Milken researchers map pollution rates in urban areas, examine public health effects – The GW Hatchet

GW researchers used geospatial datasets collected between 2005 and 2019 to track global air pollution levels in urban areas and support efforts to reduce emissions, according to a study published this month.

The study, which the Milken Institute School of Public Health conducted in collaboration with researchers from the University of North Carolina at Chapel Hill and Washington University in St. Louis, tracked the concentration of air pollutants across 13,189 urban areas from 2005 to 2019. GW doctoral student and lead author on the study Soo Yeon Kim said the study’s identification of urban air pollution rates on a global scale could help cities develop strategies for reducing toxic emissions based on their individual conditions.

“By offering a comprehensive time series of three major air pollutants (particulate matter, nitrogen dioxide and ozone) at the city level, our findings can help urban planners and policymakers identify priority pollutants and set reduction targets in their own city/country,” Kim said in an email.

Globally, 91 percent of the population in urban areas breathes polluted air, with 4.2 million excess deaths attributed to ambient air pollution annually, according to the World Health Organization. 

The study followed the levels of common air pollutants, like particulate matter, ozone and nitrogen dioxide, which are linked to breathing problems, like wheezing, and are primarily generated by human industrial activity, according to the Centers for Disease Control.

Kim said continued pollutant rates above WHO guidelines — the study recorded the global mean for ozone parts-per-billion as 51.2, 67 percent higher than the WHO guideline of 30.6 ppb — are “underscoring” a continued risk to public health, with ozone rates increasing by 6 percent, particulate matter remaining consistent and nitrogen dioxide decreasing by 1 percent between 2005 to 2019. 

However, countries in South Asia and sub-Saharan Africa had higher levels of pollutant concentration compared to countries in the global north, with India having 66.7 ppb of ozone compared to the global mean of 51.2 ppb in 2019, according to the study.

“While our current work focused on pollution estimates, we are now analyzing the health burdens attributable to these pollutants to better understand their impacts,” Kim said.

Researchers on the study also developed a website, which is currently down, called Urban Air Quality Explorers, that tracks the concentration of pollutants globally. Kim said he has “hope” policymakers and the public will use the website to make “data-driven” decisions on environmental policy.

“Our high-level summaries can serve as a foundation for future region-specific studies and help advance the field of global environmental health,” Kim said.

Gaige Kerr, an assistant research professor at Milken and a researcher on the study, said the decisions informed by the study could include regulations on industries that produce emissions, like the transportation industry. 

“If we find that an air pollutant related to fossil fuel combustion, like nitrogen dioxide, is going up, that might tell us based on our knowledge of where nitrogen dioxide comes from, then we need to have more strict engine standards on our cars and trucks because the transportation industry and the transportation sector is a major source of nitrogen dioxide,” Kerr said.

Kerr said the study was able to use geospatial data, information that describes features on the surface of the earth, to find urban air pollution levels in regions that have historically not received the necessary technological investment to track air pollution, like the global south. Kerr said this data could enable a better understanding of air pollution globally and particularly how it affects populations in countries that have been overlooked in environmental research because of the scale of the datasets. 

“Datasets like the ones we used in this study actually allow us to understand pollution levels and greenhouse gas emissions in areas that are chronically under-monitored and disinvested in one major novelty of the study,” Kerr said.

Researchers used historical datasets collected from GIS, a computer system that contains, analyzes and displays geographical information, to observe the rate of emissions over time. To measure pollutant concentrations, researchers used pollutant datasets captured via satellite remote sensing. 

Jing Li, an associate professor of geography and the environment at the University of Denver, said using GIS for the study provided an “advantage” compared to other measures of air pollution — like ground-based monitoring stations — which have historically faced high costs and limited reach, because it enabled researchers to better analyze the relationship between environmental hazards and demographics by providing a global perspective to the data.

“GIS can leverage that kind of a spatial principle to make predictions compared to the traditional mathematical way to look at air quality,” Li said. 

Li also said being able to adjust GIS to analyze air pollution at the local and global level makes it more efficient compared to other methods of measuring air quality.

“We can use data, we can use special principles, and we can deliver results in a much more efficient way to look at air quality issues,” Li said.

_{Images are for reference only.Images and contents gathered automatic from google or 3rd party sources.All rights on the images and contents are with their legal original owners.}