Lifetime Vibration Dose (LVD) Correlates with Severity of Neurological Component of HAVS among Tyre Shop Workers in Kelantan, Malaysia.

INTRODUCTION:: Cumulative lifetime exposure to vibration is believed to contributes to more severe complications of HAVS.

OBJECTIVES:: To determine the prevalence of neurological component of HAVS and the correlation between lifetime vibration dose (LVD) and the neurological severity of HAVS among tyre shop workers in Kelantan.

METHODS:: A cross-sectional study involving 200 tyre shop workers from two districts in Kelantan. Part one data were collected at the field using questionnaire and hand-arm vibration was measured. Part two involved a set of hand clinical examinations (Purdue pegboard, Semmes-Weinstein Monofilaments and Two-point Discrimination tests) carried out for neurological component severity staging. LVD for each worker was calculated from data gathered in part one. For workers who had neurological symptoms, staging according to Stockholm Workshop Scales was done according to part two data. The strength of correlation between LVD and neurological stages was then determined using Spearman Correlation.

RESULTS:: The prevalence of neurological component was 37%. Spearman correlation between LVD and the neurological stages showed a moderate positive correlation.

CONCLUSION:: Cumulative lifetime exposure to hand-transmitted vibration is likely to be related to neurological severity of HAVS and therefore must be considered when assessing workers exposure to hand-arm vibration.