Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota. Earthworms are key organisms of the soil ecosystem and are due to their crucial role in soil quality and fertility a suitable and popular model organism in soil ecotoxicology. Therefore, the aim of this study was to gain insight into the effects of environmentally relevant concentrations of microplastics on the earthworm Eisenia andrei on multiple levels of biological organization after different exposure periods. Earthworms were exposed to two types of microplastics: (1) polystyrene-HBCD and (2) car tire abrasion in natural soil for 2, 7, 14 and 28 d. Acute and chronic toxicity and all subcellular investigations were conducted for all exposure times, avoidance behavior assessed after 48 h and reproduction after 28 d. Subcellular endpoints included enzymatic biomarker responses, namely, carboxylesterase, glutathione peroxidase, acetylcholinesterase, glutathione reductase, glutathione S-transferase and catalase activities, as well as fluorescence-based measurements of oxidative stress-related markers and multixenobiotic resistance activity. Multiple biomarkers showed significant changes in activity, but a recovery of most enzymatic activities could be observed after 28 d. Overall, only minor effects could be observed on a subcellular level, showing that in this exposure scenario with environmentally relevant concentrations based on German pollution levels the threat to soil biota is minimal. However, in areas with higher concentrations of microplastics in the environment, these results can be interpreted as an early warning signal for more adverse effects. In conclusion, these findings provide new insights regarding the ecotoxicological effects of environmentally relevant concentrations of microplastics on soil organisms. © 2022 The Authors
Tropospheric ozone is an air pollutant that causes risks to human health and vegetation. This literature study summarises results of experiments, in which the effects of ozone on plants has been investigated in combination with factors of climate change, enhanced concentration of carbon dioxide in the air as well as nitrogen deposition. The results are needed for a sound risk assessment for plants under current and future environmental conditions. Such model-based risk assessments are the scientific basis for deriving and settling of measures for emission reduction of ozone precursors. Veröffentlicht in Texte | 29/2021.
In Germany, as in almost all industrial countries, active pharmaceutical substances can now be found in virtually all water bodies and occasionally also in drinking water. Even though the concentrations in question tend to be very low, there are initial signs of their impact on aquatic life. There is no evidence as yet of any acute consequences for human health. It is, however, impossible to rule out long-term consequences from these minimal concentrations or unexpected effects from the interaction between various active ingredients (cocktail effect). At special risk here are sensitive segments of the population such as children and the chronically ill. There is thus a need for action on precautionary grounds. Veröffentlicht in Leitfäden und Handbücher.
In assessing the effects of plant protection products (PPP) on organisms in soil it is crucial to predict accurately the environmental concentration (PECsoil) which organisms are exposed to. The PECsoil is depending on the spatial and temporal distribution of the PPP, arising from characteristics of the chemical (e.g. Kow, water solubility, degradability) and from soil parameters (e.g. pH value, TOC, texture). The potential effects of PPP on soil organisms depend -besides the concentration of the chemical in the soil matrix- on the spatial and temporal distribution of the animals, i.e., their exposure as well as their specific sensitivity to the chemical. A new approach for deriving environmental concentrations in soil is currently under discussion, taking the preferred soil depth of the organisms into account. We conducted two different outdoor studies in Terrestrial Model Ecosystems (TMEs) to monitor (1) the movement of pesticides in soil over time and (2) the exposure and effects on soil organisms during the same time. Additionally, an indoor TME study was conducted to measure the fate of the radiolabelled pesticides and the formation of non-extractable resi-dues in soil. In study [1] (outdoor) and [2] (indoor) Lindane (log Kow > 3) and Imidacloprid (log Kow < 1) were applied, two pesticides with different physico-chemical properties. In study [3] (outdoor), we investigated the effects of Carbendazim, a pesticide which is known as to be toxic for earthworms at certain concentrations. The effect analysis was conducted by means of different multivariate and univariate statistical methods. The synergistic conclusions based on the project results are proposed as recommendations for risk assessment concerning exposure and risk of soil organisms exposed to PPP under realistic conditions. Quelle: Forschungsbericht
