Environments, Volume 11, Issue 4 (April 2024) – 25 articles

This research presents a classification methodology for the detection of new or emerging stress in trees using indices derived from hyperspectral data and tests whether existing hyperspectral indices are effective when used as the classification features for this problem. We tested six existing indices—Water Band Index (WBI), Gitelson–Merzlyak B Index (GMb), Normalized Phaeophytization Index (NPQI), Combined Carotenoid/Chlorophyll Ratio Index (CCRI), Photochemical Reflectance Index (PRI), and Red-Edge Chlorophyll Index (CIre)—along with a seventh Test Index—generated as a composite of PRI and Cire—as classification features. Analysis was conducted using data collected from trees with and without emerald ash borer (EAB) infestation to develop a methodology that could be adapted to measure emerging stress from other pathogens or invasive pests in other tree species. Previous work has focused specifically on the identification of damage or stress symptoms caused by a specific pathogen. In this study, we adapted that work to develop a system of classification that can be applied to the identification of stress symptoms from a range of sources, measurable in trees based on spectral response and, in some cases, detectable prior to the onset of visible symptoms that can be measured through human observation. Our data indicate that existing indices derived from hyperspectral data are effective as classification features when measuring spectral responses indicative of emerging stress in trees. Full article

The maritime industry is addressing environmental issues, and “cold ironing” offers a promising solution. This method involves supplying ships at port with energy, reducing fossil fuel dependence and emissions, and aiding in global climate change efforts. It is especially important for islands like Lesvos, which suffer from high energy costs and environmental issues due to imported fossil fuel reliance. However, research gaps exist in using renewable energy sources (RES) for cold ironing, mainly due to insufficient data on power needs and lack of monitoring for precise calculations and the very limited applications for the case of non-interconnected islands. This study uses real data from the port of Lesvos to evaluate power requirements for cold ironing and assesses the viability of a wind power park for an electrified port with the novelty and uniqueness of developing the application on a non-interconnected island. It also examines potential CO₂ emission reductions. Data from Marine Traffic S.A. were used, considering factors like ship arrivals, hoteling duration, and engine types. This study also includes a simulation using RETScreen software for a 20 MW wind park intended for port operations. The findings show that the monthly energy demand at Mytilene port is around 6118 MWh, with an average power demand of 8.2 MW. The simulated wind park could supply about 72,080 MWh yearly, with a significant surplus (14,956 MWh annually) exportable to the grid. However, demand fluctuations mean the port might need an extra 924 MWh from the main grid. This underscores the need for additional strategies like energy storage and demand–response practices to fully transition to 100% RES-powered operations. Full article

Despite the widespread presence of anthropogenic microparticles (AMs) in beach sediments, research on their occurrence on Moroccan Mediterranean beaches is still limited. This study is the first report on AM pollution in four sandy beaches along the Tetouan coast (Morocco Mediterranean). The findings reveal an average AM concentration of 483.12 ± 157.04 AMs/kg of beach sediment. The most common AM types were fibers (75.54%) and fragments (24.06%). AMs were predominantly black, red, and blue, measuring between 0.1 and 1 mm. The evaluation of the anthropogenic microparticles pollution index (AMPI) and the coefficient of anthropogenic microparticles impact (CAMI) for the study area indicated a “very high abundance” of AMs and an “extreme” level of impact. The polymers identified in these areas included PS, PE, PP, and PET. Tourism, fishing, domestic activities, and poor solid waste management practices are the primary sources of AM pollution in this region. To protect Moroccan beaches, the implementation of a consistent plastic waste management strategy is recommended. Full article

