Steering the way
The computer-generated Anil Agarwal Clean Air Model, developed by CSE, assesses what it takes to clean up Delhi's air. Some astounding results have come out of its first application. Had the …
New Delhi, 15 November
In 1998, Delhi witnessed one of the worst winters of the decade. For much of the season, the city was enveloped by a deadly smog. Respiratory illnesses were rising and there was an alarming increase in hospital admissions. As officials were caught up in the all-familiar inertia, the Supreme Court stepped in. What followed was a series of rulings that have laid the foundation for a roadmap to clean up Delhi's air. People already feel the difference. The air is much cleaner now than it was in 1998. But most people don't know exactly by how much emissions have come down.
"The public must come to grips with precise information rather than some generalities because they don't lend themselves to any action. People's state of air pollution report will help to spread information about the precise nature of the problem and solution. No one can be perfect but it helps to be as precise as you can," said Anil Agarwal, former chairperson of Centre for Science and Environment (CSE). This was his clean air campaign message to the people in January 2000. This was also the beginning of a very rigorous number crunching process at CSE - in technical parlance a computer model to estimate the trends in vehicular emissions load and impact of different policy measures. The objective was to make people aware and understand what has been achieved due to the Supreme Court's intervention and how we must move ahead.
The model captures Anil's vision and his anguish. "None of us as of yet have enough information to know how to clean up Delhi's air with precision. But in two years we have done our best to identify key actions with as much precision as we can. So precision will come with time. It evolves. But make every effort not to advocate sloppy decisions." The clean air model is a people's model and a guard against sloppy decisions. People can use this to know precisely the impact of policies on air quality now and in the future. It can help to formulate policies, assess their impact and then push the government to act.
The CSE's Clean Air Model
So far the transition has come about only due to the Supreme Court's initiative, which forwarded Euro II emissions standards for new vehicles, lowered sulphur content in diesel and petrol to 500 ppm, mandated clean fuels like compressed natural gas (CNG) for public transport, and phased-out 15-year-old commercial vehicles. In addition, it ruled for better inspection and maintenance programme for in-use vehicles, strengthening of air quality monitoring and checking adulteration. These measures have made a visible impact and are setting the agenda for other cities as well. But much more needs to be done.
But these gains can be frittered away so easily because of the lackadaisical attitude of the government. For all its efforts the court actions have stabilised the runaway pollution - an achievement in a city that recorded particulate levels reaching as high as eight to nine times the standards. But it is still way above the permissible limit. Clearly, it is time to take a hard look at the decade-old unresolved question of what needs to be done to clean up the vehicular fleet.
The conservative roadmap underestimates the gravity of health effects from vehicular exhaust - nothing new for officials. But this time the committee has worked hard to blow out of proportion the uncertainties in health studies. The policy admits that a number of disease conditions are attributed to air pollution but says that "even those studies that have been conducted in the advanced countries, are not able to pinpoint disease risk to pollutants from vehicular emissions."
The report admits that air pollution is bad, but is at pains to stress that vehicular pollution per se is not that bad. All along it understates health effects of particulate emissions, particularly from vehicular sources. It keeps emphasising "very large uncertainties" in studies on impacts of air pollution. For example, the report says, "much less certain is the extent to which primary PM10 from road transport exhaust is responsible for the health effects of PM10." It is shocking how the expert report underplays the effect of PM10 on human health: Noses trap about 90 per cent of the inhaled pm, letting only the smallest ones that "tend to be deposited in tiny air sacs deep down" and there can be then "some health problems".
Studies are further selectively cited to state that even PM2.5 poses limited risk, if any, to normal healthy subjects, and those predisposed to other respiratory diseases may be at risk of developing adverse responses. It is amazing that the most recent and most extensive study done so far on pm exposure, published in the Journal of American Medical Association based on research spanning over 16 years, 500,000 people, and 116 us cities has gone unnoticed. This shows how a mere increase of 10 microgramme per cubic metre in fine particles can increase the risk of lung cancer by eight per cent and cardiopulmonary disease by six per cent (see 'No escape', Down To Earth, Vol 10, No 22).
As far as the problem of diesel particulates is concerned, the committee admits there are studies, but claims that these are firm only on occupational exposures. "The evidence is weak" both on cancer and non-cancer effects of diesel exhaust though there can be adverse effects due to long-term exposure. It is strange that while in the case of outdoor air pollution and particularly, pm and diesel exhaust, the uncertainty factor, - that normally any scientific medical research would state, assumes such obsessively high significance, health impact assessment of indoor air pollution is presented without any question. It states with certainty that health effects of indoor air pollution - such as burning wood in chulhas - would be 100 times higher compared to outdoor air pollution.
