Polychlorinated biphenyls (PCBs) in fish from the Sana River (Bosnia and Herzegovina): A preliminary study on the health risk in sport fishermen

Fish is the main single source of polychlorinated biphenyls (PCBs) exposure in men. Anecdotal reports suggest high wild fish consumption rates among sport fishermen in Sanski Most area, Bosnia and Herzegovina (BiH). Presence of PCBs in the environment in BiH was previously documented. The main objective of this work was to estimate the magnitude of PCBs exposure and assess the potential health risk in sport fishermen in Sanski Most. The fishing pattern and magnitude of fish consumption were estimated in the questionnaire survey conducted during April 2012 among members (n = 60) of the local sport fishermen association in Sanski Most. Calculated median and high-end (90th percentile) fish consumption rates were 31 g d^?1 and 126 g d^?1, respectively. The PCB concentrations (as Aroclor 1254 equivalents), determined by ELISA immunoassay in 28 fish fillets ranged from undetectable to 208 μg kg^?1. Two different exposure scenarios were used: (a) median exposure, calculated from the median fish consumption rate and median PCB concentrations, and (b) “worst case” scenario, calculated from the high-end fish consumption rate and mean PCB concentrations. The results suggest negligible lifelong cancer and non-cancer risks in case of low to moderate fish consumption rate, but possibly unacceptable risk levels in high-end consumers.     

The Brown Trout Population at Loch Fleet Eight Years After Liming

Abstract

At the start of the Loch Fleet Project in 1984, the Loch and the upper 7 km of its efferent stream were found to be devoid of trout (Salmo trutta) as a result of acidification. Following the liming treatments applied to the catchment, from 1986 the formerly toxic water quality conditions (pH ～ 4.5, calcium ～ 1 mgl^?1, elevated aluminium and heavy metal levels) were eliminated, and trout were reintroduced on two occasions, in 1987 and 1988. A total of 520 fish were stocked, at a combined density equivalent to 5.5 kg ha^?1. Surveys of the loch and stream populations were carried out annually until 1993 to monitor their development, using a range of techniques, including electrofishing, gill-netting, seine-netting, spawner trapping and mark-release recapture methods. Length and scale- analysis were used to investigate fish growth.

The trout population in Loch Fleet expanded rapidly as a result of natural spawning in the loch's main feeder stream, augmented by the use of an artificial spawning bed which was constructed at the loch outlet in 1990. in mid-1983 the stock density, estimated by mark-recapture census methods, had increased to 24.9 kg ha^?1. Poor recruitment in the years 1991–93, however, reduced the rate of expansion and resulted in a population comprising mainly older individuals. the poor recruitment in these years was not fully explained but was not caused by water quality and was most likely a result of fry washout by spring spates.

Fish growth rates were high initially and were estimated on the basis of the Elliott trout growth model to be optimal for the prevailing water temperature regime of the loch. By 1991, growth rates had fallen, probably as a result of competition for food, but showed signs of recovery towards the end of the study period in 1993, following the period of lower population densities of young fish.

Trout rapidly repopulated the loch's outlet stream after 1987 but have remained sparse and have shown no signs of spawning within most of the stream. Water analyses have shown that the liming of the Loch Fleet catchment has minimal impact on downstream waters when flows are high, so that potentially toxic acid episodes have not been prevented.     

Pre-and Post-Liming Aquatic Communities and Trout Diets

In the period following liming and before the introduction of brown trout to Loch Fleet, there was a reduction in the numbers of invertebrates, including the Chironomidae, Oligochaeta and Hydracarina in the loch, but an overall increase in invertebrates in the inlet and outlet streams. This was followed in the loch by a recovery in the numbers of certain groups (particularly the Trichoptera and Ephemeroptera) to pre-liming levels in spite of the introduction of the trout.

The diets of the trout comprised a wide variety of aquatic and terrestrial organisms ranging in size from Fprotozoans to newts and are dominated by chironomids. Opportunistic type of feeding as found in the present study appears to be typical of the brown trout and is reported for many water bodies by other workers.

Significant differences (P < 0.05 and P < 0.001) were found in the numbers and weights of certain food organisms in the stomachs of brown trout caught by different fishing methods in the summers of 1992 and 1993. Fish caught by gill net contained fewer planktonic crustaceans and chironomids, but greater numbers of trichopterans and terrestrial organisms, than in those caught by fly and spinner. the differences are probably related to differences in the depth at which the fish, caught by the various methods, were feeding.     

