Einsatz des Biolumineszenz-Hemmtests zur Untersuchung kontaminierter Böden

The luminescence inhibition test was applied to contaminated soils. Two different methods were used: The standard sediment elutriate test and the so-called “solid-phase test”. Cadmium sulfate, p-cresol and o-nitroanisole were used as model substances for the contamination of two different soils that show significant differences in grain size. While five of six elutriates acted toxically in the standard elutriate test, the solid-phase test detected only the heavy metal clearly. The interpretation of the solid-phase test results, unlike those of the standard sediment test, is problematic because of the high and varied ground inhibitions of the uncontaminated soils. This suggests that the rate of adsorption of the bacteria depends on the type of soil. An interpretation without an uncontaminated reference seems impossible. A good correlation between the portion of elutriated contaminants and the values of inhibition was only obtained by using the standard elutriate test.     

Umbilical cord haematoma as a complication of intrauterine intravascular blood transfusion

Between October 1985 and February 1989, 49 ultrasound-guided intravascular fetal blood transfusions were performed in 16 patients (14 with rhesus (Rh) isoimmunization, 2 with non-immunologic hydrops fetalis (NIHF)). As an intra-operative complication, perivascular haematoma of the cord occurred in three patients (7 per cent). In two cases, fetal bradycardia necessitated delivery by Caesarean section at 30 and 32 weeks' gestation, respectively. In the third case, fetal bradycardia developed during transfusion, at 31 weeks' gestation, but normalized within 3 min. The baby was delivered as planned at 36 weeks of gestation, after another transfusion at 34 weeks. Dislodgement of the needle tip into perivascular tissue, caused by sudden fetal or maternal movements, is the reason for this complication. The haematoma develops as a result of delayed recognition and continuous transfusion into Wharton' s jelly. Cord haematoma may be diagnosed in time by continuous ultrasound imaging, as illustrated in case 3. To minimize the risk of needle dislodgement during transfusion, sedation of the mother and complete immobilization of the fetus by injecting a short-acting muscle relaxant into the umbilical vessel are recommended.     

Development and validation of a method for determination of trace levels of alkylphenols and bisphenol A in atmospheric samples

A method has been developed and validated in order to assess the occurrence of the alkylphenols tert-octylphenol and the isomers of technical nonylphenol as well as bisphenol A in gasphase and aerosol samples of a remote area. Gasphase samples were adsorbed to XAD2 resin, aerosol samples were taken on glass fiber filters. After ultrasonic extraction, clean-up by column chromatography and silylation of the analytes, ten nonylphenol peaks were quantified separately using a GC-MSD-SIM method. The absolute limits of detection and determination are in the range of a few pg per compound, which is a prerequisite for the quantification of the analytes in relatively unpolluted air. The precision of the whole analytical method is in the range of 1-17% and the recoveries range from 57% to 80%. Problems were encountered during method development due to the tendency of the analytes to sorb to glass surfaces. Silanisation of glassware was crucial to achieve acceptable recoveries. The widespread use of the analytes in plastic resins resulted in sample contamination. For this reason a careful choice of sampling material was necessary. Measured concentrations in gasphase samples (lower nanogram per m3 range) and aerosol samples (upper picogram per m3 range) are one to three orders of magnitude below already published concentrations.     

Clearance of atrazine in soil describing xenobiotic behavior

The primary aim of this study was to evaluate the “clearance concept” as a tool for describing the behavior of xenobiotic movement into and through soils. As an example, degradation of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) with the formation of metabolites 2-chloro-6-isopropylamino-s-triazine (desethylatrazine) and 2-chloro-4-ethylamino-s-triazine (desisopropylatrazine) was investigated. Atrazine was sprayed post-emergently in doses of 0.125 or 0.5 g active ingredient/m² each on four test plots. Soil type was a sandy-loam, on which corn (Zea mays L.) was cultivated. Soil samples were taken as cores of 0.2 m depth 0, 1, 2, 4, 8, 12, 16 and 20 weeks after application of atrazine, and analyzed by HPLC. Soil concentrations of atrazine were highly correlated (r=0.993, p< 0.001) between the two applications of 0.125 g/m² and 0.5 g/m². Up to 50% of the atrazine was measured as metabolites during the whole vegetation period. Clearance of atrazine from soil was calculated as the total load of atrazine divided by the area under the soil atrazine concentration time curve. Soil atrazine clearance was calculated as 5.13 +/? SD 1.10 and 5.17 +/? SD 1.02 liter of soil per day for doses of 0.125 g/m² and 0.5 g/m², respectively (from a “soil unit” of 1 × 1 × 0.2 meter). The clearance concept might be a tool for risk assessment of xenobiotics.     

