Monitoring different sources of marine pollution in the Canarian intertidal zone using Anemonia sulcata as a bioindicator.

Sea anemones have often been used as bioindicators of contamination because they are semisessile organisms that rarelly leave their niche, which is why they are conducive to affecting the ecosystem at the local level. The objective of this work is to determine whether the concentrations of heavy metals and trace elements in the anemone Anemonia sulcata vary depending on the source of contamination present. In 2021 seventy specimens were collected at five sampling points and fourteen specimens were collected in each point (Control Zone, Thermal Power Plant, Sewage Pipe, Harbour and Tourism) in 2021, on the island of Tenerife. All the areas studied characterized by a pollution condition had higher concentrations of metals and trace elements than the control area. The anemones from Harbour presented a greater number of metals with a higher concentration than the other study areas.

Count-Based Morgan Fingerprint: A More Efficient and Interpretable Molecular Representation in Developing Machine Learning-Based Predictive Regression Models for Water Contaminants' Activities and Properties.

In this study, we introduce the count-based Morgan fingerprint (C-MF) to represent chemical structures of contaminants and develop machine learning (ML)-based predictive models for their activities and properties. Compared with the binary Morgan fingerprint (B-MF), C-MF not only qualifies the presence or absence of an atom group but also quantifies its counts in a molecule. We employ six different ML algorithms (ridge regression, SVM, KNN, RF, XGBoost, and CatBoost) to develop models on 10 contaminant-related data sets based on C-MF and B-MF to compare them in terms of the model's predictive performance, interpretation, and applicability domain (AD). Our results show that C-MF outperforms B-MF in nine of 10 data sets in terms of model predictive performance. The advantage of C-MF over B-MF is dependent on the ML algorithm, and the performance enhancements are proportional to the difference in the chemical diversity of data sets calculated by B-MF and C-MF. Model interpretation results show that the C-MF-based model can elucidate the effect of atom group counts on the target and have a wider range of SHAP values. AD analysis shows that C-MF-based models have an AD similar to that of B-MF-based ones. Finally, we developed a "ContaminaNET" platform to deploy these C-MF-based models for free use.

Legacy and novel brominated flame retardants in a lab-constructed freshwater ecosystem: Distribution, bioaccumulation, and trophic transfer.

The extensive utilization of both legacy and novel brominated flame retardants (BFRs) leads to high environmental concentrations, which would be bioaccumulated by organisms and further transferred through the food webs, causing potential risks to humans. In this study, five BFRs, that showed high detection frequencies and concentrations in sediments from an e-waste dismantling site in Southern China, namely 2,3,4,5,6-pentabromotoluene (PBT), hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and decabromodiphenyl ether (BDE209), were selected as target pollutants in the lab-constructed aquatic food web as part of a micro-ecosystem, to investigate their distribution, bioaccumulation, and trophic transfer patterns. The significant correlations between different samples in the food web indicated that the dietary uptake appeared to influence the levels of BFRs in organisms. Significant negative correlations were observed between the trophic level of organisms and the lipid-normalized concentrations of BTBPE and DBDPE, indicating the occurrence of trophic dilution after 5-month exposure. However, the average values of bioaccumulation factors (BAFs) were from 2.49 to 5.17 L/kg, underscoring the importance of continued concern for environmental risks of BFRs. The organisms occupying higher trophic levels with greater bioaccumulation capacities may play a pivotal role in determining the trophic magnification potentials of BFRs. This research provides a helpful reference for studying the impacts of feeding habits on bioaccumulation and biomagnification, as well as for identifying the fate of BFRs in aquatic environment.

Occurrence, distribution, and ecological risk assessment of pharmaceuticals and personal care products in the surface water of the middle and lower reaches of the Yellow River (Henan section).

