Fipronil and two of its transformation products in water and European eel from the river Elbe.

Fipronil is an insecticide which, based on its mode of action, is intended to be predominantly toxic towards insects. Fipronil bioaccumulates and some of its transformation products were reported to be similar or even more stable in the environment and to show an enhanced toxicity against non-target organisms compared to the parent compound. The current study investigated the occurrence of Fipronil and two of its transformation products, Fipronil-desulfinyl and Fipronil-sulfone, in water as well as muscle and liver samples of eels from the river Elbe (Germany). In water samples total concentrations of FIP, FIP-d and FIP-s ranged between 0.5-1.6ngL(-1) with FIP being the main component in all water samples followed by FIP-s and FIP-d. In contrast, FIP-s was the main component in muscle and liver tissues of eels with concentrations of 4.05±3.73ngg(-1) ww and 19.91±9.96ngg(-1) ww, respectively. Using a physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals, the different distributions of FIP, FIP-d and FIP-s in water and related tissue samples could be attributed to metabolic processes of eels. The measured concentrations in water of all analytes and their fractional distribution did not reflect the assumed seasonal application of FIP and it seems that the water was constantly contaminated with FIP, FIP-d and FIP-s.

Organic pollutants in sediment cores of NE-Germany: comparison of the marine Arkona Basin with freshwater sediments.

During a contamination survey in NE-Germany sediment cores were sampled at 5 locations with freeze-coring devices and conventional box-coring systems. In total more than 40 samples were analysed for several organic compounds (136 PCDD/F, 33 PCB, 39 PAH, 10 DDX, 4 HCH, 4 CB), sedimentological parameters (TOC,TC,TIC,LOI), some total trace metals (Pb,Cd,Cr,Cu,Zn) and dated by measurement of the (210)Pb and (137)Cs activity. The deepest segment of the cores from the Arkona Basin and the freshwater lakes were dated back to the end of the 19th century. A comparison of marine versus freshwater data is presented. The contamination levels of Arkona Basin were often lower than anthropogenically influenced freshwater sediments and more similar to a freshwater sediment core only influenced by deposition, with an additional Oder River inflow. Differences in patterns and contamination levels are discussed.

Identification of secondary metabolites from Streptomyces violaceoruber TU22 by means of on-flow LC-NMR and LC-DAD-MS.

For rapid screening of natural products from Actinomycetes, a combination of on-line couplings LC-NMR, LC-DAD-MS and HPLC-PDA, as well as MALDI-TOF-MS is particularly suitable. Simultaneous use of these coupling techniques provides considerable advantages for the rapid identification of natural compounds in mixtures. The results of our present investigation on secondary metabolite products of Streptomyces violaceoruber TU 22 showed that more than 50% of the identified metabolites are new compounds. The structures of four new polyketides (granaticin C, metenaticin A, B and C) as well as four known ones (granaticin A, granatomycin E, daidzein and genistein) have been elucidated using LC-NMR, LC-MS/MS and -MS(n) techniques in combination with two-dimensional NMR spectroscopy.

Toxicity and microcystin content of extracts from a Planktothrix bloom and two laboratory strains.

Toxic effects and microcystin content from various extracts of a Planktothrix agardhii bloom and two different strains of Planktothrix agardhii, HUB 076, and NIVA 34 were investigated. Extracts were obtained with solvents of different polarity such as hexane, dichloromethane, methanol, and water. Additionally, different pre-treatments were used to break the cells before extraction. Acute toxicity was determined with the fairy shrimp Thamnocephalus platyurus, subchronic effects were detected in embryos and larvae of the zebrafish Danio rerio. The extracts affected the test species to a different extent. Effects were severe in polar extracts (water and methanol) of all strains tested. Although the strain NIVA 34 did not contain any microcystins, aqueous extracts of this strain showed the highest acute toxicity to the crustacean species tested (LC50= 0.08 mg ml(-1)). In contrast aqueous extracts of the Planktothrix bloom containing high amounts of microcystins were less acutely toxic (LC50 = 0.46 mg ml(-1)). Our results indicate the existence of further toxic metabolites in different Plankorothrix agardhii strains.

On the contribution of background sources to the heavy metal content of municipal sewage sludge.

The role of human excretion, drinking water, and deposition as a source of heavy metals to municipal sewage was investigated and compared with common levels in sludge for soil application. These sources contributed more than half of the copper (Cu), zinc (Zn), and lead (Pb) content of municipal sewage sludge for soil application, while other sources dominated the fluxes of chromium (Cr) and cadmium (Cd). Drinking water was an important source for Cu and Zn. Deposition contributed about 40% to the Pb flux. Faecal excretion commonly caused less than 10% of the heavy metal load, while urinary excretion was here a negligible heavy metal source.

Source identification of PCDD/Fs in a sewage treatment plant of a German village.

The PCDD/F levels in the sewage sludge of a village in North-East Germany were substantially above the limit of 100 pg I-TEq/g for sludge applied to land. A study was initiated to identify the PCDD/F sources in the sewage of this treatment plant. It was found that the PCDD/F contamination entered the plant through the faecal inlet, where the content of faecal storage tanks was emptied into the treatment plant. The isomeric patterns of the higher chlorinated homologues were similar to that of PCP, while incineration showed some influence on the lower chlorinated homologues. Cluster analysis revealed a profile similar to that of PCP.

Contributions to the GC-MS-analysis of polyfluorinated dibenzo-p-dioxins (PFDD).

Polyfluorinated dibenzodioxins (PFDD) obtained by synthesis are investigated for their gas chromatographic and mass spectrometric behaviour. Kovats-indices of the investigated PFDD range between 1400 and 1600 on the unpolar column DB5, between 1500 and 1900 on the moderately polar column DB17 and between 2300 and 2800 on the strongly polar SP 2331. Thus PFDD elute between PFB and PCB. As for PCDD the molecular ion peak is the base peak for PFDD, too. However, other than for PCDD the second highest peak is the M-C(2)O(2)-peak for the lower fluorinated PFDD and the M-COF-peak for the higher fluorinated PFDD (directly followed by the M-C(2)O(2)-peak). PFDD also show intensive M(2+)-peaks. The intensity of C(x)F(y)-fragments increases with increasing degree of fluorination.

[Dioxins and polychlorinated biphenyls in indoor areas]. / Dioxine und polychlorierte Biphenyle im Innenraum.

Polychlorinated dibenzodioxins, dibenzofurans and polychlorinated biphenyls (PCB) today belong to the most significant and widespread contaminants. They are found in soil, sewage sludge, indoor and outdoor air, in food especially of animal origin as well as in breast milk. Based on available toxicological data the Federal Health Office and the Federal Office of the Environment suggested a tolerable daily intake (TDI) for PCB of 1-3 micrograms PCB/kg body weight in 1983 and for dioxins and furans of 1-10 pg TCDD toxic equivalents/kg body weight aiming at less than 1 pg equivalent in 1985. This allows for a risk assessment of indoor air pollution (for example in kindergartens, schools etc.). As a precaution the proportional daily intake of persistent environmental contaminants via indoor air should not exceed 10% of the TDI for longer periods. Step-by-step measures should be taken if there is any over stepping.