International Journal of Environmental Monitoring and Analysis
Volume 4, Issue 4, August 2016, Pages: 115-120

Noise from Portable Electric Power Generators in an Institutional Setting: A Neglected Risk Factor

John Oluseye Olamijulo1, 2, *, Godson Rowland Ana1, Oyewale Mayowa Morakinyo1

1Department of Environmental Health Sciences, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria

2Healthy Life for All Foundation, University College Hospital, Ibadan, Nigeria

Email address:

(J. O. Olamijulo)
(G. R. Ana)
(O. M. Morakinyo)

*Corresponding author

To cite this article:

John Oluseye Olamijulo, Godson Rowland Ana, Oyewale Mayowa Morakinyo. Noise from Portable Electric Power Generators in an Institutional Setting: A Neglected Risk Factor. International Journal of Environmental Monitoring and Analysis. Vol. 4, No. 4, 2016, pp. 115-120. doi: 10.11648/j.ijema.20160404.11

Received: July 14, 2015; Accepted: October 9, 2015; Published: August 6, 2016

Abstract: An ideal educational setting should be serene and conducive for both learning and working. However, due to the erratic power supply in Nigeria coupled with increase in number of commercial outfits, there has been an upsurge in the proliferation of portable generators at institutional settings. Studies conducted on noise from portable generators and its effects on human health in institutional environment are sparse. Noise levels from exposure to portable generators and its perceived attendant effects was assessed in this study. Oladele Ajose building (OAB) was purposively selected for this pilot study based on the frequency of generator use and level of commercial activities. A semi structured questionnaire was used to elicit information from staff and students. Noise levels in decibels (dB) was measured in six selected location for eight weeks in the indoor and outdoor environment of the building, using a calibrated AEMC sound meter. Results were compared with WHO guideline limits. Mean noise level in the indoor and outdoor environment was 60.26±8.45dB and 58.15±4.53dB respectively. Reported health problems in the last six months prior the study include ear pains (68%), headache (46%), tiredness (60%) and tinnitus (34%). Occupants of OAB are exposed to noise from electric generator at levels exceeding WHO limit. There is a need to find an alternative way to power generation in institutional settings because of the threat noise from generators poses to the serene and conducive learning environment.

Keywords: Noise Levels, Health Effects, Portable Generators, Ibadan

1. Introduction

Noise is progressively becoming ubiquitous, yet an ignored form of pollution in developed and developing countries [1,2]. Noise pollution is a threat to health and well-being, an environmental stressor and nuisance [3]. It is one of the foremost environmental pollutants that has direct effects on human performance [4]. The continued survival of man is contingent upon the enabling environment where he resides, as disruption in the conducive environment may lead to dysfunction in his health status [5]. Urbanisation, civilisation or industrialisation is majorly characterized with noise pollution. Noise is derived from the Latin word "nausea" implying ‘unwanted sound’ or ‘sound that is loud, unpleasant or unexpected [6].

Electricity, one of the benefits of industrialization has become a major priority for most people as they try to meet their domestic, commercial and industrial needs. The world conventional energy supply in 2004 showed that Africa’s highest supply in descending order of magnitude as follows: South Africa-30,020MW; Egypt-14,250MW; Algeria-6,188MW; Libya-4,710 MW; Morocco-3,592MW and Nigeria-3,500MW. But between 2005 and 2009, power generating capacity in Nigeria oscillated between 2,600MW and 3,000MW [7]. According to the Nigerian Energy Policy report from 2003, it is estimated that the Nigeria population connected to the grid system is short of power supply over 60% of the time. In addition, less than 40% of the population is not connected to the grid [8].

The need for electricity in homes, workplaces and industries is high. Yet, the erratic supply of none or low voltage electricity by Power Holding Company in Nigeria makes it imperative for individuals, companies and factories to generate the needed electricity through portable generators without considering its attendants effects [9,10]. A portable electric power generator is a gasoline or diesel-powered device that provides temporary electrical power up to certain voltage and designed for outdoor use [11]. Portable generators are used very commonly in shops, offices and homes today in order to supply power during power shutdowns [12]. The use of generators in every household in a country like Nigeria because of erratic power supply creates seemingly unbearable noise [2]. The noise may be generated by aerodynamic effects or due to forces that result from combustion process or may result from mechanical excitation by rotating or reciprocating engine components [13].

