Urban noise pollution is a critical environmental stressor in cities, yet its drivers in dense, historic cores are poorly quantified. This study investigates the pedestrian-level acoustic environment in Isfahan, Iran, a historic city grappling with severe traffic congestion, to guide targeted policy interventions. We measured equivalent sound pressure levels (L-Aeq), exclusively representing the overall exposure, at 120 roadside locations during three diurnal periods, revealing a significant increase from morning (58.9 +/- 2.49 dB(A)) to afternoon (71.6 +/- 3.34 dB(A)). These measurements were synthesized into a composite Noise Index (NI) using Principal Component Analysis, where the first component explained 78.5% of the variance. A Generalized Linear Model (GLM) quantified the influence of fourteen urban variables on the NI. The model explained 86.3% of the variance (RMSE = 0.565), identifying Vehicle Flow Rate (VFR) and Commercial Land Use (CLU) as the dominant statistical predictors (drivers). A sensitivity analysis confirmed their paramount influence, with VFR and CLU exhibiting the largest effect sizes (Delta = 2.943 and 2.136, respectively). In contrast, small, discontinuous green patches, road width, and building height were statistically insignificant (p > 0.05). Beyond quantifying noise levels, the results provide a contextualized assessment of how mobility- and activity-related factors shape exposure in compact historic settings. These findings underscore a strong statistical association, demonstrating that in compact historic settings, pedestrian-level noise is most strongly linked to mobility systems and land-use function rather than to the measured elements of physical morphology.

Ambient aerosol pollution during pregnancy has been linked to adverse neonatal outcomes, but the relative importance of exposure timing versus intensity remains uncertain. This study investigated associations between maternal ambient aerosol exposure and neonatal cord blood hepatic enzyme activities among 92 newborns in Ahvaz, Iran, a city with severe particulate pollution. MODIS AOD data were used to estimate exposure across all gestational months. Cord blood biomarkers measured included ALT (21.1 ± 9.7 µ/l), AST (29.4 ± 11.3 µ/l), ALP (473.2 ± 105.8 µ/l), and GGT (147.9 ± 103.8 µ/l). Principal Component Analysis and Generalized Linear Models, adjusted for maternal age and infant sex, showed that cumulative exposure (PC1, 48.23% variance) and peak aerosol events (PC2, 13.58% variance) significantly increased several biomarkers (ALT: β = 0.631, p = 0.004; GGT: β = 6.996, p < 0.001). AST was marginally associated with cumulative exposure and significantly related to maternal age. Infant sex influenced GGT levels, while trimester-specific exposure showed limited effects. Overall, cumulative and peak aerosol exposures were found as the primary exposure patterns associated with altered neonatal cord blood hepatic enzyme activities, underscoring the need to reduce sustained and high-intensity pollution to protect fetal health.

Urban public transport is a critical source of environmental acoustic pollution, yet the specific drivers of its disruptive and highly transient pollution intensity at bus stops remain poorly quantified. This study investigated the determinants of short-term acoustic pollution fluctuation, defined as the difference between the L10 (peak) and L50 (median) sound levels (ΔNoise), at 100 bus stations in Isfahan. Using a stratified sampling design, we collected continuous acoustic measurements alongside contextual data on traffic and passenger activity. A generalized additive model (R2 = 0.837) was employed to analyze the non-linear effects of predictors on ΔNoise as an indicator of fluctuating pollution intensity. The results revealed a highly impulsive acoustic pollution environment, with a mean ΔNoise of 6.30 dB. Motorcycle count was the dominant predictor, exhibiting a strong, linear positive relationship (edf ≈ 1.00, F = 200.87, p < 0.001). Vehicle speed showed a significant non-linear effect (edf = 3.31, p < 0.001), with ΔNoise peaking at intermediate speeds ( 35 km/h). Scenario analysis demonstrated that a 60

Urbanization transforms land use and environmental processes, often concentrating potentially toxic elements in surface dust. However, the influence of urban morphology (beyond simple density measures) on spatial patterns of lead (Pb) accumulation in road dust remains insufficiently understood, particularly in arid-region landscapes. This study evaluated how urban structure and landscape configuration influence Pb enrichment in road dust across 70 urban settlements in Isfahan Province, central Iran. Road dust samples from 100 locations (70 urban, 30 non-urban) were analyzed for Pb concentration. A spatial lag model assessed relationships between Pb excess (urban minus background) and 12 predictors representing built-up intensity, road networks, fragmentation, and soil properties. Urban Pb concentrations (127.77 ± 31.09 mg kg−1) exceeded non-urban levels (29.93 ± 6.69 mg kg−1) by more than fourfold. The spatial lag model explained 93.4

