Addressing India's Air Quality Challenge: Understanding Air Quality (Part II)

This is the second section of a four-part policy note on Addressing India's Air Quality Challenge: Improving Knowledge, Communications and Institutions which discusses the major gaps in our understanding of creation, measurement and impact of pollution.

Wider Coverage and Cost-effective Data Generation

… the understanding of air quality, its components, the chemical processes and their interaction with climatic and human activity will need to be better understood. 

As India will grapple with endemic pollution across the length and breadth of the country, the understanding of air quality, its components, the chemical processes and their interaction with climatic and human activity will need to be better understood. Improved measurement includes coverage of a larger set of pollutants, availability of data for a full range of pollutants for across the country and for any point in time, universal accessibility and improved analysis of the available data.

Low-Cost Monitoring Equipment

There are 240 cities and towns that have 573 air quality monitoring stations as of July 2019 as per data put out by the Central Pollution Control Board. [1] There are no doubt other monitoring stations as well, for instance, those put up by the Ministry of Earth Sciences, ASAR etc. but they are nowhere close to the number of cities and large villages in India; as of 2011 there were a total of 7,935 cities and towns and 5,97,608 villages of which as many as 782 villages have a population above 20,000.[2] Increasing coverage, therefore, is important so that all locations with significant population are well monitored for a range of pollutants on a real-time basis. It is evident that the expensive nature of conventional pollution monitoring is a constraint, the solution is to enable the use of other cost-effective alternatives. This will ensure a rapid spread of monitoring devices and availability of estimates for the thousands of cities and also the rural heartlands.  

To enable this, India requires (a) building of a robust administrative mechanism where lower-cost instruments are recognized/ licensed and kept well-calibrated and (b) developing robust synthetic methods where RS imagery can be combined with a few ground sensors to generate synthetic estimates. The former requires an entity such as the CPCB to first recognize and then to build a proper mechanism for low-cost instruments to be widely accepted. CPCB could, for instance, develop an innovation window for rapid validation and acceptance of innovation. [3] 

The role of the research community is important in that it feeds regulatory action…. The development of basic principles and best practices for creating synthetic estimates of pollution is one example.

The role of the research community is important in that it feeds regulatory action, as the latter tends to follow scientific/technology developments.  The development of basic principles and best practices for creating synthetic estimates of pollution is one example, where globally accepted standards are emerging following a host of published research. A white paper can be brought out by the CPCB on the same.[4] Traditionally monitoring equipment meets a certain set of highly precise requirements, and consequently is costly both to acquire and maintain. However, new technologies are making available monitoring equipment which may not be as precise but have low acquisition and maintenance costs. Consider two aspects. First, reduced costs sometimes require much more careful calibration and care of the equipment. A mechanism that ensures careful calibration and maintenance of such equipment needs to be put up. Second, globally as well as in India cost-effective high precision instruments are being developed where such calibration is not required. The CPCB would do well to study, analyse and incorporate such instruments.

Synthetic Estimates

In the same context, new and disruptive ideas are critical if we need to rapidly generate enough knowledge for a fast-growing problem. The traditional route for the acceptance of new scientific or analytical methods is acceptance by the global research community and then percolation to Indian academia, and finally to the scientific and technical establishments. The use of synthetic estimates where AQ levels are estimated by merging two or more data is a case in point.[5]

Disruptive ideas are critical if we need to rapidly generate enough knowledge for a fast-growing problem.

Emerging analytical needs will require the use of synthetic estimates to fill in the large data gaps especially those related to coverage of the large landmass and thousands of small and large cities. For instance, though remote sensing data can cover a large geographical expanse, it may not be covering it frequently or precisely enough.  To put it in another way, in-situ data are spatially discontinuous but temporally continuous and satellite data are opposite. We need to combine them. This is already being done globally well-recognized studies (See for instance Shaddick et al., 2018) and needs to be done specifically for India as well.[6] 

Moreover, though the protocols for such estimates may not be unique, data platforms need to have the facilities for researchers to create such estimates using their own methods, using a certain minimum set of best practices. 

Information channels should not be driven by individual interests but by a well-defined process or investigation and analysis. 

