Potential Human Health Risks Research Articles

Origin and Effects of Microplastics on Soil Health, Microbial Community and Plants

Microplastics are a growing threat to entire ecosystems, their presence in soil and water ecosystems has received a lot of attention lately. The detection, occurrence, characterization, and toxicology of microplastics in freshwater and marine ecosystems have been the subject of recent research; yet, compared to aquatic environments, our knowledge of the ecological impacts of microplastics in soil ecosystems is relatively restricted. To address the potential ecological and human health risks caused by microplastics in soil, we have compiled literature here that studies the sources, migration of microplastics in soil, negative impacts on soil health and function, trophic transfer in food chains, and the corresponding adverse effects on soil organisms. This paper aims to fill in information gaps, clarify the ecological impacts of microplastic pollution in soil, and suggest future research directions related to microplastic pollution and the ensuing soil ecotoxicity. To lessen the dangers associated with microplastic contamination, this review also focuses on controlling the amount of microplastics in soil and developing management and remediation strategies.

Hydrochemical characterization of a Dinaric karst catchment in relation to emerging organic contaminants

The main findings of a hydrochemical investigation conducted within a typical Dinaric karst catchment located in Southern Croatia are outlined. The studied aquifer is drained by the Jadro and Žrnovnica springs, which are important for the regional and local water supplies, respectively. Presumably, there is intercatchment groundwater flow coming from the neighbouring Cetina River catchment. Various factors governing aquifer hydrochemistry and their interplay with emerging organic contaminants (EOCs) that were detected at different water resources in ng/L concentrations was assessed. A total of 26 sampling campaigns (October 2019 – October 2022) were conducted at two springs, in a river and at a deep borehole, all representative of this complex hydrogeological system. Assessment of major ion constituents and saturation indices calculated with PHREEQC revealed the sampled water resources are of a Ca-HCO3 type due to the predominant weathering of the carbonate mineral calcite. Sharp spikes observed in chemographs indicated a highly karstified system with an effective conduit network allowing rapid spring responses to precipitation events. Water resources are of good chemical status, as affirmed by anthropogenic contamination indicators, with nitrates, chlorides and sulphates all below maximum threshold values. Strong positive correlations were found between EOCs concentration, number of detected compounds, and nitrates in the Cetina River, indicating a common origin, most likely wastewater. Identification of persistent EOCs including widely used repellent N,N-diethyl- metatoluamide (DEET) during base flow conditions and its strong positive correlation with the Ca2+ content in both the Cetina and Jadro samples, suggests potential storage in the epikarst and aquifer matrix. This coupling of conventional hydrochemical indicators and novel markers of anthropogenic impacts, including EOCs, in vulnerable karst water resources is a crucial advancement in the assessment and management of emerging environmental and potential human health risks. Such an approach is pivotal for the sustainable protection of hydrogeologically intricate sites.

Formation of nanoparticles during accelerated UV degradation of fleece polyester textiles

Micro- and nanoplastics have emerged as critical pollutants in various ecosystems, posing potential environmental and human health risks. Washing of polyester textiles has been identified as one of the sources of nanoplastics. However, other stages of the textile life cycle may also release nanoparticles. This study aimed to examine nanoparticle release during UV degradation of polyester textiles under controlled and real-world conditions. Fleece polyester textiles were weathered under simulated sunlight for up to two months, either in air or submerged in water. We conducted bi-weekly SEM image analyses and quantified released nanoparticles using nanoparticle tracking analysis (NTA). At week 0, the fiber surface appeared smooth after prewashing. In the air group, nanoparticles appeared on the fiber surface after UV-exposure. In the group of textiles submerged in water, the surfaces developed more pits over time. The cumulative nanoparticle emission from the weathered textiles ranged from 1.4 × 1011 to 4.0 × 1011 particles per gram of fabric in the air group and from 1.6 × 1011 to 4.4 × 1011 particles per gram of fabric in the water group over two months. The predominant particle size fell into the 100 to 200 nm range. The estimated mass of the released nanoparticles was 0.06–0.26 g per gram of fabric, which is lower than the amount released during the washing of new textiles. Additionally, Scanning Transmission X-ray Microscopy (STXM) images indicated that the weathered nanoparticles underwent oxidation. Overall, the research offers valuable insights into nanoparticle formation and release from polyester textiles during UV degradation.

