What we breathe affects every part of our health — from our lungs and hearts to our brains and unborn children. In this episode of "What is Public Health", in celebration of National Public Health Week, April 7-13, 2025, we have a special series called "How we built healthier communities ".

On Day 4, we explore the history and impact of clean air laws in the United States, from smog-filled cities and industrial disasters to today’s fight against air pollution and environmental injustice.

We dive into how public health advocacy led to the Clean Air Act, why pollutants like sulfur dioxide, nitrogen dioxide, and particulate matter are so dangerous, and how clean air protections continue to save lives every single day.

We also talk about how air pollution worsens asthma and allergies, what COVID-19 taught us about airborne risks, and what’s at stake if we lose sight of environmental regulation.

Key Takeaways:

• The Clean Air Act, passed in 1970 and amended in 1990, is one of the most effective public health laws in U.S. history.

• Exposure to air pollutants like sulfur dioxide, nitrogen dioxide, and PM2.5 is linked to asthma, heart disease, stroke, and cognitive decline.

• COVID-19 revealed how small airborne particles — including viruses and pollution — can spread in ways that make N95 masks especially effective.

• Children, older adults, and communities of color are disproportionately affected by poor air quality.

• Clean air is not just about comfort or visibility — it’s about long-term survival and health equity.

Resources and Links:
AirNow (check your local air quality index):
https://www.airnow.gov

EPA Clean Air Act Overview:
https://www.epa.gov/clean-air-act-overview

American Lung Association – State of the Air Report:
https://www.lung.org/research/sota

CDC – Asthma and Air Pollution:
https://www.cdc.gov/asthma/air_pollution.html

Union of Concerned Scientists – Environmental Justice and Air Quality:
https://www.ucsusa.org/resources/environmental-justice-and-air-pollution