Brandkatastrophe in Schweizerhalle 1986 — Rückblick und Bilanz

Background

On November 1st 1986, a fire at a Sandoz Ltd. storehouse at Schweizerhalle, an industrial area near Basel, Switzerland, resulted in a chemical contamination of the environment. The storehouse, which was completely destroyed by the fire, contained pesticides, solvents, dyes, and various raw and intermediate materials. The majority of the approximately 1,250 tons of stored chemicals was destroyed in the fire, but large quantities were introduced into the atmosphere, into the Rhine river through runoff of the fire-fighting water and into the soil and groundwater at the site. The chemicals discharged into the Rhine caused massive kills of benthic organisms and fish, particularly eels and salmonides. The public and private reaction to the fire and the subsequent chemical spill was very strong. This catastrophe happened only a few months after the Chernobyl accident and destroyed the myth of the immunity of Switzerland.

Aim

This article reviews the damaging events of November 1986 and aims at striking the balance two decades later.

Results and Discussion

In the aftermath of this once-per-century accident, it was the aim was to gain increased knowledge and understanding in the environmental sciences and to achieve progress for water pollution control issues.The following themes are discussed: Mitigation measures by the chemical industry and by the governmental authorities, activities of environmental protection organisations, chemical and biological monitoring, alert organisation, ecological damages, ecotoxicological effect assessment, recovery and alteration of river biology, return of the salmon, drinking water supplies, research programs, education of environmental scientists and visions for the future.

Conclusions

The catastrophic pollution of the Rhine in November 1986, and the obvious damages of the river biology, triggered significant progress towards the prevention of such environmental catastrophes. The crucial risk reduction measures in the chemical industry, legal regulations and controls as well as chemical and biological monitoring of the river water quality were substantially improved. Politics and chemical industry learned their lectures and proceeded accordingly.

Recommendations

Such a drastic acute contamination, as happened at Schweizerhalle in 1986, is clearly recognizable by the toxic effects. This led to long-term mitigation activities. However, also the less obvious effects of chronic water pollution should receive more attention as well as the on-going alteration of the biocenosis. A high water quality must be demanded in terms of using the Rhine water for drinking water supply. In that context, micropollutants should also be considered, and particular attention should be paid to emerging contaminants.

Perspectives

The big chemical storehouse fire of 1986 induced the transboundary cooperation and improved the willingness for international cooperation. Overall, the effects of the fire catastrophe are positive in terms of a long-term perspective. The whole-basin approach is, on a global basis, an example for other, even more heavily polluted river systems.

     

Schwermetalle in Regenwürmern Baden-Württembergs

Goal and Scope

The heavy metal burden of the soil and of earthworms from representative long-term forest observation plots has been measured since 1984 as one component of the media-embracing environmental monitoring network of the State of Baden-Wuerttemberg. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis

Methods

So-called characteristic curves for the metals Cd, Cu, Ni, Pb, and Zn were developed for the assessment. Earthworm toxicity data and background values in soil served as criteria. This procedure facilitates a comparative assessment of different pollutants. The mobility of the metals, which greatly influences their bioavailability and toxicity, was taken into account for the effects assessment.

Results and Conclusion

Besides inventorying the heavy metals (Part 1), the question of threshold values for toxic reactions as well as for accumulation was raised. The metal concentrations were assessed in the soil with regard to its habitat function. The ecotoxicological assessment revealed that the heavy metal burden of the investigated plots lies within the background- or precautionary range, well below the screening value established here to indicate the effect threshold in earthworms. This result means that a pollution of the forest observation plots with the metals cadmium, copper, lead, nickel, and zinc is low or absent. Only the distribution of the lead content is centered slightly above background (but clearly below the toxicity threshold). This slight lead burden of the soil of the observation plots can be explained by emissions from motor vehicles. Investigations at sites that are contaminated with either chromium or copper or cadmium showed that an accumulation of these metals in the body of the worms can be observed only above a threshold concentration of several hundred micrograms of mobile metal per kilogram in the upper layer of the soil.

Recommendations and Perspectives

The hitherto unknown threshold values for the accumulation in the body of the earthworm should be statistically validated and extended to other elements. Further research is needed in order to build a well founded basis for the ecotoxicological assessment of soil pollution. Acute and chronic earthworm effect thresholds are neither available yet for arsenic, cobalt, and mercury nor for some other elements occurring less frequently as soil pollutants. Background values depending on the kind of rock have been measured so far for total chromium only. They are lacking for the more toxic chromium (VI) which is a frequent soil pollutant but naturally occurs in traces only.     

