Ramsar wetlands, globally recognized for their ecological, hydrological, and socio-economic significance, are increasingly threatened by microplastic (MP) contamination. Despite mounting evidence of MPs in freshwater and coastal environments, no global synthesis has focused on MP contamination in Ramsar-designated wetlands. This study presents the first systematic global review of MP contamination in Ramsar wetlands by compiling peer-reviewed studies (April 2012-May 2025). This review addresses MP sources, transport pathways, contamination levels in surface water, sediment, and biota especially in threatened species, ecosystem impacts, and mitigation efforts. Key findings from quartile analysis and descriptive statistics reveal that MPs are ubiquitous across Ramsar wetland compartments, with spatial patterns showing higher contamination in Asia, North and South America, and lower levels in Europe and Australia. Certain countries' Ramsar wetlands consistently emerged as hotspots across all three environmental compartments, surface water, sediments, and biota, including Ecuador, China, India, and Ghana. Temporal trends indicate rising MP loads over the past decade, and seasonal peaks linked to runoff in some regions. Polyethylene and polypropylene were the most common polymers (> 80%), with fibres and fragments as the predominant morphotypes. Sediments generally harboured the highest MP concentrations, while biota exhibited variable uptake. These results underscore an urgent need for standardized monitoring methods and more geographically balanced research, especially in under-studied regions such as Africa and South America, to enable robust global comparisons. We recommend prioritizing plastic source reduction, enhancing international collaboration, and integrating MP pollution control into wetland conservation policies to safeguard the ecological integrity of Ramsar wetlands.

Groundwater dynamics in South Florida play an important role in shaping the hydrologic balance of the region. This study investigated long-term trends in groundwater elevation, surface water stages, and their interactions across Water Conservation Areas 3A and 3B, Everglades National Park, coastal watersheds, and Florida Bay. Time series decomposition of long-term groundwater elevation (1997 to 2022) was used to identify trends, seasonal patterns, and anomalies. Analysis of groundwater elevations revealed statistically significant regime shifts defining distinct phases of decrease (2005-2015) and increase (2016-2022) associated with changes in rainfall patterns and water management. Average groundwater elevation has increased in recent years, with upstream areas showing stronger associations with surface water flow volumes, while coastal areas showed stronger correlations with sea level changes. This distinction suggests separate hydrological mechanisms for the observed trends: upstream recharge likely dominates in freshwater marshes, whereas coastal areas are associated with sea level variability. Groundwater levels in coastal areas now remain above the ground surface even during dry periods, associated with external factors such as sea level rise. The relationships between surface water stages and groundwater elevations in most parts of the study area were linear, whereas coastal regions, parts of the Water Conservation Areas 3A and 3B and northern parts of the Taylor Slough were nonlinear. In Florida Bay, sea level variability was a dominant driver of surface water variability (88.3% relative importance), while freshwater delivery through creek discharge (2.2%) and rainfall (2.6%) showed small but measurable contributions, along with groundwater elevation (2.4%) reflecting regional hydrologic conditions.

Anthropogenic expansion has intensified heavy metal pollution in aquatic ecosystems, posing a severe threat to avian biodiversity. This study utilizes bird eggshells as non-invasive biomarkers to assess lead (Pb) and cadmium (Cd) contamination in the Gandoman Wetland, Iran. During the 2023 breeding season, eggshells were collected from three species with distinct ecological roles: the common tern (Sterna hirundo), the black-necked grebe (Podiceps nigricollis), and the Eurasian coot (Fulica atra). Metal concentrations were determined using an Agilent 240FS AA atomic absorption spectrometer (Agilent Technologies, USA). The results revealed that Pb concentrations consistently exceeded Cd levels across all species, a phenomenon attributed to the ionic mimicry of Pb2+ with Ca2+ during shell mineralization. Notably, mean concentrations for both metals significantly exceeded established hazard thresholds (Pb: 4 mg/kg; Cd: 2 mg/kg) in all species. The common tern, a high-trophic level piscivore, exhibited the highest mean concentrations (Pb: 424.29 mg/kg; Cd: 23.39 mg/kg), while lower concentrations were recorded in the black-necked grebe (Pb: 174.60 mg/kg; Cd: 1.75 mg/kg) and the Eurasian coot (Pb: 44.58 mg/kg; Cd: 2.38 mg/kg). One-way ANOVA confirmed significant interspecific differences (P < 0.05), supporting the trophic level hypothesis of bioaccumulation. Pearson correlation analysis showed nonsignificant relationships between Pb and Cd, suggesting distinct pollution sources, likely industrial effluents for Pb and agricultural runoff for Cd. These findings characterize Gandoman Wetland as a high-risk environment and highlight the urgent necessity for stringent pollution control and management strategies to safeguard wetland-dependent bird populations.

