LUCKNOW: Summer pollution curve has taken an ugly turn as ground-level ozone, a highly reactive and harmful gas, far exceeds the permissible limit. With heat wave raging in early June ozone has peaked to dangerous levels. Rising NOx levels and volatile gases in the air, primarily from vehicles, form the recipe for ozone when exposed to intense sunlight and high temperature.
Ozone is a serious threat to those suffering from asthma and respiratory problems and can cause premature deaths if it is high even for a short duration during the day. Delhi has witnessed a significant ozone build-up this summer, says a latest analysis done byCentre for Science and Environment (CSE).
A study of the real-time air quality data available from the key monitoring locations of the Delhi Pollution Control Committee (DPCC) for the period January to early June 2014, shows rapid build-up of ozone and more frequent violation of standards this summer. CSE cautions Delhi needs to act fast to reduce the cocktail of gases that are forming ozone in the air. Its government must fast track pollution alert system and next generation air pollution control measures, says CSE.
CSE experts saywarmer temperatures and the extreme heat waves are threatening to increase the frequency of days with unhealthy levels of ozone - with serious public health consequences.
Ground-level ozone is not directly emitted by any source. This is formed when oxides of nitrogen (NO X) and a range of volatile gases, primarily from vehicles and other sources are exposed to each other in sunlight. Warm and stagnant air increases the formation of ozone, which is known to be extremely hazardous for human health.
According to Anumita Roychowdhury, executive director, research and advocacy and head of CSE's air pollution programme, "Ozone is the new generation public health threat and a difficult challenge. It must be curbed at the early stages with stringent controls on nitrogen oxide (NOx) and toxic and volatile gases, the major ingredients of ozone recipe."
Ozone is an extremely harmful gas, particularly for those involved in outdoor activities. Just a few hours of exposure to it can trigger serious health problems, especially among those who are already suffering from respiratory and asthmatic problems. 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. It can even worsen heart disease, bronchitis and emphysema.
Ozone is included in the daily smog and health alert programmes in countries such as Mexico, the US and China. Roychowdhury says, "Explosive increase in vehicle numbers, especially diesel vehicles that spew much higher levels of NOx and volatile organic compounds, can only worsen the deadly recipe needed for formation of ozone in the city with hot and extreme climate."
The body said that the city government must prevent this trend by making serious efforts to control NOx and volatile organic compounds that largely come from vehicles. It must make efforts to reduce numbers of vehicles, especially diesel ones. The city government can also introduce a daily health alert system to inform the sensitive population about the high daily levels and enforce emergency pollution control measures such as reducing traffic volume, etc.