Bioaccumulation of trace metals in edible terrestrial snails, Theba pisana and Otala spp., in a dumpsite area in Morocco and assessment of human health risks for consumers.

This study assessed the bioaccumulation patterns of five trace metals (Cd, Cr, Co, Cu, and Zn) in two edible snail species, Theba pisana and Otala spp., collected from a dumpsite in Safi City, Morocco. The results indicated that bioaccumulation might be species-specific, as metal concentration profiles varied between the two snail species. Additionally, higher metal levels in the dumpsite snails confirmed their potential as bioindicators of trace metal pollution in terrestrial environments. However, the distribution of trace elements within the edible parts of the snails showed marked unevenness, with the viscera accumulating more metals than the foot. The study also evaluated the potential human health risks associated with consuming these snails. Trace metal levels in the edible parts exceeded most international safety thresholds. The estimated daily intakes (EDIs) of trace metals through snail consumption were below the provisional tolerable daily intakes (PTDIs) for both children and adults, suggesting that daily consumption is generally safe. Nonetheless, the hazard index (HI) indicated that children might face health risks from long-term consumption of contaminated snails (HI > 1), while adults are less likely to experience such complications (HI < 1). The total target carcinogenic risk (TTCR) was below 1E-04 for both children and adults, indicating negligible to acceptable carcinogenic risks for all consumer groups.

The role of HMGB1 on SiC NPs-induced inflammation response in lung epithelial-macrophage co-culture system

In recent years, carbonized silicon nanoparticles (SiC NPs) have found widespread scientific and engineering applications, raising concerns about potential human health risks. SiC NPs may induce pulmonary damage through sustained inflammatory responses and oxidative stress, with unclear toxicity mechanisms. This study uses an in vitro co-culture model of alveolar macrophages (NR8383) and alveolar epithelial cells (RLE-6TN) to simulate the interaction between airway epithelial cells and immune cells, providing initial insights into SiC NP-triggered inflammatory responses. The research reveals that increasing SiC NP exposure prompts NR8383 cells to release high mobility group box 1 protein (HMGB1), which migrates into RLE-6TN cells and activates the receptor for advanced glycation end-products (RAGE) and Toll-like receptor 4 (TLR4). RAGE and TLR4 synergistically activate the MyD88/NF-κB inflammatory pathway, ultimately inducing inflammatory responses and oxidative stress in RLE-6TN cells, characterized by excessive ROS generation and altered cytokine levels. Pretreatment with RAGE and TLR4 inhibitors attenuates SiC-induced HMGB1 expression and downstream pathway proteins, reducing inflammatory responses and oxidative damage. This highlights the pivotal role of RAGE-TLR4 crosstalk in SiC NP-induced pulmonary inflammation, providing insights into SiC NP cytotoxicity and nanomaterial safety guidelines.

Potential Human Health Risk from Toxic/Carcinogenic Arsenic in Ripe and Unripe Tomatoes Grown in Wastewater Exposed Zone

Potential Human Health Risk from Toxic/Carcinogenic Arsenic in Ripe and Unripe Tomatoes Grown in Wastewater Exposed Zone

Effects of Freeze-Thaw Cycles on Bioaccessibilities of Polycyclic Aromatic Hydrocarbons.

The bioaccessibility of particle-bound hydrophobic organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), and the factors influencing their re-release are crucial for assessing potential human health risks via inhalation and hand-mouth exposure. However, the mechanisms by which various factors affect the re-release of PAHs in body fluids, particularly in response to environmental changes like freeze-thaw cycles, remain unclear. To obtain a better understanding, an in vitro method was employed to investigate the re-release processes of PAHs from different soil types (ferrallitic soil and calcareous soil) in simulated body fluids (simulated lung fluid and simulated saliva) under varying freeze-thaw conditions (0, 15, and 30 cycles). The findings indicated that the bioaccessibilities of phenanthrene and pyrene decreased with the frequency of freeze-thaw cycles, which were constrained by soil nature and simulated body fluids compositions as well. Additionally, this study observed that the portion of reversible adsorption of PAHs declined after exposure to freeze-thaw cycles in a nonlinear manner, suggesting that the potential human health risk associated with PAHs could be mitigated due to the "aging effect" which occurred as PAHs became less bioaccessible over time. These results underscore the importance of considering the characteristics of pollutants, body fluids, and environmental media when conducting a precise assessment of the human health risks posed by such contaminants.