Das Vorhaben hatte das Ziel, ausgehend von den Ergebnissen einer Literaturrecherche primär am Beispiel von Arsen ein Konzept zur Ableitung von vorsorgeorientierten Bodenwerten speziell für den Pfad Boden â€Ì Bodenorganismen auf der Grundlage der bioverfügbaren Anteile von (Halb-)Metallen zu erarbeiten. Zur praktischen Umsetzung wurden ökotoxikologische standardisierte Tests mit acht Bodenorganismen-Arten in sechs unterschiedlichen, bodenkundlich umfassend charakterisierten Feldböden durchgeführt, wobei die jeweilige Metallkonzentration mittels sechs Extraktionsverfahren unterschiedlicher Stärke bestimmt wurde. Für jeden Tests wurden die entsprechenden Effektkonzentrationen (EC10- bzw. EC50-Werte) berechnet. Die Stärke der verschiedenen Extraktionsverfahren nahm für As bei allen Böden in der Reihenfolge Königswasser > HNO3 > DTPA > Ca(NO3)2 >= CaCl2 > NH4NO3 ab. Anschließend wurden die Ergebnisse der in den verschiedenen Böden durchgeführten ökotoxikologischen Tests mit den jeweiligen chemischen Rückstandsdaten zusammengeführt, um diejenige Extraktionsmethode zu identifizieren, die die Bioverfügbarkeit am besten widerspiegelt. Zwei Ansätze zur Ableitung von Bodenwerten wurden identifiziert: entweder auf der Basis der geeignetsten Extraktionsmethodik oder auf der Basis des Gesamtgehalts mit anschließender Normalisierung anhand der jeweiligen Bodeneigenschaften, wobei sich letztere als besser geeignet erwies. Im Einklang mit der Struktur der Bundes-Bodenschutz- und Altlastenverordnung werden folgende vorsorgeorientierte Bodenwerte für die drei Bodenarthauptgruppen vorgeschlagen: Sand = 10 mg/kg; Lehm/Schluff = 30 mg/kg; Ton = 40 mg/kg. Sowohl in Hinsicht auf die in Deutschland vorkommenden Hintergrundgehalte von Arsen als auch im Vergleich mit den Bodenwerten anderer Staaten sind diese Werte als plausibel anzusehen. Analog zum Vorgehen bei Arsen wurden zwei Tests (Arthrobactertest, Regenwurm-Fluchttests) mit Nickel und Kupfer durchgeführt und die Ergebnisse zur Ableitung (zusammen mit vorhandenen Daten) vorsorgeorientierter Bodenwerte genutzt. Quelle: Forschungsbericht
Mecoprop-P (MCPP-P) is an auxin herbicide which has been used against dicotyledonous weed plants since the 1980s. While fate and monitoring data of MCPP-P in the aquatic environment revealing concentrations up to 103 ÎÌg/L in freshwaters are well documented, only very few toxicity data and no studies with dicotyledonous macrophytes have been published in open literature so far. To fill up this essential data gap, a microcosm study was conducted in order to test the sensitivity of nine dicotyledonous and one Ceratophyllales macrophyte species. The plant species were exposed to seven MCPP-P concentrations ranging from 8 to 512 (micro)g/L for 21/22 days in one microcosm per concentration, and two further microcosms served as controls. Plant preparation was adapted to each species and endpoints were measured to calculate growth rates. Data were generated to obtain effect concentrations (ECX) which then were used to construct species sensitivity distribution curves (SSD). Eight species proved to be sensitive to MCPP-P in the tested concentration range with EC50 values ranging from 46.9 (micro)g/L for Ranunculus aquatilis to 656.4 (micro)g/L MCPP-P for Ludwigia repens. Taking the EC50 values of this study and published data for autotrophic organisms into account, a hazard concentration (HC5) of 2.7 (micro)g/L was derived from the SSD curve, while an SSD curve without dicotyledonous macrophytes resulted in an about 100 times higher HC5 (360.8 (micro)g/L MCCP-P). This confirms that a re-evaluation for old auxin herbicides by including dicotyledonous test species into the environmental risk assessment may be indicated. Furthermore, the use of MCPP-P in bitumen felts as protection against rooting by plants is not in the focus of any risk regulation so far. This application, however, can lead to high run-off concentrations that can enter surface waters easily, exceeding the new regulatory acceptable concentration values. © 2021 The Authors
The IPCC 2021 report predicts rising global temperatures and more frequent extreme weather events in the future, which will have different effects on the regional climate and concentrations of ambient air pollutants. Consequently, changes in heat and mass transfer between the inside and outside of buildings will also have an increasing impact on indoor air quality. It is therefore surprising that indoor spaces and occupant well-being still play a subordinate role in the studies of climate change. To increase awareness for this topic, the Indoor Air Quality Climate Change (IAQCC) model system was developed, which allows short and long-term predictions of the indoor climate with respect to outdoor conditions. The IAQCC is a holistic model that combines different scenarios in the form of submodels: building physics, indoor emissions, chemical-physical reaction and transformation, mold growth, and indoor exposure. IAQCC allows simulation of indoor gas and particle concentrations with outdoor influences, indoor materials and activity emissions, particle deposition and coagulation, gas reactions, and SVOC partitioning. These key processes are fundamentally linked to temperature and relative humidity. With the aid of the building physics model, the indoor temperature and humidity, and pollutant transport in building zones can be simulated. The exposure model refers to the calculated concentrations and provides evaluations of indoor thermal comfort and exposure to gaseous, particulate, and microbial pollutants. © 2022 The Authors
