The Baltic Sea: An ecosystem with multiple stressors.

This introductory chapter to our Environment International VSI does not need an abstract and therefore we just include our recommendations below in order to proceed with the resubmission. Future work should examine waterbirds as food web sentinels of multiple stressors as well as Baltic Sea food web dynamics of hazardous substances and how climate change may modify it. Also, future work should aim at further extending the new frameworks developed within BALTHEALTH for energy and contaminant transfer at the population level (Desforges et al., 2018, Cervin et al., 2020/this issue Silva et al., 2020/this issue) and their long term effects on Baltic Sea top predators, such as harbour porpoises, grey seals ringed seals, and white-tailed eagles. Likewise, the risk evaluation conducted for PCB in connection with mercury on Arctic wildlife (Dietz et al., 2019, not a BONUS BALTHEALTH product) could be planned for Baltic Sea molluscs, fish, bird and marine mammals in the future. Finally, future efforts could include stressors not covered by the BONUS BALTHEALTH project, such as food web fluxes, overexploitation, bycatches, eutrophication and underwater noise.

Comparisons of polybrominated diphenyl ether and hexabromocyclododecane concentrations in dust collected with two sampling methods and matched breast milk samples.

UNLABELLED: Household dust from 19 Swedish homes was collected using two different sampling methods: from the occupant's own home vacuum cleaner after insertion of a new bag and using a researcher-collected method where settled house dust was collected from surfaces above floor level. The samples were analyzed for 16 polybrominated diphenyl ether (PBDE) congeners and total hexabromocyclododecane (HBCD). Significant correlations (r = 0.60-0.65, Spearman r = 0.47-0.54, P < 0.05) were found between matched dust samples collected with the two sampling methods for ∑OctaBDE and ∑DecaBDE but not for ∑PentaBDE or HBCD. Statistically significantly higher concentrations of all PBDE congeners were found in the researcher-collected dust than in the home vacuum cleaner bag dust (VCBD). For HBCD, however, the concentrations were significantly higher in the home VCBD samples. Analysis of the bags themselves indicated no or very low levels of PBDEs and HBCD. This indicates that there may be specific HBCD sources to the floor and/or that it may be present in the vacuum cleaners themselves. The BDE-47 concentrations in matched pairs of VCBD and breast milk samples were significantly correlated (r = 0.514, P = 0.029), indicating that one possible exposure route for this congener may be via dust ingestion. PRACTICAL IMPLICATIONS: The statistically significant correlations found for several individual polybrominated diphenyl ether (PBDE) congeners, ∑OctaBDE and ∑DecaBDE between the two dust sampling methods in this study indicate that the same indoor sources contaminate both types of dust or that common processes govern the distribution of these compounds in the indoor environment. Therefore, either method is adequate for screening ∑OctaBDE and ∑DecaBDE in dust. The high variability seen between dust samples confirms results seen in other studies. For hexabromocyclododecane (HBCD), divergent results in the two dust types indicate differences in contamination sources to the floor than to above-floor surfaces. Thus, it is still unclear which dust sampling method is most relevant for HBCD as well as for ∑PentaBDE in dust and, further, which is most relevant for determining human exposure to PBDEs and HBCD.

Enantiomer-specific accumulation of hexabromocyclododecanes in eggs of predatory birds.

The diastereomeric composition of hexabromocyclododecane (HBCD) in eggs of peregrine falcon (Falco peregrinus), white-tailed sea eagle (Haliaeetus albicilla), guillemot (Uria aalge) and common tern (Sterna hirundo) as well as the guillemots' main prey, herring (Clupea harengus) was determined by reversed-phase chromatography with triple-stage quadrupole mass spectrometric detection (LC-MS-MS). alpha-HBCD was the predominant diastereomer in all bird species, while in herring, gamma-HBCD made a substantial contribution. Two, as yet unidentified diastereomers, were detected in common tern egg. The alpha-, beta- and gamma-HBCD (+) and (-) enantiomers were separated using a chiral stationary phase. The enantiomer fractions for alpha-HBCD differed substantially between different bird species as well as between guillemot and its prey, herring. Total HBCD levels determined by LC-MS-MS were comparable to those previously obtained by GC-MS.

Polybrominated diphenyl ethers (PBDEs) and their methoxylated derivatives in pike from Swedish waters with emphasis on temporal trends, 1967-2000.

