carbon particles from burning oil-based fuels and biomass, particularly in developing countries, are not only a health-hazard but may also contribute to global warming.
The toxicity of carbon particles ("particulate") has been stressed in the designation of PM10 and PM2.5, which refers to particles of size of 10 and 2.5 microns (thousandths of a millimetre) or less. The smallest of these particles are breathed into the deep lung, and duri