If you could see past your past nose today, you might have noticed the haze is especially thick, like soup left out since before diwali.

The quality of the air in Delhi has always been dire, but this yes, the city has managed to outdo itself. Here is the comparative data for the last four Diwalis by the System of Air Quality and Weather Forecasting and Research (SAFAR), a Ministry of Earth Sciences initiative to provide location specific information on air quality in Delhi, Mumbai and Pune.

D: Diwali
NAAQS: National Ambient Air Quality Standard
And it’s not going to improve soon.

However it’s not fair to lay this all on Diwali’s door, apart from the pollution from bursting crackers, other environmental factors have contributed to the deteriorating Air Quality Index (AQI).

The “wind speed of 6km/hr on 28th October has continuously fallen and became less than 1km/hr on 30th Oct night till 31st Oct morning. Temperature remain low (15˚C) during Diwali night. This scenario has contributed to significant increase in AQI,” the SAFAR report says.

Wind speeds greatly impact the aount of time that Particulate Matter (PM) stay in the atmosphere. “Under normal metrological conditions, the PM can disperse within a day or two,” Dr MP George of Delhi Pollution Control Committee told Newslaundry today.

“A day or two” is an awfuly long time when the AQI is at its most dangerous of level — Severe.

Yet, there is a catch when it comes to Diwali. When a cracker is burst, apart from all the pollutants that go out, there are also —heavy metals and their often toxic compounds.

“Crackers, depending on their make, can release heavy metals like lead, zinc, cadmium, copper, manganese, sodium, magnesium and potassium,” said Ravi Agarwal of Toxics Link, an NGO working to bring information on toxic materials into the public eye. Agarwal also added that upon combustion, oxides of these metals in the form of sulphates and phosphates are also formed. “These compounds sit on top of the particulate matter in the atmosphere and have very harmful health impacts,” he said.   

Although it is true that the base pollution levels are high throughout the year in Delhi, Diwali, undoubtedly adds its own significant charm.

“If you burn anything it will harm the environment,” Dr George said.