Life on bottles: Colonisation of macroplastics by freshwater biota

While rivers are known to be the main vectors of plastics to the sea, it seems surprising that studies on interactions (e.g. colonisation/entrapment and drift) between macroplastics and biota continue to remain largely neglected, notwithstanding they represent unexpected threats to freshwater biota and riverine habitats. To fill these gaps, here we focused on the colonisation of plastic bottles by freshwater biota. To do so, we collected 100 plastic bottles from the River Tiber in summer 2021. Overall, 95 bottles were colonised externally and 23 internally. Specifically, biota mainly occurred within and outside the bottles rather than plastic pieces and organic debris. Moreover, while bottles were externally covered mainly by vegetal organisms (i.e. macrophytes), they internally entrapped more animal organisms (i.e. invertebrates). The taxa most occurring within and outside the bottles belonged to pool and low water quality-associated taxa (e.g. Lemna sp., Gastropoda, and Diptera). In addition to biota and organic debris, plastic particles also occurred on bottles reporting the first observation of 'metaplastics' (i.e. plastics encrusted on bottles). Furthermore, we observed a significant positive correlation between the colonising taxa abundance and the bottle degree degradation. In this regard, we discussed how bottle buoyancy may change due to the organic matter on the bottle, affecting bottle sinking and transport along rivers. Our findings might be crucial for understanding the underrepresented topic of riverine plastics and their colonisation by biota, given that these plastics may act as vectors and cause biogeographical, environmental, and conservation issues to freshwater habitats.

Microplastic contamination in the sediments of Qarasu estuary in Gorgan Bay, south-east of Caspian Sea, Iran

Given the important ecological role of estuaries and implications of microplastics (MPs) in ecosystems, we assessed the occurrence, abundance, size, and polymer types of MPs present in the sediments of the Qarasu estuary in 2019. MPs were extracted from sediments by density separation, after which they were detected under a stereomicroscope and considered according to shape, size and color. Identification was implemented using Fourier-Transform Infrared Spectroscopy (FT-IR). The abundance and size of MPs in the samples ranged between 40 and 460 particles/kg and 200-5000 μm, respectively. The dominant shape of MPs was fiber (72%), followed by fragment (26%) and film (2%). Black and white were the most abundant colors with 48% and 29%, respectively. In total, 4 MPs polymers including polypropylene (33%), polyethylene (24%), polyamide (21%), and polystyrene (14%) were identified. Results from PCA showed that stations with a high abundance of microplastics had a significant correlation with the amount of clay.

Microplastics distribution and possible ingestion by fish in lacustrine waters (Lake Bracciano, Italy)

Understanding the spatial distribution patterns of microplastics (plastics < 5 mm) contributes to the assessment of sources and sinks of pollution thus providing information for the management of biota safety and overall ecosystem functionality. We chose a semi-closed study area, Lake Bracciano (Italy), to assess the environmental variability of contamination, focusing on the water compartment and the exposure of biota, specifically fish, by analysing the ingestion of microplastics. The focus of this study is to evaluate the concentration of microplastics in water (surface and column) across the lake and the ingestion of microplastics by two fish species of economic interest: Atherina boyeri and Coregonus lavaretus, inhabiting demersal and pelagic habitats respectively. Results show a surface contamination of 392,000 ± 417,000 items km^-2 and a column one of 0.76 ± 1.00 items m^-3. Fragments were the most abundant in surface while fibres in the column. Microplastics were found in C. lavaretus specimens, corresponding to contamination frequency of 5% and concentration of 0.15 items/fish. The main polymer found in water was polyethylene (81%); of minor percentages, there were various other polymers, including polystyrene and acrylic, which were also found in fish. As scientific literature provides few research where water and fish are simultaneously sampled, this investigation wants to contribute filling this knowledge gap by investigating for the first time a volcanic lake.

Spatial distribution of microplastics in volcanic lake water and sediments: Relationships with depth and sediment grain size

Microplastics (plastics <5 mm) are globally widespread pollutants of aquatic ecosystems. As microplastics contaminate both water and sediments, research on their spatial distribution in these different environmental matrices has increased. However, fresh waters are poorly studied and even less so are lentic ecosystems. To contribute filling this knowledge gap, this study analyses the distribution of microplastics in the water column and surface sediments of a volcanic lake, namely Lake Bracciano. Furthermore, it analyses in more detail the relationship between the concentration of microplastics in sediments, its grain size and the sampling depth (i.e. nearshore or deep). Water and sediment sampling was carried out in different sectors of the lake (northern, eastern, southern, western) using a plankton net and a van Veen grab sampler, respectively. Two sediment samples were collected at each station in order to analyse the abundance of microplastic and to perform grain size analysis. Results show a mean concentration of 2.4 items m^-3 in water and 42 items kg^-1 in sediments. The distribution of microplastics is uneven between the different sampling stations, with the northern sector being the most contaminated in both matrices. The chemical composition and shape of microplastics vary between water and sediment. In particular, polyethylene terephthalate and polyvinyl chloride are the most abundant polymers in water and sediments, respectively. Fibres are the main shape of microplastics in water while fragments are more abundant in sediments. In-depth analysis of sediment shows that sediments from deep stations are more contaminated than nearshore samples and have more fragment-shaped microplastics than fibre-shaped ones. Furthermore, there is a significant positive correlation between the concentration of microplastics and the abundance of silt, confirming data emerging from the scientific literature on marine and lotic ecosystems.

