Impact of chronic cadmium exposure at environmental dose on escape behaviour in sea bass (Dicentrarchus labrax L.; Teleostei, Moronidae)

The effect of chronic exposure to a low concentration (0.5 microg l(-1)) of cadmium ions was investigated on escape behaviour of sea bass, Dicentrarchus labrax, using video analysis. Observations were also performed on the microanatomy of lateral system neuromasts. When fish were exposed for 4h per day over 8 days to the cadmium ions, most of both types of neuromasts observed remained intact. However, some of them presented damaged sensory maculae. Whereas before cadmium exposure, fish responded positively to nearly all the lateral system stimulations, after exposure they decreased by about 10% their positive responses to stimulations. From the 15th day after the beginning of cadmium exposure, neuromasts presented progressively less damage, cadmium accumulation in gills and scales decreased significantly and fish escape behaviour had recovered. This study presents a new concept in ecotoxicology: using behavioural change to reveal the effects of pollution levels, scarcely detectable by currently used techniques (physiological responses).     

Polycyclic aromatic hydrocarbons and their hydroxylated metabolites in fish bile and sediments from coastal waters of Colombia

Sediments and fish bile collected from the Atlantic coastal waters of Colombia were analyzed for 16 parent polycyclic aromatic hydrocarbons (PAHs), and 23 hydroxylated PAHs (OH-PAHs), respectively. Sediments contained overall mean SigmaPAH concentrations of 2090, 234 and 170 ng/g, dry wt, for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The mean concentration of the summed OH-PAHs in fish bile was 1250, 180 and 64.1 ng/g bile wt for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The results suggest that Cartagena Bay is heavily polluted by PAHs, and that exposure to high concentrations of PAHs together with other factors could contribute to the decreased health of fish living in this ecosystem. This is one of the first studies to describe the analysis of 23 individual OH-PAHs in fish bile, using authentic standards.     

Tissue distribution of organochlorine pesticides in fish collected from the Pearl River Delta, China: implications for fishery input source and bioaccumulation

Fish tissues from different fishery types (freshwater farmed, seawater farmed and seawater wild) were analyzed for organochlorine pesticides (OCPs), with the aim to further our understanding of bioaccumulation, and reflect the state of different fishery environments. Significantly higher SigmaOCP levels were found in seawater farmed fish than others, and among three freshwater farmed species, the lowest levels occurred in filter-feeding fish (bighead carp). Liver contained the highest SigmaOCP levels, while no significant differences were found among other tissues. Among DDT components, p,p'-DDT was abundant in seawater fish, while for freshwater fish, p,p'-DDE was the predominant congeners, except for northern snakehead (34% for p,p'-DDE and 30% for p,p'-DDT). The new source of DDTs to freshwater fish ponds was partly attributed to dicofol, whereas sewage discharged from the Pearl River Delta and anti-fouling paint were likely the DDTs sources to seawater farmed fish.     

Transfer of Sr into fish in Finnish lakes

The long-term behavior of ⁹⁰Sr was investigated from 1987 to 1997 in fifteen lakes in southern and central Finland following the 1986 Chernobyl accident. Both water and fish samples (perch, pike, vendace) were analyzed. ⁹⁰Sr stays long in the freshwater ecosystem; the observed half-lives during the study period were generally around 10 years in water and even longer in fish. One lake exhibited very different behavior for ⁹⁰Sr, with elevated levels in fish and water and very short observed half-life in fish, less than 2 years. Concentration factors of ⁹⁰Sr in fish (Bqkg⁻¹ f.w. in fish/Bqkg⁻¹ in water) among the studied lakes significantly correlated with both the Ca concentration and electrical conductivity of the water. More ⁹⁰Sr was transferred into fish in lakes with a low electrical conductivity and a low Ca concentration. Among other water parameters evaluated were pH, color, total nitrogen, and phosphorus.     

Suitability of a magnetic particle immunoassay for the analysis of PBDEs in Hawaiian euryhaline fish and crabs in comparison with gas chromatography/electron capture detection-ion trap mass spectrometry

A gas chromatograph/electron capture detector-ion trap mass spectrometer (GC/ECD-ITMS) was used for the determination of polybrominated diphenyl ethers (PBDEs) in euryhaline fish and crabs. GC/ECD-ITMS results showed that average recoveries from the spiked fish samples are in a range of 58-123% with relative standard deviations (RSDs) of 5-19%. PBDE concentrations obtained from GC/ECD-ITMS ranged from 28 ng/g to 1845 ng/g lipid weight (lw) in all aquatic species collected from Hawaiian brackish waters. The general BDE congener concentration profile observed in this study is BDE-47 > BDE-100 > BDE-154 > BDE-99 > BDE-153 > BDE-28 > BDE-183. The ELISA results expressed as BDE-47 equivalents correlated well with those of GC/ECD-ITMS, with a correlation coefficient (R² = 0.68) and regression coefficient (slope = 0.82). Comparison of ELISA with GC/ECD-ITMS results demonstrated that ELISA provides a timely and cost-effective method to screen PBDEs in fish and crab samples.     

Correlations between dioxin-like and indicators PCBs: Potential consequences for environmental studies involving fish or sediment

Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish. We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future.     

