Primary Particulate Matter Emission Spectrum (IMAGE) Science China Press Caption Relative contributions of major sources to annual emissions of (A) PM>10, (B) PM2.5–10, (C) PM2.5, (D) BC, and (E) OC from 1960 to 2019. In addition to these listed explicitly, all other sources are summed up as others. Credit ©Science China Press Usage Restrictions Use with credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.