CSE says ambiguous Delhi IIT studies on vehicular air pollution being used selectively by ministry of road transport and highways

 Slams the ministry for trying to confuse and slow down policy action on vehicular pollution and block decisions on old diesel vehicles

  • CSE has carried out rapid review of available studies in Delhi that make the case for urgent and priority measures to cut people’s exposure to toxic risk from vehicular emissions even while taking action on other pollution sources 

  • There is enough evidence to show that older vehicles emit more particulate and toxic gases than the new generation vehicles and will require a plan for quicker phase out

  • In a bid to protect old cars the science of exposure risk to deadly vehicular pollution has been played down in the IITD-TRIPP studies and the MORTH affidavit. This has serious risk of slowing down action not only on older vehicles but also on new vehicles. 

  • There is enough evidence in Delhi to prove significant contribution of vehicles to multi-pollutant crisis and health risk and justifies the strong action demanded by NGT on vehicular pollution and on old vehicles.


New Delhi, May 25, 2015: Centre for Science and Environment (CSE) is shocked at the selective use of limited studies of Transportation Research and Injury Prevention Programme (TRIPP) of the Indian Institute of Technology-Delhi (IIT) to argue that vehicles are small contributors to ambient PM2.5 levels in Delhi and that banning older diesel vehicles will not help. This has been used in the official affidavit of the Ministry of Road Transport and Highways (MORTH) to the National Green Tribunal (NGT) to play down the problem of vehicular pollution and block the ban on old diesel vehicles. 

Says Anumita Roychowdhury, executive director, CSE: “This confuses policy action needed to reduce exposure to toxic vehicular pollution at a time when a bouquet of measures is needed to effectively reduce the health risk in Delhi.” 

This has come in the wake of the NGT order that had directed all diesel vehicles (heavy or light) which are more than 10 years old, not to be permitted on the roads of NCR, Delhi. All the authorities in the state of Haryana, U.P. and NCT, Delhi would not register any diesel vehicle which is more than 10 years old. 

In response to this order, the Ministry has relied on the Delhi-IIT studies to counter NGT directives. It has ignored a range of other evidences in Delhi demanding urgent, stringent and more complete action on vehicular pollution. 

While resorting to number crunching to prove vehicles do not contribute much to ambient PM2.5 levels, the IIT-study and the affidavits are silent on health risks from direct exposure to vehicular fume especially diesel fume which is of bigger concern. While the NGT order covers all old diesel vehicles in both private and commercial segments across NCR, this study focuses only on old cars in Delhi to stop the NGT ban. It has not made any alternative suggestions on how to discourage, restrict and phase out old diesel vehicles that is emerging as a practice globally. 

Says Roychowdhury: “In the name of comprehensive action on all sources within and from outside Delhi it is not correct to dilute action on individual sources. All sources will require action but priority action will have to be directed at reducing the direct exposure of people to toxic fumes close to their breathing zone. CSE demands robust scientific guidance to frame policy for cutting health risks from vehicles including old diesel vehicles as part of the clean air action plan in Delhi and NCR.”

CSE has carried out an assessment of the available evidences in Delhi that highlight significant contribution of vehicular pollution as well as the special risk associated with older vehicles. The highlights are as follow:

i. IITD/TRIPP study and affidavit of MORTH underplays the risk from older cars and is silent on diesel commercial vehicles in the NCR: The IIT-Delhi study states that 11-15 years old diesel car numbers are very small – only 6% of the fleet and contributes 1% of PM2.5 pollution. 

This is a misleading way of presenting evidence and giving policy advice. The emission load from diesel vehicles that are 11 to 15 year old and meet older emissions standards emit a lot more on a per vehicle basis than those that are between 1 to 10 year old. This is evident from the emissions factors that the Automotive Research Association of India had developed for different generation of vehicle technologies meeting different emissions standards. Compared to a BS IV car a 15 year old diesel car emits 7.6 times higher particulate matter and 3.4 times higher NOx. Thus, emissions from one old diesel car are equal to four to seven new cars. A 10 year old diesel car emits 2.4 times higher PM. Air toxics emissions are high from older vehicles. The difference emissions of different genre of commercial vehicles are also substantial. Diesel car emissions are also much higher compared to petrol cars. From health stand point these emissions close to where people are. Removing old diesel vehicles will reduce substantial direct exposure on roads. This benefit can be maximized and be substantially much higher if the old diesel trucks are also removed and bypassed.  

