Surging Ozone Levels

Surging Ozone Levels

Subject: Environment

Section: Pollution

Context: Over the past week, the Central Pollution Control Board (CPCB) has identified ozone as a prominent pollutant in Delhi on June 2 and June 6.

Concept:

• Data from the Delhi Pollution Control Committee (DPCC) for May also indicates that ozone levels were well above the 8-hour standard of 100 µg/m3 and hourly standard of 180µg/m3 according to the National Ambient Air Quality Standards at different monitoring stations on multiple days.
• A recent analysis by the Centre for Science and Environment (CSE) noted that spatial spread of ozone in Delhi NCR began in March this year with early heatwaves. The analysis had stated that the geographical spread of ground-level ozone pollution in NCR in March and April this year was the highest in the past four years.
• Controlling vehicular pollution could be key to reducing the surge in ozone levels in the city that comes with the rise in temperature.

Ozone:

• Ozone is a secondary pollutant.
• It forms due to atmospheric reaction among nitrogen oxides and VOCs (volatile organic compounds) in the presence of sunlight.
• Nitrogen oxides that are emitted from vehicles are there in the atmosphere. VOCs are also present because of unburnt hydrocarbons. The VOCs energise nitrogen oxides in presence of sunlight to convert into ozone.
• Sunlight and high temperatures in summer contribute to increase in ozone formation.
• Ozone is not directly emitted from any source. The gases that come from vehicles, industries, power plants particularly nitrogen oxides and VOCs, under the influence of sunlight and temperature react to form ozone.
• To control ozone, there is a need to control precursor gases. Nitrogen oxide acts as catalyst and vehicles contribute the maximum to nitrogen oxide emission.
• Ozone is known to be a harmful gas for those who have respiratory conditions since it is highly reactive.

To know about National Ambient Air Quality Standards, kindly refer:    https://optimizeias.com/who-global-air-quality-norms/

Ground-level ozone can:

• Make it more difficult to breathe deeply and vigorously
• Cause shortness of breath and pain when taking a deep breath
• Cause coughing and sore or scratchy throat
• Inflame and damage the airways
• Aggravate lung diseases such as asthma, emphysema, and chronic bronchitis
• Increase the frequency of asthma attacks
• Make the lungs more susceptible to infection
• Continue to damage the lungs even when the symptoms have disappeared
• Cause chronic obstructive pulmonary disease (COPD)