Delhi’s air was toxic for 56% of the days in last 5 years, AQI no reliable measure—CAG report

Report tabled Tuesday points at glaring gaps in pollution monitoring & data collection by agencies, says govt doesn't even record critical pollutants like lead.

Delhi has often been in the news for its air pollution | Suraj Singh Bisht | ThePrint

New Delhi: Delhiites breathed toxic air for 1,195 days out of 2,137 days in the last five years, putting residents at risk of severe health ailments and vulnerabilities, a report by the Comptroller and Auditor General (CAQ) on the city’s pollution has highlighted.

The report, which was tabled Tuesday afternoon before the Delhi Assembly, also pointed at some glaring gaps like no information about vehicles in pollution monitoring and data collection by agencies.

For over 56 percent of days in the last five years, it found, the air quality remained in the ‘poor’ to ‘severe’ category. On the Central Pollution Control Board (CPCB) scale, an AQI of 50 or below is considered ‘good’; ‘satisfactory’ when it is between 51 and 100; ‘moderate’ between 101 and 200; and ‘poor’ when it is between 201 and 300. Anything between 301 and 400 is considered ‘very poor’; while it is marked ‘severe’ when AQI is above 400.

“This report has pointed out various shortcomings in the effort made by the Government in controlling vehicular emission such as lack of information regarding the type and number of vehicles plying on Delhi roads and assessment of their emission load, shortage of public transport buses and public transport for last mile connectivity so as to reduce the use of private vehicles, not implementing of less polluting alternatives,” it read.

Apart from locational disadvantage, which makes Delhi vulnerable to dust and smoke from neighbouring states getting trapped in their airshed, it is also a victim of government apathy. Increased vehicular movement, open fires, and road and construction dust are issues that the government agencies have not been able to manage.

In winter, the capital’s woes only become worse. Its internal sources of pollution are teamed with stubble burning smoke from the neighbouring Punjab and Haryana, cracker smoke from Diwali and bonfires. The cold weather further traps these pollutants closer to the ground, making breathing tough in Delhi.

“While there has been a year-on-year reduction in pollution levels in Delhi over the last few years, this reduction is slow and not enough when the health of residents is at stake. Clearly, the action by agencies is not enough,” Anumita Roychowdhury, executive director of research and advocacy at the Centre for Science and Environment, told ThePrint.

Main findings

The CAG report has pointed at significant data lags in pollution monitoring. The report said that the locations of the Continuous Ambient Air Quality Monitoring Stations (CAAQMS) in Delhi did not fulfil the requirements laid down by the Central Pollution Control Board (CPCB), indicating inaccuracies in data generation.

The report stated that this made the AQI—an air quality index used to prompt government action against rising pollution levels—an unreliable measure.

“Requisite data of concentration of pollutants in the air for a minimum of 16 hours in a day were not available with the DPCC (Delhi Pollution Control Committee) for proper air quality monitoring,” the CAG report read.

Delhi, it said, did not have any real-time information regarding sources of pollutants, blaming the government for not conducting any study in this regard.

The report went on to note that Delhi also did not have any information about the type and number of vehicles plying on the roads. This means that the agencies were not in a position to identify which category of vehicles was emitting the most vehicular fumes.

“GNCTD (Government of National Capital Territory of Delhi) was not in a position to identify emissions from different types of vehicles that are generating significant concentrations of pollutants for framing source-wise strategies,” the report read.

It also said that the government was not even recording critical pollutants like Lead, which have, over the years, gained a significant share in Delhi’s pollution profile.

Sunil Dahiya, founder and lead analyst at the environment think tank Envirocatalyst, said that data collection was the very foundation of any pollution reduction initiative in the region.

“Since CPCB and DPCC have the largest network of air quality monitors in Delhi-NCR, all agencies working in the domain rely on their monitoring for their reports, research and suggestions,” Dahiya told ThePrint.

He said if the data itself is unreliable, then the entire exercise of pollution control will be futile.

(Edited by Tony Rai)