 6.5, respectively). The differences between age groups remained when controlling for all factors studied. Obesity, smoking and musculoskeletal disorders were associated with injury risk in workers aged >or=45 (adjusted ORs 1.7-2.6). Smoking was also an injury risk factor for workers aged <30.

CONCLUSIONS

PJD and lifestyle have a higher impact on injury rates among older workers than among younger ones. Injury prevention should address reducing PJD and improving relevant lifestyle factors, especially for older workers.

Relationships of job hazards, lack of knowledge, alcohol use, health status and risk taking behavior to work injury of coal miners: a case-control study in India

Objective is to assess the relationships of job hazards, individual characteristics, and risk taking behavior to occupational injuries of coal miners. This case-control study compared 245 male underground coal miners with injury during the previous two-year period with 330 matched controls without injury during the previous five years. Data were collected via face-to-face interview and analyzed using the conditional logistic model. Handling material, poor environmental/working conditions, and geological/strata control- related hazards were the main risk factors: adjusted ORs 5.15 (95% CI 2.42-10.9), 2.40 (95% CI 1.29-4.47), and 2.25 (95% CI 1.24-4.07) respectively. Their roles were higher among the face-workers than among the non-face-workers. No formal education, alcohol consumption, disease, big-family, and risk-taking behavior were associated with injuries (2.36</=ORs</=10.35), and the findings were similar for both face and non-face workers. Prevention should focus on handling material, poor environmental condition, especially addressing workers with no formal education, alcohol consumption, disease, big family size, and risk-taking behavior.

Associations of job, living conditions and lifestyle with occupational injury in working population: a population-based study

OBJECTIVES

To assess the roles of job demands, living conditions and lifestyle in occupational injury.

METHODS

The sample included 2,888 workers, aged > or =15 years, randomly selected from the north-eastern France. The subjects completed a mailed questionnaire. Data were analyzed with adjusted odds ratios (ORa) computed with the logistic model.

RESULTS

In total, 9.2% of workers had an injury during the previous 2 years. The high job demands: tasks at height, handling objects, pneumatic tools, other vibrating hand tools, work in adverse climate, physical workload, vibrating platform, machine tools, cold, heat, awkward posture, noise, hammer, and pace had crude odds ratios between 1.81 and 5.25 for injury. A strong exposure-response relationship was found between the cumulated job demands (CJD, defined by their number) and injury: OR 1.88 (95% CI 1.23-2.87) for CJD1, 4.39 (2.98-4.46) for CJD2-3, and 9.93 (6.70-14.7) for CJD > or = 4, versus CJD0. These ORs decreased to 1.68, 3.70, and 7.15 respectively, when adjusted for sex, age, and living conditions/lifestyle confounders; and to 1.54, 2.99, and 5.45 respectively when also adjusted for job category. The following factors had significant ORa: age <30 years (1.54, 1.12-2.12), male (1.64, 1.18-2.30), smoking (1.60, 1.22-2.10), musculoskeletal disorders (1.54, 1.17-2.04), and frequent drug use for fatigue (2.03, 1.17-3.53). The workmen, farmers/craftsmen/tradesmen, and foremen had a 5.7-8.7-fold while the clerks and technicians a 2.7-3.6-fold higher risk compared with upper class. The risk associated with CJD was twofold higher among the workers aged > or =40 or with frequent drug use for fatigue compared with the others. Obesity had ORa 2.05 (1.11-3.78) among the subjects aged > or =40, and excess alcohol use had ORa 2.44 (1.26-4.72) among those free of disease.

CONCLUSIONS

This study identified a wide range of job demands and living conditions/lifestyle which predicted injury. Preventive measures should be conducted to reduce job demands and to help workers to be aware of the risk and to improve their living conditions/lifestyle.

