The new era hypothesis of coastal degradation: G(s) elements-gallium, gadolinium, and germanium.

Mining of precious metals contributes to environmental pollution, especially in coastal areas, and conventional treatment methods are not always effective in removing metal contaminants. Some of these metals, such as gadolinium, germanium and gallium, have caused increasing concern worldwide, as little is known about their current concentrations in the aquatic environment and their biological significance. Therefore, the aim of this study was to determine for the first time the variation of average G(s) concentrations (gallium, gadolinium and germanium) by month/season/site differences along the coast of Istanbul. The ecological risk index was calculated to assess the contamination of seawater and to serve as a diagnostic tool for the mitigation of water pollution. The average distribution G(s) in seawater was in the following order: Ga > Gd > Ge. In addition, the potential ecological risk in the sampling areas ranged from 68 to 1049. Of the three metals, Gd poses the highest ecological risk (grade III). In the spatial distribution of ecological risks, Gd mainly originated from discharges from wastewater treatment plants. Therefore, the sources of the anthropogenic Gd anomaly in wastewater should be identified, as this indicates the possibility of human exposure to potentially harmful anthropogenic compounds.

Potential Ecological Risk Assessment of Critical Raw Materials: Gallium, Gadolinium, and Germanium.

In recent years, the demand for critical raw materials such as gallium, gadolinium and germanium (G(s)) has steadily increased in various industries. However, treatment or recycling rates of these elements are extremely low, which can lead to environmental pollution. An assessment of the ecological risks was also not possible until now, as there were no calculated toxicity coefficients for G(s). In this study, a well-known method, the so-called potential ecological risk index (PERI), was used for the first time to calculate the toxicity coefficients of these elements using data from recent literature studies on G(s) elements. The toxicity coefficient of each of the three elements was determined as five (5). The results show that G(s) have the same toxicity coefficient as Cu and Pb and are higher than that of Cr. The ecological risk index results varied from 4 to 414, 0.98 to 25.98 and 2.50 to 284.64 for Ga, Gd and Ge, respectively. The results show that Ga and Ge pose high ecological risk while the Eri of Gd is low. The toxicity coefficients of these elements have been calculated for the first time in the literature and provide a practical use for calculating the potential ecological risk index.

Impact of coastal wastewater treatment plants on microplastic pollution in surface seawater and ecological risk assessment.

This study aims to understand the influence of wastewater treatment plant discharge on the microplastic status in the surface seawater of Istanbul. For this purpose, for the first time, the distribution, composition, and ecological risk of microplastics at nine sampling stations on the southern coast of Istanbul, Marmara, were investigated at monthly intervals over a one-year period. The results showed that the microplastic abundance ranged from 0 to over 1000 particles per liter. Fibers were the dominant form at all stations. Microplastics 249-100 µm were the dominant size, and transparency was the color most found at all stations. Polyethylene and ethylene-vinyl acetate were the major types of microplastics, accounting for 50% overall. The pollution load index revealed that over 70% of sampling stations were at hazard level I. However, the hazardous index was categorized as level III with a value of 662.3 due to the presence of the most hazardous polymer named polyurethane. Further investigations into the risk assessment of MP can reveal crucial knowledge for understanding the microplastic cycle.

Evaluation of Istanbul from the environmental components' perspective: what has changed during the pandemic?

This study aims to determine the 1-year change over the pandemic period in Istanbul, the megacity with the highest population in Turkey, based on environmental components. Among the environmental topics, water consumption habits, changes in air quality, changes due to noise elements, and most importantly, the changes in usage habits of disposable plastic materials that directly affect health have been revealed. The results obtained showed that, in Istanbul, 8.1 × 108 gloves should be considered waste, and considering the population living in districts along coastal areas, the number of waste masks that are likely to end up in the sea was 325.648 pieces/day. The results of the air quality and noise measurements during the pandemic showed that reductions in parallel with human activities were recorded with the lockdown effect. The average noise values of the districts along both sides of the Bosporus, where urbanization is concentrated, were between 50 and 59 dB. The precautions taken during the pandemic have had an effective role in reducing air pollution in Istanbul. In the measurements, the parameters with effective reductions were PM10 (7-47%), PM2.5 (13-48%), NO2 (13-38%), and SO2 (10-56%). As a result, Istanbul's year of changes during the pandemic period, in terms of water, air, noise, and solid plastic wastes, which are the most important components of the environment, is presented.

The spatial and temporal changes of beach litter on Istanbul (Turkey) beaches as measured by the clean-coast index.

Possible access routes of macro and mesoplastics, acting as the main sources of pollution in the coastal ecosystem, are examined as a case study on four beaches along the Istanbul coast. A total number of 3787 items belonging to 12 categories of debris types were collected as follows: macroplastics 47.8%; mesoplastics 9.2%; and others 43.0% such as paper pieces, glass pieces and metal beverage cans. Clean-coast and carbonyl indexes were also used to identify the level of cleanliness of the sampling sites. The clean-coast index revealed that all of the sample sites were categorized as extremely dirty. Moreover, carbonyl index results indicate that 35.7% of the samples were at a high oxidation level indicating that some of the particles relatively spend more time on beaches. The litter concentration and surface oxidation results were addressing issues that should be taken into consideration to improve litter management strategies of the beaches.

A comprehensive bibliometric overview: antibiotic resistance and Escherichia coli in natural water.

The environment is the most important reservoir for both resistance mechanisms and gene transfer in biological science studies. This study gives a bibliometric overview of studies of "antibiotic resistance" and "Escherichia coli" in the field of "Agricultural and Biological Sciences" from 2015 to 2019 to assess both research trends and scholarly networks in diverse research disciplines. The two keywords of "antibiotic resistance" and "Escherichia coli" were selected to search in the Scopus database. Each review article was categorized into materials, natural waters (i.e., seawater, freshwater) and wastewater, journal name, and quartile in category of the journal, the year of publication, and the country. Bibliometric indicators and visualization maps were utilized to analyse the retrieved data quantitatively and qualitatively. A total of 1376 publications in the field of agricultural and biological sciences over the last 5 years were obtained using the keywords of antibiotic resistance and Escherichia coli. With additional keywords of freshwater and wastewater, 4 and 24 studies were obtained, respectively. Wastewater was found to be the most common working environment for the keywords of antibiotic resistance and Escherichia coli. It is also found that the studies of antibiotic resistance are mainly conducted in wastewater environments, focusing on human and food health. Working under "One Health" consisting of human, animal and agriculture, and environmental health could be the only permanent and effective approach to solving antibiotic resistance-related issues.

Microplastic contamination in surface waters of the Küçükçekmece Lagoon, Marmara Sea (Turkey): Sources and areal distribution.

The distribution of freshwater and marine microplastics (MPs) varies due to the difference in fresh and seawater densities and MP sources. This study aims to investigate the abundance of MPs and their possible sources in surface waters of different ecosystems, such as sea, lagoon, and lake. We classified MPs in terms of their color and type and established the relationship between the MPs in surface waters with different characteristics. The mean MP abundance (33 particles L-1) detected herein was higher than that in the previously conducted studies. Fragment particles (37.95%) were determined to be the dominant MP type, and the predominant MP color was blue (75.28%). As for the seasonal MP distribution, its highest content (48.03 particles L-1) was observed in autumn, unlike that reported by other studies. The findings of this study reveal the effects of wastewater treatment plant (WWTP) discharge and current flow on the MP distribution in the study area. This study aims to provide representative data on the MP abundance and distribution, as well as MP-affecting parameters for similar aquatic areas in other parts of the world.