A new study published in the journal BMC Medicine suggests that air pollution may reduce the positive impact and health benefits of exercise.
Researchers analyzed data from 1.5 million adults in the US, the UK, Denmark, and China, tracking them for more than 10 years. While people who exercised at least 2.5 hours per week had a 30% lower risk of death, that reduction fell to between 12-15% for those who worked out in polluted areas.
According to the World Health Organization (WHO), 99% of the global population breathes unclean air, with air pollution causing seven million premature deaths a year. Indeed, air pollution remains a prevalent health crisis around the world.
Using average PM2.5 levels, the Air Quality Index (AQI) project put together the 2024 ranking of the 25 cities with the worst air pollution in the world. As a general guide, air quality with a PM2.5 (μg/m3) of between 0-12.0 is considered good; 12.1-35.4 is moderate; 35.5-55.5 is unhealthy for sensitive groups; 55.6-150.4 is unhealthy; PM2.5 150.5-250.4 is very unhealthy; and 250.5 or greater is hazardous.
Are you holding your breath? Click through and discover the world’s most polluted cities.