Emerging Contaminants最新文献

Blast furnace slag (BFS) is a secondary material generated during the process of producing iron in blast furnaces, prompting scholars to concentrate on its efficient management and broad application for the creation of valuable commodities. This study examines the mineral composition, adsorption characteristics, and utilization of BFS and its silica counterparts. Recent developments in the application of BFS and its functionalized materials for pollution mitigation are examined, specifically concentrating on the elimination of nitrogen, phosphorus, metal ions, pharmaceutical effluents, waste oils, and dye molecules from wastewater. Moreover, these inexpensive adsorbents exhibit significant specific surface areas, possess microporous configurations, and contain alkaline components like calcium oxide, magnesium oxide, and aluminum oxide. This review further elucidates the present state of BFS-based adsorbents in the absorption of acid gases, with a specific focus on CO₂. The problems associated with widespread BFS usage are analyzed, and potential solutions for effective resource utilization are discussed.

The ESKAPE pathogens and E. coli are of significant public health concern and are listed among the top priorities of the World Health Organization. These pathogens are equally important for animal and public health, but their interaction with animal, human, and environmental aspects needs to be sufficiently studied. We investigated the comprehensive molecular characterization of three ESKAPE pathogens and E. coli recovered from milk, farm workers, and environmental settings in Hainan province. Minimum inhibitory concentration (MIC), extended-spectrum β-lactamase production, and biofilm production were performed per set standard protocols. The isolates were further processed by PCR and sequencing to detect resistome, virulome, and mobilome. The study found four Enterobacteriaceae species (E. coli, n=32; K. pneumoniae, n=13; E. cloacae, n=3; E. aerogenes, n=1) among n=49 bacterial isolates from the study area. Most of the strains exhibited resistance against tetracycline (71.4%), ampicillin (61.2%), florfenicol (44.9%), and ciprofloxacin (42.9%), while none of the strains was resistant against meropenem and amikacin. The MDR and ESBL-production percentages were 55.1% and 34.7 %, respectively. The resistance determinants for β-lactams (bla_TEM, bla_OXA-2, bla_SHV, bla_CTX-M), aminoglycosides (aac(3ʹ)-IIa), quinolones (qnrB, qnrS), tetracyclines (tetA, tetD), florfenicol (floR), sulfonamides (sul1, sul2), trimethoprim (dfrA14), and MDR efflux pumps (oqxA, oqxB) were detected along with diverse plasmid replicon types and integrons (intl3, 55.1%; intl1, 18.4%). The detection of virulence determinants was noted at a higher rate, and most of the strains were identified as biofilm producers by genotype (85.7%). The current study findings revealed diversified resistance and virulence determinants along with mobilome in ESKAPE pathogens and E. coli, which may pose a significant threat to human health through the food chain and environmental exposure and need immediate attention.

Mercury pollution from a chlor-alkali plant has caused a long-term impact on the northwest of the Persian Gulf. In this article, the history of mercury concentration in Musa estuary, Iran, is summarized from previous research and reports and used to estimate the health risk assessment. Despite the closure of the chlor-alkali plant in 2016, the mercury level in sediments and biota is still higher than the acceptable standards in some parts of the estuary. Mercury concentrations and bioaccumulation in the food chain, including fish, crustaceans, birds, and humans, were evaluated. Health risk assessments indicate that consuming some fish species may put children and adults at risk of mercury exposure. Further study is required to fill the gaps for mercury monitoring and recovery.

The photochemistry of organic contaminants present in ice is receiving growing attention, given the wide presence of ice during winter in temperate regions as well as Polar and mountain environments. Differences between ice photochemistry and aqueous photochemistry, however, influence the quantitative fate and transformation of organic chemicals present in freshwater, marine and ice-cap environments and these differences need to be explored. Here we comparatively studied the ice and aqueous photochemistry of three antibiotics [levofloxacin (LVX), sulfamerazine (SM), and chlortetracycline (CTC)] under the same simulated sunlight (λ > 290 nm). Their photodegradation in ice/water followed pseudo-first-order kinetics, whereby the photolytic rates of LVX in ice and water were found to be similar, SM photodegraded faster in ice, while CTC underwent slower photodegradation in ice. Whether individual antibiotics underwent faster photodegradation in ice or not depends on the specific concentration effect and cage effect coexisting in the ice compartment. In most cases, the fastest photodegradation occurred in freshwater ice or in fresh water, and the slowest photolysis occurred in pure-water ice or in pure water. This can be attributed to the effects of key photochemical reactive constituents of Cl⁻, HA, NO₃⁻ and Fe(III), that exist in natural waters. These constituents at certain levels showed significant effects (P < 0.1) on the photolysis, not only in ice but also in water. However, these individual constituents at a given concentration, serve to either enhance or suppress the photoreaction, depending on the specific antibiotic and the matrix type (e.g., ice or aqueous solution). Furthermore, extrapolation of the laboratory findings to cold environments indicate that pharmaceuticals present in ice will have a different photofate compared to water. These results are of particular relevance for those regions that experience seasonal ice cover in fresh water and coastal marine systems.

