Background aim and scope The objective of the study was to determine the effects of ca. 35 years of pesticide contamination (pesticide dump--PD) of Lake Szeląg Wielki (located in the north-eastern Poland) on changes in the microbial communities of aquatic ecosystems. In the years 2008-2009, analyses were carried out for seasonal changes in the quantity and composition of bacterioplankton in the lake examined, which is of high significance to the tourism and fishing industries and is located in the vicinity of an area subjected to reclamation after a pesticide dump. Methods Bacterioplankton composition was assayed by fluorescence in situ hybridisation technique for the contribution of major groups of the Bacteria domain: ά-, β- and γ-Proteobacteria, Cytophaga-Flavobacterium and Actinobacteria as well as bacteria capable of degrading pesticides in an aquatic environment--Pseudomonas spp. Seasonal patterns of the total number of bacteria were determined by direct counting of 4′,6-diamidino-2-phenylindole (DAPI)-stained cells. Results The percentage of the detected Eubacteria (EUB 338 probe) relative to all the DAPI-stained bacteria in Lake Szeląg Wielki ranged from 46% to 63%. Bacteria capable of degrading pesticides in an aquatic environment--Pseudomonas spp.--were identified with a highly specific probe PEA 998. The highest mean values of this parameter reached 5.1%. In the spring, Pseudomonas spp. bacteria accounted for up to 80% of all Gamma-Proteobacteria microbes. Conclusion The study showed that the qualitative and quantitative changes in the bacterioplankton of the lake can be characterised by tendencies which are typical of a eutrophic water reservoir. However, a higher contribution of microorganisms capable of degrading sparingly degradable, toxic compounds and pesticides was determined in bacterioplankton from the PD-contaminated lake, as compared to microbial communities of a lake not contaminated with pesticides.

INTRODUCTION: Effluent organic matter from biological wastewater treatment plants is composed of degradation products and soluble microbial products (SMP). Protein, polysaccharide, humic acid, and DNA were major biomolecules of SMP. Little is known about the effects of SMP as microbially derived precursors on disinfection byproduct formation and speciation in biologically treated wastewater. In addition, there has never been any attempt to directly chlorinate the major biomolecules of SMP. MATERIALS AND METHODS: In this study, model compounds (bovine serum albumin, starch, DNA, and humic acid) and SMP collected from a sequencing batch reactor (SBR) were chlorinated to verify the trihalomethane and haloacetic acid species that were produced from them. RESULTS AND DISCUSSION: The results showed that chloroform, dichlorobromomethane, dichloroacetic acid, and trichloroacetic acid were generated from the chlorination of SMP in the SBR, and there was a close relationship between the species predicted from the model chemical compounds and those obtained from the SMP.

INTRODUCTION: Through leaching experiments and simulated rainfall experiments, characteristics of vertical leaching of exogenous rare earth elements (REEs) and phosphorus (P) and their losses with surface runoff during simulated rainfall in different types of soils (terra nera soil, cinnamon soil, red soil, loess soil, and purple soil) were investigated. RESULTS AND ANALYSES: Results of the leaching experiments showed that vertical transports of REEs and P were relatively low, with transport depths less than 6 cm. The vertical leaching rates of REEs and P in the different soils followed the order of purple soil > terra nera soil > red soil > cinnamon soil > loess soil. Results of the simulated rainfall experiments (83 mm h⁻¹) revealed that more than 92% of REEs and P transported with soil particles in runoff. CONCLUSION: The loss rates of REEs and P in surface runoff in the different soil types were in the order of loess soil > terra nera soil > cinnamon soil > red soil > purple soil. The total amounts of losses of REEs and P in runoff were significantly correlated.

Introduction Balya and its associated villages which is a town of the Balikesir region of Turkey have very rich zinc, lead, and manganese mines. These mines have been operating since the thirteenth century and now there is heavy metal contamination in both the soil and natural waters in these areas. Materials and methods Soils were collected from Sarı su, Enverpaşa, and Hastanetepe which are in Balya town and Kadıköy, Kaşıkcı, Müstecap, Patlak, Çakallar, and Bengiler which are the villages near Balya and the mine areas. Nine trace analytes (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) were determined using an acid extraction procedure as well as from PBET in vitro gastro-intestinal experiments using ICP-OES. Results and discussion The results showed that high As, Ba, Pb, Zn, and Cd concentrations were found in these soils. The amounts ingested by pica behavior of children at the rate of 10 g day⁻¹ are calculated using the results of in vitro intestinal bio-accessibility experiments. Conclusion The results showed that the amount of As, Pb, Ba, and Cd levels ingested by pica behavior are substantially higher than tolerable daily intake values in most of the soils. When normal ingestion is taken into account, the tolerable daily limits are only exceeded for one element (Pb) and even then, only at two sites.

