Assessment of noise pollution and population exposure in central ...

Feb-Apr.2012, Vol.2.No.2, 1115-1122

e- ISSN: 2249 –1929

Journal of Chemical, Biological and Physical Sciences An International Peer Review E-3 Journal of Sciences

Available online at www.jcbsc.org Section D: Environmental Sciences CODEN (USA): JCBPAT Research Article

Assessment of noise pollution and population exposure in central areas of Morogoro municipality, Tanzania: Impact of use of portable fuel generators Jovine S. Malago and Stelyus L. Mkoma* Department of Physical Sciences, Faculty of Science, Sokoine University of Agriculture, P.O. Box 3038, Chuo Kikuu, Morogoro, Tanzania Received: 17 March 2012; Revised: 7 April 2012; Accepted: 11 April 2012

ABSTRACT The problem of power consumption in the world, and especially in developing countries, is an issue which still raises many questions. Tanzania and specifically Morogoro region is part of the affected population. This study aimed at assessing noise pollution and population expose in the central areas of Morogoro Municipality. Noise levels were measured by using digital sound level meter when there is use or no use of portable fuel generators. For each sampling point the average population exposed to noise was also estimated. The results show that the measured noise levels in all studied points ranged from 72 dBA to 88.8 dBA with a mean of 79.9 ± 2.3 dBA when generators are in use and from 59 dBA to 76.6 dBA (mean of 67.3 ± 2.5 dBA) when generators are not in use. The area around Saifee colour laboratory had high population exposed to noise level of 77.7 dBA (average 18 people/1 hr). The lowest noise was measured at Mt. Uluguru hotel (72 dBA) and highest at Wildrose hotel (88.8 dBA). The study concludes that use of portable fuel generators increased noise levels in central areas of Morogoro municipality in addition to other urban noise such as vehicle traffic. The observed noise is likely to have adverse health problem in a long term human exposure.

Keywords: Noise pollution, Community exposure, Fuel generators, Survey, Tanzania INTRODUCTION The problem of power consumption in the world, and especially in developing countries, is an issue which still raises many questions. About one third of the electricity production in the world goes to USA, while for developing countries, the percentage are variable depending on the country. Typically higher shares are distributed for non-residential, and grid penetration to rural areas is very low. In reality, a fair amount of energy is lost along the way. Tanzania has faced the problem of power rationing for almost all months of year 2011. Like other regions of the country, Morogoro with an estimated population of (300,000 inhabitants) is supplied with the electric power from national grid which is mainly contributed by hydro electric power. 1115 J. Chem. Bio. Phy. Sci. Sec. A 2012, Vol.2, N0.2, 1115-1122.

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Stelyus L. Mkoma et al.

Morogoro municipality is one of the most important commercial centres in the region which leads to expansion of social services, transport services, power supply and business activities. The residents of Morogoro municipality are mainly employee in the government or private sectors or engaged in small scale to large scale business and urban agriculture1. The presence of shopping centres and market place in the municipality has made an increased demand for electric power. However due to shortage of rainfall since 2005 there is a decrease of production and supply of electric power in the national grid. About 70% of the country electricity comes from hydro-electric power generators and the remaining 30% supplied from diesel/petrol oil and imports from neighboring Uganda and Zambia2. For the past 5 years, like other parts of the country, Morogoro municipality has been facing power cuts/breakdown and as a result most residents especially business men are supplying themselves (in homes, shops and offices) with power from portable diesel/petrol generators. These generators produce high levels of noise, in addition to noxious gaseous emissions. Noise exposure increase the risk of myocardial infarction and total ischemic heart disease, hearing loss, annoyance and irritation, and interferes with sleep, concentration and speech communication3-6. This study therefore aimed at assessing noise pollution in the central areas of the Municipality in Tanzania as an impact of use of portable fuel generators. The population that is possibly being exposed to such urban noise was also investigated.

