Not even silence zones spared as traffic gives Delhi an earful

NEW DELHI: A dynamic mapping of noise pollution at 10 locations by Delhi Technological University (DTU) has revealed that traffic noise levels were much higher than the standards set by Central Pollution Control Board (CPCB) during evenings compared with morning hours.

The selected locations consisted of different land-use patterns, including industrial, commercial, residential and silence zones. Not only residential and commercial zones, but even silence zones also violated the permissible limits.

The study, published in Arabian Journal of Geosciences, made an attempt to analyse the spatial distribution of traffic noise levels in the city by creating noise maps with the help of Geographic Information System (GIS).

During the morning peak hours (8am to 10am), the traffic noise level was maximum at Badli crossing (78.8 dBA), whereas the minimum was observed at Patel Nagar Chowk (71.4 dBA). During the evening peak hours (5pm to 7pm), the traffic noise level was minimum (74.1 dBA) at Shastri Park, KG Marg and Tolstoy Marg, while the maximum (81.1 dBA) was seen at Peeragarhi Chowk and Badli crossing.

In the case of off-peak hours (from 12pm to 2pm), Paharganj Chowk showed the highest traffic noise level at 73.3 dBA, while the lowest (64.3 dBA) was found at Shastri Park, KG Marg and Tolstoy Marg.

The traffic noise level was observed at a distance of 1m from the edge of the road, while the height of the sound-level meter was 1.5m as it is considered the average height for the human ear. The researchers then used GIS software to map noise at the 10 locations.

The study mentioned that the noise level was directly proportional to the volume of traffic. “The average road traffic noise level in the morning peak hours varied from 68.5 to 80.4 dBA. In the evening, it was between 71.9 and 83.7 dBA. During off-peak hours, it varied between 64.2 and 73.3 dBA. When traffic increased during off-peak hours, the average noise level also rose,” it added.

Rajeev Kumar Mishra, assistant professor in department of environmental engineering at DTU, said that Delhi was one of the worst-affected cities. “The noise levels are very high compared with CPCB’s limits. The vehicular population in Delhi jumped by 135.6% from 1999–2000 to 2015–2016. There were 10.6 million vehicles in May 2017. Prolonged exposure to noise can cause hearing loss. This induced hearing impairment occurs at a frequency range of 3,000–6,000 Hz,” he added.

Mishra said other issues included psychological effects, such as fatigue, lack of concentration, sleeping disorders, etc. He added that there was an urgent need for mitigating measures, like noise barriers to curb such pollution and its associated adverse health impacts. “People don’t realise the impact it can have on them,” said the assistant professor.