Unprecedented air quality crisis: The impact of widespread fires on air pollution in São Paulo

In 2024, Brazil faced an unprecedented environmental crisis as widespread fires impacted vast regions of the country, with severe effects reaching São Paulo, the largest metropolis in Latin America. This brief communication presents data on the sharp rise in air pollutant concentrations during the crisis and the observed health outcomes among residents. PM₁₀ levels increased by 140.81%, PM_2.5 by 144.26%, nitrogen dioxide (NO₂) by 48.07%, and ozone (O₃) by 24.97% compared to the same period in 2023. These spikes in pollution were associated with a 3.5% increase in the risk of cardiorespiratory problems, as well as a rise in healthcare visits and hospital admissions for respiratory conditions. This severe episode underscores a recurring reality in Brazil. The observed impact highlights the consequences of inadequate wildfire management and insufficient enforcement against illegal burning practices, which persistently threaten public health and environmental stability. We emphasize the urgent need for regulatory updates, improved fire management strategies, and robust public health policies to prevent and mitigate the health impacts of these recurrent pollution crises.