A bench headed by the National Green Tribunal chairperson, Justice Swatanter Kumar, directed environment and forest department secretary, health secretary, Delhi Pollution Control Committee chairman and member secretary to hold a meeting on the worsening pollution in the city on Wednesday itself, at 4 pm.

The NGT intervention came as the city has been experiencing sharp deterioration in air quality. City residents now are on the verge of facing serious health risks as the most prominent pollutant across monitoring stations in Delhi has been identified as PM (particulate matter) 2.5, having the size equal to or less than 2.5 micron, the tiniest and deadliest.

Unlike other countries, there’s no protocol in Delhi for warning residents when pollution levels spike and with onset of winter, the city experiences deadly smog daily — mostly attributed to burning of crop residue, leaves, rubber and garbage.

Permissible levels of particulate matter 2.5 and 10 are 60 and 100 micrograms per cubic metre respectively and consistent exposure to anything beyond that can harm the respiratory system as the particles embed themselves deep inside the lungs. These respirable particulate matters, a product of vehicle emissions, burning of waste, industrial fumes, and especially PM 2.5, are considered by the World Health Organisation as the best indicator of the level of health risks from air pollution. The green panel on Wednesday directed the Delhi government to issue a notification within a week with regard to areas in the capital which are most polluted and enumerate steps needed to check air pollution in the city.

“What is the status of air pollution? All you can say is that there is no pollution... All stakeholders who are dealing with air pollution indicate that Delhi is highly polluting. The level of PM 2.5 and PM 10, both are more than prescribed limits. We cannot permit such state of affairs causing serious environmental pollution to prevail,” the bench said.

The worsening state of the air pollution in the city was highlighted by the fact that in seven out of 10 monitoring stations of the Central Pollution Control Board, PM 2.5 was identified as the major pollutant.

However, in Anand Vihar, the most polluted spot in the city, PM 10 had more presence. PM 10 is the particular matter having the size equal to or less than 10 micron. The Delhi Pollution Control Committee’s real-time monitoring showed PM 2.5 and PM 10 at 191 and 611 respectively and R.K. Puram had the corresponding figures at 220 and 458 at around 12.30 pm. Air Quality Index of System of Air Quality and Weather Forecasting and Research (SAFAR) stations, located across the city, also hovered between very poor and poor.

Dhirpur station’s PM 2.5 and PM 10 levels were 392 and 369 at 12.55 pm. “Very poor” signifies PM 10 and PM 2.5 levels between 351 and 420 and 211 to 252 micro gram per cubic metre. “Severe” is declared when PM 2.5 and PM 10 cross 253 and 421 micro grams per cubic metres respectively. The NGT also directed the Central Pollution Control Board to seek information from various states and Union Territories on ambient air quality in their area and submit a report to the bench.

The tribunal also asked the state governments suggest ways to combat air pollution in their respective states. The panel also sought a report from the National Highways Authority of India and the Haryana government on the status of Eastern and Western Peripheral Expressways. On the issue of alternative routes used by commercial vehicles, the Haryana government told the tribunal that nearly 6,000 to 7,000 vehicles were being diverted at Panipat through alternative route via NH-71A and NH-71.

Dismayed at increasing air pollution in the national capital, the tribunal had earlier banned all vehicles more than 15 years old from plying on the city roads. On April 7, the green panel held that all diesel vehicles over 10 years would not be permitted to ply in Delhi-NCR.

In a recent recommendation report to the Delhi government, an IIT Kanpur team suggested a switch to Euro VI norms among other measures to combat the pollution menace.