South Asian megacities are strong sources of regional air pollution. Delhi is a key hotspot of health- and climate-impacting black carbon (BC) emissions, affecting environmental sustainability in densely populated northern India. Effective mitigation of BC impact is hampered by highly uncertain emission source estimates. Here, we use dual-carbon isotope fingerprints (δ13C/∆14C) of BC to constrain the seasonal source variability in Delhi. These measurements show that lower BC concentrations in summer are predominantly from fossil fuel sources (~83%). However, large-scale open burning of post-harvest crop residue/wood in nearby rural regions is contributing to severe haze pollution in Delhi during winter and autumn (~42 ± 17%). Hence, the common conception that megacities affect their surroundings is here amended or seasonally reversed. Therefore, to combat the severe air pollution problems in Delhi and the environmental quality of northern India, current urban efforts need to be complemented with countryside regional mitigation.
This is a preview of subscription content, access via your institution
Open Access articles citing this article.
Communications Earth & Environment Open Access 01 April 2022
On the widespread enhancement in fine particulate matter across the Indo-Gangetic Plain towards winter
Scientific Reports Open Access 03 April 2020
Subscribe to Nature+
Get immediate online access to the entire Nature family of 50+ journals
Subscribe to Journal
Get full journal access for 1 year
only $9.92 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Get time limited or full article access on ReadCube.
All prices are NET prices.
The observational data that support the findings of this study are available in the Bolin Centre Database (http://bolin.su.se/data/) and from the corresponding author upon request.
Jerrett, M. Atmospheric science: the death toll from air-pollution sources. Nature 525, 330–331 (2015).
Lelieveld, J., Evans, J., Fnais, M., Giannadaki, D. & Pozzer, A. The contribution of outdoor air pollution sources to premature mortality on a global scale. Nature 525, 367–371 (2015).
Gautam, R., Hsu, N. C., Kafatos, M. & Tsay, S. C. Influences of winter haze on fog/low cloud over the Indo-Gangetic plains. J. Geophys. Res. 112, D05207 (2007).
Singh, R. P. & Kaskaoutis, D. G. Crop residue burning: a threat to south asian air quality. Trans. Am. Geophys. Union 95, 333–334 (2014).
Kaskaoutis, D. G. et al. Effects of crop residue burning on aerosol properties, plume characteristics, and long-range transport over northern India. J. Geophys. Res. 119, 5424–5444 (2014).
Air Quality Guidelines: Global Update 2005 (World Health Organization, 2006).
Beekmann, M. et al. In situ, satellite measurement and model evidence on the dominant regional contribution to fine particulate matter levels in the Paris megacity. Atmos. Chem. Phys. 15, 9577–9591 (2015).
Sharma, S. et al. Breathing Cleaner Air: Ten Scalable Solutions for Indian Cities (World Sustainable Development Summit, New Delhi, 2016).
Ramanathan, V. & Carmichael, G. Global and regional climate changes due to black carbon. Nat. Geosci. 1, 221–227 (2008).
Bond, T. C. et al. Bounding the role of black carbon in the climate system: a scientific assessment. J. Geophys. Res. 118, 5380–5552 (2013).
Sehgal, M. & Gautam, S. K. Odd even story of Delhi traffic and air pollution. Int. J. Environ. Stud. 73, 170–172 (2016).
Ramanathan, V. et al. Bending the curve: ten scalable solutions for carbon neutrality and climate stability. Collabra 2, 15 (2016).
Shindell, D. et al. Climate, health, agricultural and economic impacts of tighter vehicle-emission standards. Nat. Clim. Change 1, 59–66 (2011).
Menon, S., Hansen, J., Nazarenko, L. & Luo, Y. Climate effects of black carbon aerosols in China and India. Science 297, 2250–2253 (2002).
Evan, A. T., Kossin, J. P., ‘Eddy’ Chung, C. & Ramanathan, V. Arabian Sea tropical cyclones intensified by emissions of black carbon and other aerosols. Nature 479, 94–97 (2011).
Gustafsson, Ö. & Ramanathan, V. Convergence on climate warming by black carbon aerosols. Proc. Natl Acad. Sci. USA 113, 4243–4245 (2016).
Bosch, C. et al. Source-diagnostic dual-isotope composition and optical properties of water-soluble organic carbon and elemental carbon in the South Asian outflow intercepted over the Indian Ocean. J. Geophys. Res. 119, 11743–11759 (2014).
Gustafsson, Ö. et al. Brown clouds over South Asia: biomass or fossil fuel combustion?. Science 323, 495–498 (2009).
