engleski

Concentration of Wood Dust in the Working Environment during Felling and Processing of Beech Trees

This paper shows the results of measurement of daily exposure of five cutters to respirable particles, i.e. to total wood dust during felling and processing of beech trees. The research was carried out in a mixed stand (beech 56%, oak 28%, hornbeam 16%), 109-year old in the central mountainous region of the Republic of Croatia at an altitude ranging between 170 and 210 m. The operations of felling and processing were carried out by use of chain saw Stihl 044. For determining the mass concentration of wood dust by the method of personal collectors, the separators (cyclons) were used, which operate in a way that imitates the worker's respiratory system, i.e. the separation of non-respirable fraction and respirable particles with a medium efficiency (50%) with aerodynamic diameter of 5 μ m. During the research only beech trees were cut. The measurements were carried out of the factors affecting the dustiness of the cutter's working environment (tree diameter at breast height, temperature, pressure and relative air humidity, mean and maximal air flow rate). In the sample of 27 measurements, the mean value of mass concentration of total beech dust was 1.059 +/- 0.43 mg/m3, and of respirable fraction 0.52 +/- 0.43 mg/m3. Regulatory Acts are currently being prepared in Croatia, which classify beech dust as one of carcinogenic substances with the limit values of 1 mg/m3 for respirable fraction and 3 mg/m3 for total wood dust of hardwood species. The significance of the results of this research is that three out of fourteen measured values of mass concentration of respirable particles exceed the limit values of wood dust mass concentration of hardwood species in the cutter's working environment.

wood dust; mass concentration; beech; cutter; working environment

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