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.

Purpose Climate warming can change the geographic distribution and intensity of the transmission of vector-borne diseases such as malaria. The transmitted parasites usually benefit from increased temperatures as both their reproduction and development are accelerated. Lower Saxony (northwestern Germany) has been a malaria region until the 1950s, and the vector species are still present throughout Germany. This gave reason to investigate whether a new autochthonous transmission could take place if the malaria pathogen was introduced again in Germany. Materials and methods The spatial distribution of potential temperature-driven malaria transmissions was investigated using the basic reproduction rate (R ₀) to model and geostatistically map areas at risk of an outbreak of tertian malaria based on measured (1961-1990, 1991-2007) and predicted (1991-2020, 2021-2050, 2051-2080) monthly mean air temperature data. Results From the computations, maps were derived showing that during the period 1961-1990, the seasonal transmission gate ranges from 0 to 4 months and then expands up to 5 months in the period 1991-2007. For the projection of future trends, the regional climate models REMO and WettReg were used each with two different scenarios (A1B and B1). Both modelling approaches resulted in prolonged seasonal transmission gates in the future, enabling malaria transmissions up to 6 months in the climate reference period 2051-2080 (REMO, scenario A1B). Discussion The presented risk prognosis is based on the R ₀ formula for the estimation of the reproduction of the malaria pathogen Plasmodium vivax. The presented model focuses on mean air temperatures; thus, other driving factors like the distribution of water bodies (breeding habitats) or population density are not integrated. Nevertheless, the modelling presented in this study can help identify areas at risk and initiate prevention. The described findings may also help in the investigation and assessment of related diseases caused by temperature-dependent vectors and pathogens, including those being dangerous for livestock as well, e.g. insect-borne bluetongue disease transmitted by culicoids.

INTRODUCTION: In this study, we provide strategies for detecting and quantifying the structural isomers of polyfluorinated di- and tri-alkyl surfactants (PFAS) by mass spectrometry (MS). We specifically investigate polyfluorinated dialkylated phosphate ester surfactants (x:2/y:2 diPAPS, (F(CF2) x CH2CH2O-P(O)(O)−-OCH2CH2(CF2) y F)) and their thioether analogues (x:2/y:2 S-diPAPS, F(CF2) x CH2CH2SCH2-C[CH2O)2P(O)(O)−]-CH2SCH2CH2(CF2) y F), which are used for industrial applications, such as oil- and water-repellent coatings on paper and board. DiPAPS have been found in human blood and are metabolised to the persistent perfluoroalkyl carboxylic acids (PFCA) in rats. MATERIALS AND METHODS: A microwave popcorn bag extract was analysed by ultrahigh-pressure liquid chromatography coupled to a negative electrospray ionisation-quadrupole time-of-flight MS. RESULTS AND DISCUSSION: The extract contained S-diPAPS, diPAPS and trialkylated (triPAPS) impurities. TriPAPS were also present in industrial and synthetic diPAPS standards, and were verified with an 8:2/8:2/8:2 triPAPS standard. The eight elemental compositions (m/z’s) of diPAPS in the extract represent 19 precursor ion structures, and the six S-diPAPS m/z’s represent at least 13 structures. The diPAPS had [M-H]− precursor ions of m/z 789, 889,…1,489 and the S-diPAPS of m/z 921, 1,021,…1,421, corresponding to fluorinated chains from C6–18. Each m/z appeared as one to three chromatographic peaks of structural isomers, where, e.g. m/z 1,189 was present as 10:2/10:2, 8:2/12:2 and 6:2/14:2 diPAPS. The isomers formed different products ions, thus only half of the m/z 1,189 diPAPS concentration was measured with one precursor ion > product ion transition. CONCLUSION: In general, knowledge about structural isomers of poly-alkylated PFAS is needed for the estimation of types and amounts of perfluorinated degradation products, such as PFCA from diPAPS.

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.

INTRODUCTION: A greenhouse experiment was conducted to determine if Cucurbita pepo ssp. pepo (pumpkin) root exudates could increase the uptake of polychlorinated biphenyls (PCBs) into plants. Contaminated soil was pre-treated with pumpkin root exudates by first growing pumpkins in the soil. Plants (pumpkins and weeds) were grown in the pre-treated (root exudate group) and non-treated (control group) contaminated soils. Seeds from five weed species collected from two contaminated sites were germinated in sufficient quantities (n ≥ 6) for three seedlings to be planted in two groups. DISCUSSION: Plants from both the control group and the root exudate group extracted a combined total of ∼1.2% PCBs from soil. Differences in root concentrations between groups were observed for Bidens cernua (beggar’s tick) and in total PCBs extracted into the roots for pumpkins. This is the first report of significant changes in the PCB phytoextraction ability of multiple plant species due to the presence of root exudates. In addition, slight differences were also observed for root and shoot concentrations and extractions by several other species, though these were not statistically different at α = 0.05. While the mechanism of phytoextraction is still unknown, this study indicates that the root exudates of C. pepo ssp. pepo can affect the uptake and transport of contaminants within specific plant species.