十溴联苯醚(BDE209)在虹鳟体内的羟基代谢产物及其对甲状腺激素水平影响的初步研究

十溴联苯醚(Decabromodiphenyl ether,BDE209)被认为是可疑甲状腺素(TH)干扰物,但干扰机制目前尚不清楚.采用单次腹腔注射的暴露方式,考察了在28d的实验周期内,不同浓度组的十溴联苯醚在虹鳟(Oncorhynchus mykiss)体内的羟基化代谢产物浓度与甲状腺激素(T3和T4)水平.结果表明:十溴联苯醚在虹鳟的肝脏和血液中均可代谢为低溴代羟基多溴联苯醚,且羟基代谢产物在整个实验周期中浓度不断累积;与此同时,血浆中T3和T4浓度均出现下降趋势.进一步的统计分析结果表明,羟基代谢产物与T3和T4浓度水平分别呈显著的负线性相关关系,这说明血浆中的甲状腺激素水平下降可能是由羟基化产物所引起的.     

Toward Adaptive Management: The Impacts of Different Management Strategies on Fish Stocks and Fisheries in a Large Regulated Lake

We applied the adaptive management approach to analyze the demand and feasibility of adaptive management of fish stocks in a large regulated lake, Oulujärvi, in northern Finland. The process consisted of four phases: (1) analysis of the current state of the fisheries system (fishers, related markets and industry, fisheries researches and authorities, related organizations, etc.); (2) analysis of the objectives of different stakeholders; (3) the composition of alternative management strategies and assessment of their impacts; and (4) recommendations for future management. We used catch statistics from the period 1973–1995 to analyze fish stocks and fishing. Fish species involved were brown trout (Salmo trutta L.), whitefish [Coregonus lavaretus (L.) sl.], vendace (Coregonus albula L.); and pikeperch (Stizostedion lucioperca L.). Questionnaires and interviews were applied to ascertain the opinions of different groups of fishermen. Several models and cost–benefit analysis were used to assess the ecological, economic, and social impacts of three alternative management strategies. The results emphasize that when determining stocking levels and fishing regulations, the system should be considered as a whole, and impacts on major fish species and different groups of fishermen should be assessed. The stocking policy and fishing regulations should also be flexible to accommodate changing biotic and societal conditions. The key questions in applying the adaptive management process in Oulujärvi fisheries are how to determine clear objectives for fisheries management, find a fisheries management structure that provides workable interactions between different stakeholders, and arrange cost-effective monitoring. The lessons learned from the Oulujärvi experience and recommendations for fisheries management are relevant to other lakes with conflicting objectives of different stakeholders.     

Spawning behaviour and sex hormone levels in adult and precocious brown trout (Salmo trutta L.) males and the effect of anosmia

Summary. In the present experiment the behaviour and endocrine status of males of the brown trout, Salmo trutta L., (Salmoniformes: Salmonidae) were studied when males were kept in a stream tank with a nest digging female. Groups of mature adult males and precocious intact or anosmic male parr were placed with the nesting female so that the group resembled a natural spawning situation with big anadromous fish acting as dominant males and precocious parr acting as “sneakers”. A control experiment was also run with only males without a female present. In intact parr there were significant positive correlations between the per cent of the total observation time spent with a female, milt volume, and plasma concentration of 17α, 20β-dihydroxy-4-pregnen-3-one. Anosmic parr had significantly lower volumes of strippable milt and gonadal steroid hormone levels compared with intact parr. However, no differences were found in the control experiment. Significantly fewer anosmic parr attended and courted the nesting female and those anosmic fish that attended the female had significantly lower plasma levels of gonadal hormones. Intact parr also displayed a greater number of agonistic acts against other parr without any difference in fighting ability. No differences in aggression occured in the control experiment. In adult males together with a female, post-experimental gonadal steroid hormone levels were higher than pre-experimental levels. Positive correlations between aggression and androgen hormone levels were observed in adult males. No differences in plasma hormone levels were observed between adult males and intact precocious males. The results show that olfactory occlusion results in low steroid hormone levels and milt volumes in precocious males placed in a spawning situation. The courting behaviour was also affected by anosmia. Odours from the nesting female may have caused the enhanced plasma hormone levels and stimulated the males to attend the female. Received 15 May 1997; accepted 29 June 1997.     

