Rail traffic noise in slums far over WHO norms, reveals study

Residents of slum clusters along Delhi’s railway tracks are living amid dangerously high noise levels that surpass global safety limits, a new scientific study has revealed.

The research, jointly conducted by the Delhi Technological University (DTU) and the CSIR–Central Road Research Institute (CRRI), monitored more than 1,000 train pass bys across 14 locations in the National Capital Territory. The findings, published in the journal Environmental Monitoring and Assessment, point to a public health emergency unfolding in some of the city’s most vulnerable communities.

Levels far above limits

According to the study, average sound levels in these settlements routinely exceeded the Central Pollution Control Board (CPCB)’s permissible limit of 55 decibels for residential areas. At Patel Nagar, one of the noisiest locations surveyed, levels touched 120 decibels — equivalent to standing next to a chainsaw. Even the “quietest” site, Shahdara, recorded 69 decibels, still 26 per cent above the safety threshold.

The World Health Organisation (WHO) recommends community noise levels remain below 55 decibels during the day and 40 decibels at night to prevent health risks such as sleep disruption, anxiety, cardiovascular disease and impaired cognitive functioning. In Delhi’s rail-side slums, however, noise was consistently two to three times higher than those standards.

Environmental justice

The study highlights that Delhi has 775 slum clusters, of which nearly 10% are located on or adjacent to the Railways’ land. This translates to more than three lakh households exposed daily to hazardous noise without effective protection.

Lead researcher Mishra, along with co-author Ravi Pratap Singh Jadon, under the leadership of Geeta Singh from the DTU and in collaboration with Nasim Akhtar, Chief Scientist at CRRI, emphasised that absence of sound barriers made these communities vulnerable.

Solutions, recommendations

The study strongly recommends urgent policy interventions to protect residents from escalating noise exposure.

Researchers suggest accelerating the shift from diesel to electric locomotives, as electric trains consistently emit lower sound levels across categories. They also call for the construction of sound barriers along rail-side settlements, rerouting of freight traffic away from densely populated areas, and restricting diesel train operations in residential zones.

Besides, regular noise audits and targeted monitoring of identified hotspots are advised to ensure accountability and long-term reduction of noise pollution. If implemented effectively, these could significantly improve the living conditions of thousand.

Now, global cities such as London and New York have successfully reduced community noise through strict scheduling and installation of acoustic barriers.