Urban Noise Pollution: Causes, Effects, and Solutions
As societies become increasingly industrialised and urbanised, Noise Pollution, also known as Sound Pollution, has emerged as a significant environmental issue. Noise pollution can be considered one of the main agents of loss of environmental and life quality in a metropolis and its dissemination pushed the boundaries of industrial facilities, spreading through the streets and also for leisure activities, moments of rest and work. The traditional definition of noise is “unwanted or disturbing sound”. Since 1972, the World Health Organization (WHO) has declared noise as a pollutant. Over the last decades, the quality of the urban environment has attracted the interest of researchers due to the growing urban sprawl, especially in developing countries. Urban noise can be considered one of the main sources of pollution. Nowadays, acoustical environmental quality in urban areas is threatened.
The urban environment is composed of several audible sources: Traffic (road, rail, and air), industrial facilities, civil construction and social activities (parties, fairs and open air markets, and residential noise). Cities have many sources of noise; many of the more significant and preventable sources arise from traffic and industry. In rural areas, farm machines and pump sets are the main sources of noise pollution. Construction activities, such as drilling, hammering, and heavy machinery use, also add to the noise levels.
This paper presents an evaluation of soundscape, bearing in mind that sensations and perceptions may differ depending on the activity performed, even considering individual and subjective questions. Thus, we selected three different daily activities: Leisure, work, and rest, under the influence of noise sources. The study was conducted in the city of Porto, which is the second-largest city of Portugal, with an area of 41.66 km2 and a population of 237,000 inhabitants.
Example of a noise map in an urban area.
Measuring and Understanding Noise
Because noise is measured using a logarithmic scale, a 3 dB(A) change in noise, a level which is generally noticeable, corresponds to a doubling in the power of the generated noise. Measures of noise exposure integrate sound power over a period of time. The instantaneous maximum or peak values Lmax is a measure used for equipment regulation but not typically used as a measure of human exposure.
Schafer introduced the concept of soundscape as a scope to thinking beyond the noise levels, considering human experience in the environment and its cultural dimension. Soundscape research means to focus on the meaning of sounds and its implicit assessments, and understanding perceptual effects. The effects of exposure to noise on the human organism are subject to the specific characteristics of the noise, such as frequency, intensity, and exposure time, and also individual susceptibility.
Health Impacts of Noise Pollution
Chronic exposure to elevated levels of community noise creates significant health risks. These health impacts of noise depend on the intensity of noise, on the duration of exposure, and the context of exposure. Noise is a biological stressor; it triggers autonomic chemical mechanisms for arousal and alertness.
Noise interferes with sleep. Noise can make it difficult to fall asleep, and abrupt noises can cause awakenings, which the sleeper may not sense or recall. Even at levels below which awakening may occur, noise produces measurable physiological reactions, such as increase in heart rate and body movements and can cause disturbances of natural sleep patterns by causing shifts from deep to lighter stages. Sleep disturbance can begin at relatively modest noise levels (40 dB). At the level of noise produced by a busy road, the proportion affected by sleep disturbance becomes significant. Average nighttime noise level of 65 dB will result in self-reported disturbance of sleep in about 15% percent of the population.
A cross-sectional study was conducted from March to May 2012 to evaluate the perception and annoyance in the urban soundscapes: During the leisure time, at home, and at work in different exposures (noise levels). The study population consisted of adult individuals older than 20 years old who agreed to answer a questionnaire. One hundred and eighty individuals were interviewed, 60 in each of the three defined scenarios. The interviewees’ average age was 52-years-old (IC95%: 49.54-54.49). Demographic characteristics, perception of noise sources, annoyance and other effects caused by exposure to noise, and perception of environmental problems according to the interviewees in each urban soundscape (leisure, work and home).
Considering the perception of noise sources in the different urban soundscapes, including noise by highway, railway, and air transport and neighborhood noise, 70% of the individuals reported noticing some source of noise in the selected scenarios. With regard to the annoyance caused by the urban noise in all urban soundscapes, 41.7% mentioned feeling some degree of annoyance and, among them, 16.7% felt highly annoyed. The majority of the interviewees considered noise as an environmental problem (88%) and believed that noise exposure can cause or aggravate health conditions [84%, Table 2].
An ordinal logistic regression was performed to identify factors associated with annoyance, adjusted by the following variables: Gender, age, and education. It was observed that in the work scenario the chance of reporting significant annoyance was tripled when compared with the leisure scenario (OR: 3.51; IC95%: 1.31-9.39), while in the home scenario, this chance was the quadruple of that of the leisure scenario (OR: 8.40; IC95%: 3.04-23.19).
Solutions for Mitigating Noise Pollution
Thoughtful planning and building rules and their strict enforcement can mitigate many noise conflicts. Zoning codes can limit the incompatible proximal location of residential and commercial uses. Enforcement of all noise laws is variable and often subjective. Municipalities can purchase quieter public service and transit vehicles (e.g. electric and hybrid buses). Cities can adopt building standards to require quiet interiors (e.g. Subsidize acoustical retrofits (e.g.
At the national level, regulations limit the allowable sound levels produces by aircraft, railway and roadway vehicles and certain heavy equipment. For example, almost all aircraft in current operation must meet standards for runway takeoffs, landings, and sidelines, which depend on the aircraft's weight and its number of engines. However, noise may substantially increase for residents living near a newly planned airport. Furthermore, emissions standards do not address the problem of cumulative emissions.
| Scenario | Exposed Area | Non-Exposed Area |
|---|---|---|
| Leisure | Quinta do Covelo | Parque da Cidade |
| Work | Streets: 31 de janeiro, Sá da Bandeira and Passos Manuel | Santa Catarina Street |
| Home | Outeiro neighborhood | Carriçal neighborhood |
In 2002, the European Union adopted the Directive 2002/49/CE20[8] regarding the assessment and management of environmental noise, with the goal of controlling and reducing sound pollution using a common approach and avoiding or preventing the harmful effects of noise exposure. The EU established the enforcement of developing strategic noise maps that should estimate the exposure to outside ambient noise, based on assessment methods in agreement to the EU levels.
The pervasive noise pollution can be controlled only through cooperation between all the stakeholders, i.e. individuals, families, society and the Government. Restricting the use of loudspeakers and amplifiers.
Noise pollution control strategies.
Noise Pollution is a growing concern with significant implications for health, environment, and quality of life. Addressing this issue requires a multifaceted approach involving regulatory measures, technological innovations, and public awareness.