Chemodiversity in freshwater health.

Dissolved organic matter may offer a way to track and restore the health of fresh waters.

Distribution and composition of floating marine debris in Shiretoko peninsula, Japan, using opportunistic sighting survey.

Floating marine debris (FMD) poses several threats to marine species, such as entanglement, ingestion, and the transport of pollutants. The Shiretoko Peninsula, located in northern Japan, is a registered World Natural Heritage Site and a biodiversity hotspot. However, FMD has not yet been thoroughly investigated in this region. In 2022, sighting surveys were conducted in Abashiri (west side of the peninsula) and Rausu (east side) to assess the abundance, composition, and distribution of FMD. The mean densities were notably higher in Abashiri, and there was more fishing-related debris in Rausu. Regarding local human activities, the population and number of tourists are higher in Abashiri, and fishing activities are higher in Rausu. While marine pollution is a global issue, our study suggests that addressing it should commence with community-based management at the local level.

Experimental study on color and texture as cues for plastic debris ingestion by captive sea turtles.

Sea turtles face considerable risks from ingesting marine debris. They are primarily visual feeders, so color may be important for identifying food suitability or enhancing prey detection. Here, we investigated the impacts of color and texture on foraging behavior in relation to plastic consumption. We experimentally assessed the influences of color and texture as attractors for sea turtles using edible jellyfish. The findings showed that the colors of objects significantly affected selective preferences, as evidenced by different behaviors by sea turtles in response to different colors. They exhibited diet-related selectivity toward colors similar to common aquarium food, and texture had a significant impact on complete ingestion. The results suggest that plastic resembling natural prey is more likely ingested. Also, sea turtles were attracted by the color yellow, suggesting that visually distinctive items can attract them. Our results provide fundamental knowledge, helping mitigate the effects of plastic pollution on wildlife.

Floating marine debris influx in the intertidal zone of offshore islands in Bangladesh: A case study of Manpura Island.

Marine Debris is all-pervading in the world's oceans. In this research, for the first time, Floating Marine Debris (FMD) accumulation in the intertidal zone of Manprua island, an offshore island of Bangladesh, is reported. The assessment has been done by integrating both physical investigations and questionnaire survey. The Study shows high debris density on the windward and river-facing sides of the island. The density of debris items in this area varies from 550,000 to 60,000 items per km2 (8.5 to 0.08 g/m2) for transect samples during low tide and 350,000 to 60,000 items per km2 (5.76 to 1.20 g/m2) for net samples during high tide. However, the most damaging debris items are uprooted trees and water hyacinths because they hinder fishing activities. This study provides baseline information on FMD in the Meghna Estuary, which can be used as a reference for sustainable monitoring and management of marine pollution.

Formulation of water pollutant discharge limits for malathion based on nonsensitive aquatic organism protection.

The "Integrated Wastewater Discharge Standard" was implemented for water pollutant discharge in China's pesticide industry, which has no control requirements for particular wastewater pollutants in the industry. In the standard, certain pollutants discharge limits are limited strictly or loosely, resulting in practical management implementation difficulties. In view of the highly selective targeting characteristics of organic pesticide active ingredients in fungicides, insecticides, and herbicides, a method for deriving discharge limits based on the water quality criteria for pesticides for the protection of nonsensitive species is established based on the idea of fully protecting aquatic organisms beyond sensitive objects. Through the use of malathion as an example, by screening its toxicity data in different species of aquatic organisms, the sequence point with the most significant change in the acute toxicity sensitivity of the species is taken as the variation point in the cumulative frequency of the sensitive and nonsensitive species to derive the water quality criteria, using the species sensitivity distribution method as the scientific basis for determining the discharge limits. After a comparative analysis of different simulation models, the sigmoid model, with the best fit, is selected to determine that the sensitive species hazard concentration (HCs) of malathion to aquatic organisms in China is 46.4 µg/L, and the discharge limit derived from the HCs based on the relationship between the environmental capacity and emissions is rounded to 250 µg/L. Studies showed that the relationship between the emissions limit derived from the water quality criteria for protecting nonsensitive species and malathion limit stipulated in the "Environmental Quality Standards for Surface Water" conforms to the corresponding relationship of the quality standard and discharge standard, which can be achieved by current pollution control technology, combined with water quality improvement. The discharge limit offers the advantages of technical accessibility and economic rationality.

