CSE study says ozone levels alarming, seeks urgent steps

The level of ozone has shot up to alarming levels in the city and the National Capital Region (NCR), a latest analysis by the Centre for Science and Environment (CSE) has revealed.

“Increased heat wave and rising summer temperatures are worsening the situation,” said Anumita Roychowdhury, CSE’s executive director (research and advocacy).

Experts in the CSE claimed that this is bad news for those suffering from asthma and respiratory problems. It is dangerous if ozone increases even for a short duration. Urgent steps are needed, it said.

“An earlier study by a US-based organisation said early deaths due to ozone have jumped by 148% in India. Ozone aggravates respiratory problems, especially chronic obstructive pulmonary disease (COPD),” she added, even as specific data for Delhi has not been recorded yet.

Ozone is an extremely harmful gas, just a few hours of exposure to it can trigger serious health problems. It is particularly harmful for outdoor activities. Ozone worsens symptoms of asthma, leads to lung function impairment and damages lung tissues. Chest pain, coughing, nausea, headaches and chest congestion are common symptoms.

CSE has analysed the real-time air quality data available from the key monitoring locations of Delhi Pollution Control Committee for the summer months of 2016 and 2017. This shows ozone pollution in the city has been worsening with the onset of summer.

The analysis shows heat waves and sunshine have increased the frequency of days with unhealthy levels of ozone. This has become worse this summer.

“Ground-level ozone is not directly emitted by any source. This is formed when oxides of nitrogen (NOX) and a range of volatile gases, primarily from vehicles and other sources, are exposed to each other in sunlight.

For example, in April 2017, as the temperature increased from 27°C on April 9 to 32°C on April 14, the daytime ozone levels increased by 134% or 2.34 times — rising from 90 to 211 microgramme per cubic metre.