NOISE is the wrong sound in the wrong place at the wrong time. However, no matter how much we try, it has always been there and is for sure going to stay with us, whether we like it or not.
Progress has almost always brought us this form of pollution. Even in the early period of Greek and Roman era, history informs us of the nuisance of noisy chariots. Today, there are two types of noise that are prevalent in the environment.
(a) URBAN NOISE: This is by-product of mechanization and civilization.
(b) RURAL NOISE: This is the other. It’s examples include, air rushing through a thick forest. While the urban may have ill effects on human health, the rural noise may indeed be the very panacea for the tired city dweller to relax. Who would’nt like to enjoy the gentle hum of a windmill in a country or a cuckoo singing on a mango tree?
However, in today’s modern cities, with highly reflective concrete buildings, paved streets and roads devoid of sound absorbing trees, shrubs etc., the noise levels are much more than are welcome.
SOURCES OF NOISE: The main sources of noise according to World Health Organization (Who) in developing countries are:
* Transport-road, rail, air and sea
* Social gatherings — marriages, aerial firing, fireworks, bands etc.
* Building and civil works
* Mills and factories, roadside engineering workshop.
* Human activities with special problems e.g., wars (the US invasion of Iraq being the latest example).
EFFECTS OF NOISE ON HEALTH: Noise exposure can lead to
* Hearing impairment
* Annoyance
* Cardiovascular charges
* Sleep disturbances
* Psychological effects
HEARING IMPAIRMENT: Noise effects slowly, unknowingly but it is reversible if noticed in its early stages. Otherwise, if left to grow, it leads to permanent hearing loss and a ringing in the ears, called tinnitus. It commonly occurs after noise exposure and if often becomes permanent. However, it depends on:
* DURATION OF NOISE EXPOSURE: More is the duration of exposure per day for a longer period, more is the damage.
* AGE: Studies have indicated that the most damaging noise can be caused in old age.
* OCCUPATION: The damaging effect of noise upon people who are more prone to hearing impairment are people like the traffic-police staff; rickshaw drivers, shopkeepers, industrial worker (without hearing protection devices). Others include aviation workers like airport staff where workers are exposed to high-grade aviation noise as they work on runways and reside near the runway in their camps. Hence, they are exposed to noise round the clock.
According to an estimate, Karachi’s population includes about one million residents who are employed as shopkeepers or salesmen, who are constantly exposed to average daytime noise of 90dB during any working day.
In a study conducted by G.H. Sheikh of PCSIR, about 82.8 per cent of Karachi’s traffic constables suffer from Noise Induced Hearing Loss (NIHL). Whereas in rickshaw drivers, NIHL was found 33.33 per cent. For people living in and around places like Guru Mandir and Bolton Market, the case of hearing loss is much worse as the noise level here exceeds 110db at peak hours.
There are various percentage contributions of various noise sources.
* Motor Vehicle 55 per cent
* Aircraft 15 per cent
* Voices 12 per cent
* Radio/TV 2 per cent
* Home maintenance 2 per cent
Equipment
* Construction Noise one per cent
* Industrial Noise one per cent
* Other noise six per cent
* Not ascertained eight per cent
The different noisy sounds on Decibel “dB” are as follows
dB: Sound /Noise.
30: Whisper, quite library.
60: Normal conversation, sewing machine, typewriter, dot-matrix computer printer.
90: Truck traffic, shop tools, (eight hours per day is the maximum exposure to protest 90 per cent of people).
100: Chainsaw, Pneumatic drill.
115: Auto-horn, rock concert
140: Jet engine, blast, gun fire (this noise cause pain).
Many experts agree that continual exposure to more than 85dB is dangerous. The longer one is exposed to loud noise the more damaging it may be. Also the closer you are to the source of intense noise, the more damaging it is.
ANNOYANCE: One of the commonest complaints experienced by people is that of irritabilities and stress caused by noise. The main source being the traffic noise, or aviation noise; and industrial noise. However, the degree of annoyance can hardly be measured scientifically. It is infact a non-tangible entity, which can only be judged from human reaction. Perhaps its parameters could be irritability, appreciation, fear anger, frustration, uneasiness, apathy, chaos and confusion.
