Abstract:
Petroleum refinery wastewater may contain different chemicals including
polycyclic aromatic hydrocarbons (PAHs) some of which are genotoxie. Release
of the refinery wastewater to the aquatic environments may pose a threat to the
aquatic fauna especially fish populations. Biological effects associated with
wastewater can be assessed using biomarkers as early warning signals. The
objective of the present study was to assess biological effects associated with
wastewaters of Petroleum Refinery, Sri Lanka using a selected PAH indicative
biomarker (bile fluorescent PAH metabolite patterns) and a genotoxic biomarker
(erythrocytic micronuclei in the blood) using fish models. The fish species used in
the study were Oreochromis niloticus for controlled laboratory exposure and
Trichogaster pectoralis and Puntius filamentosus, inhabiting water canals located
near the Petroleum refinery (Pattiwila canal and Heiyanthuduwa canal) for
exposure assessments under natural conditions. A less polluted water body was
selected as the control site for field studies (Bathalagoda reservoir). Bile
fluorescence patterns of the fish were assessed using fixed fluorescence and
synchronous fluorescence spectrometry. Erythrocytic nuclear abnormalities in the
blood (micronuclei, binuclei and other nuclear abnormalities) were examined
using cytogenetic tests. The results showed that several PAHs metabolites
(Napthalene-, Phenanthrene-, Fluoranthene-, Chrysene- and Benzo(a)pyrenetype)
accumulate in bile of 0. niloticus as a result of being exposed to the
Petroleum refinery wastewater under laboratory conditions. Bile of T. pectoralis
and P. fjlamentosus collected from the nearby canals also displayed PAH
exposure in comparison to the fish collected from the control site. Erythrocytic
micronuclei in the blood were highly induced in the fish species examined under
laboratory (upto 20 fold) and field conditions (upto 26 folds) in comparison to
the comparable controls. The present study revealed that tested petroleum
refinery wastewater contains micronuclei inducible contaminants including PAHs.
