Indra Thirugnanam1, Arul Sundaresh Kumar2, Padmanabam3, Valarmathi4, Ramesh5
Occupational settings and transport is the prominent sources of noise that affect health. Noise-Induced Hearing Loss (NIHL) is sensory neural hearing loss due to exposure to intense impulse or continuous sound. Exposure to noise can be occupational or non-occupational. The audiologic profile of NIHL is the presence of sensorineural hearing loss that is most pronounced in the high-frequency region between 3,000 Hz and 6,000 Hz of the audiogram and the greatest amount of hearing loss is typically around the 4,000-Hz region (i.e. 4,000 Hz dip).1 The main causes of hearing loss resulting in deafness in adults in India are excessive noise, age and ear infection. Although, occupational hearing loss is a well-recognized occupational condition arising from industries or occupations with exposure to high noise levels (e.g., airline crew),2 it has not been fully evaluated in occupations where the risk is not so overt such as the police force. Police officers are potentially exposed to multiple sources of noise including vehicle horns, gunfire, barking from police dog and traffic noise.3 The aim of the study is to study the incidence of noise-induced hearing loss amongst traffic police personnel who came for master health checkup.
MATERIALS AND METHODS
A total of 812 constables were examined. All individuals underwent a complete general, systemic and ENT examination to detect any obvious pathology, which may result in hearing loss. A detailed history was taken regarding the number of years of service in traffic branch, place of duty, past history of ear disease or intake of ototoxic drugs. Subjects suffering from preexisting ear disease such as CSO, OME, otosclerosis and suffering from URI has been excluded. Policemen suffering from hypertension and diabetes were also excluded. Remaining 774 was included in the study. This study was approved by the institutional ethical committee, Government Theni Medical College. Written consent was obtained from all the policemen participating in study. All the individuals were subjected to pure tone audiometry to detect the degree and type of hearing loss. The subjects in the study had undergone pre-enrolment medical examination and had normal hearing at the time of enrolment. Settings and Design- A study was undertaken by the Department of ENT, Government Theni Medical College, Theni, during June 3, 2015, to July 21, 2015. The subjects for this study were the police personnel who came for master health checkup.
A significant number of personnel were detected to be suffering from NIHL. No significant relationships was found between hearing loss and the age group of the individuals. There was an even distribution of hearing impaired individuals in all age groups. Those personnel who had less than 2 years’ service in the traffic branch had slightly less (60.3%) incidence of hearing loss as compared to others who had a higher incidence of approximately 85%. The hearing loss was mild in case of inspectors and more than 40 dB in constables. It was unilateral in (30.8%) individuals and bilateral in (69.2%) individuals. These types of audiometric pattern were encountered- 1) Descending curve; 2) Hearing loss in frequency beyond 4000 Hz; 3) A pattern of audiometric notching was seen at 4000 Hz or 6000 Hz.
A significantly large number of subjects in this study showed sensorineural hearing loss, which was of moderate-to-severe intensity in as many as of the individuals. It was bilateral in majority of the subjects and was directly related to the duration of exposure. In view of the high incidence of acoustic damage, a number of preventive measures were suggested like rotation of beat of traffic personnel between high- and low-noise intensity areas, use of personal ear protectors like ear defenders or ear muffs and creation of awareness among exposed individuals about the hazards of noise pollution.