Temporal trends of five tetra- to hexabromodiphenyl ethers [BDE47, BDE99, BDE100, BDE153 and BDE154) and two methoxy-tetraBDEs [6-methoxy-2,2',4,4'- tetraBDE (6-MeO-BDE47) and 2'-methoxy-2,3',4,5'- tetraBDE (2'-MeO-BDE68)] in pike from Lake Bolmen for the years 1967-2000, are presented. All BDE congeners show increasing trends up to the mid-1980s (Sigma5PBDE from 60 to 1600 pg/g wet weight in 1989, i.e. a more than 25-fold increase), and then decrease or level off. The decreasing trends of PBDEs after the 1980s were considerably slower in the present study than was found in a study of an environmental matrix from the Baltic Proper covering the same time period. This difference suggests local sources near Lake Bolmen. The MeO-BDEs show initially decreasing concentrations, which for 6-MeO-BDE47 continues until the early 1990s. The concentrations of 6-MeO-BDE47 in herring from five locations along the Swedish coast increased from south to north in the Baltic Sea. No correlation between the concentrations of the BDE congeners and the MeO-BDEs was observed, indicating sources other than PBDEs for these compounds. The presence of MeO-BDEs in fish from lakes with different characteristics suggests a natural production not favoured by eutrophication, or dependent on sampling season and geographical location.

Organochlorine pesticides, polychlorinated biphenyls and dioxins in human milk from Swedish mothers.

Ten human milk samples, collected from two towns, Uppsala and Sundsvall, in Sweden in 1994 were analysed for selected chlorinated pesticides (HCB, alpha- and gamma-HCH, DDT, DDD and DDE) and PCB congeners (PCBs 28, 77, 101, 105, 118, 126, 138, 153, 156, 158, 167, 169 and 180), PCDDs and PCDFs. The levels found in this study, including the toxic equivalent (TEQ) values, showed a slight downward trend between 1986 and 1994 and are somewhat lower than levels reported from other countries. The contribution of both the mono- and non-ortho PCBs, together with that of PCDD/Fs to the total TEQ values was assessed. Over 70% of the TCDD equivalents was derived from PCBs, PCB 126 being the major contributor. Other high PCB contributors were PCBs 156 and 118. The levels of HCB, alpha- and gamma-HCH, and sigma DDT were generally higher in Uppsala than in Sundsvall. They were, however, over 50% lower in 1990 than in 1986 and have since changed little. For the PCDD/Fs the results show a marked decrease (ca 50%) in levels between 1986 and 1994. There is an indication that PCB 153 and PCB 126 may be good indicators for total PCB and TEQ levels respectively.

Cognitive correlates of dental anxiety.

This study examined cognitive correlates of dental anxiety among 24 highly anxious patients and 17 low-anxious patients. In both groups, anxiety expectations, dental trait anxiety, and state anxiety (in the waiting room and in the dental chair) were rated. Negative cognitions and cognitive control were also assessed. It was found that dentally high-anxious patients claimed to experience more negative thoughts than those with low anxiety (p < 0.001). None of the highly anxious patients reported relatively few negative cognitions, and none of the patients in the low-anxiety group reported relatively numerous negative cognitions. While patients from both groups reported that cognitive control declined with the imminence of treatment, highly anxious patients were found to have less control over their negative thoughts (p < 0.001). A series of stepwise regression analyses revealed that both the number of negative cognitions and perceived cognitive control accounted for 75% of the variance in dental trait anxiety. The results of the present study suggest that cognitive activities, such as negative thinking (catastrophizing) and cognitive control, are important moderators of dental anxiety.

Review of behavioural research in dentistry 1987-1992: dental anxiety, dentist-patient relationship, compliance and dental attendance.

A review is presented of the behavioural research in dentistry published in or after 1987 on dental anxiety, dentist-patient relationship, compliance and dental attendance. It is concluded that little progress has been made in the field of behavioural dentistry during those years and recommendations are made to improve future research efforts.

Venom resistance in the hedgehog, Erinaceus europaeus: purification and identification of macroglobulin inhibitors as plasma antihemorrhagic factors.

Hedgehog (Erinaceus europaeus) plasma contains factor(s) which neutralize the hemorrhagic activity of European viper (Vipera berus) venom. These antihemorrhagic factor(s) were purified by gel filtration on Sephacryl S-200 and chromatography on Cibacron Blue Sepharose. The macroglobulin fraction obtained was characterized for proteinase inhibiting activity, molecular weight and purity by polyacrylamide gel electrophoresis and immunological cross-reactivity and was found to contain the three macroglobulin proteinase inhibitors--alpha 2-macroglobulin, alpha 2-beta-macroglobulin and beta-macroglobulin. The purified macroglobulins were totally able to neutralize Vipera berus venom hemorrhagic activity, but no distinction between them in this respect was possible.

Further studies of plasma protease inhibitors in the hedgehog, Erinaceus europaeus; collagenase, papain and plasmin inhibitors.

