Delhi Air Quality

Delhi had the cleanest air in the past five years, but that changed rapidly as air quality deteriorated, reaching the ‘very poor’ category with an Air Quality Index (AQI) of 379 on Monday. This prompted the reintroduction of anti-pollution measures, such as a ban on certain vehicles and mandatory hybrid mode for junior classes. The air quality is expected to decline further, potentially hitting the ‘severe’ category by Tuesday.

Also Read: Delhi Suffocates Under Smog, Air Quality Dips to ‘Very Poor’

What Caused the Sudden Drop in Air Quality?

Several factors have led to the drop in Delhi's air quality, including weather conditions and ongoing pollution from various sources.

1. Low Wind Speed Traps Pollutants

Calm winds and cooler temperatures have significantly contributed to trapping pollutants in the air. As temperatures fall, the altitude at which pollutants can disperse decreases, resulting in a buildup of harmful particles. The India Meteorological Department (IMD) reported wind speeds below 6 km/h on Monday, exacerbating the situation. This trend is expected to persist, with low wind speeds forecasted for the rest of the week.

2. Cold Wave Conditions

Delhi is also facing an early cold wave, with temperatures dropping below 5°C. The first cold wave of the season was recorded on December 11, marking the earliest occurrence since 1996. These chilly temperatures, combined with low wind speeds, further trap pollutants, worsening air quality. The IMD anticipates that cold wave conditions will last until at least Wednesday.

3. Transport and Other Emissions

The transport sector remains a significant contributor to Delhi's pollution, accounting for nearly 17% of the city's particulate matter pollution. Industrial emissions also play a crucial role, adding to the overall pollution levels. These issues continue to be a concern even as Stage II of the Graded Response Action Plan (GRAP) is in effect.

4. Lack of Significant Rainfall

While a brief drizzle on December 9 helped clear some pollutants, the city has not seen any substantial rainfall since then.

Also Read: Delhi air quality worsens; CAQM to put a halt on the national capital and impose GRAP 4 restrictions

With no immediate relief in sight, Delhi's air quality is expected to remain poor, with severe health risks for vulnerable groups. The authorities continue to monitor the situation closely and have implemented necessary measures to curb pollution levels.

With inputs from agencies
Image Source: Multiple agencies