Phosphate-induced differences in stabilization efficiency for soils contaminated with lead,zinc, and cadmium

Phosphates can cost-effectively decrease the mobility of Pb in contaminated soils. However, Pb always coexists with other metals in soil, their competitive reactions with phosphates have not been tested. In this study, the abilities of KH₂PO₄, K₂HPO₄, and K₃PO₄ to stabilize Pb, Zn, and Cd in soils contaminated with a single metal or a ternary metal for different phosphorus/metal molar ratios were investigated. Results indicated that the stabilization efficiency of KH₂PO₄, K₂HPO₄, and K₃PO₄ for Pb, Zn, and Cd in single metal contaminated soil (P/M ratio 0.6) was 96.00%–98.74%, 33.76%–47.81%, and 9.50%–55.79%, respectively. Competitive stabilization occurred in the ternary system, Pb exhibited a strong competition, the stabilization efficiency of Zn and Cd reduced by 23.50%–31.64%, and 7.10%–39.26%, respectively. Pyromorphite and amorphous lead phosphate formed with excess KH₂PO₄ or K₂HPO₄ addition, while K₃PO₄ resulted in the formation of a hydroxypyromorphite precipitate. Amorphous Zn and Cd phosphates and hydroxides were the primary products. The immobilization rate of Zn and Cd depends on pH, and increased significantly in response to the excess phosphate application. This approach provides insight into phosphate-induced differences in stabilization efficiency in soils contaminated with multiple metals, which is of theoretical and engineering significance.

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Modelling spatial patterns of correlations between concentrations of heavy metals in mosses and atmospheric deposition in 2010 across Europe

Background

This paper aims to investigate the correlations between the concentrations of nine heavy metals in moss and atmospheric deposition within ecological land classes covering Europe. Additionally, it is examined to what extent the statistical relations are affected by the land use around the moss sampling sites. Based on moss data collected in 2010/2011 throughout Europe and data on total atmospheric deposition modelled by two chemical transport models (EMEP MSC-E, LOTOS-EUROS), correlation coefficients between concentrations of heavy metals in moss and in modelled atmospheric deposition were specified for spatial subsamples defined by ecological land classes of Europe (ELCE) as a spatial reference system. Linear discriminant analysis (LDA) and logistic regression (LR) were then used to separate moss sampling sites regarding their contribution to the strength of correlation considering the areal percentage of urban, agricultural and forestry land use around the sampling location. After verification LDA models by LR, LDA models were used to transform spatial information on the land use to maps of potential correlation levels, applicable for future network planning in the European Moss Survey.

Results

Correlations between concentrations of heavy metals in moss and in modelled atmospheric deposition were found to be specific for elements and ELCE units. Land use around the sampling sites mainly influences the correlation level. Small radiuses around the sampling sites examined (5 km) are more relevant for Cd, Cu, Ni, and Zn, while the areal percentage of urban and agricultural land use within large radiuses (75–100 km) is more relevant for As, Cr, Hg, Pb, and V. Most valid LDA models pattern with error rates of <?40% were found for As, Cr, Cu, Hg, Pb, and V. Land use-dependent predictions of spatial patterns split up Europe into investigation areas revealing potentially high (=?above-average) or low (=?below-average) correlation coefficients.

Conclusions

LDA is an eligible method identifying and ranking boundary conditions of correlations between atmospheric deposition and respective concentrations of heavy metals in moss and related mapping considering the influence of the land use around moss sampling sites.

     

Photodegradation of Ibuprofen,Cetirizine, and Naproxen by PAN-MWCNT/TiO<Subscript>2</Subscript>–NH<Subscript>2</Subscript> nanofiber membrane under UV light irradiation

Background

In this study, the photodegradation of three pharmaceuticals, namely Ibuprofen (IBP), Naproxen (NPX), and Cetirizine (CIZ) in aqueous media was investigated under UV irradiation. The photocatalyst used in this work consists of surface functionalized titanium dioxide (TiO₂–NH₂) nanoparticles grafted into Polyacrylonitrile (PAN)/multi-walled carbon nanotube composite nanofibers. Surface modification of the fabricated composite nanofibers was illustrated using XRD, FTIR, and SEM analyses.