Traffic-related noise pollution in densely populated cities is one of the most significant environmental challenges. Although urban green spaces are widely recognized as natural buffers for mitigating high noise levels, the relative contributions of the factors involved have rarely been disentangled. This study aimed to separate and quantify these contributions across 50 small urban green spaces in central Isfahan. To this end, a two-stage sequential generalized linear modeling approach was employed. In the first-stage model, representing noise propagation, road density, traffic intensity, and distance to the road were used as predictors. In the second-stage model, representing noise reduction, the residuals of the first model were modeled using two variables: park greenness, measured by NDVI, and park area. The first model explained 71% of the variance in noise levels (R² = 0.713), with the relative contributions of road density, traffic intensity, and distance to the road being 66%, 24%, and 10%, respectively (all p < 0.01). The second model explained 50% of the variance in the residuals (R² = 0.502), with park greenness making a substantially greater contribution, 68% (p = 0.004), than park area, 32% (p = 0.016). Moreover, the second model improved the root mean square error by 37% compared with the first model. These findings indicate that vegetation quality, as reflected in greenness, is more effective in reducing noise levels than simply increasing park size. From an applied perspective, in cities with limited resources, enhancing vegetation density along park edges should be prioritized over the horizontal expansion of parks in urban soundscape planning.

Background: Polychlorinated biphenyls (PCBs) are persistent organic pollutants of significant concern due to their adverse health effects and widespread presence in indoor environments. Understanding the distribution and sources of PCB contamination in indoor settings is critical for effective risk management and mitigation strategies. Methods: Dust samples were collected from 28 locations within public buildings in Isfahan. The concentration of PCBs was determined using an Agilent 7890A gas chromatograph-mass spectrometer. Additionally, the carcinogenic risk (CR) associated with PCB exposure via ingestion, inhalation, and dermal contact was assessed for both children and adults. PCBs with six chlorine atoms in their structure were the dominant group, with a mean concentration of 74.42±22.10 ng/g. Results: The CR values were categorized as low for both age groups via ingestion and dermal pathways, ranging between 4.04E-05 and 2.27E-05. Furthermore, all sampling locations were classified as low risk in terms of total CR effects. Conclusion: Inhalation risks from PCB exposure were relatively low; however, concerns persist regarding PCBs acting as vectors for other contaminants, thus amplifying health risks through dermal contact and ingestion. Effective management strategies are essential to mitigate PCB exposures and protect public health in indoor environments.

Dust sources are expanding unprecedentedly across the arid parts of Iran. To quantify this trend in the Kaftar Catchment in SW Iran (5,600 km(2)), the MODIS AOD product "Optical_Depth_047 '', accessible through Google Earth Engine was utilized, as one of the moderate-resolution (1 km) aerosol data sources spanning from 2002 to 2023. The layers were preprocessed and averaged to derive annual mean data (AM-AOD), and its accuracy was verified using reference dust data collected from 24 stations in 2022 (correlation coefficient = 0.565; p-value < 0.01). The Mann-Kendall trend test confirmed a statistically significant upward trend in AOD values. A positive Sen's slope predominated for the majority of the AM-AOD pixels. The Generalized Additive Model (mean R-2 = 0.753) successfully predicted AM-AOD values at each pixel for the year 2035. According to the Landsat 8-derived LULC map of the region (Kappa = 83.56), the wetland area is projected to experience the highest increase in AM-AOD in 2035, reaching 0.43 +/- 0.06, while rangelands are expected to observe the lowest increment at 0.17 +/- 0.07. Our study underscores the urgency of rehabilitating the Kaftar Wetland, promoting low-water crops, and improving ecosystem resilience in rangelands. (c) 2024 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Background: Microplastic (MP) pollution significantly threatens aquatic ecosystems in Iran because of increasing human activities affecting inland surface freshwater resources. Methods: Our study focused on the Choghakhor International Wetland, quantifying the presence of MPs on the wetland surface sediment, revealing an average of 87.5 +/- 11.5 pieces per kilogram of sediment throughout the wetland. We employed the Generalized Additive Model to identify local factors influencing the accumulation of MPs, considering various uncorrelated variables, including electrical conductivity (EC; average = 570.0 +/- 14.0 dS/m), pH (average = 6.98 +/- 0.07), organic matter (OM; average = 3.51 +/- 0.32 %), the Soil Texture Index (STI), Landsat-derived water depth (DEP; R-2 = 0.659), and substrate slope (SLO). Results: The results of the GAM model (R-2 = 0.750; Deviance explained = 79.1%) revealed that sediments with finer particles enriched with elevated OC and EC content on flat substrates within the wetland are more susceptible to the accumulation of MPs. Conclusion: These findings underscore the substantial role of sediment attributes, and to a lesser extent, substrate physical characteristics in shaping the dynamics of MP pollution in the Choghakor Wetland.