While R&D, experiments and pilots are being attempted globally as well as in India, comprehensive and comparative critiques of various emerging technology options are required for policymakers, judiciary as well as potential funders.  Information channels should not be driven by individual interests but by a well-defined process or investigation and analysis. 

Data Platform and Wider-Coverage

A comprehensive data platform is one that is able to put together information from all the sources, cover all important AQ related activities, have universal geographical coverage, and be frequently updated and well maintained. Moreover, various aspects of AQ sometimes get left out in research and these include impact on specific demographic segments (such as low-income households), areas (for example rural areas), and pollutants (such as those originating from informal sector manufacturing). A comprehensive data platform would be able to incorporate all such information and data and also enable access to research on AQ and its many dimensions.

An Environmental Data Platform

India requires a well-developed data management protocol at state/regional as well as national levels. These data centres would require systemically composed and linked databases on pollutants, meteorology and emissions. At the same time metadata needs to be carefully collated and made easily accessible to the user. User interface design is another area where current data sources are fairly archaic, easy drag and drop type user interfaces are emerging as the global norm and so should they be in India. It is such a platform that will facilitate monitoring and analysis by a wide cross-section of researchers, students and even laypersons. 

• Research Database: A database of research, whether originating in India or global, needs to be added to such a data platform. For quantitative analysis requires much research on other experiences, and such a database will be able to facilitate this work. There is much research that would be required in various domains related to the environment and AQ. Some areas are identified in this monograph as well.    
• Environment Data Protocols: The agencies within the government such as the National Statistical Survey Office (NSSO) and Central Statistical Organisation (CSO) are more oriented towards socio-economic or economic data. The CSO has started to bring out a periodical on environmental data, but it is largely a collation of data that is already being collected by different institutions.[7] The environment ministry or the CPCB does not currently have the statistical or organisational capacity to develop such protocols in-house. But this is something that is a core function and needs to be done within the CPCB and State PCBs. 

The environment ministry or the CPCB does not currently have the statistical or organisational capacity to develop such protocols in-house. But this is something that is a core function and needs to be done within the CPCB and State PCBs.

• Chief Environment Data Officer: There are many types of data (for instance data on working trips collected by Registrar General of India) that can have great use for environmental research. A Chief Data Officer or Chief Statisticians Office that is able to motivate varied government entities to collect environment-related information as well as put together a comprehensive data platform, both for governments’ internal needs and for the public at large, needs to be recommended. For coordination in data is a critical component of the emerging world, and whether it is multiple government organizations, independent regulators, communities, industry or even individuals, the world of data in the future is all about coordination and platforms that enable such coordination. The presence of interactive platforms be they offline such as seminars, online media, and print journals on new technologies are key inputs for rapid innovation in this space.

Household Sources of Pollution

Few studies exist in India on indoor household pollution, and the ones that do, reveal a rich set of insights on the level as well as impact. A recently published study, for instance, found that adequate control of indoor health pollution could get a national average of pollution levels in India to be below Indian annual standards.[8] Indoor pollution has many dimensions, including cooking fuel being used, interior design, lack of ventilation, thermal conditions, length of exposure, stove design, etc. Moreover, household chemicals are increasingly being used widely in India as well and these include for cleaning, hygiene, odour management, pest control etc; each of these can be potentially large contributors to indoor pollution.

Standards for indoor air quality are yet to be developed for India.

Therefore, while indoor air pollution may have fallen with the fall of biomass-based cooking, there is a considerable distance yet to be covered, and it may increase again with the greater use of synthetic materials and household chemicals. The NMVOCs emissions in India are expected to increase by 25% in 2030, which has implications over outdoor and indoor air quality. At the same time, there are few scientific studies on household plants and their impact on indoor AQ. Furthermore, though outdoor the AQ standards that do exist are for outdoors, and those for indoor air quality are yet to be developed.

Expanded coverage

Little is understood about AQ levels in a range of areas. For instance, rural areas are assumed to be less polluted than urban areas, even though practices such as crop burning, use of agriculture chemicals, tilled lands with loose soil, increasing use of diesel for transport on agriculture, all would be impacting air quality in significant ways. Similarly, as per one classification, India can be divided into a country of 7 climatic zones, and a data platform that recognizes such underlying factors will help the cause of AQ research. It is expected that most serious pollution abatement strategies would need to be done at a regional level, and issues such as secondary particle formation, interaction with terrain, and nature of air movements need to be well understood at a regional level.