Microplastics (MPs) (<5 mm) are a growing environmental problem and have garnered significant global interest from scientists and policy makers. Coastal ecosystems are vulnerable to MP pollution, and assessing their sources, fate, and transport in the environment is imperative for marine ecosystem health. Data for marine sediment are still limited, particularly in the Pearl River Estuary (PRE) ecosystem in China. Here, we assessed the abundance, characteristics, and risks of MPs in marine sediment from PRE. MPs abundance ranged from 2.05 × 10³ items ·kg⁻¹ to 7.75 × 10³ items ·kg⁻¹ (dry weight), and white and black MPs were the dominant colors. The majority (>64.12 %) of detected MPs were <0.85 mm and primarily consisted of pellets (36.84 %) and fragments (29.65 %). Three polymer types of MPs were identified by Fourier Transform Infrared Spectroscopy (FT-IR) including polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP). Polyurethane (PU) sponge was reported for the first time in this study area. Observations of the surface morphology of typical MPs using Scanning Electron Microscopy (SEM) showed that all MPs exhibited varying degrees of erosion, characterized by cracks, folds, and bumpy structures. Based on type and quantity of MPs and the polymers identified, we assessed and classified the risk of MP contamination in PRE sediment as category III, indicating severe ecosystem contamination. Our results may serve as an effective model for other estuaries facing similar pollution regimes and provides valuable information for marine sediment risk assessment.

Organochlorine pesticides are chlorinated hydrocarbon compounds. The production and use of organochlorine pesticides have been restricted around the world because they are persistent and toxic and able to undergo long-range transport and bioaccumulate. It is necessary to develop efficient techniques for eliminating organochlorine pesticides from environmental media, and we also need to better understand how these techniques operate. Understanding how organochlorine herbicides behave in various environmental settings is very crucial. We looked on the photodegradation of endosulfan (endosulfan I and II) and hexachlorobenzene (HCB), two common organochlorine insecticides. Tests were conducted with pesticides at different concentrations, dissolved in various organic solvents, and exposed to light at different wavelengths. Density Functional Theory (DFT) was employed to study solvent effects. Degradation kinetics followed first-order models. The pesticides dissolved in various organic solvents showed a decrease in their degradation rates in the following order: toluene > acetone > n-hexane. It was discovered that there was a good chance the Cl atoms on the benzene ring in HCB would be eliminated through nucleophilic processes. It was discovered that endosulfan breaks preferentially at the SO double bond. The findings will aid in the development of strategies for successfully eliminating organochlorine pesticides from environmental media by aiding in the prediction and assessment of the photochemical behaviors of the pesticides under various environmental circumstances.

The widespread presence of microplastics (MPs) in road dust has considerable concern regarding their potential risks to ecosystems and human health. Despite the massive production of plastic, the erudition of MPs distribution patterns in various sizes of deposited road dust is still limited around the globe. Thus, the aim of this research is to provide an unambiguous picture of MPs distributional pattern, identification, classification, quantification, and features from road dust in various zones and types of roadways in Dhaka, Bangladesh. This study examined MPs in road dust samples with particle sizes ranging from 300 to 150 μm (Group-A), 149-75 μm (Group-B), and <75 μm (Group-C). This work extracted MPs from road dust using 30 % H₂O₂, 1.6 g/cm³ ZnCl₂, and 0.45 μm filter paper. A fluorescent microscope (Motic B410E, Germany), Motic Pictures, and 3.0 ML software were utilized to identify MPs visually. Additionally, FTIR and SEM were utilized to determine the chemical composition of MPs. Group-A Road dust samples had a significantly higher concentration of MPs (38945 items/kg) compared to Group-B and <75 μm Group-C dust (16720 and 5945 items/kg, respectively). The distribution hierarchy for total MPs on average by location and type of road is as follows: paved road (355 items/5 g) > unpaved road (325 items/5 g) > soil samples (294 items/5 g), roadside dust samples (284 items/5 g), and mid-road (283 items/5 g). By taking into account all sizes of road dust samples, the MPs were classified as fiber (70.26 %), fragment (26.12 %), beads (0.66 %), films (1.32 %), and foams (1.58 %). It was found that adults inhaled MPs an average of 1612 items/day, while they ingested an average of 880 items/day. Children had an inhalation rate of 1232 items/day and an ingestion rate of 10267 items/day, which was 4–17 times greater than in other countries. This study identified 22 MPs polymer types, and SEM results show that MPs surfaces are being weathered into nanoplastics, creating a more hazardous environment.