Fish products available in Polish market – Assessment of the nutritive value and human exposure to dioxins and other contaminants

Chemical analyses were performed on one hundred and twenty of the most popular varieties of fish products (smoked fish, salted fish, and marinated fish) of the fish market in Poland. The contents of the nutritive substances of fish products (protein, micro- and macronutrients, vitamins A₁, D₃, E, and fatty acids) and the chosen contaminant (toxic metals – mercury, cadmium, lead, arsenic; dioxin/furans – PCDDFs; dioxin-like PCB – dl-PCBs; seven congeners of polybrominated diphenyl ethers – PBDEs; organochlorine pesticides – ΣDDT, HCB, ΣHCH and marker polychlorinated biphenyls – PCB₇) levels were determined. It was confirmed that fish products are a good source of digestible proteins, iodine, selenium, and vitamin D₃. The fundamental nutritive benefit of processed fish lies in its highly beneficial fatty acid composition, which is what imparts them healthy nutritive qualities. The high content of long-chain polyunsaturated fatty acids (LC-PUFAs), which is not noted in other food products, is particularly important.The majority of contaminants studied were present in low levels. The possible threats, particularly in the case of pregnant/nursing women and young children, can pose the levels of dioxin/furans (PCDD/Fs) and dioxin-like (dl-PCBs) in smoked Baltic salmon and smoked sprat, elevated in a relation to particular requirements concerning the content of sum of PCDD/Fs and dl-PCBs in fish (8 pg WHO-TEQ g⁻¹).The health benefits and risks stemming from consumption of fish products were determined according to the Provisional Tolerable Weekly Intake (PTWI) for chosen contaminants (Cd, Hg, As, PCDD/Fs + dl-PCB) and the quantity of ingredients that render a fish diet healthy based on data from the EFSA Journal [EFSA (European Food Safety Authority), 2005. Opinion of the scientific panel on contaminants in the food chain on a request from the European Parliament related to the safety assessment of wild and farmed fish. EFSA J. 236, 1–118]. In regard of high content of LC-PUFAa and other nutritive ingredients, fish products available in Polish market may be considered as healthy food.However, many authors point at contaminants (methylmercury, PCDD/Fs) occurring in fish and fish products as on potential health problem, and emphasize that the amount of that hazardous substances should be limited in human diet.     

Bioaccumulation and trophic transfer of dioxins in marine copepods and fish

Despite the great concerns about dioxins in the marine environments, the biokinetics and bioaccumulation of these compounds in marine organisms remains little known. Using radioactive tracers the aqueous uptake, dietary assimilation efficiency, and elimination of dioxins were measured in marine phytoplankton, copepods and seabream. The calculated uptake rate constant of dioxins decreased with increasing trophic levels, whereas the dietary assimilation efficiency (AE) was 28.5-57.6% in the copepods and 36.6-70.2% in the fish. The dietary AE was highly dependent on the food concentrations and food type. The elimination rate constant of dioxin in the copepods varied with different exposure pathways as well as food concentration and food type. Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish. Aqueous uptake can be an important pathway only when the bioconcentration of dioxins in the phytoplankton was low.     

Concentration of DL-PCBs in fish from market of Parma city (north Italy): estimated human intake

The concentrations of 12 congeners of non-ortho and mono-ortho dioxin-like polychlorinated biphenyls (ΣDL-PCB) were measured in 30 fish samples from Parma markets by GC/MS technique. The samples were randomly purchased, choosing the species commonly found in supermarkets. The concentration of DL-PCBs estimated remained under the fixed Italian limit of 4 pg g⁻¹ ww WHO-TEQ (World Health Organization-Toxic Equivalent) in the major part of the samples, so the situation seems to be not at a level sufficient to pose a risk to human health of the Parma population. The medium daily intake for DL-PCBs for Italian consumers (Parma) was also estimated. This value generally resulted minor than 2 pg g⁻¹ ww WHO-TEQ kg⁻¹ body weight, exceeding only in four cases: eel, smooth hound, starry smooth hound and tuna.     

Effects of N-acetyl-L-cysteine on fish hepatoma cells treated with mercury chloride and ionizing radiation

Organisms are exposed to natural radiations from cosmic or terrestrial origins. Furthermore the combined action of radiation with various chemicals is an inevitable feature of modern life. Radiation is known to cause cell death, mainly due to its ability to produce reactive oxygen species in cells. N-acetyl-l-cysteine (NAC) is a well-known sulfhydryl-containing antioxidant whose role in radioprotection has been reported. Synergistic effects of radiation and mercury chloride on human cells was previously reported by the authors. Based on the previous report, this study was designed to assess the synergistic effects of radiation and mercury chloride on fish hepatoma cells, as well as to investigate the protective effects of NAC on the cells. The cytotoxicity of radiation was enhanced in the presence of mercury chloride. NAC in lower concentrations prevented cells from death after irradiation with lower doses (<300 Gy) while it did not prevent cells from radiation-induced death after irradiation with higher doses (300, 500 Gy). The intracellular glutathione (GSH) levels significantly decreased after irradiation while the combined treatment of NAC and radiation alleviated the decrease in the GSH levels. The investigations give a clue for the action mechanism of synergistic or protective effects of NAC on the cells. Due to their high resistance to ionizing radiation, the PLHC-1 cells can be effectively used as a screening tool for assessing the combined effects of radiation with toxic chemicals.