Environments

15 pages, 1514 KiB

Open AccessArticle

Mercury Concentration and Distribution in Remiges, Rectrices, and Contour Feathers of the Barn Swallow Hirundo rustica

by Luca Canova, Federica Maraschi, Roberto Ambrosini, Alessandra Costanzo, Marco Parolini, Antonella Profumo, Andrea Romano, Diego Rubolini and Michela Sturini

Environments 2025, 12(7), 249; https://doi.org/10.3390/environments12070249 - 18 Jul 2025

Abstract

Feathers are commonly used to monitor trace elements in birds, including heavy metals. Typically, a single feather is analyzed to avoid harming living birds, assuming it reflects the organism’s overall contamination. To verify this assumption, we analyzed mercury concentrations in 12 flight and [...] Read more.

Feathers are commonly used to monitor trace elements in birds, including heavy metals. Typically, a single feather is analyzed to avoid harming living birds, assuming it reflects the organism’s overall contamination. To verify this assumption, we analyzed mercury concentrations in 12 flight and contour feathers from 25 barn swallows Hirundo rustica (16 adults and nine juveniles) that had died accidentally in a colony of the Po Plain (northern Italy). The median concentration in all feathers examined was 1.03 µg g⁻¹ in adults (range 0.76 µg g⁻¹–1.30 µg g⁻¹) and 0.39 µg g⁻¹ in juveniles (range 0.28 µg g⁻¹–0.71 µg g⁻¹), which is consistent with the results of similar research carried out on other world regions. No significant differences were observed between sexes, whereas marked differences were observed between adults and juveniles. In adults, mercury concentration was similar across remiges, rectrices, and contour feathers while in juveniles it was higher in contour feathers than in flight feathers. Mercury accumulation was highest in primary remiges and contour feathers, accounting for 67.6% of total mercury in adults and 77.5% in juveniles. However, primary remiges cannot be collected from live adults due to their importance in flight. In juveniles, contour feathers carry about 50% of total mercury, suggesting ventral and dorsal plumage may be useful for assessing mercury burden. Our findings are consistent with the hypothesis that mercury accumulation in feathers aids detoxification, with early-molted feathers (primary remiges and contour feathers) containing higher mercury levels than those replaced later (rectrices and secondary remiges). Full article

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17 pages, 4514 KiB

Open AccessArticle

Using Tourist Diver Photos to Assess the Effects of Marine Heatwaves on Central Red Sea Coral Reefs

by Anderson B. Mayfield

Environments 2025, 12(7), 248; https://doi.org/10.3390/environments12070248 - 18 Jul 2025

Abstract

As marine heatwaves increase in frequency, more rapid means of documenting their impacts are needed. Herein, several thousand coral reef photos were captured before, during, and/or after high-temperature-induced bleaching events in the Central Red Sea, with a pre-existing artificial intelligence (AI), CoralNet, trained [...] Read more.

As marine heatwaves increase in frequency, more rapid means of documenting their impacts are needed. Herein, several thousand coral reef photos were captured before, during, and/or after high-temperature-induced bleaching events in the Central Red Sea, with a pre-existing artificial intelligence (AI), CoralNet, trained to recognize corals and other reef-dwelling organisms. The AI-annotated images were then used to estimate coral cover and bleaching prevalence at 22 and 11 sites in the Saudi Arabian and Egyptian Red Sea, respectively. Mean healthy coral cover values of 12 and 9%, respectively, were documented, with some sites experiencing >60% bleaching during a summer 2024 heatwave that was associated with 21–22 and 25 degree-heating weeks at the Saudi Arabian and Egyptian reefs, respectively. As a result of this mass bleaching event, coral cover at the survey sites has declined over the past 5–10 years by upwards of 6-fold in the most severely impacted regions. Although some recovery is likely, these Central Red Sea sites do not appear to constitute “climate refugia,” as may be the case for some reefs farther north. Full article

(This article belongs to the Special Issue Coastal and Marine Environmental Ecology Problems Identified and Addressed by Means of Artificial Intelligence Tools)

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18 pages, 2311 KiB

Open AccessArticle

A Rapid Method for Identifying Plant Oxidative Stress and Implications for Riparian Vegetation Management

by Mizanur Rahman, Takashi Asaeda, Kiyotaka Fukahori, Md Harun Rashid, Hideo Kawashima, Junichi Akimoto and Refah Tabassoom Anta

Environments 2025, 12(7), 247; https://doi.org/10.3390/environments12070247 - 17 Jul 2025

Viewed by 101

Abstract

Native and invasive plants of the riverain region undergo a range of environmental stresses that result in excess reactive oxygen species (ROS). Hydrogen peroxide (H₂O₂) is a relatively stable and quickly quantifiable way among different ROS. The herbaceous species [...] Read more.

Native and invasive plants of the riverain region undergo a range of environmental stresses that result in excess reactive oxygen species (ROS). Hydrogen peroxide (H₂O₂) is a relatively stable and quickly quantifiable way among different ROS. The herbaceous species including Artemisia princeps, Sicyos angulatus, and Solidago altissima were selected. The H₂O₂ and photosynthetic pigment of leaves were measured, soil samples were analyzed to quantify macronutrients such as total nitrogen (TN), total phosphorus (TP), and soil moisture, and photosynthetic photon flux density (PPFD) was also recorded at different observed sites of Arakawa Tarouemon, Japan. The H₂O₂ concentration of S. altissima significantly increased with high soil moisture content, whereas A. Princeps and S. angulatus significantly decreased with high soil moisture. In each species, H₂O₂ was negatively correlated with chlorophyll a (chl a) and chlorophyll b (chl a). When comparing different parameters involving TN, TP, PPFD, and soil moisture content with H₂O₂ utilizing the general additive model (GAM), only soil moisture content is significantly correlated with H₂O₂. Hence, this study suggests that H₂O₂ would be an effective biomarker for quantifying environmental stress within a short time, which can be applied for riparian native and invasive plant species vegetation regulation. Full article

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20 pages, 2246 KiB

Open AccessArticle

The Occurrence and Distribution of Herbicides in Soil and Irrigation Canals in a High-Input Farming Region of Serbia

by Dragana Linda Mitić, Mira Pucarević, Mira Milinković, Sanja Lazić, Aleksandra Šušnjar, Slavica Vuković, Jelena Ećimović, Siniša Mitrić and Dragana Šunjka

Environments 2025, 12(7), 246; https://doi.org/10.3390/environments12070246 - 17 Jul 2025

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Abstract

This study aims to improve the understanding of, and provide insights into, the environmental fate of herbicides currently used in agriculture, which is addressed through the analysis of the quality of canal water used for irrigation and the agricultural soil in the immediate [...] Read more.

