Leseprobe
CONTENTS
ACKNOWLEDGMENT
ABSTRACT
1. INTRODUCTION
1.1 SOURCES OF NOISE POLLUTION
1.2 EFFECTSOF NOISE POLLUTION
1.3 OBJECTIVE OF STUDY
1.4 SOUND LEVEL METER
2. LITERATURE REVIEW
3. METHODOLOGY
3.1STUDYAREA
3.2 MEASURING INSTRUMENT
3.3 PARAMETERS USED
3.4 PERIODS AND REGULARITY OF MEASUREMENT
4. DATA COLLECTION
5. ANALYSIS, RESULT AND DISCUSSION
6. CONCLUSION AND RECOMMENDATION
REFERENCES
ACKNOWLEDGMENT
My hearts pulsates with trill for tendering gratitude to those persons who helped me in completion of the Project work . First and foremost, I express my sincere gratitude and indebtedness to (Name of Supervisor) , for allowing me to carry on the present topic “Assessment of Noise Pollution in Ghorahi” and later on for their inspiring guidance, constructive, criticism and valuable suggestion. I am very much thankful to him for his able guidance and pain taking effort in improving my understanding of this project.
I would also like to give a special thanks to our college , HOD of Science , Mr. Ganesh Datta Bhatt for providing all necessary facilities during the course. An assemblage of this nature could never have been attempted without reference to and inspirations from the work of others whose details are mentioned in reference section. I acknowledge my indebtedness to all of them.
At the last, my sincere thanks to my all family and friends who have patiently extended all sorts of help for accomplishing this .
ABSTRACT
Cities and towns of the world are now facing enormous rise of noise pollution problem due to very high population rise, transport congestion and associated commercial and industrial activities. Ghorahi, a district headquarter of Dang. (413 km away from Kathmandu) is one such city where noise pollution is very frequent. In order to assess noise level, noise data were collected from various places of the Ghorahi by sound level meter with a duration of 5minutes/location during specified time like 9 am-10 am, 12 am-1 pm and 4 pm-5 pm. The 8 places where the data were recorded are busy, congested and business area like Damodar Chowk, Sahid Gate, campus Chowk, Government hospital gate, Tulsipur Chowk, Ghorahi Bus Park, maalpot and Hospital road. From the observed data, it is found that sound level lies within the range of 60-105 dB or above in different time at eight places. The high noise level is observed during daytime and low at morning time. The highest noise level value observed is 103.2 dB at campus Chowk and lowest noise level value observed is 60.1 dB at government hospital gate. It was observed from the study that, places with high traffic congestion, narrow roads, heavy constructional activities and poor traffic management areas are more vulnerable to high noise levels.
Keywords: Noise Pollution, Sound Level Meter, Silent Zone, Commercial Zone, Heavy Traffic Zone, Environment
CHAPTER - ONE
1. INTRODUCTION
Sound is the vibration of medium(solid, liquid and gas) that reaches our ears .Where the noise is unwanted or excessive sound. In developing country like NEPAL experience several environmental problems. These environmental problems include air, water and noise pollution. Out of these three, noise pollution is one of a major concern for people residing in urban areas. Generally noise is the sound that is unwanted or disrupts one's quality of life. When there is lot of noise in the environment, it is termed as noise pollution. Sound becomes undesirable when it disturbs the normal activities such as working, sleeping, and during conversations. Noise pollution, in the recent times, has been well recognized as one of the major environmental problem that impacts the quality of life in urban areas across the globe. Because of the rapid increase in industrialization, urbanization and other communication and transport systems, noise pollution has reached to a disturbing level over the years. But according to WHO the permissible sound level in Silent Zone (40-50 dB), Commercial Zone (55-60 dB and), Heavy Traffic Zone (80-85dB). Above this value, sound becomes pollution and called as noise pollution.
The word noise is derived from Latin word —nausea implying unwanted sound or sound that is loud, unpleasant or unexpected . It is one of the most immediate and identifiable environmental problem associated with rapid industrialization, urbanization and population growth. However due to its invisible impacts and associated health problems, people are least concern about noise pollution and ignore its menace. Generally, high exposure to noise level can causes feeling of annoyance and irritation, damage to auditory mechanisms, number of health related effects like physiological disorders, psychological disorders, disturbances of daily activities and performances, hypertension and heart diseases. The most serious health hazards associated with high level of noise exposure is deafness which initially causes temporary hearing problem or deafness while prolonged exposure to high noise level causes permanent hearing loss.