Assessment of the water quality and toxicity effects on zebrafish (Danio rerio) of a stream near a phosphorus chemical plant in Guizhou Province, southwestern China.

To reveal the influence of the phosphorus chemical industry (PCI) on regional water environmental quality and safety, the water quality and ecotoxicological effects of a stream near a phosphorus chemical plant (PCP) in Guizhou Province, southwestern China, were investigated based on water samples collected from the stream. The results showed that the average concentrations of NH3-N, TN, P, F-, Hg, Mn, and Ni were 3.14 mg/L, 30.09 mg/L, 3.34 mg/L, 1.18 mg/L, 1.06 µg/L, 45.82 µg/L, and 11.30 µg/L, respectively. The overall water quality of the stream was in the heavily polluted category, and NH3-N, TN, P, F-, and Hg were the main pollution factors. The degree of pollution was in the order of rainy period > transitional period > dry period, and the most polluted sample site was 1100 m from the PCP. After 28 days of exposure to stream water, there was no significant change in the growth parameters of zebrafish. The gills of zebrafish showed a small amount of epithelial cell detachment and a small amount of inflammatory cell infiltration, and the liver tissue displayed a large amount of hepatocyte degeneration with loose and lightly stained cytoplasm. Compared with the control group, the %DNA in tail, tail length, tail moment, and olive tail moment were significantly increased (p < 0.05), indicating that the water sample caused DNA damage in the peripheral blood erythrocytes of zebrafish. The stream water in the PCI area was found to be polluted and exhibited significant toxicity to zebrafish, which could pose a threat to regional ecological security.

Do loggerhead sea turtle (Caretta caretta) gut contents reflect the types, colors and sources of plastic pollution in the Southwest Indian Ocean?

We analyzed plastic debris ingested by loggerheads from bycatch between 2007 and 2021 in the Southwest Indian Ocean (SWIO). We also analyzed plastic debris accumulated on beaches of the east coast of Madagascar as a proxy for ocean plastics to compare the characteristics of beached plastics and plastic ingested by turtles. We conducted a "brand audit" of the plastics to determine their country of origin. An oceanic circulation model was used to identify the most likely sources of plastics in the SWIO. In total, 202 of the 266 loggerheads analyzed had ingested plastics. Plastics categorized as "hard" and "white" were equally dominant in loggerheads and on beaches, suggesting no diet selectivity. Both the brand audit and circulation modeling demonstrated that Southeast Asia is the main source of plastic pollution in the region. This study demonstrates that loggerheads can be used as bioindicators of plastic pollution in the SWIO.

The recovery of European freshwater biodiversity has come to a halt.

Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss1. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity2. Here, using 1,816 time series of freshwater invertebrate communities collected across 22 European countries between 1968 and 2020, we quantified temporal trends in taxonomic and functional diversity and their responses to environmental pressures and gradients. We observed overall increases in taxon richness (0.73% per year), functional richness (2.4% per year) and abundance (1.17% per year). However, these increases primarily occurred before the 2010s, and have since plateaued. Freshwater communities downstream of dams, urban areas and cropland were less likely to experience recovery. Communities at sites with faster rates of warming had fewer gains in taxon richness, functional richness and abundance. Although biodiversity gains in the 1990s and 2000s probably reflect the effectiveness of water-quality improvements and restoration projects, the decelerating trajectory in the 2010s suggests that the current measures offer diminishing returns. Given new and persistent pressures on freshwater ecosystems, including emerging pollutants, climate change and the spread of invasive species, we call for additional mitigation to revive the recovery of freshwater biodiversity.

Transmission of Microcystins in Natural Systems and Resource Processes: A Review of Potential Risks to Humans Health.

