'Pusa, Noida highly polluted post-Diwali'
The air pollution at Pusa in central Delhi and Noida in the National Capital Region (NCR) was highest in the region post-Diwali, scientists said Thursday. It was exorbitantly high on hourly scale from 11 p.m. Tuesday night to 1 a.m. Wednesday.
The data obtained by SAFAR (System of Air Quality Forecasting and Research) which is India's first air quality prediction system - consisting of eight automatic air quality monitoring stations - projected that there was a huge variability from one location to another location of Delhi and NCR on Diwali day.
The data by SAFAR revealed that most toxic pollutant PM2.5 (fine particulate matters of size less than 2.5 micrometres) level was 682 microgram/m3 at Pusa in central Delhi, which was higher than 372 microgram/m3 of 2011 and 652 microgram/m3 of 2010.
"The highest particulate pollution (PM2.5) level of around 682 microgram/m3 is observed at Pusa and Noida on Nov 13 which is just 90 percent increase from the reference background level of Nov 11 (Sunday), when weather was normal," Gufran Beig, programme director, SAFAR said.
The data also pointed out that the air pollution is 2.5 times higher than and "critical" and very unhealthy level of 253 microgram/m3 as defined in the scientific report on Air Quality Index (AQI) of Delhi published by Ministry of Earth Sciences in 2010.
Sunil Peshin, in-charge of SAFAR, Delhi said: "The least polluted region on Diwali day was found to be Palam, India Gate, Lodhi road and Aya Nagar where its level was recorded as 275 microgram /m3 which is almost half the pollution as compared to Pusa or Noida."
According to scientists high levels of air pollution at Pusa is due to the dense residential and high rise buildings where the pollution could not diffused.
However, scientists cautioned that not just on Diwali but even otherwise the air quality index limit is between "poor" to "very poor" category, which is not good either.
Apart from this, the scientists also noted that the pollution level on Diwali day (Oct 25) in 2011 was lower compared to 2012 because the festiwal was 19 days earlier.
"Last year the winter had not properly set and hence boundary layer was high and pollution got well mixed vertically up to quite high level as compared to current year. The minimum temperature was almost 3 to 4 degrees Celsius warmer than this year," the scientists said.
According to the experts, the emission level due to crackers could have been more or less of the same order but the weather condition played a very critical role.
"Although the emission levels of crackers were more or less the same, the meteorology played a very critical role in its distribution which is highly dominating this year. The westerly disturbances recently occurred this time prior to Diwali, but this was not the case last year," the scientists said.
Delhi was in the grip of smog from Oct 27 to Nov 8 due to drastic increase in fine particulate matter suspended over the city skies.
SAFAR has also forecast that the fine particulate matters level (of PM2.5 and PM10) has started to drop down and settle at around 250-300 microgram/m3.
"Delhiites can look forward to relatively better days ahead provided that the temperature does not fall further and some special extreme meteorological events do not appear, which is unlikely for now," Beig said.