Delhi's air quality slightly dips with change in wind direction

Delhi's air quality slightly dipped on Wednesday due to change in the direction of wind, now flowing from the polluted Indo-Gangetic plains, authorities said.

The air quality slipped from satisfactory to moderate category due to reversal of wind direction which has now started flowing from the polluted Indo-Gangetic plains, said Gufran Beig, Project Director at the central government-run System of Air Quality and Weather Forecasting and Research (SAFAR).

"This happens every year when the wind direction changes," Beig said, adding that polluted wind combined with internal polluting factors in Delhi lead to a drop in air quality.

An overall air quality index (AQI) of 140 was recorded at 4 pm on Wednesday which in the moderate category. On Tuesday the air quality in the national capital was in the satisfactory category.

An AQI between 0-50 is considered Good, 51-100 Satisfactory, 101-200 Moderate, 201-300 Poor, 301-400 Very Poor, and 401-500 Severe.

The PM10 level (presence of particles with diameter less than 10mm) was at 179 in Delhi-NCR and 178 in Delhi on Wednesday, according to data by the Central Pollution Control Board. The PM2.5 level in Delhi-NCR was 64 and in Delhi was 59.