Pharmaceuticals and personal care products (PPCPs) are commonly seen emerging organic contaminants in aquatic environments. The transects for the occurrence and distribution of 24 PPCPs along the middle and lower reaches of the Yellow River (Henan section) were investigated in this study. All 24 targeted compounds were detected in surface water, with concentrations in the range from not detected (ND) to 527.4 ng/L. Among these PPCPs, caffeine is found to have the highest concentration and its detection frequency is 100%. The total PPCP concentration ranged from 136 ng/L to 916 ng/L (median, 319.5 ng/L). Spatial analysis showed that the pollution level of PPCPs in the trunk stream was lower than that in most tributaries in the middle and lower reaches of the Yellow River (Henan section). The ecotoxicological risk assessment indicated that norfloxacin, azithromycin, estrone, and triclosan posed high risks to aquatic organisms (RQ > 1), roxithromycin and oxytetracycline imposed moderate risks (0.1 ≤ RQ < 1), and the tributary Jindi River had the highest mixed risk (MRQ = 222).

Experiences of the Flint Water Crisis Among Reproductive-Age Michigan Women in Communities Outside of Flint: Differences by Race and Ethnicity.

We sought to understand how women in Michigan communities outside of Flint experienced the Flint water crisis, an avoidable public health disaster widely attributed to structural racism. Using survey data from 950 Michigan women aged 18-45 from communities outside of Flint, we examined racial and ethnic differences in personal connections to Flint, perceived knowledge about the water crisis, and beliefs about the role of anti-Black racism in the water crisis factors that could contribute to poor health via increased psychological stress. We found that White (OR = 0.32; 95% CI: 0.22, 0.46) and Hispanic (OR = 0.21; 95% CI: 0.09, 0.49) women had lower odds than Black women of having family or friends who lived in Flint during the water crisis. Compared to Black women, White women were less likely to be moderately or very knowledgeable about the water crisis (OR = 0.58; 95% CI: 0.41, 0.80). White women (OR = 0.26; 95% CI: 0.18, 0.37), Hispanic women (OR = 0.38; 95% CI: 0.21, 0.68), and women of other races (OR = 0.28; 95% CI: 0.15, 0.54) were less likely than Black women to agree that the water crisis happened because government officials wanted to hurt Flint residents. Among those who agreed, White women (OR = 0.47; 95% CI: 0.30, 0.74) and women of other races (OR = 0.33; 95% CI: 0.12, 0.90) were less likely than Black women to agree that government officials wanted to hurt people in Flint because most residents are Black. We conclude that the Flint water crisis was a racialized stressor, with potential implications for the health of reproductive-age Black women.

The effect of arsenic on the structure and composition of stream hyphomycetes assemblages.

Aquatic hyphomycetes are fungi with a fundamental ecological role in forested streams. These organisms are responsible for cycling of nutrients in aquatic environments. However, their structure and composition can be affected when exposed to certain pollutants. Arsenic (As) is a trace element with high toxicity for the aquatic biota. Here we evaluated the effects of different concentrations of Arsenite (AsIII) and Arsenate (AsV) on aquatic hyphomycetes assemblages. To test As toxicity, we conditioned Nectandra megapotamica leaves in a stream and after this period, we incubated leaf discs with stream water and different concentrations of AsIII and AsV. Species richness was negatively affected by both As form. Likewise, the hyphomycetes assemblages presented variation in the composition of species. However, the sporulation rates were not influenced by As. The As showed toxicity on species of hyphomycetes more sensitive, remaining only in species tolerant to its toxicity. In this way, As generated a change in the aquatic hyphomycetes composition. We observed that As had a negative effect on the aquatic hyphomycetes assemblages, regardless of the chemical form. Our results point to the toxicity of this element and its effects on a group that is fundamental to the streams ecosystems functioning.

Microplastics distribution characteristics in typical inflow rivers of Taihu lake: Linking to nitrous oxide emission and microbial analysis.

