Search Results (22)

Malaria persists as a paradigmatic model of co-evolutionary complexity, emerging from the dynamic interplay among a human host, Anopheles vectors, and Plasmodium falciparum parasites. In human populations, centuries of selective pressures have sculpted an intricate and heterogeneous immunogenetic landscape. Classical adaptations, such as hemoglobinopathies, are complemented by a diverse array of genetic polymorphisms that modulate innate and adaptive immune responses. These genetic traits, along with the acquisition of functional immunity following repeated exposures, mitigate disease severity but are continually challenged by the parasite’s highly evolved mechanisms of antigenic variation and immunomodulation. Such host adaptations underscore an evolutionary arms race that perpetually shapes the clinical and epidemiological outcomes. Intermediaries in malaria transmission have evolved robust responses to both natural and anthropogenic pressures. Their vector competence is governed by complex polygenic traits that affect physiological barriers and immune responses during parasite development. Recent studies reveal that these mosquitoes exhibit rapid behavioral and biochemical adaptations, including shifts in host-seeking behavior and the evolution of insecticide resistance. Mechanisms such as enhanced metabolic detoxification and target site insensitivity have emerged in response to the widespread use of insecticides, thereby eroding the efficacy of conventional interventions like insecticide-treated bed nets and indoor residual spraying. These adaptations not only sustain transmission dynamics in intervention saturated landscapes but also challenge current vector control paradigms, necessitating the development of innovative, integrated management strategies. At the molecular level, P. falciparum exemplifies evolutionary ingenuity through extensive genomic streamlining and metabolic reconfiguration. Its compact genome, a result of strategic gene loss and pruning, is optimized for an obligate parasitic lifestyle. The repurposing of the apicoplast for critical anabolic functions including fatty acid, isoprenoid, and haem biosynthesis highlights the parasite’s ability to exploit host derived nutrients efficiently. Moreover, the rapid accumulation of mutations, coupled with an elaborate repertoire for antigenic switching and epigenetic regulation, not only facilitates immune escape but also accelerates the emergence of antimalarial drug resistance. Advanced high throughput sequencing and functional genomics have begun to elucidate the metabolic epigenetic nexus that governs virulence gene expression and antigenic diversity in P. falciparum. By integrating insights from molecular biology, genomics, and evolutionary ecology, this study delineates the multifaceted co-adaptive dynamics that render malaria a recalcitrant global health threat. Our findings provide critical insights into the molecular arms race at the heart of host–pathogen vector interactions and underscore promising avenues for the development of next generation therapeutic and vector management strategies aimed at sustainable malaria elimination. Full article

The dynamic relationship between microplastics (MPs) in the air and on the Earth’s surface involves both natural and anthropogenic forces. MPs are transported from the ocean to the air by bubble scavenging and sea spray formation and are released from land sources by air movements and human activities. Up to 8.6 megatons of MPs per year have been estimated to be in air above the oceans. They are distributed by wind, water and fomites and returned to the Earth’s surface via rainfall and passive deposition, but can escape to the stratosphere, where they may exist for months. Anthropogenic sprays, such as paints, agrochemicals, personal care and cosmetic products, and domestic and industrial procedures (e.g., air conditioning, vacuuming and washing, waste disposal, manufacture of plastic-containing objects) add directly to the airborne MP load, which is higher in internal than external air. Atmospheric MPs are less researched than those on land and in water, but, in spite of the major problem of a lack of standard methods for determining MP levels, the clothing industry is commonly considered the main contributor to the external air pool, while furnishing fabrics, artificial ventilation devices and the presence and movement of human beings are the main source of indoor MPs. The majority of airborne plastic particles are fibers and fragments; air currents enable them to reach remote environments, potentially traveling thousands of kilometers through the air, before being deposited in various forms of precipitation (rain, snow or “dust”). The increasing preoccupation of the populace and greater attention being paid to industrial ecology may help to reduce the concentration and spread of MPs and nanoparticles (plastic particles of less than 100 nm) from domestic and industrial activities in the future. Full article

