Topics Covered: Conservation and pollution related issues.
What are Smog towers?
A smog tower is a structure designed to work as a large-scale air purifier.
How it works?
This structure fitted with multiple layers of filters which trap fine dust particles suspended in the air as it passes through them.
- Air is drawn through fans installed at the top of the tower, passed through filters, and then released near the ground.
Why in News?
Supreme Court, last year, had directed authorities to take measures, including asking the Delhi government and the Central Pollution Control Board (CPCB) to submit a comprehensive plan on setting up “smog towers” in the capital.
- Later, in January, the Court directed that two towers should be installed in the capital by April on a pilot project basis.
- This timeline was never met,
Are they helpful?
Yes, smog towers have been experimented with in recent years in cities in the Netherlands, China, South Korea and Poland. The first such tower was erected in 2015, in Rotterdam, Netherlands (it can filter 30,000 cubic metres of air per hour around it).
Experts have said that the towers would create “clean air zones” in the city. A tower would reduce 50% of the particulate matter load — fine dust particles suspended in the air — in an area of 1 kilometre in the direction of the wind, as well as 200 metres each along the sides of the tower and against the direction of the wind.
Why Delhi needs such measures?
Air pollution in the national capital has been an issue of concern for quite some time as Delhi and its suburbs have ranked among the most polluted cities in the world frequently since 2014, when the World Health Organisation (WHO) declared Delhi the most polluted city in the world.
- Pollution levels in Delhi increase dramatically during winter — on some days to nearly 10 times above the limits prescribed by WHO, posing a serious risk to vulnerable and also healthy populations.
Reasons behind high pollution levels?
- Construction work, industrial and vehicular pollution — in and around the city.
- The situation is aggravated at the start of winter by smoke from stubble-burning in northwestern states, coupled with unfavourable meteorological conditions, such as calm winds, low temperatures, and fewer sunny days.
Measures taken to control pollution:
- Persuading farmers in Punjab and Haryana to use mechanical alternatives to stubble-burning.
- Closure of thermal power stations in Delhi.
- Making industries use piped natural gas.
- Control measures taken under the Graded Response Action Plan (GRAP) when pollution levels spike.
- About National Clean Air Programme.
- Who releases the national air quality index?
- Composition and functions of the Central Pollution Control Board (CPCB).
- What is natural gas?
- Overview of the Graded Response Action Plan (GRAP).
Discuss the measures needed to reduce pollution levels in the National Capital.
Sources: Indian Express.