Odd even II: Air quality will be checked at 7 entries to Delhi

The Delhi government will from Wednesday monitor air quality at the city’s seven main entry points, allowing it to measure the difference in pollution levels when the road-rationing plan returns on April 15.

These entry points see heavy traffic, especially diesel-guzzling trucks. The Supreme Court has banned heavy vehicles from passing through the city and the trucks that get to enter have to pay a pollution surcharge.

Hand-held devices would also be used at 55 locations in the city to measure air quality, sources said. Delhi, which according to the WHO has the dirtiest air in the world, has six pollution monitoring centres.

At the entry points, readings will be taken at the border, one kilometre inside Delhi and at a similar distance in the neighbouring state.

“These are heavily polluted corners of the Capital because of the massive vehicular traffic,” an official said. Noida, Ghazipur, Tikri, Shahdara and Anand Vihar on Uttar Pradesh side and Badarpur border and Gurgaon in Haryana are the places picked for monitoring.

When Delhi restricted the use of private cars in January, experts said for the city’s air to be clean, the entire National Capital Region would have to chip in.

“By taking samples from Delhi -- where odd-even scheme will be in force -- and from across the border where the number of cars is going to be unchanged, the Delhi Pollution Control Committee will be able to see the difference between pollution levels and measure the impact,” the official told HT.

During the first phase of the odd-even scheme when only odd-numbered private cars were allowed on odd days and even on even days, data was collected from 246 locations but only for a day per spot. It made any comparison difficult.

The second phase will not face such a problem. Data will be available for normal traffic days as well as during the 15-day road-rationing period. Same locations will be monitored multiple times.

Hand-held devices, monitoring stations and mobile stations will all keep a watch on air quality.

The national green tribunal, too, on Tuesday asked for data for seven days and also set up a committee to collect air samples from different locations before April 15.

Pollution levels were high on Tuesday. The concentration of PM 2.5, particulate matter with a diameter of 2.5 microns that can penetrate deep into the lungs, was 145 micrograms per cubic metre, data from the government’s System of Air Pollution Monitoring and Forecasting (Safar) showed. India’s permissible level is 60 µg/m3 against the WHO’s 25 µg/m3 safe limit. Wednesday could be worse with PM 2.5 levels expected to rise to 159µg/m3. The air quality was “moderate”.

.