: The Delhi government doesn’t plan on studying the ultrafine and ultra dangerous PM1 particles as part of its air quality monitoring programme for round two of odd-even.
The government had announced that it would be collecting samples of particulate matter that are below 1 microns in diameter during the first vehicle-rationing experiment in January.
This would have been the first such study on a large-scale in Delhi.
However, sources in the Environment Department and the Delhi Pollution Control Committee, which monitors air quality, said PM1 was not studied last time, and is not on the cards this time either.
That is because PM1 is a fairly recent discovery and there are no standards set for it. So, even if the amount of PM1 in the air is known it can’t be compared to anything as no yardstick or safe limit has been set.
A report on the “lessons learnt from odd-even” does not have a mention of PM1, and the DPCC’s plan for monitoring in round two of odd-even only refers to PM2.5 and PM10. The Hindu has a copy of both documents.
That being said, PM1 is covered under PM2.5, which are particulate matter 2.5 microns or less in diameter. But, there is no separation of the data. Also, the hand-held devices used during odd-even have the capability to detect PM1, but officials said it would be a futile exercise as they would have nothing to compare it to.
The media advisor to Chief Minister Arvind Kejriwal, Nagendar Sharma, who had announced at a press conference on January 4 that PM1 would be studied, on Wednesday declined to comment on whether that was carried out last time and if it would be done this time.
Experts say that the smaller the particle, the more harmful it is. PM1 is so small that it can enter the blood stream and cause serious problems.
Anumita Roychowdhury, who heads the Centre for Science and Environment’s clean air campaign, said that data of PM1 could be used for research purpose as it is not regulated yet.
“It would be good to know. We need to come up with a framework on how to monitor and mitigate PM1. It is not monitored regularly anywhere in the world, but it is important from the perspective of setting emission norms,” said Ms. Roychowdhury.
Meanwhile, preparations for the second phase of odd-even, which will be held from April 15 to 30, began on Wednesday. The DPCC, which will be covering 119 locations in Delhi during the scheme, started by collecting PM2.5 and PM10 samples from 42 locations, and NO2 samples from 10, said a senior scientist.
All the 119 locations will be covered twice – at the same time of the day – before odd-even begins. This will allow a comparison of data from before and during odd-even. Last time, the DPCC had covered 246 locations, but had only one set of data for each site so comparisons were not possible.
“There will be a qualitative difference this time as the same place will be covered at the same time on consecutive days,” said Kulanand Joshi, the Special Secretary of the Environment and Forest Department.
