Search Results (2,118)

Urbanization affects bird communities by reducing habitat and fragmenting ecosystems. Urban parks can help counteract these effects. However, anthropogenic noise can further alter bird composition. We examined the distribution and abundance of bird species in nine urban parks in Mexico City. We used a ten minute fixed-radius (25 m) point-counting technique to count birds along their annual cycle, with ten minutes allocated for bird counts. The quality of green areas was analyzed in terms of vegetation (Normalized Difference Vegetation Index), park size, and mean noise level dB(A) (based on MIN and MAX values), and species were grouped into trophic guilds. A total of 108 bird species were recorded, 5 of which are under special protection; we grouped all species into 14 trophic guilds, showing different responses to environmental gradients. Redundancy analysis (RDA) explained 89.98% of the variance, with noise and park size being the most influential variables. Granivores and omnivores were more tolerant to noise, while insectivores and frugivores preferred quieter areas with more vegetation. A positive association was observed between the presence of winter resident species and the park size. On the other hand, mean noise level dB(A) was negatively related to permanent resident species, winter resident species, and those with protected status. Conservation efforts should focus on maintaining ample green spaces and reducing noise pollution, as recorded high mean noise levels (>53 dB(A)) exceed the recommended thresholds for avifauna conservation. Full article

A necessary evaluation of freshwater ecosystem pollution levels and radiation risks remains crucial for maintaining environmental health, especially within economically developing areas. This study presents a comprehensive evaluation of the mineralogical, geochemical, and radiological characteristics of sediments in Nasser Lake, Egypt, to determine potential ecological and health risks. Forty sediment samples were collected from multiple locations, including both surface and bottom sediments, for analysis of textural attributes, mineral composition, potentially toxic elements, and natural radionuclides (²³⁸U, ²³²Th, and ⁴⁰K). Results revealed sand-dominated sediments with low organic matter content. The heavy mineral assemblages derived from Nile River inputs, wind-deposited materials, and eroded igneous and metamorphic rocks. Geochemical analysis showed that arsenic, cadmium, chromium, and lead concentrations exceeded upper continental crust background values, with enrichment factors and geo-accumulation indices indicating significant anthropogenic contributions. The pollution indices revealed heavy contamination levels and extreme ecological risks, which were primarily driven by arsenic and cadmium concentrations. Radiological assessments detected activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K below the world average, with hazard indices indicating minimal radiological risk except where localized hotspots were present. The study emphasizes the need for targeted monitoring and sustainable management practices to mitigate pollution and preserve the crucial freshwater environment of Nasser Lake. Full article

Microplastic (MP) pollution in aquatic ecosystems poses significant ecological and public health risks. A comprehensive understanding of estuarine MP pollution, influenced by multiple anthropogenic and environmental factors, remains elusive in current research. This study investigated the spatial distribution patterns and dominant factors influencing MP abundance (MPA) and physicochemical diversity in the river water and sediments of the Pearl River Estuary (PRE), while also assessing the associated ecological risks. The dominant MP categories in river water and sediments were fibers, clear in color, <1 mm in length, and composed of polyethylene terephthalate and polypropylene. Whereas inland regions showed higher MPA, nearshore regions exhibited marginally greater physicochemical diversity. Multivariate statistical analysis identified population density as the primary driver of both MPA in river water and MP physicochemical diversity in sediments. MP physicochemical diversity in river water was predominantly governed by the synergistic effect of salinity and the vegetation land. MPA in sediments depended on the synergistic effect of flow rate and watershed area. Ecological risk assessment identified elevated risks in the eastern study area driven by the presence of polymethyl methacrylate. This study establishes a scientific basis for PRE region MP management and provides global comparative data for estuarine MP research. Full article

