Pollution continued to be on the higher side in the capital, despite the government’s odd-even scheme in place.

On Tuesday, the levels of both PM10 and PM2.5 showed an upward trend since morning and the average air quality at around 7 pm was very close to the most polluted day recorded last year (December 23).

On the website of System of Air Quality and Weather Forecasting and Research (SAFAR), Particulate Matter (PM) 10 (particles below 10 microns in diameter) and PM 2.5 (below 2.5 microns and capable of entering human lung and blood tissues due to smaller size) were recorded at 422.7 and 278.4 microgram per cubic metre. The figures were close to the ones recorded on the most polluted day of the last year (PM 2.5 295).

Experts and the government blamed it on the weather conditions and said that the situation will likely improve later this week.

“On the first day of the odd-even scheme, the weather conditions were favourable and the pollutants got dispersed. Since Saturday, the situation is less favourable so there is more piling of pollution. But today we have some winds compared to last few days,” said Dr R K Jenamani, Head, IGIA MeT.

He added that the benefits of the favourable weather conditions, coupled with odd even scheme can be seen by later this week when pollution levels are likely to come down.

“The wind speed has considerably reduced from five-six kilometres per hour to almost 2-3 km per hour in the past one week. Also, the share of vehicles in overall pollution is less and there are other sources like industries, diesel generators, and open burning of bio mass fuel, besides metrological disturbances, which lead to a deterioration in air quality,” said Sumit Sharma, Fellow at TERI.

“The odd-even scheme is a good step but the small effect it might have on pollution gets mitigated due to meteorological factors and other sources,” he said.

However, the experts also said that had the odd-even scheme not been in place, the situation might have worsened.

“If you remove some vehicles from roads, there is some improvement in the immediate breathing zone. Had this scheme not been in place, the level of pollutants might have been higher,” said Vivek Chhattopadhyay of Centre for Science and Environment.

He also said that the government should monitor data after January 15 also to know the real impact of the experiment.

Meanwhile, the government on Tuesday said that the pollution on same days last year was less due to rain and it is comparing the present data with that of 2014.

“January 3, 4, and 5 last year saw rainfall and thus it would be unfair to compare the this year’s data with it. But, if we see the pollution levels in 2014 on the same days, we can come to a conclusion that currently PM 2.5 is much lower,” said Delhi Pollution Control Committee scientist M P Goerge.

The government also said that according to its live sampling the pollutants are showing a “definitive” declining trend across Delhi due to the odd-even scheme and the “impact of reduction in four wheelers on Delhi roads is clearly visible”.

“In 13 of these 20 locations monitored on Tuesday, the PM 2.5 level has been recorded at less than 300, which proves reduction in comparison to previous years at the same time by at least 100 units,” the government said in a statement.