Noise is described in terms of loudness (intensity) and pitch (frequency) and noise exposure is measured using a logarithmic decibel (dB) scale [14]. The Occupational Safety and Health Administration (OSHA) recommends hearing protection in the workplace if there is exposure to noise greater than 85 dB for eight hours or more because of the potential of permanent hearing loss. Noise, even at levels that are not harmful to hearing, is perceived subconsciously as a danger signal, even during sleep [15]. The body reacts to noise with a fight or flight response, with resultant nervous, hormonal, and vascular changes that have far reaching consequences [16]. Recent studies show that noise is now recognized as a serious health problem in our modern societies [17].Both auditory and non-auditory effects are prevalent among the workers/operators working in a noisy environment. The non-auditory deleterious effects of noise include: annoyance, loss of memory, and sleep disturbances [18]. Annoyance has been reported to lead to stress responses, then symptoms and then illness [19]

Noise pollution interferes with the ability to comprehend normal speech and may lead to a number of personal disabilities, handicaps, and behavioural changes. These include problems with concentration, fatigue, uncertainty, lack of self-confidence, irritation, misunderstandings, decreased working capacity, disturbed interpersonal relationships, and stress reactions. Some of these effects may lead to increased accidents, disruption of communication in the classroom, and impaired academic performance [14,17,20]. It also causes stress, mental health effects and neurobehavioral effects. [19,21,22]. The effects of noise pollution on cognitive task performance have been well-studied. Noise pollution impairs task performance at school and at work, increases errors, and decreases motivation. [23,24]. A noise exposure may thus be extremely disturbing in education when the noise masks auditory information required for the on going activity [25].

The World Health Organization (WHO) permissible noise level in an office environment is between 55-65 dBA, (A-weighted decibels) and exposure for more than six hours a day to sound in excess of 85 dBA is potentially hazardous to health [26]. The legal regime on Noise Pollution in Nigeria can be considered under two main headings. The common law and the policy and statutes but Nigeria does not have specific legislations on noise pollution as is the case in countries like the United States of America and United Kingdom.

The use of generators in institutional settings has led to the disapperance of a scerene and conducive environment for learning and performance. This study therefore, assessed noise levels from portable generators and its perceived attendant effects on occupants of an institutional building.

2. Material and Methods

2.1. Study Area

The study was carried out in the Oladele Ajose building of Faculty of Public Health, University of Ibadan, Nigeria. It was named after the first African Professor of Preventive and Social Medicine, Professor Oladele Ajose. It houses the Departments of Epidemiology Medical Statistics and Environmental Health, Health Promotion and Education, Health Policy and Management, Community Medicine and the Adetokunbo Lucas Public Health library. The building commissioned over two decades ago is divided into the new and old complexes. It is located at about 200m from the main gate of the University College Hospital [27]

2.2. Selection of Locations for Noise Level Assessment

Six locations within the Oladele Ajose building (OAB) were selected by stratified sampling for environmental monitoring. The six locations selected are presented in table 1.

Table 1. Selected locations for noise measurement.

Location Description
ELR Environmental Health unit lecture room
ALP Adetokunbo Lucas Public health library
EME Epidemiology, Medical Statistics and Environmental Health main office
HPR Health Promotion and Education computer room
CMR Community Medicine lecture room
RDL Resident doctors lounge

2.3. Study Design

A cross-sectional survey was used which involved questionnaire administration and determination of environmental noise levels at different time intervals.

2.4. Study Population

This included staff, students and business operators, above 18 years of age who gave informed consent to participate in the study. Fifty participants were randomly selected to participate in this survey.

2.5. Materials and Tools

2.5.1. Survey

A semi-structured self-administered questionnaire that included questions on socio-demographic information, occupational history, hearing status information and perceived health effects associated with exposure to noise was used to elicit information from respondents.

