TAG: GS 3: ECOLOGY AND ENVIRONMENT
THE CONTEXT: Recently, the Delhi-NCR recorded the most intense & prolonged ozone pollution, presenting a new urban crisis in India.
EXPLANATION:
- Recent findings from the Delhi-based think tank Centre for Science and Environment (CSE) paint a stark picture.
- Ground-level ozone concentration has surged across 10 major cities: Delhi-NCR, Mumbai-MMR, Kolkata-KMA, Hyderabad, Bengaluru, Chennai, Pune, Ahmedabad, Lucknow and Jaipur.
- The data reveals an alarming trend and highlights the urgent need for action.
Ozone Pollution
- Unlike some pollutants that are directly emitted, ground-level ozone is formed through complex reactions involving nitrogen oxides and volatile organic compounds in the presence of sunlight.
- These precursors come from various sources, including vehicle exhausts, industrial emissions and even natural elements like plants.
- Once ozone is formed, it poses severe health risks, particularly for those with respiratory conditions, children and the elderly.
- It inflames and damages airways, exacerbates asthma and can lead to chronic respiratory diseases.
Delhi-NCR: Most affected
- Delhi-NCR is experiencing the brunt of this issue, with a staggering 176 days of ground-level ozone exceedances recorded between April and July 2024.
- Furthermore, the duration of ozone exceedance was notably prolonged, with Delhi experiencing exceedance on average for about 13 hours per day.
- The frequency and intensity of ozone pollution in Delhi underscore the urgent need for enhanced monitoring and stricter regulatory measures to address this escalating public health threat.
Mumbai-MMR & Pune: Growing concern
- Mumbai-MMR and Pune are also grappling with the rise in ground-level ozone, each recording 138 days of exceedance.
- Mumbai, with its complex pollution landscape, now faces a new challenge as ozone levels climb.
- Pune, known for its rapid urban growth, is witnessing a concerning increase in ozone pollution with the duration of exceedance in Pune averaging about 15.1 hours per day, reflecting prolonged periods of elevated ozone levels.
Jaipur: Rising to new heights
- Jaipur’s situation is particularly alarming.
- The city reported 126 days of exceedance, with an average ozone level of 81.2 µg / m³, peaking at 205.9 µg / m³ during the summer.
- This peak concentration is the highest among the cities studied, highlighting the severe nature of the problem in Jaipur.
- The high levels of ozone present a critical public health challenge for the city.
Hyderabad and Bengaluru: Shift in patterns
- While Hyderabad and Bengaluru have fewer exceedance days compared to Delhi-NCR and Mumbai-MMR, they are experiencing a troubling rise in ozone
- Hyderabad recorded 86 days of exceedance, while Bengaluru had 59 exceedance days.
- Despite lower peak levels, both cities faced persistent ozone pollution, with exceedances lasting an average of 13 hours per day in Hyderabad and 12 hours per day in Bengaluru.
- This upward trend signals a growing concern in these cities, which have traditionally been less affected by ground-level ozone pollution.
Chennai & Ahmedabad: Significant increases in smaller cities
- Chennai, with only nine days of exceedance, seems relatively less impacted.
- However, its peak ozone level of 192.7 µg / m³ indicates that when exceedances occur, they are severe.
- Ahmedabad, though smaller, has experienced a dramatic 4,000 per cent increase in exceedance days, mirroring broader urban pollution trends with duration of exceedance averaging about 14.2 hours per day.
- This surge underscores the rising challenge even in less populous cities.
Lucknow & Kolkata-KMA: Varied Trends
- Lucknow and Kolkata-KMA exhibit distinct patterns of ground-level ozone pollution.
- Lucknow reported 49 days of ozone exceedance with a peak level of 179.1 µg / m³.
- Although Kolkata-KMA experienced a higher number of exceedance days, totaling 63, both cities have shown a slight decrease in exceedance days compared to previous years.
- Despite this reduction, the issue remains pressing. In Lucknow, the duration of exceedance averaged around 15.7 hours per day, the highest among the metropolitan areas studied, highlighting the severity of the problem.
- Kolkata, with an average exceedance duration of about 12 hours per day, also demonstrates significant ozone pollution.
Year-round problem
- Ground-level ozone is not just a seasonal problem.
- While summer months see spikes, ozone pollution persists throughout the year.
- Night-time exceedances are particularly troubling, with cities like Mumbai-MMR, Delhi-NCR and Pune recording high ozone levels well into the night.
- This persistent pollution indicates a continuous challenge rather than a temporary issue.
- The data from these 10 cities highlight a critical and expanding issue with ground-level ozone.
- Addressing this pollutant requires a comprehensive strategy that integrates it into air quality management and develops effective public health responses.
- As urban areas continue to grow, tackling ground-level ozone will be essential for protecting public health and improving overall air quality.
- The time for action is now — before this invisible menace becomes an even more serious threat.
