‘Pollution Is Back With a Vengeance, Odd-Even Is Need of the Hour’

The Quint catches up with CSE’s Anumita Roy Chowdhury to know if odd-even is indeed the need of the hour in Delhi.

AAP government has got into referendum mode and have sought public opinion before the launch of second phase of the odd even plan. The Quint spoke to the CSE’s (Centre for Science and Environment), Anumita Roy Chowdhury on the gains and pitfalls of Delhi’s anti-pollution policy measure.

Question: The Delhi government claims that the pollution levels are down by approximately 20-25% due to the 15-day trial of odd-even plan. Does the credit really go to the restriction on vehicles or is there some other reason behind it?

Anumita Roy Chowdhury: We have not analysed the government data from 200 locations in Delhi during the ‘odd and even’ week. But our analysis of the real time data from the regular regulatory monitoring of the Delhi Pollution Control Committee has shown that odd-even scheme has resulted in the lowest pollution peak compared to the previous high smog episodes this winter.

Despite the hostile weather conditions — no wind, temperature dip and western disturbance, the peak pollution during odd and even scheme has been much lower. Reduced traffic volume arrested the peaking of pollution.

During odd-even programme day-hours even with lower wind speed have shown faster drop in pollution. Satellite imagery shows ‘lightening’ of pollution over Delhi as compared to NCR during the odd-even fortnight.

Studies show that Delhi pollution level was less than that in neighbouring regions during the odd-even fortnight. But in areas bordering the capital and the surrounding NCR there was no effect, — that saw 35% worsening. Another assessment by the University of Chicago and the University of Harvard has found that the odd-even programme reduced particulate air pollution concentrations by 10-13 per cent during that period.

Question: Should the odd-even plan continue given the fact that citizens in general have given the move a thumbs-up, and two-wheelers be included in that since they far outnumber the four-wheelers plying across Delhi?

Anumita Roy Chowdhury: The effectiveness of the impact will certainly depend on the scope and stringency of the programme. The next round of the emergency action must reduce the number of exemptions and include two-wheelers and women within its ambit.

This will also require immediate roll-out of plan to augment public transport services. In other countries duration of the programme is adjusted according to the severity and persistence of the pollution problem.

Short term program like the one in Paris has seen 18 % reduction in traffic volume and 6% reduction in pollution levels. But Beijing that has a longer and a more stringent programme has shown 38% reduction in PM10.

Question: According to SAFAR, the readings of PM2.5 have continued to remain in the “Very Poor” category with spikes touching the “Severe” category between January 1-15. On the other hand we have Delhi government relying on portable machines being sent to 200 stations and readings being compared to last year, but with no base data available, is it too soon to conclude that pollution levels in Delhi are down within a fortnight?

Anumita Roy Chowdhury: It is also evident that air pollution is back with a vengeance immediately after the scheme got over. The first three working days after the completion of the implementation of the odd-even formula have seen rapid worsening of air – more than 57% jump in PM2.5 levels on first working day, and have stayed elevated at the severe levels.

But it is also important to understand the range of co-benefit that city got during the odd-event fortnight. There was increased public transport ridership. The road rationing allowed all forms of transport to become more efficient, traverse more kilometres and carry more people.

Metro ridership also increased. Bus passengers increased by 8%. The DTC bus fleet utilisation improved from 84% on normal days to 95% during the period when the odd-even policy was implemented.

There was a dip in sale of petrol and diesel which in turn will result in lower pollution. The overall petrol and diesel sales have dropped by 4.7% and 7.8% respectively, from December 2015 to January 2016.

Anumita Roy Chowdhury, Executive Director (Research and Advocacy), Center for Science and Environment

The data available from the ‘Traffic Survey and Travel Attributes Study’ by the School of Planning and Architecture shows that the average journey speed was as high as 50 kmph during odd-even period as against 20-25 kmph speed on regular days.

We have compared the live traffic updates from Google for January 15, 2016 (during odd-even) and for January 19, 2016 (after odd-even scheme was over). Congestion in most roads increased after the odd-even scheme was over.

Question: Nearly two months after its submission, the Delhi government has not put the findings of the IIT Kanpur report in the public domain. News reports indicate that it is in fact dust that contributes more to air pollution than vehicular emissions. Should the government share the findings, would the CSE be able to share some findings of the ‘Source Apportionment Study’?

Anumita Roy Chowdhury: We would certainly urge the government to finalise the report quickly and put it out in the public domain. The data available from the draft report shows clearly that vehicles are the second largest contributor to pollution – both particulate matter and nitrogen oxides.

Moreover, this report has for the first time assessed the secondary particulate that contributes as much as 25 per cent of the PM2.5 in Delhi’s air.

This study has also put a spotlight on air toxins like polycyclic aromatic hydrocarbon. One should also bear this in mind that the road dust which is the largest contributor of PM2.5 is also suspended in the air by traffic and are also the carrier of toxic substances from vehicular exhaust.

From public health standpoint our proximity to tailpipes of vehicles that spew the most toxic emissions, is of special concern. While we need to take action on all sources of pollution on an urgent basis and in a time bound manner to achieve clean air and protect public health, vehicles will require special attention.