Plasticizers and bisphenols are contaminants of concern in the environment, particularly in aquatic ecosystems. Bivalve molluscs are effective bioindicators due to their benthic nature, their ability to filter water, and their capacity to bioaccumulate persistent pollutants. This study analyzes plasticizers and bisphenols in three native clam species (Ruditapes decussatus, Cerastoderma glaucum, and Polititapes aureus) from two Sicilian lagoons under different levels of anthropogenic pressure: the urbanized Capo Peloro lagoon (Ganzirri Lake) and the less impacted Oliveri–Tindari lagoon. The clams, together with water and sediment samples, were collected in winter 2023. Both groups of clams from the two sampling areas contained phthalates such as DMP, DEP, DiBP, and DEHP, as well as non-phthalate plasticizers such as DEHT, DBA, DEA, and DEHA. The sum of non-phthalate plasticizers (NPPs) was consistently higher than the sum of phthalates in all clam samples, confirming the emerging trend of NPPs. This trend was also observed in the water and sediment samples, regardless of the sampling area. The presence of structural analogues of bisphenol A (BPA) highlights the growing prevalence of BPA-like structures in aquatic environments. Given the increasing evidence of widespread and persistent contamination of aquatic environments by plasticizers and bisphenols, it is evident that these substances pose a significant threat to ecosystems and human health. Full article

Mass gatherings such as the annual Hajj pilgrimage in Makkah, Saudi Arabia, generate extreme, short-term anthropogenic emission loads with significant air quality and public health implications. This study assesses the spatiotemporal dynamics of key atmospheric pollutants—including nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), formaldehyde (HCHO), and aerosols—across Makkah and its holy sites before and during the Hajj seasons of 2023 and 2024. Using high-resolution Sentinel-5P TROPOMI satellite data, pollutant fields were reconstructed at 100 m spatial resolution via cloud-based geospatial analysis on the Google Earth Engine. During Hajj 2023, spatially resolved NO₂ concentrations ranged from 15.4 μg/m³ to 38.3 μg/m³ with an average of 24.7 μg/m³, while SO₂ during the 2024 event peaked at 51.2 μg/m³ in key hotspots, occasionally exceeding World Health Organization (WHO) guideline values. Aerosol index values showed episodic surges (up to 1.43), particularly over transportation corridors, parking areas, and logistics facilities. CO concentrations reached values as high as 1069.8 μg/m³ in crowded zones, and HCHO concentrations surged up to 9.99 μg/m³ during peak periods. Quantitative correlation analysis revealed that during Hajj, atmospheric chemistry diverged from urban baseline: the NO₂–SO₂ relationship shifted from strongly negative pre-Hajj (r = −0.74) to moderately positive during the event (r = 0.35), while aerosol–HCHO correlations intensified negatively from r = −0.23 pre-Hajj to r = −0.50 during Hajj. Meteorological analysis indicated significant positive correlations between wind speed and NO₂ (r = 0.35) and wind speed and CO (r = 0.35) during 2024, demonstrating that extreme emission rates overwhelmed typical dispersive processes. Relative humidity was positively correlated with aerosol loading (r = 0.37), pointing to hygroscopic growth patterns. These results quantitatively demonstrate that Hajj drives a distinct, event-specific pollution regime, characterized by sharp increases in key pollutant concentrations, altered inter-pollutant and pollutant–meteorology relationships, and spatially explicit hotspots driven by human activity and infrastructure. The integrated satellite–meteorology workflow enabled near-real-time monitoring in a data-sparse environment and establishes a scalable framework for evidence-based air quality management and health risk reduction in mass gatherings. Full article

