NEWSLETTER 02
AakashNo.

23 June, 2020

Newsletter for An Interdisciplinary Study toward Clean Air, Public Health and Sustainable Agriculture: The Caseof Crop Residue Burning in North India

How might the unexpected change in airquality caused by the lockdown in Indiachange people’s future behaviour?
By Sachiko Hayashida (Aakash Project Leader) and Prakhar Misra (Aakash Project Researcher)
Research Institute for Humanity and Nature (RIHN)

The Aakash Project commenced on April 1, 2020 at the Research Institute of Humanity andNature (RIHN) in Kyoto, Japan (https://www.chikyu.ac.jp/rihn_e/project/FS-2019-01.html). The fulltitle of the project is “An Interdisciplinary Study Toward Clean Air, Public Health and Sustainable
Agriculture: The Case of Crop Residue Burning in North India”. We chose the name Aakash, whichis the Hindi word for sky, because this study addresses the air pollution caused by large-scale
post-harvest burning of rice straw in October and November in the states of Punjab and Haryana
in northwestern India. This burning causes severe air pollution in the surrounding areas, mostnotably in the National Capital Region comprising Delhi and its surrounding districts. Someevidence suggests that crop-residue burning negatively affects air quality over the entire IndoGangetic Plain (IGP)[1, 2], demonstrating the weaknesses of current policies on regional airquality, which affects the health and well-being of hundreds of millions of people[3].
Before starting the project, we planned to organize the first India–Japan project conference in
Delhi at the end of March to promote mutual understanding and collaboration between the Indianand Japanese project members and other stakeholders. However, India was placed on lockdown
on March 25 to stop the spread of the coronavirus, and thus we were forced to cancel theconference. Soon after, we heard news reports of clean air in Delhi and other large cities aroundthe world known for their pollution[4,5,6]. It was surprising and rather ironic for us to see the clean
air that we were aiming for before we could even start our project.
Inspired by the sudden appearance of clean air, members of Working Group 2 (WG2), whose
focus is atmospheric research, held online meetings four times in April and into May to quantify thereduction in the emission of air pollutants in Delhi. From these meetings, we decided to begin anew activity, which we named “Mission DELHIS (Detection of Emission Change of air pollutants:Human Impact Studies)”. This activity aims to quantify the reduction in emissions due to thetemporary suspension of anthropogenic pollutant emissions. By comparing the concentrations ofair pollutants before and after the lockdown was instituted, it may be possible to accurately
quantify anthropogenic emissions. In addition, by estimating non-agricultural anthropogenicemissions, it may be possible to determine the contribution of agricultural burning to the total
pollutants emissions. The coronavirus pandemic has presented us with an unexpected opportunity
to conduct a social experiment on a large scale.

Lockdown observed from space
Since the 1990s, research and development of new technologies has made it possible tomeasure air pollutants from space, and today several satellite sensors are used to observe various
air pollutants. Among these pollutants, particulate matter (aerosols) and nitrogen dioxide (NO2) aremajor concerns. The concentration of these pollutants varies according to the degree of emissions
from industrial activity, transportation, and daily activities such as cooking; therefore, we can better
understand the effects of human activity by monitoring the concentrations of these pollutants.
Today, satellite observation not only identifies what is present on the ground, but also reveals what
is happening there.
Beijing was once known for its heavily polluted air, and which caused some athletes to withdraw
from the 2008 Olympics. As a result of the Chinese government’s various measures against air
pollution, the air quality has improved considerably. A satellite sensor, the Ozone Monitoring
Instrument, observed a sudden decline in NO2 concentrations over Beijing in August 2008 when
the Olympics were held[7]. At present, many countries have instituted urban lockdowns and selfquarantine to slow the spread of the coronavirus. As a result, there have been a series of reportsthat NO2 concentrations in large cities such as Paris and Wuhan have declined dramatically during
the lockdown period[8,9].
The Indian capital of Delhi has been called the world’s most heavily polluted city[10]. However,the skies have turned blue as a result of the sudden lockdown, much to the delight of local
residents [11].
We analysed the data obtained by the TROPOMI sensor onboard the European Space Agency
satellite Sentinel-5 Precursor TROPOMI(ESA: http://www.tropomi.eu) and found that NO2 clearlydecreased after the lockdown was instituted (Figure 1). Because air pollutants emitted fromsources such as factories and vehicles are carried by the wind, their concentrations depend on
weather conditions, and thus it is inherently difficult to uniquely associate atmospheric pollutant
concentrations with their source. However, in the case of NO2, it is relatively easy to identify thesource because NO2 has a relatively short atmospheric lifetime and remains close to its emission
source; therefore, the difference between the two images in Figure 1 clearly indicates a reductionin emissions.