Statistical downscaling of climate data has been widely described in the literature, with the aim of improving the reliability of local climatic parameters from coarse-resolution (often >20 km) global datasets. In this article, we present ClimateDT, a dynamic downscaling web tool for monthly historical and future time series at a global scale. The core of ClimateDT is the 1 km 1981–2010 climatology from CHELSA Climate (version 2.1), where the CRU-TS layers for the period 1901-current are overlayed to generate a historic time series. ClimateDT also provides future scenarios from CMIP5 using UKCP18 projections (rcp2.6 and rcp8.5) and CMIP6 using 5 GCMs, also available on the CHELSA website. The system can downscale the grids using a dynamic approach (scale-free) by computing a local environmental lapse rate for each location as an adjustment for spatial interpolation. Local predictions of temperature and precipitation obtained by ClimateDT were compared with climate time series assembled from 12,000 meteorological stations, and the Mean Absolute Error (MAE) and the explained variance (R²) were used as indicators of performance. The average MAEs for monthly values on the whole temporal scale (1901–2022) were around 1.26 °C for the maximum monthly temperature, 0.80 °C for the average monthly temperature, and 1.32 °C for the minimum monthly temperature. Regarding monthly total precipitation, the average MAE was 19 mm. As for the proportion of variance explained, average R² values were always greater than 0.95 for temperatures and around 0.70 for precipitation due to the different degrees of temporal autocorrelation of precipitation data across time and space, which makes the estimation more complex. The elevation adjustment resulted in very accurate estimates in mountainous regions and areas with complex topography and substantially improved the local climatic parameter estimations in the downscaling process. Since its first release in November 2022, more than 1300 submissions have been processed. It takes less than 2 min to calculate 45 locations and around 8 min for the full dataset (512 records). Full article

Water scarcity has emerged as a pressing global concern, driven by population growth, urbanization, and climate change. As freshwater resources dwindle, the imperative for water reuse becomes increasingly apparent. Reusing water presents a sustainable solution to mitigate scarcity, offering a way to maximize the efficiency of available resources. This review delves into the multifaceted landscape of water consumption and reuse, aiming to provide a comprehensive analysis and understanding of this critical issue. It explores the diverse implications of unregulated water consumption, spanning from its impacts on household routines to its profound influence on economic activities. Additionally, it scrutinizes the legislative framework surrounding water usage, shedding light on the policies and regulations in place. Furthermore, the review investigates the current status of water reuse practices in Europe, delving into various methods of water recovery. Finally, it examines public perceptions and attitudes toward recycled water, offering insights into the societal outlook on this increasingly vital aspect of water management. Full article

Measuring fecal nucleic acid indicators for data normalization can increase costs during wastewater-based epidemiology (WBE). The efficacy of routinely assayed water quality parameters was assessed as an alternative or complement to fecal nucleic acid viral indicator data for their utility in adjusting measured SARS-CoV-2 gene concentrations to improve the relationship between wastewater molecular data and clinical COVID-19 case data. This research covers two study designs: grab samples collected from sewers serving The Ohio State University campus and composite influent samples collected at five wastewater treatment plants (WWTPs) across the state of Ohio. Weekly mandatory clinical testing was used to monitor infections in the student population, and statewide cases were reported through voluntary clinical testing. Statewide WWTP results showed significant strong correlation between SARS-CoV-2 concentrations in the wastewater and confirmed COVID-19 cases, and correlation increased when normalized by flow and additionally increased when normalized by pH, total suspended solids, and temperature, but correlation decreased when normalized by a nucleic acid fecal viral indicator (PMMoV). On campus, correlations were generally not significant unless normalized by PMMoV and/or UV absorbance parameters. Because water quality parameters are routinely assayed at wastewater treatment plants and some may be collected by autosamplers, incorporating wastewater quality data may improve WBE models and could minimize molecular and cellular testing for fecal indicators to decrease costs. Full article