Due to their beneficial properties, the use of zinc oxide nanoparticles (ZnO NP) is constantly increasing, especially in consumer-related areas, such as food packaging and food additives, which is leading to an increased oral uptake of ZnO NP. Consequently, the aim of our study was to investigate the cellular uptake of two differently sized ZnO NP (<50 nm and <100 nm; 12-1229 (micro)mol/L) using two human intestinal cell lines (Caco-2 and LT97) and to examine the possible resulting toxic effects. ZnO NP (<50 nm and <100 nm) were internalized by both cell lines and led to intracellular changes. Both ZnO NP caused time- and dose-dependent cytotoxic effects, especially at concentrations of 614 (micro)mol/L and 1229 (micro)mol/L, which was associated with an increased rate of apoptotic and dead cells. ZnO NP < 100 nm altered the cell cycle of LT97 cells but not that of Caco-2 cells. ZnO NP < 50 nm led to the formation of micronuclei in LT97 cells. The Ames test revealed no mutagenicity for both ZnO NP. Our results indicate the potential toxicity of ZnO NP after oral exposure, which should be considered before application. © 2021 by the authors
To document trends in human exposure to environmental pollutants, the German Environmental Specimen Bank (ESB) has been routinely collecting and archiving 24-h urine samples from young adults at four sampling sites in Germany on an annual basis. For the purpose of normalizing measured analyte concentrations, urinary creatinine (UC), specific gravity (SG), conductivity (CON), and total urine volume (UVtot) of 24-h urine samples have also been recorded. These parameters are however susceptible to variation over time, as well as within/among participants and normalization against them can thus affect the interpretation of data regarding exposure to environmental pollutants. To evaluate the influence of normalization against these parameters, we first sought to determine variations of these parameters with regard to differences between sexes and trends over time. We analysed data from 8619 urine samples collected from 1997 to 2016. We observed an inverse relation between UVtot and UC, SG, and CON. We also found differences between sexes for UC, SG and CON, but not UVtot. UC, SG, and CON showed significant decreasing trends over time in both sexes. In contrast, a significant increase of over 30% in UVtot, independent of participant age and BMI, was revealed. This increase in UVtot and the concomitant sample dilution is likely to have an impact on measured analyte concentrations in 24-h urine samples. Hence, normalization of urinary concentrations is warranted when interpreting time trends of human exposure. Next, urinary calcium (Ca2+) concentrations of ESB participants were used to demonstrate the effects of normalization against each of the four urine parameters. From 1997 to 2016, measured Ca2+ concentrations showed a statistically significant but scientifically implausible decrease. Normalization of Ca2+ concentrations against UVtot (by calculating the total daily excretion), UC, or CON, but not SG, eliminated this decrease. Consistent with previous work, Ca2+ concentrations in urine and total daily Ca2+ excretion were higher for males than females. Normalization against UC, SG, or CON, however, attenuated this difference. Thus, to avoid misinterpretation in trend analysis and sex-specific excretion in 24-h urine samples, the calculation of the total daily excretion is recommended.
In the first tier risk assessment (RA) of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, fungicides, and insecticides. However, fungi as key organisms for nutrient cycling in ecosystems as well as multiple pesticide applications are not considered in the RA. In this study, the effects of multiple low pesticide pulses using regulatory acceptable concentrations (RACs) on the dynamics of non-target aquatic fungi were investigated in a study using pond mesocosm. For that, fungi colonizing black alder (Alnus glutinosa) leaves were exposed to multiple, low pulses of 11 different pesticides over a period of 60 days using a real farmer's pesticide application protocol for apple cropping. Four pond mesocosms served as treatments and 4 as controls. The composition of fungal communities colonizing the litter material was analyzed using a molecular fingerprinting approach based on the terminal Restriction Fragment Length Polymorphism (t-RFLP) of the fungal Internal Transcribed Spacer (ITS) region of the ribonucleic acid (RNA) gene(s). Our data indicated a clear fluctuation of fungal communities based on the degree of leaf litter degradation. However significant effects of the applied spraying sequence were not observed. Consequently also degradation rates of the litter material were not affected by the treatments. Our results indicate that the nutrient rich environment of the leaf litter material gave fungal communities the possibility to express genes that induce tolerance against the applied pesticides. Thus our data may not be transferred to other fresh water habitats with lower nutrient availability. Quelle: http://www.sciencedirect.com
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