Abstract
The burden of occupational Noise-Induced Hearing Loss (NIHL) remains on the rise, especially in developing countries. It has been reported that 16% of the global adult-onset hearing loss or over 4 million Disability-Adjusted Life Years (DALYs) is attributed to occupational noise exposure. Noise-Induced Hearing Loss (NIHL) is one of the highest recorded occupational diseases, despite being preventable. The purpose of this study was to determine the effectiveness of a Hearing Conservation Program (HCP) in preventing or reducing audiometric threshold changes among vector control workers. This is a cluster randomized controlled trial involving 183 vector control workers. The HCP was implemented among participants of the intervention group. The workers ' annual audiometry for 2017 (pre-intervention) was used as the baseline audiometry for this study. The outcome measured participants ' hearing threshold levels at the frequencies 500, 1000, 2000, 3000, 4000, 6000, and 8000 kHz assessed using calibrated audiometric booths. Personal monitoring results of workers handling the thermal fogging machine from each group showed an 8- hour Time Weighted Average (TWA) of 87.3 dB(A) and 93.1 dB(A), respectively. The left ear mean hearing threshold in the intervention group showed significant improvement for all frequencies post-intervention, with the most considerable reduction seen at 6000 Hz with a 5.4 dB reduction and is statistically significant (p<0.05). Positive values of intergroup mean difference were observed at 2000 Hz (0.97 dB) and 4000 Hz (2.24 dB), with the most significant improvement seen at the latter frequency. Meanwhile, for the right ear, the intervention group showed an increase in the mean hearing threshold for all frequencies, with the most significant increase observed at 3000 Hz with a 3.7 dB increase that was statistically significant. The mean hearing threshold remained almost similar at 4000 Hz and 6000 Hz with only a minimal 0.4 dB and 0.2 dB increase after three months of post-intervention. The control group showed a reduction in mean hearing threshold after three months for all frequencies except 6000 Hz and 8000 Hz, with the most significant reduction seen at 500 Hz with a 3.5 dB reduction and found to be statistically significant (p<0.05). However, the mean hearing threshold remained almost similar at 3, 4, and 8 kHz after three months. As for the intergroup mean difference, negative values were observed at all frequencies except 6000 Hz (1.08) but not statistically significant. Vector control workers in the Ministry of Health (MOH), Malaysia, are exposed to hazardous noise emitted by the thermal fogging machines well above the 85 dB(A) daily noise exposure level recommended by the Malaysian Occupational Safety and Health Act (OSHA) (Noise Exposure) Regulations 2019. Therefore, there is a need for a comprehensive HCP to be implemented at all DHO for vector control workers.
Links
- https://apcph.cphm.my/wp-content/uploads/2022/07/APCPH2022-P-57.pdf
- https://apcph.cphm.my/wp-content/uploads/wpforms/1176-1e04940bb5d885bf8711ed1909[...]
BibTeX (Download)
@proceedings{APCPH2022-P-57,
title = {Hearing Conservation Program for Vector Control Workers: Short- Term Outcomes from a Randomized - Cluster Controlled Trial},
author = {Rama Krishna Supramanian and Marzuki Isahak and Noran Naqiah Hairi},
url = {https://apcph.cphm.my/wp-content/uploads/2022/07/APCPH2022-P-57.pdf
https://apcph.cphm.my/wp-content/uploads/wpforms/1176-1e04940bb5d885bf8711ed19095a89ed/APCPH-Poster-ab39831dd4a04be82437b1fbfaf1002e.pdf},
year = {2022},
date = {2022-08-02},
urldate = {2022-08-02},
issue = {7},
abstract = {The burden of occupational Noise-Induced Hearing Loss (NIHL) remains on the rise, especially in developing countries. It has been reported that 16% of the global adult-onset hearing loss or over 4 million Disability-Adjusted Life Years (DALYs) is attributed to occupational noise exposure. Noise-Induced Hearing Loss (NIHL) is one of the highest recorded occupational diseases, despite being preventable. The purpose of this study was to determine the effectiveness of a Hearing Conservation Program (HCP) in preventing or reducing audiometric threshold changes among vector control workers. This is a cluster randomized controlled trial involving 183 vector control workers. The HCP was implemented among participants of the intervention group. The workers ' annual audiometry for 2017 (pre-intervention) was used as the baseline audiometry for this study. The outcome measured participants ' hearing threshold levels at the frequencies 500, 1000, 2000, 3000, 4000, 6000, and 8000 kHz assessed using calibrated audiometric booths. Personal monitoring results of workers handling the thermal fogging machine from each group showed an 8- hour Time Weighted Average (TWA) of 87.3 dB(A) and 93.1 dB(A), respectively. The left ear mean hearing threshold in the intervention group showed significant improvement for all frequencies post-intervention, with the most considerable reduction seen at 6000 Hz with a 5.4 dB reduction and is statistically significant (p\<0.05). Positive values of intergroup mean difference were observed at 2000 Hz (0.97 dB) and 4000 Hz (2.24 dB), with the most significant improvement seen at the latter frequency. Meanwhile, for the right ear, the intervention group showed an increase in the mean hearing threshold for all frequencies, with the most significant increase observed at 3000 Hz with a 3.7 dB increase that was statistically significant. The mean hearing threshold remained almost similar at 4000 Hz and 6000 Hz with only a minimal 0.4 dB and 0.2 dB increase after three months of post-intervention. The control group showed a reduction in mean hearing threshold after three months for all frequencies except 6000 Hz and 8000 Hz, with the most significant reduction seen at 500 Hz with a 3.5 dB reduction and found to be statistically significant (p\<0.05). However, the mean hearing threshold remained almost similar at 3, 4, and 8 kHz after three months. As for the intergroup mean difference, negative values were observed at all frequencies except 6000 Hz (1.08) but not statistically significant. Vector control workers in the Ministry of Health (MOH), Malaysia, are exposed to hazardous noise emitted by the thermal fogging machines well above the 85 dB(A) daily noise exposure level recommended by the Malaysian Occupational Safety and Health Act (OSHA) (Noise Exposure) Regulations 2019. Therefore, there is a need for a comprehensive HCP to be implemented at all DHO for vector control workers.},
howpublished = {published online at https://apcph.cphm.my},
note = {Type: POSTER PRESENTATION; Organisation: Department of Social and Preventive Medicine, Faculty of Medicine, Universiti Malaya},
keywords = {Audiometry, Hearing Conservation, Noise-induced Hearing Loss, Vector Control Worker},
pubstate = {published},
tppubtype = {proceedings}
}