Most research on air chemistry and human health has focused on negative consequences of air pollution from cities, rural dust, mining, or industrial sites. Research on nature tourism and nature therapy, in contrast, focuses on positive benefits of air quality for physical and mental health, e.g., via “clean air clean water” holidays. Aeroanions and terpenoids in forests have received particular attention, especially in China, Japan, and Korea. We review and analyse several hundred articles published in English and Chinese. With a few recent exceptions, English-language research has tested indoor negative ion generators, and concluded that they have no measurable health benefit. It has tested terpenoids in indoor aroma marketing. Chinese-language research, in contrast, has analysed fine-scale components of outdoor environments that affect concentrations of aeroanions and terpenoids: ecosystem, latitude, altitude, temperature, proximity to water, and individual plant species. Historically, health outcomes have been taken for granted, with little rigorous testing. Air quality research has shown that aeroanions can become attached to fine water droplets, e.g., after rain in forests, or in mists produced locally by waterfalls. We hypothesise that the health benefits of aeroanions in natural environments may arise through the scavenging of airborne particulates by negatively charged mists, creating especially clean, dust-free air. We propose that this particularly clean-tasting air, contrasting strongly with polluted urban air, creates positive effects on human mental health and perhaps, also on pulmonary physical health. Mechanisms and outcomes remain to be tested. We also propose testing psychological health effects of airborne terpenoid scents from forest trees. Full article

Phthalic acid esters (PAEs) are a class of ubiquitous and dangerous lipophilic chemicals widely used as additives in various products to improve their physical and chemical properties. Although they have been banned in many countries, their persistence in all environmental compartments is of particular concern. The aquatic environment is especially affected by these compounds because it is strongly influenced both by contamination of anthropic origin and natural contaminants including those produced biosynthetically by some organisms such as algae. In this context, algal organisms can be a source and remedy for phthalate pollution. Both the increase and decrease in uptake and production depend on the physicochemical characteristics of the environment. The dynamics of the natural processes are aimed at achieving an optimal environmental state for their competitiveness and balance of the cellular homeostasis. This review summarizes the studies dealing with biosynthesis and bioaccumulation of phthalates in algae and investigates the source of their origin by suggesting strategies to identify the process leading to their presence. Full article

Heavy metal pollution represents a global health issue. Different methods and technologies are adopted to mitigate the problem of heavy metal pollution. Phytoremediation has been gaining attention as an environmentally friendly method to remediate this problem. The purpose of this research is to explore the effectiveness of phytoremediation in agricultural settings to assess the effect of five soil management practices (chicken manure, sewage sludge, leaf compost, cow manure, and vermicompost) on Cd, Cu, Mo, Ni, Pb, and Zn accumulation in the mustard (leaves and pods) of three mustard Brassica juncea varieties (black mustard, yellow mustard, and mighty mustard). The accumulation in mustard was quantified using the Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The results showed that the bioaccumulation factor (BAF) of the three mustard varieties exceeded one (BAF > 1) for Cd and Mo. It indicates that mustard is a good accumulator of Cd and Mo, whereas BAF values for Cu, Pb, Ni, and Zn were less than one (BAF < 1). The accumulated Cu, Mo, Ni, and Zn levels were below the allowable limit, whereas the Cd and Pb levels were beyond the limit. This result indicates that the investigated mustard varieties can be grown on heavy metal polluted sites for Cd and Mo phytoremediation purposes, but care is needed with regard to Cd and Mo toxicity. Full article

Because of the immense amount of infrastructure in cities, the introduction of vegetation into these constructions is expected to play a critical role in reducing the heat island effect, in mitigating the effects of climate change, and in supporting habitat connectivity and associated biodiversity. Although there is the perception that these solutions can improve the biodiversity of cities, their real value is still unclear. This paper focuses on two aspects of urban greening: green roofs and green walls. It provides a systematic review on biodiversity present in green roofs and walls, through an exhaustive worldwide literature analysis. Arthropods, bats, and birds were the three taxonomic groups analyzed in the papers included in our review. We observed a strong increase in the number of recent publications, thus demonstrating a growing interest in this topic. In summary, we found that green roofs/walls offered additional opportunities for plants and animals to thrive in urban environments because of habitat creation and greater spatial connectivity. In addition, the enhancement of other ecosystem services such as stormwater management and heat island mitigation was noted. By incorporating green features into urban design and planning, cities can support biodiversity while also improving the overall sustainability and livability of urban spaces. Full article

