Microplastics have become a major environmental concern globally due to their potential impact on ecosystem function. They are known to be ubiquitously present, persistent and bio-accumulative, yet there is a lack of abundance quantifications in freshwater shorelines. Furthermore, there is little understanding of combined effects of seasonality and human population density on the extent of microplastic pollution. In this study, we assessed microplastics in sediment along a subtropical reservoir shoreline across three seasons and seven sites to understand microplastic pollution dynamics along a human population gradient. Multivariable analysis was used to assess relationships among substrate embeddedness, sediment organic matter, human population density and microplastic particle densities and characteristics. Microplastic densities were relatively high during the hot–dry season (mean range 120–6417 particles kg⁻¹ dwt) whilst the hot–wet season had the lowest densities (mean range 5–94 particles kg⁻¹ dwt). Microplastic abundances were positively correlated with population density, demonstrating the direct effects of human activity on microplastic contamination. These results highlight the need to further explore microplastic distribution patterns in freshwater ecosystems in the Southern Hemisphere. Furthermore, our findings suggest particular risk for fauna during low rainfall periods through microplastic concentration effects.

The aim of the study was to evaluate the influence of the application of increasing proportions (0%, 10%, 25%, 50%, 75%, and 100%) of an admixture of PCB-contaminated Hudson River sediment collected from the Upper Hudson River, near Waterford, Saratoga county (New York, USA) on soil properties, phytotoxicity, and biometric and physiological responses of cucumber (Cucumis sativus L. cv ‘Wisconsin SMR 58’) and zucchini (Cucurbita pepo L. cv ‘Black Beauty’) grown as potential phyto- and rhizoremediators. The experiment was performed for 4 weeks in a growth chamber under controlled conditions. Amendment of Hudson River sediment to soil led to a gradual increase in PCB content of the substratum from 13.7 μg/kg (with 10% sediment) to 255 μg/kg (with 100% sediment). Sediment amendment showed no phytotoxic effects during the initial stages, even Lepidium sativum root growth was stimulated; however, this positive response diminished following a 4-week growth period, with the greatest inhibition observed in unplanted soil and zucchini-planted soil. The stimulatory effect remained high for cucumber treatments. The sediment admixture also increased cucurbit fresh biomass as compared to control samples, especially at lower doses of sediment admixture, even though PCB content of the soil amended with sediment increased. Cucurbits’ leaf surface area, in turn, demonstrated an increase for zucchini, however only for 50% and 75% sediment admixture, while cucumber showed no changes when lower doses were applied and decrease for 75% and 100% sediment admixture. Chlorophyll a + b decreased significantly in sediment-amended soils, with greater inhibition observed for cucumber than zucchini. Our results suggest that admixture of riverine sediment from relatively less-contaminated locations may be used as soil amendments under controlled conditions; however, further detailed investigation on the fate of pollutants is required, especially in terms of the bioaccumulation and biomagnification properties of PCBs, before contaminated sediment can be applied in an open environment.

Seawater pH lowering, known as ocean acidification, is considered among the major threats to marine environment. In this study, post-spawning adults of the sea urchin Paracentrotus lividus were maintained at three pH values (8.0, 7.7, 7.4) for 60 days. Physiological, biochemical, cellular, behavioural and reproductive responses were evaluated in males and females. Significant differences between sexes were observed, with higher ammonia excretion and lower catalase activity in males. Respiration rate (after 21 days), catalase activity in gonads and total coelomocyte count showed the same increasing trend in males and females under low pH. Ammonia excretion, gonadosomatic index and lysozyme activity exhibited opposite responses to low pH, with an increasing trend in males and decreasing in females. Results demonstrated that exposure to low pH could result in different response strategies of male and female sea urchins at a physiological, biochemical and immunological level. Reduced female gonadosomatic index under low pH suggested decreased energy investment in reproduction.

We present a synthetic review and expert consultation that assesses the actual risks posed by arthropod pests in four major crops, identifies targets for integrated pest management (IPM) in terms of cultivated land needing pest control and gauges the implementation “readiness” of non-chemical alternatives. Our assessment focuses on the world’s primary target pests for neonicotinoid-based management: western corn rootworm (WCR, Diabrotica virgifera virgifera) in maize; wireworms (Agriotes spp.) in maize and winter wheat; bird cherry-oat aphid (Rhopalosiphum padi) in winter wheat; brown planthopper (BPH, Nilaparvata lugens) in rice; cotton aphid (Aphis gossypii) and silver-leaf whitefly (SLW, Bemisia tabaci) in cotton. First, we queried scientific literature databases and consulted experts from different countries in Europe, North America, and Asia about available IPM tools for each crop-pest system. Next, using an online survey, we quantitatively assessed the economic relevance of target pests by compiling country-level records of crop damage, yield impacts, extent of insecticide usage, and “readiness” status of various pest management alternatives (i.e., research, plot-scale validation, grower-uptake). Biological control received considerable scientific attention, while agronomic strategies (e.g., crop rotation), insurance schemes, decision support systems (DSS), and innovative pesticide application modes were listed as key alternatives. Our study identifies opportunities to advance applied research, IPM technology validation, and grower education to halt or drastically reduce our over-reliance on systemic insecticides globally.