Budhavant, K. et al. Radiocarbon-based source apportionment of elemental carbon aerosols at two South Asian receptor observatories over a full annual cycle. Environ. Res. Lett. 10, 064004 (2015).
Tiwari, S. et al. Diurnal and seasonal variations of black carbon and PM2.5 over New Delhi, India: influence of meteorology. Atmos. Res. 125–126, 50–62 (2013).
Srinivas, B. & Sarin, M. M. PM2. 5, EC and OC in atmospheric outflow from the Indo-Gangetic Plain: temporal variability and aerosol organic carbon-to-organic mass conversion factor. Sci. Total Environ. 487, 196 (2014).
Rastogi, N., Singh, A., Singh, D. & Sarin, M. Chemical characteristics of PM2. 5 at a source region of biomass burning emissions: evidence for secondary aerosol formation. Environ. Pollut. 184, 563–569 (2014).
Bikkina, S. et al. Carbon isotope-constrained seasonality of carbonaceous aerosol sources from an urban location (Kanpur) in the Indo-Gangetic Plain. J. Geophys. Res. 122, 4903–4923 (2017).
Ram, K., Sarin, M. M. & Tripathi, S. N. Temporal trends in atmospheric PM2.5, PM10, elemental carbon, organic carbon, water-soluble organic carbon, and optical properties: impact of biomass burning emissions in the indo-gangetic plain. Environ. Sci. Technol. 46, 686–695 (2012).
Arola, A. et al. Direct radiative effect by brown carbon over the Indo-Gangetic Plain. Atmos. Chem. Phys. 15, 12731–12740 (2015).
Rengarajan, R., Sarin, M. & Sudheer, A. Carbonaceous and inorganic species in atmospheric aerosols during wintertime over urban and high-altitude sites in North India. J. Geophys. Res. 112, D21307 (2007).
Venkataraman, C., Habib, G., Eiguren-Fernandez, A., Miguel, A. H. & Friedlander, S. K. Residential biofuels in South Asia: carbonaceous aerosol emissions and climate impacts. Science 307, 1454–1456 (2005).
Kirillova, E. N. et al. 13C‐and 14C‐based study of sources and atmospheric processing of water‐soluble organic carbon (WSOC) in South Asian aerosols. J. Geophys. Res. 118, 614–626 (2013).
Yan, C. et al. Important fossil source contribution to brown carbon in Beijing during winter. Sci. Rep. 7, 43182 (2017).
Widory, D. Combustibles, fuels and their combustion products: a view through carbon isotopes. Combust. Theor. Model. 10, 831–841 (2006).
Cao, J.-J. et al. Stable carbon isotopes in aerosols from Chinese cities: influence of fossil fuels. Atmos. Environ. 45, 1359–1363 (2011).
Agnihotri, R. et al. Stable carbon and nitrogen isotopic composition of bulk aerosols over India and northern Indian Ocean. Atmos. Environ. 45, 2828–2835 (2011).
Andersson, A. et al. Regionally-varying combustion sources of the January 2013 severe haze events over eastern China. Environ. Sci. Technol. 49, 2038–2043 (2015).
Marrapu, P. et al. Air quality in Delhi during the Commonwealth Games. Atmos. Chem. Phys. 14, 10619–10630 (2014).
Badarinath, K., Kharol, S. K. & Sharma, A. R. Long-range transport of aerosols from agriculture crop residue burning in Indo-Gangetic Plains—a study using LIDAR, ground measurements and satellite data. J. Atmos. Sol. Terr. Phys. 71, 112–120 (2009).
Bikkina, S. et al. Dual carbon isotope characterization of total organic carbon in wintertime carbonaceous aerosols from northern India. J. Geophys. Res. 121, 4797–4809 (2016).
Liu, T. et al. Seasonal impact of regional outdoor biomass burning on air pollution in three Indian cities: Delhi, Bengaluru, and Pune. Atmos. Environ. 172, 83–92 (2018).
Vadrevu, K. P., Ellicott, E., Badarinath, K. V. S. & Vermote, E. MODIS derived fire characteristics and aerosol optical depth variations during the agricultural residue burning season, north India. Environ. Pollut. 159, 1560–1569 (2011).
Nair, V. S. et al. Wintertime aerosol characteristics over the Indo-Gangetic Plain (IGP): Impacts of local boundary layer processes and long-range transport. J. Geophys. Res. 112, D13205 (2007).