About 2.5 billion people rely on groundwater as their main drinking water source, and arsenic pollution within the groundwater system can cause serious short- and long-term health issues. Within the natural environment, arsenic generally exists as oxyanions which have two oxidation states, As(III) and As(V). Under ambient pH conditions, As(V) is primarily present as an anion (i.e., H₂AsO₄⁻) while As(III) tends to be uncharged (i.e., H₃AsO₃), making it much more difficult to remove As(III) through existing treatment techniques such as adsorption and reverse osmosis (RO). In Eastern Wisconsin, the dolomite and dolomite/sandstone aquifers represent a major drinking water source and high arsenic concentrations have been observed. Previous studies showed that arsenic can be released into private drinking water wells due to the oxidation of sulfide-bearing minerals with arsenic impurities that are usually dispersed within the dolomite and sandstone bedrock. However, there is a lack of information on the concentrations of each arsenic species as well as arsenic dynamics during water pumping/usage. The primary goals of this research were (1) to quantify the baseline concentrations of each arsenic species within selected Eastern Wisconsin private drinking water wells, and (2) to determine how the arsenic concentrations and species could be affected by continuous water usage. Our results showed that As(III) was the dominant species of arsenic, and during continuous water usage, there could be an upward trend in arsenic concentration (there was minimal change in arsenic speciation). Upon the completion of water pumping, arsenic concentrations decreased over time and returned to pre-pumping levels. Our findings highlighted the importance of quantifying the speciation and dynamics of arsenic during water use to the assessment of public health risks and the design of appropriate water treatment techniques. Full article

Spatiotemporal variations of phytoplankton populations in agricultural irrigation ponds need to be accounted for in order to properly assess water quality. Phytoplankton cell and photosynthetic pigment concentrations are two common metrics used to characterize phytoplankton communities. This work evaluated depth and time of the day as factors affecting discrete sampling of phytoplankton. The abundance of chlorophytes, diatoms, cyanobacteria, flagellates, and dinoflagellates, as well as chlorophyll-a and phycocyanin pigments, were determined in samples taken at the surface and depth, in 0.5 m increments, in three to five spatial replications at 9 a.m., 12 p.m., and 3 p.m. in two ponds in Maryland, USA. Depth was a significant factor for photosynthetic pigment concentration variations in both ponds on most sampling dates and time of day was a significant factor for photosynthetic pigment concentrations in half of the sampling dates. Depth was not a significant factor in cell concentration variations for any of the phytoplankton groups observed, but time of day was a significant factor in 40% of the sampling dates. Two distinct patterns in pigment concentration daily variation were observed. The first featured a continuous increase with depth throughout the day. The second showed maximum concentrations at the surface in the morning changing to maximum concentrations at 0.5 m depth at 12 p.m. and 3 p.m.; these patterns corresponded to different morning solar irradiance levels. This indicates that sampling depth and time can be a significant factor when evaluating photosynthetic pigments and should be accounted for in monitoring programs that rely on pigments for decision-making. Full article

This study aimed to assess soil organic carbon (SOC) concentration and stock in mineral soils in cropland and grassland in Latvia, considering soil groups and texture classes. It covered 197 sites across Latvia (152 in cropland, 45 in grassland). Soil profile description and sampling (at depths of 0–10 cm, 10–20 cm, and 20–40 cm) were conducted between 2021 and 2023. Laboratory analyses included soil bulk density (SBD), total carbon (TC), total nitrogen (TN), carbonate content, pH, and extractable phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). SOC stock was calculated, and correlations with other soil parameters were determined. In cropland sites, Arenosols and Stagnosols had the lowest SOC concentration and stock, while Gleysols and Phaeozems had the highest. In grassland sites, Retisols exhibited the lowest SOC concentration in the 0–20 cm layer, while Planosols had the highest SOC concentration in this layer. Conversely, in the 20–40 cm layer, Retisols showed the highest SOC concentration, while Gleysols had the lowest concentration. Regarding SOC stock in grassland sites, Planosols exhibited the highest values, while the lowest values were observed for Retisols and Umbrisols. Contrary to our hypothesis that grassland exhibits higher SOC stock than cropland, our results show the reverse for Phaeozems, the dominant WRB soil group in this study: a higher average SOC concentration and stock in cropland compared to grassland. However, very low occurrence of some soil groups and lack of some soil groups for grassland sites hinders the correct interpretation of these results, and further investigations are required in future studies. Full article