MATERIALS AND METHODS Study Area: This study was conducted in Morogoro municipality (500-600 m above sea level) and specifically central parts of the town where portable fuel generators act as the source of power in case the supply of electricity goes off. Morogoro municipality is among the fastest growing urban centres in Tanzania located about 200 km west of Dar es Salaam, and lying on the Northern foot slopes of Uluguru Mountains. The municipality is sub-divided into 19 administrative wards and 275 streets and serves as a junction for two major highways to the western, northern, and southern parts of Tanzania, as well as to the neighbouring countries of Malawi, Rwanda and Zambia. Rapid population growth and development have affected many sectors in Morogoro including demand for more energy source2,7. Noise Level Measurements: The noise levels was measured using sound pressure level (dB) meter on weeks of September 2011 at selected places dominated by commercial and residential tenements. This noise survey focused on the busy streets and the most crowded areas in the town centre. The selected areas included the following streets/roads/areas: Madaraka road, Makongolo road, Konga Street, John Mahenge street, Uhuru street, Boma road, Sultan area, Lumumba road and Nunge area. All these streets/roads have its unique characteristics i.e. having typical wholesaler and retailer shops, use generators during power cut and are busy and populated most of the daytime. The noise measurements were carried out at two scenarios: (1) when there is power from the national grid (2) when there is power cut during the daytime period which runs from 7.00 am to 6.00 pm. And for each scenario, noise data was collected three times in different days of the week. The measuring points was selected at a distance of 2 meters from the generators where the passengers are waiting to purchase items in shops or passing by the street if not doing other activities near measurement points. The number of these people passing and/or present at measurement point was estimated in order to have idea of possible population that can be at immediate risk of noise pollution. The following measurements all expressed in dB were recorded: 1. Maximum sound pressure level (peak noise) – the noise with the maximum intensity (Lmax) within each 5-minutes period. 2. Minimum sound pressure level (baseline noise) – the noise with the minimum intensity (Lmin) within each 5-minutes period.

1116 J. Chem. Bio. Phy. Sci. Sec. D, 2012, Vol.2, No.2,1115-1122.

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3. A-weighted equivalent continuous level (LAeq) (Average) – if one listened to this level of noise constantly for 5 minutes; the ears would be exposed to the same amount of noise as if listened to the varying level of noise recorded in each 5-minutes period.

RESULTS AND DISCUSSION Environmental noise: The noise measurements in the current study were taken in the time when people use generators to supply themselves with electric power and time when generators are not used (use the national grid power supply). The results showed that noise levels are high in both cases with small differences between measurement points. The measured noise levels in all studied sites ranged from 72 dBA at mount Uluguru hotel to 88.8 dBA at Wildrose hotel (with a mean of 79.9 ± 2.3 dBA), when generators are used and from 59 dBA at Chadema office to 76.6 dBA at barber shop (Lenox) (with a mean of 67.3 ± 2.5 dBA) when generators are not used (Table 1 and 2). Table-1: Mean, median and ranges of noise levels when fuel generators are used in central areas of Morogoro municipality. Measurement site

Madaraka road Machare hard ware Cosmetics for way Makongolo road Saifee color laboratory Kibo vet center Kingo ward Chadema office Top life grocery Maco entertainment John Mahenge street Sophia hotel Mulard’s super grocery Boma road Mount Uluguru hotel Fakhri hardware Sultan area Double A NMB Wami branch msikitini Burhan comp. point Lumumba road Masika barber shop High classic hotel Airtel office Nunge area J.phone Wildrose hotel

Noise levels (dBA) Median Minimum

Mean LAeq

Std. Dev

77.3 80.4

2.9 0.0

75.8 80.4

74.1 79.1

81.8 82.5

77.7 79.8

2.1 2.3

77.1 79.8

77.0 78.9

81.5 82.9

77.3 77.7 76.5

1.4 5.0 3.0

77.3 77.1 76.9

76.8 77.1 75.5

80.3 81.2 81.2

79.9 84.1

0.9 2.7

80.1 82.7

79.5 83.0

81.9 87.0

72.0 83.4

2.7 2.2

72.9 84.5

73.1 83.1

75.2 85.9

79.7 74.5 74.6 82.8

1.7 2.6 2.7 1.8

80.3 74.4 75.2 83.0

78.2 74.3 74.1 81.9

83.9 77.2 79.3 85.4

81.4 81.5 81.8

1.3 3.2 0.8

81.5 82.1 81.8

79.6 80.2 76.0

83.1 84.1 82.1

83.1 88.8

6.0 0.9

83.1 89.3

83.3 88.7

89.5 90.0


Maximum

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Table-2: Mean, median and ranges of noise levels when fuel generators are not used in central areas of Morogoro municipality. Measurement site

Madaraka road Machare hard ware Cosmetics for way Makongolo road Saifee color laboratory Kibo vet center Kingo ward Chadema office Top life grocery Maco entertainment John Mahenge street Sophia hotel Mulard’s super grocery Boma road Mount Uluguru hotel Fakhri hardware Sultan area Double A NMB Wami branch msikitini Burhan comp. point Lumumba road Masika barber shop High classic hotel Airtel office Nunge area J.phone Wildrose hotel