This study aims to improve the understanding of, and provide insights into, the environmental fate of herbicides currently used in agriculture, which is addressed through the analysis of the quality of canal water used for irrigation and the agricultural soil in the immediate vicinity. The research was conducted in the main agricultural region of Serbia, characterized by intensive crop production in conventional agriculture. Monitoring was focused on the Danube–Tisza–Danube canal system, specifically the Bogojevo–Bečej section. The presence of 41 currently used herbicides was analyzed in 520 soil samples collected from two depths (0–30 cm and 30–60 cm), as well as in 100 canal water samples. Results showed a high frequency of clopyralid, 2,4-D-methyl ester, terbuthylazine, fenoxaprop-ethyl, and aclonifen, with the highest amountsbeingterbuthylazine and quizalofop-ethyl, which was possibly a consequence of their recent application shortly before sampling. Concentrations of herbicide residues at different depths were closely similar, without the impact of soil mechanical and chemical characteristics on herbicide levels. In canal water characterized as moderately salty and slightly alkaline, herbicide residues were far below the maximum allowable concentrations, suggesting that the canal water is suitable for aquatic life, irrigation, and other uses. The findings suggest that the appropriate use of herbicides in regions under intensive agriculture is important for reducing environmental contamination. Full article

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21 pages, 1897 KiB

Open AccessArticle

Simulation of Conventional WWTPs Acting as Mediators in H₂/CO₂ Conversion into Methane

by Rubén González and Xiomar Gómez

Environments 2025, 12(7), 245; https://doi.org/10.3390/environments12070245 - 16 Jul 2025

Viewed by 134

Abstract

CO₂-biomethanation was studied in the present manuscript by considering the direct injection of hydrogen into a conventional anaerobic digester treating sewage sludge within a simulated wastewater treatment plant (WWTP). The plant was simulated using the Python 3.12.4 software, and a Monte [...] Read more.

CO₂-biomethanation was studied in the present manuscript by considering the direct injection of hydrogen into a conventional anaerobic digester treating sewage sludge within a simulated wastewater treatment plant (WWTP). The plant was simulated using the Python 3.12.4 software, and a Monte Carlo simulation was conducted to account for the high variability in the organic content of the wastewater and the methane potential of the sludge. Two modes of operation were studied. The first mode involves the use of an anaerobic digester to upgrade biogas, and the second mode considers using the digester as a CO₂ utilization unit, transforming captured CO₂. Upgrading biogas and utilizing the extra methane to generate electricity within the same plant leads to a negative economic balance (first scenario). A hydrogen injection of 1 L of H₂/L_r d (volumetric H₂ injection per liter of reactor per day) was required to transform the CO₂ present in the biogas into methane. The benefits associated with this approach resulted in lower savings regarding heat recovery from the electrolyzer, increased electricity production, and an additional oxygen supply for the waste-activated sludge treatment system. Increasing the injection rate to values of 5 and 30 L of H₂/L_r d was also studied by considering the operation of the digester under thermophilic conditions. The latter assumptions benefited from the better economy of scale associated with larger installations. They allowed for enough savings to be obtained in terms of the fuel demand for sludge drying, in addition to the previous categories analyzed in the biogas upgrading case. However, the current electricity price makes the proposal unfeasible unless a lower price is set for hydrogen generation. A standard electricity price of 7.6 c€/kWh was assumed for the analysis, but the specific operation of producing hydrogen required a price below 3.0 c€/kWh to achieve profitability. Full article

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19 pages, 3993 KiB

Open AccessArticle

Optical Monitoring of Particulate Matter: Calibration Approach, Seasonal and Diurnal Dependency, and Impact of Meteorological Vectors

by Salma Zaim, Bouchra Laarabi, Hajar Chamali, Abdelouahed Dahrouch, Asmae Arbaoui, Khalid Rahmani, Abdelfettah Barhdadi and Mouhaydine Tlemçani

Environments 2025, 12(7), 244; https://doi.org/10.3390/environments12070244 - 16 Jul 2025

Viewed by 115

Abstract

The worldwide air pollution situation reveals significant environmental challenges. In addition to being a major contributor to the deterioration of air quality, particulate matter (PM) is also an important factor affecting the performance of solar energy systems given its ability to decrease light [...] Read more.

The worldwide air pollution situation reveals significant environmental challenges. In addition to being a major contributor to the deterioration of air quality, particulate matter (PM) is also an important factor affecting the performance of solar energy systems given its ability to decrease light transmission to solar panels. As part of our research, the present investigation involves monitoring concentrations of PM using a high-performance optical instrument, the in situ calibration protocol of which is described in detail. For the city of Rabat, observations revealed significant variations in concentrations between day and night, with peaks observed around 8 p.m. correlating with high relative humidity and low wind speeds, and the highest levels recorded in February with a monthly average value reaching 75 µm/m³. In addition, an experimental protocol was set up for an analysis of the elemental composition of particles in the same city using SEM/EDS, providing a better understanding of their morphology. To assess the impact of meteorological variables on PM concentrations in two distinct climatic environments, a database from the city of Marrakech for the year 2024 was utilized. Overall, the distribution of PM values during this period did not fluctuate significantly, with a monthly average value not exceeding 45 µm/m³. The random forest method identified the most influential variables on these concentrations, highlighting the strong influence of the type of environment. The findings provide crucial information for the modeling of solar installations’ soiling and for improving understanding of local air quality. Full article

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20 pages, 1892 KiB

Open AccessArticle

Effect of Slurry Acidification In-House by a Dynamic Spraying System on Ammonia and Greenhouse Gas Emissions from Pig-Fattening Farms in Hot Summer Climates

by Gema Montalvo, María Rodríguez, Carlos Piñeiro, Paloma Garcia-Rebollar and María J. Sanz

Environments 2025, 12(7), 243; https://doi.org/10.3390/environments12070243 - 16 Jul 2025

Viewed by 121

Abstract

Animal production generates gas emissions. It is imperative to reduce them as projections suggest that emissions will continue to increase with rising temperatures, alongside the intensification of agriculture to meet global food demand. Slurry acidification in-house can reduce these emissions. In this study, [...] Read more.

Animal production generates gas emissions. It is imperative to reduce them as projections suggest that emissions will continue to increase with rising temperatures, alongside the intensification of agriculture to meet global food demand. Slurry acidification in-house can reduce these emissions. In this study, an acidification technology was installed in a pig-fattening barn to evaluate the influence of the addition of a mixture of organic acids, mainly lactic acid and glycolic acid, on NH₃ and GHG emissions. A total of 384 pigs were allocated to four experimental rooms, two with additive applied to the slurry pits by a spraying system and two as a control. In high-temperature conditions, the spraying system discharged additive over the slurry which, in contrast with other systems, was stored inside the rooms during the whole trial. The concentration of NH₃ and GHG, the temperature, and the air extraction rate were measured continuously. A significant reduction in the emissions of the gases evaluated was achieved. NH₃ emissions were reduced by 26.8%, CH₄ by 23.6%, N₂O by 25.0%, and CO₂ by 28.7%. The role of the dynamic spraying system is considered essential to prevent the acidification effect being reversed by the buffering effect of the slurry itself. Full article

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18 pages, 1268 KiB

Open AccessArticle

An Optimistic Vision for Public Transport in Bucharest City After the Bus Fleet Upgrades

by Anca-Florentina Popescu, Ecaterina Matei, Alexandra Bădiceanu, Alexandru Ioan Balint, Maria Râpă, George Coman and Cristian Predescu

Environments 2025, 12(7), 242; https://doi.org/10.3390/environments12070242 - 15 Jul 2025

Viewed by 209

Abstract

Air pollution caused by CO₂ emissions has become a global issue of vital importance, posing irreversible risks to health and life when concentration of CO₂ becomes too high. This study aims to estimate the CO₂ emissions and carbon footprint of [...] Read more.

