BY LASISI ADEDOYIN K.S. ( MNES,MICCON ) RESEARCH AND DEVELOPMENT DEPARTMENT , OFFICE OF ENVIRONMENTAL SERVICES, MINISTRY OF THE ENVIRONMENT.
Is Nigeria a noise factory?
In the beginning, God created the universe then created the moon, the stars and the wild beast of the forest. On the sixth day he created the Nigerian and there was peace. But on the seventh day while God rested the Nigerian invented noise (Enahoro,1996).
In his book How to Be a Nigerian
What is Sound and What is Noise?
Sound is a form of energy that is transmitted by pressure variations which the human ear can detect. When one plays a musical instrument, say a guitar, the vibrating chords set air particles into vibration and generate pressure waves in the air. A person nearby may then hear the sound of the guitar when the pressure waves are perceived by the ear.
Sound can also travel through other media, such as water or steel. Apart from musical instruments, sound can be produced by many other sources - man's vocal cord, a running engine, a vibrating loudspeaker diaphragm, an operating machine tool, and so on..
Sound can become noise. Noise is often defined as unwanted sound. This definition reflects the subjective dimension of a definition of noise but does not take account of the fact that wanted noise can cause adverse effects. If this fact is taken into account, a modified version is:
• Noise is sound with any kind of negative effect on human health and well-being (biological, social, psychological, behavioural and performance outcomes).
Definition of noise
The introductory quote mentions three elements of historical importance for definitions of noise: the physiological and psychological damage noise was seen to incur the “wantedness” or “unwantedness” of noise the physical properties of noise: noise was defined as an electrical signal.
Sound is an environmental factor, and it is relevant to look at human exposure to and effects of noise. The exposure depends on:
• the emission of sound
• how the sound is received by the human body
• the setting for the emission and perception of sound.
The effects of noise exposure consist of what is heard or felt, of auditory and non-auditory effects.
These different waves combine and reach the listener via numerous direct and indirect pathways. The listener’s inner ear contains organs that vibrate in response to these molecular disturbances, converting the vibrations into changing electrical potentials that are sensed by the brain – allowing the phenomenon of hearing to occur.
The physical qualities of sounds can be described by quantitative values.
Characteristics of noise
The characteristics of sound are:
• the sound intensity;
• the frequency of the sound; and
• the periodicity and duration: constant, intermittent, sudden and during day or night, also called time history.
The sound intensity refers to the rate of flow of sound energy per unit area in a specified direction; it therefore measures not only sound pressure but also molecular air particle velocity, including direction. Intensity is a vector quantity.
The frequency of the sound is defined in terms of the number of wave cycles that occur during one second; the unit used for describing frequency is the hertz .
The physical quantity of sound pressure level is experienced as the loudness of sound and is expressed in decibels (dB) on a logarithmic scale. The A weighted sound pressure level is used to approximate perception of noise by the human ear. “A-weighting is a standard frequency weighting that deemphasizes low-frequency sound similar to average human hearing response and approximates loudness and annoyance of noise. A-weighted sound pressure levels are frequently reported as dBA.”
Noise is unwanted sound. Usually the sound of a violin is referred to as music – i.e. pleasing. Depending on other factors, the sound may be perceived as noise. Noise perception is subjective. Factors such as the magnitude, characteristics, duration, and time of occurrence may affect one's subjective impression of noise.
Noise: “Unwanted sound-unwanted because it is annoying and or harmful”
Noise : Sound which is undesirable by the recipient”
Types of Noise
(1) Occupational Noise
(2) Community/Environmental Noise
* The World Health Organization calls non-occupational noise community noise. Community noise (also called environmental noise, residential noise or domestic noise) is defined as noise emitted from all sources except noise at the workplace.
What are the common types of Environmental Noise?
In our surroundings, there are different sources emitting various types of environmental noise:
Products intruder alarms of buildings and motor vehicles.
The Hearing Process
Sound funnels into the ear canal and causes the eardrum to move. The eardrum vibrates with sound.
