particulate matter (PM)

PM is a complex mixture of elemental carbon (EC), particulate organic compounds (POCs), acids, dust, soil, and sulfate and nitrate compounds. In particular, the burning of coal releases particles of silica (SiO₂), alumina (Al₂O₃), and iron oxide (FeO and Fe₂O₃). Oil combustion releases heavy metals that include cadmium, cobalt, copper, nickel, and vanadium.