How are particulate matters and black carbon related?

  • Particle emissions from combustion sources, including fossil fuels, biofuels, and biomass, are broadly referred to as particulate matter (PM).
  • They are usually classified into two types based on their sizes (diameter): PM2.5 and PM10. PM2.5 has diameter less than 2.5 micrometer, while PM10 has diameter less than 10 micrometer and includes PM2.5.
  • Black carbon, as well as secondary sulfate and nitrate particles formed from SOx or NOx precursors, is the major constituent of PM2.5.
  • It represents the solid fraction of PM2.5 that strongly absorbs light energy and converts it to heat, with a resultant effect of causing temperature change, melting of snow and ice (when deposited on snow or ice), and change in precipitation patterns.
  • Furthermore, because of its small size, PM2.5, which includes black carbon, easily penetrates human cells and blood and therefore has high negative impact on human health.