Pollutants, Volume 6, Issue 3 (September 2026) – 9 articles

This study examines the long-term associations between ambient air pollutants and the burden of major respiratory and infectious diseases in this geographically sensitive region. A retrospective analysis was conducted using ICD-10-coded hospital records of patients diagnosed with asthma, chronic obstructive pulmonary disease (COPD), bronchitis, and tuberculosis from January 2020 to June 2026. These data were integrated with in situ air quality measurements, including PM₁₀, PM_2.5, and SO₂, as well as satellite-derived Aerosol Optical Depth (AOD) from MODIS. Disease incidence was stratified by year, sex, and age groups (0–85+ years) to assess demographic susceptibility patterns. Respiratory diseases constituted a substantial public health burden over the study period. Asthma showed a marked female predominance (≈29,700 females vs. ≈16,000 males) and a bimodal age distribution with peaks in early childhood (0–5 years) and mid-adulthood (35–50 years). COPD was predominantly observed in males (≈8300 males vs. ≈5500 females), with a higher median age range (≈67–70 years). Bronchitis exhibited a similar bimodal pattern, disproportionately affecting both pediatric and elderly populations, while overall case numbers declined over time. Tuberculosis incidence was approximately threefold higher in males than females, with notable age-related divergence, affecting younger females (≈30–32 years) and middle-aged males (≈42–45 years). The findings suggest a spatial–temporal correspondence between elevated pollutant concentrations and respiratory disease prevalence in the Iğdır Basin. The observed sex- and age-specific disparities underscore the potential value of region-specific environmental health strategies, strengthened air quality management, and continuous epidemiological surveillance in enclosed basin environments. Full article

Methanol is highly soluble and with spreads quickly in natural water bodies, which could bring about serious environmental risks if leaked. In the present work, the transport and diffusion behavior of methanol in an open-channel flume under controlled hydraulic conditions is investigated experimentally. A closed-loop experimental system was designed to mimic the pipeline leakage scenarios and image-based reconstruction methods were applied to quantify the spatiotemporal evolution of the methanol concentration fields. Systematic analysis was performed on the effects of flow velocity, water depth, leakage rate and leakage location. The results indicate that flow velocity is the dominant factor controlling the downstream advective transport, with increasing velocity significantly reducing the downstream extent of high-concentration zones. Water depth affects vertical mixing and dilution capacity, with deeper flows maintaining more persistent plume structures. Higher leak rates result in higher local concentrations and larger near-field contaminated regions. The position of the leakage is also very important for the plume morphology: the boundary effects lead to a limited and asymmetric dispersion when the leakage is close to the boundary, while the dispersion is more symmetric when the leakage is in the middle of the domain. The study highlights the combined roles of advection, turbulent mixing and boundary confinement in governing methanol plume evolution. The results provide experimental evidence for the understanding of soluble pollutant transport mechanisms in open-channel flows under simplified hydraulic conditions. Full article

Potentially toxic element (PTE) contamination of food systems has emerged as an important environmental and public health concern in many developing countries, including Uganda, owing to rapid urbanization, industrialization, mining activities, wastewater reuse, informal waste disposal, and expanding urban agriculture. This review synthesizes evidence from peer-reviewed and selected grey literature on the occurrence of cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), and arsenic (As) in cereals, vegetables, tubers, livestock products, fish, fruits, and processed foods consumed in Uganda. A structured literature synthesis and screening-level dietary risk assessment using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), carcinogenic risk (CR), and total carcinogenic risk (TCR) were conducted to identify contamination hotspots, priority exposure pathways, and potential public health implications. The available evidence revealed substantial spatial variability, with contamination consistently concentrated in mining-influenced agricultural areas, wastewater-irrigated farms, municipal dumpsites, industrial corridors, and urban food markets. Vegetables, cereals, livestock products, fish, and street-vended foods exhibited the greatest contamination burdens, while Pb and Cd were the PTEs most frequently reported exceeding WHO/FAO, Codex Alimentarius, and Ugandan food safety limits. Screening-level risk estimates indicated that Pb, Cd, and Cr contributed most to cumulative dietary exposure, with children consistently exhibiting higher EDI, THQ, HI, and TCR values than adults because of greater food intake relative to body weight. Although cumulative HI and TCR values exceeded recommended screening thresholds in several hotspot regions, these estimates should be interpreted as conservative screening-level indicators derived from heterogeneous published datasets rather than nationally representative measures of dietary exposure. Overall, the evidence indicates that PTE contamination in Ugandan food systems is predominantly hotspot-driven and highlights the need for targeted surveillance, standardized monitoring and reporting, improved pollution control, and strengthened food safety management to reduce chronic dietary exposure and protect public health. Full article