Results

Sets of experiments were performed to study the effect of pharmaceuticals initial concentration (5–50 mg/L), solution pH (2–9), and irradiation time on the degradation efficiency. The results demonstrated that more than 99% degradation efficiency was obtained for IBP, CIZ, and NPX within 120, 40, and 25 min, respectively.

Conclusions

Comparatively, the photocatalytic degradation of pharmaceuticals using PAN-CNT/TiO₂–NH₂ composite nanofibers was much more efficient than with PAN/TiO₂–NH₂ composite nanofibers.

     

Toxicity of metals to tadpoles of the common Sunda toad,Duttaphrynus melanostictus

Tadpoles of the common freshwater Sunda toad, Duttaphrynus melanostictus (Amphibia, Bufonidae), were exposed for a 4-day period under laboratory conditions to copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminum (Al), and manganese (Mn) at various concentrations. Mortality was assessed and median times of death (LT₅₀) and lethal concentrations (LC₅₀) were calculated. LT₅₀ and LC₅₀ increased with the decrease in mean exposure times and concentrations for all metals. LC₅₀ (96?h) for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.03, 0.3, 4.2, 1.5, 8.8, 0.4, 1.9, and 39?mg?L^?1, respectively. Cu was the most toxic to D. melanostictus, followed by Cd, Fe, Al, Pb, Zn, Ni, and Mn (Cu?>?Cd?>?Fe?>?Al?>?Pb?>?Zn?>?Ni?>?Mn). Duttaphrynus melanostictus is similarly sensitive to these metals as other amphibian tadpoles.     

A decade of fluvial morphodynamics: relocation and restoration of the Inde River (North-Rhine Westphalia,Germany)

Background

Relocations and restorations do not only change the ecological passability and sediment continuity of a river but also its flow behavior and fluvial morphodynamics. Sediment transport processes and morphological development can be assessed with field measurements, also taking the transport of sediment-bounded contaminants as a tracer material for fluvial morphodynamics into account. The objective of this study was to determine the morphological development of the Inde River (a tributary of the Rur River in North-Rhine Westphalia, Germany) towards its pre-defined guiding principle after a relocation and restoration in 2005 AD.

Methods

The fluvial morphodynamics of the Inde River were analyzed over a period of almost 15 years taking sediment samples, analyzing echo soundings of the river’s bathymetry and determining the heavy metal content of the sediment as a tracer material for the morphological development.

Results

The results show that the relocation and restoration of the Inde River initiates new hydrodynamic processes, which cause morphological changes of the river widths, meander belts and channel patterns. The riverbed of the new Inde River has incised into the ground due to massive erosion, which has led to increased fine sediment transport in the downstream direction. The reasons for and consequences of this fine sediment transport are discussed and correlated to the sediment continuity of a river.

Conclusions

Overall, the new Inde River has reached its goal of being a natural river as a consequence of the relocation and restoration and has adapted its new conditions towards a dynamic morphological equilibrium.

     

A new ecotoxicological test method for genetically modified plants and other stressors in soil with the black fungus gnat <Emphasis Type="Italic">Bradysia impatiens</Emphasis> (Diptera): current status of test development and dietary effects of azadirachtin on larval development and emergence rate

Background

Few suitable and standardized test methods are currently available to test the effects of genetically modified plants (GMP) on non-target organisms. To fill this gap and improve ecotoxicological testing for GMP, we developed a new soil ecotoxicological test method using sciarid larvae as test organisms.

Results

Bradysia impatiens was identified as a candidate species. Species of the genus Bradysia occur in high numbers in European agroecosystems and B. impatiens can be reared in the laboratory in continuous culture. A functional basic test design was successfully developed. Newly hatched larvae were used as the initial life stage to cover most of the life cycle of the species during the test. Azadirachtin was identified as a suitable reference substance. In several tests, the effects of this substance on development time and emergence rate varied for different temperatures and test substrates. The toxicity was higher at 25 °C compared to 20 °C and in tropical artificial soil compared to coconut fiber substrate.

Conclusions and outlook

Results suggest that the developed test system is suitable to enter a full standardization process, e.g., via the Organisation for Economic Co-operation and Development. Such a standardization would not only assist the risk assessment of GMP, but could include other stressors such as systemic pesticides or veterinary pharmaceuticals reaching the soil, e.g., via spreading manure. The use of sciarid flies as test organisms supports recommendations of EFSA, which stressed the ecological role of flies and encouraged including Diptera into test batteries.