Lethal and behavioral effects of semi-purified microcystins, Micropeptin and apolar compounds from cyanobacteria on freshwater microcrustacean Thamnocephalus platyurus

The mass proliferation of cyanobacteria, episodes known as blooms, is a concern worldwide. One of the most critical aspects during these blooms is the production of toxic secondary metabolites that are not limited to the four cyanotoxins recognized by the World Health Organization. These metabolites comprise a wide range of structurally diverse compounds that possess bioactive functions. Potential human and ecosystem health risks posed by these metabolites and co-produced mixtures remain largely unknown. We studied acute lethal and sublethal effects measured as impaired mobility on the freshwater microcrustaceans Thamnocephalus platyurus for metabolite mixtures from two cyanobacterial strains, a microcystin (MC) producer and a non-MC producer. Both cyanobacterial extracts, from the MC-producer and non-MC-producer, caused acute toxicity with LC50 (24 h) values of 0.50 and 2.55 mgdw_biomass/mL, respectively, and decreased locomotor activity. Evaluating the contribution of different cyanopeptides revealed that the Micropeptin-K139-dominated fraction from the MC-producer extract contributed significantly to mortality and locomotor impairment of the microcrustaceans, with potential mixture effect with other cyanopeptolins present in this fraction. In the non-MC-producer extract, compounds present in the apolar fraction contributed mainly to mortality, locomotor impairment, and morphological changes in the antennae of the microcrustacean. No lethal or sublethal effects were observed in the fractions dominated by other cyanopetides (Cyanopeptolin 959, Nostoginin BN741). Our findings contribute to the growing body of research indicating that cyanobacterial metabolites beyond traditional cyanotoxins cause detrimental effects. This underscores the importance of toxicological assessments of such compounds, also at sublethal levels.

Solar-powered detection of organic dyes using nitrogen-doped N-TiO2/Ag2O nanorod arrays.

Organic pollutant detection has caused widespread concern regarding due to their potential environmental and human health risks. In this work, a nitrogen-doped titanium dioxide/silver oxide (N-TiO2/Ag2O) composite has been designed asa sensitive photoelectrochemical (PEC) monitoring platform of organic dyes. Sensitive determination relies on the outstanding PEC performance of N-TiO2/Ag2O. The improved PEC performance stems from the effective separation of photocarriers and the extended light response range provided by the narrowing bandgap and a p-n junction with N-TiO2/Ag2O. The N-TiO2/Ag2O electrode exhibits a photocurrent density of up to 2.2mA/cm2, demonstrating three times increase compared withthe photocurrent density observed with the pure TiO2 film. The linear detection range for rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) is 0.2ng/mL to 10 μg/mL with an ultrasensitive detection limit of 0.2ng/mL without bias voltage. Due to the outstanding photocurrent density and sensitive response to organic pollutants, the N-TiO2/Ag2O PEC sensor provided a promising analytical method to detect environmental organic dyes.

A field trial for remediation of multi-metal contaminated soils using the combination of fly ash stabilization and Zanthoxylumbungeanum- Lolium perenne intercropping system