Noise has numerous health effects making noise pollution a public health concern although it has not been well addressed. To name a few those effects include elevated blood pressure, noise- induced hearing, sleep disorder and irritability. In addition, noise pollution also creates decrease in the performance at work and school. Noise is described in terms of loudness (intensity) and pitch (frequency) and noise exposure is measured by a logarithmic decibel (dB).
1.1 SOURCES OF NOISE POLLUTION
Noise disrupts the tranquility of the environment and can affect climate and human health negatively. Among the common sources of noise pollution that contributed directly to climate change are:
(a) Electricity Generating Plant
Electric energy occupies the top grade in energy hierarchy as it finds innumerable uses in homes, industry, agriculture, and defense and of course in some nations, transportation. Electricity power situation is very poor because of erratic power supply. As a result, there is an upsurge in the use of electricity generating plant with its attendant noise pollution on the environment and human health. Most workplaces and homes use generating plants 24 hours in alternative to power supply. The noise from generating plants in Nigeria couples with its accompanying smoke emission to the sky has greatly contributed to the breaking of the ozone layer in the sky.
(b) Vehicular Traffic
Increase in vehicular traffic is also a source of noise pollution around the globe especially in most urban cities around the world. The situation is getting seriously alarming with increase in traffic density on city roads. The emissions of smoke from cars are of great concern to the changes we are currently experiencing in the climate of this country and that of the world in general.
(c) Construction /Industrial Noise:
To meet the demands of the necessity of living, the construction of buildings, highways, and city streets causes a lot of noise. Pneumatic hammers, air compressors, bull dozers, loaders, dump trucks, and pavement breakers are the major sources of noise pollution in construction sites all emit one classes of smoke or another, which are all contributing to the current changes in climate.
(d) Household Noise:
Household equipments such as vacuum cleaners, mixers, television, fans and some kitchen appliances are noisemakers of the house. Though they do not cause too much of problem, their effect of noise emitted on human health cannot be neglected. Furthermore, noise can be generated from neighborhood noise consisting of neighboring apartments and noise within one's own apartment.
1.2 EFFECTS OF NOISE POLLUTION
Physical effect of noise:
Noise of high intensity volume will cause either temporary or permanent damage to our hearing. High volume of sound will give rise to noise induced hearing defects that can be experienced in various situation. Considering the significant variations in human ear sensitivity to noisy environment
Physiological effects:
Noise may cause temporary stress reaction (increasing the heart rate and blood pressure), and produce negative effects on our coordination system. Noise can cause persistent increase in blood pressure after a long term exposure to noise .A Few studies were made on general population comparing the physiological behavior of those in noisy street to those living in Quiet environment. The result shows that an increase in blood pressure in those who live in noisy environment, living in noisy street.
1.3 OBJECTIVE OF STUDY
The main objectives of the present study have been presented as follows.
1) To quantify the level of noise pollution in Ghorahi.
2) To draw the noise profile of 8 places of Ghorahi at various hours of the day.
3) To compare the noise pollution in normal and holidays.
1.4 SOUND LEVEL METER (SLM):
A noise meter also called as sound level meter is prepare to measure exactly and objectively the sound or noise level present in the surroundings. But this meter cannot measure the subjective loudness experienced by human ear. Sound level can be measured into two ‘A’ and ‘C’ weightings. ‘A’ set up the meter to behave in the same manner in the human ear, which raise or reduce amplitude over the frequency range and ‘C’ weighting measures for flat response with no raise or reduce of amplitude over the frequency range.
