These Are The Most-Polluted Countries In The World Almost the entire global population breathes air that exceeds the air quality limits set by the World Health Organization (WHO). In this graphic, Visual Capitalist's Marcus Lu maps the world’s most polluted countries according to IQAir, ranked by their annual average PM2.5 concentration (μg/m³) in 2023. The unit μg/m³ refers to micrograms per cubic meter. What is PM2.5? PM2.5 refers to fine particulate matter, with a diameter... Read this story
