INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 1, No 5, Copyright 2010 All rights reserved Integrated Publishing Association

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1 INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 1, No 5, 2011 Copyright 2010 All rights reserved Integrated Publishing Association Research article ISSN Working in Noise Environment: An Investigation of Hearing Quality of Drivers in Morogoro Municipality, Department of Physical Sciences, Faculty of Science, Sokoine University of Agriculture (SUA), P.O. Box 3038, Morogoro, ABSTRACT The present study has been carried out to assess the hearing quality of commuter bus and taxi drivers in the fast growing Municipality of Morogoro,. The study utilized a structured questionnaire and was carried out among 160 drivers randomly selected in August and September The questionnaire included questions regarding the self assessment of the drivers about their hearing ability, past and present exposure to loud sound and the use of noise protective gears. The questionnaire was filled up by the respondents at a close supervision and the data were analysed using simple descriptive statistics. The results show that most divers aged below 35 years and have been exposed to the traffic noise environment for 2 to 5 years. Nearly 4% of the respondents felt that their hearing ability was below average and complained of regular tinnitus. The results also show that only 17.5% used noise protective gears and that too, not often. Reasons for non usage of protective gears (earplugs, earmuffs and canal caps) included awareness (24.4%), non availability (50%), personal dislike (8.1%) and headache caused by its use (17.5%). Large percent (82.5% of the drivers did not use any method to reduce exposure to noise, while remaining used fingers or hands at time of loud noise to avoid noise exposure. The self assessment of hearing by the commuter bus and taxi drivers in Morogoro Municipality suggests that most of the drives have normal hearing. However, this study suggests a systematic study with audiometry of these population groups be carried out in future. Keywords: Noise pollution, Exposure, Urban transport, Municipality. 1. Introduction The world technological advance has brought many conveniences on the community; it has also resulted in many health effects including air and noise pollution. The automobiles are an important source of not only air pollution but also of a significant proportion of noise pollution. In the present study the commuter bus (hereafter called daladala) mean a bus used for short distance public transport purposes whose roles and specifications are not clear cut, and vary with operator and Municipality zone while a taxi is a type of car for hire used by a single passenger or small group of passengers to take them where they want to go in exchange for money. The commuter bus and taxi drivers are engaged in transporting passengers, and most of their time they are exposed in noisy environment. The daladala drivers spend most of their time during working hours in roadway and/or in bus stands while the taxi drivers park their cars to wait for passengers mainly in taxi/bus stands or stops. Therefore, these drivers are at high risk to be affected by traffic noise and other urban noise (Janssen et al., 2001). The majority of drivers remain unaware of the health effects of noise on their hearing ability as this is an insidious process and takes long time to become overt. Received on December, 2010 Published on January,

2 Noise health effects include both the auditory as well as non auditory effects (Küzli et al., 2000; Pope and Dockery, 2006; Bogoch et al., 2005). Many studies around the world have been carried out in different categories of population and workplaces on the impacts of noise pollution (Bluhm et al., 2004; Ouis, 2002; Ohrstrom, 2004). However, in the auditory effects of noise generated by automobiles among the daladala and taxi drivers have never been explored. This may be one of the reasons for not providing noise protection gears to this group of work force and other groups which are also exposed to high noise level during their working time. However, the need should be felt by the drivers themselves and this can happen only when they are more of the noise pollution problem and associated health effects. With this background, the present study was carried out to investigate the hearing quality of daladala and taxi drivers in Morogoro Municipality. 2. Materials and Methods A cross sectional study was conducted to daladala and taxi drivers in August and September 2010 in Morogoro Municipality. The drivers were randomly selected and given questionnaire to be filled. The questionnaire included questions regarding the self assessment of the drivers about their hearing ability, past and present exposure to loud sound and the use of noise protective gears such as earplugs, earmuffs and canal caps. The questionnaire was filled up by the respondents at a close supervision so as to avoid the influence of one s results by the other respondent or person. The data analysis was carried out using simple descriptive statistics. 3. Results 3.1 Demographic characteristics of drivers The demographic characteristics of drivers who participated in this study are shown in Table 1. All interviewed drivers were male with majority being aged less than 35 years and had primary education qualification. More than half of the drivers (53%) have affirmed that they had been driving daladala or taxi for a period of between 2 and 5 years. 3.2 Assessment of hearing status The self assessment of hearing ability by the daladala and taxi drivers are shown in Table 2. Virtually similar respond to the questions in the questionnaire from the two groups of respondents have been observed. Nearly 4% of the respondents felt that their hearing ability was below average, while about 74% believed that their hearing ability was good and above average. However, the supplementary questions to assess the hearing ability revealed a slightly different picture. About 7% of respondents described to usually miss a lot when conversing with someone on phone, and 2.5% reported similar condition while talking to someone in a crowd. For the question of sound volume when watching television or listening to a radio, 10% reported that usually they keep the sound louder for them to hear properly. 815

3 Table 1: Demographic characteristics of drivers in Morogoro Municipality Characteristics Daladala Drivers Taxi drivers Total N % N % N % Age (in years) < > Duration of exposure (in years) < > Education Primary Ordinary level Advanced level Table 2: Self assessment of hearing status of drivers in Morogoro Municipality Characteristics Daladala Drivers Taxi drivers Total N % N % N % Quality of hearing Good Above average Average Below average Hearing over phone Without difficulty Do miss some conversation Miss a lot of what is said Hearing in crowd Without difficulty Do miss some conversation Miss a lot of what is said Sound of TV/Radio Usually louder Usually same loudness Usually a little softer Indicate of talking loudly to others Yes No Often other people to talk louder to them (drivers) Yes No Tinnitus most of the time