Air pollution caused by CO₂ emissions has become a global issue of vital importance, posing irreversible risks to health and life when concentration of CO₂ becomes too high. This study aims to estimate the CO₂ emissions and carbon footprint of the public transport bus fleet in Bucharest, with a comparative analysis of greenhouse gas (GHG) emissions generated by diesel and electric buses of the Bucharest Public Transport Company (STB S.A.) in the period 2021–2024, after the modernization of the fleet through the introduction of 130 hybrid buses and 58 electric buses. In 2024, the introduction of electric buses and the reduction in diesel bus mileage reduced GHG emissions by almost 13% compared to 2023, saving over 11 kilotons of CO_2e. There was also a 2.68% reduction in the specific carbon footprint compared to the previous year, which is clear evidence of the potential of electric vehicles in achieving decarbonization targets. We have also developed two strategies, one for 2025 and one for the period 2025–2030, replacing the aging fleet with electric vehicles. This demonstrates the relevance of electric transport integrated into the sustainable development strategy for urban mobility systems and alignment with European standards, including improving air quality and living standards. Full article

(This article belongs to the Special Issue Air Pollution in Urban and Industrial Areas III)

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20 pages, 5384 KiB

Open AccessArticle

Integrated Water Resources Management in Response to Rainfall Change: A Runoff-Based Approach for Mixed Land-Use Catchments

by Jinsun Kim and Ok Yeon Choi

Environments 2025, 12(7), 241; https://doi.org/10.3390/environments12070241 - 14 Jul 2025

Viewed by 235

Abstract

The U.S. Environmental Protection Agency (EPA) developed the concept of Water Quality Volume (WQv) as a Best Management Practice (BMP) to treat the first 25.4 mm of rainfall in urban areas, aiming to capture approximately 90% of annual runoff. However, applying this urban-based [...] Read more.

The U.S. Environmental Protection Agency (EPA) developed the concept of Water Quality Volume (WQv) as a Best Management Practice (BMP) to treat the first 25.4 mm of rainfall in urban areas, aiming to capture approximately 90% of annual runoff. However, applying this urban-based standard—designed for areas with over 50% imperviousness—to rural regions with higher infiltration and pervious surfaces may result in overestimated facility capacities. In Korea, a uniform WQv criterion of 5 mm is applied nationwide, regardless of land use or hydrological conditions. This study examines the suitability of this 5 mm standard in rural catchments using the Hydrological Simulation Program–Fortran (HSPF). Eight sub-watersheds in the target area were simulated under varying cumulative runoff depths (1–10 mm) to assess pollutant loads and runoff characteristics. First-flush effects were most evident below 5 mm, with variation depending on land cover. Nature-based treatment systems for constructed wetlands were modeled for each sub-watershed, and their effectiveness was evaluated using Flow Duration Curves (FDCs) and Load Duration Curves (LDCs). The findings suggest that the uniform 5 mm WQv criterion may result in overdesign in rural watersheds and highlight the need for region-specific standards that consider local land-use and hydrological variability. Full article

(This article belongs to the Special Issue Monitoring of Contaminated Water and Soil)

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16 pages, 3973 KiB

Open AccessArticle

Toxicological Risk Assessment and Source Identification of Groundwater Pollution: A Case of Sheep Herd Damage in a Pastoral Area

by Wei Wang, Honger Cheng, Yuewei Yang, Jianjun Su, Jialu Sun, Xiaojing Li and Qian Zhao

Environments 2025, 12(7), 240; https://doi.org/10.3390/environments12070240 - 14 Jul 2025

Viewed by 192

Abstract

Improper emissions from industrial activities pose toxicological risks to groundwater safety. Based on an environmental forensic identification case involving livestock (sheep) damage caused by groundwater pollution in a pastoral area, we comprehensively evaluated groundwater quality risks, toxicological risks, and pollution sources using multivariate [...] Read more.

Improper emissions from industrial activities pose toxicological risks to groundwater safety. Based on an environmental forensic identification case involving livestock (sheep) damage caused by groundwater pollution in a pastoral area, we comprehensively evaluated groundwater quality risks, toxicological risks, and pollution sources using multivariate statistical methods, the Nemerow index method, and a non-carcinogenic health risk model. The potential specific pollutants in the region mainly included calcium, potassium, sodium, magnesium, manganese, fluoride, chloride, sulfate, ammonia nitrogen, total dissolved solids, and nitrate. An evaluation of the groundwater health risk factors showed that fluoride, nitrate, and manganese pose higher health risks (HQ > 1), as fluoride > nitrate > manganese. This suggests that these three pollutants were the primary causes of livestock damage. Identification of pollution sources using multivariate statistical analysis revealed that the main pollutants in the groundwater originate from two rare earth enterprises in the surrounding industrial park, followed by the emissions from animal husbandry. This study provides guidelines into comprehensive regional toxicological risk assessment and source tracing, offering an identification method for similar forensic environmental damage cases. Full article

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18 pages, 7163 KiB

Open AccessArticle

Saline Water Stress in Caatinga Species with Potential for Reforestation in the Face of Advancing Desertification in the Brazilian Semiarid Region

by Márcia Bruna Marim de Moura, Tays Ferreira Barros, Thieres George Freire da Silva, Wagner Martins dos Santos, Lady Daiane Costa de Sousa Martins, Elania Freire da Silva, João L. M. P. de Lima, Xuguang Tang, Alexandre Maniçoba da Rosa Ferraz Jardim, Carlos André Alves de Souza, Klébia Raiane Siqueira de Souza and Luciana Sandra Bastos de Souza

Environments 2025, 12(7), 239; https://doi.org/10.3390/environments12070239 - 14 Jul 2025

Viewed by 251

Abstract

The advance of the soil desertification process and water salinisation hinders reforestation actions in the Brazilian semiarid region due to the negative effects on the initial establishment of seedlings. Knowledge of potential species for overcoming the problems of soil and water salinity is [...] Read more.

