Physiological And Ecological Effects Of Benzo[a]pyrene In Tilapia (Oreochromis Niloticus X O. Aureus)

Persistent Organic Pollutants are a series of high toxic, persistent, and bioaccumulated organic pollutants, which have a serious impact on both human health and the circumstance. It is more and more notable that they put the earth and all human being in danger because of their effect: making biology come across cancer, being abnormality, and being aberrance. The 'Stockholm Convention on Persistent Organic Pollutants (POPs)' gave a list of 12 kinds of important POPs to be forbidden. However, as a news kind of POPs, PAHs is not in the list.Of the wide range of organic contaminants in the environment, polycyclic aromatic hydrocarbons (PAHs) are of concern because of several of them show a high carcinogenic and mutagenic activity, and Benzo[a]pyrene (BaP) was one of the most well known PAHs due to its carcinogenic properties. PAHs is persistent, universal, and of huge harm like other POPs, and also, it keeps inpouring into the environment faster and faster, as the expansion of population and the development of industry. Thus, PAHs is a news host focus, and become more and more accounted of by scientists from all countrys.Tilapia is a kind of fish that can live both in fresh water and salty water. Farther more, it is of high adaptability, wide range of food, fast growing, strong resistibility to illness and coldness, which is saying that tilpia is a very kind of biomarker to be used in experiences.This study evaluated the effect of BaP on antioxidant defense system and histopathological changes in the liver of juvenile hybrid tilapis (Oreochromis Niloticus X O. Aureus). Specifically, we exposed juvenile hybrid tilapis to BaP of 7 different doses (0.1, 0.5, 1.0, 5.0, 10, 50μg/dm~3) for various time periods(6h, 12h, 24h, 36 h, 3d and 7d), and them measured the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroidase (GPX) and observed the histopathological changes in the liver.The results showed that the activities of SOD decreased initially after a short period (several hours) of BaP exposure, and increased at day 3, but decreased at day 7. The same trend was observed for CAT, but CAT responded faster, and at lower dosage, thus more sensitive than SOD. However, both SOD and CAT could be used as sensitive biomarkers for BaP toxicity studies. GPX activity varied among tested dosages and different time periods, and a distinct response to BaP treatment was delayed to day 7 in some high treated concentrations, thus it was not...