The rapid rise of microcystins (MCs) poses a serious threat to global freshwater ecosystems and has become an important issue of global public health. MCs have considerable stability and are the most widely distributed hepatotoxins. It cannot only accumulate in aquatic organisms and transfer to higher nutrients and levels, but also be degraded or transferred during the resource utilization of cyanobacteria. No matter which enrichment method, it will lead to the risk of human exposure. This review summarizes the research status of MCs, and introduces the distribution of MCs in different components of aquatic ecosystems. The distribution of MCs in different aquatic organisms was summarized, and the potential risks of MCs in the environment to human safety were summarized. MCs have polluted all areas of aquatic ecosystems. In order to protect human life from the health threats caused by MCs, this paper also proposes some future research directions to promote MCs control and reduce human exposure to MCs.

Graphene oxide/cellulose nanofibril composite: A high-performance catalyst for the fabrication of an electrochemical sensor for quantification of p-nitrophenol, a hazardous water pollutant.

The detection and quantification of p-Nitrophenol in environmental samples are important for understanding the extent and impact of environmental pollution, protecting human health, ensuring regulatory compliance, and guiding remediation efforts. The main objective of this work was to investigate the electrochemical performance of a graphene oxide/cellulose nanofibril composite (GO/CNF) modified carbon paste electrode (GO/CNF/CPE) for the sensitive and reliable detection of p-nitrophenol in water samples. The transmission electron microscopy (TEM) technique was employed to enlighten the structure of nanocomposites. The electrochemical behavior of the fabricated electrochemical sensor was characterized via differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). Under optimized analytical conditions, the peak current of the analyte showed a wide linear relationship with its concentration in a range of 3.0 nM-210 µM with a low amount of the limit of detection (LOD) value of 0.8 nM determined by the DPV method. The proposed electrochemical sensor demonstrated excellent sensitivity, selectivity, and accuracy metrics in real sample analysis of p-nitrophenol.

Surface dispersion of coastal discharges in North America towards the Great Pacific Garbage Patch.

This research addresses the surface dispersion of coastal discharges in North America that end up at the Great Pacific Garbage Patch. The evolution of the discharged concentration is calculated through statistical simulations using transition matrices and dispersion ellipses, both based on historical records of surface drifter trajectories. The discharge points are adjacent to urban areas distributed along the coast. The preferential routes, times of arrival, and relative contributions of each site to the accumulation area are quantified. A new statistical delimitation of the position, area and orientation of the garbage patch is proposed. Additional experiments suggest that the tracer retention during the summer is influenced by the low-level atmospheric anticyclone in the Northeastern Pacific, which enhances the Ekman drift and hence favours debris convergence. This effect is reduced when the anticyclone weakens in winter, thus decreasing the debris retention and promoting its westward dispersal by the trade winds.

Evaluation of mixture toxicity literature and chemical space: a data centric approach.

Using the Abstract Sifter tool to analyse PubMed, we reveal published mixture related research most commonly relates to water pollutants, pesticides, environmental pollutants, insecticides, soil pollutants, and chemicals described as persistent, bioaccumulative, and toxic. Furthermore, we discern individual chemicals that also identify as priority chemicals in biomonitoring initiatives and using an ontology-based chemical classification, at the level of the chemical subclass, found these priority chemicals overlap with just 9% of the REACH chemical space.

Assessment of selected pharmaceuticals in Riyadh wastewater treatment plants, Saudi Arabia: Mass loadings, seasonal variations, removal efficiency and environmental risk.