Noise levels (dBA) Mean LAeq Std. Dev

Median

Minimum

Maximum

68.4 73.9

1.9 2.2

69.0 73.9

66.9 70.3

74.0 80.0

64.2 66.7

1.9 0.5

63.3 66.7

63.1 65.6

75.1 74.8

59.1 62.5

4.2 3.8

56.7 62.0

56.8 58.9

68.3 68.7

68.3

1.8

68.0

64.0

73.0

60.2 73.8

2.0 0.8

60.6 73.4

57.7 70.9

67.5 77.9

67.7 68.5

2.9 5.4

66.5 66.6

64.2 64.7

70.5 73.3

64.8 62.5 67.9 68.4

2.3 1.8 2.3 1.7

65.5 62.2 67.0 68.0

61.9 57.8 65.0 64.4

70.1 70.6 73.9 75.1

76.6 66.9 70.9

4.5 0.5 3.7

77.0 67.0 72.4

67.7 65.9 67.5

82.9 74.5 74.7

68.3 68.1

3.3 1.1

68.3 68.0

65.8 67.2

74.5 73.1

In the two scenarios, the mean noise levels were above standard limit recommended by Tanzania Bureau of Standards (TBS)8 and the World Health Organisation (WHO)9 of 55 dBA to areas of mixed residential with some commercial and entertainment. It is suggested that the high environmental noise when generators are not used was mainly caused by noise from road traffic and motor cycles, the music systems which are run in most electronics selling shops. On the other hand, when compared these results to other studies done on noise pollution in restaurants in Morogoro municipality as reported by Samagwa et al.10, the noise levels in restaurants are lower than those from this study. But higher levels than those observed in the current study were reported by Kweka and Young11 in survey of noise levels in wood workshops in Morogoro municipality. Figure 1 shows that there is variation of noise levels between sampling points, with higher noise levels when fuel generators are in use than when they are not in use. The variations in noise levels may also be caused by use of generators of different brands, size, quality and age. However, differences in source 1118 J. Chem. Bio. Phy. Sci. Sec. D, 2012, Vol.2, No.2,1115-1122.

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strength of urban noise sources could also contribute to the differences in noise levels between sampling points. 100 Generator in use

Generator not in use

Noise level (dBA)

90 80 70 60 50

WID

JPH

AIR

HCH

BAB

BUH

MSK

NMB

DOB

FAH

ULU

MUL

SOH

MAC

TOP

CHD

KBO

SCL

CFW

MAH

40

Sampling points

Figure-1: Trends of noise levels at different measurement points for the period with and without fuel generator in use. Abbreviation: MAH–Machare hardware; CFW–Cosmetics for way; SCL–Saifee color laboratory; KBO– Kibo veterinary center; CHD–Chadema office; TOP–Top life grocery; MAC–Maco entertainment; MUL–Mulard’s super grocery; ULU–Mt Uluguru hotel; FAH–Fakhri hardware; DOB–Double A; NMB– National Microfinance Bank-Wami branch; MSK–Msikitini; BUH–Burhan shop; BAB–Barber shop; HCH–High classic hotel; AIR–Airtel office; JPH–J. phone) and WID–Wildrose hotel. It can be observed in Table 3 that Nunge area had highest noise level (86.77 ± 3.5 dBA) and Kingo ward having the lowest (77.2 ± 3.1 dBA) when generators were used whereas when generators were not used the highest noise level was found in Lumumba road (71.5 ± 2.9 dBA) and Kingo ward having the lowest level (63.3 ± 3.3 dBA). It is suggested that the observed high noise levels were from fuel generators in addition to other urban sources such as road traffic. Table-3: Mean and associated standard deviation of noise levels (dBA) in surveyed roads/street/areas in Morogoro municipality. Street/road/areas

Fuel generators in use Mean LAeq Std. Dev

Fuel generators not in use Mean LAeq Std. Dev

Boma road

77.7

2.5

68.1

4.2

Lumumba road

81.6

1.8

71.5

2.9

Madaraka road

78.9

1.45

71.2

2.1

Makongolo road

78.8

2.2

65.5

1.2

John Mahenge street

82.0

1.8

67.0

1.4

Kingo ward

77.2

3.1

63.3

3.3

Nunge area

86.0

3.5

68.2

2.2

Sultan area

77.9

2.2

65.9

2.0


Assessment.....


Based on relative frequency distribution of noise level (dBA) at central areas in Morogoro Municipality, it was observed that less than 20 percent of noise level was found between 55 and 60 dBA when generators were not used and none when generators were in use. About 70% of noise levels were found above 60 and below 70 dBA when generators were not used and less than 10% when generators were used. It was also observed that less than 40% of noise levels when generators were not used and more than 80% of noise levels when generators were used were found above 70 dBA (Figure 2). 100 Frequency distrib. (%))

Generators not in use

Generators in use

80 60 40 20 0 >556070

Noise level (dBA)

Figure-2: Relative frequency distribution of noise level (dBA) at central areas in Morogoro Municipality. Population exposure: Figure 3 shows average population exposed to noise for about 1 hour in the surveyed sites. Saifee color laboratory had large number of people exposed to noise (mean, 77.7 dBA), that is 18 people (35% population counted) staying in the area and about 33 people passing by the area for 1 hour. As it was for Seifee color laboratory, 18 people were exposed to noise ranging from 57.8 to 77.2 dBA for about 1 hr was at National Microfinance Bank Wami branch, but with nearly 100 people passing by the areas.

