Contaminated runoff from roads, including tunnel wash water is an important source of pollution to the aquatic environment. To minimise the impact from direct release of runoff waters, mitigating actions such as sedimentation ponds have been installed in areas with dense vehicle traffic. These ponds often have established ecosystems. The purpose of this study was to investigate a) if the fish from the ponds showed reduced condition or if biomarkers indicated effects of run-off; b) the transfer of PAHs from runoff material to organisms could explain the effects observed.
Levels of CYP1A enzyme and DNA single strand breaks were higher in fish from a sedimentation pond than from the nearby river. The condition index of the fish from both the sedimentation pond and the river were significantly reduced compared to levels found fish from a pristine lake unaffected by traffic. Also PAH-metabolites in the bile of fish from the sedimentation pond and the nearby river were two orders of magnitude higher than fish living in the pristine lake. The results indicate that the fish were affected by the run-off from traffic, and were in accordance with previous results indicating a relationship between contaminants related to traffic and responses in fish.
The results will be discussed in light of the isomer composition of the PAHs in different aquatic matrices from the ponds (water, sediment, plants and organisms) as means for source apportionment of the PAHs.
urban run-off, traffic, effects in fish, PAH source apportionment