Chromium contamination in aquatic systems represents a significant environmental concern due to its toxicity and complex geochemical behaviour. This study analyzes the spatial distribution of total chromium (Cr) in sediments from streams and surface waters of the Iron Quadrangle (IQ), one of the world’s most important mining provinces, with the aim of establishing regional reference values and identifying anomalous concentrations. A total of 487 samples were collected, corresponding to an average sampling density of one sample per 14.37 km². Statistical approaches, including the Upper Inner Fence (UIF) method, were applied to distinguish background levels, elevated concentrations, and anomalies, while contamination factor and enrichment factor indices were used to assess contamination and enrichment patterns. The results indicate a wide range of Cr concentrations, with sediments reaching up to 2581 mg·kg⁻¹ and surface waters up to 384.7 μg·L⁻¹. Although most samples reflect natural background conditions, significant anomalies were identified, particularly in areas associated with mafic–ultramafic lithologies and mining activities. Approximately 73.3% and 42.3% of sediment samples exceeded TEL and PEL thresholds, respectively, while 35.3% of surface water samples surpassed drinking water limits. The results highlight the need for continuous environmental monitoring and reinforce the importance of integrating geochemical mapping with risk assessment approaches to better understand contamination dynamics in complex mining regions. Full article

Hydrodynamic cavitation has attracted increasing attention in water and wastewater treatment because it can generate localized shear, pressure fluctuations, interfacial renewal, and reactive species in relatively simple continuous-flow devices. This review critically examines its main application domains, including microbial disinfection, cyanobacterial bloom control, organic micropollutant degradation, real wastewater treatment, sludge pretreatment for energy recovery, and hybrid process configurations. Rather than treating hydrodynamic cavitation as a single treatment mode, the discussion compares applications in relation to reactor design, matrix characteristics, treatment target, operating conditions, and assigned process function. The analysis shows that performance depends strongly on the interaction among device geometry, treated matrix, process configuration, and evaluation metrics. The same nominal process may therefore act as direct treatment, pretreatment, mass-transfer intensifier, oxidant-activation module, or support to downstream biological and polishing steps. The most consolidated evidence concerns microbial disinfection, sludge pretreatment, and several classes of organic contaminants, whereas PFAS treatment, field-scale validation, and system-level assessment remain less mature. Overall, hydrodynamic cavitation is best interpreted as a process-intensification platform rather than as a universally applicable stand-alone solution. Further progress will require more transparent assessment criteria, more comparable metrics, stronger validation in real matrices, more controllable reactors, and more rigorous energy, techno-economic, and scale-up evaluation. Full article

Environmental impacts of wastewater from textile and dyestuff industries are of growing concern due to limited freshwater availability and inadequate treatment facilities. Carbon nanotubes (CNTs) offer excellent adsorption potential because of their outstanding mechanical and chemical properties, however; their application in textile effluent treatment has not been widely studied. Moreover, laboratory-based studies are often costly and limited to a few variables, making it challenging to reveal the underlying relationships among several physicochemical parameters and CNT treatments. Multivariate statistical analysis (MVSA) offers an effective approach to overcome this challenge. To the best of our knowledge, no studies have integrated laboratory analysis of nanotube-based textile effluent treatment with an MVSA approach. This study aims to evaluate the physicochemical characterization of textile effluent, treat effluent with CNT, and explore the relationship between physicochemical parameters and CNT by integrating laboratory experiments with MVSA. For this purpose, single-walled CNT (SWCNT) and multi-walled CNT (MWCNT) were applied in batch mode adsorption experiments using various dosages and adsorption times. Scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR), along with physicochemical analyses, were conducted to characterize the effluent and adsorption processes. The FTIR spectrum indicated that the absorption peaks of C=C, C=O, and the acidic f -OH group on CNTs enhance wettability and hydrophilic character, thereby increasing adsorption capacity. Experimental results demonstrated significant reductions in electrical conductivity (EC), total dissolved solids (TDS), turbidity, total organic carbon (TOC), and chemical oxygen demand (COD). CNT dosages of 1 to 5 g/100 mL and adsorption times of 2 to 5 h achieved removal efficiencies ranging from approximately 20% to 90% for SWCNT and MWCNT. MVSA indicated that MWCNT was more strongly associated with ionic and physical parameters (turbidity, TDS, EC, and pH), whereas SWCNT was more strongly related to organic load indicators, particularly COD and TOC. Overall, this study highlights the potential of CNT coupled with the MVSA technique as an effective and sustainable approach for textile wastewater treatment and offers valuable insights for researchers working in this field. Full article

