The level of pollution remained above the permissible limits but was comparatively less compared to the contamination levels recorded in the previous years on the occasion of Deepawali.
Officials of the Uttarakhand Environment Protection and Pollution Control Board (UEPPCB) said that the quantum of Nitrogen Oxides and Respirable Suspended Particulate Matter (RSPM) in the air increased as compared to the usual level in Dehradun.
The regional officer SS Rana, UEPPCB said on Monday that in the past four years, there has been an increase in Respirable Suspended Particulate Matter (RSPM), level of Sulphur Dioxide and Nitrogen Dioxide as compared to the normal RSPM (100), and Sulphur Dioxide and Nitrogen Dioxide (80) over the past 24 hours in the city.
On normal day (October 24, 2016), RSPM was recorded at 175.54 at Clock Tower while 194.41 at Raipur Road and 179.16 at Nehru Colony.
Sulphur Dioxide at the Clock Tower was recorded at 24.85 while 25.52 at Raipur Road and 23.54 at Nehru Colony accordingly while
Nitrogen Dioxide at Clock Tower was reported 27.48 while 26.3 at Raipur Road and 25.12 at Nehru Colony.
He further said that RSPM machine had been installed at Clock Tower, Raipur Road and Nehru Colony to measure air ambient quality standard. “A marginal increase was observed in respect of the levels of the chemicals in the air. This could be attributed to use of fire crackers besides increased vehicular movement during the Diwali celebration. The increase in pollutant levels observed on Deepawali night could also be due to weather conditions, like early onset of winter,” he said.
On Deepawali day, pollution level was recorded higher at Nehru Colony than Raipur Road and Clock Tower. Report revealed that on October 30, 2016, RSPM was recorded at 240 at Clock Tower while 253.12 at Raipur Road and 369.9 at Nehru Colony.
Sulphur Dioxide at Clock Tower was recorded at 26.51 while 26.91 at Raipur Road and 28.29 at Nehru Colony.
Nitrogen Dioxide at Clock Tower was reported 29.45 while 30.23 at Raipur Road and 31.01 at Nehru Colony.
According to the National Ambient Air Quality Standard, 100 micrograms per cubic meter is moderate. “RSPM higher than that is critical,” Rana added.