In this episode, we dive into a groundbreaking BMJ study of nearly 60 million U.S. Medicare beneficiaries, revealing how long-term exposure to fine particulate matter (PM₂.₅) increases hospital admission risks for heart diseases—even at low levels. Discover how chronic PM₂.₅ exposure raises rates of ischemic heart disease, stroke, heart failure, arrhythmia, and aneurysms, with no safe threshold, as risks emerge even from 5 μg/m³—well below many current regulatory levels

Learn about the study’s innovative use of causal frameworks and exposure calibration techniques that sharpen our understanding of air pollution’s true impact. We also unpack how the World Health Organization's guideline of ≤ 5 μg/m³ can deliver substantial cardiovascular benefits—yet many U.S. standards may still fall short

Plus, hear how factors like age, education level, neighborhood deprivation, and access to healthcare amplify vulnerability to PM₂.₅—underscoring environmental justice implications