Is the weight of plastic litter correlated with vegetal wrack? A case study from a Central Italian beach

This study analyzes the occurrence and distribution of plastic litter and the entrapment of plastic by wrack beached on a natural reserve. Large microplastics (2.5 - 5 mm) were the most abundant plastic size category detected. The main color and shape were white and fragment, respectively. The plastics entrapped by egagropiles were mainly transparent fibers. We analyzed the correlation between the weights of plastic litter and vegetal wrack in two transects, selected for their different environmental characteristics. The transect closer to a breakwater showed a significant positive correlation between the weights of plastics and wrack, while the other transect suggested a casual pattern of plastic deposition on the beach. Further research is suggested to focus on the role of breakwaters in altering marine currents and enhancing plastic beaching.

Freshwater wild biota exposure to microplastics: A global perspective

Current understanding on the exposure of freshwater organisms to microplastics (plastics sized between 1 µm and 5 mm) has arisen mostly from laboratory experiments-often conducted under artificial circumstances and with unrealistic concentrations. In order to improve scientific links through real ecosystem exposure, we review field data on the exposure of free-living organisms to microplastics.We highlight that the main outputs provided by field research are an assessment of the occurrence and, at times, the quantification of microplastics in different animal taxa. Topics of investigation also include the causes of contamination and the development of biological monitoring tools. With regard to taxa, fish, mollusks, and arthropods are at the center of the research, but birds and amphibians are also investigated. The ingestion or occurrence of microplastics in organs and tissues, such as livers and muscles, are the main data obtained. Microorganisms are studied differently than other taxa, highlighting interesting aspects on the freshwater plastisphere, for example, related to the structure and functionality of communities. Many taxa, that is, mammals, reptiles, and plants, are still under-examined with regard to exposure to microplastics; this is surprising as they are generally endangered.As biota contamination is acknowledged, we contribute to an interdisciplinary scientific discussion aimed at a better assessment of knowledge gaps on methodology, impact assessment, and monitoring.

Evaluación de los cambios en una comunidad de líquenes epífitos después de 45 años, un caso de estudio en álamos blancos del norte de la península ibérica (jaca, Aragón)

Los líquenes epífitos se usan generalmente como bioindicadores, debido a que son organismos sésiles de crecimiento lento y las diferentes especies muestran un gran rango de sensibilidad ambiental. La mayoría de los estudios sobre líquenes epífitos se centran en utilizarlos como indicadores de las condiciones ambientales actuales, pero hay pocos analizando cambios temporales. La escasez de datos antiguos y la poca persistencia de los substratos, árboles en su mayoría, hacen que los estudios que incluyen una comparación temporal más o menos larga sean bastante raros. Sin embargo, en 1973 uno de nosotros (X. Llimona) describió la comunidad de líquenes de Populus alba de la parte urbana de Jaca, y esos árboles aún siguen vivos. El objetivo de este estudio es conocer la comunidad de líquenes de epífitos del 2018 y comparar con el estudio de 1973. La riqueza de especies disminuyó ligeramente durante estos 45 años. Sólo el 36% de las especies encontradas en 1973 persistían en 2018, aunque las persistentes se observaron con alta frecuencia en el muestreo de 2018. La sensibilidad ambiental de la comunidad de líquenes no cambió a lo largo de los años, así como, la localidad y sus alrededores no han cambiado de uso de suelo durante décadas. Los cambios en la composición de los líquenes entre ambos muestreos podrían explicarse por la sucesión autógena o limitación en la dispersión más que por filtraje ambiental. Nuestros datos sugieren que, en entornos estables, el ensamblaje de las comunidades de líquenes epífitos durante décadas depende de otros rasgos como la competencia y no de la sensibilidad ambiental de los líquenes.

