Monitoring of Bt-Maize pollen exposure in the vicinity of the nature reserve Ruhlsdorfer Bruch in northeast Germany 2007 to 2008

Background, aim, and scope Basically, technological innovations are associated with benefits and risks. This is also true for the introduction of genetically modified organisms (GMO) into agriculture. In Germany, precautionary regulations currently demand isolation distances (i.?e. buffer zones) for the cultivation of genetically modified maize (Bt-maize) in the vicinity of conventional (150?m) and organic maize fields (300?m). The Bt-toxin may harm non-target organisms (NTO) such as Lepidoptera. Despite this, corresponding regulations for the protection of nature reserves are lacking to date. Conventional and Bt-maize have been grown in the vicinity of the Flora-Fauna-Habitat (FFH) Ruhlsdorfer Bruch in Brandenburg, Germany. The aim of this study was to investigate whether exposure of maize pollen from surrounding Bt-maize fields to NTOs in the nature protection area could be excluded or not. Two types of exposure were investigated: Firstly, whether maize pollen was dispersed by wind into the nature reserve area exposing resident NTOs. Secondly, foraging NTOs from the nature reserve are exposed by roaming the surrounding fields and collecting maize pollen. In order to fulfil the precautionary principle defined by law, the study should help to determine appropriate isolation distances for the cultivation of Bt-maize with regard to sustainable protection of NTOs in the FFH Ruhlsdorfer Bruch. In 2007, the local authorities issued an isolation distance between Bt-maize fields and nature reserves of 100?m and in 2008, this became 250?m in the northern and 500?m in the westerly direction, respectively. Materials and methods Standardised methods for biological and technical pollen sampling issued by the Association of German Engineers (VDI 4330 Part 3, 2007 and VDI 4330 Part 4, 2006) were applied providing a quality controlled and methodologically harmonised database which does not only serve the needs to be fulfilled by the present case-specific monitoring study but can also be used as a reference database for further investigations. Maize pollen exposure was measured within the FFH Ruhlsdorfer Bruch and its immediate vicinity in July and August 2007 and 2008. In 2007, the sampling was performed at three sites using 12 technical samplers (Sigma-2/PMF) placed at five measuring points at distances from 5?m to 120?m from the maize field edges. Additionally, for biological pollen sampling six bee colonies were situated at these three sites (two colonies at each site). The technical sampler Sigma-2/PMF enables point sampling which is primarily influenced by wind and topography providing information on effective maize pollen input (flow and deposition) at the measuring sites. Honey-bees roaming in the surrounding area with typical foraging distances of several kilometres may act as planar collectors. They may serve as indicators for the exposure to pollen-collecting NTOs. Furthermore, biological sampling is more selective due to the organism’s preferences, whereas the technical sampling is neutral. Hence, both the technical and the biological sampling complement each other in their scope of application. The pollen samples of both matrices were analysed microscopically and the maize pollen loads were quantified. Pollen-DNA was analysed by means of the quantitative PCR-method (qPCR) identifying conventional and Bt-maize pollen by two independent laboratories. In 2008, the monitoring was repeated with additional sites. Eighteen technical samplers were exposed at five sites with eight measuring points at distances from 5?m to 250?m from the maize field edges. Two honey-bee colonies for biological sampling were placed at one site for control purposes. PCR-analyses were performed to measure the amounts of Bt-maize pollen in the samples. Results The results of pollen monitoring at the Ruhlsdorfer Bruch revealed maize pollen exposure for all monitoring sites in both surveys. In 2007, up to 1.75 million maize pollen/m² were deposited at sites closest to the maize field. At 120?m from field edge in the middle of the FFH-reserve, 99,000 maize pollen/m² were detected. In 2008, similar results were found, at distances up to 250?m from the field edges deposition of 164,000 maize pollen/m² was detected. Data on maize pollen deposition show a clear distance relationship and are in accordance with results of further comprehensive surveys based on the same methodology (Hofmann 2007). The results of the microscopic analysis of the pollen pellets demonstrated that bees collected maize pollen at all sites, in 2007 and 2008. Although maize pollen is not the main food source (2007:0.1–0.3?