Submitted in fulfillment of the requirements for the degree of Doctor of Technology: Quality Management, Durban University of Technology, 2014. / Hearing conservation in the industrial setting has mainly focussed on the harmful effects of noise exposure on the auditory system. This study investigated the co-exposure to noise and ototoxic chemicals on the auditory system of workers engaged by labour brokers. It examined the adequacy of current occupational health and safety legislation to address chemically induced hearing loss and makes recommendations at a policy level to protect workers’ hearing at the workplace. This study is an exploratory cross-sectional field case study in an industrial setting. A sample of 300 workers was drawn from a rubber factory involved in the manufacture of components for the motor, shoe and plumbing industries in the metropolitan area of Durban. Purposive sampling was undertaken amongst a cohort of day shift workers which constituted the research subjects. The research tools used in the study included the completion of the NoiseChem questionnaire, conducting pure tone audiometric testing on research subjects, monitoring noise exposure levels and performing chemical air monitoring of the ambient environment. This study confirms that a segment of the research subjects were exposed to both ototoxic chemicals and noise. Chemical exposure of research subjects was within legal permissible limits in most instances. Noise exposure exceeded the noise rating limit of 85 dBA in certain work areas. Multiple regression analysis revealed that there was a slight trend towards co-exposure to chemicals and noise being risk factors for hearing loss with an odds ratio of 1.7 (95% CI = 0.34 – 8.57) but the p value was not significant. No significant association with hearing loss was evident for workers exposed to chemical only with odds ratio of 0.41 (95% CI = 0.11 – 1.53, p = 0.19) and noise only with odds ratio of 0.87 (95% CI = 0.32 – 2.31, p = 0.78). The study indicated that workers exposed to both ototoxic chemicals and noise may be more susceptible to hearing loss in their current jobs. The study draws attention to policy gaps in the Occupational Health and Safety Act and proposes changes to address the shortcomings. / D

A constante mudança nos meios de trabalho ocorre devido a evolução tecnológica e industrial. Entretanto, com o advento de tais inovações, dificilmente o trabalhador da indústria não é submetido aos mais variados riscos ocupacionais resultantes dos processos produtivos. Diante deste contexto, o presente estudo teve como objetivo principal avaliar os níveis de vibração e de ruído aos quais os trabalhadores de uma empresa do setor da construção civil, especializada na manutenção e reformas de pisos industriais, estavam expostos durante suas jornadas de trabalho em duas frentes de trabalho. As medições foram realizadas em locais e dias distintos nos municípios de Curitiba e de São José dos Pinhais, ambos no estado do Paraná. Para a avaliação da vibração ocupacional, utilizou-se um acelerômetro junto ao trabalhador e um sensor triaxial acoplado na empunhadura dos equipamentos objeto de estudo, que foram duas diferentes fresadoras de piso. Posteriormente os dados foram processados e comparados com o novo texto do Anexo no 08 da Norma Regulamentadora NR-15, apresentado para consulta pública pelo Ministério do Trabalho e Emprego entre os meses de janeiro e fevereiro de 2014. Já para a medição do ruído utilizou-se um dosímetro de ruído junto ao trabalhador, cujo resultado final possibilitou a comparação com o Anexo no 01 da mesma Norma Regulamentadora. Os resultados finais indicaram níveis de exposição excessivos, superiores aos limites de tolerância determinados pela Legislação, tanto para vibração quanto para o ruído, gerando insalubridade para os trabalhadores expostos, em todos os locais onde foram realizadas as medições. / The constant change in the means of work is done by technological and industrial developments. However, with the advent of such innovations, hardly the work of the industry is not subject to a variety of occupational hazards resulting from production processes. Given this context, the present study aimed to monitor the working hours of the employees of a company in the construction industry, specializing in industrial floor maintenance and renovations, as exposure of vibration and noise on two fronts work in the cities of Curitiba - PR and São José dos Pinhais – PR. The program took place in two locations and on different days. The workday adopted by the company is six hours daily. For the evaluation of vibration, we used accelerometer with the worker and coupled to the handle of the equipment object of study, a mill floor, triaxial sensor subsequently the data were processed and compared with the new text of Annex No. 08, NR 15, submitted for public consultation by the Ministry of Labour and Employment in the months of January and February 2014. As for noise measurement used a dosimeter with the worker, whose final results enabled comparison with the regulatory norm 15 - Annex No. 01. The final results indicate excessive exposure to the tolerance specified by the legislation, both vibration and sound pressure level, featuring unhealthy at all locations where measurements were performed.