LUCKNOW: Indiranagar is the most polluted residential colony in the state capital as far as air and noise pollution are concerned. According to the environmental status report of Industrial Toxicology Research Centre (ITRC), the level of suspended particulate matter (SPM) causing respiratory ailments and heart diseases stands at 442.8 micrograms per metre cube which is even higher than the SPM levels found in commercial areas of Hussainganj (432.2), Charbagh (414.5), Alambagh (389.4), Aminabad (400.7) and Chowk (361.0). Similarly, the level of respiratory suspended particulate matter (RSPM) in this residential colony stands at 199.9 micrograms per metre cube, surpassing that of commercial area of Hussainganj which stands at 180.3 micrograms per metre cube. Not only this, the level of lead in the air in Indiranagar area is at 0.181 microgram per metre cube which is almost the double the Charbagh's 0.091 microgram per meter cube. Spurt in construction activities, decline in the number of trees and increased vehicular traffic density are the main reasons for the increase in air pollution, say the ITRC experts. "Polluted air has adverse effect on people, specially infants, children, elderly people and people with asthma, bronchitis etc. Exposure to such air results in an increase in bronchitis, respiratory ailments, oedema of lungs, cardiovascular diseases and dust allergies," said a scientist at the Indian Toxicology Research centre (ITRC), JS Gaur. Elaborating on SPM and RSPM, Gaur said that air contains gases and dust particles. Bigger particles are filtered by the nasal hair but the smaller ones are inhaled, which are termed as (RSPM). They get lodged deep down the lower respiratory tracts causing several diseases. Polluted air contains traces of heavy metals like copper, nickel, lead, iron, chromium, cadmium, anthrecene, pyrene and chryseen. Indiranagar has topped the chart in noise pollution too, leaving behind even the commercial areas of Hussainganj, Charbagh, Alambagh and Aminabad. Not only this, the colony recorded the highest noise level both during the day as well as night. The figures stood at 77.9 decibel (dB (A)) during the day exceeding the prescribed limit of 55 dB (A) during the day and 73.2 dB (A) at night again exceeding the prescribed limit of 45 dB (A). While at commercial areas of Hussainganj, Charbagh, Alambagh and Aminabad the noise level stood at 74.9 dB(A), 76.6 dB(A), 77.1 dB(A) and 75.1 dB(A) during the day time. During night also it left behind areas like Hazratganj, Hussainganj, Charbagh, Aminabad and Chowk. Elevated noise levels have been associated with adverse impact on human health ranging from minor annoyance to physiological damage, say scientists.