Weather

Environment scientists, however, said this slight drop in the pollution could be temporary as it was due to the rain, and the pollution will remain in the “poor” or “very poor” category at least till May 16 due to the recurrent dust storms.

Ghaziabad on Monday was the most polluted city in the country with an Air Quality Index (AQI) of 384 as per the CPCB data. Neighbouring Noida was the second most polluted city with AQI value of 347. Officials from East Delhi Municipal Corporation, New Delhi Municipal Council and public works department said they have been sprinkling water, covering construction sites, mechanically sweeping roads regularly to combat dust pollution, but pollution levels don’t reflect these actions.

Poor air quality in Delhi has been aggravated by westerly winds bringing dust from neighbouring Rajasthan and Haryana and below-normal pre-monsoon showers in northwestern India, leading to extremely dry and dusty conditions. Pre-monsoon rainfall between March 1 to May 8 over northwest India is 37% below the long-period average, according to data released by the India Meteorological Department (IMD).

Minutes of the meeting held by the task force on the graded response action plan (GRAP) on May 8 show that it was briefed about a sudden rise in particulate matter concentration in DelhiNCR to “very poor” category and further, moving towards the “severe” category as a result of a fresh plume of dust emitted from western Rajasthan and northern Gujarat reaching Delhi on May 8.

The task force recommended that agencies intensify efforts to control dust from various sources such as construction and demolition sites, handling of construction material waste, roads, stone crushers, and ready mix concrete plants.

The task force also advised public to minimise prolonged exposure to high air pollution levels outdoor. “GRAP is already being implemented. The main source for a spike is dust which is being transported from nearby areas and even generated locally. The weather conditions are ideal for re-suspension,” said VK Shukla, head of CPCB’S air quality lab in Delhi. Re-suspension refers to dust from local sources continuing to be suspended in the air as opposed to settling.

Air quality has been exacerbated by forest fires in various districts of Uttarakhand over the past week. The state recorded the highest number of forest fires in the past week with about 4,000 fires detected through satellite images by the Forest Survey of India (FSI). “There is a sudden spike in forest fires now because the weather conditions are ideal. Till two weeks back, there was moisture in the soil because of some thunderstorm activity. It has been dry and hot since,” said a FSI official on condition of anonymity. Almora, Pauri Garhwal and Nainital are the worst affected districts , according to FSI data.

Wheat stubble has also been burnt in various parts of Punjab and Haryana since May 1, though the extent of crop stubble burning is far lower than paddy stubble burning which takes place in September. “Only 40% of the farms in Punjab may have set fire to wheat