Environmental Engineering Reference
In-Depth Information
Determination of Polycyclic Aromatic
Hydrocarbons (PAHs) in Surface Waters
and Runoff
Olalekan S. Fatoki, Titus Van Ree, and Joyce Nakhavhembe
Introduction
PAH are ubiquitous environmental pollutants of natural and anthropogenic
origins. Microbial synthesis, synthesis by higher plants and volcanic activities are
major natural source contributions but they contribute a very small amount
compared to anthropogenic sources
[1]
. They are important priority pollutants
emanating anthropogenically from incomplete combustion of organic matter
mainly coal- and oil-burning, plants and vehicle emissions as combustion products.
Polycyclic organic matter that contains benzo [a] pyrene and other PAH contain-
ing materials is released from forest and agricultural fires and they are most likely
absorbed onto smoke particles settling on all kinds of surfaces where they are
transferred by rainfall into aquatic environment.
[2-4]
. PAH are slow to degrade
in the environment, and sediments in particular are “sinks” where chemicals tend
to concentrate
[5, 9]
.
Their mutagenic and carcinogenic nature has been widely recognized by several
researchers
[2, 6, 7]
. They are classified as carcinogenic because they are metabo-
lized to dihydrodiols by hydrocarbon hydroxylase, which is present in the liver and
these dihydrodiols and their epoxide derivatives bind to DNA and proteins and start
mutagenic processes in the cells
[11]
. PAH can enter human beings via inhalation
through lungs when they breathe air which is contaminated by PAHs from cigarette
smoke, wood smoke, coal smoke and smoke from industrial sites
[12, 13]
. PAHs
can also enter the human body through drinking water contaminated with PAHs, or
swallowing food, soil or dust particles containing PAHs. These compounds can also
enter the human body through skin contact. In the body, PAHs are stored in all
