Delhi has been witnessing an unprecedented ozone build-up this summer, says a latest analysis done by Centre for Science and Environment (CSE). Nearly every day in the month of April, ozone levels have exceeded the standards proposed by the Union Ministry of Environment and Forests.
According to the researchers behind this analysis, the ozone build-up is the result of a deadly combination of high pollution levels and an unusually hot and sunny summer. Ozone is known to be extremely hazardous for human health.
According to Anumita Roychowdhury, Associate Director, CSE and head of the Centre’s air pollution unit, “ozone is not emitted directly from any source. Other pollutants, primarily nitrogen oxides (NOx) and hydrocarbons that are spewed by the growing number of vehicles and other sources in the city, react in the atmosphere under the influence of sunlight and high temperature to form ozone.”
“When ambient temperatures and sunlight remain high for several days -- as it has happened this summer -- and the air is relatively stagnant, ozone builds up fast,” she adds.
CSE analysed the ozone data generated by the Central Pollution Control Board in its three automatic monitoring stations in Delhi – Siri Fort, the ITO traffic intersection and the Delhi College of Engineering (DCE) in
Bawana -- from January till May 17, 2009.
The data was assessed in relation to the proposed ozone standards in India.