Microplastics have been detected in lake environments globally, including in remote regions. Agricultural and populated areas are known to congregate several inputs and release pathways for microplastic. This study investigated microplastic (50–5000 µm) contamination in five Danish freshwater lakes with catchments dominated by arable land use. The concentrations in sediments (n = 3/site) and the zebra mussel, Dreissena polymorpha (n = 30/site), were calculated and compared with catchment characteristics and environmental parameters. Microplastic concentrations in sediment were relatively low (average 0.028 ± 0.017 items/g dry weight sediment) whilst only a single microplastic was found in the mussels (average 0.067 ± 0.249 items/10 individual). Hence, no relationship between the number of observed microplastics in sediment and mussels could be identified, nor could a relationship between concentration in sediment and environmental parameters. As all lakes studied received their water from moderate to heavily anthropogenically impacted catchments, it was expected that they would be sinks for microplastic with high bioavailability. Based on the results of the present study, D. polymorpha were found to not be contaminated by microplastics in the five study lakes. Thus, our results suggest that these mussels do not interact with microplastics at low concentrations. We speculate that the results on sediment and biota could be explained by several factors related to regional differences in plastic use, species characteristics, sampling size, and the fact that finding no microplastic is not always reported in the scientific literature. Thus, the paper provides insight into the dynamics between the catchment, lake, and biota in systems with low microplastic concentration. | publishedVersion

peer reviewed | Under arid and semi-arid conditions, direct application of phosphate rock (PR) as a source of phosphorus (P) for crop production is likely influenced by agricultural practices and soil properties. Different approaches could be used to improve the agronomic efficiency of low-grade PR over a wider range of soils and crops. In this study, biological, physical, and chemical treatments of low-grade Moroccan PR were investigated and compared through agronomic trials on faba bean grown under alkaline soil conditions. The physical treatment was based on blending PR with triple superphosphate (TSP) at 75:25 and 50:50 ratios, the biological treatments involved co-application of PR with compost at 50:50 ratio and phospho-compost elaborated from PR (20%), sewage sludge (46%), and wheat residues (34%), while the chemical treatment was obtained by a 30% acidulation of PR by phosphoric acid. Control treatments consisting of zero P application (control), PR alone, and TSP alone were considered to assess the effectiveness of the abovementioned techniques to improve PR agronomic efficiency. A pot experiment was conducted in sandy soil (Jorf Lasfar, central Morocco) for 60 days in a completely randomized design considering eight treatments. All treatments, except the control, were amended with 52 mg kg-1 of P from different PR-based fertilizers before sowing. At the flowering stage (60-day-old plants), results indicated that all PR treatments significantly improved plant growth, root nodulation, and nutrient uptake compared to the control. The relative agronomic efficiency of pretreated PR was significantly higher with phospho-compost treatment (86%) than the partially acidulated PR (78%) or the PR/TSP blend 50:50 (64%). Likewise, P uptake, P use efficiency, number of root nodules, and N uptake all were improved under PR treatments. Our finding revealed that the biological technique based on phospho-compost yielded better compared to chemical and physical treatments.

peer reviewed | Under arid and semi-arid conditions, direct application of phosphate rock (PR) as a source of phosphorus (P) for crop production is likely influenced by agricultural practices and soil properties. Different approaches could be used to improve the agronomic efficiency of low-grade PR over a wider range of soils and crops. In this study, biological, physical, and chemical treatments of low-grade Moroccan PR were investigated and compared through agronomic trials on faba bean grown under alkaline soil conditions. The physical treatment was based on blending PR with triple superphosphate (TSP) at 75:25 and 50:50 ratios, the biological treatments involved co-application of PR with compost at 50:50 ratio and phospho-compost elaborated from PR (20%), sewage sludge (46%), and wheat residues (34%), while the chemical treatment was obtained by a 30% acidulation of PR by phosphoric acid. Control treatments consisting of zero P application (control), PR alone, and TSP alone were considered to assess the effectiveness of the abovementioned techniques to improve PR agronomic efficiency. A pot experiment was conducted in sandy soil (Jorf Lasfar, central Morocco) for 60 days in a completely randomized design considering eight treatments. All treatments, except the control, were amended with 52 mg kg-1 of P from different PR-based fertilizers before sowing. At the flowering stage (60-day-old plants), results indicated that all PR treatments significantly improved plant growth, root nodulation, and nutrient uptake compared to the control. The relative agronomic efficiency of pretreated PR was significantly higher with phospho-compost treatment (86%) than the partially acidulated PR (78%) or the PR/TSP blend 50:50 (64%). Likewise, P uptake, P use efficiency, number of root nodules, and N uptake all were improved under PR treatments. Our finding revealed that the biological technique based on phospho-compost yielded better compared to chemical and physical treatments.

