A new ELISA for the quantification of equine procalcitonin in plasma as potential inflammation biomarker in horses.

In human medicine, procalcitonin (PCT) is a very common and well-established biomarker for sepsis. Even though sepsis is also a leading cause of death in foals and adult horses, up to now, no data about the role of equine PCT in septic horses has been available. Based on monoclonal antibodies targeted against human PCT, we report here the development of a sandwich ELISA for the quantification of equine PCT in equine plasma samples. The ELISA was characterized for intra- and interassay variance and a working range from 25 to 1,000 ng mL(-1) was defined as within this range; both intra- and interassay variances were below 15 %. The target recovery ranged between 73 and 106 %. The ELISA was used to determine the equine PCT concentration in 24 healthy and 5 septic horses to show the potential for clinical evaluation of equine PCT. Significantly different (P = 0.0006) mean equine PCT concentrations were found for the healthy control group and the sepsis group (47 and 8,450 ng mL(-1)).

Modelling passive sampling of hydrophilic compounds under time-variable aqueous concentrations.

Passive sampling is a crucial method for evaluating concentrations of hydrophilic organic compounds in the aquatic environment, but it is insufficiently understood to what extent passive samplers capture the intermittent emissions that frequently occur for this group of compounds. In the present study, silicone sheets and styrene-divinyl benzene-reversed phase sulfonated extraction disks with and without a polyethersulfone membrane were exposed under semi-field conditions in a 31 m3 flume at three different flow velocities. Natural processes and spiking/dilution measures caused aqueous concentrations to vary strongly with time. The data were analyzed using two analytical models that account for these time-variable concentrations: a sampling rate model and a diffusion model. The diffusion model generally gave a better fit of the data than the sampling rate model, but the difference in residual errors was quite small (median errors of 19 vs. 25% for silicone and 22 vs. 25% for SDB-RPS samplers). The sampling rate model was therefore adequate enough to evaluate the time-integrative capabilities of the samplers. Sampler performance was best for SDB-RPS samplers with a polyethersulfone membrane, despite the occurrence of lag times for some compounds (0.1 to 0.4 days). Sampling rates for this design also spanned a narrower range (80 to 110 mL/day) than SDB-RPS samplers without a membrane (100 to 660 mL/day). The effect of biofouling was similar for all compounds and was consistent with a biofouling layer thickness of 150 µm.

Tyre and road wear particles - A calculation of generation, transport and release to water and soil with special regard to German roads.

Tyre and road wear is one of the main emission sources of particulate plastics (microplastics). In this study, the emissions of tyre wear particles (TWP) which are annually generated on the German road network were calculated. Emissions are calculated by applying two different data sets of emission factors and the annual mileage for distinct vehicles and road types (urban roads, rural roads, highways). Environmental entry paths of tyre and road wear particles (TRWP) were considered including releases to ambient air, soils and surface waters. Road runoff treatment was taken into account differentiated into sewage systems in urban areas and at non-urban roads. This study identifies the soundest data available concerning emission factors, data on traffic and road systems as well as comprehensive information on road runoff treatment in Germany. Applying this data and assuming that 5% of the total emissions are 'fine' air-borne particles, the emissions of coarse 'non-airborne' particles are 75,200-98,400 t/a; . the transport to road banks and soils near roads is 57,300-65,400 t/a (66-76%) including runoff and drift; 8700-19,800 t/a (12-20%) are released to surface waters. Due to lack of data, degradation in soils and surface waters was not considered. Besides soils, urban wastewater treatment plants are expected to be an important sink of TRWP assuming that most of the particles are incorporated in the sewage sludge. Due to the application of sewage sludge as a fertilizer, 1400-2800 t/a TWP are currently deposited on agricultural areas. No reliable data was available to estimate the masses of TWP which are transported from freshwaters into the marine environment. Existing mitigation measures should be improved according to the principle of precaution by installation of road runoff treatment systems and retrofitting of existing plants regarding optimum fine particle retention.

Quantitative and qualitative evaluation of plastic particles in surface waters of the Western Black Sea.

