If you were anywhere between Victoria Memorial and Esplanade on Wednesday evening, we hope you held your breath. For, the air around the Maidan during and after the CPM-backed rally was pure poison.
The fact that your lungs were under severe threat is borne out by figures. The 24-hour automatic air quality system set up by the pollution control board on the Victoria Memorial premises pegs the respirable particulate matter (RPM) average count for December 27 and 28 at 380 micrograms per cubic metre of air.
The permissible RPM count ' concentration of dust particles small enough to reach the deep crevices of lungs and trigger lung-related diseases ' is 100.
Anything above the 100 RPM mark is a threat to our lungs; RPM 380 micrograms is a killer count.
So much for the claims of the authorities ' defence minister and chief minister included ' that all they needed to do to clear the air about the assault on the Brigade Parade Grounds was mop up the paper and the plastic.
That the Maidan area was far more polluted in the 48 hours of the run-up and the rally, is clear from the count on the Memorial monitor for Monday, December 26 ' RPM 241 micrograms, a sharp drop of around 40 per cent.
And that the mayhem on the Maidan was to blame is evident from the city pollution average measured by pollution control board monitors on December 27 and 28 ' RPM around 230 micrograms.
'From the data it is quite clear that the particulate level for those two days reached hazardous levels in and around the Maidan,' said an environment department official.
'We must also take into account the fact that the air monitoring system in Victoria Memorial is surrounded by greenery and so the actual RPM level in the area must have been significantly higher. Moreover, the particulate level was definitely much more than RPM 380 micrograms during the rally and till at least five hours after that (2 pm to 10 pm) on Wednesday,' he added.
A study carried out by the pollution control board a few years ago at public places like the Book Fair and zoo had showed how dust particles in winter disperse slowly and tend to settle down only after four to six hours.
The particulate level at these places was found to be two to three times the average normal winter value for the city.
And the dust storm raised by the rallyists on Wednesday would have taken several hours to settle, pushing the pollution peril to alarming levels.
'The finding is scary not just for the health of the people exposed but also in context of saving Victoria Memorial,' said environment activist Subhas Dutta.
'I will definitely raise the matter in court,' added Dutta, who has been carrying on a crusade to preserve the Maidan and also the Memorial.
World Bank studies have earlier proven how 'a few thousand' die every year in Calcutta, and many more suffer, from diseases caused by air pollution.
How many lungs did the Wednesday rally claim'