Bivalve molluscs can acquire marine biotoxins by filter-feeding upon certain toxin-producing microalgae. The two most common syndromes observed in temperate coastal waters have been diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP). While DSP is a non-fatal gastrointestinal syndrome, PSP is a neurological syndrome which can lead to death by respiratory paralysis in high intoxication scenarios. In Portugal, the presence of both DSP and PSP toxins leads to recurrent seasonal bans of bivalve harvesting. On a few occasions, the bans were not placed in time, not properly disseminated to the public or were disregarded by recreational harvesters. Several cases of poisonings have been studied in collaboration between health authorities and the laboratory in charge of the biotoxin monitoring programme. Some of the outbreaks have even called the attention of the local media. In several of these recorded cases, a common trait has emerged throughout the years: bivalve harvest had often been done during very low tides attributed to either new or full moons. These tides expose intertidal bivalves more widely, increase harvesting time, and allow picking of larger-sized specimens. In some occasions, the consumers were extremely unfortunate because a noxious coincidence had occurred: larger-sized specimens were available but had attained the highest toxin content of the toxic season. This review alerts that despite costly monitoring programmes have been perfected through the years, human poisonings still take place due to the rapid increase in toxin levels and/or disrespect of harvest bans.

The soil microbiome comprises one of the most important and complex components of all terrestrial ecosystems as it harbors millions of microbes including bacteria, fungi, archaea, viruses, and protozoa. Together, these microbes and environmental factors contribute to shaping the soil microbiome, both spatially and temporally. Recent advances in genomic and metagenomic analyses have enabled a more comprehensive elucidation of the soil microbiome. However, most studies have described major modulators such as fungi and bacteria while overlooking other soil microbes. This review encompasses all known microbes that may exist in a particular soil microbiome by describing their occurrence, abundance, diversity, distribution, communication, and functions. Finally, we examined the role of several abiotic factors involved in the shaping of the soil microbiome.

Black carbon (BC) is a major light-absorbing component in the atmosphere and plays an important role in aerosol radiative forcing. In this study, the combination of monitoring data and the WRF-Chem model was used to study the source apportionment of BC in China during January 2017. Meanwhile, the aerosol-radiation interaction (ARI) effect of BC was also simulated. We found that the average BC/PM₂.₅ ratios were 4.8%, 4.2%, and 3.8% in Shijiazhuang, Tangshan, and Beijing, respectively. The source apportionment suggested that traffic emissions played a dominant role in the BC concentration over Beijing. The traffic, residential, industrial, and power contributions accounted for 41%, 32%, 25%, and 2% of total concentration, respectively. The BC concentration in Beijing was also affected by regional transport. During January, the contributions of monthly regional transport to BC and PM₂.₅ concentrations in Beijing were 41% and 49%, respectively. BC emissions decreased downward shortwave radiation (SWDOWN) at the surface, leading to a decrease in temperature. As a result, the planetary boundary layer height (PBLH) development was suppressed and the relative humidity increased. The stable meteorological conditions suppressed the dispersion of air pollutants and increased BC concentrations. Traffic emissions decreased the monthly SWDOWN by approximately 2.2 W/m², decreased 2 m temperature (T2) by approximately 0.1 °C, increased 2 m relative humidity (RH2) by approximately 0.5%, and decreased PBLH by approximately 4.4 m.

Zinc oxide nanoparticles are widely used in some domains (cosmetics, pharmaceuticals optical devices, and agricultural field) due to their physical, optical, and antimicrobial properties. However, the release of ZnO-NPs into the environment may affect organisms like fish with potential consequences for human health. Histological approaches of the acute effects of these materials on fish are scarce; thus, the present study aimed to investigate the potential toxic effects of acute exposure to ZnO particles in marine environments, by assessing histological changes in the gills, liver, spleen, and muscle of gilthead seabream (Sparus aurata) juveniles. Thus, fish were exposed for 96 h, via water, to 1 mg L⁻¹ of ionic zinc and zinc oxide particles (1.1, 1.2, and 1.4 μm of size). Histological examination revealed gills as the most affected organ, followed by liver, muscle, and spleen. In the gills, histopathological changes included hyperplasia of epithelial cells, fusion of the secondary lamellae, and lifting of the lamellar epithelium with edema. In the liver, lipid vacuolation of several degrees, necrosis of hepatic and pancreatic tissues, blood congestion in sinusoids and hepatoportal vessels, presence of cellular infiltrate, and melano-macrophages diffusion was found. Muscle showed degeneration, atrophy, thickening and necrosis of muscle fibers with edema between them, and presence of melano-macrophages in the muscle layer. Spleen was the less damaged organ, displaying congested blood, white pulp increase/rupture, and bigger and darker melano-macrophage aggregates in the splenic stroma. These results underline that the size of particles plays a determinant role in their potential pernicious effects. A short-term exposure caused major histopathological changes in relevant organs of S. aurata juveniles, possibly affecting their function.

