2021–2025年巴西主要城市PM2.5年均浓度变化(μg/m³)
change represents a year-over-year reduction of 33%. The improvement was driven largely by declines in annual average PM2.5 concentrations across several key cities, including Sao Paulo, Sao José dos Campos, Sao Jose do Rio Preto, Campinas, Manaus, and Guarulhos. This downward trend was reflected nationwide, with over 80% of cities meeting the data reporting threshold reporting decreases in annual average concentrations. Additionall, lower monthly average PM2.5 levels in August and September suggest a milder wildfire season compared to the previous year. Many cities recorded monthly average concentrations below 5 μg/m3, while the highest monthly values were only slightly above 25 μg/m3. Notably, no emissions and the long-range transport of particulate matter. In urban areas, particularly in the Southeast, pollution is exacerbated by an aging vehicle flet, inconsistent enforcement of emission standards, and concentrated industrial activity.8 While the 2025 wildfire season was less severe than the record-breaking destruction seen in early 2024, smoke from the Amazon and Pantanal still caused major disruptions. Notably, in September 2025, these fires resulted in Sao Paulo being ranked as the world's most polluted major city for five environmental protections.9 Although he vetoed 63 provisions to maintain strict licensing for major projects and safeguard Indigenous territories, the remaining law—labeled the "Devastation Bil" by critics-drastically streamlines the approval process.91 By collapsing iil un 'sooid aens, oi as auis e oui aouanbs uisulds-aui e Annual hours spent at different PM2.5 pollution levels threats to the Amazon and Atlantic Forest. Despite these risks to public health and climate goals, the President declined activists' call for a fullveto.9293