Sound vibrations move through the ossicles to the cochlea.
Sound vibrations cause the fluid in the cochlea to move.
Fluid movement causes the hair cells to bend. Hair cells create neural signals, which are picked up by the auditory nerve. Hair cells at one end of the cochlea send low pitch sound information, and hair cells at the other end send high pitch sound information.
The auditory nerve sends signals to the brain, where they are interpreted as sounds.
The World Health Organization (WHO) defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity, and recognizes the enjoyment of the highest attainable standard of health as one of the fundamental rights of every human being. Environmental noise is a threat to public health, having negative impacts on human health and well-being.
Noise levels are measured in decibels (dB). One decibel is the threshold of hearing. Approximately 60 dB is the level of normal talking. Exposure for more than six hours a day to sound in excess of 85 dB is potentially hazardous to health. However, most Lagosians are exposed to level above 85 dB for more than six hours
What we have done
“ Living in the centre of Lagos is akin to spending all day in a factory according to a recent study on noise pollution in the capital by Adeola et al 2009. Noise levels can reach 90 decibels by 07.30 am and never drop below 70 decibels. The normally acceptable level set by World health Organization is 35-55 decibels”.
Air Quality, Noise and Weather Monitoring Programme for Ikeja Division – (Annexure 2) ; (Annexure 2A)
No. of samples - 146 samples
Location - 15 different locations representing
High Traffic Areas - 62 samples (6 locations - General Hospital frontage, Oshodi under-bridge, Airport junction, Ojota, Ojodu Berger and Iyana Ipaja Under-bridge.);
Residential Areas – 55 samples (6 locations – Alausa
Industrial Areas – 29 samples (3 locations - Specomill
Junction, WEMABOD Estate and WAPCO frontage).
A general overview of the data obtained is as indicated in Annexure 2 for the various categorized areas. chat.docx , Annexure 2 - Air Quality 2.docx
Environmental and Health Effects of Noise
The WHO has documented seven categories of adverse environmental and health effects of noise pollution on humans.
(1) Hearing Impairment- Hearing is essential for well-being and safety. There is general agreement that exposure to sound levels less than 70 dB does not produce hearing damage, regardless of the duration of exposure. There is also general agreement that exposure for more than 8 hours to sound levels in excess of 85 dB is potentially hazardous; to place this in context, 85 dB is roughly equivalent to the noise of heavy truck traffic on a busy road.
(2) Interference with Spoken Communication- Noise pollution interferes with the ability to comprehend normal speech and may lead to a number of personal disabilities, handicaps, and behavioral changes. These include problems with concentration, fatigue, uncertainty, lack of self confidence, irritation, misunderstandings, decreased working capacity, disturbed interpersonal relationships, and stress reactions.
(3) Sleep Disturbances- Uninterrupted sleep is known to be a prerequisite for good physiologic and mental functioning in healthy individuals. Environmental noise is one of the major causes of disturbed sleep. When sleep disruption becomes chronic, the results are mood changes, decrements in performance, and other long-term effects on health and well-being.
(4) Cardiovascular Disturbances- A growing body of evidence confirms that noise pollution has both temporary and permanent effects on humans (and other mammals) by way of the endocrine and autonomic nervous systems. Acute exposure to noise activates nervous and hormonal responses, leading to temporary increases in blood pressure, heart rate, and vasoconstriction.
(5) Disturbances in Mental Health- Noise pollution is not believed to be a cause of mental illness, but it is assumed to accelerate and intensify the development of latent mental disorders. Noise pollution may cause or contribute to the following adverse effects: anxiety, stress, nervousness, nausea, headache, emotional instability, argumentativeness, sexual impotence, changes in mood, increase in social conflicts, neurosis, hysteria, and psychosis.
(6) Impaired Task Performance- Noise pollution impairs task performance at school and at work, increases errors, and decreases motivation. Reading attention, problem solving, and memory are most strongly affected by noise.