The chemistry of atmospheric precipitation serves as an important proxy for discriminating the source(s) of air contaminants in urban environments as well as to discuss the dynamic of atmospheric chemistry exchanges. This approach can be undertaken at time scales varying from single events to seasonal and yearly time frames. Here, we characterized the chemical composition of two single rain episodes (18 July 2018 and 21 February 2019) collected in Wrocław (SW Poland). Our results demonstrated inner variations and seasonality (within the rain event as well as between summer and winter), both in ion concentrations as well as in their potential relations with local air contaminants and scavenging processes. Coupling statistical analysis of chemical parameters with meteorological/synoptic conditions and HYSPLIT back trajectories allowed us to identify three main factors (i.e., principal components; PC) controlling the chemical composition of precipitation, and that these fluctuated during each event: (i) PC1 (40%) was interpreted as reflecting the long-range transport and/or anthropogenic influences of emission sources that included biomass burning, fossil fuel combustion, industrial processes, and inputs of crustal origin; (ii) PC2 (20%) represents the dissolution of atmospheric CO₂ and HF into ionic forms; and (iii) PC3 (20%) originates from agricultural activities and/or biomass burning. Time variations during the rain events showed that each factor was more important at the start of the event. The study of both SO₄²⁻ and Ca²⁺ concentrations showed that while sea spray inputs fluctuated during both rain events, their overall impact was relatively low. Finally, below-cloud particle scavenging processes were only observed for PM₁₀ at the start of the winter rain episode, which was probably explained by the corresponding low rain intensity and an overlap from local aerosol emissions. Our study demonstrates the importance of multi-time scale approaches to explain the chemical variability in rainwater and both its relation to emission sources and the atmosphere operating processes. Full article

Swahili coastal forests, spanning the Kenyan and Tanzanian coastlines and the Zanzibar Archipelago, are integral to the biodiverse Eastern Arc and Coastal Forest region. These forest ecosystems face considerable anthropogenic threats. This study contributes to the available knowledge on the floral composition and plant community assemblages of Mnemba Island, a small sandy cay in the Zanzibar Archipelago, which helps to establish baseline data for conservation purposes. Two main coastal forest plant communities were identified: (1) the Casuarina cunninghamiana–Suriana maritima open to closed sandy dry coastal forest, and (2) the Eugenia capensis–Mimusops obtusifolia coastal forest. A total of 91 different plant species belonging to 54 plant families were identified for the island. Community 2, an indigenous forest, supports diverse bird breeding colonies and is a crucial habitat for the threatened Aders’ duiker. Understory development is limited due to the historical Suni antelope overpopulation. Environmental factors like salt spray, allelochemicals, herbivore browsing, and climate fluctuations influence the vegetation abundance and composition. The study underscores differences in species diversity and composition between the planted Casuarina community and the natural atoll vegetation. The natural vegetation shows affinities with the Zanzibar–Inhambane edaphic coral-rag scrub forest and the transitional rainforest. Several species characteristic of Indian Ocean atolls were identified, providing insights into invasion ecology and conservation strategies. The study contributes conceptually to our understanding of vegetation dynamics in island ecosystems by highlighting the interplay between plant communities, environmental processes, and human activities. The fragile yet resilient nature of Mnemba’s unique ecosystem is emphasised, offering insights for conservation management, long-term monitoring, and adaptive approaches tailored to island environments. Full article

Antimicrobial resistance (AMR) has become a world-wide health issue, and anthropogenic antibiotics entering the environment is cause for concern with regard to impacts on environmental bacteria. As water resources have become scarcer, reuse of wastewater treatment plant (WWTP) effluent has increased, creating a conduit for environmental antibiotic pollution. The aim of this study was to determine the impact of spray-irrigating effluent on the incidence of AMR in soil organisms in agricultural lands (Astronomy Site, Pennsylvania State University). This study performed culture work to assess resistance of Gram-negative and Gram-positive soil bacteria to four antibiotics (sulfamethoxazole, trimethoprim, ciprofloxacin, and ampicillin) and molecular work (qPCR) to quantify genes associated with AMR (sulI, sulII, ermB, and intI1). Compared to a control site, Gram-negative bacteria at the Astronomy Site appeared to have increased resistance to sulfamethoxazole and trimethoprim. Higher numbers of resistance genes by depth (below 35 cm) and by location were consistently observed at the Astronomy Site with copy numbers of some genes up to 10⁶-fold higher than the control site. Increased quantities of sulI and intI1 in the top 0–5 cm of the soil profile appeared to be dependent upon the amount of effluent irrigation received, whereas the presence of sulII and ermB showed the opposite patterns. Overall, long-term reuse of WWTP effluent to spray irrigate cropped lands does appear to alter and possibly increase AMR in soil environments; however, additional work is necessary to determine potential impacts on human, wildlife, plant, and soil health. Full article