Microplastic pollution and herbivory are increasingly recognized as significant stressors in terrestrial ecosystems, yet their interactive effects on native and invasive plants remain poorly understood. In this study, we investigated the individual and combined effects of polyethylene microplastics (PE-MPs) and herbivory by Helicoverpa armigera on the growth and functional traits of twelve plant species (six invasive and six native). Exposure to PE-MPs significantly reduced biomass accumulation, with larger reductions in shoot, root, and total biomass for native plants than for invasive ones. Herbivory also significantly reduced biomass accumulation. When combined, PE-MPs and herbivory produced antagonistic effects on shoot, root, and total biomass. No significant three-way interaction was found among PE-MPs, herbivory, and plant status. Both PE-MPs and herbivory significantly reduced the root mass fraction and root-to-shoot ratio (RSR) while increasing the shoot mass fraction, with the PE-MP-induced reduction in RSR being stronger in native plants. Our findings suggest that multiple anthropogenic stressors can act as ecological filters, reshaping plant competitive dynamics and accelerating community shifts toward stress-tolerant species. Full article

This study focuses on the utilization of ash and slag waste from coal combustion for the production of ceramic construction materials. Detailed chemical and granulometric analyses were performed to determine the multicomponent composition of ash and slag, highlighting its dependence on particle size fractions. The macro- and microelement contents of fresh and aged ash and slag, as well as the coal fuel, were assessed. Significant amounts of SiO₂ (up to 54%), Al₂O₃ (27.5%), Fe₂O₃ (7%), and CaO (6.5%) were found, along with trace elements potentially hazardous to the environment, including Pb, Cu, Mo, and Y. Storage was shown to increase the concentrations of several elements (Pb, Cu, Ga, and Y) due to physicochemical weathering and pollutant migration. Based on comprehensive experimental data, criteria for evaluating ash and slag as raw materials were developed, and new qualitative and quantitative characteristics were identified, demonstrating their feasibility for use in construction material production. These results provide a foundation for systematic monitoring and environmentally responsible utilization of ash and slag waste. Full article

Insect pests impose major economic, agricultural, and public health burdens, damaging crops and transmitting pathogens such as dengue, malaria, and Zika. Conventional chemical control is increasingly ineffective due to insecticide resistance and environmental concerns, prompting a search for innovative strategies. The insect microbiome—comprising both obligate symbionts and environmentally acquired microbes—emerges as a key driver of host physiology and behavior. Microbes influence nutrient acquisition, immunity, reproduction, and chemosensory processing, often to promote their own transmission. By modulating olfactory and gustatory pathways, microbiota can alter host-seeking, mate choice, foraging, and oviposition patterns, reshaping ecological interactions and vector dynamics. These effects are shaped by microbial acquisition routes, habitat conditions, and anthropogenic pressures such as pesticide use, pollution, and climate change. Understanding these multi-directional interactions offers opportunities to design highly specific, microbe-based insect control strategies, from deploying microbial metabolites that disrupt host sensory systems to restoring beneficial symbionts in threatened pollinators. Integrating microbiome ecology with insect physiology and behavior not only deepens our understanding of host–microbe coevolution but also enables the development of sustainable, targeted alternatives to chemical insecticides. This review synthesizes current evidence linking microbiomes to insect biology and explores their potential as tools for pest and vector management. Full article

Marine and freshwater environments are under increasing pressure from anthropogenic stressors. The resulting impacts on exposed ecosystems are complex and challenging to characterise. The effects may be subtle and exhibited over long time periods. Effective and robust approaches are required to characterise the physiological and genetic processes that are impacted by pollutants to assess how populations and ecosystems may be adversely affected and at risk. The objective of the review is to provide an overview of “omics” methodologies used to assess the risk of stressors on exposed biota. This review covers the development of key omics approaches and how they have been used to contribute towards improved knowledge about the effects of environmental stressors, from molecular to whole-organism and community levels of biological organisation. We provide insights into how ecotoxicogenomics approaches can be used for various aspects of environmental risk assessment by characterising toxicological mechanisms of action. This information can be used to confirm cause-and-effect relationships required to better manage risks and protect the integrity and functionality of ecosystems. Full article

