Remediation of PAH-Contaminated Soils and Sediments: A ...

Vapor pressure
Vapor pressure defines the point at which PAHs in the solid state either
evaporate into a gaseous form or condense back to a solid state. The higher the
vapor pressure (at normal temperatures), the more volatile the compound is.
Naphthalene (11.866 Pa) and is more volatile and would readily evaporate more
rapidly than dibenz[a,h]anthracene (2.80 x 10 −9 Pa) at normal temperatures
(Mackay and Callcott, 1998). Polycyclic aromatic hydrocarbon vapor pressures
are important for determining risk associated with dredge sediments, transfer
between two resources (soil and air) as well as field sampling and lab safety.
Vapor pressures of select PAH are presented in Table 1.
Priority PAH
The U.S. EPA has placed 16 PAH compounds on the Priority Pollutant List
created under the Clean Water Act (Table 1). Pollutants are chosen for this list
because of potential for toxicity and frequency of occurrence in hazardous waste.
Seven of these 16 PAHs are considered to be possible or probable carcinogens
(ATSDR, 1995). Diagrams of molecular structures of these PAHs can be found
in Figure 1.
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