Fate and exposure models in relation to risk assessment

The recognition of potential long-term effects of substances, has led to the development of regulations and legislation which emphasis the need for assessing the risks posed by both new and existing substances for man and the environment. The evaluation of fate and exposure models is put into perspective in relation to the developments over the last five years in the framework of the EU regulations and national legislation within the European Community. The validation of environmental exposure models (multi-media models) is described in the context of quality assurance of models available to a user group, which is different from the quality assurance aspects for a developers group.     

Transformations of <Emphasis Type="Italic">n</Emphasis>-alkanes from petroleum pollutants in alluvial groundwaters

Investigations presented in this paper were aimed at defining the alterations of n-alkane composition in cases of oil-polluted alluvial sediments. Therefore, oil-polluted groundwater samples, taken in five different time intervals during a period of 28 months, were investigated. Samples of alluvial sediments were taken from two boreholes within an oil refinery at Pancevo, Yugoslavia. In both boreholes significant alterations with characteristic degradation of "oil" n-alkanes with no odd- or even-member predominance were observed, as well as subsequent synthesis of new ones with pronounced even-member predominance, and with maxima at C₁₆ and C₁₈. Since no additional contamination of boreholes was observed by analyses of steranes and triterpanes, the observed changes can only be attributed to microbial activity. It is assumed that for the degradation of oil n-alkanes, as well as for the synthesis of "new" n-alkanes, algae such as dinoflagellates are responsible. This assumption was confirmed by identification of n-alcohols with even-member predominance (C₁₄–C₂₀), by identification of cholesterol, as well as of n-fatty acids with even-member predominance (C₁₄–C₁₈) in the extract with n-alkane even-member predominance. Electronic Publication     

Maternal investment and sex ratio adjustment in American bison calves

Summary Cow-calf behavior was observed in American bison (Bison bison) to determine if mothers invested differentially in sons and daughters. Cows nursed sons significantly longer than they did daughters in their first three months of life. The increased nursing time for sons was not compensated for by increased grazing time by their mothers. Grazing and activity patterns did not differ significantly between sons and daughters. Cows that had sons bred later in the breeding season than nulliparous cows, barren cows, or cows with daughters. Nine yearling sons compared to only two yearling daughters continued to suckle from their mothers for up to 15 months of age. Cows that had sons the previous year were more apt to be barren in the current year than cows that had daughters in the previous year.     

A field test of the Bruce effect in the monogamous prairie vole (Microtus ochrogaster)

The Bruce effect is a widely studied reproductive phenomenon in rodents in which exposure of pregnant females to unknown males causes termination of the current pregnancy. The Bruce effect has been reported from numerous studies in the laboratory, and one field study with the promiscuous gray-tailed vole, Microtus canicaudus, failed to support it. We conducted a field study with the monogamous prairie vole, M. ochrogaster, to determine if complete replacement of the male population every 10-14 days affected pregnancy and juvenile recruitment. The mean days to first parturition for control and treatment females were 36.8 and 44.4 days. Fifty-five percent of control females and 33% of treatment females conceived within the first 14 days of the study. All control females and 79% of treatment females successfully delivered at least one litter. These differences between treatment and control populations provide minimal support for the Bruce effect when compared with results from laboratory studies. Nulliparous females may have experienced some pregnancy disruption, but not parous females. Removal of mates, rather than exposure to strange males, may have contributed more to the lower reproductive success of treatment females than exposure to strange males. Treatment females, however, had lower juvenile recruitment than controls, which may have been due to infanticide from strange males. Our results are more similar to those of the field study of the gray-tailed vole than predicted, based on laboratory studies of prairie voles.     

Influence of ship emissions on air quality and input of contaminants in southern Alaska National Parks and Wilderness Areas during the 2006 tourist season

The impact of ship emissions on air quality in Alaska National Parks and Wilderness Areas was investigated using the Weather Research and Forecasting model inline coupled with chemistry (WRF/Chem). The visibility and deposition of atmospheric contaminants was analyzed for the length of the 2006 tourist season. WRF/Chem reproduced the meteorological situation well. It seems to have captured the temporal behavior of aerosol concentrations when compared with the few data available. Air quality follows certain predetermined patterns associated with local meteorological conditions and ship emissions. Ship emissions have maximum impacts in Prince William Sound where topography and decaying lows trap pollutants. Along sea-lanes and adjacent coastal areas, NO_x, SO₂, O₃, PAN, HNO₃, and PM_2.5 increase up to 650 pptv, 325 pptv, 900 pptv, 18 pptv, 10 pptv, and 100 ng m^?3. Some of these increases are significant (95% confidence). Enhanced particulate matter concentrations from ship emissions reduce visibility up to 30% in Prince William Sound and 5–25% along sea-lanes.