What makes Delhi’s air the worst in the world?
2 min read . Updated: 20 Feb 2015, 01:30 AM IST
PremiumMain air quality issue for Delhi arises from high levels of particulate pollutants PM10, PM2.5 and black carbon
New Delhi: Emissions in Delhi have been progressively rising since 2010 as has the contribution of the transportation sector to the city’s air pollution, according to a study by the Indian Institute of Tropical Meteorology (IITM).
The main air quality issue for Delhi lies in particulate pollutants namely PM10 (with a size of 10 micron), PM2.5 (2.5 micron) and black carbon.
While particulate matter can settle deep inside the lungs, making people vulnerable to cardiovascular and respiratory diseases, black carbon plays an important role in climate change, too.
In 2014, a World Health Organization study in May and Yale study in February found the air in New Delhi to be the most polluted.
There were 12 other cities in the top 20 most polluted cities among 1,600 studied cities.
The rise in the number of vehicles has led to emissions from the transport sector growing by more than 30% between 2010 and 2014, accompanied by a marginal increase of around 5% due to rise in traffic density in terms of dust as vehicles go on unpaved roads.
Unpaved roads and construction work result in a spike in PM10 emissions.
Emissions from bio-fuel have decreased by 1-3% even though biomass burning has seen a slight increase.
To develop the emission inventory for PM2.5, PM10, and BC, IITM divided the sources into five sectors: transport (petrol, diesel, CNG), bio-fuel (cooking-wood, coal, kerosene, open bio-mass), power (coal burning in thermal power plants), industry, and others (paved, unpaved roads, construction activities, brick kiln, wind blown). The growth rate for PM10 was around 7% over the past four years; the major growth share is from transport sector. The total emission of PM2.5 has seen a rise of 11.5% in this period.
“Contribution of various sources of emissions, along with the high number of cooler days lead to heavy pollution in Delhi," said Gufran Beig, project director, System of Air Quality Weather Forecasting and Research which monitors air quality under ministry of earth sciences.
“The pollution concentration multiplies when the aerosols sit on fog."
The air is the worst in Connaught Place, Parliament House, India Gate, Indira Gandhi International Airport, Okhla Industrial Area, Pragati Maidan, IP Estate, Janakpuri, Meharuli, and Laxmi Nagar.
“The government needs to tackle the problem of air pollution with short-term, medium-term and long-term measures. Health advisories on a daily basis is good as a short-term measure, but we need to look at long-term strategies like emission management, and improving public transportation and connectivity," said Vivek Chattpadhyay, programme manager, clean air programme, Centre for Science and Environment.
