Delhi Sees Its First ‘Poor’ AQI Day Post-Dussehra

What is a Graded Response Action Plan (GRAP)?

1. GRAP is an emergency framework designed to prevent further deterioration of air quality in the Delhi-NCR region once it reaches a specified pollution threshold.
2. Origin: First notified in January 2017 by the Ministry of Environment, Forest and Climate Change.

Implementation

1. The Commission for Air Quality Management (CAQM) oversees GRAP's execution.
2. Sub-Committee Composition: Includes:
   1. Officials from CAQM
   2. Member secretaries from pollution control boards of Uttar Pradesh, Delhi, Haryana, and Rajasthan
   3. Representatives from the Central Pollution Control Board
   4. Scientists from the Indian Meteorological Department (IMD) and Indian Institute of Tropical Meteorology (IITM)
   5. Health Advisor
3. Function: The sub-committee convenes regularly to issue orders for invoking GRAP as needed. In cases of conflicting orders, CAQM's directives take precedence over those from state governments.

Revised Measures

The GRAP categorizes air quality levels into stages, each prompting specific actions:

1. Stage I – ‘Poor’ Air Quality (AQI 201-300)
   1. Enforce National Green Tribunal (NGT) and Supreme Court orders regarding over-aged diesel and petrol vehicles.
2. Stage II – ‘Very Poor’ Air Quality (AQI 301-400)
   1. Implement rigorous actions targeting identified pollution hotspots in the region.
3. Stage III – ‘Severe’ Air Quality (AQI 401-450)
   1. Impose strict restrictions on:
      • BS III petrol and BS IV diesel four-wheelers in certain areas.
      • Possible suspension of physical classes in schools for children up to Class 5.
4. Stage IV – ‘Severe Plus’ (AQI > 450)
   1. Prohibit entry of four-wheelers registered outside Delhi, except:
      • Electric vehicles
      • CNG vehicles
      • BS-VI diesel vehicles

IMPORTANT FACTS FOR PRELIMS

What is the Air Quality Index (AQI)?

1. The AQI is a tool that simplifies complex air quality data into a single, understandable number and color code to communicate the air quality status to the public.
2. Categories: There are six categories in the AQI:
   1. Good
   2. Satisfactory
   3. Moderately Polluted
   4. Poor
   5. Very Poor
   6. Severe
3. These categories help convey the potential health impacts based on pollution levels.
4. Pollutants: The AQI is calculated based on eight key pollutants: PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb. Each pollutant has specific concentration thresholds that determine its impact.
5. Calculation Process:
   1. The sub-indices for pollutants are calculated using their average concentrations.
   2. To determine the overall AQI, data for at least three pollutants must be available, including either PM2.5 or PM10.
   3. A minimum of 16 hours of data is required for an accurate AQI calculation.

What is the Role of the Central Pollution Control Board (CPCB)?

1. CPCB aims to improve air and water quality and provides technical assistance to the Ministry of Environment and Forests.
2. Establishment: The CPCB was established in September 1974 under the Water (Prevention and Control of Pollution) Act.
3. Standards Development: The CPCB develops standards for air and water quality, sets guidelines for pollution control, and monitors compliance across various industries.