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Organisationseinheit der BAM
Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore-TM styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d-1 and time-weighted average (TWA) concentrations from 0.05 to 2.11 µg/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides.
A laboratory biofilm consisting of the phototrophic cyanobacterium Nostoc punctiforme ATCC 29133 and the rock-inhabiting ascomycete Knufia petricola CBS 726.95 was tested for its mineral weathering potential. Minerals with different grain sizes and mineralogy were incubated with and without biofilm in batch and in flow-through column experiments. After incubation, the mineral dissolution was quantified analysing (i) leachate chemistry via ICP-OES/MS (inductively coupled plasma optical emission spectrometry/mass spectrometry) and (ii) the residual grains as thin polished sections via SEM/TEM-EDX (scanning electron microscopy/transmission electron microscopy-energy dispersive X-ray spectrometry). Mineral dissolution was enhanced in biotic experiments as compared to abiotic ones, for both batch culture and flow-through approaches. Analyses of thin polished sections confirmed the leaching of these elements near the surface of the mineral grains. These results clearly indicate a biotic effect on the weathering of minerals produced by the laboratory biofilm.
Background and aims
Olive mill wastewater (OMW) generated in Mediterranean countries is partly disposed of on soil. Its underlying fate mechanisms and influences on plant growth are still largely unknown. Our goal was to understand OMW organic matter (OMW-OM) degradation in soil and its phytotoxic effects. We hypothesized that OMW phytotoxicity decreased with degradation of its phenolic components.
Methods
In a 60 day incubation study, we monitored soil respiration, extractable total phenolic content (TPC) and carbon isotope ratio (δ13C) of OMW treated Israeli soil. The soil was extracted using accelerated solvent extraction (ASE) and its extracts were exemplarily analyzed for four phenolic substances by LC/MS. Phytotoxicity of soil and soil extracts were tested using a Lepidium sativum seed germination bioassay.
Results
Soil respiration was 2.5 times higher for OMW treated soil with two respiration maxima and indicated a degradation of up to 27 % of the added OMW-OM. Four phases of OMW-OM degradation were identified: (i) degradation of easily degradable OMW-OM and transformation of phenolic compounds, (ii) intermediate suppression of phytotoxicity, (iii) degradation of phytotoxic phenolic compounds and (iv) significant physical immobilization of phytotoxic compounds.
Conclusion
Environmental conditions during and after OMW disposal on soil ought to favor fast degradation of OMW-OM, minimizing their physical immobilization and phytotoxic effects.
The European Construction Products Regulation allows Member States to adopt rules for evaluating the environmental impact of their buildings. The aim of the project was to develop recommendations for a test battery for the ecotoxicological assessment of the environmental impact of construction products for outdoor use and contribute to the European harmonization of test methods. From a shortlist of 39 products 20 products were included in the ecotoxicological testing program. Monolithic and plate-like construction products were eluted in the Dynamic Surface Leaching test (DSLT) in accordance with CEN/TS 16637-2, granular products were eluted in a one stage batch test in accordance with DIN EN 12457-1. The eluates were examined in four aquatic toxicity tests (algae, daphnia, luminescent bacteria, fish eggs), a genotoxicity test (umu test) and in the respirometer test (OECD 301 F). Here, low to very high ecotoxicity was observed (up to a dilution factor of 1536). Six out of 8 eluates, whose TOC exceeded 10 mg L⁻1 showed a good biodegradability above 75%. The intra-laboratory repeatability of the Lowest Ineffective Dilution (LID) usually was within ±1 dilution steps (ecotoxicity tests) and ±2 dilution steps (leaching and ecotoxicity tests). This is acceptable, when considering that the overall variability of sample preparation, leaching test, and bioassays add up. The conclusions lead to practical recommendations for a suitable combination of leaching and ecotoxicity tests.
Recycled plastic granules of high-density polyethylene, polyvinyl chloride and polystyrene the size of microplastics were exposed to artificial aging conditions (2000 h; photooxidative and thermo-oxidative) to simulate their fate outdoors. Their potential to leach into water during the aging process was investigated using column percolation tests.
Aging-related changes on the surface of the material were characterised by IR measurements indicating oxidation reactions with the formation of new adsorption bands (C=O, C–O and OH), especially in the case of photooxidative aging.
These findings were confirmed by the identification of leachable organic compounds. Leaching of total organic carbon, Cl, Ca, Cu and Zn is clearly affected by changes due to aging, and their release is increased after photooxidative aging.
In general, exposure to photooxidative conditions shows a greater influence on aging and thus on leaching and seems to be the more important mechanism for the aging of microplastic in the environment. Comparison with the total content of inorganic species revealed that, for most elements, less than 3% of the total content is released after 2000 h of photooxidative aging.
Influence of weathering on the leaching behaviour of zinc and PAH from synthetic sports surfaces
(2017)
Synthetic materials used for outdoor sports grounds consist of a mix of inorganic, organic and polymeric compounds that show ageing due to weathering and a complex leaching behaviour by percolation of rainwater, which can limit its lifetime. Additionally, weathering exposure induces degradation processes in the polymers, which leads to the formation of new surfaces allowing water to access additional reservoirs of leachable compounds. A laboratory test comprising artificial weathering, ozonisation and subsequent leaching was developed to investigate this behaviour in a reproducible and controllable way. The experiments showed a general decline of Zn, polycyclic aromatic hydrocarbons (PAH) and total organic carbon (TOC) concentrations after an initial increase. Within this general trend, the course of concentration over exposure duration is very specific for individual sample materials and the analyte under investigation. The results indicate that weathering and degradation behaviour cannot be predicted from initial material conditions. Thus, weathering experiments are recommended to fill this gap of knowledge.
