By 11pm after an evening of celebrations and fireworks, levels of coarse pollution particles peaked to more than ten times the safe standard for 24 hours in almost all parts of the city. At RK Puram for instance which pretty much represents entire south Delhi, PM 10 levels started rising rapidly from 8 pm to reach 1320 micrograms per cubic metres by 12am and levels of fine, respirable pollution particles that have serious health impacts peaking to 734 micrograms per cubic metres which is about 12 times the national safe standard for 24 hours. While these were the peak levels and they are usually not compared with ambient air standards, experts said the peaks reflect how poor the air really became and the havoc crackers can play.

The situation was no different in other locations like Mandir Marg, Anand Vihar or Civil Lines. At Anand Vihar PM 10 levels had reached a whopping 2,000 micrograms per cubic metre, 20 times the safe standard. Mandir Marg's PM 10 and PM 2.5 parameters were not showing on the Delhi Pollution Control Committee (DPCC) real time air quality website at 12 midnight. Just before they went off, the levels were extremely high with PM 2.5 at more than 600 micrograms per cubic metres. Punjabi Bagh was also at PM 10 of 1012 micrograms per cubic metres and PM 2.5 of 619 micrograms per cubic metres.

Sulphur dioxide (SO2) levels which can trigger health impacts quickly were also very high on Wednesday and Thursday early morning. Depending on the exposure, SO2 inhalation can lead to bronchoconstriction (inflammation, constriction of air ways) and aggravated asthma symptoms. SO2 levels usually never cross the safe standard in Delhi but were more than twice the standard at most locations at around 11 pm—253 micrograms per cubic metres at Anand Vihar and 259 micrograms per cubic metre at Mandir Marg for instance. Sulphur along with various other toxic compounds and heavy metals are used to make crackers.

Noise levels at residential areas were at equally dangerous levels as per CPCB's real time noise monitoring mostly well above the 70 Db (A) which is the safe standard for industrial locations.

Central Pollution Control Board (CPCB's) air quality index (AQI) indicated "very poor" air quality on Mandir Marg, "severe" at Anand Vihar, Punjabi Bagh and RK Puram. System of Air Quality and Weather Forecasting and Research (SAFAR) under ministry of earth sciences forecasts that Thursday air quality will be in "critical" levels. According to their analysis, this year its cooler than last Diwali which was in October leading to the boundary layer or the lowest part of atmosphere coming further down and trapping pollutants very close to the surface.

All pollution monitoring agencies—CPCB, DPCC and SAFAR will release their analysis and average noise and air pollution levels of this Diwali by Thursday evening.