Knowledge Nugget: How is GRAP, Delhi-NCR’s action plan to combat rising air pollution relevant for UPSC Exam?

The dip in AQI had prompted the Commission for Air Quality Management (CAQM) in the National Capital Region and Adjoining Areas to activate Stage 1 of the Graded Response Action Plan (GRAP) to tackle pollution. In this context, let’s know about the ground-level ozone and GRAP in detail. 

Key Takeaways :

1. There are two types of ozone – one in the upper atmosphere, which creates a shield against harmful ultraviolet rays and ground-level ozone, exposure to which may increase frequency of asthma attacks, can aggravate lung diseases such as emphysema, and chronic bronchitis, and inflame airways.

2. Ground-level ozone is not emitted directly but is formed on warm and sunny days when oxides of nitrogen (NOx) and volatile organic compounds (VOC) react with each other. Both are emitted because of vehicular pollution by cars, power plants and industries. Ground-level ozone pollution is primarily an urban affair.

Graded Response Action Plan (GRAP)

1. Graded Response Action Plan (GRAP) is a set of emergency measures that kick in to prevent further deterioration of air quality once it reaches a certain threshold.

2. Stage 1 of GRAP is activated when the AQI is in the ‘poor’ category (201 to 300). The second, third and fourth stages are activated three days ahead of the AQI reaching the ‘very poor’ category (301 to 400), ‘severe’ category (401 to 450) and ‘severe +’ category (above 450) respectively.

3. Measures being imposed under the previous categories continues even when the subsequent category is activated, that is, if measures under Stage-2 are activated, measures under Stage-1 will continue to remain in place.

4. Notably, the GRAP was first notified in January 2017 by the Ministry of Environment, Forest and Climate Change. This was based on a plan that was submitted by the CPCB in November 2016.

5. According to the notification, the task of implementing the GRAP fell on the now-dissolved Environment Pollution (Prevention and Control) Authority for the NCR. From 2021 onwards, the GRAP is being implemented by the CAQM.

Air Quality Index (AQI)

1. AQI was launched by the central government in 2014 as part of the Swachh Bharat campaign to help simplify the common understanding of pollution. An expert group comprising medical professionals, air quality experts, academia, advocacy groups, and others was constituted and a technical study was awarded to IIT Kanpur. IIT Kanpur and the Expert Group recommended an AQI scheme.

2. According to the CPCB, the AQI transforms complex air quality data of various pollutants into a single number (index value), nomenclature, and colour. The pollutants measured include PM 10, PM 2.5, Nitrogen Dioxide, Ozone, Carbon, etc.

3. There are six categories of AQI, namely ‘Good’ (0-50), ‘Satisfactory’ (51-100), ‘Moderately polluted’ (101-200), ‘Poor’ (201-300), ‘Very Poor’ (301-400), and ‘Severe’ (401-500).

4. PM 10 and PM 2.5 pollutants are extremely fine particulate matter (PM) particles, with the digits accompanying them referring to their diameter. So, PM 10 and PM 2.5 are smaller than 10 and 2.5 microns in their diameter, respectively. The finer the particles are, the more difficult it gets to protect oneself from them.

5. Due to their size, the PM 2.5 particles can easily bypass the nose and throat and can enter the circulatory system. The particles can also lead to chronic diseases such as asthma, heart attack, bronchitis, and other respiratory problems.

BEYOND THE NUGGET: Commission for Air Quality Management in NCR and Adjoining Areas (CAQM)

1. The CAQM was constituted through the CAQM Act, 2021, which came into force in the same year on April 13. The air quality monitoring body is tasked with better coordination, research, identification, and resolution of problems surrounding the air quality index and related matters in NCR and adjoining areas.

2. CAQM has the power to take measures, issue directions and entertain complaints to protect and improve the air quality in the region.

3. The Commission is required to have a full-time chairperson with experience of not less than 15 years in the field of environmental protection and pollution control, or administrative experience of not less than 25 years.

Post Read Question

Consider the following statements:

1. Ground-level ozone pollution is primarily an urban affair.

2. Ground-level ozone is formed on warm and sunny days when oxides of nitrogen (NOx) and volatile organic compounds (VOC) react with each other.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

(Sources: Air in Delhi turns ‘poor’ after four months, high ozone levels recorded; GRAP Stage 1 activated ,What is GRAP?, What is AQI — and how is it measured? )

Subscribe to our UPSC newsletter. Stay updated with the latest UPSC articles by joining our Telegram channel – Indian Express UPSC Hub, and follow us on Instagram and X.

🚨 Anniversary Special: Read the UPSC Essentials September 2025 special edition, celebrating two years of the magazine! Share your views and suggestions at manas.srivastava@indianexpress.com 🚨