Insitu stabilization and phytoextraction are considered as two convenient and effective technologies for the remediation of toxic elements (TEs) in soils. However, the effectiveness of these two remediation technologies together on the bioavailability and phytoextraction of TEs in field trials has not been explored yet. Specifically, the remediation potential of fly ash (FA; as stabilizing agent) and ryegrass (as a TE accumulator) intercropped with a target crop for soil polluted with multiple TEs has not been investigated yet, particularly in long-term field trials. Therefore, in this study, a six-month combined remediation field experiment of FA stabilization and/or ryegrass intercropping (IR) was carried out on the farmland soils contaminated with As, Cd, Cr, Cu, Hg, Ni, Pb and Zn where Zanthoxylumbungeanum (ZB) trees as native crops were grown for years. The treatments include soil cultivated alone with ZB untreated- (control) and treated-with FA (FA), produced by burning lignite in Shaanxi Datong power plant, China, soil cultivated with ZB and ryegrass untreated- (IR) and treated-with FA (FA + IR). This was underpinned by a large-scale survey in Daiziying (China), which showed that the topsoils were polluted by Cd, Cu, Hg and Pb, and that Hg and Pb contents in the Zanthoxylumbungeanum fruits exceeded their allowable limits. The TEs contents in the studied FA were lower than their total element contents in the soil. The DTPA-extractable TEs contents of the remediation modes were as follows: FA < FA + IR < IR < control. Notably, TEs contents in the ZB fruits were lowest under the FA + IR treatment, which were decreased by 27.6% for As, 42.3% for Cd, 16.7% for Cr, 30.5% for Cu, 23.1% for Hg, 15.5% for Ni, 33.2% for Pb and 38.1% for Zn compared with the control treatment. Whereas the FA + IR treatment enhanced TEs contents in ryegrass shoots and roots, and the TEs contents in ryegrass shoots were below their regulatory limits for fodder crops. The findings confirmed that the combined remediation strategy, i.e., FA (with low content of TEs) stabilization effect and intercropping of ZB (target crop) and ryegrass (accumulating plant) could provide a prospective approach to produce target plants within safe TEs thresholds with greater economic benefits, while remediating soils polluted with multiple TEs and mitigating the potential ecological and human health risk. Those results are of great applicable concern.

Bioaccumulation of heavy metals in Capoeta tinca fish and health risk assessment

The This study evaluates the potential human health risks associated with five heavy metals (Zn, Pb, Cu, Cd, and Cr) in Capoeta tinca fish. It assesses the heavy metal burden in the muscle, gill, and liver tissues of C. tinca, and estimates the potential health risks for consumers by employing estimated daily intake (EDI) and standard hazard ratios (THQ) related to heavy metal consumption. Fish and water samples were taken from three different Regions as Sincan Brook (Sivas–Hafik), Habeş Brook (Sivas–Zara), and Tozanlı Brook (Sivas–Hafik), Turkey. The heavy metal concentrations in the brook water were found to be higher than the established safe for safety threshold in all the sampling points. Besides that, the values were observed to be lower than the allowed limits. Considering the fish tissues, the Pb, Cd, and Cr concentrations were found to be higher than the safe limits predicted by WHO. The findings indicate that the liver of C. tinca fish exhibited the highest accumulation of heavy metals across all sampling areas. The highest heavy metal concentrations found in fish muscles were found to be (Cu) 2.51 ± 0.91 μg·g-1, (Cr) 0.45 ± 0.03 μg·g-1, (Cd) 0.88 ± 0.04 μg·g-1, (Pb) 2.04 ± 0.03 μg·g-1, and (Zn) 13.12 ± 1.08 μg·g-1. The descending order of heavy metal accumulation in gills was found to be Zn &gt; Cu &gt;Pb &gt; Cd &gt; Cr. Moreover, for each heavy metal, the Bio–concentration factor (BCF) index, Acceptable Daily Intake, EDI, and THQ (&lt;1) values were found to be lower than the limits set in the international standards, indicating that no elements posing a threat to public health were encountered, thus not posing a short–term risk.

The effect of different types of microplastic and acute cadmium exposure on the Mytilus galloprovincialis (Lamarck, 1819)

Microplastic (MP) pollution is a pressing issue for both environmental health and the safety of human food sources. This study provides a comprehensive analysis of the effects of MPs on Mediterranean mussels (Mytilus galloprovincialis, Lamarck 1819), focusing on the food safety risks associated with MP and cadmium (Cd) exposure in these organisms intended for consumption. The retention of different polymer types of MPs in mussels was specifically evaluated, and the influence of Cd on MP retention across these polymers was investigated. Mussels were exposed to polystyrene (PS), polypropylene (PP), and polyethylene terephthalate (PET) MPs individually and in combination with the toxic metal Cd for a duration of 7 days. Antioxidant enzymes, oxidative stress parameters, and digestive system enzyme activities, selected as biomarkers for Cd and MPs pollution, were assessed. Furthermore, human consumption risk evaluations and limits regarding mussel intake were analysed in terms of food safety. The results suggest that exposure to Cd, MPs, or their combination induces oxidative stress, tissue damage, and neurotoxicity. Alterations in digestive enzyme activities could impact the mussels' energy acquisition from food and their capacity to conserve energy reserves. The estimated daily intake (EDI), provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), and target cancer risk (TCR) levels for all groups surpassed established limits, implying a significant health risk for humans consuming these products. These results underscore the potential health risks for humans associated with consuming mussels exposed to Cd and/or MPs and provide valuable data for monitoring pollution levels and ecological risks in aquatic organisms. Additionally, our findings reveal that the retention of Cd in mussel tissues varies significantly after exposure, with combinations of PET and Cd showing lower levels of Cd accumulation compared to other groups, suggesting a differential interaction that influences Cd retention.