The advance of the soil desertification process and water salinisation hinders reforestation actions in the Brazilian semiarid region due to the negative effects on the initial establishment of seedlings. Knowledge of potential species for overcoming the problems of soil and water salinity is of broad interest. This study evaluated the growth of seedlings of the species Handroanthus impetiginosus and Handroanthus spongiosus subjected to the combined stresses of salinity and water deficit. The species were subjected to three water depths (WDs): WD1—50%, WD2—75% and WD3—100% of reference evapotranspiration, and four salinity levels (SL): SL1—0.27 dS m⁻¹, SL2—2.52 dS m⁻¹, SL3—6.35 dS m⁻¹ and SL4—7.38 dS m⁻¹. Biometric data, including plant height, number of leaves, collar diameter and biomass, was obtained. The results showed that H. impetiginosus was more tolerant of the conditions analysed. The species showed greater sensitivity to salt stress, which reduced growth and dry biomass accumulation by up to 98%. Increased water deficit reduced height, collar diameter, number of leaves, root biomass and total biomass. We propose that the optimal water depth for both species is 100% of the reference evapotranspiration. Full article

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21 pages, 1908 KiB

Open AccessArticle

Energy Footprints, Energy Sufficiency, and Human Well-Being in Iceland

by Kevin Joseph Dillman, Anna Kristín Einarsdóttir, Marta Rós Karlsdóttir and Jukka Heinonen

Environments 2025, 12(7), 238; https://doi.org/10.3390/environments12070238 - 11 Jul 2025

Viewed by 370

Abstract

In the intersecting field of energy consumption and human well-being, many macro-level studies link national energy use with well-being. These studies often rely on aggregate data, however, limiting insights into intra-national inequities and diverse well-being outcomes. To bridge this gap, this study used [...] Read more.

In the intersecting field of energy consumption and human well-being, many macro-level studies link national energy use with well-being. These studies often rely on aggregate data, however, limiting insights into intra-national inequities and diverse well-being outcomes. To bridge this gap, this study used a single Nordic survey that allowed for the calculation of consumption-based energy footprints alongside well-being measures, focusing on Icelandic participants. A factor analysis of well-being responses identifies four factors: Eudaimonic, Financial, Housing/Local, and Health-related well-being. We found that well-being in Iceland largely remains decoupled from energy footprints across income and consumption groups, except for financial well-being. However, these groups differ significantly in consumption lifestyles and associated footprints, with only a small fraction of consumers maintaining energy use within global sufficiency thresholds. Most exceed these levels, suggesting that Iceland could reduce energy consumption without significantly harming well-being. Future research should explore strategies to lower consumption without triggering negative social reactions or declines in well-being. Full article

(This article belongs to the Special Issue Balancing Energy and Environmental Sustainability: Innovations, Impacts, and Pathways)

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21 pages, 6165 KiB

Open AccessArticle

Hydrological Transformation and Societal Perception of Urban Pluvial Flooding in a Karstic Watershed: A Case Study from the Southern Mexican Caribbean

by Cristina C. Valle-Queb, David G. Rejón-Parra, José M. Camacho-Sanabria, Rosalía Chávez-Alvarado and Juan C. Alcérreca-Huerta

Environments 2025, 12(7), 237; https://doi.org/10.3390/environments12070237 - 10 Jul 2025

Viewed by 708

Abstract

Urban pluvial flooding (UPF) is an increasingly critical issue due to rapid urbanization and intensified precipitation driven by climate change that yet remains understudied in the Caribbean. This study analyzes the effects of UPF resulting from the transformation of a natural karstic landscape [...] Read more.

Urban pluvial flooding (UPF) is an increasingly critical issue due to rapid urbanization and intensified precipitation driven by climate change that yet remains understudied in the Caribbean. This study analyzes the effects of UPF resulting from the transformation of a natural karstic landscape into an urbanized area considering a sub-watershed in Chetumal, Southern Mexican Caribbean, as a case study. Hydrographic numerical modeling was conducted using the IBER 2.5.1 software and the SCS-CN method to estimate surface runoff for a critical UPF event across three stages: (i) 1928—natural condition; (ii) 1998—semi-urbanized (78% coverage); and (iii) 2015—urbanized (88% coverage). Urbanization led to the orthogonalization of the drainage network, an increase in the sub-watershed area (20%) and mainstream length (33%), flow velocities rising 10–100 times, a 52% reduction in surface roughness, and a 32% decrease in the potential maximum soil retention before runoff occurs. In urbanized scenarios, 53.5% of flooded areas exceeded 0.5 m in depth, compared to 16.8% in non-urbanized conditions. Community-based knowledge supported flood extent estimates with 44.5% of respondents reporting floodwater levels exceeding 0.50 m, primarily in streets. Only 43.1% recalled past flood levels, indicating a loss of societal memory, although risk perception remained high among directly affected residents. The reported UPF effects perceived in the area mainly related to housing damage (30.2%), mobility disruption (25.5%), or health issues (12.9%). Although UPF events are frequent, insufficient drainage infrastructure, altered runoff patterns, and limited access to public shelters and communication increased vulnerability. Full article

(This article belongs to the Special Issue Hydrological Modeling and Sustainable Water Resources Management, 2nd Edition)

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40 pages, 6079 KiB

Open AccessArticle

Stream Community Metabolism and Dissolved-Oxygen Dynamics: Where Did the Oxygen Come From?

by James N. McNair and Jay R. Zuidema

Environments 2025, 12(7), 236; https://doi.org/10.3390/environments12070236 - 10 Jul 2025

Viewed by 365

Abstract

Stream metabolism is traditionally defined as the combined metabolism of all aerobic organisms in a stream. Its component processes of oxygenic photosynthesis and aerobic respiration create and consume dissolved oxygen (DO) and therefore can be measured using time series of DO concentration, solar [...] Read more.

Stream metabolism is traditionally defined as the combined metabolism of all aerobic organisms in a stream. Its component processes of oxygenic photosynthesis and aerobic respiration create and consume dissolved oxygen (DO) and therefore can be measured using time series of DO concentration, solar radiation, and water temperature, in conjunction with a model of DO dynamics that includes photosynthesis, respiration, and oxygen exchange with the atmosphere. A complication is that stream communities typically exhibit pronounced longitudinal heterogeneity in habitat type (e.g., shaded versus unshaded reaches) and species composition and abundance. The influence of a given stream reach and associated community on DO concentration propagates downstream with the current, gradually being replaced, over a transition zone, by the influence of the next downstream reach. Knowing the approximate length of this transition zone is important when estimating stream metabolism with one-station DO monitoring, since it indicates which stream reach and associated community the metabolism estimates apply to. We propose new methods for estimating the transition-zone length and for estimating the proportions of DO at a given location in a stream reach that entered the reach from upstream, from photosynthesis within the reach, and from atmospheric uptake within the reach. We also propose methods for estimating the residence-time distribution of DO present at a given stream location, and the corresponding distribution of upstream distances at which the DO entered the stream. Both distributions are approximately exponential. Thus, habitat immediately upstream of the sonde has the greatest influence on metabolism estimates with one-station monitoring, and it is therefore important to place the sonde so this habitat is representative of the study reach. Full article

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28 pages, 4718 KiB

Open AccessArticle

Analysis and Prospective Use of Local Mineral Raw Materials to Increase the Aesthetic and Recreational Value of the Vyzhyvka River (Western Ukraine)

by Yuliia Trach, Tetiana Tkachenko, Maryna Kravchenko, Viktor Mileikovskyi, Oksana Tsos, Mariia Boiaryn, Olha Biedunkova, Roman Trach and Ihor Statnyk

Environments 2025, 12(7), 235; https://doi.org/10.3390/environments12070235 - 10 Jul 2025

Viewed by 427

Abstract

Macrophytes are important components of aquatic ecosystems performing essential ecological functions. Their species composition and density reflect the ecological status of water bodies. The optimal ratio of morphological types of macrophytes is an important condition for preventing eutrophication. The aim of the study [...] Read more.

