Dear Readers,
This year’s theme for the World Environment Day celebrations is on Air Pollution. I am sharing some of my thoughts and musings focusing on air quality monitoring.
Yours Truly
Ministry of Environment, Forests and Climate Change (MoEF&CC) in India launched National Cleaner Air Programme (NCAP) few months before the General Elections. Air pollution found a place in the election manifestos of National Democratic Alliance (NDA) and United Progressive Alliance (UPA).
The NCAP is a mid-term, five-year action plan that includes collaborative, multi-scale and cross-sectoral coordination between relevant Central ministries, State governments and local bodies. The objectives of the plan align with existing policies and programs, including the National Action Plan on Climate Change, initiatives on electric vehicles, the Smart Cities Mission among others. The NCAP also facilitates partnerships with multi and bilateral international organizations, philanthropic foundations, and leading technical institutions, experts from industry, academia, and civil society to accomplish its goals. The NCAP is thus a well-structured program and is cast in the style of Sabka Saath (i.e. working together and helping each other)
A budget amounting to Rs 6370 million has been set aside for aiding implementation of the programme. The document lays down specific targets and timelines for each initiative listed under the programme. A budget of Rs 3000 million has been allocated for two years to tackle air pollution across 102 cities, that have been identified by the Central Pollution Control Board (CPCB) for not meeting the ambient air quality standards. See the outline of NCAP as depicted below
The NCAP lays down a comprehensive strategic framework for enhanced monitoring of air quality. Augmentation of existing air quality monitoring network by increasing number of existing manual and Continuous Ambient Air Quality Monitoring Stations (CAAQMS), introducing rural air quality monitoring stations, identifying alternative technology for real-time monitoring network and augmenting capabilities of existing monitoring stations to measure PM2.5 concentration, are integral components of the strategy framework.
At the present time, about 150 real time and 731 manual stations are installed in 70 cities across the country, 48 of them in the national capital alone! In the NCAP it is envisaged that the real time ambient air quality monitoring system will be expanded from 150 to 450 and the manual monitoring stations to 1,500 by 2024.
CPCB vide its letter No. B-29016/04/06PCI-1/5401 dated 05.02.2014 issued directions for installation of online effluent quality and Continuous Emission Monitoring Systems (CEMS) to track the discharges of pollutants. This directive is supported by the Guidelines on CEMS.
It is not surprising that the market for CAAQMS as well as CEMS has been rapidly growing in India. Industries, Urban Local Bodies (ULBs) and Pollution Control Boards (PCBs) have done major investments. Unfortunately, in most cases, these instruments do not seem to work and there are significant downtimes or instances of erroneous reporting of data. Long spells of missing data are not uncommon. There is also a challenge of spares and availability of local expertise as the instruments are mostly imported or assembled. Further, the accuracy of this data has been a concern, as many of these instruments suffer from issues of calibration and certification. The local manufacturing and support capabilities are poor.
In addition, the Interest on using low cost air quality sensors is rising, especially to monitor indoor air quality. This market is currently unregulated as we do not have indoor air quality standards – but we expect a steep rise in the sale of low-cost air quality sensors – that cost as little as Rs 5000 and can be shopped on Amazon! But how reliable are the measurements from these low air quality monitoring sensors is a question. Readers may like to refer to the article “The Changing Paradigm of Air Pollution Monitoring” by Emily G. Snyder and her co-workers to get an overview of low-cost air quality sensors.
Most of the air quality data is generated by instruments that have been manufactured abroad and certified by international agencies. High humidity levels, dusty weather and temperature variations in India could impact their long-term functioning. The National Physical Laboratory (NPL), one of the country’s premier research and development units, is developing India’s own certification facility for air pollution monitoring equipment. The move could boost the ‘Make in India’ initiative as NPL expects demand for such equipment to soar as part of the NCAP. The process is not yet mandatory but may be made a regulatory requirement.
NPL is reportedly awarded a project by MoEF&CC over two years with a proposed budget outlay of nearly Rs 590 million. The local certification would not only help bring down costs, but also improve the measurement of air pollution and help scrutinize the data that is generated. We need agencies like NPL and NEERI to take on certification of indoor as well as outdoor low-cost air quality sensors. If this step is not taken in time, then we will witness a chaos as far as air quality and emission data are concerned. Let us see more of indigenous and locally tested CAAQMS and CEMS in the NCAP.
But do we analyse the air quality data that we collect at the CAAQMS and CEMS at all? Most of the air quality data transmitted to the Pollution Control Boards (PCBs) lies in the coffins. The staff at PCBs are not just equipped with the tools and skills that are required for analysis and interpretation of air quality data. Installing CAAQMS and CEMS has simply become a tick mark while checking the “compliance” and transmission of data to the PCBs has become only a ritual. We must resolve this stark and sad reality if we want to see “returns” on investments made on air quality monitoring and achieve the goals of NCAP. There is so much possible to interpret if we apply the rigor of analytics to our CAAQMS and CEMS data. I have been training staff and analysing the CAAQMS data collected by PCBs and the results have been very exciting and encouraging. We need several such training programs supported by on-line dashboard to provide support and build capacities at the PCBs.
