CHAMPAIGN, Ill. – Up to 18% of the 5.1 million deaths caused each year by fine particulate air pollution are linked to trade across a wealth gap, in which higher-income countries consume goods and services that cause pollution exposure in much lower-income ones, according to a new study led by researchers at the University of Illinois Urbana-Champaign.
The research, published April 17 in Nature Communications, is the first country-level analysis of how international trade redistributes air-pollution-related deaths among nearly 200 nations. Beyond quantifying health impacts, the study also estimates the associated economic health externalities using multiple valuation methods, capturing these impacts from different perspectives. It further accounts for differences across income groups and levels of economic development, revealing substantial disparities in how trade-related pollution burdens are distributed.
Photo by L. Brian Stauffer
“We find that about 15% of global air-pollution-related mortalities occur across a wealth gap, where consumption in higher-income countries is linked to health impacts in lower-income countries,” said Christopher Tessum, a professor of civil and environmental engineering in The Grainger College of Engineering and the study's senior author.
Modeling the health impacts of air pollution requires tracking how emissions are transported, chemically transformed in the atmosphere, and eventually removed — a process whose effects vary widely by location, source, and emission type. Doing so globally is computationally expensive, which is why earlier studies were limited either to individual countries or to coarse regional groupings.
To address this challenge, Tessum’s team used a reduced-complexity air quality model, InMAP (Intervention Model for Air Pollution), to efficiently simulate pollutant transport, transformation, and removal at the global scale. They then combined these results with Multi-Regional Input-Output (MRIO) economic models to attribute the resulting health impacts to consumption across countries. This integrated framework links emissions to both production and consumption activities while remaining computationally tractable for the 2,500 simulations required. The team also used two independent MRIO databases to ensure that the results are robust to different representations of the global economy.
The work was led by PhD student Shiyuan Wang, with collaborators Sumil Thakrar of the University of Edinburgh and Justin Johnson of the University of Minnesota.
The study finds that the United States is the world's largest net exporter of pollution-related mortality, with consumption by U.S. households, businesses, and government linked to an estimated 166,000 to 175,000 deaths abroad each year. The United Kingdom, France, and Germany are also major net exporters. China, India, Indonesia, and Bangladesh are the largest net importers.
On a per-capita basis, the largest exporters of mortality are small, wealthy economies: the United Arab Emirates, Kuwait, Luxembourg, Hong Kong, and Singapore.
Roughly 1 billion people — primarily in sub-Saharan Africa, Eastern Europe, and South Asia — live in countries where more than half of the air-pollution deaths tied to economic activity are caused by demand from countries with more than double their per-capita GDP.
How these deaths are valued in policy analyses matters, Wang says, because conventional methods can inadvertently reward exporting pollution abroad.
U.S. regulatory agencies typically use a “Value of Statistical Life” (VSL) that counts only damages to U.S. citizens and property — a “Business as Usual” approach that assigns zero value to pollution deaths caused abroad by U.S. consumption. An alternative method recently used in U.S. climate policy does count international deaths but adjusts their value based on the incomes of affected countries. Tessum and colleagues argue that while this is an improvement, it still creates an incentive to locate polluting activity in poorer nations, because deaths there are assigned a smaller dollar value than deaths at home.
“We find that a common way of assigning economic value to environmental damages like air pollution actually incentivizes this 'export' of air pollution deaths from richer countries to poorer countries,” Wang said. “We came up with an alternative valuation method, based on the idea of 'fair trade,' that avoids that incentive.”
Under the team's proposed method, an exporter of pollution treats a death abroad as equal in value to a death at home. Applied to the United States, the approach raises the estimated air pollution externality from about 3% of GDP under current accounting to roughly 14% — a figure comparable in scale to total U.S. healthcare spending.
The authors suggest the framework could help lower-income countries negotiate with foreign investors and trading partners for arrangements that better balance economic development with public health, and help decision-makers in wealthier nations avoid directing investment in ways that shift pollution burdens onto poorer countries.
The research was partially supported by the U.S. National Science Foundation (grant CBET 23-39462) until it was terminated in April 2025 and used computing resources at the National Center for Supercomputing Applications at Illinois.
The paper, “International trade and air-quality-related mortality,” is available here.