Experimental basis for the evaluation of effects of whole-body vibration in x- and y-directions on health and well beeing
Background: The evaluation methods described in ISO 2631-1 have been critically discussed within the EU member states, especially since the Directive 2002/44/EC (Vibrations) has been implemented. Compliance with the exposure limits has proven to be problematic, particularly regarding horizontal vibrations. However, these vibrations are relevant in many cases in practice. In comparison with vertical vibrations, they are often predominant (for tractors, agricultural machines, wheel loaders, etc.). There are no mandatory exposure limits for horizontal vibrations other than those in the EU Directive. The application of different factors (1.4 for the criteria 'health' and 1.0 for the criteria 'comfort') is a controversial point in the discussions on national and international scales.
Method: Subjects will be exposed to horizontal whole-body vibrations (x- or y- or combined xy-directions) in laboratory experiments. The effects will be measured as biodynamic parameters and subjective judgements (using psychophysical methods). The current frequency weighting curves and multiplying factors (ISO 2631-1) will be examined and, where required, modified so that the measured weighted exposure variables will adequately reflect the effects. The potential magnitude dependence of the frequency weightings will be investigated. Additionally, the extent of the dependence of the shape of the frequency curves on the type of vibration signal (e.g. sinusoidal signal, narrow-band or broad-band frequency spectra) will be examined.
Aim: The study aims at providing a scientific basis for the evaluation of risks due to whole-body vibrations. The current evaluation methods will be verified and improved where necessary.
Unit 3.1 "Prevention of Work-related Diseases"