Civic group writes to HSPCB over gaps in air quality data

A city-based civil society group has written to the chairperson of the Haryana State Pollution Control Board (HSPCB), drawing attention to gaps in official air quality data from Gurugram

A city-based civil society group has written to the chairperson of the Haryana State Pollution Control Board (HSPCB), drawing attention to gaps in official air quality data from Gurugram.

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As per an analysis done by the group — Citizens for Clean Air — 10% to 22% of PM2.5 data each day is either erroneous or compromised. While officials did not comment on the veracity of the analysis, they admitted to persisting issues with collection of air quality data in the city.

“We have observed that when we try to access the online monitoring units... the data reading is unavailable on some days for the stations in Gurugram. This frequent failure of air quality monitoring units is causing great concern. To give an example, the data for Gurugram, at various stations, was missing on January 7, January 12, January 14 and January 15,” states the letter, authored and signed by eight members of the collective.

The issue, members of the group pointed out, is perennial at three of the four monitoring sites in the city, namely at Sector 51, Gwal Pahari and Vikas Sadan.

Kuldeep Singh, the HSPCB’s regional officer for Gurugram, said, “There are no issues with the monitors in themselves. The data is not reflecting on the official websites on some days because it is not being relayed to the central CPCB server, perhaps. I have asked a technical expert to look into the matter.”

A deeper analysis reveals more worrying gaps in the data. Abhishek Shrivastava, an environmental engineer and member of Citizens for Clean Air (CFCA), pointed out that between 10% and 22% of daily readings of finer particulate matter with a diameter less than 2.5 microns (PM2.5), across all four monitors, are either missing or erroneous. This was done by scrutinising about 1,201 data points at each monitoring station, which quantifies the amount of PM2.5 present in the vicinity of the device every 15 minutes. The data was analysed from January 1 to 13.

At Vikas Sadan in Sector 11, for instance, 211 of the 1,153 readings available are marked as “None / Null”.

“This is over 18% of data compromised,” said Shrivastava.

“None/Null” readings have been marked in 178 of 1,153 readings for the TERI Gram monitor, while 76 readings are marked below 10 micrograms per cubic metre (µg/m3). “So, in total, 254 out of 1,153 readings available are erroneous. That is over 22% of data compromised,” said Shrivastava.

“The standard expectation of any continuous monitoring system is that at most, data should be less than 5% erroneous, so that systematic interventions, both on short-term and long-term measures can be taken and impact can be monitored. It is evident that any positive action taken by government unfortunately with a system that does not deliver accurate values cannot be identified or scaled,” states CFCA’s representation to the HSPCB, dated January 15.

Ruchika Sethi, a founding member of CFCA, which claims to have over 200 active members across 67 residents’ welfare associations in Gurugram, said, “Correct and timely information about air quality should be freely available to all taxpayers. Such persistent gaps in the data essentially mean that we are not getting an accurate picture of how bad the air is. Given that there is an inadequate number of monitors to begin with, what data we do get should be trustworthy.”

S Narayanan, member secretary, HSPCB, did not directly comment on the contents of the letter. She said, “We have received the communication and are waiting for comments from the field office. The CAAQMS are all outsourced to expert agencies and if there are some issues in connecting to servers we will take up with them and resolve at the earliest.”