Secondary aerosol lines

Sea spray, volcanic eruptions, soil dust, as well as some industries (cement manufacturing) produce the so called primary aerosols, i.e. the material is emitted directly in particulate state (Klockow, 1982), and they are both line and coarse. Secondary aerosols are produced in the atmosphere usually by eondensation after emission from high temperature sources, and they are fine as a rule. Considering the difference in the chemical composition it is recognized that the major components of the fine aerosols are toxie substances of anthropogenic origin such as As, Cd, Pb, Se, Zn etc. while the course aerosols are enriched in elements like Ca, Fe, Si coming from erosion, sea aerosols and other natural sources. 

FIGURE 14.9 Measured OC concentrations (solid line) and estimated secondary organic aerosol concentrations (shaded area) during July 2001 in Pittsburgh, Pennsylvania (Cabada et al. 2004). 

Physical containment of biohazards is achieved through the use of primary and secondary barriers. Primary barriers, the first line of defense against the release of a biohazardous agent, are the measures used to contain the experimental material, and include both techniques and equipment. In the context of this chapter, however, they refer to the use of items of equipment, particularly safety cabinets. Primary barriers are used to provide physical separation of the worker and experimental materials to prevent injury to the worker, provide physical separation of the experimental work from the environment to prevent contamination of the work, and control the release of aerosols created by the work which could pose a hazard for the researcher. 

Reinnig, M.C., J. Warnke, and T. Hoffmann (2009), Identification of organic hydroperoxides and hydroperoxy acids in secondary organic aerosol formed during the ozonolysis of different monoterpenes and sesquiterpenes by on-line analysis using atmospheric pressure chemical ionization ion trap mass spectrometry. Rapid Comm. Mass Spec., 23, 1735-1741. 

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