But now let us revisit the basics. We operate nation-wide air quality monitoring programs for three principle objectives
- Detect violations
- Identify trends
- Assess exposure to health
Addressing these three objectives is important as it helps us in assessing the effectiveness of the air quality action plans and adapt or augment them as necessary. I am not sure whether the NCAP is addressing the “design of the real time ambient air quality monitoring networks” to address the above objectives. Here, siting the CAAQMS plays an important role. I am not sure how many CAAQMS in India will pass through the “site audits”.
Let me delve more on the third important objective of assessing exposure to health that is perhaps the foundation of NCAP. Today, there is a lack of indigenous studies establishing the correlation between exposure to air pollution and human health. To understand and address India’s air pollution crisis, refinement of local epidemiologic evidence is needed. The research base in this area is steadily expanding but at a much slower pace. A dearth of long-term air pollution epidemiologic cohort research in India is certainly of concern. Under the NCAP, a high-level apex committee and working group has been constituted under the Indian Council of Medical Research and the MoEF&CC to overcome this deficit. This committee should address and lay down protocols for monitoring network design that will address the interest of exposure assessment apart from trends and compliance.
Many cohort studies have found associations between long-term exposure to air pollution and various health endpoints by employing air pollution data from regulatory monitoring networks operated by governments. However, these regulatory monitoring networks are designed primarily to monitor air quality and regulate pollution sources, rather than to evaluate the health effects of air pollution. Thus, air pollution measurements collected in regulatory monitoring networks may not sufficiently represent the variability of air pollution concentrations across people’s residences. A recent research paper published by Kyung-Duk Min and his co-workers in Korea on Air Pollution Monitoring Design for Epidemiological Application in a Densely Populated City may interest the readers.
NCAP may also give a good opportunity to include monitoring of Short Lived Climate Pollutants (SLCPs). SLCPs remain in the atmosphere for a much shorter period of time than carbon dioxide (CO2), yet their potential to warm the atmosphere can be many times greater. Certain short-lived climate pollutants are also dangerous air pollutants that have harmful effects for people, ecosystems and agricultural productivity.
The SLCPs include black carbon, methane, tropospheric ozone and hydrofluorocarbons that are the most important contributors to the man-made global greenhouse effect after carbon dioxide, responsible for up to 45% of current global warming. The clean air action plans envisaged in the NCAP should include actions to reduce emissions of SLCP.
Finally, communicating air quality data to different stakeholders is an important but daunting task. The NCAP proposes setting up of an Air Information Centre that would analyse and disseminate monitored air quality data with an Air Quality Forecasting system.
While reporting, format of AQI has now become a practice, but we must be careful that the messages that multiple websites give on the status of Air Quality. I am illustrating below two screens that indicate air quality in Solapur in Maharashtra on Monday June 3 at 7 pm as reported by two websites viz. CPCB and AQICN. You would notice differences reported in the pollutant concentrations (see Max, Min and Average) and the differences in the overall interpretation – i.e. one showing “satisfactory” and other showing “unhealthy conditions” – mainly because of differences in the structure of AQI. Readers may like to see a comparison. So, what should the citizens “believe” becomes a question.
It is a high time therefore that we pull up our socks and address the challenge of “quality data” in implementing NCAP. We need a good baseline and we should be addressing all the three objectives of trends, compliance and exposure. This should be done at the level of detail that the subject deserves.
We don’t want to be just data rich – and yet be data poor.
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In the 80s, TOI used to report Air Pollution and water pollution levels in Baroda and Bombay too. My uncle, who was a Pathologist, used to say that nobody is doing anything, faecal matter levels for Bombay water supply used to be orders if magnitude above WHO permissible limits. Air Quality at Baroda was similar, for SO2 levels, particulate matter etc. Has there been any change in implementing measures to reduce such levels of Pollution in Air and Water? I read that like Paris, Delhi has odd/even number plate car restrictions for driving when Ozone levels are above a permissible threshold, but implementing this is impossible from news accounts. I was present in Paris in 1997 ( around May) when they first implemented this measure, and all Public Transport was free that day.
On water pollution levels – here in my Houston Area, the Public Municipal district Authorities actually mail out a report to all residents annually, showing what levels ( Pb, etc) have been measured and trend, along with explanations and remedial work. Yes, the US also has pockets of Pb contamination due to aging water infrastructure, and in the case of Flint, Michigan, it was eye-opener!