ii. IITD/TRIPP study and MORTH affidavit says instead of banning old diesel cars enforce PUC tests without highlighting the laxity of PUC norms that cannot fail most vehicles: 

It is unacceptable and misleading to claim that the current PUC norms and practice for pre-Bharat Stage IV diesel vehicles (65 HSU smoke density norm) are adequate to address emissions from the older fleet. These norms are extremely lax for Bharat Stage I and Bharat Stage II diesel vehicles that are targeted to be banned. Globally the smoke density norms for diesel vehicles are much tighter. In Asia, countries including Thailand, Hong Kong, Indonesia, and Malaysia have enforced 50 HSU smoke norms for older vehicles. Pakistan and Singapore have enforced as low as 40-HSU norm. Lax norms and poor test procedures make diesel PUC a sham and of no relevance. CSE review of the PUC norms has shown that these can barely fail maximum of 6% vehicles. It can be much less than this. It is therefore misleading to think that the current PUC programme can be a panacea for old diesel vehicles. 

iii. IITD/TRIPP study and MORTH affidavit claim vehicles are a small contributor to PM2.5 pollution – 17% to 20%. Ignores multi-pollutant crisis and cancer effects of diesel fume:   

It is inexplicable why Ministry of Road Transport and Highways has considered the estimates of only one study on the estimates of vehicles contribution to PM2.5. The IITD study fails to highlight the health risk from the direct exposure to vehicular fume that is of serious concern globally. Vehicular emissions take place within our breathing zone. Studies by Health Effect Institute for Delhi have shown that the influence of vehicular pollution is maximum upto 500 meters from road side and more than half of Delhi’s population live within this breathing zone. Also studies and pollution measurements carried out by CSE and University of California, Berkeley have shown very high exposure on and along road sides in Delhi. IIT-D-TRIPP has not considered these exposure impacts that are the key concern from health stand point and should guide policy action. It has not guided the government and NGT about the toxic risk and the fact that WHO and IARC have classified diesel exhaust as Class 1 carcinogen for its strong link with lung cancer. 

iv. There are several other studies from other notable agencies that show significant contribution of vehicles to air pollution and toxic risk. Some of these are as follow: 

Indian Institute of Tropical Meteorology study for Delhi-NCR finds transport sector contribution to PM2.5 to be as high as 45% followed by residential sector at 27%, industries at 24% and power sector at 4%. (2011)

JNU study finds vehicles contribute 86% of fine particulates (2008): This study finds that if coarse particles are concerned crustal re-suspension is about 68% followed by vehicular pollution at 23%. But in fine particles vehicles contribute 86% and crustal re-suspension at 10% and industrial contribution was 2%. 

A study by UrbanEmissions.info (also co-author of Delhi IIT study in question) highlight multi-pollutant crisis -- vehicles contribute 26% of PM2.5, 28% of CO, and 67% of NOx. 

A study by Centre for Atmospheric Science of IIT Delhi, National University of Colombia, Bogota, Colombia, (2014) have found that total estimated emissions from vehicular exhaust, road dust and power plants contribute nearly 52%, 83%, 74% and 54% of PM10, SO2, NOx and CO emission respectively. Transport sector has been found as the bulk contributor towards CO and NOx emissions. 

The CPCB, DRI, Chinese Academy of Sciences study of 2014 states that since the adverse effects of PM10 depend on its chemical composition, it is important to control emissions of toxic species (2014): It indicates that diesel-fueled vehicles contribute nearly all of the vehicular elemental carbon (96%) and most of the PM10 mass (81%), OC (82%), primary sulphates (75%), and Ni (71%). The Heavy-duty diesel vehicles mostly trucks were the largest emitters among on-road vehicles, contributing 47% of organic carbon, 57% of elemental carbon, 56% of primary sulphate particles and 37% of primary nitrate particles, 30% of lead, and 35% of Ni emissions. Light commercial diesel vehicles contributed in the range of 10–30% of vehicular emissions.

