Ergonomics and work safety

Operator Exposure to Noise and Whole-Body Vibration in a Fully Mechanised CTL Forest Harvesting System in Karst Terrain

volume: 40, issue: 1

In recent decades fully mechanised cut-to-length forest harvesting systems have spread from
flat and gentle to steep and rough terrain. To analyse the potential adverse impact of these
changes on operator health, an observational study of exposure to noise and whole-body vibration
(WBV) was carried out in karst terrain. The results showed that, in contrast to exposure
to noise, the exposure of harvester and forwarder operators to WBV exceeds the daily exposure
action value specified in the European Directive. Differences between work sites may contribute
up to 8.7 dB(A) to noise exposure and up to 0.28 m/s2 and 6.0 m/s1.75 to WBV exposure
when working with forwarders and harvesters. Aside from technical upgrades of machines,
reduction of exposure to both WBV and noise, while simultaneously maintaining high productivity,
requires careful selection of work sites and adapted work organisation.

Addressing Occupational Ergonomics Issues in Indonesian Forestry: Laborers, Operators, or Equivalent Workers

volume: 40, issue:

This study addresses occupational ergonomics issues in Indonesian forestry (work conditions, workers' characteristics, occupational safety, occupational health, and job satisfaction) to acquire a comprehensive perspective in understanding the actual problems facing the operations. Direct observation, interview, questionnaires, and secondary data analyses were carried out to acquire all of the required information. A total of 191 frontline forestry workers (chainsaw operators, helpers, manual hauling workers, skidder/tractor operators, logging truck drivers, and nursery workers) participated in this study. The study shows that various techniques of forest operations (labor-intensive to semi-mechanized systems) have been applied in Indonesian plantation forests, both short and long-rotation, as well as in natural forest management. Most of the workers were non-permanent workers, who receive a low wage, work under a straight piecework system, have a high dependency on the forestry work to make a living, and exhibit poor comprehension of the concept of hazard control. The fatality rate was recorded as 1.3 deaths/106 m3 log, but this may be even higher as this rate only represents data taken from formal forestry workers. An intense physical dimension of fatigue occurs among workers involved in forest operations, with the highest prevalence of musculoskeletal disorders in the upper back, lower back, neck, shoulders, and arms. This study reveals eight variables that influenced job satisfaction, i.e., wage, type of contract, accessibility, health services, living facilities, work equipment, training, and social facilities.

Physical Strain, Exposure to Noise and Postural Assessment in Motor-Manual Felling of Willow Short Rotation Coppice: Results of a Preliminary Study

volume: 40, issue:

Biomass for energy production and other bioproducts may be procured from various sources including willow short-rotation coppice (WSRC). Management of WSRCs involves several operations, including harvesting, which accounts for the greatest cost share and, if conducted motor-manually, it can expose the workers to noise, uncomfortable work postures and high cardiovascular loads. In this study, we evaluated the productivity, physical strain, exposure to noise, and postural risk index of workers operating in motor-manual felling of WSRC using a set of automatic dataloggers. Productivity of felling operations was rated at 0.07 ha/h, which is in line with the results reported by other studies. Cardiovascular load was rated at cca. 35% of the HRR, indicating a medium to heavy work experienced by the feller, with a greater contribution of tasks involving movement. Exposure to noise (LEX,8h = 95.19) exceeded the limit value set by the European legislation (87 dBA) and it could increase as a function of the engine utilization rate, which was 68% in this study, advocating for mandatory wearing of protective equipment. Postural risk index was evaluated at 191.11% for the worker handling the brush cutter and at 192.02% for the manual assistant indicating rather reduced risks, but also the need to evaluate how the dynamic work of the upper limbs would affect the workers’ health. While this work stands for a preliminary case study, the procedures described may be successfully used to easily collect long-term data in such operations.