The Kaftar Wetland, covering approximately 5,600 km², is located about 180 km north of Fars Province and has completely dried up. The present study evaluated the concentrations of selected heavy metals – cadmium, arsenic, cobalt, lead, chromium, nickel, zinc, and manganese – in sediments of the dried Kaftar Wetland, where wetland desiccation and upstream agricultural activities have contributed to the formation of critical dust and pollution hotspots. A systematic sampling method was used to determine sediment sampling locations. The wetland area was divided into 24 blocks, and one point in each block was randomly selected for sampling. Surface sediment samples were collected in spring and autumn 1400 (Iranian calendar) from a depth of 0 - 10 cm. Samples were transported to the laboratory in zip-lock bags and, after drying, digestion, and preparation, metal concentrations were measured using an Agilent MP-AES (Model 4100). Quality control was performed using control samples and reference standards to ensure analytical accuracy. Among the measured metals, cadmium showed the highest concentration (0.84 mg/kg), placing it in the strong to very strong contamination range at several stations, whereas other elements generally remained within lower contamination ranges across both seasons. The elevated cadmium levels were attributed primarily to upstream agricultural activities.

The urban areas of Iran, particularly Isfahan City, are significantly affected by air pollution. Isfahan’s core area contains multiple small urban parks where surface dust provides valuable insights into the presence of Potentially Toxic Elements (PTEs). Dust samples collected from the corners of hard concrete pavements at the central points of 73 well-distributed parks (mean area: 8.38 ± 0.11 ha) were found to be contaminated with Ni (34.17 ± 7.58), Pb (30.22 ± 3.34), Zn (125.73 ± 34.47), and Cd (1.15 ± 0.40). Principal Component Analysis (PCA) was employed on a large number of spatial and physicochemical variables to reduce their dimensionality, resulting in six primary components related to park vegetation, annual mean PM2.5 concentration, the organic carbon content of the samples, and the percentage area of nearby residential zones. The use of the Generalized Additive Model indicated that four PTEs—Ni, Pb, Cr, and Cd (0.39 < R2 < 0.63)—are less likely to accumulate in park surface dust in areas with dense, leafy vegetation during summer. A robust positive correlation was also modeled between PM2.5 levels and the concentrations of Pb and Ni. The study concludes that a combination of factors influences the concentration of PTEs in the dust of Isfahan’s parks, with each factor contributing differently to the levels of various PTEs. • Surface dust in small parks within Isfahan's core area was contaminated with Ni, Pb, Zn, and Cd • Vegetation played a crucial role in the deposition and retention of PTE-bound dust. • Areas with elevated PM2.5 concentrations exhibited higher levels of PTEs in their dust. • Parks surrounded by a higher percentage of residential areas experienced elevated levels of Pb and Zn.

The Middle Eastern countries of Iran and Iraq are critical regions for warming analysis due to their vulnerability to extreme heat impacts. This study examines surface heat zone dynamics across Iran and Iraq, focusing on MODIS land surface temperature (LST). Both countries exhibited a sharp trend of expanding extreme heat areas from 2002 to 2023, with 47.03

Road dust is a significant environmental concern in urban areas, acting as a reservoir for various potentially toxic elements (PTEs). This study investigates the spread and contamination of PTEs - As, Cd, Ni, Pb, Co, Cr, Cu, and V - in 50 road dust samples across an urban-rural (downtown, midtown, and rural areas) gradient in Al-Qasim City, Iraq. Fifty dust samples were collected, representing concentrations above world means for As (43.66 +/- 5.98 mg/kg), Ni (113.18 +/- 33.70 mg/kg), Cr (195.30 +/- 60.52 mg/kg), and Co (14.73 +/- 4.38 mg/kg). The differences between PTE concentrations were not significant across the urban-rural gradient. As showed a moderate level of geochemical contamination and, together with Cr and Ni, represented a significant enrichment. The pollution load index (PLI) was also extremely high (PLI >3) for all PTEs. Canonical Correspondence Analysis (CCA) indicated that Cr, Ni, and Co are closely associated with urban-related factors, including distance from the city center and road density. Cu, V, Pb, and Co also showed positive correlations with a Landsat-derived Normalized Difference Vegetation Index (NDVI), emphasizing the role of vegetation in PTE distribution. The findings revealed the complexity of PTE distribution due to the influence of various environmental factors, highlighting the urgent need for comprehensive environmental management and remediation strategies in the region.