Industrial emissions have historically altered terrestrial ecosystems, but their long-term effects on insect herbivores remain insufficiently understood, particularly during ecosystem recovery following emission decline. We analysed a dataset on the densities of 24 Recognisable Taxonomic Units (RTUs) of birch-feeding insects collected from 1988 to 2025 around two industrial towns in northwestern Russia previously identified as pollution hotspots. Volkhov originally hosted an aluminium smelter, and Syasstroy was home to a pulp and paper mill. Industrial emissions from these two towns formed pollution gradients that differed in pollutant composition but were originally comparable in their environmental effects, as indicated by Norway spruce vigour. A small subset of RTUs exhibited higher densities near both polluters during the high-emission years (1988-1996), and these patterns persisted until 2025, despite the subsequent reduction in emissions and apparent ecosystem recovery. Insect herbivore diversity was independent of pollution level during both high- and low-emission periods. At the same time, birch leaf quality for autumnal moth, Epirrita autumnata increased near polluters, whereas foliar damage by insects decreased. From 1988 to 2025, the densities of monitored insects showed no significant temporal trend in sites with any pollution levels. Our results demonstrate that moderate industrial pollution has limited and taxon- or guild-specific effects on insect herbivore communities, which often show inconsistencies between polluters and among the study years. Furthermore, substantial emission reductions do not produce long-term trends in the abundance of birch-feeding insects. These findings challenge the putative role of industrial pollution as a major driver of insect decline.

Legacy pollutants continue to be detected in wildlife and ecosystems, even decades after regulatory action. The study provides the first comprehensive assessment of polychlorinated biphenyls (PCB congeners 28, 52, 101, 138, 153, 180) and chlorinated pesticides, including hexachlorobenzene (HCB), hexachlorocyclohexane (HCH), and dichlorodiphenyltrichloroethane (DDT) and its metabolites in Black-headed Gull (Chroicocephalus ridibundus) eggs from the southern Baltic Sea, covering the largest breeding colonies between Germany and Poland. Sampling was conducted over 2 consecutive years. All eggs (n = 60) contained DDT and its metabolites and PCB congeners above the reporting level, with mean total PCB concentrations of 0.135-0.268 mg/kg and mean total DDT concentrations of 0.42-0.63 mg/kg. HCB was quantified at low levels (0.01-0.02 mg/kg) in five eggs, which does not allow conclusions about site-specific sources. HCH was not quantified in any sample. No relationships were found between contaminant concentrations and biometric parameters. The consistent occurrence and concentrations of PCBs and DDT metabolites highlight the enduring environmental relevance of these substances. Acute toxic effects were not directly assessed in this study; only associations with measured endpoints were evaluated. Our findings provide crucial new baseline data for the Baltic Sea region and reinforce the value of Black-headed Gull eggs as bioindicators of legacy and chemical exposure.

Internal exposure to ionising radiation occurs predominantly through the consumption of contaminated crops, and evaluating soil-to-plant radionuclide transfer is essential for radiological risk assessment. This study investigated radionuclide activity concentrations, soil-to-plant concentration ratios (CRs), and the potential annual effective dose from food ingestion in a semiarid agricultural region. High-resolution alpha- and gamma-spectrometry (HPGe) was used to quantify 210Po, 234Th, 226Ra, 228Th, 228Ra, 210Pb, 40 K, and 137Cs in soil and in commonly consumed crops, including coriander, red pepper, potato, onion, pomegranate, cardoon, beet, tomato, and eggplant. The soil activities ranged from 16.37 to 39.59, 6.21 to 29.15, 4.84 to 26.26, 9.37 to 46.04, 10.10 to 51.04, 5.92 to 31.39, 107.21 to 434.20, and 1.15 to 2.98 Bq/kg for 210Po,234Th, 226Ra, 228Th, 228Ra, 210Pb, 40 K, and 137Cs, respectively. In plants, activity concentrations were generally lower, varying between 0.12-4.76 Bq/kg for 210Po, 0.36-5.89 Bq/kg for 226Ra, 0.22-1.61 Bq/kg for 228Th, and 386.33-3265.53 Bq/kg for 40 K, whereas 234Th, 228Ra, 210Pb, and 137Cs were mostly below the detection limits. The concentration ratios ranged from 0.01-0.14 for 210Po, 0.02-0.43 for 226Ra, 0.01-0.17 for 228Th, and 1.02-20.03 for 40 K, with elevated values observed in cardoon and eggplant. Correlation analysis highlighted strong interrelationships among radionuclides and demonstrated that transfer processes are controlled by soil physicochemical properties, particularly organic matter content, cation exchange capacity, and exchangeable cations. In contrast, carbonate content and salinity tend to restrict radionuclide mobility. These findings enhance understanding of radionuclide behaviour under semiarid climatic conditions and support improved radiological risk assessment and environmental protection strategies.