%; 2008:2–3?%) the collection efficiency of the bee colonies resulted in high amounts of sampled maize pollen with 4 to 11 million per site in 2007 and up to 467 million in 2008. Molecular-biological analysis of maize pollen DNA by qPCR demonstrated that transgenic Bt-MON810 DNA was present in all technical and biological samples, corroborated by two independent laboratories. In 2007, the GMO-content in the samples ranged up to 44?% in the bioaerosols and 49?% in the pollen pellets. In 2008, GMO-proportions of up to 18?% were detected. Discussion The results of this study provide evidence that NTOs in the Ruhlsdorfer Bruch were exposed to Bt-maize pollen under the cultivation conditions in 2007 with a buffer zone of 100?m. The GMO-content reached up to 48?%. The results of the monitoring in 2008 confirmed these findings. Even though the exposure could be reduced by increasing the isolation distances to 250?m and 500?m respectively, the results still show percentages of up to 18?% Bt-MON810 in the pollen samples. The results on maize pollen deposition at the Ruhlsdorfer Bruch in 2007 and 2008 correspond to the results of an investigation which was conducted over several years applying the same standardised method, but covering a wider range of distances. The correlation between maize pollen deposition (n/m²) and distance to the source field (m) fitted best to a power function of the type y = 1.2086 · 10⁶ · x ^–0.548. Despite the same trend, the pollen deposition in the Ruhlsdorfer Bruch revealed above-average findings. Also the analysis of the pollen pellets collected by the bees showed an exposure in 2007 with values for the GMO-content of up to 49?%. For both methods, the exposure decreased in 2008 due to the greater buffer zones up to 500?m. Whereas the GMO-content for the biological sampling were reduced to values below 10?%, the values for the technical sampling were still higher indicating that greater buffer zones would be necessary for safety reasons under the precautionary principle. Conclusions The results of this investigation proved that maize pollen were dispersed by wind to distances farther than 250?m from field edge leading to maize pollen exposure in the centre of the nature reserve. The results also demonstrated that foraging NTOs living in the nature reserve were exposed to maize pollen from surrounding fields. Considering the cultivation of Bt-maize MON810, the assumption of the Environmental Risk Assessment (ERA) that there will be no relevant exposure beyond the Bt-maize fields, cannot be confirmed. Considering the results of this and related studies and with respect to the precautionary principle, one can state that buffer zones between Bt-maize fields and protected areas are an effective measure to minimise the exposure of Bt-maize pollen to NTOs and, thus, to prevent from adverse effects. Recommendations and perspectives Because of still insufficient ecotoxicological data for the risk assessment of Bt-maize MON810 considering butterflies and other protected NTOs, protection standards assuring the precautionary principle have to be implemented to avoid Bt-maize pollen exposure to NTOs. This applies for the case Ruhlsdorfer Bruch and for nature reserve areas in general. In order to exclude risks to protected NTOs occurring in nature reserves, sufficient buffer zones for Bt-maize cultivation should be considered. The statistical analysis revealed that distances of more than 500?m are necessary to decisively reduce exposure to foraging insects. In fact, distances of more than 1,000?m are necessary to prevent maize pollen deposition from values above 100,000 pollen/m² with a certainty of 90?%. An adequate risk assessment can only be attained if based on field measurements accounting for the high variation of pollen deposition due to local environmental site conditions and field management. The monitoring should be based on standardised methods. It should include locations with the highest expected deposition rates, the boundaries of the protected areas and sites of interest within those boundaries, e.?g., specific habitats of sensitive species.     

