Context: The city of Moradabad in Uttar Pradesh is the second-most noise polluted city globally, according to a recent report by the United Nations Environment Programme (UNEP).
Key highlights of the report

• The highest noise pollution of 119 dB has been recorded in Dhaka.
• The report identifies 13 noise polluted cities in South Asia.
• Five of these, including Moradabad, are in India, which have recorded alarming levels of noise pollution:  Kolkata (89 db), Asansol (89 db), Jaipur (84 db) & Delhi (83 db).

Nosie 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.

Causes

• Traffic noise: Traffic noise accounts for most polluting noise in cities. For example, a car horn produces 90 dB and a bus produces 100 dB.
• Air traffic noise: A single aircraft produces 130 dB.
• Construction sites: Building and car park construction and road and pavement resurfacing works are very noisy. For example, a pneumatic drill produces 110 dB.
• Catering and night life: Bars, restaurants and terraces that spill outside when the weather is good can produce more than 100 dB.
• Animals: Noise made by animals can go unnoticed, but a howling or barking dog, for example, can produce around 60-80 dB.

Impacts
On Humans

• At certain levels and durations of exposure, it can cause physical damage to the eardrum and result in temporary or permanent hearing loss.
• Excessive noise exposure can raise blood pressure and pulse rates.
• It can cause irritability, anxiety, and mental fatigue, and interfere with sleep, recreation, and personal communication.
• Children living in areas with high levels of noise pollution may suffer from stress and other problems, such as impairments in memory and attention span.

On Animals

• Noise pollution can interfere with an animal’s ability to attract a mate, communicate, navigate, find food, or avoid predators.

Prevention and control of noise pollution

• Road traffic noise can be reduced by better designing and proper maintenance of vehicles.
• Noise abatement measures include creating noise mounds, noise attenuation walls and well-maintained roads and smooth surfacing of roads.
• Retrofitting of locomotives, continuously welded rail track, use of electric locomotives or deployment of quieter rolling stock will reduce noises emanating from trains.
• Air traffic noise can be reduced by appropriate insulation and introduction of noise regulations for take-off and landing of aircrafts at the airport.
• Industrial noises can be reduced by sound proofing equipment like generators and areas producing lot of noise.
• Power tools, very loud music and land movers, public functions using loudspeakers, etc should not be permitted at night.
• Use of fire crackers which are noisy and cause air pollution should be restricted.
• A green belt of trees is an efficient noise absorber.