Average people at site/1 hr-

20

15

10

5

MSK

WID

JPH

AIR

HCH

BAB

NMB

DOB

FAH

ULU

MUL

SOH

TOP

CHD

MAC

KBO

SCL

CFW

MAH

0

Sampling points

Figure-3: Population exposure to noise of Morogoro residents at different measurement sites during the study period (See Figure 1 for abbreviations).


Assessment.....


The least number of exposed people was at Mt. Uluguru hotel and Cosmetics for way. These areas had on average 3 people staying in the area and about 30 people passing by the area for 1 hr, which is equivalent to 5% of the estimated population. It should be noted that Mt. Uluguru hotel had lowest noise level of 72 dBA (Table 1) for the time when fuel generator is in use. On the other hand, highest measured noise levels was at Wildrose hotel (mean, 88.8 dBA) that had on average 7 people that are exposed that noise for 1 hr including about 30 people passing by the area. In conclusion, it is estimated that on average 8 people in surveyed sites are exposed to urban noise above TBS8 and WHO9 limit levels for areas of mixed residential with some commercial and entertainment. Hence, the exposed population is likely to have adverse health problems associated with long term exposure to noise if control measures are not taken into account. CONCLUSION The noise levels were measured using sound pressure level (dBA) meter on weeks of September 2011 at selected places dominated by commercial and residential tenements. The noise survey focused on busy sites and most crowded areas in the central area of Morogoro municipality. The results showed somewhat low noise levels when regular electricity from the national grid is in use than when using fuel generators. The study showed that the use of portable fuel generators during power breakdown was one among the main source for high environmental noise in central areas of Morogoro municipality. It is also suggested that on long term exposure the general population is likely to face health problems related to noise such as noise-induced hearing loss, impairment of task performance, social behaviour and annoyance reactions, cardiovascular disturbances and sleep disturbances. Raising awareness among the public community on impacts of noise, reinforcement of environmental laws and regulations and providing continuous monitoring of noise levels are issues that need to be given attention.

ACKNOWLEDGMENT We acknowledge the financial support from Tanzania Higher Education Students' Loans Board (HESLB) and Sokoine University of Agriculture for granting special research fund to the first author. We are also gratefully to the cooperation of shops/hotel owners who willingly allowed us took noise measurements at their business sites.

REFERENCES 1.

Tanzania Government, Municipal Planning Department Report, Morogoro, Tanzania, 2007.

2.

B.M. Lyimo, Sustainable Energy Watch report. HELIO International /Tanzania, 2002.

3.

P.C. Eleftheriou, Applied Acoustics, 2002, 63, 5.

4.

E. Kempen, H. Kruize, C. Boshuizen, B. Ameling, M. Staarse and M. Hollander, Environmental Health Perspectives, 2002, 110, 307.

5.

B. Jakovljevic, G. Belojevic, K. Pavnovic and V. Stojanov, Croatian Medical Journal, 2006, 47(1), 125.

6.

F. Nejadkoorki, E. Yousefi and F. Naseri, Iranian Journal of Environmental Health Science & Engineering, 2009, 1, 53.

7.

United Republic of Tanzania, URT, Women and Men in Tanzania. Bureau of Statistics: Dar es Salaam, 2002.

8.

Tanzania Bureau of Standards, (TBS). National Environmental Standards Compendium EMDC 6(1733). P2: ACOUSTICS - General Tolerance Limits for Environmental Noise, 2005.

9.

World Health Organization (WHO), Guidelines for Community Noise, edited by Birgitta Berglund, Thomas Lindvall, Dietrich H Schwela. Geneva, 1999. 1121 J. Chem. Bio. Phy. Sci. Sec. D, 2012, Vol.2, No.2,1115-1122.

Assessment..... 10.


D. Samagwa, S.L. Mkoma and C. Tungaraza, Journal of Applied Sciences and Environmental Management, 2009, 13(4), 29.

11.

A.E. Kweka and Z. Young, Tanzania Journal of Forestry and Nature Conservation, 2009, 79(1), 69. ,

*Correspondence Author: Stelyus L. Mkoma; Department of Physical Sciences, Faculty of Science, Sokoine University of Agriculture, P.O. Box 3038, Chuo Kikuu, Morogoro, Tanzania
