New Delhi: With air quality deteriorating in Delhi-NCR, authorities on Friday issued an advisory for residents, asking them to limit outdoor activities.


The central pollution watchdog has also asked government and private offices to cut vehicle use by at least 30 per cent as air quality in Delhi-NCR inched towards the emergency level.


According to a sub-committee on Graded Response Action Plan (GRAP), meteorological conditions will be highly unfavourable for dispersion of pollutants till November 18 and agencies concerned must be fully ready to implement measures under 'emergency' category.


ALSO READ | TN Rains 2021: IMD Predicts Moderate Rainfall In Chennai, Suburbs On Saturday


Over 4,000 farm fires, accounting for 35 per cent of Delhi's pollution on Friday, played a major role in pushing the 24-hour average Air Quality Index (AQI) to 471 by 4 pm, the worst this season so far, news agency PTI reported.


The Central Pollution Control Board (CPCB) noted that the 24-hour average concentration of lung-damaging fine particles known as PM2.5 in Delhi-NCR has recently crossed the 300-mark and stood at 381 micrograms per cubic metre at 4 pm on Friday.  


This is over six times the safe limit of 60 micrograms per cubic metre.


The GRAP also pointed out that air quality in NCR is most likely to be in the 'emergency' category if the PM2.5 level continues to be above 300 micrograms per cubic metre for the next two days or more.


Advisory Issued By Sub-Committee On GRAP For Delhi-NCR


i. Government and private offices and other establishments are advised to reduce vehicle usage by at least 30 per cent (by working from home, carpooling, optimising field activities etc). People are advised to limit outdoor activities and minimise their exposure.


ii. Concerned agencies must be in complete readiness for implementation of measures under 'emergency' category as per GRAP (Graded Response Action Plan).


iii. Other measures to be followed in the 'emergency' situation include stopping the entry of trucks in Delhi, ban on construction activities and introducing the odd-even car rationing scheme.


The GRAP is a set of anti-pollution measures followed in Delhi and National Capital Region (NCR) depending upon the severity of pollution comes into force in mid-October when air quality levels start worsening.


AQI In National Capital Region


In terms of AQI, the level in Faridabad was 460, Ghaziabad 486, Greater Noida 478, Gurgaon 448 and Noida 488 - all under 'severe' category of air quality at 4 pm on Friday.


An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 "very poor", and 401 and 500 'severe'.


Smog Lingered Over Delhi-NCR On Friday


A layer of eye-stinging smog lingering over Delhi-NCR worsened on Friday evening, lowering visibility to 200 metres at several places in the region.


Even the visibility levels at the Indira Gandhi International Airport and the Safdarjung Airport dropped to 200-500 metres due to moderate fog. It intensified on Friday due to high humidity.


(With inputs from PTI)