4 Table 2 also shows that some respondents (drivers) indicated that other people tell them they were talking louder, while 34% felt that people regularly have to talk louder with them so as to hear properly. Complain of regular sound in one ear or both ears, such as buzzing or whistling (tinnitus) occurred to about 4% of the respondents who experienced it during working hours only. 3.3 Use of noise protective gears Table 3 shows the distribution of the respondents according to the usage of personal noise protective gears. About 17% of the respondents reported to have used the noise protective gears such as earplugs, earmuffs and canal caps but not often. Awareness and non availability of these protective gears was the common reason for its non usage as reported by 74.4% of the respondents. However, other reasons for non usage included personal dislike (8.1%) and headache caused by its use (17.5%). Nearly 91% of the respondents did not use any method to reduce exposure to noise, while the remaining used fingers or hands at time of loud sound to avoid noise exposure. However, out of these respondents using other methods, 75% felt that on average these methods helped. Table 3: Assessment of use of noise protective gears among drivers Characteristics Daladala Drivers Taxi drivers Total N % N % N % Ever use earplugs or muffs or canal caps? Yes No Regularity of usage Rarely Never Reason for non usage Awareness Not available Dislike Cause of headache Other personal protective methods Don t use anything Hands/Fingers in loud noise Effectiveness of these other protective methods On average help Less better than earplugs or earmuffs or canal caps Discussion 817

5 This study revealed that about 88% of the drivers were in the economically productive age groups (< 45 year) and if they suffer from hearing disability at this age, they would have to live with that disability throughout their life. Fortunately, their duration of exposure was less (< 5 years) and so not much could have been lost and if effective measures could be taken at that stage, health hazards could be well prevented. The prevalence of reduced hearing among respondents was 3.8%. This could be due to ignorance about the health effects caused by continuous exposure to noise and non usage of the noise protective gears. However, it is suggested that loss of hearing ability was higher though not felt by the respondents. Other studies have also reported the health hazards risks of exposure to noise for long time (Bluhm et al., 2004; Ohrstrom, 2004; Bogoch et al., 2005). Teaching and health awareness workshops may help in better understanding and motivation of the drivers on the impacts of noise pollution. This study also revealed that daladala and taxi drivers do not use any noise protective gears due to their non availability and lack of awareness. Thus it is suggested that not only should the protective gears be made available, but also periodic awareness workshops be carried out to motivate the drivers and other vulnerable groups to traffic noise pollution problem. The effectiveness of the noise protective gears over other methods to reduce noise exposure should also be demonstrated. 5. Conclusion This study shows that there is little knowledge of noise pollution problem among commuter bus and taxi drivers in Morogoro Municipality. Despite there log hour exposure on traffic noise, most drivers are less aware of the possible impacts of noise possibly because of their ignorance. Most of the respondents indicated that their hearing quality of were above average and the can hear without difficulty on phones or in crowd. Also the majority of the respondents indicated that they don t use and had never used any kind of noise protective gears because they are not available. Therefore, these results suggest that noise pollution in an acoustic environment affects either directly or indirectly the hearing quality. Further study is needed on the influence of noise on the driver s performance, cardiovascular disturbances, and negative social behaviour and annoyance reactions. 6. Acknowledgment The authors gratefully acknowledge the cooperation and helping hands of the commuter bus and taxi drivers who willingly took part in this study. We acknowledge the financial support from Higher Education Loan Board (HELB) through Sokoine University of Agriculture for granting research project fund to the first author. Mr. Kelvin Tido Mwinuka for help in logistics during data collection. 7. References 1. Bluhm G., Nordling E. and Berglind N Road traffic noise and annoyance An increasing environmental health problem. Noise Health, 6, pp Ouis D Annoyance caused by exposure to road traffic noise: An update. Noise Health, 4, pp Ohrstrom E Longitudinal surveys on effects of changes in road traffic noiseannoyance, activity disturbances and psychosocial well being. Journal of The Acoustical Society of America, 115, pp

6 4. Bogoch I.I., House, R.A. and Kudla I Perceptions about hearing protection and noise induced hearing loss of attendees of rock concerts. Canadian Journal of Public Health, 96, pp Pope C.A. and Dockery D.W Health effects of fine particulate air pollution: lines that connect. Journal of the Air & Waste Management Association, 56, pp Janssen N.A., Van Vliet P., Aarts F., Harssema H. and Brunekreef B Assessment of exposure to traffic related air pollution of children attending schools near motorways. Atmospheric Environment, 35, pp Küzli N., Kaiser R., Medina S., Studnicka M., Chanel O., Filliger P., Herry M., Horak F.Jr, Puybonnieux Texier V., Quénel P., Schneider J., Seethaler R., Vergnaud J.C. and Sommer H Public health impact of outdoor and traffic related air pollution: a European assessment. Lancet, 356, pp

Protect your Hearing

Protect your Hearing 3 Your hearing is precious Throughout our lives we are bombarded with a steady stream of sound in schools, at home, at work and out and about. And sometimes these sounds get so loud