Relationships of physical job tasks and living conditions with occupational injuries in coal miners

This study assessed the relationships of job tasks and living conditions with occupational injuries among coal miners. The sample included randomly selected 516 underground workers. They completed a standardized self-administred questionnaire. The data were analyzed via logistic regression method. The rate of injuries in the past two years was 29.8%. The job tasks with significant crude relative risks were: power hammer, vibrating hand tools, pneumatic tools, bent trunk, awkward work posture, heat, standing about and walking, job tasks for trunk and upper/lower limbs, pain caused by work, and muscular tiredness. Logistic model shows a strong relationship between the number of job tasks (JT) and injuries (adjusted ORs vs. JT 0-1: 2.21, 95%CI 1.27-3.86 for JT 2-6 and 3.82, 2.14-6.82 for JT>or=7), and significant ORs>or=1.71 for face work, not-good-health-status, and psychotropic drug use. Musculoskeletal disorders and certain personality traits were also significant in univariate analysis. Therefore job tasks and living conditions strongly increase the injuries, and occupational physicians could help workers to find remedial measures.

Relationships of working conditions and individual characteristics to occupational injuries: a case-control study in coal miners

This study assessed the relationship of age, poor perception of working condition, poor safety environment, poor management and supervision, risk-taking behavior, emotional instability, negative job involvement, job dissatisfaction, job stress, and poor safety performance of workers to occupational injuries. This case-control study was conducted on 202 male coal miners with at least one occupational injury during a five-year period and 202 male controls with no occupational injury, matched on the job. A standardized questionnaire administered by individual interviewers was used. Data were analysed by the logistic regression method. For all workers combined, the factors with significant adjusted odds ratios (ORs) found were: 30-45 and >45 yr age groups (OR vs. <30 yr age group: 1.80, 95% CI 1.02-3.17 and 2.59, 1.38-4.85 respectively), poor perception of working conditions (1.61, CI 1.00-3.18), emotional instability (2.33, 1.04-5.22), job stress (1.83, 1.00-3.46) and poor safety performance of workers (3.10, 1.45-6.63). No significant interaction was found between these risk factors and the job. It was concluded that older age, poor perception of work conditions, poor work environment, and human behavioral factors played significant roles in occupational injuries. This information would help in implementing preventive programs to improve working conditions and management quality and to help the workers to develop positive psychological traits, but workers with negative traits such as emotional instability and older workers should be employed in less demanding jobs.

Relationships of job and some individual characteristics to occupational injuries in employed people: a community-based study

This study assessed the associations of job and some individual factors with occupational injuries among employed people from a general population in north-eastern France; 2,562 workers were randomly selected from the working population. A mailed auto-questionnaire was filled in by each subject. Statistical analysis was performed with loglinear models. The annual incidence rate of at least one occupational injury was 4.45%. Significant contributing factors for occupational injuries were job category (60.8%), sex (16.2%), regular psychotropic drug use (8.5%), age groups (7.5%), and presence of a disease (7.0%). The men had higher risk than the women (adjusted odds-ratio 1.99, 95% CI 1.43-2.78). Compared to executives, intellectual professionals and teachers, labourers had the highest risk (6.40, 3.55-11.52). They were followed by farmers, craftsmen and tradesmen (6.18, 2.86-13.08), technicians (3.14, 1.41-6.70), employees (2.94, 1.59-5.48) and other subjects (3.87, 1.90-7.88). The young (< or = 29 yr) showed an increased risk. Similar odds-ratios were observed for regular psychotropic drug use (1.54, 1.16-2.05) and the presence of a disease (1.50, 1.11-2.02). Univariate analysis showed that smoking habit, overweight and excess alcohol use were also associated with injuries. The loglinear model results showed that there were associations between some of these independent factors. It was concluded that job, sex, young age, smoking habit, excess alcohol use, overweight, psychotropic drug use, and disease influenced the occupational injuries. Preventive measures concerning work conditions, risk assessment and job knowledge should be conducted in overall active population, especially in men, young workers, smokers, alcohol users, overweight workers and in individuals with a disease or psychosomatic disorders.