2.5.2. Noise Measurement

Noise levels from electric generators were measured using a factory calibrated AEMC sound meter (SLM), which was set at the slow response mode with A-weighting (A-weighted decibels or dBA). Measurements were conducted three times a day 8am-10am, 12pm-2pm, and 4pm-6pm in the indoor and outdoor environment of the selected locations in the building.

2.6. Statistical Analysis

Data collected were analysed using Statistical Package for Social Sciences (SPSS) version 16 at 5% level of significance. t-test was used to compare the means at the different time interval.

3. Results

3.1. Socio Demographic Information

The mean age of respondents was 35.14±8.84 and ranged from 20 to 54 years. Majority of the respondents 52.0% were females. A large proportion of the respondents (86.0%) had tertiary education, (10.0%) had secondary education while 2 (4%) had primary education. Majority of the respondents were lecturers (24.0%) while others were clerical staffs (17.0) students (18.0%), sales persons (12.0%), doctors (12.0%), laboratory technologist (8.0%) and data analyst (6.0%). A good proportion of the respondents (38.0%) were in the age group 30 – 39. Age group 20 – 29 accounted for 30.0% of the respondents while 26.0% and 6.0% of the respondents were in the age group 40 – 49 and 50 – 59 respectively (see figure 1).

3.2. Occupational History

Majority (80.0%) of respondents had worked more than a year in Ajose building while 68.0% spends more than 8 hours a day at work and only 12.0% spend less than 8 hours a day at work (Table 3).

Table 2. Socio-demographic characteristics.

Variable Options (%)
Sex Male 48.0
  Female 52.0
Religion Christianity 84.0
  Islam 14.0
  Traditional 2.0
Ethnicity Yoruba 82.0
  Hausa 2.0
  Igbo 16.0
Occupation Clerical staffs 17.0
  Data analyst 9.0
  Sales person 12.0
  Lecturers 24.0
  Doctors 12.0
  Laboratory technologist 8.0
  Students 18.0
Educational status Primary 4.0
  Secondary 10.0
  Tertiary 86.0

Table 3. Occupational history.

Variable Options %
How long have you been working here? Less than 6 months 4.0
  Greater than 6 months 16.0
  More than a year 80.0
How many hours a day are you at work? Less than 8 hours 12.0
  8 hours 20.0
  Greater than 8 hours 68.0
Do you wear hearing protection devices at work? Yes 4.0
  No 96.0
Is your workplace noisy? Yes 60.0
  No 40.0
If yes, I want a quieter workplace? Yes 52.0
  No 8.0

Fig. 1. Age group of respondents.

3.3. Hearing Status of Respondents

From the survey (see Table 4), 24.0% of respondents experience difficulty in hearing clearly when at work. 16.0% reported hearing problems with receiving calls over the telephone while 18.0% find themselves asking people to repeat themselves when they talk to them.

Table 4. Hearing status information.

Variable (%)
I find it difficult to hear clearly when at work. 24.0
I have a problem hearing over the telephone 16.0
I find myself asking people to repeat themselves when they talk to me 18.0
In a gathering, I find it difficult to differentiate or pick out a specific voice talking to me. 8.0
I find myself knowingly or unknowingly reading lips when people talk to me. 8.0

3.4. Noise Related Health Problems

Table 5 shows the noise related health problems suffered by respondents. The major complains of the respondents include tinnitus (34.0%), sleeplessness (68.0%), tiredness (60.0%), ear pains (68.0%), headaches (40%) and annoyance (28.0%).

Table 5. Noise related health problems experienced by respondents in the last six months prior to this study.

Health problem (%)
Tinnitus 34.0
Ear pains 68.0
Headaches 46.0
Tiredness 60.0
Sleeplessness 68.0
Annoyance 28.0

3.5. Noise Measurement

The mean noise level for the sampled locations at the different time interval is presented in Table 6a and 6b. The mean indoor and outdoor noise level in all the sampling locations exceeded the WHO guideline limit of 35dB and 55dB respectively.

Table 6a. Noise levels between different locations and period in comparison with the WHO standard.