[Supravalvular aortic stenosis. Report of 3 cases]

In the following article three cases of supravalvular aortic stenosis are presented: the first two cases refer to two brothers. The older, a 22-year-old man presenting with palpitations, underwent echocardiography and Doppler that showed an hour-glass supravalvular aortic stenosis with a peak gradient of 115 mmHg, associated with dilation of the left main coronary artery and stenosis of the left carotid artery at its origin. The patient's family was evaluated by echocardiography, and an 18-year-old brother was similarly found to have an hour-glass supravalvular aortic stenosis, graded mild to moderate (peak gradient 40 mmHg). Both cases are probably familiar forms of supravalvular aortic stenosis with normal facies and intelligence (autosomal dominant transmission). The elder brother, with severe stenosis, underwent surgical replacement of the ascending aorta. The third patient was a 23-year-old woman with a previous diagnosis of congenital aortic stenosis. Her characteristic elfic facies induced us to suspect the syndrome of Williams-Beuren; transthoracic and transesophageal echocardiographic examination showed an hour-glass supravalvular aortic stenosis with a peak gradient of 60 mmHg. Magnetic resonance imaging showed hypoplasia of the descending aorta and the iliac arteries. Since she was asymptomatic and presented only with a moderate gradient, the patient was not referred to surgical therapy. In this manuscript we present the three cases and review the histopathological, clinical, genetic, diagnostic and therapeutic aspects of this disease and its natural history.

[Ureteral jet in patients with benign prostatic hypertrophy: prognostic evaluation during single and combined therapy]

By color-Doppler ultrasound it's possible to visualize urine flow jet from ureter into the bladder. Aim of the study was to evaluate of ureteral jet in patients with benign prostatic hyperplasia before, during and after with one or two drugs medical therapy. Thirteen patients, aged 51-63 years, were studied; they were not affected by metabolic, hepatic, renal diseases and by prostate inflammation. Eco color Doppler p.w. (Toshiba SSA 270A) with a convex probe of 3.5 MHz was used. A transabdominal ultrasound study was performed, prostate volume measured and ureteral jet visualized before and along treatment (at six months interval) with Finasteride and at the end of treatment. Successively, in four patients, with relapse of prostatic synptomatology, a transabdominal ultrasound study was performed, before and along a treatment with Finasteride, 5 mg/die (Finastid, Neopharmed) and Terazosin hydrochloride, 5 mg/die (Teraprost, Malesci), and at the end of treatment.

[Acute changes in the hemodynamic profile and circulating levels of atrial natriuretic peptide induced by dobutamine in severe heart failure]

METHODS

Sixteen patients (15 males, 1 female; mean age 63 years, range 45-78) with severe heart failure (NYHA class III = 5; class IV = 11) secondary to ischemic heart disease (8), dilated cardiomyopathy (5) and valvular heart disease (3), were evaluated for eligibility to intermittent Dobutamine (D) treatment. As a part of this evaluation, they were submitted to an acute dose-ranging test with D, up to 10 micrograms/Kg/min under hemodynamic and electrocardiographic monitoring. By inclusion criteria, all patients had:-cardiac index (CI) < 2.2 L/min/m2;-pulmonary wedge pressure (WP) > 18 mmHg;-left ventricular ejection fraction (EF) < 30%. At each step of the procedure, hemodynamic measurements and blood sampling for atrial natriuretic peptide (ANP) concentration were performed.

RESULTS

Peak effect, defined as the dose corresponding to the maximum increase in CI, was reached at a mean of 7.8 +/- 0.5 micrograms/Kg/min. CI increased from 1.7 +/- 0.3 to 2.53 +/- 0.7 L/min/m2 (p < 0.001) and ANP decreased from 234 +/- 112 to 173 +/- 118 pg/ml (p < 0.001). Correspondingly, heart rate, stroke volume index and stroke work index increased, while right atrial pressure (RAP), mean pulmonary artery pressure (PAP), WP, systemic and pulmonary vascular resistance all significantly decreased. Mean arterial pressure was not affected. Changes in ANP concentration correlate significantly with changes in WP and in PAP (r = 0.65, p < 0.05 and r = 0.89, p < 0.001, respectively), but not with changes in RAP (r = 0.26, p = 0.34). Patients showing an increase > 40% in CI or a CI > or = 2.5 L/min/m2 at peak effect (responders) had significantly lower baseline PAP with respect to non-responders. Besides PAP, baseline ANP levels, end-systolic pressure/volume ratio and ejection fraction were also independent predictors of response. The test did not induce complex arrhythmias and was well tolerated in all patients.

CONCLUSIONS

Patients with severe heart failure retain the ability to respond to acute administration of D. with a significant improvement in their hemodynamic profile. Response to D. administration is predicted by lower baseline pulmonary pressure and ANP levels and a lesser degree of left ventricular dysfunction. Despite high baseline ANP concentration, a significant decrease is obtained which parallels the decrease in pulmonary artery and pulmonary wedge pressure, but is not related to changes in right atrial pressure. These findings suggest that changes in left ventricular performance induced by D. are the major determinants of the decrease in ANP concentration in this clinical setting.