The Delhi Government is claiming that air pollution has reduced by 30 per cent due to a fewer number of vehicles on Delhi roads during the trial run of the odd-even scheme since January 1.
However, the data collected by the Government was barely a 20-minute observation of 17 to 25 different locations in the national Capital at different times on different days.
No wonder, the data analysis of the Delhi Government shows that the level of particulate matter-2.5 (PM2.5) has reduced by up to 100 µg/m3 in the inner circle of the city. On the contrary, their own data also reveals that in heavy traffic congestion areas, mainly border areas, no radical pollution drop has been measured.
Moreover, the ambient air monitors of the Delhi Pollution Control Committee (DPCC) in the city, which are placed at the different five locations, illustrated that no significant drop has been observed during odd-even scheme.
On Friday, the Delhi Government released an analytical report on air quality during the first week of the implementation of the scheme prepared by the Supreme Court-appointed Environment Pollution Control Authority (EPCA).
On the basis of air quality data of November, December (2015) and till January 7, derived from the DPCC by the Centre for Science and Environment (CSE), the report has claimed that radical drop in the concentrations of pollutants was measured in the first week of January. Also, the report claimed that concentration level of noxious pollutants is higher in this winter as compared to the level of pollutant during the last winter. The EPCA based its findings on the pollution committee data analysed by the CSE data.
Describing freak weather pattern as the reason for rising pollutants in air, EPCA report also stated that current weather conditions in Delhi are at emergency levels. “The Western Disturbance has brought moisture, which traps pollutants but this combined with near still and no-wind conditions means conditions are very bad for air quality. Similar weather conditions - with less severe conditions of no-wind and moisture had lead to peaks of pollution that are alarming and hazardous for health,” said the report.
It further stated odd-even scheme, which has reduced the traffic volume, has managed to bring down the peak level of pollution in the city to its “lowest”. November and December 2015 showed higher number of days in severe category — four times the safe standard — which is the worst category according to the National Air Quality Index.
“This brings out the clear impact of the odd-even scheme on the pollution levels. Even when wind was not there to blow it away, the scheme succeeded in arresting the upward trend… The scheme is designed for immediate relief as it takes almost half the private cars off the roads, which contribute to pollution from their tailpipe...This is needed to protect public health in a city where every third child has impaired lungs,” it said.
Vehicles especially contribute to air toxins like polycyclic aromatic hydrocarbons (PAH) whose levels have been found to be high in Delhi, said the report.
Quoting the IIT’s recent study on air pollution, the report further stated that high levels of PAH has been found in different locations in Delhi. “Total PAH levels (14 compounds) in winter is very high at 80 ng/m3 (annual standard is 1 ng/m3).
“A 2015 study by the University of Birmingham, which studied road dust on Mathura Road, Delhi, in the summer of June 2013, has found several elements, including copper, zinc, cadmium and lead in high concentrations.
Tailpipe emissions and non-exhaust sources in vehicles like wear and tear of brakes, tyres and other auto parts are one of the major contributors along with industrial and biomass sources. To reduce toxic effect of road dust, further reduction in vehicular emissions and also environmental regulations for car tyres are needed,” said the report.
Emphasising the need to extend odd-even scheme in the city, the report quoted various global examples.
“Several countries have implemented odd and even formula as an emergency action to reduce peak pollution levels. Many of those programmes are more stringent in terms of duration, penalty and minimal exemptions. There are evidences of impact on air quality in those global cities. Several cities have reported a wide range of benefits including reduction in air pollution, reduced congestion, improvement in public transport ridership, etc,” the EPCA report stated.
“Reduction in pollution levels was reported in different cities like in Paris, where this programme was implemented in March 2014 and repeated in March 2015, witnessed 18 per cent reduction in traffic volume and 6 per cent in pollution levels. Beijing, with a longer and more stringent programme, has shown 38 per cent reduction in PM10 level.… The Delhi Government must be permitted to continue with the scheme even if these adverse weather conditions continue,” it added.