No quick fix: How Delhi and other cities can bring down air pollution
Recently, there has been a lot of concern and ensuing deliberations on the high levels of ambient air pollution in Delhi and other urban areas of India. This has prompted various authorities to propose some quick-fix solutions.
In Delhi, for example, some of these proposals include permitting cars with odd/even numbers on alternate week days, entry of trucks during the night hours only, pollution cess on diesel-run trucks entering Delhi, discarding vehicles which are more than ten years old, etc. However, while some of these steps may provide a temporary and very limited relief, if any in the short term, they are inadequate and, therefore, may not yield the desired results for a long term permanent solution for air pollution abatement in Delhi, Mumbai and other cities in India due to the following reasons.
The first and foremost requirement to address air pollution at any given location is to correctly identify all major sources contributing to the pollution at that location. This is a complex exercise, which needs to be done regularly and cannot be quick-fixed by temporary measures as above. By focusing on cars and vehicles, authorities seem to have identified these as the major sources of pollution in Delhi. In contrast, several studies on source apportionment conducted over the past 25 years suggest that the major contributors (even upto 40 per cent) to pollution of particulate matter (PM) are unknown sources, which may include natural dust and anthropogenic emissions from some fugitive sources.
Air pollution is a transboundary issue and it cannot be contained within the boundaries of a city, state, or even nation. Being site-specific, the severity of air pollution at any location depends not only on sources around the location but also on the atmospheric conditions, viz., wind velocity and direction; temperature and pressure. In Delhi, the high concentration of pollutants, most of the time, are thus, associated with the West and South-West to North-West directional winds. Owing to its geographical location, the city of Delhi has mostly remained plagued with air pollution issues as it is prone to poor air quality due to emissions from all directions, including natural dust and man-made pollution from other states. These are the main reasons that the PM pollution in Delhi is often observed to be 50 to 100 per cent higher than Mumbai and other metros.
There are extensive agricultural activities, both within Delhi and its surrounding states, which contribute to air pollution through burning of agricultural wastes in the fields. Needless to mention, a large number of families, above 35 per cent in urban areas and as high as 75 per cent in rural areas, still use polluting fuels, such as wood, coal, cow dung and agro-waste, for their household chores. In addition, indiscriminate open burning of anything, including waste on dump sites, is rampant in and around the city. Further, pollution from micro scale plants and cottage industries often remains unidentified. All these sources are associated with high emissions of PM and, hence, need to be accounted for in terms of their share in air pollution.
Since some natural emissions may be masking the effect of anthropogenic emissions in Delhi, it is essential to investigate the net effect of various man-made activities. Further, it is not only necessary to segregate natural and anthropogenic pollution, but also to apportion the pollution among various man-made activities and identify the major and minor sources amongst them.
It is to be noted that the above arguments in no way justify that vehicles are not a major source of air pollution. They are certainly a major source in all urban areas, but their contribution to PM pollution, based on which the redressal decisions are proposed in Delhi, may or may not be so significant. Particulate pollution is site specific, which has also been established earlier by many studies conducted for Delhi and other cities. Thus, contribution of vehicular emissions to PM pollution may be different at various locations within the same city. Even among all vehicles, which type of vehicle is the major polluter, needs clarity. Hence, in the absence of research based scientific investigations that clearly link vehicular emissions to PM pollution, targeting only cars and trucks is not the right strategy. An undue focus on these vehicles, if they are not major contributors to PM pollution, may not lead to significant reduction in air pollution levels. On the contrary, it may result in waste of financial and other resources.
Also, based on the past experience of similar interventions to control air pollution, viz., replacing diesel with CNG in vehicles, introduction of PUC, introduction of various "Bharat Stage Standards," etc., there is a possibility that the above measures, including "odd/even car policy in Delhi," may not be so effective; instead it may only cause undue inconvenience to people.
The decision of using economic instruments such as imposing an "Anti-pollution Cess" on trucks entering Delhi may not be very appropriate, if not enforced and monitored systematically. The polluting trucks can enter the city by paying the cess, and thus, will still contribute towards further deterioration of the air quality. There is also the possibility that a truck loaded with some polluting material, e.g., loose building material, may pass under disguise of carrying essential commodities, with or without knowledge of enforcing authorities.