CHAPTER-TWO
2. LITERATURE REVIEW
There are various type of data related to assessment of noise level in Nepal. The noise level measurement is common practice in many places of various countries. This is the first time that assessment of noise pollution has been carried out in Ghorahi. Before the writing this report, I studied the report done by both national and foreign. So some of the relevant studies which are studied for project work are follows:
The noise level survey carried out in Kathmandu. It shows that the noise level varied from 65.1 dB (A) to 74.5 dB (A) in heavy traffic area and 63.2 dB (A) to72.1 dB (A) in low traffic area of Kathmandu city. The study of Noise level carried out by Nepal Health Research Council & WHO in commercial area of Kathmandu valley shows maximum level of 77 dB(A) at Kupondole and minimum level of 58 dB (A) at Tribhuvan University gate 1. The noise level in Banepa city of Nepal varies from 60.1 dB (A) to 110.2 dB (A). Bus parks and Bus stops had minimum and maximum noise levels were 63.9 dB (A) and 110.2 dB (A). It also concluded that residential tenements also had substantial levels of noise, a minimum of 59.11 dB (A). The noise levels produced by different motor vehicles ranged from 121 to 91.2 dB (A), which were substantial. The study observes motor vehicles as main source in the town. The perception survey indicates high prevalence of headaches, lack of concentration, sleep. Since noise levels lie much above the prescribed limits there is an imminent health risk to the exposed population and the study also suggests control measures to minimize the pollution of noise in Banepa 2. The Noise Level Status in Siddharthanagar Municipality shows the highest level of noise of 81.9 dB(A) at Bus Park and the least level of 54.5 dB(A) at Medical college. Similarly, the low levels of noise at Bhairahawa Multiple campus, Annapurna Tole and Goligarh area are due to their location being away from the highway and being plants around them. These results suggest that main sources of noise in the Municipality are the vehicles running on the roads. Similarly the main sources of noise pollution in Siddharthanagar Municipality was found as the vehicles like Buses, Trucks, Tractors, Motorcycles, Delivery Vans etc. running on the roads and Generators during power cut hours. The bad conditions of roads and drivers’ behavior of using horn unnecessarily added more noise 3. The project work in “Assessment of noise Level in Burdwan Town”. This study revealed the noise level intensity and noise pollution of Burdwan town of west Bengal.
In their study they took 17 different location of town and they divide these locations into three categories like silence, commercial, heavy traffic zone. Using sound level meter, they recorded the noise level of each location by spending 30minutes/location during the time around 6am, 10am, lpm, 4pm and 6pm of a day. Most of monitoring place either belongs to silence or commercial zone. It was found that noise level lies between 64 dB-85 dB. The locations that belong to silence zone had noise level upto 90dB. For commercial area had upto 110 dB. The main reasons of noise are transportation, community and religious activities 4. A studied subjective reaction to road traffic noise of residential areas of Delhi. The survey shows that people living up to a distance of 30 m from road feels too much annoyance due to traffic and residents living at all the floors in multistoried apartments feel similar. The impact of traffic noise is so high that 80% of the residents always keep their doors and windows closed. Traffic is so much annoying that 70% of residents want to live away from road irrespective of the existing facility. This study also suggests that Delhi has high level of Noise pollution. Another such study based on NH-6 (Number 6 National High way of India) near Jalgaon city was carried out. In his study, assessment of hearing loss among school teachers and students exposed to highway traffic noise pollution based on the self-reported hearing status data and audiometric analysis was conducted. About 84% teachers and 92% students have reported hearing difficulty in the questionnaire. In the audiometric testing mild hearing loss (25 to 35 dB) was observed in both the subject groups. The strategies need to be adopted for protection of the teachers/students from the noise exposure was suggested 5. A survey in the cities of State of Maharashtra during Ganesh Festival in the month of Aug 27-Sept 7, 2006 to assess the situation of noise levels in various cities in the state of Maharashtra and found that noise levels were exceeding the permissible limits during the festival period. In Aurangabad city, it was observed that minimum noise level was ranging from 52 to 82.9 dB(A) and maximum level was ranging from 73.2 to 115 dB(A) 6. In 2005-2006 had taken various activities to combat noise pollution. The board had taken major steps to tackle noise and other pollution-related problems during Durgapuja in 2005. To have a clear idea about the increase of ambient noise level in residential areas in the city of Calcutta and other district town during the festivals, the West Bengal Pollution Control Board has undertaken a noise monitoring survey in the year 2005 7. The first noise survey in the world was carried out in New York City in 1929.. After that only a few studies were done in fourties and fifties . Pioneering work in the field of noise measurement, analysis and evaluation in India was done by National physical laboratory, New Delhi in the late fifties.
