Evaluation of Conventional Floor-to-Floor Prediction Models for Train-Induced Noise and Vibration and Their Association with Residents' Depressive Symptoms.
Although underground metro systems enhance urban transportation, their potential mental health impacts remain a public concern.
This study aims to investigate the association between residential floor height, subway-induced noise and vibration, and depressive symptoms, and to evaluate the accuracy of conventional floor-to-floor prediction models.
Indoor noise and vibration were measured on all floors of a multistory building adjacent to the Tehran Metro. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9).
Noise and vibration levels decreased with increasing floor height, demonstrating a clear exposure gradient. Higher exposure was significantly associated with greater depressive symptom severity. PHQ-9 scores declined with floor level in the adjusted model ( β = -0.33 points per floor, P = 0.011). The Federal Transit Administration (FTA) predictions closely matched measured vibration but overestimated noise, with greater deviation at higher floors ( P = 0.002). Notably, PHQ-9 scores exceeded the clinical cutoff (≥10) on all floors, including those below FTA allowable exposure limits.
The floor-to-floor reductions averaged approximately 2 dB for vibration and 2.6 dB for noise. Current predictive frameworks and uniform allowable exposure limits may underestimate the long-term psychological impacts across building floors. Refinement of exposure criteria, together with frequency-based noise evaluation, may better protect residents' mental health.
This study aims to investigate the association between residential floor height, subway-induced noise and vibration, and depressive symptoms, and to evaluate the accuracy of conventional floor-to-floor prediction models.
Indoor noise and vibration were measured on all floors of a multistory building adjacent to the Tehran Metro. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9).
Noise and vibration levels decreased with increasing floor height, demonstrating a clear exposure gradient. Higher exposure was significantly associated with greater depressive symptom severity. PHQ-9 scores declined with floor level in the adjusted model ( β = -0.33 points per floor, P = 0.011). The Federal Transit Administration (FTA) predictions closely matched measured vibration but overestimated noise, with greater deviation at higher floors ( P = 0.002). Notably, PHQ-9 scores exceeded the clinical cutoff (≥10) on all floors, including those below FTA allowable exposure limits.
The floor-to-floor reductions averaged approximately 2 dB for vibration and 2.6 dB for noise. Current predictive frameworks and uniform allowable exposure limits may underestimate the long-term psychological impacts across building floors. Refinement of exposure criteria, together with frequency-based noise evaluation, may better protect residents' mental health.