Title: Physical symptoms and mental health status in deep underground miners: A cross-sectional study

Abstract

Objectives: To reveal the physical symptom changes and their correlations with mental health status in deep underground miners. Methods: A total of 286 deep underground miners completed a cross-sectional questionnaire study at China Pingmei Shenma mine complex. The questionnaire includedsociodemographics, self-reported physical symptoms,underground adverse environmental factors and theSymptom Checklist-90-Revised (SCL-90-R). Five environmental parameters of one deep mine were also measured. Results: Data from266 valid questionnaires were analyzed. The three most frequent complaints about underground adverse conditions were moisture [62.03% (165/266)], dim light [45.86% (122/266)]and high temperature [42.11% (112/266)]. Fatigue [40.22% (107/266)], hearing loss [34.96% (93/266)] and tinnitus [31.58% (84/266)] were reported to be the threemost commonphysical symptoms. Insomnia was reported in 204 participants (76.69%) mainly due to the difficulty of falling asleep [42.35% (84/204)] and dreams [39.70% (81/204)]. Mean scores of SCL-90-R subscales including somatization, anxiety, phobic anxiety, psychoticism and paranoid ideation were elevated compared to Chinese norms, while there was diminished interpersonal sensitivity.Univariate analyses indicated that the threemost common physical symptoms were associated with poorer SCL90-R scores. With increasing depth below ground, air pressure, relative humidity, CO2 concentration and temperature rose, while total γ radiation dose-rate decreased. Conclusions: The physical and mental health status of deep underground miners was poorer than the general Chinese male population. Some adverse environmental factors were identified that may have influenced health status. Measures are suggested to improve the deep underground working environment.