Microplastics: Omnipresent and an ongoing challenge for medical science.

Micro- and nanoplastics are omnipresent not only in the environment, but have also been detected in human body fluids and tissue. The subsequent commentary provides a perspective about potential risks for human health as well as resulting challenges for medical science.

Prevalence of opportunistic pathogens and anti-microbial resistance in urban aquaculture ponds

Bacterial antimicrobial resistance (AMR) has emerged as a significant concern worldwide. The microbial community profile and potential AMR level in aquaculture ponds are often undervalued and attract less attention than other aquatic environments. We used amplicon and metagenomic shotgun sequencing to study microbial communities and AMR in six freshwater polyculture ponds in rural and urban areas of Bangladesh. Amplicon sequencing revealed different community structures between rural and urban ponds, with urban ponds having a higher bacterial diversity and opportunistic pathogens including Streptococcus, Staphylococcus, and Corynebacterium. Despite proteobacterial dominance, Firmicutes was the most interactive in the community network, especially in the urban ponds. Metagenomes showed that drug resistance was the most common type of AMR found, while metal resistance was only observed in urban ponds. AMR and metal resistance genes were found mainly in beta and gamma-proteobacteria in urban ponds, while AMR was found primarily in alpha-proteobacteria in rural ponds. We identified potential pathogens with a high profile of AMR and metal resistance in urban aquaculture ponds. As these ponds provide a significant source of protein for humans, our results raise significant concerns for the environmental sustainability of this food source and the dissemination of AMR into the food chain.

Bioaccumulation of Lead and Mercury in Water, Sediment, and Fish Samples of Baraila Lake, Vaishali, Bihar.

In the current study, a protected subtropical wetland in Bihar (India), Baraila Lake, was investigated for heavy metal (Pb and Hg) status. These metals tend to bioaccumulate in fish, posing a concern to human health. This study reported the concentration of lead and mercury in water, sediment, and fish muscles of Baraila Lake in the year 2022. The samples were collected from pre-monsoon and post-monsoon seasons at four sampling locations, i.e., Loma, Dhulwar, Chakaiya, and Kawai Baraila, and were analyzed in triplicates. Lead concentration in water samples of all four sites of Baraila Lake observed during pre-monsoon and post-monsoon season exceeded the permissible limit for drinking water, while the mercury concentration of all sites was under the permissible limit in both seasons as prescribed by WHO. The extent of elemental pollution was evaluated using the Geo-accumulation index (Igeo), contamination factor (CF), contamination degree (Cd), ecological risk factor (Er), and the potential ecological risk index (Ri). Lead concentration in fish muscles of both seasons exceeded the permissible limit, while the concentration of mercury exceeded in Xenentodon cancila (0.55 ± 0.07µg/g) during the pre-monsoon season. Also, estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) were calculated in different fish muscles to assess potential human health risks. A higher THQ value of 1.303 was observed in carnivore fish during the pre-monsoon season.

Potential ecological and human health risk assessments of soil heavy metals in orchards of Antalya province in Türkiye