Florida Bay, a large and shallow estuary, serves as a vital habitat for a diverse range of marine species and holds significant environmental, commercial, and recreational value. The salinity structure of the bay plays a key role in the bay’s ecosystem. Florida Bay receives 45% of its freshwater directly from rainfall, the largest source of freshwater, while the Taylor River is the second largest source. A hydrodynamic model was applied to determine if doubling the Taylor River flow, as currently planned, is adequate to meet salinity performance measures and protect the bay’s ecosystem health. Model-predicted salinity indicated that rainfall caused the largest reduction (10–15 ppt) followed by Taylor River discharges, and none of the predicted salinity scenario means exceeded 38 ppt. The salinity restoration target was achieved more than 70% of the time, by doubling the Taylor River freshwater discharges, only for the existing bay conditions. To protect Florida Bay’s ecosystem health and counterbalance saltwater intrusion in the Everglades wetlands, caused by future sea-level rise, additional freshwater sources needs to be identified. Yet, the question becomes, do we have enough available freshwater sources to achieve the restoration target and protect the bay’s ecosystem health now and for future sea-level rise? Full article

The conventional Haber–Bosch process (HBP) for NH₃ production results in CO₂ emissions of almost 400 Mt/y and is responsible for 1–2% of global energy consumption; furthermore, HBP requires large-scale industrial equipment. Green or e-ammonia produced with hydrogen from alkaline water electrolysis using renewable energy and nitrogen from the air is considered an alternative to fossil-fuel-based ammonia production. Small-scale plants with the distributed on-site production of e-ammonia will begin to supplant centralized manufacturing in a carbon-neutral framework due to its flexibility and agility. In this study, a flexible small-scale NH₃ plant is analyzed with respect to three steps—H₂ generation, air separation, and NH₃ synthesis—to understand if milder operating conditions can benefit the process. This study investigates the aspects of flexible small-scale NH₃ plants powered by alkaline electrolyzer units with three specific capacities: 1 MW, 5 MW, and 10 MW. The analysis is carried out through Aspen Plus V14 simulations, and the primary criteria for selecting the pressure, temperature, and number of reactors are based on the maximum ammonia conversion and minimum energy consumption. The results show that: (i) the plant can be operated across a wide range of process variables while maintaining low energy consumption and (ii) alkaline electrolysis is responsible for the majority of energy consumption, followed by the ammonia synthesis loop and the obtention of N₂, which is negligible. Full article

Innovative management practices are needed to mitigate greenhouse gas (GHG) emissions from the agricultural sector by enhancing soil carbon (C) and nitrogen (N) stocks, which serve as major reservoirs of C and N in the terrestrial ecosystem. The effect of cropping systems and N fertilization rates were examined on soil organic C (SOC) and soil total N (STN) stocks at the 0–120 cm depth from 2011 to 2018 in a dryland farm in the US northern Great Plains. Cropping systems were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), no-till spring wheat–pea (Pisum sativum L.) (NTWP), no-till spring wheat–fallow (NTWF), and conventional till spring wheat–fallow (CTWF) and N fertilization rates were 0, 50, 100, and 150 kg N ha⁻¹ applied to spring wheat. The SOC and STN were greater for NTWP than other cropping systems at most N fertilization rates and depth layers. Increasing N fertilization rate increased SOC at 0–30 cm for NTWP and NTCW, but had a variable effect on STN for various cropping systems and soil depths. The NTWP with 50–100 kg N ha⁻¹ can enhance SOC and STN at 0–30 cm compared to other cropping systems and N fertilization rates in the US northern Great Plains. Full article