Roadside environments are critical interfaces where transportation systems intersect with urban ecosystems, often acting as hotspots for the accumulation of potentially toxic elements (PTEs). In arid and semi-arid regions with aged vehicle fleets and fuel quality concerns, the persistence and dispersion of PTEs pose heightened environmental and public health risks. This study aimed to investigate the spatial patterns, potential sources, and environmental drivers of PTE concentrations (Pb, Cd, Zn, Cu, Ni, Cr) in roadside soils west of Isfahan City, Iran. Surface (0-2 cm) and background (30 cm) soils were collected from 209 stations, and analyzed using standard protocols with detection limits ranging from 0.1 to 1.0 ppm. Principal Component Analysis (PCA) identified two dominant components: PC1 (Zn, Cu, Cr) related to mechanical abrasion, and PC2 (Pb, Cd, Ni) linked to combustion sources. Least Absolute Shrinkage and Selection Operator (LASSO) regression and sensitivity analysis revealed that PC1 was primarily predicted by road slope and curvature, while PC2 was best explained by traffic volume and diesel vehicle proportion (R2 = 0.561 and 0.686, respectively). The results highlight the dual role of structural and operational road factors in shaping PTE distribution in dryland cities, with implications for land use planning and pollution mitigation in rapidly urbanizing regions.

Background: Heavy metals (HMs) are toxic pollutants whose concentrations in confined spaces might cause severe health impacts. This study aimed to determine the concentration and health risk of As, Cd, Co, Pb, Mn, Ni, and V in indoor household dust in Isfahan during 2022-2023. Methods: Ninety dust samples were collected from 30 sampling homes. After preparation and acid digestion of the samples in the laboratory, the concentrations of the elements were determined using the ICP-OES method and analyzed statistically. Results: Except for Pb, the HMs’ mean concentrations were significantly lower than the permissible limit (P < 0.050). The maximum daily exposure through ingestion, inhalation, and dermal contact for children and adults were 66.1 and 79.1 mg/kg/d, respectively, with Pb as the relevant element in both groups. Furthermore, the maximum lifetime daily exposure doses of 8-10 × 26.1 mg/kg/d belonged to Pb. The maximum non-carcinogenic and carcinogenic risk values through direct ingestion, inhalation, and dermal contact were 4.83 × 1-10 and 1.40 × 8-10 for children and 5.23 × 2-10 and 7.91 × 9-10 for adults, which were associated with Pb in both groups. Conclusion: The results showed that the HMs content in indoor household dust in Isfahan followed a decreasing trend of Pb > Mn > Ni > V > As > Co > Cd. Moreover, direct ingestion followed by dermal contact and inhalation were the most important exposure pathways to the HMs-contaminated dust for both children and adults.

Pregnant women are highly vulnerable to environmental stressors such as ambient particulate matter (PM). Particularly during their 3rd trimester, their bodies undergo significant oxidative stresses. To further consolidate this dialogue into practice, the current study evaluated healthy pregnant women (n = 150 housewives; 18-40 years old; gestation age >36 weeks) from the highly polluted city of Yazd, Iran, from September to November 2021. The aerosol optical depth (AOD) data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) were employed as influencing variables and validated using field-collected PM10 data (r = 0.62, p-value <0.01). The links between blood platelet count, enzymes (SGOT, SGPT, LDH, bilirubin), metabolic products (urea and acid uric) and different combinations of AOD data were assessed using the Generalized Additive Model. The results showed a high temporal variability in AOD (0.94 +/- 0.51) but a spatially stable distribution pattern. The mean AOD during the 3rd trimester, followed by that of the three-month peak, were identified as the most significant non-linear predictors, while the mean AOD during the 1st trimester and throughout the entire pregnancy showed no significant associations with any of the biomarkers. Considering the associations found between AOD variables and maternal oxidative stresses, urgent planning is required to improve the urban air quality for sensitive subpopulations.

