Voice Complaints among Public Transport Workers in the Metropolitan Region of Belo Horizonte, Brazil

Abstract

Objective: To investigate the prevalence of voice complaints among bus transport workers in a metropolitan area in Brazil and examine whether sociodemographic and occupational factors were associated with this outcome. This study is part of a larger study that investigated the working conditions and health of drivers and conductors of urban transportation. Methods: The sample size (1,607 participants) was calculated by means of quotas and was stratified according to occupation (drivers and conductors) in the bus companies of Belo Horizonte, Betim and Contagem. Face-to-face interviews were facilitated by means of a digital questionnaire, applied by the interviewer using a netbook. The outcome variable was constructed from combining the responses to the following two questions: (1) Over the last two weeks, have you felt tired when speaking? (no/sometimes/every day). (2) Over the last two weeks, have you noticed any worsening of your voice quality? (no/sometimes/every day). Sociodemographic, lifestyle, occupational characteristic and health situation data were gathered. Results: The prevalence found was 29% overall: 24% for drivers and 34% for conductors. Attention was drawn to positive associations with the function of conductor and with reports of exposure to vibration and thermal discomfort. Among the individual factors, only female gender reached statistical significance. Conclusion: Risk factors exist that justify interventions to promote voice health within the urban transport sector under study. It would be appropriate to investigate whether vibration of the whole body would influence the functioning and morphology of the larynx.

A Review of Thermal Comfort Applied in Bus Cabin Environments

“…Still, in 2014, authors Assunção, Jardim, and Medeiros [52] innovated by studying the professionals working on buses. Aiming to investigate the prevalence of vocal health-related complaints by bus drivers and collectors in Brazil.…”

“…Thermal sensation [5,9-11,13,14,18,31,46- According to Table 7, most thermal comfort studies in bus cabin environments focused on the thermal sensation aspect. Of the 16 research papers directed at the most investigated aspect, 12 analyzed only the passenger cabins [5,[9][10][11]13,14,31,[46][47][48]53,55], two observed only the drivers [18], one focused on passengers and drivers [49], and two sampled drivers and ticket collectors [50,52].…”

“…Zhu et al [11] Air quality Pala [48] Not available Hossam, Fouad, and Abou-Zaid [9] Not available Zhang et al [13] Air quality and acoustics Makowiec-Dabrowska et al [18] Not available Zhu et al [14] Air quality Velt and Daanen [15] Not available Unal [49] Not available Pala and Oz [31] Not available Pimenta and Assuncao [50] Acoustics, acceleration, and luminous Ismail et al [19] Not available Ismail et al [51] Not available Assunção, Jardim, and Medeiros [52] Acoustics and acceleration Zhang, Zhou, and Zhang [5] Acoustics and acceleration Vollaro [10] Not available Lin et al [53] Not available Zhu, Demokritou, and Spengler [46] Air quality Khamis Mansour et al [16] Not available Shek and Chan. [17] Air quality Khamis Mansour et al [54] Not available Mui and Shek [47] Air quality Conceição et al [55] Not available…”

“…Zhu et al [11] Not informed Not informed Pala [48] ASHRAE 55 Gagge Model Hossam, Fouad, and Abou-Zaid [9] ASHRAE 55 and ISO 7730 PMV-PPD Zhang et al [13] Not informed Not informed Makowiec-Dabrowska et al [18] Not informed Not informed Zhu et al [14] Not informed Not informed Velt and Daanen [15] ISO 9886, ISO 10551, and ASHRAE 55 PMV-PPD Unal [49] ASHRAE 55 and ASHRAE 62 Adaptative Pala and Oz [31] ASHRAE 55 Gagge Model Pimenta and Assuncao [50] Not informed Not informed Ismail et al [19] Not informed Not informed Ismail et al [51] Not informed Not informed Assunção, Jardim, and Medeiros [52] Not informed Not informed Zhang, Zhou, and Zhang [5] Not informed PMV-PPD Vollaro [10] Not informed Not informed Lin et al [53] ISO 10551, ISO 14505-3, and ISSO 7726 PMV-PPD Zhu, Demokritou, and Spengler [46] ASHRAE 55 Not informed Khamis Mansour et al [16] ASHRAE 55 PMV-PPD Shek and Chan. [17] ASHRAE 55 Not informed Khamis Mansour et al [54] ASHRAE 55 PMV-PPD Mui and Shek [47] Not informed Not informed Conceição et al [55] ISO 7730 and ASHRAE 55 PMV-PPD Table 10 shows that the main international standards of thermal comfort (ISO and ASHRAE) were employed in a few studies, whereas it was not possible to identify the standards used by others.…”

“…Of the studies that intended to assess only the thermal comfort in bus cabins (see Table 9), six [10,16,18,19,51,54] did not specify or did not work with standard models but they remain relevant since an article is usually a summary of a larger research and many things are not mentioned in that summary or aimed to evaluate microclimate conditions in the bus cabins where the parameters of thermal comfort were not used in their amplitude. Moreover, of the studies that analyzed the comfort of drivers [18,19,[49][50][51][52], only Unal [49] employed a standard model to assess the drivers' cabins.…”