Groundwater uranium (U) prevalence in Punjab potentially threatens human health, with increasing incidence of kidney ailments, and other issues. Different aspects of U contamination have been thoroughly investigated in the region; however, a simple and cost-effective approach for the early detection of U at the local scale is lacking. Consequently, we aim to develop reliable and efficient predictive equations using commonly measured water quality parameters. The Generalized Additive Model (GAM) and Logistic Regression (LR) were adopted to model continuous U levels and categorical U class (for U30: Class 1 (U > 30 µg/L) and Class 0 (U ≤ 30 µg/L), and similarly for U60: Class 1 (U > 60 µg/L) and Class 0 (U ≤ 60 µg/L)), respectively. The adjusted R2 and deviance explained for multivariate GAM are 0.73 and 75.7%, respectively, with TDS-HCO3¯, TDS-Na+, and HCO3¯-Na+ as significant interacting pairs. Groundwater U increased with the increase of HCO3¯ and Na+ above 400-600 mg/L and TDS at 1000-1500 mg/L. This shows that greater ionic strength, excess desorption from mineral surfaces, and uranyl-carbonate complexation facilitated U enrichment in the region. The stepwise LR performed exceptionally for both U30 and U60, achieving accuracies of 94% and 96%, respectively. The resulting predictive equations are P U 30 = 1 / 1 + e - [ - 32.10 + 6.72 ( l o g 10 _ T D S ) + 1.20 ( l o g 10 _ N a ) + 1.57 ( l o g 10 _ K ) + 1.19 ( l o g 10 _ M g ) + 1.05 ( p H ) ]  and P U 60 = 1 / 1 + e - [ - 39.42 + 7.32 ( l o g 10 _ T D S ) + 1.40 ( l o g 10 _ N a ) + 1.27 ( l o g 10 _ N O 3 ) + 1.99 ( p H ) ] . The equations were cross-validated using an independent dataset, achieving more than 80% accuracy, indicating their reliability. Thus, it can serve as an efficient tool for determining groundwater U contamination at unmonitored locations in Punjab, thus aiding in groundwater management and attaining SDG 6.

Atmospheric microplastics (MPs) have emerged as ubiquitous environmental pollutants of global concern, with potential risks to ecosystems and human health. This review synthesizes 161 peer‑reviewed articles published between 2021 and 2025, providing a critical assessment of sampling and detection methodologies, physicochemical characteristics, spatiotemporal distribution patterns, human exposure pathways, and health risks. Research indicates that MPs primarily originate from textile fiber release, plastic degradation, and industrial emissions, with fibers and fragments as dominant morphologies and polymer compositions showing distinct regional variations. Distribution patterns differ markedly between indoor and outdoor environments, coastal and inland areas, and dry and wet seasons, regulated by climate, human activities, and land use types. Human exposure occurs mainly via inhalation and dermal contact, with particles < 10 μm readily penetrating respiratory barriers. Notably, this review reveals a systematic discrepancy of 1-2 orders of magnitude between active and passive sampling results, demonstrates that indoor and outdoor concentrations are significantly influenced by ventilation conditions, localized point sources, and environmental parameters, and elucidates the molecular mechanisms of key signaling pathways including oxidative stress and inflammatory responses. Current research still faces limitations in method standardization, detection of small‑sized (nanoscale) particles, and understanding long‑term exposure toxicological mechanisms. Future efforts should focus on advancing cross‑regional, multi‑media collaborative monitoring, developing highly sensitive detection technologies, investigating transport, transformation, and health hazard mechanisms, and establishing health risk‑based exposure limit standards to provide scientific support for targeted pollution prevention and control.

