The effects of organic environmental chemicals on the growth of the alga Scenedesmus subspicatus: A contribution to environmental biology

The effective concentrations of 15 chemicals, inhibiting the cell growth of the alga $\text{Scenedesmus subspicatus}$ by 10 % and 50 % during 96 hours, have been investigated in a static test under controlled laboratory conditions.     

Synthetische Nitromoschus-Duftstoffe und Bromocyclen Neue Umweltchemikalien in Fischen und Muscheln bzw. Muttermilch und Humanfett

Es wird über Kontaminationen mit synthetischen benzoiden Nitromoschus-Verbindungen Moschus Xylol, Moschus Keton, Moschus Ambrette, Moschus Mosken in verschiedenen Fischarten aus Binnengew?ssern und Forellen aus Aquakulturen, Muscheln, Muttermilch und Humanfett berichtet. Bromocyclen wurde in Sü?wasserfischen — besonders Forellen aus dem Ausland — gefunden. Die Nitromoschus-Verbindungen werden in gro?en Mengen unter anderem als Duftstoffe in Waschmitteln, Seifen, Cremes und Lotions verwendet. Es wird über ?kotoxikologische Wirkungen (Fischtoxizit?t), den biologischen Abbau und das Biokonzentrationspotential dieser Umweltchemikalien in Fischen berichtet. Neben der oralen Aufnahme über die Nahrung mu? beim Menschen die Hautresorption und die inhalative Aufnahme von Nitromoschus-Verbindungen berücksichtigt werden. Um diese Rückst?nde im Menschen und in Lebensmitteln zu reduzieren bzw. zu vermeiden, wird an die Hersteller von Nitromoschus-Verbindungen bzw. an die Riechstoff-, Kosmetik- und Reinigungsmittelindustrie appelliert, aus Vorsorgegründen auf die Herstellung bzw. den Einsatz von Nitromoschus-Verbindungen und Bromocyclen in allen ihren Produkten zu verzichten.     

Levels of dioxins in fish and fishery products on the German market

In 1995-1998 the contents of polychlorinated dibenzodioxins and dibenzofurans of 184 pooled fish samples were analysed. Sampling focused on fish and fishery products with a market share of more than 1% and covered all fishing grounds important for the supply of the German market. Investigation included 15 different fish species, shrimp, mussel and squid samples and various fishery products, typically on the German market. Generally lean fish species like cod, saithe or Alaska pollock were less contaminated on fresh weight basis than fat fish species like herring, Greenland halibut and sardine. In herring the dioxin content is related to the fishing ground. Low concentrations were found in North Sea herring, high concentrations measured in samples from the Baltic Sea. Dioxin contents in fishery products did not differ significantly from the raw fish samples. Results allow an estimation of the daily intake of dioxins and furans via fish consumption in Germany. Based on a daily fish consumption of 20 g the average intake of dioxins via fish is 6.2 pg WHO-PCDD/F-TEQs per person and day.     

Occurrence of bisphenol A in surface water and uptake in fish: evaluation of field measurements

In this study the actual presence of the suspected endocrine disrupter Bisphenol A (BPA) in water systems was studied in the Netherlands. BPA was shown to be present in Dutch surface water at levels up to 330 ng/l, and one occasional observation of 21 microg/l. During the three sampling periods, 60-80% of the samples, most from marine and estuarine locations, contained BPA levels below the limit of quantification (14-40 ng/l). At a selected number of locations the presence of BPA in fish was studied, which showed that BPA varied from 2 to 75 ng/g in the liver and 1 to 11 ng/g in the muscle. Based on present measured concentrations in surface water and on literature derived toxicity data it was concluded that ecotoxicological effects nor estrogenic effects are likely to occur in the field situation.     

A comparative characterization of dissolved organic matter by means of original aqueous samples and isolated humic substances

The aim of our study is to test the use of less time-consuming spectroscopic methods applied on original water samples in order to obtain information about DOM composition without any sample preparation. These results were directly compared with results from a conventional isolation and characterization procedure of dissolved humic substances (fulvic acids – FA) isolated from the same water sample. FAs were characterized by UV-, fluorescence-, FTIR spectroscopy and elemental composition. UV absorbance and fluorescence behavior of FAs and original water samples follow the same pattern. A lower UV absorbance and a lower humification index (derived from the synchronous fluorescence spectra) of about 15% is typical for water samples compared to the FAs. We computed linear relationships between properties of the original water sample (UV-, synchronous fluorescence spectra) and the isolated FA (IR absorption, C/N ratio). The application of synchronous fluorescence and UV spectroscopy of aqueous samples has been proved to result in similar information about DOM composition as the characterization of isolated humic substances concerning the content of aromatic structures and the degree of humification.