Further, even if we are able to restrict all trucks on the periphery of Delhi, their emissions, depending upon the wind direction, would still contribute to air pollution in the city. Similarly, "Night-entry plan" for trucks and other commercial vehicles is highly undesirable as it may create dangerous levels of photo-chemical smog in the mornings due to large emissions during night and photo-chemical reactions coupled with temperature inversion in the morning hours.
Further, without an effective monitoring mechanism, the enforcement of some of these measures will be an uphill task. For example, how would we enforce the norm "Fine of Rs 5000 for open burning?" If there are not enough enforcement measures, people may bypass the law until they are caught red handed. Even if they are caught burning the waste, they may prefer to a pay a lesser amount dubiously to the enforcement agencies thereby encouraging corruption and augmenting levels of air pollution.
Socio-economic conditions of most of the car/ vehicle owners in India will make it difficult to implement norms such as "discarding a 10 year old car/ vehicle" until there are significant incentives provided by the government or auto manufacturers to the users. Also, it is not the age of car/ vehicle but quantum of emissions from it, which is responsible for air pollution and it depends on the car's/ vehicle's mileage, frequency of its use and its maintenance. With "age of the vehicle rule for all," we may unknowingly penalise those consumers, who either due to economic or any other reason, use their cars/ vehicles sparingly. For example, most of those living within the residential campus of an educational, IT or similar organisations either due to their environmental awareness or due to proximity to their workplace often use their vehicles for only few hundred kms per year. Expecting a 10 year old diesel car to be scrapped, inspite of having a total mileage of say, around 5000 kms is unreasonable. Further, such cars from Delhi and other cities, along with their presumed polluting characteristics, may shift to smaller towns and, thus, this rule will only displace pollution and increase an overall pollution at national level.
A comparison of car ownership indicates that cities in the developed world have much higher car ownership than those in developing countries. For example, the number of cars per 100 persons is 56 in Melbourne, 30 in London, 21 in New York, 18 in Tokyo, while, in Delhi it is only 5 to 6 and in Mumbai 2 to 3 cars per 100 persons. In fact, Mumbai is one of the cities in India where pollution levels are above their prescribed limits on 35-40 per cent days of the year.
On the other hand, in some much smaller towns such as Jaipur and Lucknow, having much lower number of cars than metros, pollution levels are above these limits on more than 90 per cent of days of the year. All these figures indicate that number of cars and vehicles are not the only indicators of high levels of air pollution in Delhi, Mumbai and other urban areas. Further, by restricting number of cars on the road but, at the same time, introducing more number of auto-rickshaws, taxis, etc., will neutralise any reduction in air pollution levels, which, if at all, may be due to limiting the number of cars on the roads. Travelling by autorickshaws and two wheelers may also have an adverse effect on health of people as it increases our exposure to air pollution upto 2 to 3 times as compared to travelling in a closed transport vehicle like bus or car.
Hence, most of the measures suggested by the authorities are only short term and inadequate and these may not address the air pollution issues in Delhi, Mumbai or any other Indian city effectively and on a long term basis. So what is the solution then? In this regard, we should not follow other countries on a general basis and suggest impractical measures. We may consider the following for an India specific solution.
As mentioned earlier and, it is also evident from variable levels of air pollution reported at various monitoring locations of CPCB in Delhi, air pollution is a site-specific phenomenon.
Since pollution sources are site- specific, the measures to tackle pollution at any location should also be site-specific. Hence, "one size fits all" formula may be ineffective for all cities or even for all areas within a particular city. The estimation of source contributions to air pollution, using emission rates from various sources, will neglect emissions from natural and unknown sources. Thus, ambient air pollution levels at a location, which are the actual levels to which people are exposed, may not be the same as the sum of emissions from all sources estimated using this method. Therefore, contributions to pollution from various sources at a specific location needs to be estimated through source apportionment (SA) studies, which give a better picture of major and minor sources of pollution at a particular location. These studies estimate the contribution of all major sources by using actual air pollution data monitored at that location. In the past 25-30 years, several SA exercises have been conducted for Indian cities including Delhi and Mumbai. Unfortunately, instead of being a regular exercise and a decision making tool they have been conducted either for academic purposes or sort of a symbolic action taken up by the concerned authorities in collaboration with academicians and researchers.
