The Ministry of Environment, Forest and Climate Change has recently placed a spotlight on the escalating issue of air pollution in Delhi. Data presented to the Lok Sabha highlights ozone as a primary pollutant—encompassing 95 days between 2016 and 2018— that contributes to the city’s deteriorating air quality. The extent of the ozone pollution was measured at 122 micrograms per cubic metre (ug/cu m), which is 1.22 times higher than the acceptable eight-hour average standard of 100 ug/cu m.
Duality of Ozone: The Good and The Bad
Ozone consists of three atoms of oxygen and can be found both in the Earth’s upper atmosphere—known as the stratosphere—and at ground level within the troposphere. Depending on its location, it can be either beneficial or damaging for humans and the environment.
The naturally occurring ozone in the Earth’s stratosphere forms a protective layer that shields us from the sun’s harmful ultraviolet rays. However, ozone depleting gases such as chlorofluorocarbons (CFCs), HCFCs, and halons can destroy this protective shield, leading to the creation of an ozone hole. As part of its efforts to protect this vital layer, India has adopted the Kigali Amendment, which aims to phase down hydrofluorocarbons.
In contrast, in the lower atmosphere, near ground level, ozone turns into a harmful air pollutant. It is created when pollutants emitted by vehicles, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight.
The Impact of Ozone Pollution
When the ozone descends to surface level, it wreaks havoc on both health and agricultural aspects. The ozone’s damaging impact can be seen in the destruction of crops and forests. On a health level, ozone can cause irritation in the respiratory system, leading to coughs, discomfort in the chest, and worsening of bronchitis, emphysema, and asthma. These can increase susceptibility to pulmonary inflammation like Chronic Obstructive Pulmonary Disease (COPD), negatively affect lung function, and make breathing difficult.
| Effects |
|---|
| Damage to crops and forests |
| Respiratory system irritation and disorders |
| Increased risk of pulmonary diseases |
Government Initiatives Against Ozone Pollution
In response to this growing issue, the government has enacted several measures to combat ozone pollution and improve overall air quality. This includes a shift towards BS-VI compliant vehicles from BS-IV, shutting down the polluting Badarpur thermal power plant, banning garbage burning, and implementing the Graded Response Action Plan (GRAP). In addition, the launch of the National Clean Air Programme (NCAP) and the setting up of a monitoring network for the assessment of ambient air quality at 779 locations covering 339 cities across 29 states and six Union territories round up the government’s action plan against ozone pollution.