     

Eiseniella tetraedra (Savigny, 1826) (Oligochaeta: Lumbricidae) as a bioindicator of heavy metals

The objective of this study was to assess the potential of the earthworm Eiseniella tetraedra (Savigny, 1826) as a bioindicator for cadmium (Cd) and lead (Pb) exposure. The importance of earthworms in metal pollution monitoring is widely recognized in terrestrial ecosystems. In this study, the levels of Cd and Pb in soils and earthworm tissues were studied at two locations, Polur Falls and a riverside area located in Abali, in the Elburz Mountains in Iran. At both locations the concentration of Cd and Pb in earthworms was higher than in the surrounding soils and a significant difference was found between the two stations, the latter probably attributable to the (1) amount of pesticides that are used for crop treatment in Abali and (2) presence there of clay, which is known to be rich in Cd. Data indicate that E. tetraedra is an efficient bioaccumulator of Cd and Pb and might act thus serve as a bioindicator of exposure.     

Influence of fertilizer and sewage sludge compost on yield and heavy metal accumulation by lettuce grown in urban soils

Previous research has demonstrated that many urban soils are enriched in Pb, Cd and Zn. Culture of vegetable crops in these soils could allow transfer of potentially toxic metals to foods. Tanya lettuce (Lactuca sativa L.) was grown in pots of five urban garden soils and one control agricultural soil to assess the effect of urban-soil metal enrichment, and the effect of soil amendments, on heavy metal uptake by garden vegetables. The amendments included NPK fertilizer, limestone, Ca(H₂PO₄)₂, and two rates of limed sewage sludge compost. Soil Cd ranged from 0.08 to 9.6 mg kg^–1; soil Zn from 38 to 3490 mg kg^–1; and soil Pb from 12 to 5210 mg kg^–1. Lettuce yield on the urban garden soils was as great as or greater than that on the control soil. Lettuce Cd, Zn and Pb concentrations increased from 0.65, 23, and 2.2 mg kg^–1 dry matter in the control soil to as high as 3.53, 422 and 37.0 mg kg^–1 on the metal-rich urban garden soils. Adding limestone or limed sewage sludge compost raised soil pH and significantly reduced lettuce Cd and Zn, while phosphate fertilizer lowered soil pH and had little effect on Zn but increased Cd concentration in lettuce. Urban garden soils caused a significant increase in lettuce leaf Pb concentration, especially on the highest Pb soil. Adding NPK fertilizer, phosphate, or sludge compost to two high Pb soils lowered lettuce Pb concentration, but adding limestone generally did not. On normally fertilized soils, Pb uptake by lettuce was not exceptionally high until soil Pb substantially exceeded 500 mg kg^–1. Comparing garden vegetables and soil as potential sources of Pb risk to children, it is clear that the risk is greater through ingestion of soil or dust than through ingestion of garden vegetables grown on the soil. Urban dwellers should obtain soil metal analyses before selecting garden locations to reduce Pb risk to their children.     

Wasserrahmenrichtlinie — Fortschritte und Defizite

Background

The water protection policy of the European Union sits on new footings since the end of 2000: The Water FrameworkDirective (WFD). By replacing, merging and renewing all parts of the European water protection policy from the 1970s, the WFD provides a consistent, transparent and comprehensive concept of what water management should be in the Europe of the coming decades. The new directive is aimed at a holistic approach towards integrated water protection. It sets ambitious high-quality goals to achieve a good status for European lakes and rivers primarily in ecological terms, gives details about the essential processes as well as instruments, and includes everything into a strict time schedule.

Aim

This article adresses progress and shortcomings at the implementation of the WFD in general and with reference to two selected case studies (Rivers Elbe and Upper Danube).