Despite increasing interest in pharmaceutical emissions worldwide, studies of environmental contamination with pharmaceuticals arising from wastewater discharges in Saudi Arabia are scarce. Therefore, this study examined occurrence, mass loads and removal efficiency for 15 pharmaceuticals and one metabolite (oxypurinol) from different therapeutic classes in three wastewater treatment plants (WWTPs), in Riyadh city in Saudi Arabia. A total of 144 samples were collected from the influents and effluents between March 2018 and July 2019 and analyzed using Solid Phase Extraction followed by triple quadrupole LC-MS/MS. The average concentrations in the influents and effluents were generally higher than their corresponding concentrations found either in previous Saudi Arabian or global studies. The four most dominant compounds in the influent were acetaminophen, ciprofloxacin, caffeine, and diclofenac, with caffeine and acetaminophen having the highest concentrations ranging between 943 and 2282 µg/L. Metformin and ciprofloxacin were the most frequently detected compounds in the effluents at concentrations as high as 33.2 µg/L. Ciprofloxacin had the highest mass load in the effluents of all three WWTPs, ranging between 0.20 and 20.7 mg/day/1000 inhabitants for different WWTPs. The overall average removal efficiency was estimated high (≥80), with no significant different (p > 0.05) between the treatment technology applied. Acetaminophen and caffeine were almost completely eliminated in all three WWTPs. The samples collected in the cold season generally had higher levels of detected compounds than those from the warm seasons, particularly for NSAID and antibiotic compounds. The estimated environmental risk from pharmaceutical compounds in the studied effluents was mostly low, except for antibiotic compounds. Thus, antibiotics should be considered for future monitoring programmes of the aquatic environment in Saudi Arabia.

Impact of mixing on water quality in the Bosphorus - Implications on sustainable management of wastewater marine discharges.

The study established the water quality modelling of the Bosphorus system, based on hydrodynamic data as well as the results of the water quality survey carried out in the last five years. The model revealed significant decrease in the magnitude of pollutant loads in the upper layer at the exit into The Marmara Sea providing numerical proof that no pollutant transport would take place from sewage discharges to the upper layer. A similar modelling approach was implemented at the Bosphorus/Marmara interface, a significant hotspot as it included two major deep marine outfalls. The results asserted that the entire sewage flow would enter the lower flow in The Bosphorus through the interface without an appreciable mixing with the upper flow. This way, the study provided a significant scientific support for the sustainable management of marine discharges in this area, since they have no physical interference with The Marmara Sea.

Soil solution data from Bohemian headwater catchments record atmospheric metal deposition and legacy pollution.

Soil solution chemistry depends largely on mineralogy and organic matter properties of soil horizons with which they interact. Differing lithologies within a given catchment area can influence variability in soil cation exchange capacities and affect solute transport. Zero-tension and tension lysimeters were used to evaluate the fast transport of solutes in the topsoil vs. slow diffusional matrix flow at the subsoil of three contrasting lithology catchments in a mid-elevation mountain forest. Our aim was to test the feasibility of lysimeters' hydrochemical data as a gauge for legacy subsoil pollution. Due to contrasting lithologies, atmospheric legacy pollution prevailing at the soil-regolith interface is differently yet consistently reflected by beryllium, lead, and chromium soil solution concentrations of the three catchments. Geochemical (dis)equilibrium between the soil and soil matrix water governed the hydrochemistry of the soil solutions at the time of collection, potentially contributing to decreased dissolved concentrations with increased depths at sites with higher soil pH. A complementary isotopic δ18O runoff generation model constrained potential seasonal responses and pointed to sufficiently long water-regolith interactions as to permit important seasonal contributions of groundwater enriched in chemical species to the topsoil levels. Our study also reflects subsoil equilibration with atmospheric solutes deposited at the topsoil and thus provides guidance for evaluating legacy pollution in soil profiles derived from contrasting lithology.

Ribbon-shaped supramolecular solvents: Synthesis, characterization and potential for making greener the microextraction of water organic pollutants.

