Wild birds of declining European species are dying from a thiamine deficiency syndrome.

Wild birds of several species are dying in large numbers from an idiopathic paralytic disease in the Baltic Sea area. Here, we demonstrate strong relationships between this disease, breeding failure, and thiamine (vitamin B(1)) deficiency in eggs, pulli, and full-grown individuals. Thiamine is essential for vertebrates, and its diphosphorylated form functions as a cofactor for several life sustaining enzymes, whereas the triphosphorylated form is necessary for the functioning of neuronal membranes. Paralyzed individuals were remedied by thiamine treatment. Moreover, thiamine deficiency and detrimental effects on thiamine-dependent enzymes were demonstrated in the yolk, liver, and brain. We propose that the mortality and breeding failure are part of a thiamine deficiency syndrome, which may have contributed significantly to declines in many bird populations during the last decades.

Dredging associated effects: maternally transferred pollutants and DNA adducts in feral fish.

This study reports on the bioavailability, maternal transfer, and genotoxicity in feral fish of organic sediment pollutants. Northern pike (Esox lucius) and perch (Perca fluviatilis) were caught in a polluted bay before and during dredging activities and from reference areas. Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed in ovulating eggs to investigate if the bay sediment posed a threat to early life-stages of fish. On the basis of previous investigations in this area, the level of exposure via maternal transfer and diffusive uptake of water-borne pollutants after hatch is likely sufficient to cause abnormalities in early life-stages of fish. During dredging, hepatic DNA adducts were elevated in adult fish, demonstrating an increased release of genotoxic compounds, which may contribute to adverse effects in aquatic organisms for several years. Although no substantial increase of maternally transferred pollutants were observed during dredging, this is the first time a correlation between hepatic DNA adducts in fish and pollutant burden in their eggs is demonstrated. Our findings underline the importance of combining chemical and toxicological methods as well as a need for greater emphasis on other polycyclic aromatic compounds in environmental risk evaluations.

Basic physiological biomarkers in adult female perch (Perca fluviatilis) in a chronically polluted gradient in the Stockholm recipient (Sweden).

By measuring a battery of basic physiological biomarkers and the concentration of SigmaDDT in adult female perch (Perca fluviatilis), an assumed aquatic pollution gradient was confirmed, with the city of Stockholm (Sweden) as a point source of anthropogenic substances. The investigation included an upstream gradient, westwards through Lake Mälaren (46 km), and a downstream gradient, eastwards through the Stockholm archipelago (84 km). The results indicated a severe pollution situation in central Stockholm, with poor health status of the perch: retarded growth, increased frequency of sexually immature females, low gonadosomatic index, and disturbed visceral fat metabolism. SigmaDDT, measured as a pollution indicator, was 10-28 times higher than the background in perch from the Baltic Proper. Besides the main gradient other sources of pollution also influenced the response pattern of the measured biomarkers. In particular, there were strong indications of pollution coming from the Baltic Sea.

The distribution and relative toxic potential of organic chemicals in a PCB contaminated bay.

For reliable monitoring of environmental improvement, the PCB contaminated bay Orserumsviken on Sweden's Baltic coast was investigated prior to remediation. We examined PCB congener patterns and the relative toxic potential of PCBs in extracts of three matrices: bottom sediment, settling particulate matter and the dissolved phase (obtained from semi-permeable membrane devices). Congener patterns were similar in all matrices. Three fractions were isolated from the extracts: (1) aliphatic and monocyclic aromatic compounds (MAC-fraction), (2) dicyclic aromatic compounds (DAC-fraction), including PCBs, and (3) polycyclic aromatic compounds (PAC-fraction), including PAHs. Total extracts and fractions were injected into newly fertilised rainbow trout eggs. At larval stage, hepatic EROD activities were quantified. Though high, the PCB contamination could explain only an estimated 1-5% of the total EROD induction. The order of EROD induction potential was: total extract > PAC-fraction > DAC-fraction > MAC-fraction in all matrices, suggesting that in Orserumsviken PACs made a larger contribution to the EROD induction potential than PCBs and other DACs.

A bio-effect directed fractionation study for toxicological and chemical characterization of organic compounds in bottom sediment.