Polyethylene microplastics (PE-MPs) have toxicity to ecological environment, including animals and plants. This study investigated the toxicity of photodegraded PE-MPs on Brassica rapa, which is a typical model plant and only have around a 30-day life cycle. It is noted that the presence of photodegraded PE-MPs inhibited Brassica rapa growth since the stem length decreased by 11.94%–51.11 % while the fresh weight and dry weight decreased by 18.56%–27.46 % and 1.90 %–6.91 % respectively, compared to the blank group. PE-MPs receiving more light radiation became more hydrophobic. This inhibited PE-MPs entering the plant body along with the process of plant absorbing water. Furthermore, when PE-MPs were located in the lower soil layers, Brassica rapa reaching them needs a longer time, hence showing lower toxicity effect than the case of PE-MPs located in the upper soil layer. The research outcomes also indicated that malondialdehyde (MDA) contents in photodegraded PE-MPs exposure group increased by 1.37%–7.28 % while the catalase activity (CAT) increased by 60.11 %. This means that PE-MPs caused oxidative stress response in plants, inducing plants to resist external stress. Transcriptomic analysis results showed that Brassica rapa, which was affected by PE-MPs, significantly up-regulated genes related to the plant-pathogen interaction pathway while the ribosome pathway genes were significantly down-regulated. This led to a decrease in growth rate and a decrease in the homeostatic level of the ribosomal subunit and hence resulting in abnormal leaf vein development. These conclusions indicated the toxic effect and damage mechanism of photodegraded PE-MPs on Brassica rapa. The novelty of this study was to use both univariate analysis and transcriptomic analysis to investigate how photodegraded PE-MPs exert toxicity on Brassica rapa. The results can provide a theoretical basis for revealing the influence of MPs on plant growth.

Novel brominated flame retardants (NBFRs) are a group of chemicals applied mainly as alternatives to the phased-out polybrominated diphenyl ethers (PBDEs). However, toxicological studies show that NBFRs may pose health risks similar to PBDEs.The present study reviews available information on the biomonitoring of NBFRs and their metabolites in humans through invasive and non-invasive biomarkers, as well as the toxicological effects of these chemicals both in vivo and in vitro. In general, higher concentrations of NBFRs were reported in tissues of occupationally exposed adults from NBFR production facilities, e-waste recycling facilities and inhabitants living close to these areas, compared to the general population. It is worth noting that NBFR human biomonitoring data are limited to few countries located in North America, Europe and Asia, while data from developing countries are scarce. Evidence from in vivo and in vitro toxicity studies show that several NBFRs can cause adverse health effects through various modes of action, mainly: hormone disruption, genotoxicity, endocrine disruption, and behavioural changes. Although few studies have investigated the biotransformation of NBFRs in humans, evidence suggests that the toxicity of some NBFRs may be augmented through their metabolites, as in the case of 2,3,4,5- tetrabromobenzoic acid (TBBA), which may exhibit higher toxicity than its parent compound 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB). More research is required to assess toxicity thresholds, toxic endpoints, and tolerable intakes for various NBFRs, and their metabolites in human. Comprehensive epidemiological studies are highly recommended to further understand the risk arising from human exposure to different NBFRs, particularly in occupational settings.

Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological importance. Here, we perform a study of water samples collected from 13 locations distributed across Botswana to obtain the first overview of the nature and distribution of chemical contaminants across the country's aquatic environment. High resolution mass spectrometry was applied using non-targeted and suspect screening methods to qualitatively analyse samples. A total of 114 contaminants of emerging concern (CECs) were identified including 68 (59.6 %) pharmaceuticals and pharmaceutical metabolites; 16 (14.2 %) pesticides; 13 (11.4 %) psychoactive compounds and metabolites; 11 (9.7 %) industrial chemicals and intermediates and lastly, 5 (4.4 %) personal care products. Allopurinol, 3,4-dimethylmethcathinone, and diazolidinyl urea represented the most commonly detected pharmaceutical, psychoactive drug and personal care product, respectively. The pesticide dodemorph and three industrial chemicals (stearamide, pthalic acid and bis(2-ethylhexyl) phthalate) were detected in all samples obtained. 90 CECs were detected in receiving water (from 7 sample locations), 75 in wastewater (from 3 sample locations) and 60 in surface water (from 9 sample locations). Of the compounds detected, only 8 had been identified in environmental samples acquired in Botswana previously. We discuss the variations in the nature and frequency of chemical pollutants detected in this work in a geographical context. The results indicate that Botswana's aquatic systems are subject to pollution, despite wastewater treatment and that in order to mitigate potentially harmful effects on both human and aquatic ecosystems, more investigations are required to correctly identify, track and tackle the sources of pollution.