Gogoi, M. M., Suresh Babu, S., Krishna Moorthy, K., Manoj, M. R. & Chaubey, J. P. Absorption characteristics of aerosols over the northwestern region of India: distinct seasonal signatures of biomass burning aerosols and mineral dust. Atmos. Environ. 73, 92–102 (2013).
Raatikainen, T. et al. The effect of boundary layer dynamics on aerosol properties at the Indo-Gangetic plains and at the foothills of the Himalayas. Atmos. Environ. 89, 548–555 (2014).
Zhang, Y. L. et al. Fossil vs. non-fossil sources of fine carbonaceous aerosols in four Chinese cities during the extreme winter haze episode of 2013. Atmos. Chem. Phys. 15, 1299–1312 (2015).
Liu, J. et al. Source apportionment and dynamic changes of carbonaceous aerosols during the haze bloom-decay process in China based on radiocarbon and organic molecular tracers. Atmos. Chem. Phys. 16, 2985–2996 (2016).
Zhang, Y.-L. et al. Source apportionment of elemental carbon in beijing, china: insights from radiocarbon and organic marker measurements. Environ. Sci. Technol. 49, 8408–8415 (2015).
Zhang, Y.-L. et al. Fossil and nonfossil sources of organic and elemental carbon aerosols in the outflow from northeast china. Environ. Sci. Technol. 50, 6284–6292 (2016).
Chen, B. et al. Source forensics of black carbon aerosols from China. Environ. Sci. Technol. 47, 9102–9108 (2013).
Fang, W. et al. Divergent evolution of carbonaceous aerosols during dispersal of east asian haze. Sci. Rep. 7, 10422 (2017).
Fang, W. et al. Dual-isotope constraints on seasonally resolved source fingerprinting of black carbon aerosols in sites of the four emission hot spot regions of china. J. Geophys. Res. 123, 11735–11747 (2018).
Huang, R.-J. et al. High secondary aerosol contribution to particulate pollution during haze events in China. Nature 514, 218 (2014).
Liu, J. et al. Source apportionment using radiocarbon and organic tracers for PM2. 5 carbonaceous aerosols in Guangzhou, South China: contrasting local- and regional-scale haze events. Environ. Sci. Technol. 48, 12002–12011 (2014).
Birch, M. E. & Cary, R. A. Elemental carbon-based method for monitoring occupational exposures to particulate diesel exhaust. Aerosol. Sci. Technol. 25, 221–241 (1996).
Winiger, P., Andersson, A., Yttri, K. E., Tunved, P. & Gustafsson, Ö. Isotope-based source apportionment of EC aerosol particles during winter high-pollution events at the zeppelin observatory, svalbard. Environ. Sci. Technol. 49, 11959–11966 (2015).
Zencak, Z., Elmquist, M. & Gustafsson, Ö. Quantification and radiocarbon source apportionment of black carbon in atmospheric aerosols using the CTO-375 method. Atmos. Environ. 41, 7895–7906 (2007).
Graven, H. D., Guilderson, T. P. & Keeling, R. F. Observations of radiocarbon in CO2 at seven global sampling sites in the Scripps flask network: Analysis of spatial gradients and seasonal cycles. J. Geophys. Res. 117, D02302 (2012).
Stein, A. et al. NOAA’s HYSPLIT atmospheric transport and dispersion modeling system. Bull. Am. Meteorol. Soc. 96, 2059–2077 (2015).
R Core Team. _R: A Language and Environment for Statistical Ccomputing_ (R Foundation for Statistical Computing, Vienna, 2013); http://www.R-project.org/.
This work was funded by the Swedish Research Council (FORMAS grant no. 214-2009-970), the Swedish Energy Agency (STEM grant no. 35450-2), and the Swedish Research Council VR (Distinguished Professor Grant no. 2017-01601). The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (http://www.ready.noaa.gov) used in this study.
The authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Bikkina, S., Andersson, A., Kirillova, E.N. et al. Air quality in megacity Delhi affected by countryside biomass burning. Nat Sustain 2, 200–205 (2019). https://doi.org/10.1038/s41893-019-0219-0
This article is cited by
Communications Earth & Environment (2022)
Anthropogenic Land Use and Land Cover Changes—A Review on Its Environmental Consequences and Climate Change
Journal of the Indian Society of Remote Sensing (2022)
Gridded distribution of total suspended particulate matter (TSP) and their chemical characterization over Delhi during winter
Environmental Science and Pollution Research (2022)
Meteorology and Atmospheric Physics (2022)
Current Pollution Reports (2022)