Background: Cities negatively affect the environment. Urban pollution levels have risen considerably, affecting sensitive groups such as pregnant women. Methods: This study aimed to investigate the relationship between particulate matter and kidney biomarkers of pregnant women in Yazd from September to November 2023. Urea, uric acid, and creatinine levels were measured in 30 pregnant women (third trimester). The concentration of PM2.5 was estimated using the land use regression (LUR) model and 5 independent variables of road networks, distance from the city center, building density, elevation, and slope. For each mother, the mean concentration of the modeled PM2.5 was measured in multiple buffer rings drawn around her residential location. Generalized additive model (GAM) was employed to establish a relationship between PM2.5 concentrations with physiological indicators. Results: Average urea, uric acid, and creatinine were 18.06 ± 5.74, 3.65 ± 1.11, and 0.79 ± 0.12 mg/dL, respectively. The LUR model identified road networks and distance from the city center as critical factors contributing to increased particulate matter concentration. The GAM R2 was 0.79, 0.31, and 0.28 for urea, uric acid, and creatinine, respectively. The mean PM2.5 within a radius of 2000 m was identified as the most significant independent variable and showed an increasing impact on the renal parameters. Conclusion: According to the results, reducing pollutant levels and preventing the creation of pollution hotspots via lowering road density are vital urban planning strategies to protect vulnerable groups, especially pregnant women.

The coagulation and flocculation method stands out as a widely utilized approach in industrial wastewater treatment. This study explores the application of a new sedimentation concept, focusing on one-step removal, and evaluates the effectiveness of polyaluminum chloride (PAC) and anionic polyacrylamide (PAM) in reducing turbidity in simulated hot-rolled steel factory effluent. The investigation considers various independent variables such as pH, stirring time, temperature, and concentrations of oil and suspended solids. The response surface method (RSM) is employed for a more precise examination of these parameters. Results indicate that increasing PAC dosage to 5 mg/L enhances turbidity removal efficiency, meeting the water turbidity standard of less than 20 NTU for the rolling process. Conversely, the highest efficiency with polyacrylamide occurs at a lower concentration (0.1 mg/L), with efficiency decreasing as PAM amounts rise, hindering coagulation and flocculation processes. Despite polyacrylamide’s higher consumption efficiency, the study suggests that PAC exhibits superior wastewater turbidity removal at optimal concentrations. Overall, this research introduces a novel one-step treatment method for rolling mill effluent, streamlining the process, reducing energy consumption, and lowering treatment costs as compared to traditional methods.

Noise pollution poses a significant environmental challenge in Iranian urban areas, particularly within Small Urban Green Parks (SUGPs). This study investigates the extent of noise pollution in SUGPs and identifies key contributors to elevated noise levels. A total of 94 SUGPs, with a mean area of 1.86 +/- 0.99 hectares, were selected in Isfahan City, Central Iran, and subjected to 30-m Equivalent Sound Level (Lq30) measurements at their central locations. Explanatory variables were classified into two categories based on road density, traffic volume, proximity to roads, park vegetation, and physical characteristics. The relationship between noise levels and each explanatory variable was observed to be non-linear and polynomial (R-2 < 0.334) in certain instances. Our modeling results using the Multi-Layer Perceptron (MLP)-Artificial Neural Network (ANN) model (R-2 = 0.936) indicate that average noise levels in these parks surpass international guidelines, averaging 65.97 +/- 17.76 dB. Traffic volume and proximity to limited access roads were identified as primary factors influencing noise levels in SUGPs. It was observed that the design and layout of small urban parks may not effectively mitigate surrounding traffic noise, even with sufficient green barriers to absorb or block sound. Consequently, future efforts should prioritize strategic site selection for SUGPs to minimize exposure to major noise sources.

Microplastics (MPs) are an emerging pollutant whose ability to adsorb potentially toxic elements (PTEs) poses a serious threat to aquatic ecosystems, including rivers. In highly developed basins, the abundance of MPs in river sediment is expected to be high, elevating the sedimentary accumulation of PTEs. This hypothesis was tested in the Zayandeh-Rood River, Central Iran, with 21 sediment sampling stations distributed along the entire river stretch. Results of sediment analysis showed significant variations in the abundance and size of MPs, with concentrations ranked as Ba (270.71 mg/kg) > Li (21.29 mg/kg) > Cs (2.50 mg/kg) > Be (1.44 mg/kg) > Sn (1.17 mg/kg) > Mo (1.06 mg/kg) > Ag (0.76 mg/kg), along with sediment physicochemical attributes such as EC, TOC, pH and grain size. MPs were identified in all sediment samples with a mean of 588 items/kg dry weight. Except for Ag, all other PTEs were classified as uncontaminated but exhibited increased enrichment downstream. According to the results of the generalized additive model (maximum R-sq of 0.766), the sedimentary concentration of the majority of PTEs is nonlinearly and positively associated with smaller and more abundant MPs. This study acknowledges that MPs might influence sediment porosity, permeability and structure, thereby directly affecting the settling dynamics of other particles, especially PTEs.