A warning for countries with air pollution problems

Air pollution is far from the most decisive factor for dementia risk, Krauchanka said. About 70% of risk stems from an individual’s genetic predisposition to the disease, and the remainder comes down to age, and lifestyle and environmental factors. Still, all else being equal, PM 2.5 pollution clearly substantially elevates risk, and that conclusion should be a concern for countries where it remains elevated, she said. Although the total global concentration of PM 2.5 has fallen dramatically in recent decades because of more rigorous clean air regulations in countries in the global north, half of the world’s population lives in countries where PM 2.5 is rising. South Asia is especially at risk: Bangladesh, Pakistan, and India rank highest in the world. In all three, median age and life expectancy are rising, meaning that a dementia boom is likely around the corner (in sub-Saharan Africa, where PM 2.5 is also high, life expectancy remains in the low 60s, below the age at which most people develop dementia regardless of environmental factors, Krauchanka said).

That’s not only a tragedy for the individuals and families who are affected—it’s also a major drag on the economy. Alzheimer’s is the third most-costly condition in the US after cancer and heart disease, setting the country back $355 billion every year in costs related to skilled nursing care, home healthcare, hospice care, in addition to less easily measured costs from informal caregiving.

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.