Selected locations Location of sampling unit Time of sampling Mean noise levels (dB) WHO Standard (dB)
EME   8am-10am 70.10±6.10 35
  Indoor 12pm-2pm 69.90±6.86
    4pm-6pm 65.76±4.96
    8am-10am 71.74±5.66 55
  Outdoor 12pm-2pm 72.90±7.23
    4pm-6pm 68.28±7.46
ALP   8am-10am 53.40±4.25 35
  Indoor 12pm-2pm 57.82±7.63
    4pm-6pm 60.20±6.78
    8am-10am 58.15±4.53 55
  Outdoor 12pm-2pm 61.80±6.12
    4pm-6pm 59.36±7.22
ERL   8am-10am 68.40±5.65 35
  Indoor 12pm-2pm 66.80±5.74
    4pm-6pm 63.69±3.78
    8am-10am 70.66±3.44 55
  Outdoor 12pm-2pm 71.72±6.35
    4pm-6pm 66.47±6.24

Table 6b. Noise levels between different locations and period in comparison with the WHO standard.

Selected locations Location of sampling unit Time of sampling Mean noise levels (dB) WHO Standard (dB)
HPR   8am-10am 73.38±9.08  
  Indoor 12pm-2pm 74.64±8.02 35
    4pm-6pm 75.11±9.51  
    8am-10am 74.26±6.36  
  Outdoor 12pm-2pm 76.18±8.37 55
    4pm-6pm 78.15±7.07  
CMR   8am-10am 72.24±7.81  
  Indoor 12pm-2pm 73.55±6.23 35
    4pm-6pm 74.46±8.12  
    8am-10am 75.44±5.26  
  Outdoor 12pm-2pm 77.62±7.34 55
    4pm-6pm 79.21±7.61  
RDL   8am-10am 63.52±3.24  
  Indoor 12pm-2pm 61.73±6.32 35
    4pm-6pm 60.26±8.45  
    8am-10am 64.54±6.61  
  Outdoor 12pm-2pm 65.61±4.26 55
    4pm-6pm 70.28±6.48  

4. Discussion

The noise level estimates in Ajose building both in the indoor and outdoor environment at the different time interval exceeded the World Health Organization (WHO) limits and most of the respondents spend more than 8 hours a day at work.

The WHO guideline set the maximum noise levels in classrooms and outdoor playgrounds at 35dB and 55dB respectively [28]. The background noise level of 35 dB(A) LAeq in classrooms is based upon the assumption of 55 dB(A) for a typical teacher's voice level at a distance of 1 m, and of the need for a signal to noise ratio of 15 dB [29]. The minimum noise level recorded classroom in this study was 65.76dB and this significantly higher than the WHO guideline limit. A recent study conducted in Ibadan revealed high generator noise level of between 91.2 and 100.5 dB(A) [30].

Noise health effectsare the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance, and sleep disturbance [31, 32, 33, 34]. Our study revealed that the major health problems experienced by respondents six months prior to this study include tinnitus, ear pains, headache, sleeplessness, annoyance among others.

In addition, studies have shown that exposure to noise disturbs sleep proportional to the amount of noise experienced in terms of an increased rate of changes in sleep stages and in number of awakenings [35]. Findings of this study revealed that 68% of the respondents experienced sleeplessness six months prior to the commencement of the study due to exposure to noise at elevated levels.

Elevated noise levels can create stress, increase workplace accident rates, and stimulate aggression and other anti-social behaviours [36]. According to Cohen [37] and Gunn [38] noise has been shown to intrude into individual privacy and also causes annoyance, fear and mild anger. Annoyance as well as negative effects on performance has been shown to increase with increasing sound level, tonal character of the noise and variability of the exposure [39]. Our study showed that a good proportion our respondents usually get annoyed as a result of noise exposure.

The study was limited in that we were not able to conduct audiometric test on respondent to ascertain their hearing status as this would have helped in the linkage of the exposure factor to the health problems experienced by the respondents.

