Noise Pollution – Causes, Effects & Remedies – Explained Pointwise

Noise pollution, an often-neglected environmental and public health concern, has gained renewed attention following the recent Patna High Court verdict directing strict regulation of DJs, loudspeakers and pressure horns. The ruling highlights the urgent need to balance social celebrations and individual freedoms with citizens’ right to a peaceful and healthy environment.

What is Noise Pollution?

• Unwanted sounds are classified as noise. When noises are too loud and persist too long, they become noise pollution. Noise pollution is generally defined as regular exposure to elevated sound levels that may lead to adverse effects in humans or other living organisms.
• Decibels (dB) are the units of measure for indicating the intensity or loudness of a sound. It is a unit for expressing the relative intensity of sound on a logarithmic scale. Since it is a logarithmic scale, even small difference in decibel level indicates orders-of-magnitude difference in intensity of sound e.g., a 60-dB, or 6-bel, sound, such as normal speech, is six powers of 10 (i.e., 10⁶, or 1,000,000) times more intense than a barely detectable sound, such as a faint whisper, of 1 dB.

Source: UNEP Frontiers, 2022

• According to the World Health Organization, sound levels less than 70 dB are not damaging to living organisms, regardless of how long or consistent the exposure is. Exposure for more than 8 hours to constant noise beyond 85 dB may be hazardous.

Source: WHO, Vikaspedia

What are the major causes of noise pollution?

1. Transportation: A large number of vehicles on roads, airplanes flying over houses, underground trains etc. produce heavy noise. Rapid growth in two-wheelers, cars, and commercial trucks creates continuous road traffic noise. According to the Frontiers Report, across the European Union, at least 20% of citizens are currently exposed to road traffic noise levels that are considered harmful to health.
2. Industrial Activities: Many industries use big machines like compressors, generators, exhaust fans, grinding mills etc., which produce a large amount of noise. The 114 dB measurement in Moradabad was an average of measurements reported from a factory in an industrial zone.
3. Construction Activities: Construction of roads, metro networks, buildings, and other infrastructure involves heavy machinery and equipment. Rapid urban redevelopment, metro rail construction, and flyover building involving pile drivers, pneumatic drills, heavy earthmovers, and concrete mixers operating in close proximity to residential zones.
4. Social Events: Noise is at its peak in most of the social events like marriage, parties, pub, disco or place of worship etc. People normally flout rules set by the local administration and create nuisance in the area. Extensive use during festivals (like Diwali) and celebrations, generating peak impulsive noise well beyond 120 dB.
5. Poor Urban Planning: Inadequate zoning and the absence of effective buffer zones often result in noise-generating activities being located near residential areas.
6. Diesel Generators (DG Sets): Frequent use of uncanopied or poorly maintained backup power generators in commercial markets, housing societies, and small businesses during power fluctuations. 

Why are the major harmful impacts of noise pollution?

1. Noise-Induced Hearing Loss (NIHL): Prolonged exposure to sound above 85 dB damages the delicate hair cells within the cochlea, which cannot regenerate. Experts believe that regular exposure to over 85 dB for an 8-hour day or longer can cause permanent hearing damage.
2. Sleeping Disorders: Loud noise can hamper sleeping patterns and may lead to irritation and uncomfortable situations. Even when noise does not fully awaken a person, ambient sounds above 40-45 dB fragment REM and deep slow-wave sleep, leading to daytime fatigue, impaired immune function, and mood disorders. 
3. Chronic Health Problems: Noise pollution is a risk factor for the development of cardiovascular and metabolic disorders such as elevated blood pressure, arterial hypertension, coronary heart disease and diabetes. A conservative estimate indicates that long-term exposure to environmental noise contributes to 48,000 new cases of ischemic heart disease and causes 12,000 premature deaths annually in Europe.
4. Productivity Loss: High levels of noise causes extreme discomfort to workers that adversely impacts their mind and reduces their productivity. This in turn enhances cost of production.
5. Ecological & Wildlife Impacts:
   • Traffic and other urban noises disturb and endanger the survival of other species. For instance, acoustic signals are used in a variety of communication contexts by animals like territory defense, warning of danger, locating or attracting a mate, and caring for offspring. However these functions are severely hindered by noise pollution.
   • Many species tend to adapt to the pollution by altering their behaviour e.g., modifying their signals by switching their vocal frequency or altering their vocalization timing. However, these adaptations can have unintended consequences (like altered vocalization patterns may be considered less attractive by potential mating partner, therefore affecting reproductive success). These consequences might eliminate them from their habitats, with possible significant ecological implications.
   • Low-frequency shipping noise and naval sonar disrupt echolocation and long-distance vocalizations in marine mammals (cetaceans), often leading to mass strandings and altered migration routes.

What steps have been taken to tackle noise pollution?

1. Central Pollution Control Board (CPCB): It is mandated to track noise levels, set standards as well as ensure, via the State units, that sources of excessive noise are controlled. The agency has a monitoring system (National Ambient Noise Monitoring Network (NANMN)) where sensors are installed in major cities and few cities have the facility to track noise levels in real time.
2. Noise Pollution (Control and Regulation) Rules, 2000: Enacted under the Environment (Protection) Act, 1986. The rules define ambient noise levels for various areas like residential, industrial or commercial places during the day and night time.
   

