The mercury in the National Capital Region (NCR) is rising earlier than normal this year and vehicles are blocking roads, increasing the level of ground-level ozone, a highly reactive gas that is particularly vulnerable to people suffering from asthma and respiratory conditions. Can be dangerous, continues. Delhi Pollution Control Committee (DPCC) data shows that many places across the city have increased and already violated permissible norms.
Gas formation results from a mixture of heat and gases such as oxides of nitrogen and volatile organic compounds, largely during the day in areas where there is traffic congestion or the presence of many industries.
According to DPCC data for the last week of April (April 24-30), the temperature in parts of Delhi reached 43-47 °C (as against the normal average of 38 °C during this period), with places like Jawahar Lal Nehru (JLN) Stadium, Dr Karni Singh Shooting Range, Nehru Nagar, Mandir Marg, RK Puram and Narela all violated the eight-hour ozone limit of 100 micrograms per cubic meter on six of the seven days. In the busy industrial area of ​​Mundka, it crossed the eight-hour limit on five of the seven days, while on Aurobindo Marg, where traffic congestion is an issue, it failed to meet the standards on three of the seven days .
During this period, the highest eight-hour value was recorded at JLN Stadium, where it touched 199.8 µg/m3, followed by Dr Karni Singh Shooting Range (188.4) – both almost twice the safe limit.
Unlike the 24-hour standards PM2.5, PM 10 or NO2, ozone levels are measured by eight-hour standards and one-hour standards, mainly because of how dangerous the gas can be in a short period of time. While the eight-hour standard of ozone is 100 micrograms per cubic meter, the hourly standard is 180 micrograms per cubic meter.
DPCC data shows that hourly gas prices at JLN Stadium reached 251 micrograms per cubic meter every day during the last week of April, around noon, when there is substantial traffic and temperatures are high. In Nehru Nagar, next to Lajpat Nagar, it reached 238 micrograms per cubic metre, mainly due to traffic.
According to experts, while the levels of PM2.5 (particulate matter with a diameter of 2.5 micrometers) and PM10 (suspended coarse particulate matter, either solid or liquid, with a diameter of 10 micrometers or less) may be low, dangerous The gases can still pollute. In common with the air, ozone had become the major pollutant in those days.
“Ozone levels are highest on days when there are clear skies, and if particulate matter levels are low, the Sun’s heat penetrates deep into the atmosphere, reacting with oxides of nitrogen to form ozone. It is,” said Dipankar Saha, former chief. Air Laboratory of Central Pollution Control Board. He said ozone levels are likely to rise further in May and June, when summer is at its peak.
A study by the Center for Science and Environment (CSE) last year found that high levels of ozone have become a year-round problem for Delhi – especially during summers.
Tanushree Ganguly, Program Lead, Council on Energy, Environment and Water (CEEW) said that since vehicular emissions are a significant source of NOx, there is a need to focus on the vehicular sector to reduce ozone levels, which will help will also. Particulate matter reduction.
“The ozone levels have exceeded the permissible 180 micrograms per cubic meter in the last few days at many places including Anand Vihar, Ashok Vihar, Chandni Chowk, Patparganj, Narela and Jahangirpuri,” Ganguly said.
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