Hearing protection devices use and its relationship with hearing loss among steel industry workers of Samut Prakan Province, Thailand

Abstract

Objective: To investigate hearing protection devices (HPDs) use and its relationship with hearing loss among steel industry workers in Thailand. Materials and Methods: The present cross-sectional study included 93 eligible participants who are working in the designated high-noise-level zones, which is 85 or more A-weighted decibels [dB(A)] for eight hours time-weighted average, of the two factories. Self-report forms were used to obtain HPDs use by industry workers and noise exposure level was measured with Spark® (Model 706) noise dosimeter. Audiometric screening for hearing loss was performed at a regional hospital by the qualified technician. The hearing loss in each ear was defined if the average threshold level was found to have exceeded 25 dB(A) at high frequencies of 4 and 6 kHz. Results: The findings showed that 45.2% of workers used earplug, 16.1% used earmuff, and 38.7% used both, and most workers (55.8%) wear HDPs regularly, for six of seven days per week. Fifty seven percent of workers wear HDPs for more than 60% time of an 8-hour work shift. Most workers (75.2%) have hearing loss. Conclusion: The authors' result revealed that almost half of workers used hearing protection devices and most workers use HPDs during the 8-hour work time. Abnormal hearing ability were found among workers. The education program such as the hazards of noise on potential auditory loss, a noise education training program and full use of HPDs are encouraged to prevent effect of noise on workers.