Cleanest and Dirtiest Air in U.S. Revealed The IQAir 8th annual World Air Quality Report, released in 2025, provided a detailed analysis of global air pollution trends, emphasizing the significant impact of wildfires exacerbated by climate change. The report examined data from 9,446 cities across 143 countries, regions, and territories, revealing alarming levels of particulate matter 2.5 (PM2.5) pollution. PM2.5, a type of fine inhalable particle with diameters of 2.5 micrometers or smaller, poses serious health risks when inhaled. The findings highlighted a global decline in cities meeting the World Health Organization’s (WHO) annual average PM2.5 guideline, with only 14% of cities achieving this standard in 2025, compared to 17% in 2024. Wildfires emerged as a critical factor in worsening air quality, particularly in North America and Europe. Canada, which experienced its second-worst wildfire season on record, became the most polluted country in Northern America for the second time in the report’s history. The smoke from these fires significantly elevated PM2.5 levels across the United States, affecting regions such as the Great Lakes states during the summer and the Pacific Northwest in the fall. In the U.S., annual average PM2.5 levels rose to 7.3 micrograms per cubic meter (µg/m³), a stark increase compared to previous years. The report identified El Paso, Texas, as the most polluted major U.S. city in 2025. Historic dust storms, the most severe since the 1930s, triggered a 46% spike in PM2.5 levels, reaching 11.4 µg/m³. The Southeast Los Angeles region, including areas like Cudahy, East Los Angeles, and Huntington Park, was named the most polluted area in the country due to its vulnerability to wildland-urban interface fires.#canada #iqair #world_air_quality_report #wildfires #el_paso_texas