Task-based exposure assessment of noise in patrol police officers using task-attributable fraction metrics

Abstract Patrol police officers experience irregular, intermittent noise during routine public-facing duties, yet task-resolved exposure patterns are not well characterized. We conducted personal full-shift noise monitoring with 1-min logging over six days at an urban police substation in Seoul, Republic of Korea, obtaining 44 officer-shift measurements from 21 community patrol police officers. Shift-normalized 8-h time-weighted average (TWA) levels were calculated under Korean Ministry of Employment and Labor (MOEL) and American Conference of Governmental Industrial Hygienists (ACGIH) criteria. Dispatch records from the national 112 emergency call system were linked to minute-level measurements to quantify task-specific noise intensity during response periods and the Task-Attributable Fraction (TAF), defined as the proportion of total shift-integrated sound energy accumulated during minutes coded to dispatch-defined tasks, along with time share. All normalized 8-h TWA levels were below the respective occupational exposure limits (mean 61.5 dB(A) under MOEL and 72.3 dB(A) under ACGIH criteria), although full-shift maximum levels (LASmax) ranged from 93.2 to 122.7 dB(A). Mixed models accounting for repeated measurements showed that 8-h TWA levels clustered strongly within officers (intraclass correlation 0.52–0.65), whereas TAF showed no detectable between-officer clustering, indicating that its variability was primarily observed across shifts rather than between officers. Dispatch-related responses accounted for a mean of 44.5% of shift-integrated sound energy while occupying 22.8% of shift time, indicating that intermittent episodes can contribute disproportionately to full-shift exposure. Energy-based task attribution complements time-based metrics in characterizing patrol-duty noise exposure and may help identify tasks warranting targeted evaluation in future studies linking task-resolved metrics with health outcomes.