The major aim of this study was to characterize toxic organic compounds in bottom sediments from a PCB polluted bay. To overcome difficulties in pinpointing toxicants in complex environmental samples we applied a bio-effect directed (BED) fractionation approach and investigated the relationships between aromaticity, teratogenicity, and aryl hydrocarbon receptor (AhR) mediated toxicity. Hepatic ethoxyresorufin O-deethylase (EROD) activities and malformations were investigated in rainbow trout (Oncorhynchus mykiss) larvae exposed by injecting sediment extract and fractions (separated by their degree of aromaticity) thereof into newly fertilized eggs. Our results imply that non-additive effects get more pronounced the more complex the exposure. The fraction mainly composed of dicyclic aromatic compounds (DACs), including PCBs, was surprisingly less teratogenic than the fraction mainly composed of polycyclic aromatic compounds (PACs). A major part of the latter potential was isolated in a subfraction mainly composed of three- and four-ring compounds (including alkylated and sulphur-heterocyclic compounds). Though no clear relationship between aromaticity and EROD induction was observed, both the DAC- and the PAC-fractions contributed equally to the EROD induction potential. A major part of the PAC-fraction's induction potential came from a subfraction containing compounds with more than five rings. No clear relationship between teratogenicity and EROD induction was observed, underlining the need for a battery of biomarkers in estimating environmental risk. Two specific malformations not previously described in literature-asymmetric yolk sac and fin edema-could be tracked through the fractionation steps, suggesting that this BED-fractionation strategy is a reliable tool for pinpointing toxic compounds in the environment.

Global accounting of PCBs in the continental shelf sediments.

The recycling longevity of hydrophobic organic contaminants (HOCs) within the global environment is set by their permanent removal through processes such as degradation and burial in geological reservoirs. More than 90% of the global sediment burial of organic carbon (OC) occurs on the continental shelves, representing < 10% of the earth's ocean area. The propensity of HOCs to associate with organic matter, and the proximity of most population centers and thus presumed source areas to coastal regions, led us to investigate shelf sediments as a depository of significance for global HOC budgets. Here, the global inventory and burial fluxes of polychlorinated biphenyls (PCBs) in continental shelf sediments were estimated on a congener-specific basis from a database of 4214 distinct continental shelf surface sediment samples. To account for near-urban sampling bias, the locations of each datum relative to nearest population center were classified as Local (< 1 km), Regional (1-10 km), or Remote (> 10 km), according to a comprehensive vector map of the world (Digital Chart of the World) in a GIS environment. The global inventory of, for instance, PCB congener 153 was 1200 ton (95% confidence limit maximum: 2100 ton; and minimum 720 ton). The Remote sub-basin of the North Atlantic contains approximately half of the global shelf sediment inventory for most of the PCB congeners studied. The shelf sediment inventories of individual PCB congeners constitute significant fractions of their recently updated cumulative historical global emissions estimates. The estimated inventory in the shelf corresponds to about 10% of maximum emission estimates for lower-chlorinated congeners. However, for the more bioaccumulable, higher-chlorinated, congeners the shelf reservoirs appear to account for up to 80% of the estimated maximum cumulative global emissions. These shelf inventories represent 1-6% of the global industrial production of PCBs. The global burial fluxes were estimated to be on the order of 8-24 ton/yr each for the eight major congeners investigated, again, with the shelf constituting a more significant removal sink of the more chlorinated congeners. The permanent removal into deeper shelf sediments of PCB153 and PCB180 suggests that the global environmental mean residence times of these pollutants are on the order of 110 and 70 years, respectively. Hence, even after production and direct releases have been halted, we may expect to be exposed to such persistent pollutants for decades and centuries to come.

Serial fine needle cytology in the diagnosis of esophageal cancer.

OBJECTIVE: To describe a method of registering local spread of cancer in the esophageal wall through serial endoscopic fine needle aspiration (FNA), to evaluate FNA as a diagnostic tool as compared to histologic biopsies and brush cytology, and to investigate cytologic appearances of aspirates and correlate them with survival STUDY DESIGN: Fifty-two patients with esophageal cancer were investigated with serial FNA every second centimeter from the upper esophageal sphincter aborally down to the level of macroscopic tumor. Histologic biopsies and brush cytologies were then performed. RESULTS: Of investigated cases, 33% showed malignant or suspect malignant cells from macroscopic tumor, at > or = 4 cm orally, as did 3 of 12 patients at 14 cm. FNA was more sensitive than brush cytology in establishing the diagnosis. A high ratio between the numbers of benign and malignant cells in aspirates from gross tumor tissue correlated with shorter survival (P < .03). CONCLUSION: Serial FNA can demonstrate local microscopic tumor spread in the wall of the esophagus in vivo in esophageal cancer patients. FNA is also a useful adjunct in establishing the diagnosis. Finally, evaluations of tumor cytology may have prognostic value.