This critical review examines the release of pesticides from agricultural practices into the air, with a focus on volatilization, and the factors influencing their dispersion. The review delves into the effects of airborne pesticides on human health and their contribution to anthropogenic air pollution. It highlights the necessity of interdisciplinary research encompassing science, technology, public policy, and agricultural practices to effectively mitigate the risks associated with pesticide volatilization and spray dispersion. The text acknowledges the need for more research to understand the fate and transport of airborne pesticides, develop innovative application technologies, improve predictive modeling and risk assessment, and adopt sustainable pest management strategies. Robust policies and regulations, supported by education, training, research, and development, are crucial to ensuring the safe and sustainable use of pesticides for human health and the environment. By providing valuable insights, this review aids researchers and practitioners in devising effective and sustainable solutions for safeguarding human health and the environment from the hazards of airborne pesticides. Full article

The concentrations of trace elements in atmospheric bulk depositions (wet plus dry) were investigated from two highly industrialised areas of Sicily (southern Italy) from June 2018 to July 2019, in order to recognise the main natural and anthropogenic sources. A side objective of this study was to improve the common sampling procedures and analytical methods used for monitoring trace elements in atmospheric deposition. The trace element VWM (Volume-Weighted Mean) concentrations ranged from less than 0.01 μg L⁻¹ for trace elements such as Cs, Tl, and U, up to 24 μg L⁻¹ for minor elements (Al, Zn, Sr), in the filtered aliquot, while they reached concentrations up to 144 μg L⁻¹ for the same elements, in the unfiltered aliquot. Therefore, significant differences in concentrations between these two aliquots were found, particularly for Al, Fe, Ti, Zn, Cr, Pb, Se, Cs, and U. This implies that filtering operations may produce a consistent underestimation of concentrations of certain ‘constituents’ of the atmospheric deposition. Natural (marine spray, local and regional geogenic input, volcanic emanations) and anthropogenic sources (industrial emissions, auto vehicular traffic, and diffuse background pollution) which influence rainwater chemistry were identified. Enrichment factors (EFs), with respect to the upper crust composition, provided clear evidence of the different sources above mentioned: Ti, Fe, Al, Cs, Cr, Rb, and Co have low EFs (<1), and are referable to the (local and/or regional) geogenic input, while Se, Sb, Zn, B, Cd, Cu, Mo, Sr, As, with high EFs (>10), highlight the influence of marine and/or industrial sources. The study produced a novel dataset on the atmospheric deposition rate of several trace elements, which had never been studied in the investigated areas. Finally, a comparison of trace element deposition rates in the studied areas with the atmospheric deposition reported for 53 different sites, belonging to 20 different European nations, was made. The comparison showed that some elements, such as Al, V, Zn, and Mo had higher median deposition fluxes in the Sicilian sites than in European monitoring sites. Full article

Plants can absorb only 30 to 40% of nutrients from the soil through the root system because the absorption process depends on soil properties, wheatear conditions, and the plant’s species. Therefore, foliar fertilization using macro- and micronutrients has proven to be an excellent alternative. Herein, we evaluated the foliar application of a neutralized sulfuric bone meal hydrolysate (NSBMH) on soybean growth parameters, pod yield, nitrogen, phosphorus, and chlorophyll pigment concentrations under greenhouse conditions. A complete randomized block design was performed, and each block contained three treatments: 1% NSBMH, commercial fertilizer, and negative control. After 90 days of growth, soybean plants foliar-sprayed with 1% NSBMH improved significantly (p < 0.05) in terms of foliar area, plant fresh mass, plant dried mass, plant height, nitrogen, and chlorophyll a + b concentrations, while trifoliar leaf number, pod number, and pod fresh and dried masses were higher but not significant, and phosphorus concentration maintained suitable levels when compared to the negative control treatment. Additionally, the 1% NSBMH group presented similar and higher values, but not significant (p > 0.05), on the evaluated traits versus the commercial fertilizer treatment. Consequently, cattle bone recycling for the obtainment of alternative phosphorus as neutralized sulfuric bone meal hydrolysate is an excellent choice because it encourages the reutilization of anthropogenic waste, such as cattle bone waste, which protects the environment and reduces the soil and foliar application of mineral phosphoric fertilizers and reduces dependency on the main unsustainable fertilizer suppliers. Full article

This paper presents experimental research findings on the gas composition of pyrolysis and combustion products of typical forest fuels (leaves, needles, twigs, a mixture of these, and timber). These experiments were performed for the combustion and application of a fire extinguishing agent to a pyrolyzing material. Water, a bischofite solution, a bentonite slurry, and a foaming agent solution were utilized. Two gas analysis systems were used, as follows: an industrial one based on CO₂, CO, H₂, CH₄, and O₂ sensors and a scientific one (a gas analyzer with H₂, CH₄, H₂S, SO₂, CO, and CO₂ sensors). Fires were extinguished by using two common techniques, as follows: continuous liquid supply and cycling spraying. The comparative efficiency of applying a group of fire extinguishing agents to forest fires was estimated, taking account of liquid consumption, suppression time, and environmental pollution. A method was proposed for calculating the relative efficiency factors of fire extinguishing agents when containing and suppressing forest fires, allowing for the consumed time, resources, and anthropogenic emissions. Full article