Macrophytes are important components of aquatic ecosystems performing essential ecological functions. Their species composition and density reflect the ecological status of water bodies. The optimal ratio of morphological types of macrophytes is an important condition for preventing eutrophication. The aim of the study is to analyse the species composition, distribution, and density of macrophytes in the Vyzhyvka River (Ukraine) in a seasonal aspect (2023–2024) under constant physical and chemical characteristics of water. To assess the seasonal dynamics of water quality, changes in indicators in three representative areas were analysed. The MIR method of environmental indexation of watercourses was used to assess the ecological state of the river. The water quality in the Vyzhyvka River at all test sites corresponds to the second class of the “good” category with the trophic status of “mesotrophic”. This is confirmed by the identified species diversity, which includes 64 species of higher aquatic and riparian plants. Among the various morphological types of macrophytes, submerged rooted forms account for only 10.56% of the total species composition. To ensure a functional balance between submerged and other forms of macrophytes, a scientifically based approach is proposed, which involves the use of mineral raw materials of local origin, in particular, mining and quarrying wastes rich in silicon, calcium and other mineral components. The results obtained are of practical value for water management, environmental protection, and ecological reclamation and can be used to develop effective measures to restore river ecosystems. Full article

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14 pages, 1811 KiB

Open AccessReview

Epigenetic Modifications and Gene Expression Alterations in Plants Exposed to Nanomaterials and Nanoplastics: The Role of MicroRNAs, lncRNAs and DNA Methylation

by Massimo Aloisi and Anna Maria Giuseppina Poma

Environments 2025, 12(7), 234; https://doi.org/10.3390/environments12070234 - 10 Jul 2025

Viewed by 372

Abstract

Nanomaterials (NMs) are currently widely used in a wide range of industrial production and scientific applications, starting from molecular and medical diagnostics to agriculture. In the agricultural and food systems, NMs are now used in various ways, to improve the nutritional value of [...] Read more.

Nanomaterials (NMs) are currently widely used in a wide range of industrial production and scientific applications, starting from molecular and medical diagnostics to agriculture. In the agricultural and food systems, NMs are now used in various ways, to improve the nutritional value of crops, detect microbial activity and inhibit biofilms, encapsulate and deliver pesticides, protect plants from chemical spoilage, as nanosensors and more. Despite these applications, NMs are described as “dual-face technologies”: they can also act as environmental contaminants. For instance, nanoplastics (NPs) dispersed in the environment can damage plants at different levels and undermine their viability. Epigenetic modifications induced by NMs have potentially wider and longer-term impacts on gene expression and plant functions. Therefore, it is important to verify whether plants are also affected by NMs on the molecular level, including epigenetic mechanisms and any induced variation on the epigenome. This review focusses on gene expression modulation and epigenetic alterations such as DNA methylation and the role of microRNAs and long non-coding RNAs (lncRNAs) induced in plants and crops by NMs and NPs. Full article

(This article belongs to the Special Issue Environmental Pollution Risk Assessment)

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36 pages, 4816 KiB

Open AccessArticle

Inactivation of Continuously Released Airborne Virus by Upper-Room UVC LED Irradiation Under Realistic Testing Conditions

by Andreas Schmohl, Anna Nagele-Renzl and Michael Buschhaus

Environments 2025, 12(7), 233; https://doi.org/10.3390/environments12070233 - 9 Jul 2025

Viewed by 489

Abstract

Ultraviolet (UV) radiation can be used to inactivate microorganisms, with upper-room UV germicidal irradiation (UR-UVGI) representing a promising approach. This study investigated the inactivation of the airborne surrogate virus Phi6 by a UR-UVGI system based on light-emitting diodes (LEDs) in a realistic test [...] Read more.

Ultraviolet (UV) radiation can be used to inactivate microorganisms, with upper-room UV germicidal irradiation (UR-UVGI) representing a promising approach. This study investigated the inactivation of the airborne surrogate virus Phi6 by a UR-UVGI system based on light-emitting diodes (LEDs) in a realistic test setup. Two test scenarios were used, one with continuous Phi6 release, simulating a source located in the room and leading to a dynamic equilibrium, and the second simulating a situation in which the source has left the room and an exponential decay is evaluated. The “Incremental Evaluation Model” was adapted and used to evaluate the dynamic equilibrium measurement. At a position in the breathing direction 5 m away from the Phi6 source, the loss coefficient (air exchange rate) was 25 h⁻¹ in the first scenario and 30 h⁻¹ in the second. These results show that UR-UVGI systems can effectively inactivate microorganisms. However, at 1 m distance from the Phi6 source perpendicular to the breathing direction, only minimal inactivation was observed due to short-circuit airflow. At this position, the loss coefficient was <2 h⁻¹ in the first scenario and 17 h⁻¹ in the second scenario, indicating that short-circuit airflows can only be detected by dynamic equilibrium measurements. Full article

(This article belongs to the Special Issue Editorial Board Members' Collection Series: Air Quality Assessment and Management, 2nd Edition)

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19 pages, 290 KiB

Open AccessArticle

Assessment of Greenhouse Gas Emissions and Carbon Footprint in Mountainous Semi-Extensive Dairy Sheep and Goat Farms in Greece

by George P. Laliotis and Iosif Bizelis

Environments 2025, 12(7), 232; https://doi.org/10.3390/environments12070232 - 9 Jul 2025

Viewed by 379

Abstract

Livestock contributes to global warming through greenhouse gas (GHG) emissions. Reducing these emissions is an ongoing challenge for the small ruminant sector. Despite its significant role in national economies, limited studies on the carbon footprint (CF) of dairy small ruminants in Mediterranean countries [...] Read more.

Livestock contributes to global warming through greenhouse gas (GHG) emissions. Reducing these emissions is an ongoing challenge for the small ruminant sector. Despite its significant role in national economies, limited studies on the carbon footprint (CF) of dairy small ruminants in Mediterranean countries exist. The study aimed to achieve the following: (a) estimate the GHG emissions of eleven semi-extensive sheep and goat farms in a mountainous region of southern Greece, using the Tier 1 and Tier 2 methodologies; (b) compare the outcomes of both methods; and (c) calculate farms’ CF, as a means of their environmental impact evaluation. All on-farm activities (except machinery or medicine use) related to sheep or goat production were considered to estimate GHG emissions. The results show differences between Tier 1 and Tier 2 estimates, reflecting the simplified computational approach of Tier 1. The average CF values estimated via Tier 1 for goat and sheep farms were 2.12 and 2.87 kg CO₂-eq./kg FPCM, respectively. Using Tier 2, these values increased to 2.73 and 3.99 kg CO₂-eq./kg FPCM. To mitigate environmental impact, farms could enhance productivity by improving herd management and feeding strategies. Full article

13 pages, 620 KiB

Open AccessArticle

Assessing Environmental Risk Posed by Pharmaceuticals and Personal Care Products in Shallow Lakes, Florida, USA—Part B

by Elzbieta Bialkowska-Jelinska, Philip van Beynen and Laurent Calcul

Environments 2025, 12(7), 231; https://doi.org/10.3390/environments12070231 - 8 Jul 2025

Viewed by 476

Abstract

The use of pharmaceuticals and personal care products (PPCPs) is steadily growing as the world’s population both increases and ages. Many of these products are released into the environment via municipal wastewater treatment plants and onsite wastewater treatment systems (septic tanks). Consequently, it [...] Read more.