Coral reefs are increasingly threatened by global climate change, and mass bleaching and mortality events caused by elevated seawater temperature have led to coral loss worldwide. Hainan Island hosts extensive coral reef ecosystems in China, yet seasonal variation in Symbiodiniaceae communities within this region remains insufficiently understood. We aimed to investigate the temperature-driven adaptability regulation of the symbiotic Symbiodiniaceae community in reef-building corals, focusing on the environmental adaptive changes in its community structure in coral reefs between cold (23.6–24.6 °C) and warm (28.2–30.6 °C) months. Symbiodiniaceae shuffling and rare genotype turnover were discovered in adaptability variations in the symbiotic Symbiodiniaceae community between two months. Symbiodiniaceae genetic diversity increased during warm months, primarily due to temporal turnover of rare genotypes within the Cladocopium and Durusdinium genera. Coral Favites, Galaxea, and Porites exhibited the shuffling of Symbiodiniaceae between tolerant Durusdinium and sensitive Cladocopium. Symbiodiniaceae interactions in G. fascicularis and P. lutea exhibited the highest levels of stability with the increase in temperature, whereas the interactions in A. digitifera and P. damicornis showed the lowest levels of stability. Rare genotypes functioned as central hubs and important roles within Symbiodiniaceae communities, exhibiting minimal responsiveness to temperature fluctuations while maintaining community structural stability. The temperature-driven adaptability regulation of symbiotic Symbiodiniaceae could be achieved by Symbiodiniaceae shuffling and rare genotype turnover. The process might be aggravated by concurrent adverse factors, including elevated salinity, pollution, and anthropogenic disturbance. These findings provide insights into how the Symbiodiniaceae community influences the adaptation and resilience of coral hosts to temperature fluctuations in coral reefs. Furthermore, they may contribute to assessing the reef-building coral’s capacity to withstand environmental stressors associated with global climate change. Full article

Air pollution is causing a global health, climate, and environmental crisis. Air quality (AQ) in hyper-arid regions, such as the Arabian Peninsula, remains under-explored, posing significant concerns for public health and the scientific community. Both long-term and short-term exposure to high pollutant levels, whether from anthropogenic or natural sources, can pose serious health risks. This paper offers a comprehensive review and meta-analysis of urban AQ literature published in the region over the past decade (2013–June 2025). We aim to provide guidance and highlight key directions for future research in the field. This paper examines key pollutants, emission sources, implications of urban sources, and the most studied countries, methodologies, limitations, and recommendations from different case studies. Our analysis reveals a significant research gap highlighting insufficient recent literature. Saudi Arabia was the most studied country with 20 papers, followed by the broader Arabian Peninsula (sixteen), Qatar (twelve), the United Arab Emirates and Iraq (seven each), Kuwait (four), Oman (three), Jordan, and Bahrain (one each). The primary methods employed included measurements and sampling (28%) and remote sensing (24%), with a focus on pollutants such as dust (23.1%), NO_x/NO₂/NO (17.2%), PM_2.5 (17.6%), and PM₁₀ (12%). Industrial emissions (27%) and natural dust (24%) were identified as significant emission sources. Monitoring methods included grab sampling (19%), integrated sampling (34%), and continuous monitoring (47%). Notably, 13.3% of AQ sensors were linked to a station, 27.6% were self-referenced, and 59.1% did not specify calibration methods. The findings highlight the need for further research, regular calibration of air quality monitors, and the integration of advanced modeling approaches. Moreover, we recommend exploring the links between air pollution and urban development to ensure cleaner air and contribute to the global dialogue on sustainable and cross-border AQ solutions. Full article

