Historical (or legacy) contaminants, such as metals and persistent organic pollutants (POPs; e.g., polychlorinated biphenyls) have been measured in circumpolar subpopulations of polar bears, especially from Hudson Bay, East Greenland, and Svalbard, but substantially less is currently known about new and/or emerging contaminants such as polychlorinated naphthalenes, current-use pesticides, organotins, and polycyclic aromatic compounds (PACs). The polar bear (Ursus maritimus) is an apex Arctic predator that accumulates high levels of bioaccumulative POPs and mercury (Hg), but there is currently no comprehensive profiling of the present knowledge on contaminants in tissue and body compartments in polar bears. Based on current literature reports and data, and including archived museum samples (as far back as the 1300s) and up to 2018, the aim of this review is to utilize available data to examine the comparative distribution and burden of mainly lipophilic contaminants in kidney, liver, fat, and other body compartments, such as milk, blood, and brain. Highlight outcomes from this review include the following: (1) the kidneys are one of the most important tissue depots of contaminants in polar bears; (2) there is a critical lack of data concerning the presence of metals of concern (other than Hg); and (3) there currently are no data available on the concentrations of many newer and emerging contaminants, such as PACs, which is especially relevant given the increasing oil and gas development in regions, such as the Beaufort Sea (Canada). Additionally, given the vulnerability of polar bear populations worldwide, there is a need to develop non-invasive approaches to monitor contaminant exposure in polar bears.

Microplastics (MPs) are one of the major threats to aquatic ecosystems. Surprisingly, our knowledge of its occurrence and its impact on the organisms that dwell in small water bodies is still scarce. The aim of this study was to investigate the occurrence and chemical composition of MPs in tadpoles of pond-breeding amphibians. In total, 201 tadpoles belonging to 5 species were collected from 8 ponds located in southwestern Poland. MPs were found in all examined sites and in all studied species. Among those tested, 53 (26%) tadpoles ingested a total of 71 MPs. IR-ATR analysis revealed that particles were of anthropogenic origin and included nylon, polyurethane, polyisoprene and 1,2 polybutadiene.

Waste biomass can be recycled to prepare biochar for soil restoration, in which process soil fertility would not be lost. In this work, biochar was prepared from waste pomelo peel, combined with ZnO, to be used to immobilize Cu(II) in contaminated soil, whose maximum adsorption capacity was up to 216.37 mg g⁻¹. Due to combination of ZnO, the BET surface area of biochar increased from 2.39 to 18.53 m² g⁻¹. Meanwhile, the surface functional groups increased, which was conducive to fixation of metal ion on the surface of biochar. Both pseudo-second-order kinetics and Langmuir isotherm model fit the experimental data well. Adsorption was easy to happen since the adsorption site on the surface of biochar/ZnO had a strong affinity with Cu(II). In addition, mechanism investigation indicated that Cu(II) was bond with biochar/ZnO mainly by non-bioavailable state (75.6%) primarily. It inferred that biochar/ZnO was an efficient and promising passivator in reducing heavy metal risk in soil.

Concurrent indoor–outdoor fine particulate matter (PM₂.₅) measurements were conducted at urban, suburban, and rural sites in Harbin, a megacity in the northeast of China. Chemical constituents of indoor–outdoor PM₂.₅ were determined. Infiltration factors (FINF) of all sites were calculated according to the indoor to outdoor (I/O) ratios of PM₂.₅ based on the regression analysis. Linear discriminant analysis (LDA) is applied to determine the indoor–outdoor relationship. Secondary organic carbon (SOC) was calculated on the basis of organic carbon to elemental carbon (OC/EC) ratios. The mean concentrations of indoor and outdoor PM₂.₅ were 166.4 ± 32.5 μg/m³ and 228.4 ± 83.7 μg/m³, respectively, during the heating period. OC/EC and potassium ion to elemental carbon (K⁺/EC) ratios verified that biomass was an important source in Harbin especially for rural sites. The nitrate to sulfate (NO₃⁻/SO₄²⁻) ratio indicates the higher contribution of traffic emissions in urban sites. Cr was the only species that exceeded the guidelines of WHO 2002, which was mainly emitted from coal and oil combustion. SOC/OC and NO₃⁻/SO₄²⁻ ratios, and ion-balanced acidity (the ratio of cation to anion, R₊/₋) showed a large urban–rural and indoor–outdoor difference. The highest SOC/OC ratio was found at urban sites, up to 38.3% for indoors. SOC/OC ratios and R₊/₋ values of indoor environments were higher, which is attributed to the conducive condition of forming the secondary pollutants during the heating period. The results of LDA indicated that the distributions of the chemical components of PM₂.₅ at three sites were statistically dissimilar. Graphical abstract

