The health emergency in Delhi shows not signs of letting up. The intense and dangerous smog that descended on the city the day after Diwali has only been thickening with sensors measuring air quality registering an ominous rise in levels of pollutants over the past week.

The Air Quality Index maintained by the Indian Institute of Tropical Meteorology shows that on Sunday levels of particulate matter below 10 microns or PM10 are at an astounding level of 825 micrograms per cubic metre and that of the even more dangerous PM2.5 is at 550 micrograms per cubic metre. The acceptable standard according to Indian regulations are 60 micrograms per cubic metre for PM10 and 40 micrograms per cubic metre for PM2.5. Even these levels are much higher than the norm prescribed by the World Health Organisation – not more than 10 micrograms per cubic metre.

The forecast for the next couple of days suggests air quality might improve but only from being "severe" to "very poor".

But even as air quality numbers rise and fall, Delhi residents have been looking with trepidation out of their windows every day at the very visible worsening of the air around them. Some citizens have documented the change in "before and after pictures" that are worth thousands of words.

Delhi's air is the best instagram filter. #Delhipollution #concentrationcamp

A photo posted by Aradhya Agnihotri (@aradhya.agno3) on

HAPPY DIWALI ? 😐 #DelhiPollution #Smog

A photo posted by Meghana Trivedi (@idkitsurgent) on