应用BLM模型预测我国主要河流中Cu的生物毒性

应用BLM模型对我国5条主要河流15个国控断面中铜的生物毒性进行预测,同时以虹鳟鱼为实验动物进行了实际水样的加标实验,得到实测生物毒性结果.结果表明,珠江、长江、淮河、松花江12个点位BLM模型预测LC50为0.13～0.46mg·L-1,利用虹鳟鱼进行的生物毒性测试结果为0.11～0.47mg·L-1,二者具有较好的一致性.对于黄河流域的3个点位,预测结果为0.42～1.00mg·L-1,实测结果为0.21～0.33mg·L-1,二者差距较大.根据预测结果与测试结果得到的水效应比(WER)范围分别为3.3～11.8与3.3～11.5(黄河流域,WERs值范围分别为10.5～25.0与5.3～8.3),均大于1.该研究提示,中国主要河流水系由于水化学条件不同,即使在相同的总Cu浓度下,所表现的毒性亦有很大差别;利用BLM模型和河流主要水质参数,则可以预测Cu的毒性.根据BLM模型获得的Cu的WERs值,将是制订中国流域水质标准的重要依据.     

Trade-offs between elimination and detoxification in rainbow trout and common bivalve molluscs exposed to metal stressors

The purpose of this paper was to examine trade-offs between elimination and detoxification in rainbow trout and three common bivalve molluscs (clam, oyster, and scallop) exposed to cadmium (Cd), copper (Cu), and zinc (Zn) based on recent reported experimental data. We incorporated metal influx threshold with subcellular partitioning to estimate rate constants of detoxification (k_d) and elimination (k₂). We found that the relationships between k₂ and k_d were negative for rainbow trout and positive for bivalve molluscs. However, the relationships between k_d and % metal in metabolically detoxified pool were found positive for rainbow trout and negative for bivalve molluscs. Our results also indicated that rainbow trout had higher accumulation (∼60-90%) in metabolically active pool when exposed to essential metals of Cu and Zn and had only 10-50% accumulation in response to non-essential metal of Cd. Based on a cluster analysis, this study indicated that similarity of physiological regulations among study species was found between Cd and Zn. Our study suggested that detoxification can be predicted by an elimination-detoxification scheme with the known elimination rate constant. We concluded that quantification of trade-offs between subcellular partitioning and detoxification provides valuable insights into the ecotoxicology of aquatic organisms and enhances our understanding of the subcellular biology of trace metals.     

Fate of ah receptor agonists during biological treatment of an industrial sludge containing explosives and pharmaceutical residues

GOAL, SCOPE AND BACKGROUND: Sweden is meeting prohibition for deposition of organic waste from 2005. Since 1 million tons of sludge is produced every year in Sweden and the capacity for incineration does not fill the demands, other methods of sludge management have to be introduced to a higher degree. Two biological treatment alternatives are anaerobic digestion and composting. Different oxygen concentrations result in different microbial degradation pathways and, consequently, in a different quality of the digestion or composting residue, It is therefore necessary to study sludge treatment during different oxygen regimes in order to follow both degradation of compounds and change in toxicity. In this study, an industrial sludge containing explosives and pharmaceutical residues was treated with anaerobic digestion or composting, and the change in toxicity was studied. Nitroaromatic compounds, which are the main ingredients of both pharmaceutical and explosives, are well known to cause cytotoxicity and genotoxicity. However, little data are available concerning sludge with nitroaromatics and any associated dioxin-like activity. Therefore, we studied the sludge before and after the treatments in order to detect any changes in levels of Ah receptor (AhR) agonists using two bioassays for dioxin-like compounds. METHODS: An industrial sludge was treated with anaerobic digestion or composting in small reactors in a semi-continuous manner. The same volume as the feeding volume was taken out daily and stored at -20 degrees C. Sample preparation for the bioassays was done by extraction using organic solvents, followed by clean up with silica gel or sulphuric acid, yielding two fractions. The fractions were dissolved in DMSO and tested in the bioassays. The dioxin-like activity was measured using the DR-CALUX assay with transfected H4IIE rat hepatoma pGudluc cells and an EROD induction assay with RTL-W1 rainbow trout liver cells. RESULTS AND DISCUSSION: The bioassays showed that the sludge contained AhR agonists at levels of TCDD equivalents (TEQs) higher than other sludge types in Sweden. In addition, the TEQ values for the acid resistant fractions increased considerably after anaerobic digestion, resulting in an apparent formation of acid resistant TEQs in the anaerobic reactors. Similar results have been reported from studies of fermented household waste. There was a large difference in effects between the two bioassays, with higher TEQ levels in the RTL-W1 EROD assay than in the DR-CALUX assay. This is possibly due to a more rapid metabolism in rat hepatocytes than in trout hepatocytes or to differences in sensitivities for the AhR agonists in the sludge. It was also demonstrated by GC/FID analysis that the sludge contained high concentrations of nitroaromatics. It is suggested that nitroaromatic metabolites, such as aromatic amines and nitroanilines, are possible candidates for the observed bioassay effects. It was also found that the AhR agonists in the sludge samples were volatile. CONCLUSIONS: The sludge contained fairly high concentrations of volatile AhR agonists. The increase of acid resistant AhR agonist after anaerobic digestion warrants further investigations of the chemical and toxic properties of these compounds and of the mechanisms behind this observation. RECOMMENDATION AND OUTLOOK: This study has pointed out the benefits of using different types of mechanism-specific bioassays when evaluating the change in toxicity by sludge treatment, in which measurement of dioxin-like activity can be a valuable tool. In order to study the recalcitrant properties of the compounds in the sludge using the DR-CALUX assay, the exposure time can be varied between 6 and 24 hours. The properties of the acid-resistant AhR agonists formed in the anaerobic treatment have to be investigated in order to choose the most appropriate method for sludge management.     