Iron mining residue was evaluated as a potential catalyst for heterogeneous Fenton/photo-Fenton degradation of sulfonamide antibiotics. The residue contained 25% Fe₂O₃ and 8% CeO₂, as determined by X-ray fluorescence spectroscopy, as well as other minor phases such as P₂O₅, SiO₂, and TiO₂. X-ray photoelectron spectroscopy analysis revealed a lower content of iron oxides on the surface, which restricted interaction of the residue with H₂O₂. Despite this limitation and the relatively low specific surface area (26 m² g⁻¹) of the crude iron mining residue (without any pretreatment), the material presented high catalytic activity for Fenton degradation of sulfonamide antibiotics. The degradation was strongly dependent on the initial pH, showing the highest efficiency at pH 2.5. For this condition, a concentration of sulfathiazole below the detection limit was obtained within 30 min, under black light irradiation and using 0.3 g L⁻¹ residue, with low H₂O₂ consumption (0.2 mmol L⁻¹). The residue also provided highly efficient sulfathiazole degradation in the dark, with the concentration of the antibiotic decreasing to an undetectable level after 45 min. Simultaneous degradation of two sulfonamide antibiotics revealed higher recalcitrance of sulfamethazine, compared to sulfathiazole, but the levels of both antibiotics decreased to below the detection limit after 45 min. The residue was very stable, since no significant concentration of soluble iron was detected after the degradation process. Furthermore, high catalytic activity was maintained during up to five cycles, showing the potential of this material for use as a low-cost and environmentally compliant catalyst in Fenton processes.

Phosphorus reuse by application of biochar is a recent concept that needs to be supported by long-term field data. To monitor biochar’s long-term effects on P turnover, one-off biochar was applied in 2013 with mineral NPK fertilizers being applied every year since then. Biochar application rates included 0 t ha⁻¹ (CK), 15.75 t ha⁻¹ (BC1), 31.5 t ha⁻¹ (BC2), and 47.25 t ha⁻¹ (BC3). Over the 5 years’ field experiment, P distribution in soil profile, inorganic and organic P fractions in bulk, and rhizosphere soil and maize P uptake were determined. The results showed that biochar reduced the inorganic P fractions (Ca₂-P, Ca₈-P, Al-P, Fe-P and O-P by 4.8–33.7%, 8.8–59.0%, 13.7–28.6%, 8.4–17.6%, and 3.3–25.5%, respectively), and increased organic P fractions (MLOP and HROP by 67.2–11.6% and 18.8–87.7%, respectively) in bulk soil, while in rhizosphere soil, Fe-P and MLOP were decreased by 13.4–34.5% and 67.2–111.6%, respectively, in 2017. After the application of biochar for 5 years, moderately labile organic phosphorus (MLOP), moderately resistant organic phosphorus (MROP), and highly resistant organic phosphorus (HROP) with different biochar treatments were enhanced by 12.8–42.7%, 20.1–48.0%, and 5.5–66.6%, respectively, but Ca₈-P, Al-P, O-P, and Ca₁₀-P were all decreased by 18.6–24.9%, 16.4–21.4%, and 3.3–23.48%, respectively. Total P storage in 0–100 cm was declined by biochar. Increases in maize P uptake in the stover (38.6–71.3%) and grain (20.9–25.5%) were occurred after 31.5 t ha⁻¹ and 47.25 t ha⁻¹ biochar addition. To sum up, biochar is found to regulate the distribution, storage, and transformation of soil P, which lead to increase in maize P uptake.

Human’s activities dominates many aspects of the Earth’s environment; thus animals are forced to adapt and respond to the resulting changes in habitat structure and functioning due to anthropogenic pressure. Along with the growing human population and the associated amount of waste produced, the amount of different type of physical contamination component in environment is increasing. Incorporation of debris in nests may be a mounting avian response to anthropogenic pollution. In this research, we quantified the constituent pieces and total mass of human-derived materials incorporated in white stork nests. The study was conducted on four locations in central Spain where white storks nest along a urbanization gradient. In total, we examined 49 nests. This study demonstrates that the incorporation of debris by white storks into their nests is related to human activity, measured by the Human Footprint Index (HFI). Moreover, the distance between these nests and landfills predicts the occurrence of debris incorporated into nests. Our study shows that birds nest building behaviour is impacted by human activities and pollution in environment.

