Core Viewpoint - The article discusses a recent study published in Nature that highlights the significant differences in toxicity among PM 2.5 emissions from various sources, suggesting that air quality policies should consider these differences for more effective health benefits [2][4][6]. Group 1: Research Findings - The study combines field measurements with air quality models to assess the toxicity differences of PM 2.5 from various anthropogenic sources [4]. - It was found that PM 2.5 from solid fuel combustion in residential stoves has the highest toxicity, followed by emissions from metallurgy, brake wear, diesel vehicles, gasoline vehicles, cement industry, and power plants [4][5]. - From 2005 to 2021, both the mass emissions of PM 2.5 and the toxicity-adjusted emissions have significantly decreased, with industrial sources contributing 57.5% to the mass reduction, while residential burning accounted for approximately 80% of the toxicity-adjusted reduction [5]. Group 2: Policy Implications - The study suggests that clean air policies should take into account the varying toxicity of PM 2.5 from different sources when formulating emission control regulations [6]. - A framework based on cellular toxicity for PM 2.5 reduction is proposed, which could address specific health risks in different regions, although further epidemiological research is needed to confirm its relevance to human health outcomes and public policy applications [7].