CONCEPT OF ENVIRONMENTAL NOISE
Noise is the link between what we hear and what we perceive. It may be described as our subjective interpretation of a sound, particularly when it is undesired. Hence Noise is often considered as any unwanted sound that may adversely affect the health and well-being of individuals or populations.
Environmental noise on the other hand is the summary of noise pollution from external environment, generated by outdoor activities. Environmental noise at low levels is not necessarily harmful; it can also convey a sense of liveliness in an area, and is not then always considered ‘unwanted’. Generally, environmental noise includes loud sounds generated from vehicular movement, annoying tones from mechanical facilities or construction sites, sounds that disturb people when listening to voices or music, and sounds disturbing deep sleep, rest or other indoor activities coming from the outdoor environment.
It has been said that human ears were designed to process naturally occurring sounds, and they are beautifully adapted to handle that task. They are able to detect sounds of intensities that vary across many orders of magnitude, and to meaningfully transmit these signals to our brains. However, they are not well equipped to deal with the high noise levels that are common in Nigeria’s mega cities today, because such loud sounds occur only rarely in nature.
Findings revealed that urban dwellers in Nigeria are exposed to high noise levels (above 70 decibels), with the attendant health implications. It could be established that outdoor noise are the major sources of indoor noise pollution which affects residencies as most of it emanates from outdoor activities such as loud music, traffic noise etc. which filters into the building interiors and consequently affects its occupants. A control of these outdoor activities can comparatively lead to a healthier living condition.
Environmental Noise Sources
When one is passing through an area with a high level of noise pollution, such as a construction site, you might not mind this noise since it is a temporary disturbance that isn’t likely to cause hearing loss, stress or other health issues. But if your home which should be a ‘bastion of peace, quiet and calm’ is in such an area with frequent or pervasive noise pollution, this could be dangerous to your health.
Road traffic noise is probably the most widespread and invasive cause of environmental noise pollution. Traffic noise is a function of traffic volume, composition and speed, road characteristics such as smoothness or roughness. Many people live in areas where outdoor noise from traffic is a nuisance and in some cases can lead to psychological and physical problems. Numerous dwellings are exposed to noise from traffic of more than the acceptable limit value of 55 db. According to WHO, noise from traffic can cause nuisance and result in detrimental health consequences such as headaches, sleeping difficulties, stress, high blood pressure, greater risk of heart disease, and hormonal defects. Noise can affect performance and children’s learning ability and motivation. Noise thus has adverse health effects on people and long-term exposure can lead to actual health problems. (WHO, 2009).
Other sources of environmental noise are；Industrial buildings, commercial buildings, neighbourhood noise, construction site, public places such as open markets, streets, parks etc.
Health Effects of Environmental Noise Pollution
It might be tempting to think that environmental noise is not a serious health issue as it’s not easily noticeable in our day to day life. The conseqent effects are gradually built up. (Noise and Health, 2017). Exposure to prolonged or excessive outdoor noise that filters into building interior has been shown to cause a range of health problems ranging from stress, poor concentration, and productivity losses in the workplace, and fatigue from lack of sleep, to more serious issues such as cardiovascular disease, cognitive impairment, tinnitus and hearing loss (Marvel L. A., Moses E. E. and Longe O. T., 2015)
In 2011 the World Health Organization released a report titled ‘Burden of disease from environmental noise’. This study collated data from various large scale epidemiological studies of environmental noise in Western Europe, collected over a 10-year period. The studies analysed environmental noise from planes, trains and vehicles, as well as other city sources, and then looked at links to health conditions such as cardiovascular disease, sleep disturbance, tinnitus, cognitive impairment in children, and annoyance. The world health organisation team used the information to calculate the disability adjusted life-years, basically the healthy years of life lost to ‘unwanted’ human induced dissonance. Exposure to prolonged or excessive environmental noise that disturbs residents has been shown to cause a range of health problems. The team found that at least one million healthy years of life are lost each year in Europe alone due to environmental noise pollution and this figure does not include noise from industrial workplaces. There is overwhelming evidence that exposure to environmental noise has adverse effect on the health of the population.
It is of interest to note that sound we are unaware of is affecting us the most, particularly, outdoor noise that infiltrate our ears when we are asleep. The human ear is extremely sensitive, and it never rests. Such that even when one is asleep, one’s ears are working, picking up and transmitting sounds that are interpreted by different parts of the brain. It is a permanently open auditory channel. Therefore, although one may not be aware of it, background noises of traffic, aircraft or music coming from a neighbour or generally from the outside are still being processed, and the human body is reacting to them in different ways via the nerves that travel to all parts of the body and the hormones released by the brain. (Bruel, Kjaer, 1986). The most obvious is interrupted sleep, with its consequent effect as tiredness, impaired memory, reduced creativity, impaired judgment and weakened psychomotor skills. (Savale P. A., 2014)
Research has shown that people living near airports or busy roads have a higher incidence of headaches, take more sleeping pills and sedatives, are more prone to minor accidents, and are more likely to seek psychiatric treatment. Continual environmental noise sets off the body’s acute stress response.
In conclusion, the realities of modern life signifies that noise created in our world are not going to suddenly fall silent, we need to recognise that environmental noise pollution is a serious health concern worthy of our attention, and find realistic and sustainable ways to manage and reduce it firstly by restricting movement of trucks in the late hours of the night, loud music from street restaurants and night clubs that disturbs our rest at home. Besides, it’s a call to adopt advanced construction features that could help manage environmental noise in residential houses.