Microplastic abundances have been studied intensively in the last years in marine and freshwater environments worldwide. Though several articles have been published about the Mediterranean Sea, only few studies about the Black Sea exist. The Black Sea drains into the Mediterranean Sea and may therefore significantly contribute to the Mediterranean marine pollution. So far, only very few articles have been published about micro-, meso- and macroplastic abundances in the Western Black Sea. In order to fill this knowledge gap and to decipher the number of plastics on the water surface, 12 samples were collected from surface waters with a neustonic net (mesh size 200 µm) in the Black Sea close to the Danube Delta and the Romanian shore. Organic matter was digested and plastic particles were isolated by density separation. The results of visual inspection, pyrolysis GC-MS (for microplastics) and ATR-FTIR (for mesoplastics >5 mm) revealed an average concentration of 7 plastic particles/m³, dominated by fibers (∼76%), followed by foils (∼13%) and fragments (∼11%). Only very few spherules were detected. The polymers polypropylene (PP) and polyethylene (PE) dominated which is in line with other studies analyzing surface waters from rivers in Western Europe as well as in China. Statistical analyses show that the plastic concentration close to the mouth of the Danube River was significantly higher than at four nearshore regions along the Romanian and Bulgarian coastline. This could be explained by plastic inputs from the Danube River into the western part of the Black Sea.

Sedimentary microplastic concentrations from the Romanian Danube River to the Black Sea.

A multitude of recent studies have detailed microplastic concentrations in aquatic and terrestrial environments, although questions remain over their ultimate fate. At present, few studies have detailed microplastic characteristics and abundance along a freshwater-marine interface, and considerable uncertainties remain over the modelled contribution of terrestrial and riverine microplastic to the world's oceans. In this article, for the first time, we detail sedimentary microplastic concentrations along a River-Sea transect from the lower reaches of a major continental river, the River Danube, through the Danube Delta, the Black Sea coast to the Romanian and Bulgarian inner shelf of the Black Sea. Our results indicate that isolated areas of the Danube Delta are still relatively pristine, with few microplastic particles in some of the sediments sampled.

Passive sampler phases for pesticides: evaluation of AttractSPE™ SDB-RPS and HLB versus Empore™ SDB-RPS.

In this study, three different passive sampling receiving phases were evaluated, with a main focus on the comparability of established styrene-divinylbenzene reversed phase sulfonated (SDB-RPS) sampling phase from Empore™ (E-RPS) and novel AttractSPE™ (A-RPS). Furthermore, AttractSPE™ hydrophilic-lipophilic balance (HLB) disks were tested. To support sampling phase selection for ongoing monitoring needs, it is important to have information on the characteristics of alternative phases. Three sets of passive samplers (days 1-7, days 8-14, and days 1-14) were exposed to a continuously exchanged mixture of creek and rainwater in a stream channel system under controlled conditions. The system was spiked with nine pesticides in two peak scenarios, with log KOW values ranging from approx. - 1 to 5. Three analytes were continuously spiked at a low concentration. All three sampling phases turned out to be suitable for the chosen analytes, and, in general, uptake rates were similar for all three materials, particularly for SDB-RPS phases. Exceptions concerned bentazon, where E-RPS sampled less than 20% compared with the other phases, and nicosulfuron, where HLB sampled noticeably more than both SDB-RPS phases. All three phases will work for environmental monitoring. They are very similar, but differences indicate one cannot just use literature calibration data and transfer these from one SDB phase to another, though for most compounds, it may work fine.

Microplastics and their possible sources: The example of Ofanto river in southeast Italy.

