Hazards due to special physical action

Forms of special physical action in the meaning of the present guide encompass noise, vibrations, optical and ionising radiation, electromagnetic fields and vacuum and gauge pressure.

Noise designates any sound which can lead to hearing damage or to extra-aural hazards, such as failing to hear warning signals, impaired well-being and communication, an increased risk to the cardiovascular system and reduced performance on the part of workers.

Vibrations, in others words mechanical oscillations, which are transferred from objects to the human body, encompass whole-body vibrations which cause in particular back pains and spinal damage, and hand-arm vibrations which can lead to bone or joint damage, impaired blood supply or neurological disorders.

At workplaces there may also arise – even unintentionally – the action of ionising or non-ionising radiation on workers.
Ionising radiation includes radiation whose energy is sufficient to detach electrons from an atom or molecule. The possible effects on people may include: radiation sickness, burns, a weakening of the immune system, genotoxic changes, sterility, death.

If the energy of the radiation is not sufficient to cause ionisation, one speaks of non-ionising radiation. Non-ionising radiation covers electric, magnetic and electromagnetic fields as well as optical rays.
The effects of high-frequency fields on workers are determined by thermal effects (microwave cataract). With low-frequency fields the main effects are the irritation of the sensory, nerve and muscle cells. Alongside the direct effects there are indirect ones (for example leakage currents, electric charging) and the possible influences on devises (such as implants) which have to be noted.

Hazards due to optical radiation from artificial or natural sources consist primarily of damage to the eyes and skin.

Figure 7-1 gives an overview of the electromagnetic spectrum. The range of visible light is located at the boundary between ionising and non-ionising radiation. Electromagnetic fields can be characterised by the variables frequency f and wavelength λ. Both parameters are linked via the speed of light c = λ x f.

Vacuum and gauge pressure influence the intake or discharge of respiration gases. Vacuum at high altitudes, in aircraft or in vacuum chambers restricts the oxygen supply and, especially if there is a physical strain at the same time, it can lead to physiological disorders right through to serious altitude sickness and fatal pulmonary and cerebral oedemas. In the case of gauge pressure during diving and in the special foundation construction underwater, respiratory gases are enriched in the body, and they can cause life-threatening physiological disorders and damage to bone and muscle tissue, the circulatory functions, the central nervous system and the respiratory organs if there is too rapid a reduction in the pressure.

Further information is only available in German.