Results and Discussion

After introducing the WFD, its aims and exceptions, a policy summary and background document ‘Environmental objectives und the Water Framework Directive’ and the use of Environmental Quality Standards (EQS) for single ‘priority substances’ as well as ‘hazardous priority components’ is discussed. The initial characterization undertaken by the German states revealed that only about 14% of all surface waters are considered to meet the WFD objectives by the year of 2015. Approximately 60% of the water bodies assessed are at risk of failing the WFD objectives, if not systematic efforts are made to improve the quality. Screenings of sources and paths of exposure for ‘priority substances’ and ‘priority hazardous substances’ according WFD identified one distinct pollution source for surface waters: ‘Historical pollution from sediments’. Because of industrial emissions in the past several river catchment areas are expected to fail the standards demanded by the WFD, due to a risk of remobilization of contaminants from sediments. This holds true for the Rhine river with high loads of hexachlorobenzene (HCB) as well as for Elbe river, where contaminated sediments can be a severe problem. Therefore, integration of sediments into the holistic river basin management approach and their consideration within the ‘programmes of measures’ scheduled for 2009 is highly recommended. At present, a comprehensive weight-of-evidence study verifies whether the observed fish decline at the Upper Danube. River is caused by ecotoxicological hazard potentials of contaminated sediments.

Outlook

Combined investigations of sediment contamination and mobility as well as acute and mechanism specific biotests in effect directed analyses/weight-of-evidence studies show grent potential for the assessment of chemically polluted rivers and should be included into the ‘programmes of measures’ within future management concepts.

     

Direct and indirect effects of pesticides on a benthic grazer during its life cycle

Background

Macroinvertebrates in aquatic ecosystems are repeatedly exposed to pesticides during their life cycle. Effects of consecutive exposure during different life stages and possible synergistic effects are not addressed in the standardized hazard assessment. The present study investigated two environmentally relevant exposure scenarios in batch (microcosm) and artificial indoor stream (mesocosm) experiments using the larvae of the mayfly Rhithrogena semicolorata (grazer) and natural aufwuchs. Grazers were analysed regarding growth, physiological condition, and drift behaviour, while the aufwuchs was analysed in terms of biomass using the particulate organic carbon as well as the chlorophyll a content. The aim was to reveal direct and indirect effects of an herbicide exposure during autumn on juvenile grazers and an insecticide exposure during spring on semi-juvenile grazers.

Results

Direct and indirect effects were found in both exposure scenarios at environmentally relevant concentrations. In the herbicide exposure scenario with terbutryn, clear direct effects on the aufwuchs community with a LOEC of 0.38 µg L^?1 were found. Effect levels of grazers due to indirect effects were equal, with the overnight drift being the most sensitive grazer endpoint. In the insecticide exposure scenario, clear lethal and sub lethal effects of lambda-cyhalothrin were evident. Derived LC₅₀ values for the artificial indoor stream and batch experiment were 2.42 µg g^?1 OC (69 days) and 1.2 µg g^?1 OC (28 days), respectively. Sub lethal effects in terms of increased drift as well-reduced growth and triglyceride levels were found at concentrations of 1.4 and 0.09 µg g^?1 OC (LOECs). These results were confirmed by the batch experiment, which revealed effect values in the similar range. Finally, a clear indirect effect of the insecticide on the aufwuchs was evident in the batch experiment with an LOEC at 0.9 µg g^?1 OC.

Conclusion

Toxicity Exposure Ratios calculated with the derived effect values indicate a risk for the investigated grazer by both pesticides. Moreover, observed indirect effects during the herbicide exposure seem to be able to affect the grazers during a second exposure with an insecticide, due to reduced physiological conditions. We suggest further research with time-shifted exposure scenarios to gain a better understanding of the complex interactions of pesticides with the life cycle and the food webs of macroinvertebrates.

     

Ecotoxicological risks of the abandoned F–Ba–Pb–Zn mining area of Osor (Spain)

Due to its potential toxic properties, metal mobilization is of major concern in areas surrounding Pb–Zn mines. In the present study, metal contents and toxicity of soils, aqueous extracts from soils and mine drainage waters from an abandoned F–Ba–Pb–Zn mining area in Osor (Girona, NE Spain) were evaluated through chemical extractions and ecotoxicity bioassays. Toxicity assessment in the terrestrial compartment included lethal and sublethal endpoints on earthworms Eisenia fetida, arthropods Folsomia candida and several plant species, whereas aquatic tests involved bacteria Vibrio fischeri, microalgae Raphidocelis subcapitata and crustaceans Daphnia magna. Total concentrations of Ba (250–5110 mg kg^?1), Pb (940 to >5000 mg kg^?1) and Zn (2370–11,300 mg kg^?1) in soils exceeded intervention values to protect human health. Risks for the aquatic compartment were identified in the release of drainage waters and in the potential leaching and runoff of metals from contaminated soils, with Cd (1.98–9.15 µg L^?1), Pb (2.11–326 µg L^?1) and Zn (280–2900 µg L^?1) concentrations in filtered water samples surpassing US EPA Water Quality Criteria (2016a, b). Terrestrial ecotoxicity tests were in accordance with metal quantifications and identified the most polluted soil as the most toxic. Avoidance and reproduction tests with earthworms showed the highest sensitivity to metal contamination. Aquatic bioassays performed in aqueous extracts from soils confirmed the results from terrestrial tests and also detected toxic effects caused by the mine drainage waters. Algal growth inhibition was the most sensitive aquatic endpoint. In view of the results, the application of a containment or remediative procedure in the area is encouraged.     

