Using the Power of Global Air Quality Models
and NCCS Supercomputing Resources, NYU and NASA
Collaborators Create a Novel Index
to Communicate Children’s Respiratory Health Risk
Top row, left to right: NYU Marron Institute collaborators Laura Gladson, Doctoral Researcher; Kevin Cromar, Director of the Health, Environment, and Policy program and Associate Professor; and Marya Ghazipura, Epidemiologist (previous). Bottom row, left to right: NASA collaborators K. Emma Knowland, Atmospheric and Environmental Scientist; Christoph Keller, Atmospheric Scientist; and Bryan Duncan, Earth and Atmospheric Scientist.
The impact of air pollution begins in childhood. Children growing up in urban areas are subjected to higher levels of air pollution and their short and long-term health impacts, and developing countries seldom have the benefit of local air quality alert systems. Air pollution exposures are correlated with a wide range of health threats including asthma and other respiratory illnesses, yet globally 93% of children under the age of 18 are exposed to air pollution above levels recommended by the World Health Organization (WHO).
Extensive research reveals that children are especially susceptible to these effects and have a wide range of adverse health outcomes from poor air quality, with respiratory impacts especially rampant. A recently published WHO report highlights this fact: “The evidence is clear: air pollution has a devastating impact on children’s health.” More than half a million children under the age of 15 died in 2016 due to exposure to air pollution in their immediate environment, mainly children living in low- and middle-income countries with more pollution. The lack of reliable air quality data and risk communication information in these communities and higher levels of air pollution are additional risk factors in the outcome of children’s health.
A new project led by Laura Gladson, a doctoral researcher at the Marron Institute of Urban Management at New York University (NYU), aims at filling this gap by providing air quality risk communication information for cities around the world to better inform local communities and help individuals take steps to protect children's respiratory health.
Gladson and her colleagues at NYU teamed up with air quality and modeling experts at NASA’s Goddard Space Flight Center to conduct a study developing a health index using global air quality models and the high-end computing resources of the Discover supercomputer at the NASA Center for Climate Simulation (NCCS). This index can be used to inform communities, mitigate risk, and improve respiratory health outcomes in children.
The NYU and NASA collaborators used historical daily concentration estimates produced by the Goddard Earth Observing System Composition Forecast system, GEOS-CF, to test a novel health-based air quality index for communicating children’s respiratory risk. GEOS-CF combines the GEOS model with a global 3D model of atmospheric chemistry called GEOS-Chem to produce daily, global 5-day forecasts of atmospheric composition at 0.25 degrees (~25 kilometers) in near real-time.
The complex simulation of global atmospheric chemistry makes GEOS-CF a compute-intense system, requiring 3,510 computer processors to be run for nearly 9 hours on the NCCS’s Discover supercomputer. The total daily output produced by GEOS-CF is approximately 1 terabyte, compressed down to 450 gigabytes. GEOS-CF is developed and maintained by the Global Modeling and Assimilation Office (GMAO) at NASA Goddard, with daily GEOS-CF simulations conducted on Discover.
By analyzing published studies and the relative associations between children’s exposure to air pollution and their health outcomes, Gladson and her colleagues created several variations of an index that uses local concentrations from three key pollutants to produce a single number between 1 and 10 representing the level of risk on a given day. The key pollutants used for each index were fine particulate matter (PM2.5), ground-level ozone (O3), and nitrogen dioxide (NO2). Each index design was examined using four years of air pollution data from GEOS-CF in over 800 cities worldwide to determine which design most effectively predicted respiratory outcomes.
This study provides the first health-based air quality index reflecting children’s respiratory risk that can be used in cities around the world. The team’s analysis suggests that an index adjusted for extreme pollution values and controlling for co-pollutants most effectively communicates respiratory risk from air pollution on a global scale. This design uses simple calculations based on daily concentrations of three major pollutants – PM2.5, O3, and NO2 – and the index can be used by environmental agencies throughout the world to provide local air quality alerts, using either regional observations or publicly available model forecasts such as NASA’s GEOS-CF.
Calculating global daily index values for communicating children’s respiratory risk using GEOS-CF air pollution estimates. Image credit: NASA/NYU.
In the future, as more global health data is acquired, this and other air quality indices can be evaluated and improved to best reflect local health risks to the public. Ideally, any air quality index would be further validated using local health data to confirm associations with local, population-level health risks. NYU researchers are currently working alongside agencies across the world to quantify city-specific risk values and provide local agencies with the tools and skills needed to implement air quality communications within their own communities.
Evaluating the potential impact of this study, Gladson observed, “NASA products like GEOS-CF are making it increasingly possible to study and communicate the impacts of air pollution in regions where people breathe the worst air and yet have no resources to measure it. Alongside GEOS-CF, this index can be used in areas without air quality monitoring to alert parents to the health risks their children face during times of elevated outdoor air pollution.”
Gladson continued, “I am hopeful for a future where parents anywhere in the world can access information that could save their child from experiencing an asthma episode, a trip to the emergency room, and, ultimately, developing chronic conditions that can impact their long-term development and wellbeing.”
Related Links
- Gladson, L.A., K.R. Cromar, M. Ghazipura, K.E. Knowland, C.A. Keller, B.N. Duncan, 2021, Communicating Respiratory Health Risk Among Children Using a Global Air Quality Index. Environ. International, 159, doi:10.1016/j.envint.2021.107023.
- Keller, C.A., K.E. Knowland, B.N. Duncan, J. Liu, D.C. Anderson, S. Das, R.A. Lucchesi, E.W. Lundgren, J.M. Nicely, E. Nielsen, L.E. Ott, E. Saunders, S.A. Strode, P.A. Wales, D.J. Jacob, S. Pawson, 2021: Description of the NASA GEOS Composition Forecast Modeling System GEOS-CF v1.0. J. Adv. Model. Earth Sy., 13, doi:10.1029/2020MS002413.
- World Health Organization, 10 July 2018, Air Pollution and Child Health: Prescribing Clean Air. WHO/CED/PHE/18.01.
Sean Keefe, NASA Goddard Space Flight Center
