Evaluation of Noise Levels on the Health of Mine Workers in the Drilling Machine Area

Abstract

This study aimed to describe noise levels in the drilling machine area, characterize noise dispersion patterns, identify workers' self-reported health complaints, and recommend appropriate noise control measures at PT. Dempo Bangun Mitra. A descriptive-analytic study with a cross-sectional design was employed. Data were obtained from direct noise measurements using a Sound Level Meter at 11 observation points located 0–100 meters from the noise source and questionnaires administered to 20 workers. Questionnaire responses were summarized descriptively to determine the frequency and percentage of reported health complaints and hearing protection use. The results showed that 9 of the 11 measurement points (81.82%) exceeded the 85 dB(A) reference limit. The highest noise level was 105.43 dB(A) at 0 meters, while the lowest was 71.63 dB(A) at 100 meters. An iso-dB(A) map showed that the highest noise concentrations occurred in the western to northwestern sections of the study area, with measured noise levels falling below 85 dB(A) at distances of approximately 90 meters and beyond. This distance represents an observation specific to the study site and should not be interpreted as a universal safety threshold. All respondents reported occasional ear discomfort, ringing in the ears, and sleep disturbances; 75% reported headaches, 60% reported difficulty concentrating, and 80% reported being disturbed by noise. Consistent use of hearing protection equipment was reported in only 55% of cases. These descriptive findings indicate the coexistence of elevated noise levels and self-reported health complaints but do not establish a causal relationship between noise exposure and these complaints. The findings support a tiered noise control strategy incorporating engineering controls, exposure duration management, worker rotation, appropriate hearing protection, regular noise monitoring, and periodic audiometric testing, formalized through a Standard Operating Procedure (SOP). The cross-sectional design limits causal interpretation, and defining an appropriate safe working zone requires further assessment of exposure duration, operational variability, and noise levels measured at representative times.