Hedgehog plasma was separated by gel filtration on Sephacryl S-200, the fractions resolved by electrophoresis and the electrophoretograms characterized for collagenase, papain and plasmin inhibiting activities with the high mol. wt substrate casein. The three inhibitors previously identified as alpha 2-, alpha 2-beta- and beta-macroglobulins were found to inhibit all three proteases. These were the only collagenase inhibitors found in plasma. Hedgehog alpha 2-chymotrypsin inhibitor and beta-protease inhibitor were both found to also inhibit papain. Three new inhibitors specific for papain (gamma-, alpha 2- and alpha 1-cysteine protease inhibitors) and one for plasmin (alpha 2-antiplasmin) were also found, bringing the number of protease inhibitors in hedgehog plasma to 14. Immunological cross-reactivity as studied by immunoelectrophoresis showed homology between hedgehog alpha 2-macroglobulin and rat murinoglobulin I and between hedgehog alpha 2-antithrombin and rat antithrombin III.

Purification and characterization of alpha 2-, alpha 2-beta- and beta-macroglobulin inhibitors in the hedgehog, Erinaceus europaeus: beta-macroglobulin identified as the plasma antihemorrhagic factor.

Three macroglobulin inhibitors were purified from hedgehog (Erinaceus europaeus) plasma by sequential chromatography on Cibacron Blue Sepharose, Sephacryl S-200 and preparative agarose gel electrophoresis. Each macroglobulin was characterized for proteinase inhibiting activity, molecular weight by polyacrylamide gel electrophoresis (PAGE), subunit size by sodium dodecyl sulfate (SDS)-PAGE, immunological cross-reactivity to other macroglobulins and antihemorrhagic activity against European viper (Vipera berus) venom. Hedgehog alpha 2-macroglobulin is a tetramer (Mr 800,000) composed of identical monomers (Mr 200,000) that inhibits all proteinases tested and is the homologue of human alpha 2-macroglobulin, rat alpha 2-acute phase globulin, dog alpha 1-macroglobulin and swine alpha 2-macroglobulin fast. Hedgehog alpha 2-beta-macroglobulin is a dimer (Mr 450-550,000) composed of identical monomers (Mr 200,000) that inhibits all proteinases tested and appears to be structurally similar to other animal 'half-molecule' macroglobulins. Hedgehog beta-macroglobulin (Mr 700,000) gave subunits of 34,000 and 39,000 after SDS-PAGE and showed cross-reactivity with swine alpha 2-macroglobulin slow. It inhibits all proteinases tested and is the only macroglobulin with antihemorrhagic activity against V. berus venom. This antihemorrhagic activity may be due to beta-macroglobulin's different structure as compared to other macroglobulins, which may make it less susceptible to inactivation by venom proteinases.

Circannual changes in blood coagulation factors and the effect of warfarin on the hedgehog Erinaceus europaeus.

Levels of blood coagulation factors were measured monthly in hedgehogs kept at 20 degrees C under a natural-light schedule for 1 yr using prothrombin time and the P & P method. Hedgehogs display a circannual cycle of blood coagulation factors in the absence of temperature cues, with high levels corresponding to the active period and low levels corresponding to the hibernation period. Ten hedgehogs and ten guinea pigs were treated with clinical doses of warfarin and blood coagulation factors measured. Warfarin caused a similar decrease in vitamin K-dependent blood coagulation factors in both species.

Identification and characterization of trypsin, chymotrypsin and elastase inhibitors in the hedgehog, Erinaceus europaeus, and their immunological relationships to those of other mammals (rat, pig and human).

Hedgehog plasma was separated by gel filtration on Sephacryl S-200, the fractions resolved by electrophoresis and the electrophoregrams characterized for trypsin, chymotrypsin and elastase inhibiting activities with both low and high molecular weight substrates. Approximate molecular weights were also determined. At least ten protease inhibitors were characterized in hedgehog plasma including three macroglobulins. The hedgehog protease inhibitors were identified by immunoelectrophoresis. Four protease inhibitors showed homologies with specific human, rat or swine antisera. These were alpha 2- and beta-macroglobulins, alpha 1-protease inhibitor and alpha 2-antithrombin.

Resistance of the prairie vole (Microtus ochrogaster) and the woodrat (Neotoma floridana), in Kansas, to venom of the osage copperhead (Agkistrodon contortrix phaeogaster).

Prairie vole (Microtus ochrogaster) serum has no anti-lysing or antibody activity against Osage copperhead (Agkistrodon contortrix phaeogaster) venom. However, the serum has an anti-hemorrhagic component, which significantly reduces the size of hemorrhage produced by the minimal hemorrhagic dose of venom and which blocks the minimal hemorrhagic dose at a dilution of 1/8. Woodrat (Neotoma floridana) serum also has an antihemorrhagic component which blocks the minimal hemorrhagic dose at a dilution of 1/32. When compared to similar sized rodents previously tested in Texas, the anti-hemorrhagic activity in the serum of the Kansas rodents is similar. This suggests that venom resistance in prey items of venomous snakes may be more common than thought previously.