Delhi Govt Said Air Pollution Reduced By 25% But the Data Is More Complicated

The Centre has submitted two different sets of air pollution data to the two houses of parliament.

New Delhi: As winter comes to Delhi, so does the annual smog and concern around it. Just before that season greets us, the Delhi government recently issued full-page advertisements in several leading newspapers, talking about how air pollution in the city had reduced by 25% thanks to the state’s efforts.

A report in Scroll.in, though, has called into question the data that claim was based on – and pointed to a smoggier reality.

The 25% reduction was said to be in PM 2.5 levels – which had gone down from an average of 154 between 2012 and 2014 to an average of 115 between 2016 and 2018. The data was obtained from the Central Pollution Control Board, which functions under the Ministry of Environment, Forests and Climate Change. An analysis of this data, on which the Delhi government claim is based, was published by the Centre for Science and Environment (CSE) on August 30.

CSE said its analysis was based on air pollution data “submitted to Parliament” by the CPCB. It also said that there were gaps in the data – including “major gaps” between 2014 to 2015, Scroll.in reported.

“The data showed that PM 2.5 levels were recorded as 118 in 2016. This came down to 106 in 2017, but rose to 121 in 2018, a 14% increase,” Scroll.in quoted CSE’s analysis as saying. Despite this, the average for 2016-2018 was 25% less than 2012-2014.

Also read: Could Air Pollution Crisis Come Early This Year?

A big reason to question this, according to the Scroll.in report, is that the government has submitted two different sets of air pollution data to the two houses of parliament. In February, health minister Harsh Vardhan told the Rajya Sabha that the annual average for PM 2.5 levels was 135 in 2016, 124 in 2017 and 115 in 2018.

Just a few months later, in July, environment minister Prakash Javadekar had a different story for the Lok Sabha. He said that the annual averages of PM 2.5 levels in Delhi were 118 in 2016, 106 in 2017 and 121 in 2018 – the same numbers as the Delhi government’s.

A few days after that, minister of state for environment Babul Supriyo reverted to Harsh Vardhan’s numbers in the Rajya Sabha. There was a “reduction of 7.3% in PM 2.5 levels in 2018 over 2017 and 14.8% over 2016”, he told the Upper House – percentage changes matching Vardhan’s February data.

A portion of an advertisement on air quality in TOI, on September 12.

In addition to this intra-governmental confusion, the numbers recorded by the Delhi Pollution Control Committee are vastly different to the CPCB’s ones, Scroll.in says. According to the report, “The annual averages calculated by the Delhi Pollution Control Committee that were accessed by Scroll.in state that the average PM 2.5 levels from 2016 to 2018 was 131, which is 15% lower than the annual average of 154 from 2012 to 2014 – not 25%, as the Delhi government has claimed.”

Experts the news portal spoke to said that data gaps made it difficult to conclude that air pollution had, in fact, reduced by 25%. “We could not get daily averages for 2014 when the CPCB had seven stations. We had to rely on the annual reports published by the CPCB for numbers we could not verify,” Hem Dholakia of Council on Energy, Environment and Water told Scroll.in. “Such gaps do not allow us to reach conclusions about whether such policies have worked or not.”

Also read: Gujarat Pilots Emissions Trading Programme to Tackle Air Pollution

Even before Scroll.in‘s report, analysts were wary of the Arvind Kejriwal government’s 25% claim. Jyoti Pande Lavakare, an independent journalist and co-founder of Care for Air, a clean air awareness and advocacy non-profit, wrote in The Wire, “Air pollution experts agree that there is no data available – at least in the public domain – that clearly validates the chief minister’s claims of  a 25% reduction in pollution as measured by concentration of the deadly microparticulate, PM2.5.”

“However, this isn’t to say that Kejriwal is lying to the people – pollution may just have actually reduced slightly. But unless independent data analysts, air pollution scientists and researchers are able to access to the data which Kejriwal is using to make this claim, no one can say whether this is just another piece of fake news in a post-truth world, a manipulation of cherry-picked statistics or this is indeed true,” Lavakare continued.

With Scroll.in‘s report bringing to light the different data sets that exist – and contradict the government’s claim – Lavakare’s fear of “cherry-picked statistics” may, in fact, be true.