: Delhi’s pollution levels may not come under control even if all the measures recommended by a report commissioned by the State government are implemented across the National Capital Region.
This comes at a time when the Aam Aadmi Party (AAP) government has rolled out round two of the odd-even road-rationing scheme.The report by the Indian Institute of Technology-Kanpur, titled ‘Comprehensive Study on Air Pollution and Green House Gases (GHGs) in Delhi’, was commissioned by the Delhi government in 2013 and submitted in January this year.
After months of delay, the Environment Department has recently made the report public. The study found that levels of pollutants – particulate matter, sulphates and nitrates – in Delhi and in the NCR were “similar and comparable”.
On an average, Delhi sees a PM2.5 level of 335 micrograms per cubic metre, which is almost six times the standard of 60. If Delhi enacted all the control measures suggested by the report, the PM2.5 level would reduce by 65 per cent, which would still make it around double the permissible level. So, the report makes the case for implementing similar measures across the NCR. While this would reduce the PM2.5 level by 78 per cent, it would still be slightly higher than the permitted level.
Experts have been recommending a regional action plan for the NCR for years. In China, the government implemented national as well as regional-level action plans in September 2013. Reports have found that this approach has started showing results.
For Delhi, the IIT-Kanpur report has suggested various air pollution control options and evaluated their effectiveness in improving air quality. Several sources contribute to the dominant pollutants - PM2.5, PM10 and NO2 - in ambient air. Measures have been suggested for 12 major sources.
Around 9,000 hotels or restaurants in Delhi use coal, mostly in tandoors. A shift to electric or gas-based appliances has been suggested. For construction and demolition, which is a consistent source throughout the year, among the steps proposed are proper disposal of waste, appropriate handling and storage of raw material, and covering the site with a fine screen. For road dust, which is the largest source of particulate matter in the summer, mechanical and vacuum assisted sweeping has been suggested at a frequency of four times a month. Drastic reduction in PM10 has been estimated with sweeping alone.
Diesel vehicles have a significant contribution towards all pollutants. The report recommends that sulphur content in diesel should be brought down to 10 parts per million or less by end of 2018, electric and hybrid vehicles be introduced and diesel vehicles be equipped with Diesel Particulate Filter (which have PM emission reduction efficiency of 60-90 per cent). If implemented as scheduled, these three measures alone will cut down vehicular emissions by half.
Secondary particles, the major and consistent source of PM in Delhi, originate from sulphate (SO2) and nitrate (NOx) gases. Controlling these gaseous pollutants from the 13 major thermal power plants lying within the radius of 300 km from Delhi will have a huge impact on air quality. Sulphate removal technologies like wet flue gas desulfurisation have been suggested among other measures.