Water and chemical use in textile dye production are exacerbating water pollution and extraction across Dhaka, Narayanganj, and Gazipur in Bangladesh, where these industries are concentrated. However, the ability to cope with water-related challenges is influenced by multiple factors. This study applies descriptive spatial analysis to map textile dye clusters, river pollution, and water insecurity. As vulnerability is multidimensional and fluctuates across subdistricts, this study develops a Water Vulnerability Index (WVI) consisting of 25 indicators across demographics, socioeconomics, gender, health, WASH, and climate dimensions. The index is based on Multidimensional Vulnerability Assessment (MDVA) and constructed through multicriteria analysis (MCA). The study highlights that the Shitalakhya, Turag-Tongi Khal, Buriganga, and Balu Rivers are highly polluted, with average biochemical oxygen demand (BOD), chemical oxygen demand (COD), and dissolved oxygen (DO) levels exceeding safe limits. Central Dhaka is identified as being extremely water insecure, characterized by significant inequalities in water insecurity across subdistricts. The WVI finds that Gazipur Sadar and Kaliakair subdistricts, housing several textile dye factories, face the highest water vulnerability of the 57 subdistricts. This study furthers the case that Dhaka, Narayanganj, and Gazipur host numerous textile hubs, confront serious water challenges, such as river pollution and water insecurity, and are marked by significant spatial disparities in vulnerability. By exploring anthropogenic pollution alongside multidimensional water vulnerability, this study can inform targeted policy responses, such as stricter regulatory limits, more frequent monitoring and enforcement, and tailored support in high-vulnerability areas. Full article

This study delivers a pioneering, high-resolution hydrogeochemical assessment of surface waters in the Upper Velhas and Upper Paraopeba river basins within Brazil’s Iron Quadrangle—an area of critical socioeconomic importance marked by intensive mining and urbanization. Through a dense sampling network of 315 surface water points (one every 23 km²), the research generates an unprecedented spatial dataset, enabling the identification of contamination hotspots and the differentiation between lithogenic and anthropogenic sources of potentially toxic elements (PTEs). Statistical methods, including exploratory data analysis and cluster analysis, were applied to determine background and anomalous concentrations of potentially toxic elements (PTEs). Geospatial distribution maps were generated using GIS. The results revealed widespread contamination by As, Cd, Cr, Ni, Pb, and Zn, with many samples exceeding Brazilian, European, and global drinking water standards. Arsenic and cadmium anomalies in rural and peri-urban communities raise concerns due to the direct consumption of contaminated water. The innovative application of dense spatial sampling and integrated geostatistical methods offers new insights into the pathways and sources of PTE pollution, identifying specific lithological units (e.g., gold schists, mafic intrusions) and land uses (e.g., urban effluents, mining sites) associated with elevated contaminant levels. By establishing robust regional geochemical baselines and source attributions, this study sets a new standard for environmental monitoring in mining-impacted watersheds and provides a replicable framework for water governance, environmental licensing, and risk management in similar regions worldwide. Full article

The spatial distribution of soil heavy metals was influenced by both natural and anthropogenic factors, and the multi-scale characteristics of heavy metals played a key role in analyzing their influencing factors. Taking arsenic (As) of an oil refining site in Shandong as an example, the As was firstly decomposed into intrinsic mode functions (IMFs) at different scales and a residual using two-dimensional empirical mode decomposition (EMD). Secondly, the spatial variation scales of As, the IMFs, and the residual were quantified by their semi-variograms, respectively. Finally, local spatial correlation analysis and random forest model were employed to analyze the multi-scale features of As, the IMFs, the residual, and environmental variables. The results indicated that the As was decomposed into IMF1, IMF2, IMF3, and a residual using the two-dimensional EMD method, and the corresponding spatial ranges were 72.60 m, 159.30 m, 448.00 m, and 592.36 m, respectively. IMF3 had the highest percentage of variance with a value of 57.56%, indicating that the spatial variation of As was mainly concentrated on a large scale. There were correlations between As and aspect and land use type. However, after the scale decomposition of two-dimensional EMD, there were significant correlations between oil residue thickness and IMF1, land use type and IMF3, land use type, and aspect and residual, respectively. The IMFs and residual had a significant scale–location dependence on environment variables, and the impact of anthropogenic factors on As was mainly reflected at the small and medium scales, while the influence of natural factors was mainly reflected at the large scale. The developed method can provide a methodological framework for the spatial analysis and pollution control of soil heavy metals. Full article