In 2018, a study of sound levels measured on 200 flights representing six aircraft groups found media noise level of 83.5 dB(A) with levels reaching 110 dB on certain flights, but only 4.5% exceeded the NIOSH recommended 8-hr TWA of 85 dB 8. Noise pollution is displeasing human, animal or machine-created sound that disrupts the activity or balance of human or animal life. Noise can be defined as undesirable sound and erratic; intermittent or statistically random oscillation 9. Ogunsote affirmed that it is an unwanted or damaging sound which interferes with what people are trying to do, or that which has an adverse effect on health and safety. Noise can also be understood as a complex sound, a mixture of many different frequencies or notes not harmonically related 10. Environmental noise pollution as the exposure of people or animals to levels of sound that are annoying, stressful, or damaging to the ears. It posited that loud and frightening sounds are part of nature; only in recent centuries has much of the world become urban, industrial, and chronically noisy. Noise can be transferred either through the air (known as airborne sound/noise) or through solid structures/materials. WHO recommended that noise level greater than 75 dB can bring substantial hearing loss. It is suggested that to be able to hear and understand spoken messages in class room the noise level shouldn’t exceed 35 dB, which should be less than 55 dB for outdoor playground 11.
CHAPTER - THREE
3. METHODOLOGY
3.1 STUDY AREA
The study area is Ghorahi, the district headquarter of Dang. The city is situated at a distance of 413 km from the capital. It is spread over an area of 522.21km.sq.This is the seventh largest city and largest sub-metropolitan city of Nepal lies in Province no.5 in the mid-Western part of Nepal having population 156,164 (CBS2011). Ghorahi is one of fast growing city. It is the largest city of Rapti Zone and surrounded by the Sivalik Hills to the south and Mahabharat range to the north so here a large number of schools, hospitals and residential area are situated. In carrying out the noise level measurements, 8 locations selected for this study. They are shown in below table;
Table 1: List of selected Location
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Figure 1 : location of Dang, Ghorahi, Nepal
3.2 MEASURING INSTRUMENT
The measurement of the sound level was carried out using a noise meter which is a type 1 integrated sound level meter. This instrument is very suitable for environmental noise survey.
The measuring instrument was provided by my previous campus: Mahendra Multiple Campus, Dang where i studied bachelor. The instrument was mounted at a height of 1 .2m above the ground for all the 8 locations for consistency of measurement with the antenna pointing to the sound source. The instrument was set at the A-weighting network and the equivalent noise level which is the constant noise level that expands the same amount of energy over the same period, was measured for the various locations. This measurement process was carried out for the 8 locations at three different times of the day which are: 9.00-10.00am, 12.00-1.00pm and 4.00-5.00pm. The instrument was set at automatic mode to run continuously. This is because the instrument faithfully follows all the fluctuations, stores them in its memory and at the end of the measurement calculates an average as Sound level (LI) = 10 logio (I/Io)
A-weighting is the most commonly used curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level. The sound level meter consists of microphone or receiver, preamplifier, weighting network, amplifier, rectifier and digital LCD display meter.
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Figure 2: Portable digital sound level meter.
3.3 PARAMETER MEASURED
Assessment of noise level or sound pressure level in dB (A) (A- weighted decibels) was carried out using Sound Level Meter (SLM) in different zones of the study area including commercial area, Heavy traffic area and silence area. The sound level meter used, can measure the sound frequency from 300 Hz to 8 kHz and from 40 dB to 130 dB in A-weighted scale at four ranges i.e. 40 to 70 dB (A) for low; 60 to 90 dB (A) for medium; 80 to 110 dB (A) for slightly high andlOO to 130 dB (A) for higher intensity of sound.
3.4. PERIOD AND TIME OF MEASUREMENT
The noise level were measured at 8 different locations of the city covering different zones viz. commercial, traffic and silence zones (educational institutions and nursing homes & hospitals. Average time of 5 minutes was followed for measuring noise levels at each location at different time of the day. The sound level meter was handled at proper orientation to receive the maximum sound intensity at 1.2 m height above the ground. The same procedure was maintained for all the survey points in the city. The noise assessment was conducted during morning (9 to 10 am), noon (12 to 1 pm) and evening (4 to 5 pm) of the day. An appropriate distance and proper orientation of microphone of the sound level meter (SLM) was maintained for each sampling location.
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