E-Paper
India’s air quality standards based on localised factors, says Union ministry
According to the 2009 National Ambient Air Quality Standards still in force, the acceptable PM2.5 exposure limit over 24 hours is 60µg/m³
New Delhi
The World Health Organization’s (WHO’s) air quality guidelines are globally recommended standards to help countries achieve air quality and serve only as a guide document, but countries determine their standards based on a variety of localised factors, the Union environment ministry informed the Rajya Sabha.
“However, countries prepare their air quality standards based on geography, environmental factors, background levels, socio-economic status and national circumstances,” Kirti Vardhan Singh, minister of state for environment, said.
He was responding to a three-part question raised by CPI(M) MP V Sivadasan. The first part sought information on the country’s global rankings in the IQAir World Air Quality Ranking, the WHO Global Air Quality Database, the Environmental Performance Index (EPI), and the Global Burden of Disease (GBD) air-pollution metrics since 2020, year by year. In the second part, the MP sought to understand the key parameters used by these indices for assessing pollution levels, and in the third part, sought to know whether the ministry has undertaken a review of the country’s performance in these international indices.
“The ministry of environment, forest and climate change (MoEFCC) has notified the National Ambient Air Quality Standards (NAAQS) for 12 air pollutants to safeguard public health and environment quality. However, MoEFCC conducts Swachh Vayu Survekshan annually to rank 130 cities which are covered under NCAP based on implementation of various air quality improvement measures. Better performing cities are felicitated annually on National Swachh Vayu Diwas (September 7),” the ministry said.
Kirti Vardhan Singh also said in the same response: “Worldwide ranking of cities for pollution levels is not being conducted by official authority.”
HT reported on September 23, 2021, that the adverse effects of air pollution begin at much lower levels than previously thought, as the WHO lowered acceptable thresholds for several pollutants, including ultrafine PM2.5 particles that India has typically struggled to contain. According to the new thresholds, the average 24-hour exposure to PM2.5 must remain below 15 micrograms per cubic metre (µg/m³), down from 25µg/m³. In case of PM10 particles—typical dust particles—the safe threshold has been lowered from 50 to 45µg/m³. In terms of exposure over a year-long period, the threshold for PM2.5 has been brought down from 10 to 5µg/m³ and for PM10, from 20 to 15µg/m³.
In comparison, India’s thresholds are manyfold higher.
According to the 2009 National Ambient Air Quality Standards still in force, the acceptable PM2.5 exposure limit over 24 hours is 60µg/m³ (four times the new WHO limit) and for exposure over a year-long period, 40µg/m³ (eight times the revised WHO threshold).
In response to a question on Delhi’s air quality in Rajya Sabha on Thursday, Union environment minister Bhupender Yadav said that with focused policy interventions and continued strengthening of field-level implementation, the air quality in Delhi-NCR has improved progressively in the last few years. The number of good days (when the air quality index is below 200) has increased to 200 days in 2025 from 110 days in 2016. The average AQI of Delhi for the January–November period in the current year has been recorded as 187, against 213 in 2018.
In 2025, AQI levels have not reached “severe plus” (AQI>450) level for a single day in Delhi. “With the coordinated efforts, the states of Punjab and Haryana have collectively recorded about 90% reduction in fire incidences during paddy harvesting season in 2025 in comparison to the same period in 2022,” he said.
