Quantitative thermal perception thresholds relative to exposure to vibration

Area of Science:

• Occupational health
• Sensory neuroscience
• Ergonomics

Background:

• Hand-intensive work often involves vibration exposure, potentially affecting workers' sensory functions.
• Disturbed thermal perception is a concern in occupational settings, but its relationship with vibration exposure requires further investigation.

Purpose of the Study:

• To assess the risk of disturbed thermal perception due to vibration exposure.
• To investigate a potential exposure-response relationship for thermal perception.
• To analyze the link between thermal perception and sensory symptoms.

Main Methods:

• A cross-sectional study involving 123 vibration-exposed and 62 non-exposed male workers.
• Quantitative sensory testing of thermal perception (cold, warmth, heat pain) on the thenar eminence and digits.
• Measurement of personal energy equivalent exposure to vibration according to International Standards Organisation (ISO) 5349.

Main Results:

• Increased risk of reduced thermal perception was observed at all tested sites, with higher risk for thenar measurements.
• Each 4000 mh/s² yearly increase in cumulative vibration exposure raised the risk of a wider neutral zone by 18%.
• Workers with nocturnal paresthesia showed a 2.7-2.8 times higher risk of increased neutral zones at the thenar eminence.

Conclusions:

• Cumulative vibration exposure is linked to thermal sensory impairment.
• The observed effects occurred at vibration levels below the current guiding standard.
• Quantitative sensory testing can identify thermal sensory hazards in vibration-exposed workers.