German noise action plans aim to reduce negative health outcomes from noise exposure and identify quiet areas free of noise pollution. Quiet area identification in German noise action plans is based primarily on noise mapping and spatial analysis and not empirical or qualitative data about acoustic environments, thus leaving a gap in the understanding of the quality of formally recognized quiet areas in noise action plans. This work presents a comparative empirical case study in Dortmund, Germany, with the aim to describe the diurnal dB(A) and biophonic properties of quiet areas versus noise ‘hot spots’. Sound observations (n = 282,764) were collected in five different natural or recreational land use patch types larger than four acres within 33 proposed quiet areas in Dortmund (n = 70) and 23 noise hot spots between 27 April 2022 and 2 March 2023. We found that quiet areas are on average more than 20 dB(A) quieter than noise hot spots almost every hour of the day. Forests, managed tree stands, cemeteries, and agriculture diel patterns are dominated by dawn dusk chorus in spring and summer, whereas sports and recreation as well as noise hot spots are dominated by traffic and human noise. A novel composite biophony mapping procedure is presented that finds distinct temporal distribution of biophony in forested and agriculture peri-urban locations positively associated with patch size, distance away from LDEN > 55, proximity to water, and the number of vegetation layers in the plant community. Anthrophony distribution dominates urban land uses in all hours of the day but expands during the day and evening and contracts at night and in dusk hours. The procedures presented here illustrate how qualitative information regarding quiet areas can be integrated into German noise action planning. Full article

Africa has a lower proportion of urban areas compared to other continents, yet it is experiencing rapid urbanization, which is posing a significant threat to the urban ecosystem. This study presents the results of a bibliometric analysis from publications on urban green spaces (UGS) research in African cities. From the Web of Science, Science Direct, Google Scholar, and PubMed databases, 264 articles on UGS research in Africa were included in this study. This research topic experienced rapid growth, as more than 68% of all the articles were produced in the past five years, where about 63% of the studies included in this analysis were carried out in only four countries. Most of the studies were carried out at the intracity scale, with the main focus being on the ecosystem services provided by UGS. Change detection and overall UGS mapping studies show that high-income cities have a high percentage of UGS, while many African cities exhibited lower green coverage. We commend the work from researchers; however, there is still a gap to fill both in terms of high-quality datasets and state-of-the-art technology usage, and there is also a need for more comparative studies among cities and countries at the continental scale. Full article

Agriculture is the main economic activity of Mozambique and there is a lack of information about the quality of agricultural soils. In this paper, five soils from the Manica and Sussundenga districts (Manica province) sampled in the years 2021/2022 and 2022/2023 (before and after the rainy seasons) were subjected to an agronomical and environmental chemical analysis to assess their quality, from the fertility and environmental contamination points of view. Standard analytical methodologies from external certified laboratories and local X-ray fluorescence measurements were used. All the studied soils were acidic (pH ranging from 4.5 to 5.4), had no salinity problems (conductivity ranging from 4.2 to 11.8 mS/m), and had a low amount of soil organic matter (0.90% to 1.81%). Soils from the Sussundenga district had a very low cation exchange capacity (CEC) (average of 3.33 cmol_c/kg), while that of those from the Manica district ranged from very low to average CEC (3.59 to 13.11 cmol_c/kg). Sussundenga soils also had a phosphorous deficiency (values ranging from <20 to 38.5 mg/kg) and there were deficiencies and/or excesses of some macro and micronutrients in all soil samples. Manica soils were contaminated, apparently from geogenic origin, with Cr (280 to 1400 mg/kg), Co (80 mg/kg), Ni (78 to 680 mg/kg) and V (86 mg/kg). Agricultural soil monitoring must be fostered in Mozambique in order to improve food quality and quantity to ensure economic and environmental sustainability. Full article

