Noise pollution and land pollution

Detail

1. What noise pollution is

• Noise pollution is sound that people find unbearable and uncomfortable. It comes from many sources.
• It became a serious concern only recently. New technology brought machines, motor vehicles and aircraft into daily life.
• How noise is measured:
• The unit is the decibel (dB). This is a log scale, not a straight-line scale. Each rise of 10 dB means the sound is ten times more intense.
• Indian standards use dB(A). This is "A-weighted" sound, adjusted to match how the human ear hears.
• They also use Leq (equivalent continuous sound level), which is the average sound energy over a set period [2].

2. Sources of noise

Source type	Examples	Notes
Industrial	Factories, mines	Noise level depends on the type of industry
Construction	Building machines, demolition machines	Mechanised work makes heavy, irregular noise
Transport	Road vehicles, aircraft, trains	The biggest nuisance
Periodic / social	Sirens, loudspeakers at festivals and community events	Short bursts, but very loud
Sea	Ships loading and unloading	Stays inside harbours

• Why traffic noise varies:
• It depends on the type of aircraft, vehicle or train.
• It depends on the condition of roads. Bad roads mean more braking and rattling.

• It depends on the condition of vehicles. Old engines and poor silencers are louder.

• Industrial noise example: NCERT Fig. 9.2 shows noise being monitored at the Panchpatmali bauxite mine. The mine is in Koraput district, Odisha, on the Eastern Ghats. Blasting, drilling and heavy earth-movers make mines high-noise zones.

3. Spatial pattern: noise is location-specific

• Noise is location-specific. It is loudest near where it starts, and it gets weaker the further you go from the source.
• The main hotspots are industrial areas, transport arteries (highways and railway lines) and airports.
• Noise is a serious hazard in metros. There, traffic, construction and crowds all meet in one place.
• CPCB monitoring: The National Ambient Noise Monitoring Network (NANMN) has 70 stations in 7 metro cities: Bengaluru, Chennai, Delhi, Hyderabad, Kolkata, Lucknow and Mumbai. Each city has 10 stations [4].
• Phase I (2011): 35 stations, 5 in each city [4].
• Phase II (2015): 35 more stations [4].

• The stations are placed in all four zone types: silence, residential, commercial and industrial [4].

• The Central and State Pollution Control Boards also carry out special noise checks during festivals, mainly Deepawali [2].

4. Health effects

• Hearing loss. Too much noise damages the hair cells in the cochlea (the snail-shaped hearing organ in the inner ear) [6].
• Raised heart rate and blood pressure, and stress.
• Long-term exposure to traffic noise is linked to heart disease, stroke and heart failure [6].

• WHO lists more harms: disturbed sleep, poorer work and school performance, and tinnitus (ringing in the ears) [5][6].

• WHO guidance values [6]:

• Less than 30 dB(A) inside bedrooms at night.
• Less than 35 dB(A) in classrooms.
• Less than 40 dB(A) yearly night average outside bedrooms.

5. Legal standards: Noise Pollution (Regulation and Control) Rules, 2000

• What the law is: The Rules were made under the Environment (Protection) Act, 1986 and notified on 14 February 2000 (S.O. 123(E)) [3].
• Their aim: to control the sources of noise and keep ambient (surrounding) noise within the set standards [2].
• Who enforces them: each State or UT must name an "Authority" to keep noise within the limits [2].
• Day is 6 am to 10 pm. Night is 10 pm to 6 am [2].

Zone	Day limit dB(A) Leq	Night limit dB(A) Leq
Industrial	75	70
Commercial	65	55
Residential	55	45
Silence zone (at least 100 m around hospitals, schools and courts)	50	40

• The order from strictest to least strict is: silence zone, then residential, then commercial, then industrial.
• In every zone, the night limit is 5 to 10 dB lower than the day limit.
• Supreme Court, In re Noise Pollution (2005): loudspeakers and public address systems are banned from 10 pm to 6 am. The only exception is a relaxation that the government has formally notified.

6. Land pollution

• Land pollution means that land and soil are contaminated by harmful materials. These pollute the soil, lower its fertility and spread into living things.
• Pollutants listed in NCERT Table 9.1:
• human and animal excreta
• viruses and bacteria
• garbage, and the flies and rats that breed in it (vectors: carriers of disease)
• untreated industrial waste
• pesticide and fertiliser residues
• alkalinity
• fluorides

• radioactive matter

• How the damage happens:

• Waste is dumped on land, or chemicals are sprayed on farms.
• The pollutants build up in the soil and make it less fertile, or even useless.
• Some pollutants seep down (percolate) into groundwater.

• Crops take up others, so the pollutants enter food chains.

• FAO evidence:

• Farm sources of soil pollution include fertilisers, animal manure, pesticides, sewage sludge and irrigation with wastewater [7].
• Heavy metals such as arsenic, cadmium, lead and mercury, and excess nitrogen, cut crop yields. They threaten food security and human health once they enter the food chain [7].

• Pollutants bioaccumulate (build up in body tissues faster than they leave) at each step of the food chain [7].

• World example: about one-fifth of China's farmland is polluted with cadmium, nickel and arsenic. This may cost more than 10 million tonnes of food every year [7].

• Links to other parts of this topic:
• Urban garbage dumped on open land: see urban waste (Section 7).
• Soil contamination, salinity and alkalinity: see land degradation (Section 11).

Prelims Hooks

• The unit of noise is the decibel (dB), and Indian standards use dB(A) Leq. The scale is logarithmic, so +10 dB means ten times the sound intensity.
• Noise Rules 2000 were made under the Environment (Protection) Act, 1986.
• The silence zone limits are 50 dB(A) by day and 40 dB(A) by night. The zone covers 100 m around hospitals, schools and courts.
• The industrial zone has the highest limits: 75 by day and 70 by night. The residential limits are 55 by day and 45 by night.
• Under the Rules, night time is 10 pm to 6 am. The Supreme Court banned loudspeakers in this window (2005).
• NANMN has 70 stations in 7 metros: Phase I in 2011 and Phase II in 2015. Lucknow is included, but Ahmedabad and Pune are not.
• The Panchpatmali bauxite mine is in Odisha (Koraput district). NCERT shows it as an example of monitoring industrial noise.
• NCERT names traffic as the biggest source of noise nuisance. At sea, noise stays inside harbours.
• Fluorides, alkalinity and radioactive matter are listed under land pollution in NCERT Table 9.1, not only under water pollution.

Mains Points

• Urban noise is a planning problem:
• Noise is location-specific. It gathers along highways, near airports and in industrial belts.
• So it can be fixed through land-use zoning, for example buffer zones near airports and silence zones near hospitals and schools.

• Other tools are better roads and vehicles, and enforcement by the authorities each State has to name.

• Noise harms health:

• It causes hearing loss, high blood pressure, heart disease and poor sleep (WHO).

• So it should count as a public health issue, not just a nuisance. This supports adding noise to city clean-air and Smart City plans.

• Land pollution links waste, farming and health:

• Open dumping of urban waste (Swachh Bharat Mission) and too much fertiliser and pesticide reduce soil fertility.

• The pollutants then reach groundwater and food chains through bioaccumulation, which threatens food security.

• Policy responses: scientific landfills, waste segregation, Integrated Pest Management, balanced fertiliser use (Soil Health Card) and treatment of industrial waste before it is discharged.