Heavy metal speciation,leaching and toxicity status of a tropical rain-fed river Damodar,India

Speciations of metals were assessed in a tropical rain-fed river, flowing through the highly economically important part of the India. The pattern of distribution of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) were evaluated in water and sediment along with mineralogical characterization, changes with different water quality parameters and their respective health hazard to the local population along the Damodar River basin during pre-monsoon and post-monsoon seasons. The outcome of the speciation analysis using MINTEQ indicated that free metal ions, carbonate, chloride and sulfate ions were predominantly in anionic inorganic fractions, while in cationic inorganic fractions metal loads were negligible. Metals loads were higher in sediment phase than in the aqueous phase. The estimated values of I_geo in river sediment during both the seasons showed that most of the metals were found in the I_geo class 0–1 which represents unpolluted to moderately polluted sediment status. The result of partition coefficient indicated the strong retention capability of Cr, Pb, Co and Mn, while Cd, Zn, Cu and Ni have resilient mobility capacity. The mineralogical analysis of sediment samples indicated that in Damodar River, quartz, kaolinite and calcite minerals were dominantly present. The hazard index values of Cd, Co and Cr were >?1 in river water, which suggested potential health risk for the children. A combination of pragmatic, computational and statistical relationship between ionic species and fractions of metals represented a strong persuasion for identifying the alikeness among the different sites of the river.     

Metal accumulation risks in regularly flooded and non-flooded parts of floodplains of the River Rhine: Extractability and exposure through the food chain

Ecotoxicological risks of sediment contamination in floodplains are supposed to be highest in the regularly flooded parts. Therefore, in risk assessments, the non-flooded parts are neglected or considered to be reference areas. We investigated the metal extractability and levels in important food sources for vertebrates, viz. grass shoots and earthworms, in flooded as well as non-flooded parts and compared these with total metal concentrations. A comparison of these areas in the moderately polluted ‘Afferdensche en Deestsche Waarden’ floodplains along the River Rhine showed that total Zn, Pb, and Cd concentrations were highest in the regularly flooded parts. However, CaCl₂-extractable Zn concentrations were highest in non-flooded areas, and those of Pb and Cd were equal in both areas. Total Cu concentrations were not significantly different between the two areas, but CaCl₂-extractable Cu concentrations were highest in the regularly flooded areas. The metal concentrations in grass shoots of non-flooded areas were equal to (Zn, Cu, Cd) or higher than (Pb) those in regularly flooded areas. Zn concentrations in earthworms in regularly flooded areas were higher, but concentrations of Cu, Pb, and Cd were not. Ecotoxicological risk assessments require analysis of the total and potentially bioavailable metal concentrations in soils as well as concentrations in biota. This study shows that the less contaminated non-flooded areas in moderately polluted floodplains cannot be neglected in metal accumulation studies and cannot be used as pristine reference areas.     

Elbehochwasser 2002 — Ein Rückblick

Objective

Flood sediments were investigated due to the extreme flood situation around Dresden in August 2002

Method

The samples have been analyzed by screening inorganic and organic pollutants.

Results

It was observed that As, Pb, Cd, Zn, Cu, B and other heavy metals as well as DDT, PCB and Benzo [a] pyren were significantly enriched.

Conclusion

Depending on geogenic and anthropogenic impacts, the spatial distribution of these contaminants was different. Organic compounds were dislocated down stream from Czech Republic along the Elbe River. Because of the old ore mining, samples near the Mulde and Wei\eritz Rivers showed high metal pollution.

Perspective

More detailed and systematic investigations should be undertaken in the Elbe and Mulde river systems.     