Aerosol particles in coastal areas result from a complex mixing between sea-spray aerosols locally generated at the sea surface by breaking waves and a continental component issued from natural and/or anthropogenic sources. The aim of this paper is to study how the aerosols mix in the coastal marine atmosphere to evaluate the impact of the background pollution on the atmospheric aerosols. To this end, we have carried out a qualitative analysis of particulate matter sampled at two French coastal areas using a non-destructive methodology combining scanning electron microscopy (SEM)/X-ray fluorescence, transmission electron microscopy (TEM), X-ray diffraction, and Raman spectroscopy. Our analysis shows a dominant contribution of anthropogenic aerosols through strong levels of submicronic carbon soot and sulfate particles, even observed when the aerosol is sampled during pure maritime-air mass episodes. Our results also evidence the non-mixing between sea-spray, mainly composed of coarse aerosol particles, and this anthropogenic particulate matter of smaller sizes. Full article

Air particulate matter with a diameter of 2.5 µm (PM_2.5) were assembled for a whole year from the historical Jeddah district. Additional PM_2.5 aerosols were collected during the autumn and winter seasons from another newly constructed district in Jeddah city (Alnaeem). The annual concentration of the total mass of the PM_2.5 aerosols from the historical Jeddah site was found to be 43 ± 6 µg/m³. In addition, the average of the total mass concentration at the Alnaeem site was 61 ± 14 µg/m³. These values were greater than the annual mass concentration of the air quality standards of the European Commission (25 µg/m³) and the World Health Organization (10 µg/m³). The elemental analysis of the collected fine atmospheric aerosols was achieved by energy dispersive X-ray fluorescence (EDXRF) with three secondary targets (CaF₂, Ge, and Mo). Quantitative elemental analyses of twenty-two (22) elements were achieved starting from the low atomic number element (Na) up to the high atomic number element (Pb). Although the historical Jeddah site is not well organized, the elemental concentrations and total mass concentrations were lower than those of the other site. The statistical analyses including enrichment factors, correlation analysis, and the principal component analysis revealed more information about the source identification of the PM_2.5 aerosols collected from both locations. It was recognized that the elements Al, Si, K, Ca, Ti, Mn, Fe, Rb, and Sr originated from a natural source. On the other hand, the elements Ta, Br, Pb, Sc, Ni, Cu, Zn, and S originated from anthropogenic sources. Finally, the elements Na, Cl, and Br came mainly from the sea spray source. Full article

The concentrations of total suspended particles (TSPs) on four buildings near a steel plant’s bulk material storage site for iron ore, coal, limestone, and sinter were evaluated for summer and winter, where the concentrations were 58 (17–55) μg m⁻³ and 125 (108–155) μg m⁻³, respectively. A multivariate regression analysis of meteorological parameters with TSP concentrations indicates that temperature, wind speed, and frequency of rainfall are potential predictors of TSP concentrations, where the respective p values for the model are p = 0.005, p = 0.049, and p = 0.046. The strong correlation between usual co-pollutants, CO, NO₂, and NO_X with TSP concentrations, as indicated by the Pearson correlation values of 0.87, 0.86, and 0.77, respectively, implies substantial pollution from mobile sources. The weak correlation of SO₂ with TSP concentrations rules out a significant pollution contribution from power plants. The speciation of TSPs in winter showed the percentage proportions of water-soluble ions, metal elements, and carbon content in winter as 60%, 15%, and 25%, while in summer, they were 68%, 14%, and 18%, respectively. Water-soluble ions were the most significant composition for both seasons, where the predominant species in summer and winter are SO₄²⁻ and NO₃⁻, respectively. In the TSP metal elements profile, the proportion of natural origin ones exceeded those from anthropogenic sources. The health risk assessment indicates a significant cancer risk posed by chromium, while that posed by other metal elements including Co, Ni, As, and Pb are insignificant. Additionally, all metal elements’ chronic daily occupational exposure levels were below the reference doses except for Cu and Zn. Insights from this investigation can inform decisions on the design of the TSP-capturing mechanism. Specifically, water sprays to capture the water-soluble portion would substantially reduce the amplified concentrations of TSPs, especially in winter. Full article

