The arrival of the president of the United States Barack Obama at the capital was marked by heavy fog early on Sunday with temperatures dipping and particulate pollution much above safe limits. Though showers on Thursday and Friday last week reduced pollution from 'severe' level to 'poor' level, the particulate matter pollution did not settle down. Real-time air quality data from multiple government agencies showed, that as the motorcade of president Obama advanced from Palam airport to ITC Maurya, the key parameters of PM 2.5 (particles smaller than 2.5 micrometers) was double the safe limit. At Mandir Marg, the nitrogen oxide levels at the same time were between 50 and 70 micrograms/cubic metre (ug/m3) while the permissible limit is 80 ug/m3.
The Delhi Pollution Control Committee's ambient air quality monitoring indicated that at RK Puram, PM10 levels (particles smaller than 10 micrometers) were 208 ug/m3, double than the permissible limit of 100ug/m3 while PM2.5 was 159ug/m3, almost three times more than permissible limits. Even the United States Embassy monitors ambient air quality and recorded an 'unhealthy' PM2.5 levels ranging from 150 to 180 throughout the day. Converted to the parameters of the Central Pollution Control Board, it was almost double the permissible limits. The pollution levels in the capital have been a reason for worry ahead of President Obama's visit as the chief guest at India's Republic Day parade and according to the India Meteorological Department (IMD) and other experts, the air would continue to be polluted unless it rains on Monday. The IMD on Sunday morning had forecasted rains for Monday but by Sunday evening, it had changed its forecast to 'fog'.
Experts told dna that the thundershowers last week have helped to significantly reduce the particulate matter pollution but on Monday, Republic Day, foggy conditions could deteriorate air quality. "The air quality levels were very severe last week and even today they were in the range of moderate to poor. Unless it rains on Monday, conditions would be smoggy," said Gufran Beig, project director, System of Air Quality Weather Forecasting and Research, an initiative of Ministry of Earth Sciences and Indian Institute of Tropical Meteorology, Pune.
