AI Summary
5 min readThis Is Your Brain on Pollution (Update)
It's worse than cigarette smoking, worse than wars, worse than auto accidents. That's how University of Chicago economist Michael Greenstone describes the toll of air pollution on human health. The World Health Organization estimates that roughly seven million people die every year from exposure to fine particles in polluted air—more than double the number who died globally from COVID in 2020, and more than five times the annual death toll from car crashes. But a growing body of research suggests the damage doesn't stop there. Pollution may also be quietly impairing our cognitive abilities, even at levels most Americans consider normal.
The Cognitive Cost of Breathing
Andrea Linose, an environmental economist at Deakin University in Australia, wanted to know whether day-to-day changes in air pollution affect how well adults think. She and her research partner, Boston College economist Edson Severnini, found an unusual data source: Lumosity, the brain-game app with more than 100 million users. They analyzed over four million gameplay observations across the United States, matching each session to local pollution data.
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What you'll learn
- 1 (03:06) **The Shocking Claim** - Michael Greenstone states that air pollution is worse for human health than cigarette smoking, wars, and auto accidents.
- 2 (05:30) **Setting Up the Investigation** - Economist Andrea Linose introduces the problem of particulate matter (PM2.5) and the puzzle of measuring its cognitive effects.
- 3 (07:15) **The Global Scale of the Problem** - Michael Greenstone explains the Air Quality Life Index and how pollution reduces life expectancy across the planet.
- 4 (10:24) **Historical Pollution and the Peppered Moth** - Stefan Hiblic describes how 19th-century coal smoke in England created lasting neighborhood sorting, using the peppered moth as an indicator.
- 5 (15:10) **The Snowball Effect of Pollution** - Hiblic explains how initial pollution-driven sorting became cemented over time, leading to lower test scores and higher crime in historically polluted areas.
- 6 (21:00) **The Lumosity Data Breakthrough** - Andrea Linose describes how she used Lumosity brain-game data from over 4 million gameplay observations to test cognitive effects on adults.
- 7 (24:13) **The Cognitive Impact on Working-Age Adults** - Linose and Severnini present their headline results: pollution impairs cognition, especially memory, for people under 50.
+ Full timestamped outline available in the app
Show Notes
As the Trump administration rolls back environmental regulations, we revisit a 2022 episode that explored the hidden cost of an invisible threat: air pollution.
- SOURCES:
- Angela Duckworth, psychologist at the University of Pennsylvania.
- Michael Greenstone, economist at the University of Chicago, director of the Energy Policy Institute, co-director of the Climate Impact Lab.
- Stephan Heblich, economist at the University of Toronto.
- Andrea La Nauze, economist at Deakin University.
- Steve Levitt, professor emeritus of economics at the University of Chicago.
- Edson Severnini, economist at Boston College.
- RESOURCES:
- "Most Polluted Cities," (American Lung Association, 2026).
- "Air Pollution and Adult Cognition: Evidence from Brain Training," by Andrea La Nauze and Edson Severnini (Journal of the Association of Environmental and Resource Economists, 2025).
- "Air Pollution and Student Performance in the U.S.," by Michael Gilraine and Angela Zheng (NBER Working Papers, 2022).
- "Billions of people still breathe unhealthy air: new WHO data," (World Health Organization, 2022).
- "Evolution of the Clean Air Act," by the United States Environmental Protection Agency (2020).
- "The Death of U.K. Coal in Five Charts," by Hannah Ritchie (Our World in Data, 2019).
- "The Colour of Pollution," (The Economist, 2014).
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