Figure 1: (left) Mean NO2 concentration March 2–6, 2020 (before the lockdown), and (right) March
30–April 4, 2020 (during the lockdown). NO2 data was taken from TROPOMI (ESA:
http://www.tropomi.eu).
At present, the members of WG2 are working tirelessly to quantify the reduction inNO2 emissions. In future research, we will use in situ measurements, satellite data, and model
simulations to determine the change in air pollutant concentrations.

Unexpected changes in people’s behaviourOur original project goal was to “explore ways to change people’s behaviour towards sustainableagriculture in Punjab, and towards clean air and improved health outcomes”. When we proposed
this research plan two years ago, the RIHN Research Evaluation Committee doubted the idea thatpeople’s behaviour could be so easily changed. However, the coronavirus pandemic has changed
many aspects of people’s behaviour in a very short time. People’s interest in health, especially
respiratory system disorders, has increased dramatically, and many people have begun wearing
masks. Reports of high mortality from COVID-19 in heavily air-polluted areas [12,13] may also
have come as a shock to many Delhi residents.
Clean air in Delhi has been made possible by this temporary lockdown and the resulting halt ofeconomic activity, but air pollution is expected to return to pre-lockdown levels when the lockdown
is lifted and economic activity resumes. However, the change in people’s behaviour may not be soeasily reversed. People have gradually begun to realize the value of their own health and havebecome aware of the effects of air pollution and its impact on lung function. The practice ofwearing masks in public may become more commonplace. In addition, residents’ experience withclean air and blue skies may have helped them to realize the value of environmental health. Howmuch did the residents of Delhi enjoy having clean air and what did they learn from theexperience?
We are currently planning to conduct a questionnaire survey of residents in Delhi and thesurrounding rural areas. It is important to obtain data that can be observed only now. We should
endeavour to “detect” what people feel at present in addition to the current concentration ofpollutants. We must learn as much as possible while we can, so our motto has become “detection,detection, detection”.
(The original version was released on May 25 at Aakash HP: http://aakash.wp.xdomain.jp)-------------------------------References

1. Kaskaoutis, D. G. et al. (2014), Effects of crop residue burning on aerosol properties, plumecharacteristics, and long-range transport over northern India. Journal of GeophysicalResearch Atmosphere 119, 5424-5444, doi:10.1002/2013JD021357.
2. Sarkar, S. et al. (2018), Crop residue burning in Northern India: Increasing threat to greater
India, Journal of Geophysical Research: Atmospheres, 123(13), 6920-6934,
doi:10.1029/2018jd028428.
3. Sarkar, S., et al. (2018), Increasing health threat to greater parts of India due to crop
residue burning, The Lancet Planetary Health, 2(8), e327-e328, doi:10.1016/s25425196(18)30166-9.
4. Lockdown reduces Delhi pollution; air quality turns 'good' from 'hazardous'-Business Today,
March 27, 2020, https://www.businesstoday.in/latest/trends/lockdown--reduces-delhi-pollution-airquality-turns-good-from-hazardous/story/399397.html
5. Air pollution drops to record low in India following lockdown- Air quality news, March 30, 2020,
https://airqualitynews.com/2020/03/30/air-pollution-drops-to-record-low-in-india-followinglockdown/
6. Coronavirus: India sees blue skies and clean air as a result of the world’s largest lockdown -The
Independent, April 11, 2020, https://www.independent.co.uk/news/world/asia/coronavirus-airpollution-lockdown-a9460841.html
7.Beijing Restrictions Reduce Pollution- NASA earth observatory, December 17, 2008,https://earthobservatory.nasa.gov/images/36195/beijing-restrictions-reduce-pollution

8. Coronavirus lockdown leading to drop in pollution across Europe—ESA, March 27,2020,
https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel5P/Coronavirus_lockdown_leading_to_drop_in_pollution_across_Europe
9. Airborne Nitrogen Dioxide Plummets Over China- NASA earth observatory,March 2, 2020,
https://earthobservatory.nasa.gov/images/146362/airborne-nitrogen-dioxide-plummets-over-china
10. 2019 WORLD AIR QUALITY REPORT Region & City PM2.5 Ranking, IQAir
11. India's air quality has improved so much since the country went on coronavirus lockdown
citizens can now see the Himalyas for the first time in 30 years-Business Insider Australia, April 14,
2020, https://www.businessinsider.com.au/himalayas-seen-from-india-pollution-drop-coronaviruslockdown-2020-4
12.Ogen, Assessing nitrogen dioxide (NO2) levels as a contributing factor to coronavirus (COVID19) fatality, Science of the Total Environment 726 (2020) 138605,
https://doi.org/10.1016/j.scitotenv.2020.138605
13. Wu et al., 2020, medRxiv preprint doi: https://doi.org/10.1101/2020.04.05.20054502(full paper
under review).