5. Conclusion

Generator noise level and perceived health effects experienced by residents of Oladele Ajose Building were assessed in this study. Findings of this study showed that noise levels in Oladele Ajose building were significantly higher than the WHO permissible limit. Major health problems experienced by participants include ear pains, tinnitus and sleeplessness. There is need for design of proper containment measures which would help in the reduction of the hazards associated with the usage of these machines. In addition, alternative energy sources like biogas, solar power should be harnessed while the use of electric generators in the building should be discouraged.


The authors are grateful to 2009/2010 Master of Public Health Students in the Department of Environmental Health Sciences at the College of Medicine, University of Ibadan and residence of Oladele Ajose Building for their contributions.


  1. Akande TM, and Ologe FE (2001). Awareness of commercial grinding machine operators in Ilorin to Noise induced hearing loss. Tropical J. Health Sci. 8: 28–31.
  2. Aluko E. O. and Nna V. U. (2015). Impact of Noise Pollution on Human Cardiovascular System. International Journal of Tropical Disease and Health, 6 (2): 35-43.
  3. Smith AP and Broadbent DE (1992). Non-auditory Effects of Noise at Work: A Review of the Literature. HSE Contract Research Report No 30, London: HMSO.
  4. Debasish, P and Debasish, B. (2012). Effect of Road Traffic Noise Pollution on Human Work Efficiency in Government Offices, Private Organizations, and Commercial Business Centres in Agartala City Using Fuzzy Expert System: A Case Study. Advances in Fuzzy Systems
  5. Otukong ITO. (2002). Environmental Pollution and Emerging Health Hazard: the Nigerian Scenario. Journal of General Practice, 7 (1), 3-4.
  6. Singh N and Davar SC. (2004). Noise Pollution- Sources, Effects and Control. Journal of Human Ecology 16 (3), 181-187.
  7. Adenikinju, A. Analysis of the cost of infrastructure failures in a developing economy the case of electricity sector in Nigeria. African Economic Research Consortium AERC Research Paper 148, February 2005 Nairobi.
  8. Okoye JK and Achakpa PM (2007). Background Study on Water and Energy Issues in Nigeria to Inform the National Consultative Conference on Dams and Development. The Federal Ministry of Agriculture and Water Resources and Society for Water and Public Health Protection, Abuja, Nigeria.
  9. Adefeso I., Sonibare J., Akeredolu F. and Rabiu A (2012). Environmental Impact of Portable Power Generator on Indoor Air Quality. 2012 International Conference on Environment, Energy and Biotechnology IPCBEE vol. 33 IACSIT Press, Singapore.
  10. Awosusi AO and Akindutire IO (2014). Perceived Health Effects of Environmental Noise Pollution on the Inhabitants of Ado-Ekiti Metropolis. Ekiti State, Nigeria. Journal of Biology, Agriculture and Healthcare 4 (26): 106–113.
  11. Ashmore MR. and Dimitroulopoulou C. (2009). Personal exposure of children to air pollution. Atmospheric Environment, 43: 128-141.
  12. Parvathi K. and Navaneetha GA (2003). "Studies On Control Of Noise From Portable Power Generator" in Martin J. Bunch, V. Madha Suresh and T. Vasantha Kumaran, eds., Proceedings of the Third International Conference on Environment and Health, Chennai, India, 15-17 December, 2003. Chennai: Department of Geography, University of Madras and Faculty of Environmental Studies, York University. Pages 328 – 338.
  13. Heywood JB. (1988). Internal Combustion Engine Fundamentals. New York: McGraw Hill Inc.
  14. NIDCD Fact Sheet: Noise-Induced Hearing Loss. NIH Publication No. 97-4233. Updated April 2007.
  15. Babisch W. Noise and Health. Environ Health Perspect 2005; 113: A14 15.
  16. Muzet A. (2002). The need for a specific noise measurement for population exposed to aircraft noise during night-time. Noise Health; 4: 61-4.
