158 research outputs found
Brominated Flame Retardants in the Environment: their Sources and Effects (A Review)
Brominated flame retardants (BFRs) are organic substances frequently used in many industries. The most important group within BFRs are polybrominated diphenyl ethers (PBDEs). Because they persist in the environment, accumulate in food chains and have toxic effects, they are a potential health risk both for animals and humans. Polybrominated diphenyl ethers may disrupt processes of hormonal regulation in living organisms by reducing thyroxine concentrations in the plasma of the exposed individuals. In vitro studies have demonstrated the ability of these substances to bind to estrogen and androgen receptors. Tests on rodents have also demonstrated neurotoxicity of some of the PBDEs. Although industrial use of PBDEs is now regulated to a large extent, PBDEs have already been detected in areas with no apparent industrial load, e.g. in Greenland. This article presents an overview of BFRs-related issues with a particular emphasis on PBDEs, describes toxic effects of those substances and their metabolism in living organisms, and discusses issues related to the incidence of PBDEs in the environment
Stress Response to Long Distance Transportation of Common Carp (Cyprinus carpio L.)
The stress responses and changes in biochemical and haematological indices were investigated in three-year-old common carp (Cyprinus carpio L.) during a long-distance transportation in special truck tanks. Twelve-hour transportation caused a significant increase in ammonia (p < 0.01), mean corpuscular volume MCV (p < 0.01), metamyelocytes ( p < 0.05) and band neutrophils (p < 0.01), and a significant decrease in Cl- (p < 0.05), lactate (p < 0.05), ALT (p < 0.05) and ALP (p < 0.01) levels. The values of LDH (p < 0.01), AST (p < 0.05), CK (p < 0.01) and haematocrit PCV (p < 0.05) were also significantly influenced by the transportation, but no time-dependent relation was found. On the contrary, the levels of cortisol, glucose and total protein in the biochemical profile, and the values of erythrocyte count (RBC), haemoglobin (Hb), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), leukocyte counts (WBC) and leukogram (except for metamyelocytes and band neutrophils) in the haematological profile were not significantly influenced by the transportation. Results showed that pre-transport fish manipulation (hauling, netting, handling, loading) was found to be an important stressor for fish. Long-distance transportation itself was relatively considerate for the common carp tested
Distribution of Metals in Tissues of the Common Carp (Cyprinus carpio L.)
The aim of the present study was to investigate the distribution of selected metals (As, Cd,Pb, Hg, Cr, Cu and Zn) in tissues of the common carp (Cyprinus carpio L.) grown in ponds. A total of 125 market-ready carp (aged 3 - 4 years, weight 2312 ± 583 g) from 10 fishponds in the Czech republic were analysed. The tissues analysed included muscle, liver, kidney, spleen, gills, ovaria and testes. Metal concentrations were determined by the AAS, mercury was determined using a cold-vapour AAS analyse (AMA 254). Results showed different affinities of metals to different tissues. The highest concentrations of As and Hg were in muscle tissue, Cu in the liver, and Cd and Zn in the kidneys, compared with levels in other tissues (p p p p < 0.01) were found in the ovaria compared with the testes. The study showed that meat and gonads of pond carp in the Czech republic are safe from the point of view of contamination with the metals investigated
Effects of Metazachlor on Vitellogenin Induction in Zebrafish (Danio rerio)
The influence of metazachlor on vitellogenesis in juvenile (20 days old) zebrafish (Danio rerio) was investigated after ambient water exposure to concentrations of 0.1, 1.0 and 5.0 mg l-1 of the chloroacetanilide herbicide Butisan 400 SC containing approximately 35.6% (w/w) metazachlor. After 20 days of exposure, vitellogenin concentrations in whole-body homogenates of the fish were measured by direct sandwich ELISA. The results were compared to vitellogenin concentrations in fish from both negative (no exposure) and positive (exposed to natural oestrogen 17β-oestradiol) control groups. Exposure to Butisan 400 SC at a concentration of 5.0 mg l-1 induced vitellogenin synthesis significantly compared to the control fish (p < 0.05). The oestrogenic effect of 17β-oestradiol was confirmed
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