This study focuses on utilizing a plant-derived urease enzyme (PDUE)–urea mixture to remove heavy metals from water as constituents of nano-carbonate minerals. The bio-removal process was conducted by individually mixing PbCl₂, CuCl₂, and NiCl₂ solutions with a PDUE–urea mixture, followed by incubation for 24 h at 23 ± 2 °C. The preliminary results revealed that the proposed method exhibited high Pb removal efficiency (˃ 99%) in a short time (8 h); meanwhile, moderate Cu and Ni removal efficiencies (67.91% and 58.49%, respectively) were obtained at the same incubation time. The concentration of heavy metals (50–200 mM) had an insignificant effect on the bio-removal rate, indicating that the PDUE–urea mixture is highly effective for the removal of heavy metals at different concentrations. The bio-removal process involved the transformation of soluble heavy metals into insoluble carbonate materials. A spherically shaped nano-cerussite (4–15 nm), a malachite hexahydrate nanosheet (thickness 8 nm), and an ultrafine micro-hellyerite (thickness 0.3 μm) were the main minerals produced by the Pb, Cu, and Ni bio-removal processes, respectively. As a beneficial application, nano-cerussite was used as an additive in an alkali-activated slag/ceramic waste-based geopolymeric coating. A preliminary study proved that increasing the nano-cerussite content enhanced the resistance of the geopolymeric coating to sulfur-oxidizing bacteria, which is detrimental to normal concrete, particularly in sewer systems.

A rare super-large fractured karst aquifer located in Zibo city, Shandong Province of Northern China was polluted by petroleum hydrocarbons from a petrochemical company. Over the last 30 years, it has been the focus of several remediation efforts. In this study, the contamination and natural attenuation characteristics of the petroleum hydrocarbons were elucidated using hydrogeochemical indicators (DO, DOC, Cl⁻, HCO₃⁻, pH, NO₃⁻, and SO₄²⁻), petroleum hydrocarbons elements and environmental isotopes (δ¹⁵NNO₃, δ¹⁸ONO₃, δ¹³CDIC, and δ¹³CDOC). With the aid of GIS, statistical analyses, as well as first-order decay model and electron-acceptor-limited kinetic model, the spatio-temporal evolution characteristics of the petroleum hydrocarbons were modeled. Results showed a positive natural attenuation trend over the last 3 decades where intrinsic biodegradation mechanism was found to be the most important factor driving the degradation of hydrocarbons in the aquifer system. The hydrogeochemical association between the indicators and petroleum hydrocarbons provided the evidences of biodegradation and also served as markers, highlighting the occurrence of anaerobic respiration without methanogenic activities within the heterogenous karst media. Furthermore, the mean natural attenuation rate of petroleum hydrocarbons was calculated to be 3.76 × 10⁻³/day whereby the current highest petroleum hydrocarbons concentration (361.13 μg/L) is estimated to be degraded completely in 6 years under the present hydrogeological and environmental conditions.

A combined approach based on multiple X-ray analytical techniques and conventional methods was adopted to investigate the distribution and speciation of Cr in a polluted agricultural soil, from the bulk-scale down to the (sub)micro-level. Soil samples were collected from two different points, together with a control sample taken from a nearby unpolluted site. The bulk characterization revealed that the polluted soils contained much higher concentrations of organic matter (OM) and potentially toxic elements (PTE) than the control. Chromium was the most abundant PTE (up to 5160 g kg⁻¹), and was present only as Cr(III), as its oxidation to Cr(VI) was hindered by the high OM content. According to sequential extractions, Cr was mainly associated to the soil oxidisable fraction (74%) and to the residual fraction (25%). The amount of Cr potentially bioavailable for plant uptake (DTPA-extractable) was negligible. Characterization of soil thin sections by micro X-ray fluorescence (μXRF) and field emission scanning electron microscopy coupled with microanalysis (FEGSEM-EDX) showed that Cr was mainly distributed in aggregates ranging from tens micrometres to few millimetres in size. These aggregates were coated with an aluminosilicate layer and contained, in the inner part, Cr, Ca, Zn, P, S and Fe. Hyperspectral elaboration of μXRF data revealed that polluted soils were characterised by an exogenous organic-rich fraction containing Cr (not present in the control), and an endogenous aluminosilicate fraction (present also in the control), coating the Cr-containing aggregates. Analyses by high-resolution micro X-ray computed tomography (μCT) revealed a different morphology of the soil aggregates in polluted soils compared with the control. The finding of microscopic leather residues, combined with the results of bulk- and micro-characterizations, suggested that Cr pollution was likely ascribable to soil amendment with tannery waste-derived matrices. However, over the years, a natural process of Cr stabilization occurred in the soil thus reducing the environmental risks.