The Effect of New Silvicultural Trends on Mental Workload of Harvester Operators

volume: 41, issue:

Close-to-nature (CTN) forestry offers many advantages, but makes management more complex and generally results in lower harvesting productivity and higher harvesting cost. While the higher harvesting cost of CTN is widely acknowledged, few ever consider the potential impact on operator workload, as the harvesting task becomes more complex. This study aimed to determine the mental workload of harvester operators under two silvicultural regimes: »pure conifer« stand and »mixwood« stand. In total, 13 harvester operators with varying experience levels were monitored for work performance and mental workload when operating a harvester simulator in two virtual stands designed according to the above-mentioned silvicultural regimes. Mental workload was assessed using the NASA Task Load Index (NASA-TLX) interview method and heart rate variability measurements, during two 30-minute test sessions performed in the »pure conifer« and the »mixwood« stand, respectively. As expected, operating in a more diversified »mixwood« stand resulted in a marked productivity loss, estimated between 40 and 57%. The study also confirmed the increased aggravation of mental demand, effort and frustration experienced by the operators when passing from the »pure conifer« stand to the »mixwood« stand. Such increase in mental workload was independent of the age and experience of the operators. Results can be used to paint a more holistic picture of CTN forestry and its implications for harvester operators. Besides increasing the number of subjects being monitored, future studies should focus on live forest operations.

Workability and Well-Being at Work Among Cut-To-Length Forest Machine Operators

volume: 42, issue:

This study assessed the situation of Finnish cut-to-length (CTL) machine operators’ work well-being with workability index (WAI), investigated CTL machine operators’ lifestyle habits, and collected operators’ good practices to maintain and promote well-being and vitality at work. A questionnaire was conducted in electronic form, including questions concerning background information, work environment, work organisation, well-being at work and free time, and workability index. Mean WAI among respondents was 42.2 points (max. 49) falling into the rank »good«, while the current workability compared with the lifetime best was 8.2 (range 0–10). WAI was strongly impacted by age (p<0.000), the score declined during ageing, and standard deviation grew. The results were in line with previous WAI studies. Statistic differences were found between youngest age group (age≤25) versus all others. Compared to other studies and occupational groups, CTL machine operators’ WAI was average. Operators revered independent nature of work and forest as a working environment, thus promoting and maintaining well-being at work. Furthermore, breaks during work shift, with or without physical exercise, was recognised to ensure and retain vitality and concentration at work.

Mental Workload, Occupational Fatigue and Musculoskeletal Disorders of Forestry Professionals: The Case of a Loblolly Plantation in Northern Iran

volume: 43, issue:

Musculoskeletal disorders (MSD) comprise one of the most important occupational health issues in forestry professions. The purpose of the study was to examine the association among musculoskeletal disorders, antrhopometric and personal data, mental workload and occupational fatigue in forest professionals in northern Iran by means of the Nordic Musculoskeletal Questionnaire (NMQ), the National Aeronautics and Space Administration Task Load Index (NASA-TLX), and the Swedish Occupational Fatigue Inventory (SOFI). More than eight out of every ten subjects reported at least one MSD symptom during the past 12 months, with lower back (72.5%), feet and ankles (49%) and neck (41.2%) being the more frequently affected body regions. Similar MSD prevalences were reported for the period of seven days prior to data collection. Both the mental workload (grand mean 73.18±7.54) and occupational fatigue (grand mean 106.20±24.53) achieved high scores. MSD prevalence was found to be correlated with the SOFI score and the NASA-TLX score during the last year and seven days prior to data collection, respectively.

Overall, the study results confirm the very demanding nature of the forest professions, which are characterized by high MSD prevalence, increased occupational fatigue and high mental workload. Given the small-scale forestry characteristics in the study area, taking measures such as introducing vocational training and promoting the use of personal protective equipment are some first necessary steps for the local forestry workforce.