Die Bedeutung des organischen Kohlenstoffs im Unterboden

The organic carbon distribution among holorganic, topsoil, and subsoil horizons was determined for a series of 103 forest soils. The results show that only 25% and 36% of total organic carbon are stored within holorganic layers and topsoil, respectively. Subsoil was found to be the most significant compartment representing 39% of the carbon pool. This kind of distribution emphasizes the great importance of future research on structure and stability of subsoil organic carbon.     

Rechts- und naturwissenschaftliche Kooperation im Umweltrecht am Beispiel des Chemikalien- und Naturschutzrechts

This article is based on a speech held at the annual conference of the German Chemical Society (working group Environmental Chemistry and Ecotoxicology) on 23 September 2009 in Trier. Despite strong arguments for interdisciplinary co-operation in the field of law and natural sciences, it still appears as a rather rare phenomenon in the current research environment. This is partly due to the difficulties emerging from the increasing specialization and diversification in sciences. Beyond that, the current possibilities of third-party funding, not least aimed at initiating and intensifying interdisciplinary projects, provide a comparatively weak incentive to jurists. Nonetheless, there are indications for a change in the near future. However, at least chemical law (as well as for example nature conservation law) offers a range of starting points for a productive co-operation among jurists and natural scientists.     

Die Endigung afferenter Fasern der Seitenliniennerven im Mittelhirn des Dorsches Gadus morhua

The brain of a cod, Gadus morhua L., caught with damaged lateral lines, has been investigated histologically. Injured ganglion cells in the tuberculum acusticum and atrophic Mauthner-cells are demonstrated by staining with gallocyanin, lateral nerve fibres in the mesencephalon by employing Gleessilver impregnation. Terminals of degenerating lateral nerve fibres could be identified as “boutons terminaux”. The course of the afferent fibres from the lateral line through the metencephalon into the mesencephalon is as follows: Fibres of the lateral-line nerve, directly injured by an inflammation, run from the damaged lateral line to their ganglion cells in the tuberculum acusticum in the medulla; the ganglion cells are degenerated to the limits of visibility; from these cells fibres run to the Mauthner-cells, which became atrophic due to lack of afferent impulses. Other fibres run from the tuberculum acusticum into two regions of the subtectum in the mesencephalon, where they terminate in axo-somatic synapses.     

PCDD/PCDF-Bodengehalte im Umfeld von Verbrennungsanlagen

In connection with law-imposed waste disposal regulations concerning the modernisation of the incineration ?Munich-North“, local authorities and residents raised objections. Based on an immission calculation using a numerical model concerning the impact of PCDD/PCDF on the soil (study I), conclusions were drawn that the former immissions were so high that further impact on the soil by a new combustion plant was no longer tolerable. The results of study I were controlled using a different numerical model calculation (study II). The simulation results varied vastly because of the differences in preliminary input parameters. In order to verify the simulations, soil samples were taken and the content of PCDD/PCDF was determined. Predicted soil-contents of study II were in the same range as the analyzed samples, whereas the values of study I were higher. With one exception, the soil contents were less than 5 ng TEQ-BGA kg^?1 m_T, a value below the BGA limits. Calculations by numerical modelling, compared to the measurement of PCDD/PCDF soil contents, are therefore no reliable basis for predicting PCDD/PCDF concentrations in soils which has been induced by incineration emission.     

Verhalten von PAK im system boden/Pflanze

The results of lysimeter experiments conducted since 1991 dealing with the behavior of PAH in soil/plant systems demonstrate that the PAH pollution to cultivated plants may be caused by both atmospheric deposition and by the soil-to-plant transfer observed in contaminated sites. In the latter, a “direct contamination” of plant surfaces with PAH-loaded soil particles and the subsequent PAH turnover by desorption/adsorption processes is seen to dominate—at least for the most relevant PAHs toxic to humans, benzo(a)pyrene and dibenz(a,h)anthracene. Leafy vegetables growing close to the soil surface are therefore endangered most by a PAH contamination of the soil. The soil-to-plant transfer via “direct contamination” can be reduced to a high degree by covering the contaminated soil with different mulch materials. Systematic PAH transfer via root uptake could not generally be observed. From the reported results, a trigger value in the soil of 1 mg·kg^?1 for benzo(a)pyrene is proposed to make a judgement on PAH contaminated soils with regard to the soil-to-plant transfer pathways. Soils with excessive concentrations of benzo(a)pyrene demand special attention when considering the recommendations for the growth and consumption of cultivated vegetables. The “soil”as well as the “deposition pathways” must be integrated into a complete risk assessment of locations with food plant production, especially in urban areas.     

