New Delhi: Road dust re-suspension has been identified as a significant-yet-under-addressed contributor to air pollution along an 82.5km stretch in the city, spanning from Mayapuri to Punjabi Bagh via National Highway-44 and NH-9. The findings, recorded in a study conducted by CSIR-NEERI and Central Road Research Institute for Commission for Air Quality Management (CAQM), showed that only 34% of the corridor was in good condition, while 66% fell under moderate to poor categories, leading to increased dust accumulation. Conducted in Feb 2025 but shared recently, the study stated that the overall estimated emissions from vehicle movement for PM10 and PM2.5 were 33.8 and 8.2 tonnes/day, respectively.The stretch covering key corridors from Mayapuri, Punjabi Bagh, Azadpur, Mukarba Chowk, Bawana, Ghevra, Tikri Border, Mundka and Peeragarhi was checked through field surveys, dust sampling and traffic assessments. The study found that dust deposition varied widely across locations, with higher accumulation near road edges and medians, while middle lanes had relatively lower dust levels.“The report formed the basis on which CAQM introduced the standard framework to control dust pollution from the roads and open areas in Delhi-NCR,” a CAQM official said.Among the stretches, Ghevra to Punjabi Bagh West Road (NH-9) showed alarmingly high levels of PM10 and PM2.5 emissions, with values of 1,450.5 and 349.5kg/day/km, respectively, which are significantly high for any city road. Bawana to Ghevra metro (NH-9) also exhibited elevated PM levels, with PM10 at 834.9 and PM2.5 at 202kg/day/km.The daily PM10 and PM2.5 emission loads were highest at Ghevra-Punjabi Bagh, which passes through Peeragarhi. The levels are generally higher during peak hours and lower during night hours, which is directly correlated with the pattern of number of vehicles.Dust particles were also passed through a sieve to assess their sizes and the correlation to re-suspension. The analysis showed that nearly 50% of collected dust samples from five locations consisted of particles smaller than 178 micrometres, making them easily airborne.“The road stretch between Tikri Border and Mundka has a high percentage of dust deposition whose particle diameter is less than or equal to (≤) 176 micrometres on roads, followed by Mukarba Chowk, Mayapuri, Azadpur and Narela. This might be due to a combination of factors, including poor condition of roads, irregular maintenance of roads and insufficient dust management practices,” said the report.It added that the dust volume percentage of dust particles of size ≤76 and ≤10 micrometres was found in the range of 13.6% to 42.7% and 1.2% to 3.7%, respectively. “The dust particles below ≤76 micrometres are considered as silt mass, which is being re-suspended in the ambient due to vehicle movement.” The report recommended reduction of dust re-suspension, including paving of road shoulders, improved road maintenance, mechanical sweeping, use of dust suppressants, and plantation along road edges and medians.
