Delhi Air Pollution: Delhi-NCR Breathes Easier as GRAP Stage-III Withdrawn Amidst Improving Air Quality

The residents of Delhi-NCR can finally breathe a sigh of relief as the Commission for Air Quality Management (CAQM) announced the immediate withdrawal of restrictions under the Graded Response Action Plan (GRAP) Stage-III, also known as the 'Severe Category'. This significant decision comes after a noticeable improvement in the region's air quality over the past few days, offering a much-needed respite from the choking pollution that has plagued the capital. The move reflects a positive shift in the environmental conditions, signaling a temporary victory in the ongoing battle against air pollution.

Decision Based on Comprehensive Review

The crucial decision to roll back GRAP Stage-III was made following a thorough review by the Sub-Committee of the CAQM. This committee convened on Wednesday to meticulously assess the prevailing air quality parameters across Delhi-NCR, while their deliberations were further informed by detailed forecasts provided by the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM). These expert projections played a vital role in determining the current and anticipated air quality trends, providing the scientific basis for the CAQM's action, while the collaborative assessment ensured that the decision was well-founded and responsive to the actual environmental situation.

Consistent Improvement in Air Quality

A primary factor driving the withdrawal of GRAP Stage-III has been the sustained improvement in Delhi's Air Quality Index (AQI) over the last four consecutive days. This consistent positive trend indicated a significant departure from the 'Severe' category that had necessitated the stringent measures. On the day of the announcement, Delhi's AQI was recorded at 327, which, while still in the 'Very Poor' category, represents a substantial improvement from the 'Severe' levels observed previously. This downward trajectory in pollution levels provided the necessary confidence for the authorities to ease some of the stricter restrictions.

Continued Vigilance with Stage-I and Stage-II

Despite the withdrawal of GRAP Stage-III, the CAQM has emphasized that the measures under Stage-I and Stage-II will remain actively enforced across the Delhi-NCR region. This cautious approach underscores the ongoing commitment to maintaining and further improving air quality. All concerned agencies have been explicitly instructed to implement these continuing measures with utmost strictness. The objective is to prevent the AQI from deteriorating once again to the 'Severe' or 'Severe+' categories, ensuring that the recent gains in air quality aren't reversed. This layered approach allows for flexibility while maintaining a baseline of protective actions.

Strictures on Violating Construction Sites Remain

A specific directive has been issued regarding construction sites that were previously subjected to special prohibition orders due to violations of pollution control norms. These sites won't be permitted to resume operations under any circumstances without obtaining explicit special permission from the CAQM. This strict condition serves as a deterrent against non-compliance and ensures that past offenders are held accountable. It highlights the CAQM's resolve to tackle pollution sources rigorously, particularly those that have demonstrated a disregard for environmental regulations, while the emphasis is on ensuring that development activities proceed responsibly and sustainably.

A Prolonged Period of Poor Air Quality

The recent improvement comes after a challenging period for Delhi, which had been grappling with continuously poor air quality for an alarming 12 consecutive days. This extended duration of high pollution levels had caused significant health concerns and discomfort among residents. The daily fluctuations in AQI during this period underscored the volatile nature of air pollution in the region. The preliminary warning system for air quality in Delhi had also forecasted that the air quality could remain in the 'Severe' to 'Very Poor' categories for the subsequent five days, making the current improvement all the more welcome.

Understanding AQI Categories

To better comprehend the severity of air pollution, it's essential to understand the Air Quality Index (AQI) categories as defined by the Central Pollution Control Board (CPCB), while an AQI between 0 and 50 is considered 'Good', indicating minimal health impact. 'Satisfactory' ranges from 51 to 100, while 'Moderate' falls between 101 and 200. An AQI of 201-300 is classified as 'Poor', and 301-400 as. 'Very Poor', both of which can cause respiratory illness upon prolonged exposure. The 'Severe' category, from 401-500, affects healthy people and seriously impacts those with existing diseases. The 'Severe+' category, above 500, is an emergency situation, while delhi's recent AQI of 327 falls squarely in the 'Very Poor' category, indicating that while conditions have improved, they're still far from ideal.

Recent AQI Trends and Hotspots

Analysis of recent data from the Central Pollution Control Board (CPCB) reveals the fluctuating nature of Delhi's air quality. On Sunday, the average AQI was 391, followed by 370 on Saturday, 374 on Friday, 391 on Thursday, 392 on Wednesday, 374 on Tuesday, and 351 on Monday. These figures consistently placed Delhi's air quality in the 'Very Poor' category, often bordering on 'Severe', while the CPCB's Sameer app, which monitors 38 active stations, indicated that on Tuesday, only Rohini recorded an AQI of 401, placing it in the 'Severe' category. This was a significant improvement from Monday, when 15 stations had registered 'Severe' air.

Quality, highlighting the localized nature of pollution hotspots and the overall trend of improvement. While local emissions are a major contributor, stubble burning in neighboring states continues to play a role in Delhi-NCR's air pollution. Satellite imagery captured last Sunday revealed a total of 526 farm fire incidents across the region, while specifically, Punjab recorded 3 incidents, Haryana 1, and Uttar Pradesh accounted for a significant 522 incidents. Although these numbers might seem low compared to peak burning periods, even a limited number of farm fires can exacerbate the existing pollution load, especially under unfavorable meteorological conditions. The persistent issue of stubble burning necessitates continued efforts for its mitigation.

Delhi Experiences a Dip in Temperature

Adding another layer to the environmental narrative, Delhi experienced its coldest morning of the season on Wednesday, with the minimum temperature plummeting to eight degrees Celsius. This marked the lowest November temperature recorded since 2022. The India Meteorological Department (IMD) reported that Wednesday's minimum temperature was a notable 3. 3 degrees Celsius below the seasonal average, following Tuesday's minimum of nine degrees Celsius. Such a significant drop in temperature often coincides with increased pollution levels as colder air tends to trap pollutants closer to the ground, preventing their dispersion.

Historical Temperature Context

The IMD data provides a historical perspective on November temperatures in Delhi. Prior to Wednesday, the lowest temperature recorded in November this year was 8, while 7 degrees Celsius on November 17. In previous years, the lowest minimum temperature in November 2024 was 9. 5 degrees Celsius, while in 2023, it was 9. 2 degrees Celsius. The coldest November minimum temperature in recent years, however, was 7. 3 degrees Celsius, recorded in 2022. The weather department has also forecasted that the maximum temperature for the day is expected to hover between 24 and 26 degrees Celsius, indicating a clear and crisp day despite the morning chill. The interplay of dropping temperatures and air quality remains a critical aspect of Delhi's winter environment.