Construction products are in contact with water (e.g., rain, seepage water) during their service lifetime and may release potentially harmful compounds by leaching processes. Monitoring studies showed that compounds attributed to construction products are found in storm water and the receiving bodies of water and that the release of biocides in urban areas can be comparable to the input of pesticides from agricultural uses. Therefore, a prospective risk assessment of such products is necessary. Laboratory leaching tests have been developed by the Technical Committee CEN/TC 351 and are ready to use. One major task in the future will be the evaluation of the leaching test results, as concentrations found in laboratory experiments are not directly comparable to the field situations. Another Task will be the selection of compounds to be considered for construction products, which are often a complex mixture and contain additives, pigments, stabilization agents, etc. The formulations of the products may serve as a starting point, but total content is a poor predictor for leachability, and analysis of the eluates is necessary. In some cases, nontargeted approaches might be required to identify compounds in the eluates. In the identification process, plausibility checks referring to available information should be included. Ecotoxicological tests are a complementary method to test eluates, and the combined effects of all compounds—including Degradation products—are included. A bio test battery has been applied in a round robin test and was published in a guidance document. Published studies on the ecotoxicity of construction products show the tests’ suitability to distinguish between products with small and larger effects on the environment.
Draft standards for the determination of organic pollutants in the solid matter of environmental matrices such as sludge, treated biowaste and soil have been basically developed in the framework of the European standardization project HORIZONTAL. A research project financed by the German Federal Environment Agency was initiated to finalize some of these CEN standard drafts, since fully validated standard procedures are crucial for the evaluation of their reliability in the context of implementation in legislation on environmental health.
Approach: Appropriate test materials (< 2mm particle size) were prepared and homogenized from contaminated soils, sludge and treated biowaste containing polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), dioxins, furans and dioxin-like-PCB and served, along with reference solutions, as the basis for international interlaboratory comparisons. Performance data of three analytical standard procedures were obtained by the statistical evaluation of results received from 11 to 29 participants per test material.
Results: The overall variation coefficients of reproducibility (between-lab standard deviations) for the sum parameters were roughly between 10 and 35 %. The variation coefficients of repeatability (within-lab standard deviations) range between 3 % and 8 % and show no trend considering the substance groups or matrices.
The highest coefficients of reproducibility were found for the analysis of PAHs, which were between 26 and 35 %, depending on the matrix, whereas 7-17 % reproducibility was observed for toxicity equivalents (TEQ) comprising dioxins, furans and dl-PCB.
Conclusions: Overall, the results confirm that the procedures described in the Technical Specifications are fit for purpose for all three matrices and that the feasibility of the HORIZONTAL approach, to cover several matrices with one standard per analyte, was thereby proven.
Column tests are a common tool to investigate the leaching behavior of contaminated soil and waste materials. In contrast to inorganic analytes, fewer studies with organic contaminants are available based on column tests. This paper is aimed at the question if soil materials contaminated with organic pollutants can be reliably investigated by column tests. Soils contaminated with TPH (total petrol hydrocarbons), PFC (perfluorinated surfactants) and the biocide tebuconazole were used for column percolation tests. Differences in the leaching behavior are mainly driven by partitioning behavior between organic carbon and water, which can be estimated from log KOW values and size and shape of molecules. PFC show higher release (10–50% for individual compounds) than pesticides (3.7–5.3%) and TPH (< 1%) at liquid to solid ratio of 4 l/kg. All eluate concentrations are low with maximum concentrations of 50 µg/l for PFC and 1–2 mg/l for pesticides and TPH. Despite this, the observed standard deviations are quite small suggesting good repeatability. In general the observed concentration trends are similar to that from lysimeter studies found in the literature and thus, it can be concluded that laboratory column experiments are a reliable tool for organic compounds with various physico-chemical properties.
Background: An Annex XV restriction dossier for cadmium in artists’ paints was submitted by an EU member state to the European Chemicals Agency ECHA. By cleaning used brushes under the tap cadmium can enter the food chain via waste water treatment and subsequent agricultural application of the sewage sludge. It was estimated that 110 kg Cd per year is spread on agricultural land via this exposure route. Other sources of Cd amount to almost 120 tons per year.
Results: The mobility of Cd from pigments was studied in a field-like scenario by leaching experiments using soil samples amended with sewage sludge and spiked with Cd pigments in percolation columns. The redox conditions were confirmed to be the decisive factor for the release of Cd. The release of Cd from artists’ paints was in most cases 1% or lower in the experiments performed.
Conclusions: Application of sewage sludge containing Cd from artist paints does not increase the amount of Cd leached from this soils. Furthermore the quantity of Cd from artists’ paints calculated in the restriction dossier is negligible compared to other sources of Cd to agricultural soil. Therefore ECHA did not consider the proposed restriction to be the most appropriate EU wide measure to address the negligible level of risk.