Freshwater fish from mining-influenced rivers can transfer metal(loid)s to consumers, but risk estimates in low resource settings often ignore non-detects, chemical speciation and receptor-specific uncertainty. This study assessed water, sediment and market fish from eight stations along the Akora River, Ghana, and developed a censoring-aware hierarchical Bayesian framework to estimate dietary exposure from Oreochromis niloticus and Clarias anguillaris. Eight metal(loid)s (Hg, Zn, As, Ni, Cr, Cu, Pb and Cd) were analysed by ICP-OES and cold-vapour atomic fluorescence spectroscopy. Posterior fish concentrations were propagated through speciation priors, intake assumptions and dose-response models to estimate non-cancer HI, TCR and BLL for children, WOCBA, adults and high-consumers. Cr and Ni dominated water-column contamination, reaching 55× and 23× WHO guideline values downstream, whereas fish metal concentrations showed little species-specific separation. Median non-cancer HI remained below the screening threshold for all receptor groups, but exceedance probabilities reached approximately 15-17% for children and high-consumers. TCR exceeded 10⁻⁶ in 35-78% of receptor-specific posterior draws, driven mainly by iAs and Cr(VI) assumptions. Median BLL predictions remained below 3.5 µg/dL, although upper-tail exceedance was plausible for children and high-consumers. Sensitivity analysis showed that FIR, BW and speciation/toxicological parameters dominated uncertainty, while additional precision in total-metal concentration had limited value. The results support speciation-focused monitoring, receptor-specific consumption surveys and Ghana-specific freshwater fish consumption guidance.

Mangrove ecosystems play an important role in climate change mitigation through their capacity to store large amounts of blue carbon. Accurate estimation of aboveground biomass (AGB) is therefore essential for monitoring carbon dynamics and supporting sustainable mangrove management. This study evaluated the applicability of Sentinel-2-derived Normalized Difference Vegetation Index (NDVI) for estimating mangrove aboveground biomass and carbon stocks in Pangpang Bay, East Java, Indonesia. Field measurements from 13 sample plots were used to develop an empirical relationship between NDVI and AGB. The resulting regression model (AGB = - 871.15 + 4562.73 × NDVI) showed a significant positive relationship (R2 = 0.649, p < 0.001), indicating that NDVI explained approximately 65% of the observed biomass variability. Application of the model to multitemporal Sentinel-2 imagery (2019, 2022, and 2025) revealed substantial spatial and temporal variation in mangrove biomass and carbon stocks. Biomass and carbon declined markedly between 2019 and 2022, corresponding to a 35.1% reduction in mean NDVI, and showed only limited recovery by 2025. Areas dominated by mature Rhizophora and Bruguiera stands consistently exhibited higher biomass and carbon stocks than Sonneratia-dominated stands. These findings suggest that Sentinel-2 NDVI provides a practical and cost-effective approach for monitoring mangrove biomass dynamics and supporting blue carbon assessment, ecosystem restoration, and monitoring, reporting, and verification (MRV) programs in data-limited coastal environments.

The Tampa Bay estuary is a vital ecological and economic hub, whose productive, shallow-water habitats are highly vulnerable to both chronic anthropogenic stress and acute environmental disturbance events (e.g., extreme weather, human incidents). Historically, the bay's health was monitored primarily through low-frequency, monthly field sampling that has provided a foundational baseline of water quality for the last fifty years. However, discrete sampling is inadequate for capturing the rapid, high-frequency processes that govern the bay's physics and biogeochemistry. Recent perturbations to the Tampa Bay system have exposed this shortcoming and illustrated clearly the need for an autonomous, continuous data acquisition system. This paper introduces the Tampa Bay observing network (TBON), a system designed for high-frequency environmental data acquisition. In addition to detailing its design and operation, case studies are reported to demonstrate its capacity to: (1) supplement traditional low-frequency field sampling, (2) bridge data gaps, and (3) provide continuous monitoring during acute disturbance events when field sampling is impractical. This work is also aimed at informing resource managers and stakeholders about TBON's capabilities and data availability, thereby facilitating its utilization for collaborative research, environmental protection, and effective policy formulation.

Beach management practices are widely implemented in coastal environments, yet their association with litter size structure remains poorly understood. We evaluated macro- and meso-litter across vegetated (unmanaged) and non-vegetated (managed) beach areas along the northwestern Adriatic coast (Italy) through seasonal stratified surveys comprising 448 plot-level sampling events across 112 plots. Meso-litter accounted for approximately 84% of all recorded items. Negative binomial generalized linear mixed models revealed a significant interaction between litter size class and area type (p < 0.001). Macro-litter abundance was 53% lower in non-vegetated areas (p < 0.001), whereas meso-litter abundance did not differ significantly between area types (p = 0.539). Binomial mixed models further indicated a higher predicted proportion of meso-litter within the combined meso- plus macro-litter total in non-vegetated areas (OR = 2.70, p < 0.001), revealing a compositional shift toward smaller debris fractions in managed beach sectors. These findings suggest that beach management is associated with changes in litter size structure and that monitoring approaches based exclusively on macro-litter may not fully capture variation in coastal litter composition. Incorporating meso-litter into monitoring programs could therefore improve assessments of coastal litter dynamics and support more comprehensive management strategies.

