The Capital has had cleaner air in the new year compared to the same period last year, weather monitors said.
The ministry of earth science’s System of Air Quality and Weather Forecasting and Research (SAFAR) attributed it to prevalent weather conditions that discouraged the accumulation of suspended particulates.
“The recent spell of rain has washed out the particulates. So, the city is enjoying the season’s best quality of air at this moment. January till now has been relatively better than last year,” said SAFAR project director, Gufran Beig.
A detailed study will be conducted later with the whole month’s data. “We have to wait till the end of January and analyse a larger series of data to assess the major reasons behind the relative improvement,” he said.
According to SAFAR, on Monday, the average readings of PM2.5 and PM10 were 101 and 179 micrograms per cubic metre, respectively.
The 24-hour prescribed standards of PM 2.5 and PM 10 are 60 and 100 respectively and prolonged exposure to anything beyond that harms the respiratory system, and may cause cardiac complications.
Beig, however, said the city may witness a build-up of pollutants in the coming days due to dipping temperature and calm wind movement.
The main factors that influence Delhi’s air quality are wind speed and direction. Typically in winter, the wind speeds are down making the air quality fouler.
Doctors advise people with heart or lung diseases, senior citizens, and children to remain indoors and maintain low activity when air quality index turns “severe” or records 400-plus levels of pollutants.
Delhi, a city of about 20 million people, is among the world’s most polluted cities according to the World Health Organisation. It has been struggling to clean up a toxic cocktail of dust, smoke and gases from its air.
In 2016, heavy smog enveloped the city for almost a week after Diwali in early November that plunged the city’s air quality to the season’s worst.
The Centre for Science and Environment (CSE) said it was the worst spell of smog in 17 years. The real-time readings of respirable pollutants PM2.5 and PM10 had breached the safe standards by over 17 times at many places.
The hourly AQI (air quality index) of monitoring stations run by CPCB and SAFAR had remained 500 plus, beyond the maximum limit.