WHO guidelines serve as guidance, AQI standards based on national situation: Govt

The environment ministry said it has notified the National Ambient Air Quality Standards for 12 air pollutants to safeguard public health, environment quality.

The World Health Organisation’s (WHO) air quality guidelines serve only as a guidance document and they are recommended values for air pollutants to help countries achieve air quality, the Union environment ministry has informed Rajya Sabha in the ongoing winter session of the Parliament.

A thick layer of smog engulfs the skyline in Delhi NCR as the AQI slips to the ‘very poor’ category.(Sunil Ghosh/ HT Photo)

“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 (MoS) for environment said.

He was responding to questions by Communist Party of India (Marxist) (CPI-M) MP, V Sivadasan.

Sivadasan asked three questions to the ministry. His first question was 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-wise. Second was on the key parameters used by these indices for assessing pollution levels and third, whether the ministry has undertaken any review of the country’s performance in these international indices among others.

“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 (7th September),” the ministry replied.

HT reported on September 23, 2021 that harm from air pollution begins at much lower levels than previously thought, the WHO said as it 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 15µg/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 much 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).

“Focussed policy interventions”

Further, in response to a question on Delhi’s air quality in Rajya Sabha, Union environment minister, Bhupender Yadav said with focussed 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 air quality days (AQI<200) have increased to 200 days in 2025 from 110 days in 2016. The average AQI of Delhi for the period January – November during the current year has been recorded as 187 as against 213 in 2018.

In 2025 so far, 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 the year 2025 in comparison to the same period in the year 2022,” he added.