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants with growing evidence of systemic health effects, but their potential influence on gastrointestinal function remains poorly understood. This study evaluated associations between serum PFAS mixtures and bowel health indicators, including self-reported constipation and bowel movement frequency, among 116 U.S. adults aged ≥20 years from the 2009–2010 National Health and Nutrition Examination Survey. Six PFASs were examined: PFOS, PFOA, PFHS, PFNA, PFDE, and PFUA. Constipation was assessed using the NHANES Bowel Health Questionnaire item coded from 1 = Always to 5 = Never, so that higher values represented less frequent self-reported constipation, and bowel movement frequency was recorded as movements per week. Bayesian kernel machine regression (BKMR) estimated joint and nonlinear mixture effects, and survey-weighted regression models examined individual PFAS, each adjusted for age, sex, body mass index, education, and income. Higher combined PFAS exposure was associated with higher constipation response scores across the mid-range of exposure, indicating less frequent self-reported constipation, with PFOA identified as the primary contributor through a nonlinear, inverse U-shaped exposure–response pattern. In survey-weighted models, PFOA and PFUA were associated with less frequent self-reported constipation, whereas PFNA was associated with more frequent constipation. Associations with bowel movement frequency were weak and inconsistent; only PFOS reached significance in regression, and this association would not survive correction for multiple comparisons, so these data provide little evidence of a robust association between PFAS and bowel movement frequency. Overall, higher PFAS exposure was associated with less frequent self-reported constipation, particularly for PFOA, whereas evidence for an association with bowel movement frequency was limited. Full article

Air pollution negatively impacts human health and environmental sustainability, particularly in areas with high industrial activity. This study comparatively evaluated deep learning-based models for estimating PM₁₀ and SO₂ pollutants in Dilovası and Ereğli (Turkey), industrial areas with high pollutant loads. The study utilized Recurrent Neural Networks (RNNs), Long Short-Term Memory (LSTM), Gated Recurrent Units (GRUs), an RNN–GRU stacked hybrid model, an attention-based hybrid model, and the proposed GRU–LSTM dual-path hybrid model. The proposed method consists of four main stages: data conversion into a time-series format, data preprocessing and feature generation, model architecture development, and model training and performance evaluation. The dataset consisted of 365 daily PM₁₀ and SO₂ observations obtained from the Air Monitoring Center for the Dilovası and Ereğli monitoring stations. Model performance was evaluated using the coefficient of determination (R²), training time, root mean squared error (RMSE), mean squared error (MSE), and mean absolute error (MAE) metrics. The findings showed that the hybrid models provided higher accuracy compared to the single-track models. Specifically, the proposed GRU–LSTM dual-path hybrid model produced the highest R² and lowest error values for both pollutant parameters in both the Dilovası and Ereğli regions. In Dilovası, this model achieved R² = 0.97 for SO₂ and R² = 0.96 for PM₁₀; in Ereğli, it reached R² = 0.92 for SO₂ and R² = 0.98 for PM₁₀. Thus, it has been shown that the GRU–LSTM dual-path hybrid model, which models short-term and long-term temporal dependencies in parallel, is an effective and reliable method for air pollutant forecasting in industrial areas. These findings demonstrate the potential of the proposed model to support air quality monitoring, early warning systems, and environmental decision-making in industrial regions. Full article

Microplastics are ubiquitous environmental particles with complex physical and chemical properties that enable them to interact with other contaminants. Recent evidence suggests that microplastics act as carriers for various chemical pollutants, altering their transport, deposition, and deposition dose. This conceptual review synthesizes current knowledge of radon progeny behavior and microplastic properties and suggests potential mechanisms for their interaction, although direct experimental validation of radon progeny specifically is currently lacking. It discusses attachment kinetics, transport pathways in air and water, and microplastic-mediated shifts in human lung deposition patterns and ecological exposure. Theoretical dosimetry reasoning suggests that, if attachment occurs, small respirable microplastics (1–10 μm) could increase inhalation doses by prolonging the airborne residence time of progeny indoors, whereas macro- and coarse microplastics would primarily affect localized environmental hotspots. These possibilities remain to be tested experimentally. Integrated experimental and modelling approaches, including radon chamber studies, aerosol and aquatic transport experiments, respiratory tract modelling, and ecological bioassays, are proposed to quantify these processes and inform risk assessment. Knowledge gaps remain in attachment efficiency, retention, co-contaminant interactions, and long-term exposure scenarios. Addressing these gaps is critical for refining human and ecological risk assessments and guiding regulatory frameworks in radon-microplastic-impacted environments. Full article