Liquid-liquid microextraction (LLME) techniques have experienced a tremendous growth over the last years but still face major challenges related to the use of more efficient and environmentally friendly solvents. Supramolecular solvents (SUPRASs) have proved outstanding efficiency in LLME, but many of the experimental conditions required for SUPRAS formation and/or application cannot be considered green or experimentally convenient. This paper was intended to make greener both SUPRAS formation and their application to the LLME of low-concentration organic pollutants in environmental waters. For this purpose, a variety of SUPRASs were produced at room temperature by simply mixing alkyl phosphonates (A6-12PO3H- and A6-12PO3-2) and tetrahexylammonium (He4N+) ions in aqueous media. Among them, the SUPRASs produced from decyl hydrogen phosphonate (DePO3H-) and He4N+ allowed, for the first time, the development of SUPRAS-based LLMEs where the SUPRAS previously synthesized was added to the liquid sample, instead of being formed in situ as usual, which was proved particularly advantageous for analyses involving large sample/SUPRAS volume ratios. At near equimolar amounts of DePO3H- and He4N+, the amphiphile arranged in the SUPRAS as planar ribbons consisting of water (21 ± 3%, w/v) and DePO3H- and He4N+ in the concentration range 1.0-1.4 M. The application of these SUPRASs to LLMEs was proved by extracting carcinogenic polycyclic aromatic hydrocarbons (CPAHs) from drinking (tap and bottled) and natural (river, reservoir and underground) water (recoveries between 84 and 117% with standard deviations varying between 1 and 14%). The developed method was simple (it only required the addition of 500 µL of SUPRAS to 75 mL of sample, stirring and centrifugation), sensitive (method quantitation limits were below the maximum allowed limits set by the EU; were 0.6-7.1 ng L-1) and selective (SUPRAS extracts were directly analyzed by liquid chromatography-fluorimetry). This research proves that SUPRASs can be operationally used in LLMEs similarly to conventional solvents, which should favor their routine application in high-sample throughput laboratories.

Sonochemical construction of hierarchical strontium doped lanthanum trisulfide electrocatalyst: An efficient electrode for highly sensitive detection of ecological pollutant in food and water.

Herbicides are used constantly in agriculture to enhance productivity across the globe. This herbicide monitoring requires utmost importance since its high dose leads to ecological imbalance and a negative impact on the environment. Moreover, a quantification of toxic herbicide is one of the important problems in the food analysis. In this work, deals with the development of a simple, and facile one-pot sonochemical synthesis of strontium doped La2S3 (Sr@La2S3). Morphological and structural characterization confirms the doping of Sr@La2S3 to generate a hierarchical layered structure. The electrochemical performance of modified with rotating disk electrode (RDE) using Sr@La2S3 composite is high, compared to La2S3 and bare electrodes towards the quantitative detection of mesotrione (MTO) in phosphate buffer. Sr@La2S3/RDE showed good sensitivity for MTO detection and it exhibit a range of 0.01-307.01 µM and limit of detection of 2.4 nM. Besides, the selectivity of fabricated electrode is high as it can electrochemically reduce MTO particularly, even in the presence of other chemicals, biological molecules and inorganic ions. The repeatability of MTO detection is high even after 30 days with a lower RSD values. Hence, simple fabrication of Sr@La2S3/RDE could be a novel electrode for the sensitive, selective, and reproducible determination of herbicides in real-time applications.

Polycyclic aromatic hydrocarbons in Fildes Peninsula, maritime Antarctica: Effects of human disturbance.

This study provides the first data on the distribution, sources, and transport dynamics of polycyclic aromatic hydrocarbons (PAHs) in Fildes Peninsula, Antarctica via summertime analyses of lakes, seawater, snow, and air in 2013. Relatively high PAH levels and similar composition profiles (dominance of two- and three-ring PAHs) in the investigated marine and terrestrial environmental matrices were found, indicating substantial primary emissions of petrogenic PAHs. This result was corroborated by nonequilibrium partitioning of atmospheric PAHs caused by release of anthropically-derived lighter PAHs and air mass movement trajectories mainly originated from the Antarctic marginal seas. Notable geographical disparities of PAH pollution in the various types of samples consistently suggested impacts of station-related activities, rather than long-range atmospheric transport, on PAHs in Fildes Peninsula. The lack for temperature dependence for gas-phase concentrations and various molecular diagnostic ratios of atmospheric PAHs demonstrated that the impact of local anthropogenic inputs on air PAH variability supersedes the re-emission effect. The derived air-water and air-snow exchanges of PAHs in this remote region indicated a disequilibrium state, partially associated with intense local emissions of PAHs. PAH outgassing from, and absorption into, lake and marine waters were both observed, probably due to differences in anthropogenic influences among sites, while the net deposition of gaseous PAHs into snow prevailed. The results of this study shed lights on the major importance of native anthropogenic sources in the footprint and fate of PAHs in the Fildes Peninsula, which merits further monitoring.