This is clearly a case of missing the woods for the trees. The committee should have gone a step further to look at how regulatory agencies around the world use health information to chart out preventive and aggressive measures even in the face of extreme uncertainties. The committee needs to be told that absence of evidence is not the same as evidence of absence. It must learn from the experience of us Environment Protection Agency (USEPA): The USEPA undertook the Health Assessment Document for Diesel Engine Exhaust after the California Air Resources Board branded diesel particulates as 'toxic air contaminant' in 1998 after a 10-year review of diesel exhaust. This assessment guided the USEPA to set the most stringent emission standards for heavy-duty vehicles for 2007, that are expected to cut emissions by as much as 95 per cent. The USEPA also acknowledges uncertainties in current knowledge but chooses to state that "it is still reasonable to presume that the hazard extends to environmental exposure levels."
Stringent standards for future vehicles would depend on how the share of vehicles' contribution to the total pollution load is understood. If its share and its health impacts are considered insignificant, then it is an immediate recipe for a weak roadmap. And that is what has precisely happened.
What has come in handy in justifying a weak roadmap is a study done by Central Road Research Institute (CRRI), New Delhi, to assess the vehicle-kilometre travelled and pollution load contribution in different cities including Delhi.
The way CRRI has profiled Delhi traffic will make even the us and Europe jealous. The average age of cars is just 3.5 to 6.7. Higher number of ageing fleet is a myth after all. It is amazing that even after considering such a young fleet and 55 per cent of the registered data (a likely possibility), Delhi still tops the chart with pollution load from vehicles as the highest compared to other cities. So it still qualifies for advance action but not strong enough action.
The committee's contentment comes from the estimation that "if the business as usual scenario were allowed to continue till 2010, the pollution load from traffic would remain virtually the same as in the base year (2002). This is in spite of the estimated increase of about 50 per cent in traffic loads." This is so because newer technology will replace older vehicles in due course. So it implies if we do anything better, however little that may be, we only stand to gain. No need for a bolder roadmap!
What stumps is the way the committee decided to settle down for a weaker Euro IIi in 2005 instead of Euro iv standards. They argue that while their proposed roadmap will cut particulate matter by 40 per cent, early introduction of Euro iv in 2005 can further reduce pm load only by 2.2 per cent in 2010 in Delhi. So why make a huge investment for such a small incremental gain? The basis of this calculation is not explained. But experts should at least know that it is well-known the world over that any improvement from unregulated or poorly regulated scenario shows much larger reduction in percentage terms that make subsequent improvements seem marginal. But incremental gains with greater advancements are more relevant from the standpoint of meeting air quality targets.
The committee admits that the various policy measures implemented so far (courtesy the Supreme Court) have made considerable reduction possible in Delhi. But it warns not to attribute it largely to compressed natural gas (CNG). Improvement in fuel quality and vehicle technology have reduced pm load by more than 88 per cent. CNG's contribution is a mere 11 per cent. Interestingly, emissions factors for CNG buses considered are for converted buses even though CNG scenario assumes equal division between new and converted buses. That selection of emissions factors is critical is even admitted, "variation of 10-20 per cent in emissions factors are likely to result in 15-25 per cent variation in the estimation of pm load." Again, deterioration factors considered for diesel vehicles show that hydrocarbon and nitrogen oxides don't deteriorate. The result is an underestimation of diesel emissions and overestimation of CNG emissions. Not surprisingly, the report insists, "The 'popular perception' that air quality in Delhi has improved only due to CNG is not borne out by this technical study."
The committee, in fact, asks to step back from what the court is trying to achieve. It recommends that all inter-state buses and trucks originating or culminating in Delhi should conform to India 2000 by April 2004 and Bharat stage II norms by April 2008. It ignores the Supreme Court's contention in July this year that no goods vehicle will be allowed to enter the city unless it meets Bharat stage II norms. Besides, Bharat stage II norms is already in force for all vehicles in Delhi.
Naturally, the committee does not consider incoming goods vehicles to be a problem as CRRI survey shows it is such a young and clean breed trucks - mean age 5.4- 5.5 years. About 90 per cent of goods vehicles are within nine years of age. An analysis by CSE recently of pollution under control (puc) data collected from 13 centres spread across Delhi for vehicles in different categories showed that around 32 per cent of goods vehicles tested were more than nine years old.
Clever approach this. Understate the worrying concerns and taper down the roadmap to suit what the industry and the government agree to achieve. The policy does not acknowledge the need to drive technology fast to address public health concerns. The Auto Fuel Policy is a product of bad science and atrocious politics. A deadly combination for Delhi's residents.
Model concept: Anil Agarwal
Developed by Sunita Narain, Anumita Roychowdhury and Chandrachur Ghose. Advisor: H B Mathur
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.