Delhi air quality was worst in March: Study

New Delhi, April 2 (IANS) Dust in the Delhi skies in March brought the air quality down to the worst levels in the last one year and the increase in total pollution was as high as that caused by Diwali fireworks, says a study.

The analysis of air pollution by the Indian Institute of Tropical Meteorology (IITM), Pune, during Feb 23-March 22 found that the level of particulate matter (PM 2.5) deteriorated from "moderate" to "very poor" around March 17.

As per the latest reading, the particulate matter level is coming down but is still 20-30 percent higher than normal.

The IITM monitors a wide range of pollutants from 10 different weather stations in the national capital region under the ministry of earth sciences project System of Air Quality Forecasting and Research (SAFAR).

Fine particulate matter (PM 2.5) are tiny particles in the air that reduce visibility and cause the air to appear hazy when levels are elevated. They are able to travel deeply into the respiratory tract, reaching the lungs.

"They (PM 2.5) do not reduce the visibility as badly as bigger aerosols (that is why common public could not feel it) but are highly dangerous for human health as they can penetrate deep into the lungs along with each breath you take," Gufran Beig, programme director, SAFAR, told IANS.

To add to the problem, the average level of coarser particles (PM 10) suddenly shot up to 800 ug/m3 from its background level of 200 ug/m3, recording an increase of 300 percent around March 20. These bigger particles swept away the tiny PM 2.5 particles and remained dominant until March 22.

"Any level beyond 420 ug/m3 in the air is considered as an emergency stage, categorised as very unhealthy by the technical report published by the ministry of earth sciences. This stage requires immediate necessary precursory measure to control as per WHO guidelines," said Beig.

The increase in total pollution was as high as pollution caused by fireworks during Diwali.

"But still the firework pollution is much more dangerous than this dust storm pollution because fireworks produce finer particles whereas dust storm increases the coarser particles comparatively," he said.

The India Meteorological Department attributed the increase in levels of fine and coarser particles in Delhi to the dust storm caused by southwesterly winds from Gujarat and Rajasthan.

Exposure to fine particles can cause health effects such as eye, nose, throat and lung irritation, coughing, sneezing, running nose and shortness of breath. Exposure to fine particles can also affect lung function and worsen medical conditions such as asthma and heart disease.

The increase in pollution also saw people complaining of respiratory and other problems.

"There was a layer of dust in the sky and it was so difficult to breathe. I had to take the nebulizer for five-six days to open my chest congestion caused by pollutants in the air," said Sadhna Gupta, a marketing professional.

(Richa Sharma can be contacted at richa.s@ians.in)