Indicador ergonômico em operações de colheita florestal semimecanizada

Abstract

Despite the mechanized harvesting of wood being a strategy adopted by several large forestry enterprises, small forestry projects and the high initial investment can make the use of modern machines and equipment unfeasible, advocating manual and semi-mechanized work. However, the lowest degree of mechanization can cause some harm to the comfort and health of forest workers, as it requires a lot of physical effort, exposes them to high risk of accidents, environmental variables can exceed the recommended tolerance limits and, consequently, can expose these workers to inadequate working conditions within the ergonomic aspects. Given the above, this research aimed to analyze the ergonomic aspects of semi-mechanized wood harvesting, comparing the variables in an integrated way and classifying them according to the urgency of intervention. The study was carried out in areas of forestry promotion with Eucalyptus spp, implanted in sloping relief, submitted to clear cutting at the age of eight, located in the south of the state of Espírito Santo, Brazil. The activities of cutting with chainsaw, extraction by manual tipping and manual stacking on the sides of the roads were evaluated. The ergonomic analysis was carried out by characterizing the workers' profile through interviews and, for each activity, the physical load and the workers' exposure levels to hand and arm vibration, heat, noise and illuminance were determined. Data collection on environmental variables was performed by installing equipment on workers, as established in Brazilian occupational health and safety standards, as well as using specific methods cited in the literature. The classification of ergonomic variables was performed according to the degree of conformity method and the color scale was used to facilitate the visualization of the results. The results characterized the profile of forest workers involved in wood harvesting activities as young people, with high school education and an average experience of four years in the role, trained by the most experienced workers, where ergonomic practices are not adopted before or during the execution. of work, pointing out the need for immediate ergonomic interventions. Forestry cutting activities were the only ones with a physical workload within the recommended limits with a Cardiovascular Load of 40% and 34% respectively, in addition, chainsaw operators were exposed to hand and arm vibration and noise at levels above the tolerance limit. On the other hand, exposure to heat and illuminance showed acceptable levels, according to limits presented by regulatory standards. The use of the ergonomic indicators methodology made it possible to identify the ergonomic variables with the greatest potential for harm to workers' health and the most demanding activities in the execution of semi-mechanized wood harvesting operations. The results of the classification of intervention urgency showed that the exposure to noise from forest cutting for the chainsaw operator was the priority variable in a corrective ergonomic intervention, with a level of 97.1 and 100.6 dB(A) for felling and tracing/delimbing respectively.