The use of pharmaceuticals and personal care products (PPCPs) is steadily growing as the world’s population both increases and ages. Many of these products are released into the environment via municipal wastewater treatment plants and onsite wastewater treatment systems (septic tanks). Consequently, it is essential to ascertain whether these contaminants pose any risk to aquatic organisms who live in the water bodies receiving this waste. Risk quotients (RQ) are a commonly used method to do so. For our pilot study, we undertook such analysis for three trophic levels: algae, crustaceans, and fish from two small lakes, one fed by septic tanks and the other not. This research was conducted in 2021 from the end of the dry season and through most of the wet season in west central Florida, USA. Of the 14 PPCPs measured, six had RQs that posed a risk to all three trophic levels. This risk increased during the wet season. Both lakes, regardless of whether they directly received PPCPs from septic tanks or not, had some level of risk. However, the lake without septic tanks had a smaller risk, both in elevated RQs and the occurrence to the various species. Of the PPCPs measured, DEET, caffeine, and theophylline posed the greatest risk. Full article

(This article belongs to the Special Issue Research Progress in Groundwater Contamination and Treatment)

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Graphical abstract

7 pages, 170 KiB

Open AccessEditorial

Environments: Enhancing Diversity of Environmental Systems: Nature as a Shared Wealth, Not a Commodity

by Sergio Ulgiati

Environments 2025, 12(7), 230; https://doi.org/10.3390/environments12070230 - 7 Jul 2025

Viewed by 404

Abstract

The biosphere (as the habitat of all species, including humans) and its self-organization, to provide deep interactions and support biodiversity, require full understanding and appropriate environmental policy making [...] Full article

31 pages, 859 KiB

Open AccessReview

A Review of Persistent Soil Contaminants: Assessment and Remediation Strategies

by António Alberto S. Correia and Maria Graça Rasteiro

Environments 2025, 12(7), 229; https://doi.org/10.3390/environments12070229 - 5 Jul 2025

Viewed by 780

Abstract

The presence of persistent contaminants in soils is of growing concern around the world. Contaminated soils can affect numerous ecological environments and lead to significant health risks to humans, affecting soil biodiversity, structure and geomechanical behaviour and agricultural sustainability. Additionally, soil contaminants can [...] Read more.

The presence of persistent contaminants in soils is of growing concern around the world. Contaminated soils can affect numerous ecological environments and lead to significant health risks to humans, affecting soil biodiversity, structure and geomechanical behaviour and agricultural sustainability. Additionally, soil contaminants can also leach into water flows, which is another concern. In general, soil contamination can be attributed to natural sources or to anthropogenic sources associated with human activity. Soil contaminants are usually classified in the following categories: biological, radioactive, organic and inorganic contaminants. State of the art information regarding some of the most common persistent soil contaminants, including possible sources and prevalence, and monitoring approaches and information about their effects on soil characteristics, including usability, as well as information on possible mobility to other environmental media is presented in this review paper. Finally, a comprehensive overview of remediation strategies which are being developed, including the more traditional ones as well as novel strategies that have been proposed lately by the scientific community, is provided. This includes physicochemical and biological technologies, as well as mixed remediation technologies aimed at enhancing remediation efficiency. Full article

(This article belongs to the Special Issue Monitoring of Contaminated Water and Soil)

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19 pages, 1851 KiB

Open AccessArticle

Industrial-Scale Wastewater Nano-Aeration and -Oxygenation and Dissolved Air Flotation: Electric Field Nanobubble and Machine Learning Approaches to Enhanced Nano-Aeration and Flotation

by Niall J. English

Environments 2025, 12(7), 228; https://doi.org/10.3390/environments12070228 - 5 Jul 2025

Viewed by 536

Abstract

Substantial boosts in the low-energy nano-oxygenation of incoming process water were achieved at a municipal wastewater treatment plant (WWTP) upstream of activated sludge (AS) aeration lanes on a single-pass basis by means of an electric field nanobubble (NB) generation method (with unit residence [...] Read more.

Substantial boosts in the low-energy nano-oxygenation of incoming process water were achieved at a municipal wastewater treatment plant (WWTP) upstream of activated sludge (AS) aeration lanes on a single-pass basis by means of an electric field nanobubble (NB) generation method (with unit residence times of the order of just 10–15 s). Both ambient air and O₂ cylinders were used as gas sources. In both cases, it was found that the levels of dissolved oxygen (DO) were maintained far higher for much longer than those of conventionally aerated water in the AS lane—and at DO levels in the optimal operational WWTP oxygenation zone of about 2.5–3.5 mg/L. In the AS lanes themselves, there were also excellent conversions to nitrate from nitrite, owing to reactive oxygen species (ROS) and some improvements in BOD and E. coli profiles. Nanobubble-enhanced Dissolved Air Flotation (DAF) was found to be enhanced at shorter times for batch processes: settlement dynamics were slowed slightly initially upon contact with virgin NBs, although the overall time was not particularly affected, owing to faster settlement once the recruitment of micro-particulates took place around the NBs—actually making density-filtering ultimately more facile. The development of machine learning (ML) models predictive of NB populations was carried out in laboratory work with deionised water, in addition to WWTP influent water for a second class of field-oriented ML models based on a more narrow set of more easily and quickly measured data variables in the field, and correlations were found for a more facile prediction of important parameters, such as the NB generation rate and the particular dependent variable that is required to be correlated with the efficient and effective functioning of the nanobubble generator (NBG) for the task at hand—e.g., boosting dissolved oxygen (DO) or shifting Oxidative Reductive Potential (ORP). Full article

(This article belongs to the Special Issue Advanced Catalytic Processes and Nanomaterials for Environmental Remediation)

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23 pages, 6122 KiB

Open AccessArticle

Decoding Salinization Dynamics in Mediterranean Coastal Aquifers: A Case Study from a Wetland in Southern Italy

by Giuseppe Passarella, Rita Masciale, Matia Menichini, Marco Doveri and Ivan Portoghese

Environments 2025, 12(7), 227; https://doi.org/10.3390/environments12070227 - 2 Jul 2025

Viewed by 466

Abstract

This study investigates the salinization processes affecting the coastal aquifer within the Torre Guaceto State Nature Reserve, a Mediterranean coastal area characterized by a unique ecological value of a brackish wetland threatened by water-intensive agricultural activities. Groundwater salinization threatens biodiversity, agriculture, and water [...] Read more.