Daily total nitrogen (TN) prediction in gate-controlled shallow lakes is hindered by the mismatch between catchment nutrient export and section observations. Here, we introduce response calibration, a new section-scale concept that transforms non-point-source process information from the Soil and Water Assessment Tool (SWAT) into effective predictors by adapting it to transport lag and gate-regulated hydrodynamics. In Honghu Lake, the response-calibrated SWAT-ridge model achieved an RMSE of 0.14 mg/L and an NSE of 0.79 on the 50-day late-autumn/winter independent test set, reducing RMSE by 34.07% relative to conventional monitoring inputs. Raw SWAT outputs added directly as predictors provided no gain, with an RMSE of 0.21 mg/L, showing that their value arose from response calibration rather than from feature addition. The gains were largest during rainfall-affected periods and under low-exchange conditions, when runoff activation and lake retention amplify the source-to-section mismatch. In the 2024 forward evaluation, skill was lower in the highest-concentration quartile, where RMSE reached 0.30 mg/L, and in 2022, a year outside the calibrated regime. This framework provides a practical way to use insufficiently calibrated process-model outputs as section-oriented priors for short-term water quality prediction in hydraulically regulated lakes where inflow water quality is unmonitored.

Metal concentrations during composting reflect changes in dry mass, metal inputs or losses, and the fraction recovered by digestion. Concentrations of Zn, Cu, Fe, Mn, Ni, Cr, Cd, and Pb were measured over 90 days in five poultry litter (PL): vegetable waste blends and analyzed under three assumptions about dry matter loss. Cd in pure-PL compost increased from 0.84 to 3.34 mg kg-1 dry matter. After correction for the loss inferred from Zn and Mn, mean apparent recovery factors were 1.03 for Zn, Cu, Mn, and Ni and 5.11 for Cr, Cd, and Pb (95% bootstrap interval 3.05-8.23). The latter group remained above unity even at 50% assumed loss. Assigning the Fe increase to soil incorporation gave 0.13% mineral addition, accounting for about 4% of the Cr increase and less than 1% of the Pb increase under simplified mixing assumptions. First-order fits gave a mean rate constant of 0.0143 d-1, corresponding to a half-time of 49 days. Increasing digestion recovery could explain these patterns, but unmeasured dry matter loss, metal transfers, and analytical accuracy prevent confirmation of that mechanism or constant metal mass. Day-90 Cd exceeded the EU organic soil improver limit of 2 mg kg-1 dry matter in the two most PL-rich blends. The uncertainty model estimated a 5% exceedance probability at approximately 48% PL. These findings support sampling the finished product, assessing maturity independently, and validating the digestion method.

Nansi Lake is a key regulating lake of China's South-to-North Water Diversion Project. We characterized survey-occasion and spatial variability in water quality and examined associations among physicochemical variables at 62 sites sampled in spring, summer, and autumn 2019 and winter 2021. Water-quality conditions were evaluated using the conventional Nemerow pollution index and the trophic level index; the legacy standard-value-ratio formulation was retained for sensitivity analysis. Total phosphorus (TP) and the permanganate index (CODMn) were elevated in summer and autumn 2019, coinciding with lightly eutrophic conditions, whereas total nitrogen (TN) peaked at 8.46 mg L[-][1] in winter 2021. Linear mixed-effects models showed significant survey-occasion effects on TN, TP, and CODMn (all p < 0.001) and significant survey occasion × lake zone interactions for TN and TP. The conventional and legacy pollution-index formulations were strongly rank-correlated (Spearman's ρ = 0.934), although sample-level pollution grades agreed for 79.4% of observations. Survey-specific Spearman analyses showed that neither temperature-TN nor temperature-TP correlations remained significant after Benjamini-Hochberg false-discovery-rate correction. Because the 2019 surveys and winter 2021 survey were conducted in different years, these contrasts may partly reflect interannual variability and should not be interpreted as pure seasonal effects. Together, these analyses distinguish robust survey-occasion patterns from associations that were not stable across surveys. The results support survey-occasion-specific water-quality monitoring, while hydrological mechanisms and operational measures require validation with synchronous hydrological observations.