Análise das condições acústicas de unidades de suporte móveis: um enfoque na saúde do trabalhador

Abstract

Objective: To determine and analyze the acoustic conditions of ambulances, their impact on hearing health and quality of workers' life and also suggest improvements to the acoustics noise control on the vehicle. Methods: This was descriptive cross sectional study in five steps. In the first step measurements were performed in ambulance for analysis of acoustic conditions including measurements of reverberation time, airborne noise insulation and equivalent continuous sound level produced by the engine and siren. In the second step measures sound pressure level were performed in the cabin of the ambulance emergency while traveling. In the third step analysis of the exposure of a worker to noise during the workday. In the fourth stage two questionnaires were applied to workers, one related to the history of life and occupation, presence of auditory and non-auditory symptoms, among other investigations of possible causes of hearing loss, and the other relating to workers' perception about the quality of life. In the last step based on analysis of data collected were proposed measures for noise control in the vehicle and preserve the workers health. Data was analyzed statistically. Results: An average reverberation time of 0.37 s was found for the ambulance cabin. The total airborne sound insulation in the rear panel was smaller. The noise level inside the ambulance due to ambulance motor operation ranged from 61.5 dB(A) (1000rpm) to 70.8 dB(A) (3000 rpm) and the noise level due to operation of the siren was equal to 74.9dB(A) with a parked ambulance. The average equivalent sound level for 12 trips exceeded 85 dB(A), above the rate allowed by NR 15, with the high noise is associated with traffic conditions and use of siren. The most frequently reported symptoms were hearing tinnitus and intolerance to loud sounds. Most non-auditory symptoms were checked irritability, headache, difficulty in communicating and sleeping. Statistically significant difference was observed when analyzing the relationship between self-perception of drivers and nursing staff on hearing acuity, tinnitus, irritability and difficulty of communication, were the most reported symptoms presented by category of drivers. The WHOQOL - Bref, which measures the quality of life of respondents according to domains: Physical, Psychological, Social Relationships and Environment, observed lower values in the environment field, which confirms the impact of environmental conditions experienced in work on quality of life of these professionals and still observed a statistically significant difference when comparing drivers and nurses in relation to the environmental domain. Conclusion: The acoustic conditions of the mobile support unit are not appropriate because a negative impact on hearing health and quality of life of employees, as may produce psychological reactions in the sick being transported. Therefore, there is a need to develop policies to improve sound insulation in ambulances and focused on general health preventive actions aiming at the preservation and adaptation of the quality of life of these professionals.