ABSTRACT Agricultural inputs containing heavy metals are used intensively in Türkiye. However, studies on the assessment of the effects of heavy metals on the environmental and human health risks of agricultural areas in Türkiye are very limited. The aim of this study was to determine the concentrations, sources and potential ecological and human health risks of heavy metals in soils from orchards in Antalya, Türkiye. A total of 127 soil samples were collected and analysed for cadmium (Cd), lead (Pb), nickel (Ni), chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn). The mean concentrations of total Cd, Pb, Ni, Cr, Co, Fe, Mn, Cu and Zn were found to be 4.54, 64.68, 145.80, 94.00, 23.92, 28264, 763.30, 44.91, and 63.67 mg kg−1, respectively. The mean concentrations of Cd, Co, Ni, Pb, Cu and Mn of soils were higher than the European soil mean values. Enrichment factor (EF) and contamination factor (CF) values of soils indicate serious enrichment for Cd, Pb and Ni. According to the principal component analysis, Cd concentration in the soil from was anthropogenic sources, Ni, Cr and Pb from both anthropogenic and lithogenic origin while other heavy metals from natural sources. Total hazard index (THI) values of heavy metals were <1, suggesting that there were currently absent non-carcinogenic health risks to residents through ingestion, inhalation and dermal contact. Hazard index (HI) indicated that children (3.75) were sensitive 9.4 times more than adults (0.40) to non-carcinogenic risks of heavy metals. The carcinogenic risk values of Cd, Cr, Co and Ni were acceptable range and not expected carcinogenic risks.

Dissemination of antimicrobial resistance in agricultural ecosystems following irrigation with treated municipal wastewater

The spread of antimicrobial resistance (AMR) in agricultural systems via irrigation water is a serious public health issue as it can be transmitted to humans through the food chain. Therefore, understanding the dissemination routes of antibiotic resistance genes (ARGs) in agricultural systems is crucial for the assessment of health risks associated with eating fresh vegetables such as spinach and radish irrigated with treated municipal wastewater (TMW). In this study, we investigated the bacterial community structure and resistome in the soil–plant–earthworm continuum after irrigation of spinach and radish with TMW containing the antibiotics trimethoprim (TMP), sulfamethoxazole (SMZ), and sulfapyridine (SPD) using 16S rRNA gene sequencing and high throughput quantitative PCR (HT-qPCR). The study was conducted in two phases: Phase I involved eight weeks of spinach and radish production using TMW for irrigation, whereas Phase II entailed three weeks of earthworm exposure to contaminated plant material obtained in Phase I. The 16S data indicated that the rhizosphere bacterial community composition and structure were more resilient to antibiotic residuals in the irrigated water, with radish showing less susceptibility than spinach than those of bulk soils. The HT-qPCR analysis revealed that a total of 271 ARGs (out of 285) and 9 mobile genetic elements (MGEs) (out of 10) were detected in all samples. Higher diversity and abundance of ARGs were observed for samples irrigated with higher concentrations of antibiotics in both spinach and radish treatments. However, compared to spinach, radish ARG dynamics in the soil biome were more stable due to the change of antibiotic introduction to the soil. At the class level, multi-drug resistance (MDR) class was altered significantly by the presence of antibiotics in irrigation water. Compared to earthworm fecal samples, their corresponding soil environments showed a higher number of detected ARGs, suggesting that earthworms could play a role in reducing ARG dissemination in the soil environments. These findings will not only provide insight into the dissemination of ARGs in agricultural environments due to antibiotic residuals in irrigated water but could help understand the potential human health risks associated with ARGs.

Tannic acid-assisted construction of amino-functionalized cellulose nanofiber composite aerogel for high-performance adsorption of Cr(VI), Cu(II) and Congo red: Experimental and DFT studies

With industrialization, heavy metals and dyes pose potential environmental and human health risks. Developing adsorbent materials with three-dimensional structures and abundant active sites is essential for removing these pollutants. In this study, we developed an environmentally friendly, high-adsorption composite aerogel (CNF-TA-PMMT-PEI) comprising cellulose nanofiber (CNF), polydopamine-modified montmorillonite (PMMT), tannic acid (TA), and polyethyleneimine (PEI). The introduction of TA and PEI increased the number of adsorbed active sites and the interaction between CNF and PMMT through strong hydrogen and chemical bonding. CNF-TA-PMMT-PEI has a honeycomb-like pore structure, high porosity (98.29 %), abundant functional groups, and showed rapid and excellent adsorption performance for Cr(VI), Cu(II), and Congo red (CR), with the Qm of 456.62, 289.86, and 3429.23 mg/g, respectively. The adsorption process followed the pseudo-second-order kinetic model and Langmuir model, indicating that the chemisorption of the monomolecular layer controlled the adsorption, and the thermodynamic adsorption indicated a spontaneous heat absorption reaction. The aerogel had good anti-interference properties and excellent adsorption performance in natural water. After 7 cycles, the removal of Cr(VI), Cu(II) and CR was maintained at 74.81 %, 68.23 % and 81.54 % of the initial performance, respectively. FTIR, XPS and DFT calculations revealed the amine group of the PEI and the phenolic hydroxyl group on TA are the main adsorption sites. The CR had the lowest adsorption energy (−4.23 Ha) compared to Cu(II) and Cr(VI), suggesting stronger interactions and greater stability on CNF-TA-PMMT-PEI. The adsorption mechanism for Cr(VI) involved electrostatic interactions, reduction, and chelation. For Cu(II), including chelation. For CR, adsorption through electrostatic attraction, π-π interactions, and Schiff base formation. In summary, CNF-TA-PMMT-PEI is an eco-friendly adsorbent with outstanding adsorption capacity and effective recovery performance for simulated wastewater.

