Urbanization can considerably affect water reservoirs by, inter alia, input, and accumulation of contaminants including metals. Located in the course of River Cybina, Maltański Reservoir (Western Poland) is an artificial shallow water body built for recreation and sport purposes which undergoes restoration treatment (drainage) every 4 years. In the present study, we demonstrate an accumulation of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in water, sediment, three bivalve species (Anodonta anatina, Anodonta cygnea, Unio tumidus), and macrophyte Phragmites australis collected before complete drainage in November 2012. The mean concentrations of metals in the sediment, bivalves, and P. australis (roots and leaves) decreased in the following order: Fe > Mn > Zn > Cu > Cr > Ni > Pb > Co > Cd. A considerably higher bioconcentration of metals was observed in samples collected from the western and southern sites which undergo a higher degree of human impact. Sediments were found to be a better indicator of metal contamination than water samples. Interspecific differences in levels of metal accumulation were found between investigated unionids. U. tumidus accumulated higher levels of Cr, positively correlated with ambient concentrations, predisposing this species as a potential bioindicator of this metal in aquatic environments. On the other hand, species of Anodonta genus demonstrated higher accumulation of Cu and Cd. Positive correlations were found between Pb content in the sediments and tissues of all three bivalve species. In P. australis, metals were largely retained in roots except for Cd and Pb for which higher concentrations were found in leaves suggesting additional absorption of these metals from aerial sources. P. australis and bivalve from the Maltański Reservoir may be a potential source of toxic metals for animals feeding upon them and contribute to further contamination in the food chain.

Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite. Moreover, a major driver of cryoconite colouring was the concentration of organic matter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceae were the most common. The most of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb and Hg in cryoconite collected from European glaciers near industrialized regions, corroborating cryoconite as element-specific collector and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may be more than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystems.

Arthrospira spp. (known commercially as Spirulina) and Chlorella spp., valued for their evidence-based nutritional and bioactive properties, are cultivated for the purpose of production of food supplements for worldwide distribution. However, the quality and safety of the final product depends on culturing and manufacturing conditions. The present study investigated the content of toxic elements (As species, Al, Cd, Hg, Ni, Pt, Pb, Cr (VI), rare earth elements) and minerals (Ca, Co, Cr, Cu, Fe, K, Na, Mg, Mn, P, Zn) in Chlorella (n = 10) and Spirulina (n = 13) food supplements registered in the European Union. Considering the most common recommended daily dosage 3.0, supplementation with any of the studied product would contribute significantly to mineral intake, with the exception of Fe which was found at high but acceptable levels in both Spirulina and Chlorella formulas. The majority of products revealed agreement between factual mineral content and that declared on the label, the only exception being Cu content in Chlorella products found to be significantly higher (> 130%). All studied supplements were found to have Cd, Hg, and Ni levels much below safety limits, although selected ones were characterized by increased content of Al, Pb, and inorganic As. No hexavalent Cr was detected in the studied products. The study highlights that microalgal supplements can be safe for consumers if appropriate measures are taken to ensure consumer safety, although it underlines the continuous need to monitor these products in order to fully eliminate those of low quality.

The global use of pharmaceuticals is on the systematic rise and leads to contamination of surface waters with xenobiotic compounds with a wide range of bioactivity. Waters that receive urban and medical effluents are particularly threatened. The presence of pharmaceuticals in these ecosystems can lead to unpredictable ecological impacts and responses, and may also have an impact on human health. At the same time the identification and quantification of these chemicals, to a large extent remains a subject to scientific investigation than part of a thorough monitoring programme. Their biological effects on aquatic organisms are mainly recognized experimentally and often using concentrations far exceeding environmentally relevant levels. This review paper defines the main sources of pharmaceuticals in the aquatic environment, discusses the fate of these compounds and summarizes the current state-of-the-art of pharmaceutical monitoring in Polish surface waters.

Following decades of global extermination, the general population of the great cormorant (Phalacrocorax carbo L.) is on the rise. The lack of regular predators, highly skilled fish rapacity, rapid metabolism, significant rate of excretion and ability to form large nesting colonies on relatively small areas lead to numerous environmental consequences of cormorant presence. Here we comprehensively review the occurrence and distribution of this species and, in particular, its multi-faceted impact on terrestrial and aquatic ecosystems and the main routes through which these impacts are being manifested. The bird-induced chemical loading and its biological and ecological consequences, and the effects on microbial pollution and pathogen dispersion are discussed in particular. The need for further investigation to fully elucidate particular effects is stressed throughout the paper. It is concluded that the environmental effects of great cormorants are rather complex, can lead to serious ecosystem modifications and that the presence of these birds should be taken into consideration in ecological assessment and monitoring.