It may not have been on the side of the Delhi government and its odd-even restriction on Friday but the weather ensured lower levels of pollution in the city on Saturday.
High winds, low humidity and a relatively lower number of cars on the roads on the second day of the implementation of the plan – which aims to clean Delhi’s toxic air – gave Delhi better air quality than Friday. The levels, however, were still several times over the safe limit.
Scientists, including those working with the Delhi government, said that a deeper analysis of the impact of odd-even restrictions would require data collected over at least four days.
According to the data from the SAFAR air quality index, the hourly average graph of mass concentration of pollutants did not show any upward trend after 2pm as it had on Friday. It ranged around 190 micrograms per cubic metre till 6 pm. As per Indian standards, air quality is ‘very poor’ when particulate matter ranges between 120 and 250 and anything above that falls in the ‘severe’ category.
According to experts, wind is the single biggest factor in determining air pollution levels at any given time.
“Wind will affect local pollution irrespective of source changes. Stronger winds sweep away many pollutants while light winds or no winds hardly remove it,” said RK Jenamani, director in charge, IGI Met Centre.
While air quality on Friday was worse than both Thursday and Saturday, Delhi Pollution Control Committee said that air quality data from 24 locations showed encouraging results of reduction in air pollution in Delhi on the New Year Day.
“The first results of ambient air data collected by mobile units of the Delhi Pollution Control Committee on 24 locations across Delhi on the New Year Day show an encouraging trend of reduction in air pollution in both PM 2.5 and PM10 categories. PM 2.5 microgram per meter cube measured in 24 locations ranged between 121 and 226 on Friday. On an average, PM 2.5 hovered around 250 across the national capital in previous years on the same date. PM 10 microgram per meter cube measured in 24 locations was in the range of 149-503. On an average, PM10 was measured between 400-500 across Delhi in previous years at this time and date,” a statement issued by DPCC said.