Effect of hand-transmitted vibration on fingertip thermotactile perception threshold among mine drilling workers

Background The threat to workers' health by hand-transmitted vibration is more and more serious, but the basis for diagnosing small sensory fiber neuropathy in patients with hand-arm vibration disease is insufficient.

Objective Through measuring fingertip thermotactile perception thresholds (TPTs) among mine drilling workers, this study aims to explore the application value of TPTs in occupational health examination of hand-arm vibration disease.

Methods A cross-sectional study was performed among workers from 26 mines in Enshi, Hubei, and they were divided into a vibration-exposed group with hand-transmitted vibration exposure and a control group without such an exposure. TPTs (cold and warm) were measured with an HVLab vibrotactile perception meter and the results were compared between the two groups.

Results All the investigated subjects were male. The mine drilling workers' dominant (16.3-19.1m·s^-2) and non-dominant (8.3-14.4m·s^-2) hand exposure levels of hand-transmitted vibrationa_hw(4) exceeded the national occupational exposure limit. In the control group, the cold TPT of index finger of the dominant hand(26.92±3.10)℃ was higher than that of little finger(23.52±4.24)℃ (P < 0.05); the cold TPT of index finger of the non-dominant hand(26.06±3.35)℃ was also higher than that of little finger(23.12±3.96)℃ (P < 0.05). In the vibration-exposed group, the cold TPT of index finger of the dominant hand(25.02±4.41)℃ was higher than that of little finger(21.39±5.23)℃ (P < 0.05); the cold TPT of index finger of the non-dominant hand(25.01±3.98)℃ was also higher than that of little finger(21.50±4.97)℃ (P < 0.05). Compared with the control group(40.80±4.37)℃ and (41.72±3.78)℃ respectively, the warm TPTs of index fingers(42.20±4.39)℃ and little fingers(43.22±3.96)℃ of the vibration-exposed group were higher (P < 0.05). Compared with the control group(26.48±3.24)℃ and (23.32±4.08)℃ respectively, the cold TPTs of index fingers(25.02±4.17)℃ and little fingers(21.45±5.07)℃ of the vibrationexposed group were lower (P < 0.05).

Conclusion The quantitative analysis of thermotactile perception threshold is helpful to evaluate the damage of small sensory fibers in workers with hand-transmitted vibration exposure.