Teil 3: PCDD/F im Blutfett ausgewählter Personen

This study was designed to assess the degree of exposure to PCDD/F in 56 selected persons living in the vicinity of a former copper smelter located in Marsberg, Germany. The copper smelter was in operation until 1945. In 1991, high levels of PCDD/F were found particularly in materials from the slag dumps (10 000 – 100 000 ng TE/kg). The levels of PCDD/F in blood fat were used as parameters for individual PCDD/F exposure. Since only limited reference data for PCDD/F in human blood were available, blood samples of a reference group were analyzed in the same way. The criteria were collected from a group matched for sex, age (±3 years) and body mass. The median NATO/CCMS-Toxicity equivalency values (NATO/CCMS-TE-values) of the Marsberg group (43,2 pg NATO/CCMS-TE/g blood fat) and the reference group (43,0 pg NATO/CCMS-TE/g blood fat) were similar, whereas the arithmetic mean of the Marsberg group (52,7 pg NATO/CCMS-TE/g blood fat) was higher than that of the reference group (44,4 pg NATO/CCMS-TE/g blood fat). The frequency distribution of the individual TE-values of the Marsberg group was slightly shifted toward higher values. The individuals of the Marsberg group had significantly higher levels of PentaCDF, HexaCDF and HeptaCDF on average than the individuals of the reference group. On the basis of TE-values, the majority of the individuals from Marsberg did not have an increased body burden of PCDD/F. However, some individuals could be identified with TE-values exceeding background levels ranging up to 231 pg NATO/CCMS-TE/g blood fat. Although it must be assumed that the unusual congener pattern found in many of the test subjects is a result of ingestion of contaminated slag material or soil, the findings of this study could not verify this fact.     

Epiphytische Flechten im Wandel von Immissionen und Klima • Ergebnisse einer Vergleichskartierung 1989/2007 in Nordwestdeutschland

Epiphytic lichens as indicators for changes in air pollution and climate. Results of a comparative survey 1989/2007 in north-west Germany Background, aim, and scope Lichens growing on tree bark (epiphytic lichens) respond very sensitively to environmental effects such as chemical substances and air temperature. Therefore, they are used as biomonitors for atmospheric pollution in environmental assessments. Based on a survey of epiphytic lichens in 1989, a repetition was performed in an intensively-used agricultural area of north-west Germany in 2007. The objective of this study was to assess possible changes in air pollution and climate. Materials and methods The study is based on a comparative inventory of epiphytic lichens, growing on 335 trees at 45 monitoring sites. A simplified half quantitative survey technique of the first survey was used. Results Indeed, major changes to the epiphytic lichen flora were found. Overall, nearly all monitoring points showed an increase in the level of lichen species. A sharp decrease in acidophileous species and a sharp increase in basidophileous and nitrophileous species were detected. In addition, an increase in thermophileous species which are mainly inhabitants of southern European countries was observed, combined with decreases in boreo-montanic species. Discussion These trends correspond with supra-regional observations. They are primarily attributed to changes in air pollution involving a decrease in SO₂ and an increase in NH₃ concentrations. Clear effects from climate change are evident as well. Conclusions Changes to epiphytic lichens over a 18-year period could be demonstrated using a relatively low-cost investigation. They are relevant for assessing the changing environmental situation, which is of great importance for other organism groups and ecosystems. Recommendations and perspectives Using standardized techniques epiphytic lichens are suitable bioindicators for obtaining different types of information about the air pollution in urban areas and in intensively-used agricultural regions. Furthermore they are obviously good indicators of temperature changes in their environment. More research is needed about the suitability of epiphytic lichens for a biomonitoring of climate changes.     

Empfehlung des Länder-Arbeitskreises “Bioindikation/Wirkungsermittlung” für die landesweite Erhebung von Immissionswirkungen mit Bioindikatoren

The working group on “boindication/assessment of effects” is made up of specialists active in the fields of bioindication and emission ecology for the German Federal administrative offices concerned with the protection of the environment and for the Geman Environmental Protection Agency. In April 1996, this working group adopted the recommendation for a “countrywide survey on the effects of emissions using bioindicatiors”. The goal of this national survey is to determine the geographic distribution and the development over time of such emissions, as well as to document the effects of background emissions. In order to achieve these goals, the development of national measuring networks and permanent observation stations is mandatory. A minimal demand of investigations and of investigative procedures is required in order to compare the results of the individual Federal States and to consequently combine these findings as an overall picture for the entire Federal Republic of Germany. Mosses and lichens are recommended for passive biological monitoring, while standardized grass cultures, kale, stinging nettle and tobacco are suggested for active biomonitoring. In addition, detailed methodical recommendations concerning the use of standardized grass cultures and kale are discussed.