Long-term trends in urban NO2 concentrations and associated pediatric asthma incidence: estimates from global datasets
Susan C. Anenberg1*, Arash Mohegh1*, Daniel L. Goldberg1,2, Gaige H. Kerr1, Michael Brauer3,4, Katrin Burkart3, Perry Hystad5, Andrew Larkin5, Sarah Wozniak3, Lok Lamsal6
1Milken Institute School of Public Health, George Washington University, Washington, DC, USA;
2Energy Systems Division, Argonne National Laboratory, Washington, DC, USA; 3 Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, USA; 4 University of British Columbia, Vancouver, BC, Canada; 5 Oregon State University, Corvallis, OR, USA; 6 NASA Goddard Space Flight Center, Greenbelt, MD, USA
* These authors contributed equally to this work.
Background: Combustion-related nitrogen dioxide (NO2) air pollution is associated with pediatric asthma incidence. We estimated global surface NO2 concentrations consistent with the Global Burden of Disease Study for 1990-2019 at 1km resolution, and trends in concentrations and attributable pediatric asthma incidence in 13,189 cities from 2000-2019.
Methods: We scaled an existing surface annual average NO2 concentrations dataset for 2010-2012 from a land use regression model (based on 5,220 NO2 monitors in 58 countries and land use variables) to other years using NO2 column densities from satellite and reanalysis datasets. We applied these concentrations to epidemiologically-derived concentration-response factors, population, and baseline asthma rates to estimate NO2-attributable pediatric asthma incidence.
Results: Our preliminary results indicate that 1.85 million (95% uncertainty interval: 0.83 – 2.4) new pediatric asthma cases may have been attributable to NO2 in 2019, two-thirds of which occurred in urban areas. The fraction of pediatric asthma incidence that is attributable to NO2 in urban areas declined from 20% in 2000 to 16% in 2019. Attributable fractions dropped in High-income cities (-41%), Latin America and Caribbean (-16%), Central Europe, Eastern Europe, and Central Asia (-13%), and Southeast Asia, East Asia, and Oceania (-6%), and rose in South Asia (+23%), Sub-Saharan Africa (+11%), and North Africa and Middle East (+5%). The relative importance of NO2 concentrations, pediatric population size, and asthma incidence rates in driving these changes differs regionally.
Conclusions: Despite improvements in some regions, combustion-related NO2 pollution continues to be an important contributor to pediatric asthma incidence globally, particularly in cities.