  17. Stansfeld S, Haines M, (2000) Brown B. Noise and health in the urban environment. Rev Environ Health; 15: 43-82.
  18. Van Dijk, F. J. H., Souman, A. M, de Vries, F. F. (1987) Non-auditory effects of noise in industry. VI. A final field study in industry. Int Arch Occup Environ Health; 59: 55–62.
  19. Evans G. W, Lercher P, Meis M, Ising H, Kofler WW. Community noise exposure and stress in children. J Acoust Soc Am. 2001; 109 (3): 1023–1027. doi: 10.1121/1.1340642.
  20. Berglund B, Lindvall T. (Eds.) Community Noise. Archives of the Center for Sensory Research. 1995; 2: 1-195
  21. Lercher P, Evans G. W, Meis M, Kofler W. W. (2002). Ambient neighbourhood noise and children’s mental health. Occup Environ Med; 59 (6): 380–386. doi: 10.1136/oem. 59.6.380.
  22. Belojevic G, Evans G. W, Paunovic K, Jakovljevic B. Traffic noise and executive functioning in urban primary school children: the moderating role of gender. J Environ Psychol. 2012; 32 (4): 337–341.
  23. Evans G. W, Lepore S. J. Non-auditory effects of noise on children; a critical review. Children Environments 1993; 10: 42-72.
  24. Cohen S.: After effects of stress on human performance and social behaviour: A review of research and theory. Psychological Bulletin 1980; 88: 82-108.
  25. Kjellberg, A., Landstrom, U., Tesarz, M., Soderberg, L., Akerlund, E. The effects of nonphysical noise characteristics, ongoing task and noise sensitivity on annoyance and distraction due to noise at work. Journal of Environmental Psychology. 1996; 16, 123-136.
  26. WHO (2001). Occupational and community noise. Geneva, World Health Organization (Fact Sheet No. 258).
  27. Morakinyo OM, Ana GR, Hammed TB, Adejumo M. (2015). Indoor Air Quality and Perceived Health Effects Experienced by Occupants of an Office Complex in a Typical Tertiary Institution in Nigeria. Science Journal of Public Health 3 (4): 552-558. doi: 10.11648/j.sjph.20150304.24
  28.  World Health Organisation. (1999) Guidelines for Community Noise.
  29. Shield, B. M. Dockrell, J. E. (2003). The effects of noise on children at school: A review. J. Building Acoustics. 10 (2), 97 – 106.
  30. Yesufu A. L, Ana G. R. E. E. (2012). Electric Generator Characteristics, Pattern of Use and Non Auditory Health Effects Experienced by Commercial Workers in Agbowo and Ajibode Areas of Ibadan, Nigeria. Review of Global Medicine and Healthcare Research; 3 (2): 159-171.
  31. Goines, L, Hagler, L. (2007) Noise Pollution: A Modern Plague. Southern Medical Journal; 100 (3): 287-293.
  32. Passchier-Vermeer W, Passchier W. F. (2000) "Noise exposure and public health". Environ. Health Perspect.; 108 Suppl 1: 123–31
  33. Rabinowitz, P. (2000) Noise-Induced Hearing Loss. American Family Physician.; 61: 2749-56, 2759-60.
  34. Rosen, S. and Olin, P. Hearing Loss and Coronary Heart Disease, Archives of Otolaryngology, 1965; 82: 236.
  35. Stansfeld S. A, Matheson M. P. (2003) Noise pollution: non-auditory effects on health. Brit MedBull; 68: 243-257.
  36. Kryter, Karl D. (1994). The handbook of hearing and the effects of noise: physiology, psychology, and public health. Boston: Academic Press. ISBN 0-12-427455-2.
  37. Cohen S, Weinstein N. (1981) Non-auditory effects of noise on behavior and health. J Social Issues; 37: 36–70.
  38. Gunn W. J. (1987). The importance of the measurement of annoyance in prediction of effects of aircraft noise on the health and well-being of noise exposed communities. In: Koelaga HS (ed) Developments in Toxicology and Environmental Science. Amsterdam: Elsevier, 1987; 237–55.
  39. Holmberg, K. (1997) Critical noise factors and their relation to annoyance in working environments. Doctoral Thesis. Division of Environment Technology. Lulea, Lulea University of Technology.

Article Tools
Follow on us
Science Publishing Group
NEW YORK, NY 10018
Tel: (001)347-688-8931