Monitoring studies have quantified microscopic plastic debris, so-called microplastics, in freshwater systems, including banks, surface waters and sediments. However, there is a lack of knowledge of freshwater and terrestrial environments. When microplastics are released in freshwater environments, they will be transported and will not remain stationary. Moreover, their transport from sink to source (land-based to river systems) may depend on several factors such as weather conditions and river hydrology. The present study aims to investigate the abundance and composition of microplastics in the most important river of Apulia Region (Southeast Italy) evaluating the main drivers and possible input sources of microplastic debris. The following work is the first study showing an Italian river context. For this research five sampling campaigns have been conducted west of the Ofanto river mouth. Microplastics were collected by three surface plankton nets fixed in the middle of the river in order to reduce the spatial and temporal variability. For each campaign, a total of six replicates were sampled during two time slots. Microplastic concentrations ranged from 0.9 ±â€¯0.4 p/m3 to 13 ±â€¯5 p/m3 showing comparable values to or greater than those ones reported in other studies. A statistically significant difference in the average microplastic concentrations in different campaigns of this study has been observed, suggesting thus a temporal variation in plastic abundances. These significant differences could be explained by the hydrology of the river that influences the particle concentration with its physical forces such as flow velocity, water level and seasonal variability. Microplastics were found at higher concentrations during wet periods indicating a land-based origin probably connected to waste produced by the surroundings agricultural areas. In fact, Spearman's correlation results show a strong positive statistically significant correlation between the concentration of microplastics and the water level (R = 0.8475, p < 0.0001).

Comparative assessment of microplastics in water and sediment of a large European river.

Aquatic ecosystems are globally contaminated with microplastics (MP). However, comparative data on MP levels in freshwater systems is still scarce. Therefore, the aim of this study is to quantify MP abundance in water and sediment of the German river Elbe using visual, spectroscopic (Fourier-transform infrared spectroscopy) and thermo analytical (pyrolysis gas chromatography mass spectrometry) methods. Samples from eleven German sites along the German part of the Elbe were collected, both in the water and sediment phase, in order to better understand MP sinks and transport mechanisms. MP concentrations differed between the water and sediment phase. Sediment concentrations (mean: 3,350,000 particles m-3, 125-5000 µm MP) were in average 600,000-fold higher than water concentrations (mean: 5.57 particles m-3, 150-5000 µm MP). The abundance varied between the sampling sites: In sediments, the abundance decreased in the course of the river while in water samples no such clear trend was observed. This may be explained by a barrage retaining sediments and limiting tidal influence in the upstream parts of the river. Particle shape differed site-specifically with one site having exceptionally high quantities of spheres, most probably due to industrial emissions of PS-DVB resin beads. Suspended MP consisted predominantly of polyethylene and polypropylene whereas sediments contained a higher diversity of polymer types. Determined MP concentrations correspond well to previous results from other European rivers. In a global context, MP levels in the Elbe relate to the lower (water) to middle section (sediment) of the global range of MP concentrations determined for rivers worldwide. This highlights that elevated MP levels are not only found in single countries or continents, but that MP pollution is an issue of global concern.

A new approach in separating microplastics from environmental samples based on their electrostatic behavior.

Numerous studies on microplastics (MPs; Ø < 5 mm) in the aquatic environment have been published, but knowledge about the occurrence and ecological risks of MPs is limited. This is in part because current data on the distribution of MPs are comparable only to a limited extent, due to the many different methods of investigation. In addition, sample preparation is often difficult such that standard procedures are lacking. The aim of this work was to simplify the preparation of different kinds of MP samples. Our method makes use of the electrostatic behavior of plastic particles to facilitate their separation from sample matter, with up to 99% of the original sample mass removed without any loss of MPs. To determine the efficacy of this approach, four different materials (quartz sand, freshwater suspended particulate matter, freshwater sediment, and beach sand) were spiked with MPs (size: 0.063-5 mm from the seven most common types of plastics, one bioplastic type, polyethylene fibers, and tire wear. A modified electrostatic metal/plastic separator was used to reduce the sample mass and concentrate the plastics based on their physical separation. The recovery achieved with this method was as high as nearly 100% for each type of material. The method was then tested on plastic particles of different shapes and types isolated from the Rhine River. These were successfully electroseparated from the four materials, which demonstrated the utility of this method. Its advantages include the simplified handling and preparation of different field samples as well as a much shorter processing time, because after the last separation step there is hardly any biological material remaining in the sample fraction.