"The city of noise"

Collab: Carolina Somoza, B.A. in Political Science (University of Buenos Aires), holds diplomas in Environmental Law, the Rights of Migrants and Refugees, and Comprehensive Environmental Education. Teacher and serves as an advisor at the Office of the Ombudsperson (Autonomous City of Buenos Aires).

Whether you are at home (especially if you live in a busy area) or simply step outside there it is: the bus stopping half a block away the motorcycle roaring past without a muffler the drill from the building going up next door the siren cutting into your conversation when you sit down for coffee. We have become so immersed in this constant background noise that we no longer perceive it as a problem. Yet noise pollution is neither a minor nuisance nor a matter of personal preference: it is an environmental pollutant with a direct impact on human health as recognized by the World Health Organization and cities (especially large ones such as Buenos Aires) are among its main sources.

An invisible pollutant: from an environmental perspective not every sound constitutes pollution. The problem arises when noise is excessive continuous or inappropriate and causes disturbance or harm. It is measured in decibels (dB) a logarithmic scale: every 10 dB increase corresponds in terms of perception to a doubling of sound intensity. This explains why the difference between a quiet street and an avenue with heavy traffic can feel so significant even when the numerical difference may appear small. In 2018 the WHO published its Environmental Noise Guidelines for the European Region which currently serve as an international reference. For road traffic it recommends not exceeding an average of 53 dB over the course of the day measured as Lden an indicator that takes daytime evening and nighttime noise into account and 45 dB at night the level above which measurable effects on sleep begin to occur. These are recommendations not mandatory limits but they are based on hundreds of epidemiological studies.

What happens when these thresholds are consistently exceeded? Accumulated evidence associates chronic exposure to urban noise with hypertension an increased risk of heart attack and stroke sleep disorders stress Irritability and learning difficulties in children. Noise pollution does not affect humans alone. It also profoundly alters the behavior of numerous animal species. For example:

• Birds rely on their songs to attract mates defend their territories and warn of the presence of predators. When traffic noise interferes with these signals many species change the time of day when they sing, raise the pitch of their vocalizations or simply abandon certain urban areas.

• Marine mammals represent one of the best-known cases. Whales and dolphins use sound to navigate communicate and locate food. Increasing maritime traffic seismic surveys and other human activities create an acoustic environment that makes these processes which are essential to their survival more difficult.

• Amphibians also experience alterations in their reproductive calls while some bats face greater difficulties using echolocation to hunt insects at night.

There is therefore increasing evidence that noise can modify entire food chains and alter the functioning of ecosystems. It is not simply a nuisance: it constitutes an environmental pressure factor affecting biodiversity.

Buses and motorcycles noise on the move: transportation is in almost every city in the world the dominant source of noise pollution and the Autonomous City of Buenos Aires is no exception. Buses contribute low-frequency sustained engine noise aggravated by the condition of the vehicles the use of horns and the constant braking associated with traffic in Buenos Aires. Motorcycles on the other hand generate sharper and more irregular peaks (often due to modified exhaust systems or simply the absence of an exhaust system) which are perceived as more disturbing even when they last for a shorter period of time. Since 2004 the City has had specific legislation in place: Law N° 1540 on Noise Pollution Control regulated by Decree 740/07 it establishes noise-emission limits according to area time of day and type of source and designates the Environmental Protection Agency (APrA) as the enforcement authority. The law applies both to fixed sources such as businesses construction sites and industries and mobile sources including vehicles motorcycles and freight transportation. It also authorizes controls on public roads often through joint operations with the police. The problem is not so much the legal framework as the actual capacity for enforcement over a vehicle fleet that continues to grow.

Construction noise with a schedule (that is not always respected): Construction is another major fixed source of noise and the one that generates the most complaints from residents. Regulations in the Autonomous City of Buenos Aires establish time periods during which construction activities that produce excessive noise are prohibited with the aim of protecting nighttime rest and weekends. However between demand for new real estate development and the limited number of inspectors effective enforcement often ends up depending on complaints from residents: in the case of repeated violations people can contact APrA the local police station or the City Prosecutor's Office if the situation constitutes a contravention.

One fact helps put the problem into perspective: the Autonomous City of Buenos Aires has developed a noise map a tool designed primarily for road and railway traffic which still does not systematically incorporate construction noise. This type of noise is usually more localized but can be equally invasive for those living next door.

Thinking about quieter cities: Reducing noise pollution does not mean eliminating urban life or striving for absolute silence. It means designing cities in which well-being is also an environmental objective.

• Urban planning can play a fundamental role through the incorporation of noise barriers road surfaces that reduce traffic noise land-use planning and a better distribution of potentially noisy activities.

• Green spaces also play an important role. Although they do not completely eliminate noise they help reduce it while at the same time creating environments perceived as quieter and healthier.

• Efficient public transportation active mobility proper vehicle maintenance and effective controls over excessive noise sources are also part of the solution.

In addition it is necessary to move forward with public awareness campaigns. Many sources of noise pollution could be avoided through relatively simple changes in everyday habits: respecting designated hours avoiding unnecessary use of horns keeping vehicles properly maintained and understanding that the volume of a private activity can affect the rest and health of other people #ForABetterWorld.

Bibliography:

• Agencia de Protección Ambiental (APrA) – Government of the City of Buenos Aires. Strategic Noise Map of the Autonomous City of Buenos Aires. Available at: https://buenosaires.gob.ar/gcaba_historico/impacto-acustico/mapa-de-ruido

• Basner, M., Babisch, W., Davis, A., Brink, M., Clark, C., Janssen, S., & Stansfeld, S. (2014). “Auditory and non-auditory effects of noise on health.” The Lancet, 383(9925), 1325–1332.

• Regulatory Decree 740/07. Available at: https://boletinoficial.buenosaires.gob.ar/normativaba/norma/99330

• European Environment Agency (EEA). (2025). Environmental Noise in Europe 2025. Luxembourg: Publications Office of the European Union. Available as: Environmental Noise in Europe 2025.

• Law No. 1,540 on Noise Pollution Control. Available at: https://www.cedom.gob.ar/legislacion/normas/leyes/RepoLeyes/ley1540.html

• Münzel, T., Sørensen, M., Gori, T., Schmidt, F. P., Rao, X., Brook, J., et al. (2021). “Environmental stressors and cardio-metabolic disease: Part II – Mechanistic insights.” European Heart Journal.

• World Health Organization (WHO). (2009). Night Noise Guidelines for Europe. Copenhagen: WHO Regional Office for Europe. Available through the WHO portal.

• World Health Organization (WHO). (2018). Environmental Noise Guidelines for the European Region. Copenhagen: WHO Regional Office for Europe. Available at: WHO – Environmental Noise Guidelines for the European Region.

• World Health Organization (WHO). Noise. Thematic portal on noise pollution and environmental health. Available at: WHO – Noise.