[custom_adv] In Tehran, the noise pollution index is measured by the 43 stations set up in the city, based on a unit known as decibel (dB). If the sound pollution exceeds 70 dB, the situation is said to be critical. [custom_adv] Noise pollution can be any unwanted or offensive sounds that unreasonably intrude people’s daily activities. When a person drives by open windows in a street, the sound is something like 70 decibele. [custom_adv] A whisper is 35 dB and a normal room has a sound intensity of 40 dB. At 45 dB, a person cannot sleep. At 85 dB, the ears are damaged, and at 120 dB, it can be explosive, the Persian-language newspaper ‘Salamat’ reported. [custom_adv] The main reasons for noise pollution are mostly heavy road traffic and transport, construction works and industrial and commercial activities. The most noise pollution comes from cars and motorcycles and construction activity. [custom_adv] Tehran city is the most noise-polluted in Iran. Visitors’ attention is increasingly drawn to the high levels of noise and air pollution. It is worse in the city’s central parts. [custom_adv] The first reason for noise pollution is motor vehicles. More than four million cars ply the city, which contribute more than their fair share to noise/air pollution. Older cars usually produce higher sound pollution. The second reason is the motorcycles, especially those without and/or defective silencers and mufflers. [custom_adv] Nearly 25% of transportation vehicles comprise motorcycles that produce noise of 83 dB from a distance of 10 meters; 60% is attributed to cars, of which 47.8% give out noise above 81 dB. The standard average for sound pollution by cars is 74 decibels. [custom_adv] The most noise nuisance is on the highways. Tehran, home to more than 12 million people, has 40 freeways where noise nuisance reaches 75-85 dB. Hence, many residential areas in the vicinity are in critical state.