This study investigates the salinization processes affecting the coastal aquifer within the Torre Guaceto State Nature Reserve, a Mediterranean coastal area characterized by a unique ecological value of a brackish wetland threatened by water-intensive agricultural activities. Groundwater salinization threatens biodiversity, agriculture, and water resource sustainability. This work integrates hydrogeological monitoring, geochemical and isotopic analyses, and geophysical surveys to understand salinity dynamics and identify key drivers, such as seawater intrusion, irrigation practices, and climate change. Data collected during monitoring campaigns from 2022 to 2024 reveal significant seasonal and spatial variations in groundwater salinity influenced by natural and human-induced factors. The results indicate that salt recycling from irrigation and marine spray deposition are important local contributors to groundwater salinity, in addition to seawater intrusion. These findings highlight the urgent need for integrated groundwater management approaches considering the combined effects of agricultural practices, irrigation water quality, and climate variability tailored to Mediterranean coastal ecosystems. Full article

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30 pages, 6809 KiB

Open AccessArticle

Laminaria digitata Supplementation as a Climate-Smart Strategy to Counteract the Interactive Effects of Marine Heatwaves and Disease Outbreaks in Farmed Gilthead Seabream (Sparus aurata)

by Isa Marmelo, Tomás Chainho, Daniel Bolotas, Alícia Pereira, Busenur Özkan, Cátia Marques, Iris A. L. Silva, Florbela Soares, Pedro Pousão-Ferreira, Elsa F. Vieira, Cristina Delerue-Matos, Zélia Silva, Paula A. Videira, Tiago Repolho, Mário Sousa Diniz, António Marques and Ana Luísa Maulvault

Environments 2025, 12(7), 226; https://doi.org/10.3390/environments12070226 - 30 Jun 2025

Viewed by 630

Abstract

Extreme weather events, such as marine heatwaves (MHWs), pose serious threats to the aquaculture sector, facilitating the occurrence of disease outbreaks and compromising farmed animals’ welfare and survival. Hence, finding eco-innovative strategies to improve animal immunocompetence is essential to assure aquaculture’s sustainability and [...] Read more.

Extreme weather events, such as marine heatwaves (MHWs), pose serious threats to the aquaculture sector, facilitating the occurrence of disease outbreaks and compromising farmed animals’ welfare and survival. Hence, finding eco-innovative strategies to improve animal immunocompetence is essential to assure aquaculture’s sustainability and resilience in a rapidly changing ocean. This study evaluated the immunostimulatory potential of Laminaria digitata powder (0.3% and 1.5%) and extract (0.3%) in juvenile gilthead seabream (Sparus aurata) exposed to a Vibrio harveyi outbreak during a Category III MHW event (T = 25.7 °C). Overall, L. digitata supplementation did not significantly affect fish immunocompetence under optimal rearing conditions (T = 21.4 °C; no infection), nor did it induce any adverse effects. However, both the powder (1.5%) and extract (0.3%) forms of L. digitata supplementation effectively mitigated the negative impacts prompted by the MHW and Vibrio harveyi infection—evidenced by improvements in fish health indicators, hematological parameters, leukocyte viability, granulocyte proportions, and reductions in peroxidase activity and immunoglobulin M levels. From an economic standpoint, supplementation with 1.5% L. digitata powder emerged as the most promising strategy, offering a practical balance between effectiveness and affordability for large-scale applications. These findings highlight the potential of L. digitata as an immunostimulatory aquafeed supplement, with promising benefits for fish health and resilience under adverse rearing conditions. Full article

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4 pages, 148 KiB

Open AccessEditorial

Special Issue “Advanced Research on Micropollutants in Water”

by Cátia A. L. Graça

Environments 2025, 12(7), 225; https://doi.org/10.3390/environments12070225 - 30 Jun 2025

Viewed by 470

Abstract

The increasing occurrence of micropollutants in aquatic environments has become a global concern due to their persistence, potential toxicity, and resistance to conventional water treatment processes [...] Full article

(This article belongs to the Special Issue Advanced Research on Micropollutants in Water)

21 pages, 3740 KiB

Open AccessArticle

Mineral Condition Changes in Amended Soils and Woody Vegetation Installed on a Polluted Soil with Trace Metals in Lubumbashi (DR Congo): Results of a Four-Year Trial

by Serge Langunu, Jacques Kilela Mwanasomwe, Dieu-donné N’Tambwe Nghonda, Gilles Colinet and Mylor Ngoy Shutcha

Environments 2025, 12(7), 224; https://doi.org/10.3390/environments12070224 - 30 Jun 2025

Viewed by 584

Abstract

The use of trees to revegetate urban areas contaminated by mining activity is a low-cost, low-maintenance technique, of which the success will depend on the plant species, planting methods, and geochemical processes at the soil-plant interface. This study analyzed the evolution of mineral [...] Read more.

The use of trees to revegetate urban areas contaminated by mining activity is a low-cost, low-maintenance technique, of which the success will depend on the plant species, planting methods, and geochemical processes at the soil-plant interface. This study analyzed the evolution of mineral composition in the rooting soil, tree, and herbaceous vegetation on soils contaminated by As, Cd, Cu, Co, Pb, and Zn. An in-situ experiment was carried out in Lubumbashi (South-eastern DR Congo) with six tree species (Acacia auriculiformis, Albizia lebbeck, Delonix regia, Leucaena leucocephala, Mangifera indica, and Syzygium guineense), in 0.187 m³ pits amended with municipal compost and limestone. After planting in the amended and unamended (control) pits, soil samples were taken for chemical analysis. Eighteen months after planting, a floristic inventory was carried out to assess the spontaneous colonization of herbaceous species. The results show an increase in metal concentrations in the rooting soil between 2019 and 2023 (Cu: 725 ± 136 to 6141 ± 1853 mg kg⁻¹; As: 16.2 ± 1.4 to 95 ± 28.5 mg kg⁻¹; Cd: 2.7 ± 1.3 to 8.7 ± 2.0 mg kg⁻¹; Co: 151 ± 36.3 to 182 ± 113 mg kg⁻¹; Zn: 558 ± 418 to 1098 ± 1037 mg kg⁻¹), with a stable pH and a decrease in nutrients (P, K, Ca, and Fe). The trees planted in the amended pits showed better height and diameter growth and greater survival than the controls, reaching average heights of 8 m and a DBH of up to 22 cm four years after planting. A total of 13 spontaneous herbaceous species were recorded, with an increased abundance during the second inventory. These results confirm the effectiveness of pit amendment for the rapid revegetation of urban soils polluted by trace metals. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Soil Contamination and Remediation)

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20 pages, 17149 KiB

Open AccessArticle

Assessment of Trail Erosion Under the Impact of Tourist Traffic in the Bucegi Mountains, Romanian Carpathians

by Mihai Radu Jula and Mircea Voiculescu

Environments 2025, 12(7), 223; https://doi.org/10.3390/environments12070223 - 28 Jun 2025

Viewed by 510

Abstract

Trail erosion is a global issue, particularly in mountainous regions, that is largely driven by increased tourist flows and uncontrolled trampling. Our study was conducted in the Bucegi Mountains, Southern Carpathians, Romania, along three of the most frequented hiking trails, each with varying [...] Read more.