(7) Negative Social Behavior and Annoyance Reactions- Social and behavioral effects of noise exposure are complex, subtle, and indirect. These effects include changes in everyday behavior (eg, closing windows and doors to eliminate outside noises; avoiding the use of balconies, patios and yards; and turning up the volume of radios and television sets); changes in social behavior (eg, aggressiveness, unfriendliness, nonparticipation, or disengagement); and changes in social indicators (eg, residential mobility, hospital admissions, drug consumption, and accident rates); and changes in mood (increased reports of depression).
Case Studies in Nigeria
(a) Noise pollution in workplaces poses serious health risks including that of cardiovascular disturbances and impairment of hearing. The study was to assess the effects of occupational noise on hearing among selected industrial workers in Benin City, Nigeria. Male and female workers (n=150) in sawmills, Food Processing industries and Marketers of recorded music who had been exposed to high levels of occupational noise for between 1-14 years were evaluated. The ambient noise levels in their workplaces was found out to be over 90dB. Also, the air and bone conduction defects for both their left and right ears.
The results showed that noise-induced hearing impairment was present in 100% of the workers exposed for a period of 14 years. By 4-8 years, 100% of sawmill workers had developed hearing impairment. In addition, air-conduction pathway in the right ear was affected more than the left ear.
(b) The noise pollution is a major problem for the quality of life in urban areas. This study was conducted to compare the noise pollution levels at busy roads/road junctions, passengers loading parks, commercial, industrial and residential areas in Ilorin metropolis. A total number of 47-locations were selected within the metropolis.
There is no significant difference (P > 0.05) in noise pollution levels between industrial areas and busy roads/road junctions, busy roads/road junctions and high density areas, busy roads/road junctions and passengers loading parks, busy roads/road junctions and commercial areas, passengers loading parks and high density areas, passengers loading parks and commercial areas and commercial areas and high density areas.
The results show that Industrial areas have the highest noise pollution levels (110.2 dB(A)) followed by busy roads/Road junctions (91.5 dB(A)), Passengers loading parks (87.8 dB(A)) and Commercial areas (84.4 dB(A).
Effect on noise on children
The world of the child is becoming noisier and noisier. Compared with the mid-1950s, environmental noise levels (sources such as road traffic ) have increased substantially, causing higher noise levels during day- and night-time at home, at school and during outdoor and indoor leisure activities.
Noise can adversely affect children. Infants reared in noisy homes manifest lower mastery scores on development tests. The most serious consequences of noise are hearing damage and tinnitus. Noise can also provoke a stress response in children that includes increased heart rate and increased hormone response.
Noise can disrupt sleep and thus hinder needed restoration of the body and brain. Noise can negatively affect children’s learning and language development, can disturb children’s motivation and concentration and can result in reduced memory and in reduced ability to carry out more or less complex tasks.
Three types of possible effect on the foetus from high noise levels during gestation of the mother are relevant:
• hearing impairment, assessed in epidemiological surveys in which the noise exposure of the pregnant mother was the decisive factor with respect to noise load; audiometry was performed when the children reached school age;
• effects associated with birth outcomes: low birth weight, gestational age and growth retardation; and
• abnormalities of the baby originating during pregnancy (teratogenesis).
Four types of adverse noise-induced effects on the pre-term baby have been considered:
• impaired hearing;
• disturbed sleep;
• somatic effects; and
• effects on auditory perception and emotional development.
Preschool children and school children
The following effects on preschool children and schoolchildren have been considered:
• hearing impairment
• effects on sleep
• stress-related somatic effects
• cognitive effects
• vocal nodules.