Hot Spots

There are many types of pollution hotspots that include highly dense markets, eateries with biomass stoves, construction sites, industrial and power plants with weak emission management practices, etc. Hotspot monitoring is possible both remotely and using on-site monitoring equipment. Similarly, traffic congestion is rising across the country and is expected to spread further over the next few years, but a greater understanding of the extent of pollution that it causes is required. Residential areas close to major traffic corridors or at crossings with more dense and slower traffic are likely to be more pollution-prone, but the extent is not so well understood. Though a few studies, however, find that such locations are pollution hotspots with significant potential health impact, more studies would help ascertain the extent better. 

The Underprivileged

An inventory of how and what different income segments contribute to emissions can help policy design in many different ways…. informal sector activities should be incorporated in such a comprehensive data platform. 

Though pollution affects all, it is evident that it affects the poor the most. For one access to healthcare is always limited for those less able to afford it. Secondly, the lowest income segments have lesser access to knowledge and means of avoiding exposure, the health impact of which is likely to be worse. Even on the generation side, an inventory of how and what different income segments contribute to emissions can help policy design in many different ways and therefore informal sector activities should be incorporated in such a comprehensive data platform. 

Emission Inventories and Source Attribution

An emission inventory (EI) is an accounting of the pollutants discharged. It logs the types and physical quantity of pollutants discharged from each polluting activity over a specific area and time period. The objective is to estimate the discharge as close to the discharge point as possible. As opposed to ambient pollution which attempts to measure the pollutants present in the atmosphere. Source attribution is the process of assigning the specific source of the pollution through various means including combinations of chemical/physical analysis of the pollutant and the use of emissions inventory. Currently, there is a lack of all three which is reflected in the lack of adequate knowledge inputs being available to policymakers and other decision-makers.

The problem of source apportionment studies cannot be over-emphasized. The IIT Kanpur study is much referred to, and there are other studies that preceded and followed it, but these are Delhi focused, other metro cities, as well as regions, also need to be well covered, their results analysed and validated, for there remains significant uncertainty related to source apportionment.[9] 

Though very frequent source attribution studies may not be required, it is still important to have some done at regular intervals across different climatic zones as technologies and economic activities do change constantly in a fast-growing economy such as India. And for that, a protocol for a standardized emission inventory (EI) needs to be developed specifically for India (though global ones do exist). Based on this, a robust emissions inventory needs to be created at the national level as well as for some of the larger cities including those in the northern plains. 

Though usage of a single emissions inventory need not be mandatory, having a standardized one would help in the comparability of studies.

Though usage of a single emissions inventory need not be mandatory, having a standardized one would help in the comparability of studies. For instance, IIT (Bombay), TERI (New Delhi), Indian Institute of Tropical Meteorology (Pune), all reportedly have their own inventory which presumably varies significantly across institutions. Also, the use of internationally developed emission factors for the estimation of emissions can sometimes lead to large errors in the results. TERI for example, reportedly has a national air inventory for the year 2011 and is now updating it with samples drawn from cities across India and also developing India specific emission factors for agriculture residue burning, refuse burning, road dust and industries. Contrast with Europe where there is a single EI guidance that is followed by all countries, who are therefore using similar methods for estimating emissions. In other words, a single inventory may not be the solution for India, however, one standardized inventory is required, while institutions can develop theirs independently. The latter would enable cross-checking and validating the former. The standardization and having a single inventory are critical as that will enable interaction around a common data language. However, as important is innovation and experimentation with data, and that is possible when there are institutions and researchers who are working independently and in parallel. Whether it is conducted through a single organization or through public academic discussion through journals and other methods of interaction, interactive portals are important for experimentation and innovation. The NGT action plan given to non-attainment cities also calls for developing an emissions inventory. 

Further, there are many fuels or technologies which in a sense are unique to India and whose emissions factors may not be available from studies originating in western countries – PET coke, power oil, burning of reused edible oil, furnace oil, are some examples. Also, the informal sector uses many technologies where fuels are sub-optimally burnt, but little is understood of their emissions factors.

