Abstract:
BACKGROUND AND PURPOSE: The iron and steel industry in South Africa has been identified as one of the highest
risk industries in terms of noise induced hearing loss (NIHL). The National Institute for Occupational Health was
commissioned by the Department of Labour to audit the current noise exposure levels and hearing conservation
practices in eight major producers of iron and steel, and to make recommendations regarding prevention
strategies.
METHODS: The audit was conducted in two parts: the noise exposure levels and hearing conservation practices
were assessed by the occupational hygiene department. The occupational medicine department assessed the
hearing conservation policies and procedures, reviewed employees’ medical records to ascertain the number of
NIHL cases, and conducted verification of audiograms on a sample of employees working in noise zones.
RESULTS: Area noise levels exceeding 105 dB(A) were measured in four of the eight workplaces. The estimated
average annual incidence of NIHL varied from 0.7 - 8.3/1000/year. All companies did baseline, periodic and exit
audiometric testing, but there were notable discrepancies between companies and verification audiograms and
differences of more than 20 dB(A) were found. Although information and training on noise was reportedly done
in all worksites, a high proportion of workers could not demonstrate correct fitting of hearing protection devices
or recall when last they were trained.
CONCLUSION: A detailed standard operating procedure should be implemented for medical surveillance for NIHL
with action timelines that initiate remedial processes prior to employee developing compensable disease.
Aggregated audiometric testing results should be communicated to managers and health and safety teams to
provide guidance to prioritise areas for control measures. A quality assurance programme for audiometric
testing must be implemented. An evaluation tool to measure the effectiveness of the noise and hearing
conservation training provided to employees, including contracted employees, should be adopted.
