Risk assessment of hearing loss: a case study of an ice factory in Thailand

This study investigated workplace noise exposure, hearing status, factors associated with high-frequency hearing loss (HFHL) and occupational hearing risk among ice factory workers in Thailand. A cross-sectional study included 137 workers from seven ice factories in Pathum Thani Province. Workplace noise levels were measured across major production areas using the equivalent continuous sound pressure level over 8 h (L_Aeq,8h). Pure-tone audiometry was performed after at least 14 h of workplace noise avoidance. HFHL was defined as a binaural average hearing threshold >25 dB hearing loss at 3, 4 and 6 kHz. Logistic regression was used to identify associated factors. Workplace noise levels ranged from 82 to 92 dB(A), with 59.1% exposed to ≥85 dB(A). HFHL prevalence was 30.7%. Older age, current smoking and workplace noise exposure ≥85 dB(A) were independently associated with HFHL. Preventive measures based on the hierarchy of controls may help reduce occupational hearing risks in ice factories.