INTRODUCTION: This study aimed to analyze antioxidant responses and oxidative damage induced by two inorganic forms of arsenic (As; AsIII and AsV) in an estuarine polychaete species, Laeonereis acuta (Nereididae). The capacity of arsenic biotransformation was also evaluated through the methylation process considering the activity of a key enzyme involved in the metabolization process. MATERIALS AND METHODS: Worms were exposed to 50 μg (AsIII or AsV)/l during 2 or 7 days, plus a control group. Endpoints analyzed included concentration of reactive oxygen species (ROS), activities of antioxidant enzymes such as glutathione reductase (GR), total glutathione-S-transferase (GST), and omega isoform (GST Ω), glucose-6-phosphate deshydrogenase (G6PDH), levels of the antioxidant glutathione (GSH), and lipid peroxides concentration (TBARS). RESULTS AND DISCUSSION: Results showed: (1) GR inhibition after 2-day exposure to both As forms (p < 0.05); (2) GST Ω inhibition after 7-day exposure to AsIII paralleled by an increase in total GST activity (p < 0.05); (3) augmented G6PDH activity after 7-day exposure to both As forms (p < 0.05); (4) no differences in terms of ROS and TBARS; and (5) inhibition of GST Ω activity in AsIII exposed worms, which was concomitant with a lowering of mono- and dymethylated arsenic species. CONCLUSION: These results confirm the reactivity of some biochemical variables of L. acuta to As and indicates its importance as a sentinel species in estuarine regions with presence of arsenic.

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.

Introduction Inorganic ion concentrations in event-based wet-only precipitation samples collected during the south-west (SW) monsoon at an urban location in Western India, Ahmedabad between July 2000 and September 2002 were measured by Rastogi and Sarin (2007). Methods For the first time at a location in India, an advanced factor analysis model was retrospectively applied to the measured concentrations of ions (Rastogi and Sarin 2007) in precipitation for source apportionment. Positive matrix factorization resolved five factors, including crustal material, sea salt, nitrate/sulfate-rich factor, ammonium-rich factor, and free acidity. Results and discussion Amongst the model-resolved factors, crustal material was the highest contributor to the total dissolved solids (TDS) accounting for 44.1% on average. Potential source contribution function (PSCF) analysis identified source locations along the eastern coast of Somalia, Yemen, Oman, and the United Arab Emirates for this factor. Sea salt was the second highest contributor accounting for 29.8%. The potential source regions of this factor were also identified in the Arabian Sea and the southern Indian Ocean along the coast of Africa, and the Arabian Gulf. This study also examined the spatial relationships between the source locations of chemical species in precipitation and in ambient aerosol (resolved in an earlier study). Conclusions Crustal material was the highest contributor to TDS at the study location. Spatial relationships between aerosol and precipitation factor source regions suggested that below-cloud scavenging of aerosol particles was a likely contributor to the chemical species apportioned to various precipitation factors. Additionally, source types of chemical species in precipitation resolved in this study were qualitatively compared with those identified at other locations in India. The comparison showed that soil was an important contributor to the dissolved mass of chemical species in precipitation at all locations in India.

INTRODUCTION: To use biomarkers in monitoring programmes, potential confounding factors must be considered. In the clam Scrobicularia plana, the influence of size and salinity on biomarkers at different levels of biological organisation has been examined. MATERIAL AND METHODS: Biochemical (glutathione-S-transferase, lactate dehydrogenase, acetylcholinesterase, digestive enzymes, metallothionein), physiological (energy reserves) and behavioural (burrowing) responses were compared (a) in specimens of different sizes from the Loire estuary; (b) in specimens from the Belon estuary at two sites with salinities of 30.1 or 11.5. RESULTS: Amongst the biomarkers able to reveal pollution effects, several are influenced by the size of the clams (Ag, Cu, Ni and glycogen concentrations, GST and AChE activities, condition indices). Salinity differences induced variations of the same order of magnitude (GST, AChE) or even higher (lactate dehydrogenase, digestive enzymes in the crystalline style) than contamination-induced variations. In burrowing tests, the number of burrowed specimens was similar at both salinities after an experiment time <3 h. CONCLUSIONS: Size is a factor necessarily but easily controlled. Because the weight may be different in clams of identical size, correction factors may be used to minimise the influence of weight changes on biomarkers. A correction factor taking into account salinity levels can also be used. The protein concentrations in the clams did not differ with salinity, a very favourable outcome since all enzyme activities are classically expressed by reference to total protein concentrations. For burrowing tests, the number of burrowed specimens at a particular time is an endpoint that is preferable to measures of burrowing speed.