Trail erosion is a global issue, particularly in mountainous regions, that is largely driven by increased tourist flows and uncontrolled trampling. Our study was conducted in the Bucegi Mountains, Southern Carpathians, Romania, along three of the most frequented hiking trails, each with varying levels of difficulty. Two of these trails cross both the forest and alpine zones, and the other crosses only the alpine zone: Jepii Mici, connecting the Bușteni resort (960 m a.s.l.) to Babele Chalet (2200 m a.s.l.); Jepii Mari, linking Bușteni resort to the National Sports Complex Piatra Arsă (1960 m a.s.l.); and the trail between Babele Chalet and Omu Peak (2505 m a.s.l.). Our analysis focused on morphometric parameters, the volume of displaced soil, and associated geohazards, serving as indicators for assessing the degradation state of hiking trails and their suitability for mountain biking and tourist traffic. The findings reveal a high degree of trail degradation, highlighted by increased trail width, the development of parallel trail sections due to dispersed tourist traffic, areas with abrupt gradient changes, and sections severely affected by erosion, resulting in significant volumes of displaced soil. These factors hinder effective tourist traffic, including hiking and mountain biking, and degrade the mountainous landscape. Conversely, the results can be useful for both monitoring annual trail erosion rates and facilitating tourist access, tailored to individual and group interests, as well as the physical readiness of each tourist, to offer a more pleasurable and sustainable experience. Full article

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15 pages, 1473 KiB

Open AccessArticle

Climate Change Impacts on Agricultural Suitability in Rio Grande do Sul, Brazil

by Emma Haggerty, Ethan R. Wertlieb and Dmitry A. Streletskiy

Environments 2025, 12(7), 222; https://doi.org/10.3390/environments12070222 - 28 Jun 2025

Viewed by 561

Abstract

Changing climatic conditions are significant determinants of agricultural productivity. Rio Grande do Sul is the southernmost state and the second-largest agricultural producer in Brazil. The suitability of its land for farming can be used as a proxy for agricultural and economic success, making [...] Read more.

Changing climatic conditions are significant determinants of agricultural productivity. Rio Grande do Sul is the southernmost state and the second-largest agricultural producer in Brazil. The suitability of its land for farming can be used as a proxy for agricultural and economic success, making it a pertinent case for exploring the consequences of climate change on major crop production. The latest available climate and environmental data was used to develop an agricultural Suitability Index (SI) that quantifies the suitability of land for rice, tobacco, soybean, and corn production in 2020 (present), 2050 (near-future), and 2100 (far-future) under moderate (SSP245) and extreme (SSP585) climate scenarios. SI scores for each municipality of Rio Grande do Sul consider inputs from a three-layer framework (climatic, non-climatic, and current production) to provide critical insight into potential shifts in agricultural productivity. While terrestrial suitability for crop growth varies both spatially and temporally, widespread decreases in suitability for all four crops are expected across the state under both scenarios. Soybean is expected to be the least affected crop, and rice is the most affected crop, tied to shifting patterns in precipitation, which significantly determines suitability. Local and state governments, agribusinesses, and family producers will have to adapt to environmental challenges to ensure the provision of food, labor, and economic security. Full article

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11 pages, 497 KiB

Open AccessOpinion

Beyond Biomass: Reimagining Microalgae as Living Environmental Nano-Factories

by Thinesh Selvaratnam, Shaseevarajan Sivanantharajah and Kirusha Sriram

Environments 2025, 12(7), 221; https://doi.org/10.3390/environments12070221 - 28 Jun 2025

Viewed by 370

Abstract

Microalgae have long been recognized for their potential in biofuel production and wastewater treatment, but their broader capabilities remain underexplored. This opinion paper presents a case for a significant shift in how microalgae are conceptualized from biomass producers to dynamic, multifunctional systems that [...] Read more.

Microalgae have long been recognized for their potential in biofuel production and wastewater treatment, but their broader capabilities remain underexplored. This opinion paper presents a case for a significant shift in how microalgae are conceptualized from biomass producers to dynamic, multifunctional systems that can serve as environmental nano-factories. It highlights emerging research on the role of microalgae in heavy metal sequestration, the green biosynthesis of metal nanoparticles, and the cascading valorization of residual biomass through environmentally sustainable extraction methods. Together, these applications offer a unified platform for pollution mitigation and the production of valuable materials. The paper also examines recent progress in synthetic biology, bioreactor design, and microbial consortia that could support this transition. At the same time, it acknowledges key challenges, including issues of scalability, regulatory acceptance, and process integration. Strategic recommendations are proposed to advance this field and align it more closely with circular economy models. By reimagining microalgae as living nano-factories, this paper outlines a path forward for developing integrated, sustainable technologies that simultaneously address environmental and industrial challenges. Full article

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24 pages, 8390 KiB

Open AccessArticle

Impact of Permanent Preservation Areas on Water Quality in a Semi-Arid Watershed

by Fernanda Helena Oliveira da Silva, Fernando Bezerra Lopes, Bruno Gabriel Monteiro da Costa Bezerra, Noely Silva Viana, Isabel Cristina da Silva Araújo, Nayara Rochelli de Sousa Luna, Michele Cunha Pontes, Raí Rebouças Cavalcante, Francisco Thiago de Alburquerque Aragão and Eunice Maia de Andrade

Environments 2025, 12(7), 220; https://doi.org/10.3390/environments12070220 - 27 Jun 2025

Viewed by 470

Abstract

Water is scarce in semi-arid regions due to environmental limitations; this situation is aggravated by changes in land use and land cover (LULC). In this respect, the basic ecological functions of Permanent Preservation Areas (PPAs) help to maintain water resources. The aim of [...] Read more.

Water is scarce in semi-arid regions due to environmental limitations; this situation is aggravated by changes in land use and land cover (LULC). In this respect, the basic ecological functions of Permanent Preservation Areas (PPAs) help to maintain water resources. The aim of this study was to evaluate the relationship between the LULC and water quality in PPAs in a semi-arid watershed, from 2009 to 2016. The following limnological data were analyzed: chlorophyll-a, transparency, total nitrogen and total phosphorus. The changes in LULC were obtained by classifying images from Landsat 5, 7 and 8 into three types: Open Dry Tropical Forest (ODTF), Dense Dry Tropical Forest (DDTF) and Exposed Soil (ES). Spearman correlation and principal component analysis were applied to evaluate the relationships between the parameters. There was a significant positive correlation between DDTF and the best limnological conditions. However, ES showed a significant negative relationship with transparency and a positive relationship with chlorophyll-a, indicating a greater input of sediments and nutrients into the water. The PCA corroborated the results of the correlation. It is therefore essential to prioritize the preservation and restoration of the vegetation in these sensitive areas to ensure the sustainability of water resources. Future studies should assess the impact of specific human activities, such as agriculture, deforestation and livestock farming, on water quality in the PPAs. Full article

(This article belongs to the Special Issue Rural Landscape Management and Conservation: Advances in GIS and Remote Sensing Applications)

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Environments, Volume 12, Issue 7 (July 2025) – 40 articles

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