Purpose α-Hexachlorocyclohexane (HCH), β-HCH, and lindane (γ-HCH) were listed as persistent organic pollutants by the Stockholm Convention in 2009 and hence must be phased out and their wastes/stockpiles eliminated. At the last operating lindane manufacturing unit, we conducted a preliminary evaluation of HCH contamination levels in soil and water samples collected around the production area and the vicinity of a major dumpsite to inform the design of processes for an appropriate implementation of the Convention. Methods Soil and water samples on and around the production site and a major waste dumpsite were measured for HCH levels. Results All soil samples taken at the lindane production facility and dumpsite and in their vicinity were contaminated with an isomer pattern characteristic of HCH production waste. At the dumpsite surface samples contained up to 450 g kg⁻¹ Σ HCH suggesting that the waste HCH isomers were simply dumped at this location. Ground water in the vicinity and river water was found to be contaminated with 0.2 to 0.4 mg l⁻¹ of HCH waste isomers. The total quantity of deposited HCH wastes from the lindane production unit was estimated at between 36,000 and 54,000 t. Conclusions The contamination levels in ground and river water suggest significant run-off from the dumped HCH wastes and contamination of drinking water resources. The extent of dumping urgently needs to be assessed regarding the risks to human and ecosystem health. A plan for securing the waste isomers needs to be developed and implemented together with a plan for their final elimination. As part of the assessment, any polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) generated during HCH recycling operations need to be monitored.

Background Environmental agencies have to take measures to either reduce discharges and emissions of nitrate or to remediate nitrate-polluted water bodies where the nitrate concentrations exceed threshold values. Isotope data can support the identification of nitrate pollution sources and natural attenuation processes of nitrate. Review This review article gives an overview of the information available to date regarding nitrate source apportionment in surface waters with the ambition to help improving future studies. Different isotope approaches in combination with physicochemical and hydrological data can successfully be used in source apportionment studies. A sampling strategy needs to be developed based on possible nitrate sources, hydrology and land use. Transformations, transport and mixing processes should also be considered as they can change the isotope composition of the original nitrate source. Conclusion Nitrate isotope data interpreted in combination with hydrological and chemical data provide valuable information on the nitrate pollution sources and on the processes nitrate has undergone during its retention and transport in the watershed. This information is useful for the development of an appropriate water management policy.

Background and purpose Surfactant-assisted soil washing and photocatalysis are well-known remediation processes of environmental concern. The application of photocatalysis to treat soil washing extracts containing 4-methylphenol, 4-ethylphenol and 4-tert-butylphenol in the presence of nonionic (C₁₂E₈ and C₁₂E₂₃) and anionic (SDS) surfactants and some of their binary mixtures was investigated in this work by studying the pollutants degradation in the presence of TiO₂ dispersions irradiated with simulated solar light. Materials and methods Clean soil samples were spiked with the investigated alkylphenols. Aqueous solutions of the chosen surfactants were placed in contact for some hours with the spiked soil samples in a rotatory mixer. The pollutants recoveries were evaluated via HPLC analysis. Photocatalytic experiments were performed in solarbox on aqueous solutions and on aqueous surfactant solutions containing the pollutants. Results The pollutants removal from the soil was proven effective using the examined surfactant solutions. The photocatalytic treatment of the wastes was faster using Brij 35, but also SDS and C₁₂E₈-SDS mixtures can be applied. After 2-5 h the complete pollutants abatement was obtained, depending on the surfactant chosen and on the amount of TiO₂ employed. On the contrary, the treatment of wastes containing C₁₂E₈ was an extremely slow process. Conclusions The photocatalytic approach can be applied to remove the examined aromatic pollutants from the washing wastes, confirming the viable coupling between this advanced oxidation method and the surfactant-based soil remediation treatments. Surfactant adsorption onto TiO₂ and micelles concentration play a dominant role.