Profile of PAHs in the Diesel Vehicle Exhaust in Delhi, (JNU 2005): The concentration of Total PAHs was found to be high in the exhaust of diesel buses and trucks – higher in trucks. High concentration was influenced by age of the vehicles, driving conditions, the fuel quality and the emission standards. These are air toxins and contribute to cancer risk. 

v. IITD-TRIPP study and MORTH affidavit states that there is no significant reduction in PM2.5 levels on Sundays and strike days when vehicular traffic is expected to be less. According to them this proves contribution of vehicular pollution in not significant in Delhi.  

A study by Delhi Technological University and CPCB, published in 2013 on the weekday/weekend differences has analysed a comprehensive database for pollution levels from the year 2006 to 2010 for a main traffic intersection at ITO, Delhi. The pollution levels on weekend i.e. Saturday and Sunday relate to significantly lower concentration of pollutants as compared to that by almost 2 to 6 times. 

CSE has also compared official air quality data for national holidays that show substantial reduction. For instance, on January 26, Republic day of 2013, (when traffic is restricted) PM2.5 levels in RK Puram declined by 1.5 times compared to the previous day and rose on January 27 and to 345 microgramme per cum or 2.25 times by January 28. In Punjabi Bagh PM2.5 levels were 140 microgram/cubic metre on Republic Day that rose to 187 on January 27th and to 216 on January 29th. Similarly, on October 2, 2013 – Gandhi Jayanti day, PM10 level in RK Puram was 108 microgram/cubic metre on 1st October, that dipped to 63 microgram/cubic metre on October 2nd and rose to 151 on October 4th and 251 microgram/cubic metre on October 5th.  

vi. Global best practices

Globally strategies are being adopted to quickly phase out older vehicles to maximize the benefit of pushing the new vehicles to meet Euro V and Euro VI emissions standards. These include ban on old vehicles, colour coding to restrict and phase out old vehicles, high taxes on older vehicles, and stringent in-use emissions inspection and test procedures.

Old vehicle phase-out policy in China/Beijing: It is important to note that the strong measures that have been adopted in Beijing where vehicles contribute 31% of PM2.5. China has framed a comprehensive policy for old vehicles. 

During 2011-14, over 1.4 million vehicles older than 6 years were retired or replaced in Beijing. Introduced environmental label system -- Yellow: Euro 1 gasoline, Euro 3 diesel; Green: Euro 4; Blue Euro 5. This also includes use of electronic tags, and embedded chips in vehicles since 2009 so that information about the vehicle can be stored and remote reading can be taken. Vehicles without labels are illegal on road. Tough penalties are enforced for violation. Traffic restriction of yellow label vehicles began in 2003. It is forbidden to run within the 5th ring road since 2009 and within the 6th ring road from thereafter. There was phase out of 6 million yellow label vehicles in China in 2014. China will eliminate yellow label vehicles in key regions by the end of 2015 and all yellow label vehicles in China by the end of 2017. 

About 20,000~30,000 heavy duty trucks that registered in neighboring provinces run into Beijing and exceed standards be listed in “ smoke blacklist ” and fined by local Environment Protection Bureau. 

For in-use emissions tests Beijing has introduced Lugdown method to test buses and trucks using more than 100 dynamometer testing lines in 43 inspection stations. 

The way forward

It is disturbing to note that instead of conveying the seriousness of health risk from vehicular emissions and helping to frame robust action strategies to reduce exposure to vehicular pollution, science has been used to take a very narrow view of the mitigation strategies to dilute action. 

CSE review of available evidences shows that vehicles contribute significantly to multi-pollutant crisis and health risk and exposure in Delhi and there is sufficient justification in the directives of the NGT for demanding strong action on vehicular pollution and on old diesel vehicles. 

It is important for Delhi to implement a detailed plan for phasing out of old vehicles, more stringent inspection and PUC norms for old vehicles, annual and higher taxes on vehicles, restricting movement/banning of old and polluting vehicles for sustained impacts over time.