This study aims to investigate the distribution of heavy metals (Cd, Pb, Ni, and Mn) in different organs of two marine mussel species, Perna perna collected from Figuier site and Mytilus galloprovincialis sampled from Sercouf and Algiers port sites of the Algerian coast. Thirty individuals (>5 cm length) were seasonally sampled over a 1-year period from each site, and condition index (CI) and gonado somatic index (GSI) of mussels were calculated. The gill, digestive gland, rest of soft tissues, and gonad were accurately isolated and heavy metal contents were analyzed by ICP-MS. Heavy metal results, expressed on μg/g dry weight, ranged from 0.1 to 2.6 Cd, 0.1 to 17.15 Pb, 0.36 to 25.7 Ni, and 3.68 to 74.76 Mn. Thus, typical distribution of studied metals in various organs of mussels was found. In fact, the digestive gland followed by gill revealed significantly high metal concentrations. However, gonad showed low heavy metal contents. Different patterns of heavy metal distribution in various organs of mussels were found at the three sampling sites. High levels of Cd, Pb, Ni, and Mn were detected in mussels of Sercouf, Algiers port, and Figuier sites, respectively. According to the Algerian and European norms, mussels collected from all sites were healthy except those of Algiers port sampled in autumn and winter seasons where lead contamination was found.

Global warming and the associated climate changes are predictable. They are enhanced by burning of fossil fuels and the emission of huge amounts of CO₂ gas which resulted in greenhouse effect. It is expected that the average global temperature will increase with 2–5 °C in the next decades. As a result, the earth will exhibit marked climatic changes characterized by extremer weather events in the coming decades, such as the increase in temperature, rainfall, summertime, droughts, more frequent and stronger tornadoes and hurricanes. Epidemiological disease cycle includes host, pathogen and in certain cases intermediate host/vector. A complex mixture of various environmental conditions (e.g. temperature and humidity) determines the suitable habitat/ecological niche for every vector host. The availability of suitable vectors is a precondition for the emergence of vector-borne pathogens. Climate changes and global warming will have catastrophic effects on human, animal and environmental ecosystems. Pathogens, especially neglected tropical disease agents, are expected to emerge and re-emerge in several countries including Europe and North America. The lives of millions of people especially in developing countries will be at risk in direct and indirect ways. In the present review, the role of climate changes in the spread of infectious agents and their vectors is discussed. Examples of the major emerging viral, bacterial and parasitic diseases are also summarized.

The occurrence of anticancer drugs in the environment has attracted wide attention due to its potential environmental risks. The aim of this study was to investigate degradation characteristics and mechanism of anticancer drug capecitabine (CPC) by electron beam (EB) irradiation. The results showed that EB was an efficient water treatment process for CPC. The degradation followed pseudo-first-order kinetics with dose constants ranged from 1.27 to 3.94 kGy⁻¹. Removal efficiencies in natural water filtered or unfiltered were lower than pure water due to the effect of water matrix components. The degradation was restrained by the presence of NO₂⁻, NO₃⁻ and CO₃²⁻, and fulvic acid due to competition of reactive radical •OH. It demonstrated that oxidizing radical played important role in irradiation process. The appropriate addition of H₂O₂ and K₂S₂O₈ providing with oxidizing agents •OH and •SO₄⁻ was favorable to improve degradation efficiency of CPC. The possible transformation pathways of CPC including cleavage of the ribofuranose sugar and defluorination were proposed based on intermediate products and were consistent with the theoretical calculation of charge and electron density distribution. Toxicity of CPC and intermediate products were estimated by ECOSAR program. It was found that CPC was transformed to low toxicity products with EB.