EFFECTS ON CARDIOVASCULAR SYSTEM AND SLEEP: Noise effects the systemic circulation, such as construction of blood vessels which leads to hypertension (high blood pressure) and other circulatory ailments. Studies have indicated that constant noise exposure leads to clumping of platelets, hence precipitating a heart attack.
After-effects of constant noise exposure on sleep are well researched. Some well-known effects are perceived sleep quality, changes in mood and impairment of performance.
Fatigue, irritability and nagging headaches are commonest complaints of factory workers, traffic cops, rickshaw drivers and shopkeepers. As work efficiency of an individual is directly related to peace and sanity of mind and body, a tired, exhausted body following a sleepless night cannot produce desirable results. One of the most common causes of poor performance in our offices is lack of sleep caused by the noisy neighbours or the playful lads out in the streets, who for some strange reason, like to play cricket all night long, particularly on weekends.
The rising incidence of tinnitus (ringing sound in ears) in cities like Karachi is also related to noise exposure. It is a two edged sword. Noise exposure causes tinnitus that deprives the victim of sleep.
In Karachi and Lahore, and even in smaller cities, it is common experience that if you are caught unaware by a speeding van, its sudden blast of his pressure horn could make your heart miss a beat, if not precipitate your masked angina. Traffic cops are known victims of hypertension and other cardiac ailments in these cities.
Aviation noise is constantly affecting the hearing of not only aviation works but also the people living near the vicinity of the airport. In the people, living around Karachi’s international airport, hearing impairments in the population are on the rise due to this aviation noise. The Quaid-e-Azam International Airport sees about 125 landings and take-offs every 24 hours. These include “non-certified” aircraft also which emit a lot of immense noise.
Most airports in developed world close down after 10.00pm. Pakistani airports, as indeed most of the airports in the Middle East, function all night so as to accommodate the needs of the developed countries.
But you know something, noise can be controlled. But the strategy to take care of include:
* Control at source
* Control along the path
* Control at the receiving end.
CONTROL AT SOURCE: No doubt prevention of noise production begins with education, awareness and appropriate use of media in highlighting the effects of noise.
Transport shares a major portion of noise production vehicles, like rickshaw. Rickshaws have got to be banned, or at least compelled to maintain their silencers in order. Horns, hooters and music players should also be banned on vehicles. The recent introduction of the Green Buses is a good addition to Karachi’s weary roads. These CNG powered buses not only bring comfort to community population, they are environmental friendly for air and noise pollution. Such vehicle should be encouraged to control along the path.
CONTROL ALONG THE PATH: It means that the path between the noise production source and the affectee. We are planning new expressways, like the Lyari Expressway. These need to have natural barriers for noise control, like trees, plants and clay mounds. Infact our cities bear a barren look. There are hardly any trees, parks or plantation, which is the most natural and economical way of creating noise barriers.
CONTROL AT RECEIVING END: At the receiving end there is no substitute for ear protection. Unfortunately due to lack of education our noise-exposed workers do not use noise protectors, earplugs or ear-mufflers, which are so simple and effective.
The following steps should be taken to protect ourselves from noise pollution:
* Worldwide, exposure to excessive noise is a major avoidable cause of permanent hearing impairment. Noise detecting meters should be installed at major noisy traffic intersections (as in many other cities of the world) to check if the noise level exceeds the permissible level. Traffic cops will divert the traffic to other less noisy zone to bring the noise level at permissible limit.
* Flyovers should be encouraged for traffic solution as they also decrease the noise level being above the earth level. The population of CNG vehicles in the public sector should be increased.
* The procedure to issue a fitness certificate to public vehicles should be made crystal clear. It has to be devoid of corruption so that no noisy vehicle be permitted to roll on the road claiming the hearing of innocent unaware people.
* Aviation and industrial workers should be provided with hearing protection devices.
* Nocturnal civil aviation operations should be closed.
* Tree plantations along roads should be improved. Recently plantation of mature, grown-up date palms along Shahra-e-Faisal will not only beautify the environment, but will also reduce the noise level by absorbing the noise.
Vision without action is a dream. Action without vision is busy work. Vision with action can change the world.
NOISE is the wrong sound in the wrong place at the wrong time. However, no matter how much we try, it has always been there and is for sure going to stay with us, whether we like it or not.