Assisted phytoremediation using amendments is a cost-effective and environmentally friendly approach to control soil pollution. However, amendment type, combination and application rate can influence process effectiveness. In the present study, the effect of the association of red mud and carbon-based amendments on the physicochemical properties of a former mine soil as well as the growth and metal(loid) uptake of Trifolium repens was investigated. For this purpose, a mesocosm experiment was set up using a former mine technosol highly contaminated by As and Pb, amended with red mud combined with different carbon-based amendments, i.e., bamboo biochar, oak biochar, steam activated carbon and acidic activated carbon, and sown with Trifolium repens. The final goal was to determine which amendment combination allows soil metal(loid) immobilization and an efficient plant growth. Results showed that all the four different treatments improved soil characteristics by increasing pH and electrical conductivity and reducing redox potential. All the treatments were also effective in reducing soil pore water lead concentrations. Among the four treatments, the addition of red mud and acidic activated carbon in the soil showed better results regarding Trifolium repens growth. Finally, when grown on the soil amended with red mud and acidic activated carbon, Trifolium repens presented mainly a metal(loid) storage in roots, making it a right candidate for the establishment of a vegetation cover.

China’s fiscal decentralization has the dual characteristics of revenue decentralization and expenditure decentralization, and their impacts on green total factor productivity are also different. By calculating the Malmquist-Luenburger index and using the Spatial Durbin Model, this study examines the effects of dual decentralization on green total factor productivity (GTFP) from the perspective of fiscal competition. It was found that revenue decentralization significantly hindered the improvement of a local area’s GTFP, and that the impact of fiscal revenue competition on a local area’s GTFP is also significantly negative. The expenditure decentralization and the fiscal expenditure competition among different areas are conducive to improving the local area’s GTFP. Moreover, the impact of revenue decentralization on efficiency improvement is significantly negative, while the expenditure decentralization is conducive to technical progress. All these findings may provide enlightenment for optimizing China’s fiscal decentralization and promoting high-quality economic development.

The classification of wastes regarding hazardous property HP 14 (ecotoxicity) is essential for proper waste management. In the EU, HP 14 has been estimated based on waste chemical composition rather than using biotests, and guidelines for experimental assessment are still lacking. This study aims at evaluating the potential ecotoxicological impacts of weathered coal fly ash (CFA) from a landfill, as a case study to assess the current EU methodology used to classify wastes regarding HP 14. A large amount of CFA is still landfilled, but its valorisation would be of interest. The analysis was based on the chemical composition of CFA (in ClassifyMyWaste software), and on a battery of five biotests applied to eluates, with Lepidium sativum, Aliivibrio fischeri, Raphidocelis subcapitata, Lemna minor and Daphnia magna. Through chemical analysis, most of the simulations with data from the literature indicated “Possible Hazard”, including the sample of this work. Biotests revealed low impairment for most endpoints. D. magna was the most sensitive organism, but the inhibitory effect was significantly reduced after pH adjustment of the eluate. The test with A. fischeri does not seem to be adequate to assess CFA due to the high variability observed in results. The methodology involving a simple battery of bioassays was proven to be enlightening, providing relevant results for HP 14 assessment. The chosen battery of biotests (excluding the A. fischeri test) may be a good starting point to represent the aquatic environment in this context. In short, it seems that weathered CFA can be considered non-hazardous, and therefore the material under analysis could be valorised in practical applications without significant ecotoxic effect on the environment.

Freshwater crayfish are bioindicators of environmental pollution, often used for the assessment of heavy metal (HM) presence in the tissues, a time-consuming and expensive task. In this study, we propose the use of the vibrational spectroscopy to detect in a fast, non-destructive and sensitive way the presence of HM in the cephalothorax exoskeleton of the freshwater crayfish. Incorporation of HM into the cephalothorax exoskeleton was investigated under controlled laboratory conditions. In particular, the cephalothorax exoskeleton of five crayfish species (Astacus leptodactylus, Procambarus clarkii, Austropotamobius pallipes, Faxonius limosus, and Pacifastacus leniusculus) was analyzed by attenuated total reflection–Fourier transformed infrared (ATR–FTIR) spectroscopy in the presence or absence of cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni), and zinc (Zn) up to 4 weeks at various concentrations (0.01, 0.1, 1, 10, ppm). The ATR–FTIR profile of the crayfish cephalothorax exoskeleton was compatible with the presence of amorphous calcium carbonate, chitin, and proteins. The incubation with the HM revealed two main modifications: the shift of the peak from 859 to 872 cm⁻¹ and the appearance of a peak at 712 cm⁻¹. Both are ascribable to the HM interaction with calcium carbonate. The absorbance of both peaks increased along with the time of incubation, and the HM concentration. We conclude that ATR–FTIR analysis can be a useful, quick, and cost-sensitive tool to detect HM presence in the crayfish cephalothorax exoskeleton. However, it has to be regarded as a non-specific analytical technique for assessing HM contamination, since it is unable to discriminate between different HM.