Comparative effects of five chelating agents on testicular toxicity in mice induced by acute exposure to cadmium

The aim of this study was to develop new antidotes for cadmium (Cd) since this metal is known to produce mammalian toxicity. N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), N-benzyl-D-glucamine dithiocarbamate (BGD), diethyldithiocarbamate (DDTC), 2,3-dimercaptopropanol (BAL), and ethylenediamine-tetraacetic acid (EDTA) were studied for their ability to inhibit the adverse effects induced by Cd on mouse testes. The parameters examined included concentrations of Cd, calcium (Ca), iron (Fe), and zinc (Zn) in testes, lipid peroxidation (LPO) levels in testes, lactate dehydrogenase (LDH) activity in serum and reproductive ability of male mice. Mice injected intraperitoneally (ip) with CdCl₂ (2.5?mgCd?kg^?1) after 30?min or 24?h, were then injected ip with chelating agents (400?µmol?kg^?1). Cd increased the concentrations of testicular Ca, Cd, Fe, Zn, and LPO levels as well as the activity of LDH in serum. HBGD and BGD effectively prevented the increase in above indices, and improved the reproductive ability weakened by exposure to Cd. The results suggested that HBGD and BGD are more effective detoxificants in the case of testicular toxicity in mice induced by acute exposure to Cd.     

(Persistent) Organic pollutants in Germany: results from a pilot study within the 2015 moss survey

Background

Since 1990, every 5 years, moss sampling is conducted within the European moss monitoring programme to assess the atmospheric deposition of airborne pollutants. Besides many other countries, Germany takes regularly part at these evaluations. Within the European moss monitoring 2015, more than 400 moss samples across Germany were taken according to a harmonized methodology for the assessment heavy metal and nitrogen input. In a pilot programme, eight of these sites were chosen for additional investigations on a broad range of organic contaminants to evaluate their accumulation in moss and thereby their presence in atmospheric deposition in Germany. Target compound classes comprised polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzodioxins and –furans (PCDD/F), dioxin-like and non-dioxin-like polychlorinated biphenyls (dl-PCB, ndl-PCB), polyfluorinated alkyl substances, classical flame retardants as well as emerging chlorinated and brominated flame retardants. In total, 120 target compounds were analysed. For some analytes, comparisons of accumulation in moss and tree leave samples were possible.

Results

Except for certain flame retardants, PFAS, and ndl-PCB, substances of all other compound classes could be quantified in moss samples of all sites. Concentrations were highest for PAH (40–268 ng g^?1) followed by emerging flame retardants (0.5–7.7 ng g^?1), polybrominated diphenyl ethers (PBDE; 0.3–3.7 ng g^?1), hexabromocyclododecane (HBCD; 0.3–1.2 ng g^?1), dl-PCB (0.04–0.4 ng g^?1) and PCDD/F (0.008–0.06 ng g^?1).

Conclusions

Results show the widespread atmospheric distribution and deposition of organic contaminants across Germany as well as the suitability of moss as bioaccumulation monitor for most of these compound classes. Compared to nearby tree leaf samples, accumulation potential of moss appeared to be higher for pollutants of high octanol–air partition coefficient (K_OA) and octanol–water partition coefficient (K_OW).

     

Modelling of leachates from dolomitic mine tailings

The REDEQL.EPAK computer model was used to study speciation of Pb, Cd, Zn, and Ca in leachates from dolomitic Pb mine tailings. By allowing or disallowing precipitation of solids and equilibration of the modelled leachate with atmospheric C0₂, comparison of fresh and aged leachates was made. The effects of treatment of the tailings with phosphate containing fertilizer were studied through addition of P0₄ ^3– to the modelled solution. Equilibrium constants pertaining to metal ion-humic acid complexation were added to the thermodynamic data base of the model in order to study the effects of decaying plant material on tailings leachate.Initial leachate of the tailings is found to be supersaturated with Cd and Zn. Non-complexed (free) Cd²⁺ and Zn²⁺ is predicted to comprise most of the soluble form of these metals in the leachate; Pb is predicted to be present largely as PbCO₃ ion pair. Equilibration of the leachate with the atmosphere is predicted to lead to extensive precipitation of CdCO₃ and ZnSiO₃. Precipitation of Pb₅(PO₄)₃Cl is predicted at high PO₄ ^3– concentration and at low pH. Complexation by the humic acid is predicted to compete effectively with other ligands in the leachate for the metal ions. The results are compared with experimental findings.