CSE Condemns Misrepresentation of Findings of Recent CSIR Study on Diesel and CNG Buses

BeyondHeadlines News Desk

New Delhi : Centre for Science and Environment (CSE) condemns the recent attempt to misrepresent the findings of the new study that has been jointly carried out by the CSIR, IIP-Dehradun and University of Alberta. The statements from CSIR have claimed, without presenting the full study and the facts in the public domain, that CNG buses emit more ultrafine particles than diesel buses and are a health hazard. When CSE obtained the draft findings from CSIR it was stunned to see a very different message from the study. Their own findings have shown that the conventional CNG buses in India have already achieved emissions levels for all pollutants including ultrafine particle number very close or better than Euro VI emissions standards that are yet to be implemented. Diesel buses are far behind. The ultrafine emissions from Indian CNG buses are higher only from the Canadian diesel bus with advanced particulate traps meeting one of the global best standards.
This motivated campaign against CNG buses in India, and defiance of what science is saying, will harm not only the CNG bus programme that has given enormous public health benefits but will also jeopardise the policy decision to leapfrog emissions standards roadmap to Euro VI by 2020 to cut dangerous diesel emissions. The government of India is dragging its feet in the face of strong opposition from the diesel industry. Diesel technology and fuels need the most drastic transformation in Indian transport sector today to protect public health.
CSIR has shared the draft findings with CSE. The highlights of the review of the findings are as follows:
This study, done jointly by CSIR-IIP-University of Alberta, has carried out real world emissions tests on 2 Indian CNG buses (model year is not mentioned) and two diesel buses one of Canadian make meeting current US Tier II standards fitted with advanced particulate trap; and one Indian diesel bus without diesel particulate trap. It may be noted that US Tier II norms are tighter than the Euro VI norms. The measurements were carried out while accelerating and cruising the vehicles.
  • Ultrafine particle numbers from Indian diesel bus are at dangerous levels: Ultrafine particle emissions from Indian diesel bus without particulate traps emit 600 to 2000 times more than the Indian CNG bus. CSIR should have put out a red flag immediately to highlight this concern and urged the government to leapfrog to Euro VI emissions standards when much tighter particle mass standards and particle number standards become applicable. Ultrafines are of 0.1 micrometer size and 25 times smaller than PM2.5 go directly to the blood stream and in conjunction with the finer particles of PM2.5 and PM1 they cause irreparable damage to health. PM2.5 is already the 5th largest killer in India.
  • Indian CNG buses are already close or better than the Euro VI emissions standards: Even more dramatic finding is that the conventional Indian CNG buses have ultrafine particulate number emissions close to the Euro VI standards for particulate number. While the limit value for particle count under Euro VI emissions standards is 600 billion particles per kwhr, the actual observed level in one CNG bus is 278 billion particles per kwhr and in the second 950 billion per kwhr. This shows the current CNG bus fleet gives Indian cities a much better opportunity to leapfrog to Euro VI emissions standards. In contrast, the current Indian diesel bus was found emitting 1000 times more ultrafine particle numbers compared to Euro VI limit on transient cycle.
  • CNG buses have performed much better on all other pollutants than all diesel buses: The reportage on this study is silent on the performance of CNG bus on all other parameters including carbon monoxide (CO), non-methane hydrocarbon (NMHC) and nitrogen oxide (NOx) that have also been tested as part of this study. These results show that both CO and NMHC emissions from the current CNG buses are close to the limit values of Euro VI norms. CO, NMHC and NOx emissions from Indian CNG bus is also much better than the Canadian diesel bus meeting tighter emissions standards. The NOX emissions are actually within the limit values for Euro VI norms on transient cycle. But the actual CO emissions from Indian diesel bus without trap are 19 times higher, NMHC emissions are 47 times higher, and NOx emissions are 17 times higher than the limit value for Euro VI emissions standards.
  • Conventional Indian CNG buses have been compared with Canadian diesel bus with advanced particulate traps and NOx controls meeting one the best global standards. But there is no data on how CNG buses in Canada meeting the same tighter standards perform: Only when Indian conventional CNG bus was compared with the Canadian diesel bus with particulate traps and advanced NOx control meeting US Tier 2 standard, tighter than even the Euro VI standards, the study found levels of ultrafine to be 12 to 40 times higher. But it has not been mentioned what genre of Indian CNG bus has been compared. But more important, the same study shows that the Indian diesel bus without particulate trap emits 28,000 times higher ultrafines compared to Canadian bus with particulate traps – much worse than Indian CNG bus.
The study has only reconfirmed how CNG bus fleet is giving the overall environmental benefits compared to CNG buses even today.
Do not detract policy makers from the health risk from current quality of diesel in India: CSIR has omitted to mention the serious health risk associated with diesel emissions. It is now well known that the WHO has concluded that diesel exhaust is a human carcinogen and is in the same class as tobacco for its strong link with lung cancer. It is also widely known that diesel particulate mass and the number of nano particles are very high and contribute to the most hazardous pollutant PM2.5. This is part of PM2.5 which currently is the fifth largest killer in India. Due to engineering challenges our norms allow diesel to emit three times more NOx and seven times more particulate matter than petrol. The norms for petrol and CNG are same as they have similar engine types. Dieselisation contributes to both PM2.5 and ozone in our cities. Current evidence indicates CNG has much lower PM and toxins. It is evident from the assessment of global agencies including the USEPA, California Air Resources Board and European regulatory agency that the toxicological risk associated with CNG pales in comparison with the total weight of evidence for the association between exposure to particulate matter and adverse health.
Do not confuse. Give clear roadmap
The new study has enough evidences to suggest why India needs to leapfrog to Euro VI emissions standards and particle count standards to clean up diesel emissions quickly and also to further leverage the clean potential of CNG to meet the clean air benchmark.
CNG based public transport system has already given enormous opportunity to cities to have a win-win strategy of clean fuel based public transport. But there are many cities that do not have CNG and will continue to use diesel. Moreover, all trucks and buses across the country will need clean diesel. It is therefore important that a quick transition is made to clean fuel and vehicle technology benchmarked to Euro VI standards
  • Based on its own finding CSIR should advise government to leapfrog to Euro VI emissions standards including the standards for particle count and not undercut the CNG programme.
  • Announce emissions standards roadmap immediately to ensure that the country has Euro IV emissions standards nation-wide this year and leapfrog to Euro VI emissions standards by 2020
  • Government of India should at the same time strengthen the roadmap for CNG bus programme in cities that have access to CNG to maximize environmental and public health benefits.

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