This study used data from the 5th Korean Working Conditions Survey (KWCS), to analyze the association between occupational noise and vibration exposure, and anxiety. Our findings suggest that exposure to noise, and to both noise and vibration, have a more prominent effect on anxiety than exposure to vibration alone.
Similar to previous studies , there was a significant positive relationship between anxiety and noise exposure. A study conducted in Egypt found that airport workers who had a higher occupational exposure to noise showed more prominent anxiety symptoms . Further, this study found that combined noise and vibration had a significant influence on anxiety. This is in line with a previous study by Oldenburg , which showed that the occurrence of psycho-emotional strain increased significantly with exposure to noise and vibrations simultaneously. In addition, the prevalence of anxiety was higher in females than in males in our study. This is consistent with previous findings, which showed that women are more vulnerable to mental health problems than men . However, the anxiety OR was higher in males than females in the noise exposure group, and the simultaneous noise and vibration exposure group. This could be owing to the fact that male participants are more likely to be exposed to hazardous occupational conditions than female participants, as reported in prior studies, and thus, the aftermath is more likely to be damaging among males .
Exposure to both noise and vibration can cause dysfunctions in both psychological and physical aspects linked to the nervous system . Symptoms such as headache/eyestrain, fatigue, and insomnia are related to the nervous system disorders that are known to have connected mechanisms . Persistent exposure can continuously agitate the autonomic nervous system, resulting in a sustained central autonomic activation and stimulation of sympathetic nervous activity. For nervous system-related symptoms, the peripheral nervous system induction could be a major risk factor . As anxiety is linked with the autonomic nervous system involved in the human stress response, other symptoms could be different stressors, all contributing to the anxiety.
Our results showed higher anxiety among women in pink collar jobs. These characteristics can be attributed to job differences. In the case of females, many were working in pink-collar jobs . Many pink-collar jobs are a part of the service sector, in which exposure to noise and vibration is frequent. For instance, telemarketers are continuously exposed to noise and vibration through the ringing of the phone., which could result in a higher chance of anxiety due to the work environment .
There was also an age difference observed between males and females. The probability of anxiety was higher among males below the age of 39. These could be owing to the fact that younger workers are likely required to undertake more difficult work compared to their seniors . Additionally, previous studies have reported that well-being and mental health increases with age .
A dose–response relationship was seen in the variable of interest subgroup analysis, examining the relationship of exposure to noise or vibration with anxiety. Among males, the risk of anxiety increased with increased noise and vibration exposure, both individually and combined, signifying a dose–response relationship. This was observed at all levels of exposure. However, this was only observed at a milder degree of exposure among females. This may be explained by the findings of a previous study, which showed that even within the same jobs, females were less exposed to noise than males, owing to differences in tasks . This is in line with the results of the current study. According to many prior studies, the synergistic effect of noise and vibration has been shown to impact on health outcomes, such as cognitive performance, hearing loss, and headache/eyestrain . In animal studies, conducted by Hamernik, and in an experimental study conducted by Huang and Griffin , a prediction model was created for 24 healthy young people in order to examine the level of discomfort caused by exposure to continuous, whole-body vibration and noise. It was concluded that the negative psychological effects increased owing to the combination of noise and whole-body vibration, which included increased stress, discomfort, or strain .
This study has several limitations. First, as it is a cross-sectional survey, causalities could not be clearly confirmed. Second, the data were self-reported, and it was not possible to confirm the participants’ level of exposure, level of intensity, or the exact timeline of the noise and vibration. Owing to the question limitations, the exact decibels regarding noise exposure, or the exact amplitude, frequency, or duration regarding vibration, could not be observed. Third, the KWCS did not contain relevant information, such as drinking or smoking habits, and we were therefore unable analyze these factors. Fourthly, we could not investigate specific anxiety disorders, such as panic disorder, social phobia, and obsessive compulsive disorder . It would be beneficial for further studies to include a more detailed examination of anxiety disorders in the context of occupational exposure to noise and vibrations. Fifthly, there could be different types of vibration, such as whole-body vibrations, or hand–arm vibrations, which were not considered in this study .
Despite its limitations, this study also has several strengths. Firstly, it used the most recent data available, which was nationally representative and collected through rigorous, systematic multistage sampling. Therefore, these results are representative of workers in Korea. Secondly, to our knowledge, this is the first study, in South Korea, to examine the relationship between exposure to noise and vibration and anxiety using KWCS data.