   Note: According to the Rule 3(5) of The Noise Pollution (Regulation and Control) Rules, 2000, an area comprising not less than 100 metres around Hospitals, Educational Institutions and Courts may be declared (by the State Government) as silence area/zone. There are restrictions on certain activities in the Silence Zones like blowing of horns, bursting of sound-emitting fire crackers or use of sound-emitting construction equipment during night time among others.

3. Air (Prevention and Control of Pollution) Act, 1981: Noise was explicitly incorporated into the definition of “air pollutant” via a 1987 amendment. 
4. Restriction on Sound Systems: A nationwide ban on loudspeakers and public address systems between 10:00 PM and 6:00 AM (with strictly limited exemptions for designated cultural events).
5. NGT Noise Mapping Mandate: The National Green Tribunal directed CPCB and SPCBs to map acoustic hotspots, mandate sound limiters on sound amplifiers, and equip police departments with calibrated sound level meters.
6. Source Reduction in Machinery: Mandatory acoustic enclosures/canopies for commercial Diesel Generator (DG) sets and industrial machinery. 
7. Green Belts (“Green Mufflers”): Planting multi-tier dense tree buffers (e.g., Neem, Ashoka, Tamarind) along arterial roads, railways, and industrial perimeters, which can attenuate ambient sound by 10-15 dB.

What are the concerns in tackling noise pollution?

1. Narrow meaning of Sound: Policy makers think of sound only in terms of discomfort, such as transport and industrial noise, rather than investigating how to promote sounds that provide comfort. Natural sounds such as flowing water, birdsong, the wind in the trees etc. are soothing sounds that should be promoted.
2. Jurisdictional Fragmentation & Lack of Ownership: Enforcement is split between local police, municipal corporations, transport departments, and State Pollution Control Boards (SPCBs). Police often treat noise as a low-priority public nuisance rather than a serious environmental pollutant.
3. Corruption: Prevalence of corruption is a key reason due to which industries and commercial establishments keep on disrespecting environmental norms. They prefer paying a bribe rather than investing huge amounts of money on sound reduction technologies. 
4. Low Penal Deterrence: Penalties and fines historically remained too low to serve as an effective deterrent, leading to widespread non-compliance until heavier graded fines were pushed by tribunal interventions.
5. Non-Conforming Mixed Land Use: Rapid, haphazard urbanization means small-scale fabrication units, auto repair shops, banquet halls, and commercial markets directly border residential areas, rendering strict zoning enforcement impractical.
6. High Urban Density & Road Congestion: Dense arterial roads run within meters of high-rise residential complexes. High vehicle density, stop-and-go traffic, and bottlenecked intersections amplify ambient engine and tire noise.
7. Cultural Normalization of High-Decibel Events: Loudspeakers, high-output DJ systems, and firecrackers are deeply entwined with religious festivals, weddings, and political rallies. Enforcement during these events often faces public resistance or political sensitivity.
8. Habitual Honking Culture: Honking is treated as an involuntary driving habit rather than an emergency warning signal, aggravated by a lack of lane discipline and widespread illegal aftermarket modifications (pressure horns).

What are the ways to reduce the Noise Pollution?

1. Soundscape Approach: The focus should be on adopting novel approaches towards noise pollution. For instance, the UNEP Frontiers 2022 recommends adopting a soundscape approach. Under this, experts try to look at the issue of urban acoustic environments more holistically, taking a listener-centered perspective. Soundscape planning aims to deliver pleasant acoustic environments that enhance appreciation of places by people.
2. Green Cover: Focus should also be placed on enhancing green cover. Vegetation in urban environments can absorb acoustic energy, diffuse noise and reduce street amplification. Apart from this, they help in amplifying natural sounds by attracting urban wildlife. This includes measures like tree belts and ‘green roofs’.
3. Pathway interventions: Pathway interventions are engineering solutions that obstruct the path of noise from source to receiver by creating a barrier. Both traditional and innovative materials, made from recycled materials such as plastic and car tyres, have proved effective. For instance, Fiberglass from decommissioned wind turbine blades in Denmark have shown a barrier effect reduction of traffic noise levels by 6-7 dB.
4. Expansion of Real-Time Micro-Grids: Expand CPCB’s National Ambient Noise Monitoring Network (NANMN) to tier-2/tier-3 cities and establish micro-monitoring stations at sensitive urban hotspots.
5. Single-Window Nodal Agency: Establish dedicated Environmental Enforcement Cells within municipal bodies to eliminate the jurisdictional vacuum between local police, transport authorities, and SPCBs.
6. Empowering Field Enforcement: Ensure strict implementation of noise standards and impose effective penalties for repeated violations. Equip traffic police and beat constables with calibrated Type-1/Type-2 digital sound level meters and train them to collect legally robust acoustic evidence for swift penalization.

Conclusion: Noise pollution is a major environmental problem and is cited as a crucial factor causing risk to health across all age and social groups. Its magnitude and extent is more visible in urban regions, hence a greater focus should be given to them keeping in mind the SDG 11 that calls for creating sustainable cities and communities.