[The impact of hand-transmitted vibration from municipal maintenance workers on health]

Objective: To investigate the health effects of hand-transmitted vibration operations on municipal maintenance workers, and to provide a scientific basis for effective prevention and control of hand-transmitted vibration hazards in the future. Methods: In October 2023, using the cluster sampling method, 96 municipal maintenance workers exposed to hand-transmitted vibration in a certain city were selected as the research subjects. The personal history, occupational history and other information of the workers were collected, and the scores of symptoms such as hand numbness, hand pain, and white fingers were calculated. The 4 hour and 8 hour energy equivalent frequency weighted vibration acceleration values were calculated, and the cumulative vibration exposure level (CVEL) was estimated and used for grouping. Combined with the results of the two-point discriminatory test and cold water rewarming test on both hands, the CVEL of hand-transmitted vibration was analyzed as a continuous variable and a categorical variable to explore the impact of CVEL of hand-transmitted vibration on the health of the workers. Results: The CVEL of hand-transmitted vibration for municipal maintenance workers was (4.64±0.35) m/s(2). Among them, the low-exposure group (33 people) had CVEL<4.469 m/s(2), the middle-exposure group (30 people) had 4.469-4.842 m/s(2), and the high-exposure group (33 people) had CVEL>4.842 m/s(2). After adjusting for confounding factors such as age and working years, the CVEL of hand-transmitted vibration of municipal maintenance workers was positively associated with the score of hand symptoms (β=1.18, P=0.043), and positively associated with the two-point discriminatory threshold of both hands (β(left hand)=2.34, β(right hand)=2.75, P<0.001), but negatively associated with the 10-minute cold water rewarming rate of the left hand (β=-17.95, P=0.017). Compared with the low-exposure group of hand-transmitted vibration CVEL, the two-point discriminatory threshold of both hands in the middle and high-exposure groups increased significantly (middle-exposure group: β(left hand)=0.94, β(right hand)=1.03, high-exposure group: β(left hand)=2.19, β(right hand)=1.97; P<0.001) . Conclusion: The increase in hand-transmitted vibration CVEL is associated with peripheral neurological dysfunction, impaired microcirculation and aggravated hand symptoms. The health risks of workers with high exposure levels of hand-transmitted vibration are particularly prominent.