Environmental DNA (eDNA) is widely used for detecting target species, including monitoring endangered species and detecting the presence of invasive species. Detecting targeted species using the eDNA approach is typically carried out with species-specific qPCR assays. Amazon frogbit (Limnobium laevigatum) is classified as a State-Prohibited Matter Weed in NSW, Australia. It is a fast-growing perennial aquatic weed that outcompetes native aquatic plants, leading to a reduction in the habitats of aquatic animals. Early detection is crucial for the effective management of this species. In this study, we developed a qPCR assay for L. laevigatum based on the rpoB gene sequence. This assay was validated against 25 non-target aquatic and terrestrial species. It was found to be species-specific, with the positive signal exclusively detected in L. laevigatum. The assay was highly sensitive with the modelled detection limits of 3.66 copies of DNA/µL. Furthermore, our assay was validated using environmental samples collected from field sites with and without the presence of L. laevigatum. Our assay is an effective tool for targeted eDNA detection of L. laevigatum, which will enhance efforts to monitor and control this invasive aquatic weed. Full article

Iron (Fe) is one of the main nutrients present in dissolved, suspended, and colloidal states in river water. Predicting the composition and size of dissolved Fe compounds is crucial for assessing water quality. In this stud, we used a combination of physical methods (filtration), chemical techniques (ion exchange chromatography), and thermodynamic modeling (Visual MINTEQ) to characterize dissolved Fe speciation in boreal organic-rich rivers across a sizable south–north transect. We chose contrasting rivers with a predominance of either allochthonous or autochthonous organic compounds. We found that the dissolved organic matter (DOM) in the studied rivers varies in molecular weights and the degree of humification. Regardless of the climate parameters of the river watershed, the dominant status of dissolved Fe during the summer low-water period was essentially colloidal and dominated by anionic complexes of the type [MeL]ⁿ⁻. Full article

This study aims to assess the impact of HydroBreak PLUS biosurfactant on the phytoremediation of diesel-contaminated soil by three legume plant species: Medicago sativa, Lotus corniculatus, and Melilotus albus. Legumes were grown in soil contaminated with diesel (4.0 g kg⁻¹, 6.0 g kg⁻¹) for 90 days, and the changes in soil diesel and nutrient concentrations, plant growth, and physiological parameters were measured. Diesel negatively affected the biomass production of all legumes, though the reduction in growth rate was observed only in L. corniculatus and M. albus. L. corniculatus had the highest diesel removal rate of 93%, M. albus had the lowest of 87.9%, and unplanted treatments had significantly lower diesel removal rates (up to 66.5%). The biosurfactant mitigated diesel-induced reduction in plant shoot and root weight and an increase in L. corniculatus root biomass (24.2%) were observed at 4.0 g kg⁻¹ diesel treatment. The use of biosurfactant accelerated diesel removal from the soil, though the effect was diesel soil concentration and plant species-dependent. In unplanted treatments, the diesel removal rates increased by 16.4% and 6.9% in the treatments with 4 and 6 mg kg⁻¹, respectively. The effect of biosurfactants on diesel removal by plants was less pronounced and reached 4.6% and 3.2% in the treatments with 4 and 6 mg kg⁻¹, respectively. The study revealed that the phytoremediation efficiency could not be directly linked to plant physiological parameters as only M. sativa changes in plant growth corresponded well with photosystem II performance. Implementation of legumes and biosurfactants has a positive effect on soil quality by its enrichment with inorganic P and soluble phenols, while no enrichment in NO₃⁻ and NH₄⁺ was observed. Full article