Knowledge of the components of particulate matter, therefore, will better help identify the specific sources and help design superior solutions.

In addition, while it is well understood that particulate matter is a major issue in terms of both extent of pollution and its impact on health, the components of particulate matter vary over space and time. Latest studies are finding that about half of the particulate matter comprises of secondary particles. That is particles that have origins in sulphur, nitrogen or other volatile organic compound gases. Knowledge of the components of particulate matter, therefore, will better help identify the specific sources and help design superior solutions.[10] Moreover, given the different climatic zones in the country, whether it is source apportionment or EI, a set of climatic zones need to be identified and such data and parameters need to be put together for each of these zones. Some understanding of seasonality and how the time of the year affects the data also need to be better understood at a regional/zonal level. 

It is well understood that India need not over-invest in EIs, but a basic understanding of contributory sources will facilitate more nuanced policymaking. Moreover, inter-temporal changes would also affect emissions and therefore the EI exercise would need to be done periodically though not necessarily frequently. Another alternative of source apportionment at regional/national scale is ‘subtraction approach’. A chemical transport model with all sources is run and then one is subtracted, the difference reveals the contribution of that particular source. This type of approaches also depends on the representativeness of the inventories as well as the model configuration (how efficiently the model is able to handle complex chemistry. This is a big gap in India.

The state will have to take up the responsibility of developing and maintain standardized inventory either inhouse or supporting an external entity.

The CPCB is the most likely organization for evolving and maintaining and updating such protocols every few years. Whatever be the organization, the state will have to take up the responsibility of developing and maintain standardized inventory either inhouse or supporting an external entity.

References:

[1] National Air Quality Monitoring Programme, Central Pollution Control Board

[2] Office of the Registrar General & Census Commissioner India, Ministry of Home Affairs, Government of India

[3] National Physical Laboratory (NPL), is reported to be developing an indigenous certification facility for air pollution monitoring equipment. https://www.livemint.com/news/india/india-to-develop-own-certification-facility-for-air-pollution-monitoring-equipme-1556561927930.html

[4] IIT Delhi is working with the CPCB and setting up a PM2.5 database for the entire country at 1 km resolution; we would naturally expect this to be expanded to cover other pollutants such as Ozone, Sox, Nox, VOCs etc. once some standardization of methods occurs.

[5] Based on the measurements carried out at the existing monitoring stations spatial air quality maps can be developed with fewer resources and can be made publicly available on-line in an almost real-time basis. These maps not only provide air quality values at all locations in the city but can also be useful in assessing the exposure of pollutants to the residing population and also help in identifying hot spots. This can lead to enhanced sensitization of the general public and other stakeholders and will also help the policymakers to adjudge the impact of any interventions they make on spatial air quality levels in the whole city. The recently developed Indian Children’s Activity Ratings Mark 1 (ICARE1), for instance, can then be used by each school to devise the specific physical activity children in the school can undertake. Thus, protecting health while enabling play.

[6] Shaddick et. al., “Data Integration for the Assessment of Population Exposure to Ambient Air Pollution for Global Burden of Disease Assessment”, Environ. Sci. Technol. 2018, 52, 16, 9069-9078

[7] EnviStats 2018, Ministry of Statistics and Programme Implementation, Government of India

[8] Indian annual ambient air quality standard is achievable by completely mitigating emissions from household sources, Sourangsu Chowdhary, Sagnik Dey, Sarath Guttikunda, Ajay Pillarisetti, Kirk R. Smith, Proceedings of the National Academy of Sciences, April 2019

[9] Comprehensive Study on Air Pollution and Green House Gases (GHG) in Delhi, Mukesh Sharma, Onkar Dikshit, Indian Institute of Technology, Kanpur, 2016

[10] Even though it is said that the PM level in Delhi is alarmingly high but if we look at the composition of the PM in Delhi and PM in the USA, the PM in Delhi contains majorly the dust particles whereas in the USA it is majorly sulphur pollutant, and PM containing dust is not deadly while PM with secondary particulates can be. So it is important to look at AQ in terms of health also and not just absolute concentration.