Endocrine disruption of water and sediment extracts in a non-radioactive dot blot/RNAse protection-assay using isolated hepatocytes of rainbow trout

Goal, Scope and Background In order to evaluate the estrogenic activity of sediments and XAD water extracts of selected sites of the catchment area of the River Neckar, a river system in Southern Germany, an integrative assessment approach was used to assess the ecological hazard potential of endocrine-disrupting compounds in sediment and water. Methods The approach is based on estrogen receptor-mediated vitellogenin synthesis induced in isolated hepatocytes of rainbow trout and quantified in a non-radioactive dot blot/RNAse protection-assay in parallel to comprehensive chemical analyses of estrogenic substances. Results and Discussion Numerous investigated extracts revealed an estrogen activity comparable to that of the positive control (1 nM 17?-estradiol corresponding to 270 ng/L in the test medium). Based on a concentration factor of 30 in the extracts and a recovery of XAD resins of approximately 80 %, 17?-estradiol equivalent concentrations between 20 and 26.7 ng/L could be calculated downstream of a sewage treatment plant (< 0.1 ng/L for a reference site). A comparison of the bioassay-derived Bio-TEQs (toxicity equivalents) and the Chem-TEQs revealed a high correlation with a Pearson coefficient of 0.85, indicating that the same ranking of the samples could be obtained with respect to the endocrine disrupting potential with both chemical and bioanalytical analysis. However, the TEQ concentrations computed from chemical analyses were significantly lower than the bioassay-derived TEQ concentrations. In fact, in none of the samples, more than 14 % of the vitellogenin-inducing potency could be attributed to the substances (steroids, alkylphenols, bisphenol A, diethylstilbestrol) analyzed. A comparison of the endocrine disrupting potential of sediments extracted by the solvents acetone and methanol revealed lower biological effects for acetone-extracted samples. Possible reasons may be a masking of endocrine effects in acetone extracts by cytotoxicity, a low extraction efficiency of the solvent acetone, or anti-estrogen potencies of some extracted sediment compounds. Using a mass balance approach, the contribution of the compounds analyzed chemically (Chem-TEQs) to the total endocrine activity (Bio-TEQs) was calculated. Based on the very low detection limits, particularly of the steroids with their high TEF factors, results revealed that a calculation of the Chem-TEQs is associated with considerable scale inaccuracy: Whereas only 7-15 % of the biological effectiveness (Bio-TEQs) could be explained by endocrine substances identified above the detection limits, the assumption of concentrations slightly below the given detection limits would result in a significant over estimation (137-197 %) of the Bio-TEQs. Even the interassay variation of the dot blot assay with different fish donors for primary hepatocyte (factor 2 - 2.5) is relatively low, when compared to the large range of the Chem-TEQ concentrations (factor 20) obtained when applying different modes of calculation. Conclusions and Outlook Overall, only a minor portion of the endocrine activity detected by bioassays could be linked to compounds identified by chemical analysis. In vitro assays for assessment of endocrine activities are useful as sensitive integrating methods that provide quantitative estimates of the total activity of particular receptor-mediated responses. Although discrepancies may also result from different bioanalytical approaches, it is overall likely that bioanalytical and not chemical analytical approaches give the correct estimate of endocrine disrupting potencies in environmental samples. As a conclusion, assessment of endocrine disruption based on chemical analysis alone does not appear sufficient and further research into the spectrum of substances with potential endocrine activity as well as into additive or even synergistic effects in complex environmental samples is urgently needed.