Gullaya Wattayakorn
Department of Marine
Science, Chulalongkorn University
Polycyclic aromatic hydrocarbons (PAHs)
are common environmental contaminants that have been listed as priority pollutants
by the United Nations Environment Programme (UNEP) because of their potential
carcinogenicity, mutagenicity and toxicity to aquatic organisms and humans.
They are commonly found in the environment. The bulk of PAHs comes from incomplete
combustion of organic matter, such as in fuel combustion, coke production,
oil refining, aluminium production and open fires. It is evident that such
sources of PAHs are found widely in the region. In Thailand, PAH molecules
such as naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene,
anthracene, chrysene, perylene and benzo(g,h,i)perylene were identified in various estuarine and
coastal sediment samples. Possible sources of PAHs in the sediments were identified
by Fluoranthene/Pyrene, Phenanthrene/
Anthracene, SMPhe/Phe and (2+3-ring)/(4+5-ring) PAHs ratios. The ratios indicated mixed signature of
petrogenic and pyrogenic origins. There is an increasing trend of PAH contamination
in sediments in the upper part of the Gulf, hence provide a warning sign of
potential risk in the Gulf.