The total cultivated area in Brazil reached to 62 million ha in 2018, with the predominance of genetically modified soybean and corn (36 and 17 million ha, respectively) in no-tillage systems. In 2018, 5.3 × 10⁵ Mg of active ingredient of pesticides was applied in cropfields, representing about 7.3 L of commercial product by habitant. However, the monitoring of water courses contamination by pesticides remains scarce and is based on traditional grab sampling systems. In this study, we used the grab (water) and passive sampling (Polar Organic Chemical Integrative Sampler—POCIS) to monitor pesticide contamination in the river network of a representative agricultural catchment of southern Brazil. We selected 18 sampling sites located in tributaries and in the main course of the Guaporé River, in Rio Grande do Sul State, with different land use predominance including forest, urban, and agricultural areas. Altogether, 79 and 23 pesticides were, respectively, analyzed in water and POCIS samples. The water of Guaporé River and its tributaries were highly contaminated by many pesticides, especially by four herbicides (2,4-D, atrazine, deethyl-atrazine, and simazine), three fungicides (carbendazim, tebuconazole, and epoxiconazole), and one insecticide (imidacloprid). The amount, type, and concentration of pesticides detected were completely different depending on the sampling technic used. POCIS was effective to discriminate the contamination according to the main land use of each sampling site. The monitored areas with the predominance of soybean cultivation under no-tillage tended to have higher concentrations of fungicide, while in the more diversified region, the herbicides showed higher values. The presence of five herbicides used in corn and grassland forage production was correlated with areas of integrated crop-livestock systems, in contrast to higher contamination by 2,4-D in areas of intensive production of soybean and winter cereals.

In this study, polypropylene (PP) plastic wastes were pyrolysed. Solid pyrolysis product (char) was used as filler material for the preparation of epoxy composite. 300, 400, 500, 600 and 700 °C were selected as final pyrolysis temperatures. Solid pyrolysis product (char) was analysed by elemental, FTIR, SEM, BET and TGA analysis. The epoxy composite samples were prepared with char obtained from pyrolysis. Mechanical properties of composites were analysed by hardness, tensile strength, elongation at break, electrical conductivity tests to explain the effects of pyrolysis temperature and char doses over composite properties. Thermogravimetric properties of composites were determined by TGA analyses. The water absorption behaviour of composite samples was determined by water adsorption test. Epoxy composite produced from PP char obtained under 300 °C showed the most ideal behaviour.

Metals are widely released and distributed in soil and may have a negative impact on terrestrial organisms. Over the past years, a series of criteria or standards for assessing the ecological risks and toxicity of metals have been published in many countries; however, few studies have investigated their metal ionic properties and toxicity. In the present study, the ecological risk assessment screening values (ERASV) recommended by the Oregon Department of Environmental Quality were selected to investigate the correlation between metal toxicity and their ionic characters based on the hard and soft acids and bases (HSAB) concept. The results showed that more ionic characters were significantly correlated with ERASV using the HSAB theory, while only one metal ionic characteristic was correlated with ERASV in organisms. For borderline metal ions, maximum complex stability constants (log βn) and the softness (δp) of borderline ions were correlated with ERASV, while log βn and electronegativity (Xm) were significantly related to ERASV for borderline plus hard ions, and the boiling point (BP) and electron density (AR/AW) (AR indicates atomic radius and AW is atomic mass) were significantly related to ERASV for borderline plus soft ions. These results indicated that different metal ion characteristics play different roles in different types of metal toxicity in organisms and the mechanisms of toxicity are different. Based on these relationships, a set of quantitative ion characteristic parameter-activity relationship (QICAR) was developed. The QICAR predicted ERASV for metals that were reasonably consistent with those recommended by the Oregon Department of Environmental Quality, with differences between them generally < 2.0 orders of magnitude. However, there were discrepancies between the recommended and predicted values, and these discrepancies may be related to terrestrial geochemical properties. These soil properties should be further considered when developing QICAR models in future studies, such as soil type, organic matter, and pH. Overall, the QICAR models were able to determine the relationships between metal ionic properties and their toxicity and will be useful for assessing toxicity data on unknown toxic metals and will provide a basis for ecological assessment.