Environmental chemicals with known endocrine potential affect yolk protein content in the aquatic insect Chironomus riparius

The use of vitellogenesis as a marker for possible effects of endocrine disrupting agents on insects was tested in the aquatic midge Chironomus riparius. As test substances the synthetic ecdysoid tebufenozide, and the endocrine disruptors bisphenol a and 4-n-nonylphenol were applied in a semi-static manner. The yolk protein contents of freshly emerged (24 h) male and female midges were determined by an ELISA procedure. In males, where always low amounts of immunoreactivity were apparent, yolk concentrations were lowered by 10% after a 80 microg/l tebufenozide treatment, and by 20-25% after exposition to bisphenol a at concentrations of 1, 100, and 3,000 microg/l. 4-n-nonylphenol contamination caused an inverted dose-response curve. At low test concentrations (1.9-30 microg/l) reduced yolk immunoreactivity occurred, while at medium concentrations (120 and 500 microg/l) no significant effects were observable. In the most highly contaminated group (2,000 microg/l) yolk protein immunoreactivity was elevated to 107% of the control. Female yolk protein contents were affected only in the 3,000 microg bisphenol a/l contaminated group, where yolk immunoreactivity was reduced by ca. 10% compared to the control.     

Photolytic degradation of fluoroquinolone carboxylic acids in aqueous solution

Subsequent to irradiation with a xenon lamp simulating sunlight, fluoroquinolone carboxylic acids in aqueous solution form polar pyridone dicarboxylic and tricarboxylic acids. After liquid/liquid partition with chloroform/water these substances can be isolated by ion exchange chromatography of the aqueous phase. They can be regarded as intermediate compounds on the route to a complete photomineralization. The structural elucidation is performed by such mass spectroscopic methods as MS, GC/MS and HPLC/MS, whereby HPLC/MS shows the highest reliability. Additionally¹H- and¹³C-NMR measurements confirm the structure of the main polar degradation product.     

Quecksilber Erfassung von Immissionswirkungen Biomonitoring mit der Standardisierten Graskultur: Eignungstest

An approach to biomonitoring of immission-induced mercury contents (= immission effects) in standardized grass cultures was made at locations with different settlement structures and in the vicinity of two waste incineration plants in the context of a research project dealing with “Active biomonitoring of immission effects in the testing area of Munich”. In 1992, mercury could be found in most grass samples using the method of cold vapor atomic absorption spectrometry (CVAAS) with an analytical detection limit of 20 µg/kg dry mass. With a new detection limit of 5 µg/kg dry mass attained by a better analytical procedure, mercury could be detected in all grass samples of 1993. An influence of the two examined waste incineration plants on the mercury content in grass could not be detected, although a relationship between mercury contents in the standardized grass culture and settlement structures is indicated.     

Determining conservation priorities

One important component in achieving an optimal compromise between mineral development and environmental conservation is to rank different geographical areas according to their priorities for development and conservation respectively. The latter is considered here.There are three main steps in assigning conservation priorities: (i) acquisition and assessment of information on the existing baseline environment and on potential impacts; (ii) assignment of values to the environmental components concerned and integration of these to yield overall values for alternative possible conservation targets; and (iii) incorporation of logistic considerations to determine the practical priorities for conservation.One particularly critical aspect of this process is the relative significance of different conservation criteria, specifically including the presence of rare species, high diversity, pristine condition and representativeness. These criteria all reflect the same underlying conservation values, but their relative significance varies from case to case. Their integration is based on professional judgement rather than any formal algorithm and explicit guidelines for such judgement are needed to promote consensus in the determination of conservation priorities.     

Langzeitmonitoring möglicher Auswirkungen gentechnisch veränderter Pflanzen auf Pflanzengesellschaften Konzeptentwicklung am Beispiel von Raps (Brassica napus)

Ecological monitoring of genetically engineered plants (GEPs) is being developed in the Bavarian Environmental Protection Agency. Focusing on oilseed rape (Brassica napus, Cruciferae), a method is being established to measure the impact of the commercial release of GEPs on plant communities. Oilseed rape is known to escape from cultures and to establish outside the fields. It also produces hybrid offspring with wild relatives of the European flora. The study site is located in Bavaria (Germany) and comprises an area of 5700 ha. It is characterized by a mosaic of protected natural habitats in close vicinity to intensively cultivated farmland. In this region species composition and population density of Cruciferae is documented prior to a possible commercial release of GEPs. Furthermore Cruciferae of the study site are tested for the presence of transgenes. Therefore, plant material of selected Cruciferae is randomly sampled. We also test oilseed rape honey from the study site and pollen from pollen traps for the presence of hybrid pollen. The molecular method used is the ‘real-time PCR’. In addition, an intensive monitoring program is established in two types of biotopes, which are located in the study site. Multivariate statistics are being used to correlate plant community data with soil parameters.