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

transition phase between slurried sediments and soils, as well as set more
realistic guidelines for cleanup. Beyond the previously described differences,
state regulations and standards vary based on the intended beneficial use
(beach nourishment, compost/topsoil, final cover at a landfill or superfund site,
residential or industrial uses, or aggregate/fill) of a given dredge sediment.
In the states of the Great Lakes Commission (Illinois, Indiana, Michigan,
Minnesota, New York, Ohio, Pennsylvania and Wisconsin), there is also a
regional framework of guidelines and standards to aide in the proper
management and beneficial use of dredged sediments (GLC, 2004). Currently,
dredge sediments are considered a waste product rather than a resource (GLC,
2004). One of the goals of the Great Lakes Commission (GLC) is to combine
knowledge from existing case studies, policy, guidance, and regulations to utilize
dredge sediments as a resource, especially in upland placement settings.
Risk Assessment
Contaminants, including PAHs, are assessed for risk based on their toxicity and
exposure. Low molecular weight PAHs are considered directly toxic (Sims and
Overcash, 1983) and HMW PAH compounds are considered genotoxic, or
capable of causing damage to DNA (Lijinsky, 1991). Toxicity is mainly the result
of PAH metabolic transformations in the human body into a complex mix of
quinones, quinines, cis- and trans-dihydrodiols, phenols, epoxides and other
oxidized metabolites depending on the hydrocarbon and the metabolic route
(Harvey, 1997; Dabestani and Ivanov, 1999; Volkering and Breure, 2003). Some
of these reactive metabolic intermediates can covalently bind to nucleic acids to
induce strand breaks and DNA damage, leading to mutation and tumor initiation
(Harvey, 1997). The carcinogenic and mutagenic potential of PAHs depends on
their metabolites.
Humans can be exposed to both directly toxic and genotoxic compounds through
ingestion, inhalation, and dermal exposure (i.e. drinking contaminated water,
consumption of plants or animals that have come in contact with the
contaminant, breathing PAH particulates, or holding PAH contaminated soil in
your hand). Once humans come in contact with the PAH compound, it is
distributed, metabolized, stored in the human body or excreted. Once in the
human body, the PAHs can impact the respiratory, reproductive, and
neurological systems, cause birth defects, and cancer (Figure 13).
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