Thus, it may be necessary to conduct the SA studies frequently to see the changes in pollution at various locations vis-à-vis the share of contributing sources at those locations. The results of these SA studies should be used to first segregate the share of pollution from natural and anthropogenic sources to know the net contribution from all major man-made sources. Further, it is possible to apportion the pollution from all man-made sources and ascertain the major and minor anthropogenic sources. Once, we are able to identify the share of pollution from major man-made sources, we can then focus and implement appropriate remedial measures, accordingly.
A large portion of the population in Delhi and other Indian cities still do not have access to electricity and other forms of clean energy for domestic chores. Such households must be provided the same in order to avoid use of traditional biomass and other polluting fuels. The central government schemes of extending the LPG facility and provision of electricity to all families need to be accelerated as such steps will make a significant reduction in air pollution due to domestic biomass burning. Sustainable energy options, viz., biogas, waste-to-energy, etc., are not only less polluting, but will also go a long way in an effective waste management.
There is an urgent need to increase the use of vehicles powered by various forms of renewable energy, such as, batteries, solar power and those using less polluting liquid fuels. About ten years ago, there was an impetus for the promotion and use of biofuels such as biodiesel and ethanol, which needs to be accelerated once again. Research in clean technology and fuels should be enhanced so that some indigenous technology can be developed that may help reduce the levels of air pollution. Until we are self-sufficient in developing our own technologies, we could even import such technologies or vehicles from countries that have successfully used them to reduce their local air pollution. Simultaneously, we may also think of promoting the use of bicycles and cycle-rickshaws and construct safe routes for them along the roads and footpaths.
Low levels of awareness and education, lack of civic sense, resistance to change and "not in my backyard attitude" of people are the most paralyzing issues for deteriorating condition of environment in the country. People often complain about the inappropriate and inadequate government measures but hardly change their own life style or contribute to improving the conditions in their own neighbourhood. For example, throwing garbage in the open and its indiscriminate burning cannot be addressed by mere governmental measures such as fines and penalties; it also requires effective cooperation and willingness of the people to bring about the change. Recently, the media has played a major role in highlighting the benefits of "Swachh Bharat Abhiyaan." Thus, education and awareness of masses needs to be increased to enlighten people about the detrimental effects of polluting activities on their health and society.
Prior to adopting some short term remedial measures, such as use of odd/ even cars, car-pooling and restricting number of car registrations, etc., authorities may ascertain the quantum of positive effect of their actions. For a quick assessment, they may consider implementing a "no car day" or "even a no vehicle day" in Delhi. To minimise the inconvenience caused to people, such days may be observed either on a weekend or on a public holiday and may allow emergency and public transport vehicles only. Measuring air pollution on such days and comparing it with that on other days (when all vehicles are on roads), will give a quick, clear and practical idea about the actual reduction in pollution levels, if any, by removing cars/vehicles from roads.
Local air pollution has a direct link with global air pollution, climate change and global warming. If we are able to reduce local air pollution, we will not only reduce its adverse impact on our health and property, but will also contribute to reduction in greenhouse gases resulting in enhanced global warming. In the recently concluded COP-21 conference in Paris, India has already committed to restricting its carbon emissions and abatement of local air pollution will have a significant effect in meeting this commitment.
To conclude, while the measures suggested by various authorities in Delhi may have some marginal and short term effect on air pollution control in the city; for a long term and permanent solution to tackle in Delhi, Mumbai and other urban areas of India, it is necessary to adopt an effective strategy.
As mentioned above, it is essential to identify and segregate the quantum of natural and anthropogenic (man-made) pollution. Also, the quantitative contribution from various man-made sources should be ascertained and, accordingly, the remedial measures should focus on the major sources of air pollution. To repeat, the menace of air pollution cannot be tackled by regulations alone and their strict implementation and enforcement by authorities and cooperation of masses are crucial. This will necessitate involvement of all stakeholders in pollution reduction measures including public authorities, private sector, NGOs and common people.
Note: This article is based on the extensive field studies conducted by authors in Delhi and Mumbai and expresses their personal views. Prof. Vinod Kumar of IGIDR, a Premier Research Institute of the RBI and a Deemed University in Mumbai, is an expert on Environment and Air Pollution. Dr. Sangeeta is an international consultant on Corporate Social and Environment Responsibility (CSER).