BACKGROUND, AIM AND SCOPE: Seed treatments are widely used on cereals and other annual crops throughout Europe. Most of the formulated pesticide is found on the outside of the seed, the husk. Risk assessments of seed treatments are especially needed for granivorous mice living in the agricultural landscape e.g. for registration using the guidance for risk assessment for birds and mammals (EFSA 2009). The dehusking of seeds before consumption is a known behaviour of these mammals, but so far, no quantitative data on the reduction of exposure of seed treatments by dehusking were published. Therefore, we aimed at providing a first quantitative estimate of this behaviour-related exposure reduction for the wood mouse (Apodemus sylvaticus) with different seed types. MATERIALS AND METHODS: We evaluated the efficiency of dehusking behaviour of 20 wood mice captured in the wild for four different seeds (wheat, barley, maize and sunflower). One experimental setup used a fungicide seed treatment where the remaining seed husks of consumed seeds were analysed with a HPLC-MS/MS technique. In the second setup, we measured generic pigment present in a blank seed treatment formulation and determined the leftover pigment in the husks with a photometric technique. RESULTS: The exposure reduction was similar for the fungicide and the pigment design where the same seed types were studied. We could demonstrate exposure reductions ranging from around 60% for cereals to almost 100% for sunflower seeds as a result of the dehusking behaviour. DISCUSSION: Since exposure reduction was similar in both approaches, working with pigments would be a generic way to estimate the impact of dehusking behaviour on seed treatment exposure. This behaviour can result in a substantial exposure reduction and should, therefore, be considered in a seed-type specific way in the risk assessment of pesticide seed treatments. CONCLUSIONS: It is proposed to include a seed-specific dehusking factor in the calculations of estimated theoretical exposure of seed treatments for granivorous mice. The approach of accounting for a dehusking-related exposure reduction by field relevant wild mammal species seems a more promising way to advance the risk assessment instead of using generic species and neglecting behavioural traits. The pigment approach could be used to gather data for exposure reduction for other species and seed types. Its advantage is that it is harmless to the test species and comparatively cheap since no chemical analysis is involved. RECOMMENDATIONS AND PERSPECTIVES: Seed treatments are used for most of the cereal crops grown in Europe today. Their advantages usually include a lower application rate and the reduction of drift compared to a conventional spraying regime. However, there is a potential risk especially for granivorous mice, and its assessment is challenging in case of a high residue concentration on the dressed seeds. The concept of a dehusking factor in the risk assessment scheme for seed treatments for granivorous mice is a valid approach to account for the behavioural exposure reduction, and generic data could be easily generated also for other wild mammal species and other seed types, possibly analysing the pigment in commercial seed treatment formulations.

PURPOSE: The purpose this research is to investigate the interaction of Cr(VI) species, present as Cr₂O₇ ²⁻, at ambient temperature with brick clay pre-fired at different temperatures. METHODS: A multi-technique approach was used for this investigation. Experiments such as surface titrations, Langmuir and Freundlich adsorption isotherms, mass-firing temperature investigation, scanning electron microscopy, Fourier transform infrared spectra, X-ray fluorescence spectra, and X-ray diffraction were conducted in this investigation. RESULTS: Fired brick clay, which bears a negative charge according to surface titration measurements, shows affinity towards Cr(VI) species despite the negative charge of the source of Cr(VI). The Cr(VI)—brick clay heterogeneous system, which shows the strongest interaction with brick clay fired at 200°C, obeys both the Langmuir and the Freundlich adsorption isotherms with high regression coefficients. Investigation on surface charge, constituents of brick clay, acid treatment of clay particles, and the effect of firing temperature suggests that the reduction of Cr(VI) to Cr(III) by reducing agents present in brick clay makes a significant contribution for adsorption of chromium species followed by subsequent removal. Scanning electron microscopic images support the adsorption of chromium species, and further, many metal ions are released as a result of Cr(VI)—brick clay interaction according to X-ray fluorescence studies. CONCLUSION: It is concluded that fired brick clay shows strong adsorption capacity on Cr(VI), having the maximum interaction with brick clay fired at 200°C. It is proposed that this methodology be extended for treatment of effluents containing Cr(VI) species.

Purpose Industrial emissions can raise urban background levels of inhalable Mn particles in an order of magnitude above normal, eclipsing the contribution made by natural sources and traffic. Methods The source of such emissions can be identified using a multidisciplinary approach which integrates ICP-MS chemical analyses of PM₁₀ and PM₂.₅ samples with positive matrix factorization source apportionment modelling, scanning electron microscopy and meteorological data. Results We apply this methodology to data from Santander (N Spain), where morning Mn-bearing industrial contamination sourcing from the SW is returned towards the city by afternoon NE sea breezes. This wind direction reversal carries the industrial pollution plume inland, detectably raising urban background levels of MnPM₁₀ in the town of Torrelavega 20 km away. Industrially sourced daily urban background Mn levels at Santander reach >1,000 ng/m³, average >150 ng/m³. Conclusions We demonstrate the anomalous nature of such concentrations by comparing them with >2,500 PM₁₀ chemical analyses of ambient PM₁₀ from other sites in Spain which show how current background Mn levels in urban air typically average only 10 ng/m³, rising to 20-25 ng/m³ in city traffic sites. Daily levels of atmospheric Mn PM₁₀ only rarely exceed 50 ng/m³, usually during desert dust intrusions which, in extreme cases (such as Canary Islands “calima” events from Africa) can produce Mn concentrations of 100-125 ng/m³.