Primary and secondary particulates as pollutants. A literature review

摘要: This article discusses primary and secondary particulates with respect to their size distribution, origin, chemical composition. Primary are particles that injected directly into the atmosphere. Usually sizes within range 1 20 jum. Common sources windblown soil, industrial emissions, combustion systems. Examples of typical soot, pollen, fly ash, dust. Secondary relatively small; is 0.01 1.0 nm. They can be generally classified as sulfates, nitrates, or hydrocarbons. formed a result atmospheric reactions involving gaseous species such SO2, NO*, O2, NH3, H2O, The proposed mechanisms for number these outlined relative importance discussed. impact both on health esthetics also