PR | IFPRI3; ISI; DCA; 1 Fostering Climate-Resilient and Sustainable Food Supply; 2 Promoting Healthy Diets and Nutrition for all; G Cross-cutting gender theme | DSGD

peer reviewed | Cadmium (Cd) is considered one of the heavy metals disturbing plant biophysiological functions. The potential role of phosphorus (P) nutrition in the attenuation of Cd effects on photosynthetic efficiency, plant growth, and cadmium uptake has been investigated in hydroponically grown tomato. Two P nutrition regimes (P15: 15 mg l-1; P30: 30 mg l-1) were assessed in the presence or absence of Cd (Cd0: 0 μM; Cd25: 25 μM of CdCl2). The results showed a positive effect of P30 concentration on leaf chlorophyll content and chlorophyll a fluorescence compared to P15 treatment under Cd stress (Cd25). The disturbance of electron transfer caused by Cd at K and I-steps of OJIP transient was attenuated with sufficient P supply. P30 enhanced the performance index of photosystem II and the efficiency of electron transfer to electron acceptor at PSI acceptor side. Besides, increased P concentration improved root growth parameters and biomass accumulation in the presence of Cd. It was found that root tissues accumulated more Cd than shoots and Cd translocation was reduced with increasing P concentration. Our results reveal that Cd-P interaction induced a cascade of physiological and chemical changes in plants. An optimal P nutrition can attenuate Cd stress on plant by the promotion of nitrogen and potassium uptake, which in return improved photosynthesis efficiency, enhanced biomass accumulation and distribution, and minimized Cd accumulation and translocation in plant tissues. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.

Embargo until November 4 2023 | Microplastic presence in benthic marine systems is a widely discussed topic. The influence of the natural matrix on microplastic distribution within the sedimentary matrix is often overlooked. Marine sediments from the western inner Oslofjord, Norway, were investigated for temporal trends, with a particular focus on the relationship between sediment grain-sizes and microplastic distribution. Density separation, optical microscopy and chemical validation were used to categorize microplastics. Microplastic concentrations ranged from 0.02 to 1.71 MPs g −1 dry weight (dw). Fibres were the most common (76%), followed by fragments and films (18%, 6%). Common polymers were polyesters (50%), polypropylene (18%), polymethylmethacrylate (9%), rayon and viscose (5%) and elastane (4%). Microplastics appear to accumulate preferentially according to their morphology and polymer type in certain sediment grain-sizes. Microplastics inputs to the Oslofjord appear to derive from a wastewater treatment plant in the vicinity. Although, the redistribution of microplastics within the fjord needs further investigation. | acceptedVersion

Benzene, toluene, ethylbenzene, xylenes, naphthalene and n-hexane evaporating from a thin oil film was measured for 30 min in a small-scale test system at 2 and 13 °C and the impact of physicochemical properties on airborne benzene with time after bulk oil release was studied. Linear mixed-effects models for airborne benzene in three time periods; first 5, first 15 and last 15 min of sampling, indicated that benzene content in fresh oil, oil group (condensate/light crude oil) and pour point were significant determinants explaining 63–73% of the total variance in the outcome variables. Oils with a high pour point evaporated considerably slower than oils with a low pour point. The mean air concentration of total volatile organic compounds was significatly higher at 13 °C (735 ppm) compared to 2 °C (386 ppm) immediately after release of oil, but at both temperatures the concentration rapidly declined. | acceptedVersion

The evaluation of the content of metals and metalloids in particulate matter (PM) and in atmospheric deposition in areas impacted by local industries is essential from an environmental and health risk perspective. In this study, the PM10 levels and atmospheric deposition fluxes of potentially toxic metals and metalloids were quantified at three urban sites of the Cantabrian region (northern Spain), located at different distances downwind of a Mn alloy plant. The content of Mn, V, Fe, Ni, Cu, Zn, As, Mo, Cd, Sb and Pb in PM10 and in the water-soluble and insoluble fractions of the deposition was determined by ICP-MS. Among the studied elements, the highest concentrations in PM10 and deposition rates were found for Mn, Fe, Zn and Pb, associated with the Mn alloy industry, and for Cu, related to non-exhaust traffic emissions. The levels of Mn, Fe, Zn and Pb in PM10 were higher in autumn, when the most frequent winds blow from the S-SW, whereas their highest deposition rates were found in winter and autumn, which are characterized by high monthly average precipitations. The water-soluble fraction of the atmospheric deposition of most metals increased with distance from the Mn alloy plant. The highest water-soluble fractions were found for Ni (72%), Zn (62%), Cu (60%) and Mn (49%). These results will be useful for the health risk assessment of the metal exposure associated with Mn alloy plants, as well as for the evaluation of the metal burden to soil, water and ecosystems related to this industrial activity. | This work was financially supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through the CTM2013-43904R Project. Ana Hernández-Pellón would like to thank the Ministry of Economy and Competitiveness (MINECO) for the FPI grant awarded, reference number BES-2014-068790.

A combined approach merging stable isotopes and fatty acids was applied to study anthropogenic pollution in the Río Negro estuary. Fatty acid markers of vegetal detritus indicated considerable allochthonous inputs at freshwater sites. Correlative evidence of diatom fatty acids, δ13C, chlorophyll and particulate organic matter suggested the importance of diatoms for the autochthonous organic matter production at the river mouth. Low δ15N values (~0�) and high fatty acid 18:1(n-7) concentrations in the suspended particulate matter, in combination with the peaks of coliforms and ammonium, indicated a strong impact of untreated sewage discharge. The 15N depletion was related to oxygen-limited ammonification processes and incorporation of 15N depleted ammonium to microorganisms. This work demonstrates that the combined use of lipid and isotopic markers can greatly increase our understanding of biogeochemical factors and pollutants influencing estuaries, and our findings highlight the urgent need for water management actions to reduce eutrophication.

Author's accepted version (postprint). | This is an Accepted Manuscript of an article published by Springer in Water, Air and Soil Pollution on 27/10/2018. | Available online: https://link.springer.com/article/10.1007/s11270-018-4013-9 | acceptedVersion