NEED FOR CERTAINTY IN NOISE LEGISLATION LIMITS SITUATION OR EFFECT 30 dBA Excellent speech intelligibility 55dBA Fairly good speech intelligibility 30 dBA No sleep disturbance (inside bedroom) 35 dBA Hospital room 55dBA Residential areas, outdoor, daytime 45dBA Residential areas,outdoor,nighttime 90 dBA Disco and other ballrooms
The industrially developed countries of Europe and America have responded to the need of making laws against Noise. The UK for example passed the Noise Abatement Act of 1960. the US also passed the Noise Control Act of 1972. in Nigeria, several state have come up with different legislation and edit.
In Nigeria, with the legislation, the common law is enough to deal with the Noise pollution.
This is controlled through the tort of nuisance. Nuisance is popular speech means” any sources of inconvenience or annoyance, but the tort of nuisance has a more restricted scope and not every inconvenience or annoyance is actionable’’(Kodilinye 1992).
Let look at some legal action
The Nigerian Courts have effectively utilized the concept of nuisance to control and regulate neighbourhood noise.
(a) In Abiola and Ijoma the plaintiff and the defendant occupied adjoining premises in a residential area in Surulere. The defendant kept 4000 chicken in his back garden. The plaintiff claimed that excessive noise made by the chicken in early hours of the morning disturbed his sleep .The court cited with approval the dictum of Luxmore J and held that the plaintiff's enjoyment of his property. The court awarded damages to the plaintiff and an injunction restraining further acts of nuisance by the defendant.(1971 2All N.L R. 268.
(b) In England, the position is that church bell ringing can be private nuisance at common law. However, it was doubtful whether church bell cloud ever in practise be a public nuisance. In Soltau v DeHeld the court held that sound of church bells could be constitute a private nuisance, and that in this case the bells in question, having regards to their number, size and proximity to the plaintiff’s residence amounted to private nuisance. The court noted that the bells materially interfered with the ordinary physical comfort of human existence according to plain, sober and simple notion of living. An injunction was granted to stop the bell being rung so as to occasion any nuisance, disturbance and annoyance to the plaintiff and his family residing in their dwelling houses.(1851) 2 sim(N.S) 133
( c ) In Odugbesan v Ogunsanya nuisance was established against the defendant who were trustees of an “Aladura” church, which held services, sometimes between midnight and 5 a.m with ringing bell, and wild shouts as devotees became possessed by the Holy Spirit. (LD/354/64,decided Feb.9 1970)
Four-Pronged Approach to Tackle Noise Problem
The four prongs are as follows :
(a) planning - proactive participation in the planning and policy making process, (b) abatement - formulating abatement strategies and implementation of noise abatement measures, (c) control - control on noise by enforcing of the Noise Control laws, and (d) partnership - promoting partnership with various stakeholders.
(e) use of PEP- - use of PEP
Planning Against Noise
Set back-Prevention is the best cure as far as noise is concerned. If homes are not built next to busy roads, then fewer people will be affected by noise.
Retrofit Noise Barrier Programme The Government announced in November 2000 a new policy to mitigate traffic noise impact of existing excessive noisy roads by way of installing noise barriers where practicable. Some 30 road sections with traffic noise exceeding 70 dB(A) were identified as technically feasible for retrofitting noise barrier. It is estimated that with these noise barrier in place, over 25,000 flats will have noise levels lowered by 1 to 19 decibels; and 70% residents along the concerned roads will have noise lowered to below the 70 dB(A) planning standard.
Don't carry out renovation works between 7 p.m. and 7 a.m. or on Sundays or general holidays; otherwise, obtain a valid Construction Noise Permit from the Environmental Protection Department before carrying out the works.
Don't leave powered tools running idly - switch it off when you are not using it.
Complete the work as quickly as possible - don't let it drag on for months.
Abide by any house rules imposed by the building management in respect of renovation noise such as restriction on working hours.
Public Education and Awareness
Entitled to environmental protection from noise pollution
Should know the laws in their community and who their elected representatives are
Mindful about noise pollution and how it might affect our community
Should research the issue and enlist the support of friends, neighbors and local representatives
In conclusion and in view of protecting the lives of Lagosian, the is an urgent need to come up with an enforceable law on noise pollution in the state.