Synthesis and Characterization of Environmentally Friendly β-Cyclodextrin Cross-Linked Cellulose/Poly(vinyl alcohol) Hydrogels for Adsorption of Malathion.

The widespread use of malathion enhances agricultural plant productivity by eliminating pests, weeds, and diseases, but it may lead to serious environmental pollution and potential health risks for humans and animals. To mitigate these issues, environmentally friendly hydrogel adsorbents for malathion were synthesized using biodegradable polymers, specifically cellulose, β-cyclodextrin (β-CD), poly(vinyl alcohol) (PVA), and biobased epichlorohydrin as a cross-linker. This study investigated the effects of the cellulose-to-PVA ratio and epichlorohydrin (ECH) content on the properties and malathion adsorption capabilities of β-CD/cellulose/PVA hydrogels. It was found that the gel content of the hydrogels increased with a higher cellulose-to PVA and ECH ratio, whereas the swelling ratio decreased, indicating a denser structure that impedes water permeation. In addition, various parameters affecting the malathion adsorption capacity of the hydrogel, namely, contact time, pH, hydrogel dosage, initial concentration of malathion, and temperature, were studied. The hydrogel prepared with a β-CD/cellulose/PVA ratio of 20:40:40 and 9 mL of ECH exhibited the highest malathion adsorption rate and capacity, which indicated an equilibrium adsorption capacity of 656.41 mg g-1 at an initial malathion concentration of 1000 mg L-1. Fourier transform infrared spectroscopy (FTIR), ζ-potential, and X-ray photoelectron spectroscopy (XPS) and NMR spectroscopy confirmed malathion adsorption within the hydrogel. The adsorption process followed intraparticle diffusion kinetics and corresponded to Freundlich isotherms, indicating multilayer adsorption on heterogeneous substrates within the adsorbent, facilitated by diffusion.

Cyanotoxins bioaccumulation by fish in an anthropized reservoir in central Mexico

The bioaccumulation of cyanotoxins has been well documented in exposed organisms including fish, which represent a potential route to cyanotoxins transfer to humans by consumption of contaminated food. We determined the bioaccumulation of neurotoxic saxitoxins and hepatotoxic microcystins in muscle and liver/viscera of native (Goodea atripinnis), introduced (Poeciliopsis gracilis), and commercially important (Oreochromis niloticus) fish in Santa Catarina, an anthropized reservoir in Central Mexico. Additionally, we calculated the potential risk of human exposure due to the consumption of the studied species. The Santa Catarina Reservoir showed some physical and chemical water parameters generally associated with cyanobacterial blooms (e.g., high phycocyanin, chlorophyll-a, dissolved phosphorus concentrations, and alkaline pH) with presence of cyanotoxins produced by the cyanobacteria genera Microcystis, Dolichospermum, and Planktothrix, which were found in dissolved and particulate (sestonic) fractions of water. Moreover, we detected the presence of saxitoxins and microcystins in the tissues of all species studied. The risk of intoxication for humans was lower for the consumption of Nile tilapia muscle than for the other analyzed species, whose consumption should be avoided since it exceeds the recommended daily intake of microcystins for a short-term (i.e., two-week exposure time). These findings are remarkable because commercial fishing in reservoirs and the consumption of these fish could represent a route to human exposure to toxins, particularly microcystins. Our results highlight the need for the detection of cyanotoxins and the evaluation of their bioaccumulation by fish in unstudied eutrophic waterbodies, to reduce the potential health risk for humans and the environment.