Air quality to oscillate between poor to very poor
- Delhi’s air quality deteriorated from ‘moderate’ to ‘poor’ and ‘very poor’ on April 29.
- It will be oscillating between ‘poor’ and ‘very poor’ for the next three days, according to the SAFAR-System of Air Quality and Weather Forecasting and Research.
- Delhi’s air typically worsens in October-November and improves by March-April.
What is the cause
- Current weather conditions are not unfavourable, unlike in winter.
- Hence, apart from local emissions, the deterioration in air quality is being attributed to an increase in fire counts, mostly due to burning of wheat crop stubble in northern India.
- Deteriorating air quality is worrying amid an increasing number of novel coronavirus disease (COVID-19) and deaths.
Quality classification
- An AQI between 0-50 is considered ‘good.
- An AQI between 51-100 is considered satisfactory.
- An AQI between 101-200 is considered moderate.
- An AQI between 201-300 is considered poor.
- An AQI between 301-400 is considered very poor.
- An AQI between 401-500 is considered severe.
- Above 500 is the ‘severe-plus’ or ‘emergency’ category.