This study focuses on the impact of wildfire smoke emissions on regional, urban air quality during a wildfire event. We measured volatile organic compounds (VOCs) and fine particulate matter (PM_2.5) in the San Francisco Bay Area to assess air quality during a wildfire event and compared them to those in a later non-wildfire period. VOCs were collected using thermal desorption tubes and quantified using thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Elevated concentrations of VOCs such as 1,3,5-trimethylbenzene (0.33 ± 0.01 µg/m³), benzene (1.03 ± 0.02 µg/m³), toluene (2.15 ± 0.04 µg/m³), ethylbenzene (0.60 ± 0.02 µg/m³), and m, p-xylene (0.77 ± 0.07 µg/m³) were observed in the wildfire event. Compared with that in the non-wildfire season, the toluene concentration during the wildfire period was more than three times the non-wildfire concentration. Similarly, the benzene concentration during the wildfire was almost four times higher, and that of p, m-xylene was three times higher. The higher wildfire levels were statistically significant for sec-butylbenzene, 1,2,4-trimethylbenzene, n-propylbenzene, o-xylene, styrene, 1,3,5-trimethylbenzene, benzene, toluene, ethylbenzene, and p,m-xylene (p < 0.00001). These higher VOC levels compared with those for the non-fire period may potentially pose a public health concern. Open face passive sampler (OFPS)-collected PM was analyzed using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and revealed organic carbon tar balls. The highest daily average beta-attenuation-monitored PM_2.5 during the fire period was 200 µg/m³ and the highest hourly average was 270 µg/m³. Monitoring gas phase species in addition to PM concentrations is useful during wildfire season to inform public health guidance. Full article

Wastewater-based epidemiology (WBE) has emerged as a key method for the continuous monitoring of COVID-19 prevalence including circulating SARS-CoV-2 lineages. WBE addresses the limitations of traditional clinical COVID-19 surveillance such as clinical test availability, fluctuating testing rates, and increased reliance on rapid antigen tests. Our study in Perth, Western Australia found a significant positive correlation between SARS-CoV-2 concentrations in wastewater and clinical PCR positivity rates (rs = 0.772; p < 0.001) over an 18-month period that included four successive COVID-19 waves. A strong positive correlation was apparent between the proportions of SARS-CoV-2 lineages in wastewater and clinical cases within the same region (rs = 0.728, p < 0.001), including earlier detection of Omicron and recombinant lineages in wastewater before clinical case confirmation. The successful integration of WBE with healthcare data underscores its critical role in enhancing public health decision-making and pandemic management. This approach not only demonstrates the value of WBE in current global health surveillance efforts but also highlights the potential of WBE to address future public health challenges, as a comprehensive disease monitoring and response approach. Full article

The Taklimakan Desert in northwest China stands as a significant contributor to dust storms, with its fringe oases already designated as ecologically fragile due to the severe impacts of these storms. This study focuses on Moyu County, situated on the southwest edge of the Taklimakan Desert, examining the origin and transport pathways of dust storms from 2004 to 2021. The classification involves utilizing a 36 h backward trajectory model and the k-means clustering technique, resulting in three clusters displaying distinct transport pathways and entry directions. Air pollutant concentrations at the study site corresponding to each cluster are analyzed to elucidate the contribution of dust storms from different directions. The results categorize 1952 dusty days into three categories: NE-SE (cluster 1), N-N (cluster 2), and NW-W (cluster 3). The highest frequency of dust storms, accounting for 64% of the total suspended dust weather, originates from the northeast and southeast direction (NE-SE category), with relatively weak intensity, mainly as suspended dust (71.5%). Strong sand storms predominantly occur from the northwest direction (57.8%). Cluster 1 (the southeast direction) exhibits a higher concentration of SO₂, NO₂, and CO, mainly associated with its pathway over anthropogenically polluted areas. Conversely, Cluster 3 (northwest direction) shows higher PM10 and PM2.5 concentrations due to increased wind speed and stronger dust storm intensity. The study develops dust storm early warning schemes based on 15-day advance predictions, utilizing an 18-year trajectory model and local monitoring data. This proposed warning scheme serves as a predictive tool for potential dust storm events and air pollution levels, aiding in both scientific research and policy formulation for dust storm mitigation and adaptation. The data obtained also hols relevance for conducting further scientific research in this field. Full article