With increasing temperatures, toxic ozone levels, which cause a number of health problems especially for those suffering from asthma, have breached the permissible limits here, the Meteorological Department said on Thursday.
The level of toxic ozone in the Capital was highest this year during the past two weeks, when the maximum temperatures hovered above 40 degrees Celsius. Surface ozone increases due to high temperatures coupled with high levels of carbon monoxide and nitrogen oxide.
Normally, Delhi’s air quality problem mainly occurs due to particulate matters like dust, dirt or smoke, and not so much due to gaseous pollutants, unlike in the western countries, where surface ozone pollution is a major issue.
“In some areas of Delhi NCT, surface ozone [eight sunlit hour average] touched as high as 120 ppb [part per Billion], which is classified as poor in the Air Quality Index,” said System of Air Quality and Weather Forecasting Research (SAFAR) project director Gufran Beig.
The permissible limit is 50 ppb (eight hour day average).
SAFAR, which facilitates information on air quality, weather and radiation (ultraviolet index), operates under the aegis of the Indian Institute of Tropical Meteorology (IITM), an autonomous body under the Ministry of Earth Sciences.
“There is huge variability from one location to another within Delhi among the 10 SAFAR stations, which is understandable as NOx [nitrogen oxide] levels are highly variable along with CO [carbon monoxide],” Mr. Beig said.— PTI