Anthropogenic nitrogen deposition has the potential to change the leaf water-use strategy in the subtropical region of China. Nevertheless, the whole-tree level response crucial for the ecosystem functions has not been well addressed over the past decades. In this study, the stem sap flux density (J_S) was monitored for the whole-tree water transport capacity in two dominant species (Schima superba and Castanopsis chinensis) in a subtropical forest. To simulate the increased nitrogen deposition, the NH₄NO₃ solutions were sprayed onto the forest canopy at 25 kg ha⁻¹ year⁻¹ (CAN25) and 50 kg ha⁻¹ year⁻¹ (CAN50), respectively, since April 2013. The J_S and microclimate (monitored since January 2014) derived from the whole-tree level stomatal conductance (G_S) were used to quantify the stomatal behavior (G_S sensitive to vapor pressure deficit, G_S-VPD) in response to the added nitrogen. The maximum shoot hydraulic conductance (K_shoot-max) was also measured for both species. After one-year of monitoring in January 2015, the mid-day (J_S-mid) and daily mean (J_S-mean) sap flux rates did not change under all the nitrogen addition treatments (p > 0.05). A consistent decline in the G_S-VPD indicated an enhanced isohydric behavior for both species. In addition, the G_S-VPD in the wet season was much lower than that in the dry season. S. superba had a lower G_S-VPD and decreased J_S-mid/J_S-mean, implying a stronger stomatal control under the fertilization, which might be attributed to the low efficient diffuse-porous conduits and a higher J_S. In addition, the G_S for S. superba decreased and the G_S-VPD increased more under CAN50 than that under CAN25, indicating that the high nitrogen dose restrains the extra nitrogen benefits. Our results indicated that the J_S for both species was decoupled from the leaf transpiration for both species due to an enhanced isohydric behavior, and a xylem anatomy difference and fertilization dose would affect the extent of this decoupling relation. Full article

Urban air pollution is rapidly becoming a major environmental problem of public concern in several developing countries of the world. Jeddah, the second-largest city in Saudi Arabia, is subject to high air pollution that has severe implications for the health of the exposed population. Fine particulate matter (PM_2.5) samples were collected for 24 h daily, during a 1-year campaign from 2013 to 2014. This study presents a detailed investigation of PM_2.5 mass, chemical composition, and sources covering all four seasons of the year. Samples were analyzed for black carbon (BC), trace elements (TEs), and water-soluble ionic species (IS). The chemical compositions were statistically examined, and the temporal and seasonal patterns were characterized using descriptive analysis, correlation matrices, and elemental enrichment factor (EF). Source apportionment and source locations were performed on PM_2.5 samples using the positive matrix factorization (PMF) model, elemental enrichment factor, and air-mass back trajectory analysis. The 24-h mean PM_2.5 and BC concentrations ranged from 33.9 ± 9.1–58.8 ± 25 µg/m³ and 1.8 ± 0.4–2.4 ± 0.6 µg/m³, respectively. Atmospheric PM_2.5 concentrations were well above the 24-h WHO guideline of 15 µg/m³, with overall results showing significant temporal and seasonal variability. EF defined two broad categories of TEs: anthropogenic (Ni, V, Cu, Zn, Cl, Pb, S, Lu, and Br), and earth-crust derived (Al, Si, Mg, K, Ca, Ti, Cr, Mn, Fe, and Sr). The five identified factors resulting from PMF were (1) fossil-fuels/oil combustion (45.3%), (2) vehicular emissions (19.1%), (3) soil/dust resuspension (15.6%), (4) industrial mixed dust (13.5%), and (5) sea-spray (6.5%). This study highlights the importance of focusing control strategies, not only on reducing PM concentration but also on the reduction of components of the PM as well, to effectively protect human health and the environment. Full article

Spraying roads with water on a large scale in Chinese cities is one of the supplementary precaution or mitigation actions implemented to control severe air pollution events or heavy haze-fog events in which the mechanisms causing them are not yet fully understood. These air pollution events were usually characterized by higher air humidity. Therefore, there may be a link between this action and air pollution. In the present study, the impact of water spraying on the PM_2.5 concentration and humidity in air was assessed by measuring chemical composition of the water, undertaking a simulated water spraying experiment, measuring residues and analyzing relevant data. We discovered that spraying large quantities of tap or river water on the roads leads to increased PM_2.5 concentration and humidity, and that daily continuous spraying produces a cumulative effect on air pollution. Spraying the same amount of water produces greater increases in humidity and PM_2.5 concentration during cool autumn and winter than during hot summer. Our results demonstrate that spraying roads with water increases, rather than decreases, the concentration of PM_2.5 and thus is a new source of anthropogenic aerosol and air pollution. The higher vapor content and resultant humidity most likely create unfavorable meteorological conditions for the dispersion of air pollution in autumn and winter with low temperature. Full article