Exposure to Occupational Noise: Machine Operators of Full Tree System in Brazil

volume: 43, issue:

Physical agent noise can be considered one of the main disturbances that compromise the occupational health of self-propelled forest machine operators. We evaluated whether occupational noise levels emitted by self-propelled forest machines employed in the full tree system are in accordance with both the National Institute for Occupational Safety and Health and ISO 1999:2013 standards, while also proposing mitigating measures aimed at protecting the operators hearing. Seventeen operators, who performed wood harvesting operations in Eucalyptus forests in Brazil, were analyzed. Noise levels were collected in a daily shift of eight hours as recommended by the Acoustics – Determination of occupational noise exposure - Engineering method for full-day measurements (ISO 9612:2009). The standards adopted for the evaluation were the exposure action value of 80 dBA and the exposure limit of 85 dBA based on the National Institute for Occupational Safety and Health – NIOSH and on Acoustics – Estimation of noise-induced hearing loss (ISO 1999:2013) Directive 2003/10/EC. The operators were arranged in homogeneous groups according to the Acoustics recommendation – Determination of occupational noise exposure - Engineering method for full-day measurements (ISO 9612:2009), classified by the operations of felling, skidding of tree bundles and bucking. The results showed that 17 self-propelled forest machines exceeded the exposure action value of 80 dBA, of which 10 machines exceeded the exposure limit of 85 dBA. It was concluded that the levels of occupational noise emitted by self-propelled forest machines used in the full tree system are higher than those recommended by both standards, National Institute for Occupational Safety and Health and ISO 1999:2013. Therefore, the allocation of self-propelled forest machines to homogeneous groups allows inferring mitigation actions that protect operators' hearing. The correct use of hearing protectors during the daily workday provides hearing protection for operators in mechanized wood harvesting. Adoption of actions such as maintenance of cabin seals and mechanical components, breaks for fatigue relief, reduction of daily working hours and rotation of operators in different self-propelled forest machines can mitigate the damage to the occupational health of operators.

Workability and Physical Wellbeing Among Chainsaw Operators in Croatia

volume: 44, issue:

Motor-manual felling and wood processing is a high-risk work process where the chainsaw, in connection to other variables in the working environment, is a key and constant source of risk and danger for forest chainsaw operators. Pursuant to the foregoing, the purpose of this research is to investigate and compare detected musculoskeletal disorder (MSD) symptoms among the chainsaw workers in Croatia according to their employer (state company – Hrvatske šume Ltd. or private forestry contractor) and self-evaluated Workability Index. A combined three-stage research method was used: (a) defining a sample; (b) preparation and administration of questionnaire; and (c) data analysis and elaboration. The Standardized Nordic Questionnaire (SNQ) was used as a medium to detect musculoskeletal disorder symptoms in chainsaw operators and the Workability Index (WAI) questionnaire was used as a medium for workability self-evaluation. The field part of face-to-face data collection was conducted in the first quarter of 2022 with a total of 158 sampled workers interviewed directly at the forest worksite. Descriptive and inferential statistical methods were used to verify and analyze the data. The anatomical area with the highest 12-month period prevalence of MSD symptoms for all chainsaw operators is the low back (70.89%), followed by the shoulders (41.14%), neck (39.87%) and wrist/hands (36.71%). Research results, according to the employer, showed that workers employed by Hrvatske šume Ltd. have a higher prevalence of MSD symptoms in almost all anatomical locations compared to chainsaw operators employed by private forest contractors. Mean WAI Score among all respondents was 34.96 points (max. 49) falling into the rank »moderate«, while the current workability compared with the lifetime best was 7.33 (range 0–10). The results of MSD symptoms confirm the self-estimated higher values related to health problems caused by forestry work and lower WAI Score by workers employed in the state forestry sector compared to workers employed in private forestry sector. The prevalence of MSD symptoms, observed through WAI Score, showed a significantly lower percentage of affirmative responses for all anatomical regions except for shoulders in workers who need to maintain their workability. The obtained results show positive correlation with descriptive indicators, where younger workers with less chainsaw work experience have a lower prevalence of MSD symptoms and better WAI Score. In the discussion and conclusion part of the research in question, the need for development of possible solutions is emphasized. The proposed solutions can be included into educational programs or on-site training related to the MSD risks for professional chainsaw workers to change their behaviour that will reduce occupational risks.


Web of Science Impact factor (2022): 3.200
Five-years impact factor: 3.000

Quartile: Q1 - Forestry

Subject area

Agricultural and Biological Sciences