The microplastics in nature water are important for the environmental fate of nitrous oxide (N2O). This study investigated the influence and microbial mechanism of microplastic abundance to the N2O flux in typical inflow rivers of Taihu lake. The microplastic abundance were in a range of 160-700 particles/m3 surface water, and 514-3018 particles/kg dry sediment. The highest percentage of microplastic color was transparent, significantly higher than other color (p<0.0001) in both surface water and sediment. The dominant microplastic size was 500-5000 µm in surface water, while size lower than 1000 µm was dominant in sediment. The microplastic abundance in sediment was negatively correlated with the concentration of suspended sediments (SPS) (p<0.05), Chl-a (p<0.05), NH4+-N (p<0.05) and TP (p<0.01) in inflow river surface water. The dissolved N2O concentration were 45.71-132.42 nmol/L, and the N2O fluxes were 29.85-276.60 µmol/m2/d. The dissolved N2O concentration was significantly correlated with the nirK abundance and nirK/nosZI ratio negatively (p<0.05), revealed that sediment nirK-type denitrification was the main driver of dissolved N2O. Meanwhile, the N2O flux (water-air interface) was significantly correlated with nosZI, napA, narG and nirS negatively, implied that nitrification and denitrification interaction in sediment is the main influence factor. The denitrification process in sediment was the main driven factor of N2O releasing. Mantel-test shows that microplastic abundance in surface water was significantly correlated with nitrification (p = 0.001∼0.01) and denitrification (p = 0.01∼0.05) genera in water. The dominant denitrification microorganism was Dechloromonas in sediment and Flavobacterium in surface water. These results provided new insight into the fact that plastisphere which comprises microbial community on microplastic could affect the N2O emission in aquatic system.

Inter-comparison of chemical fingerprint and source apportionment of marine fine particles at two islands through the west and east passages of the Taiwan Island.

In this study, the concentrations of marine fine particles (PM2.5) and their chemical fingerprints were inter-compared at two islands located aside from the west and east waters of Taiwan Island and the variability of west and east passages (i.e., Routes A1 and A2) were explored. Marine PM2.5 was simultaneously sampled at the Green and Dongsha Islands and five chemical components (i.e., water-soluble ions, metallic elements, carbonaceous content, anhydrosugars, and organic acids) were further analyzed in PM2.5 to characterize their chemical fingerprints. The highest concentrations of chemical composition and PM2.5 were commonly observed during the Asian Northeastern Monsoons (ANMs) via long-range transport (LRT). Water-soluble ions (WSIs) were dominated by secondary inorganic aerosols (SIAs), and followed by oceanic spray. The major metallic content of PM2.5 was crustal elements, while trace metals originated from anthropogenic sources with an enrichment factor (EF) > 10. In terms of carbonaceous content in PM2.5, organic carbon (OC) was superior to elemental carbon (EC). High levoglucosan concentrations were also observed during the periods of ANMs. Secondary organic aerosols (SOAs) were formed by atmospheric chemical reactions during the LRT procedure. The PM2.5 concentration of Route A1 was 37.51 % higher than that of Route A2, and trace metals (V, Mn, Ni, Pb, Cr, and Cu) increased significantly by 96.16-325.83 %. Positive matrix factorization (PMF) results revealed that the dominant factor of PM2.5 for Route A1 was shipping emissions and vehicular exhausts (41.2 %), while that for Route A2 was oceanic spray (30.2 %). Route A1 was mainly attributed to highly industrialized regions, densely populated urbanized areas, and ship-intensive traffics in East Asia.

Pharmaceutical pollution of the world's rivers.

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Per- and polyfluoroalkyl substances in the environment.

Over the past several years, the term PFAS (per- and polyfluoroalkyl substances) has grown to be emblematic of environmental contamination, garnering public, scientific, and regulatory concern. PFAS are synthesized by two processes, direct fluorination (e.g., electrochemical fluorination) and oligomerization (e.g., fluorotelomerization). More than a megatonne of PFAS is produced yearly, and thousands of PFAS wind up in end-use products. Atmospheric and aqueous fugitive releases during manufacturing, use, and disposal have resulted in the global distribution of these compounds. Volatile PFAS facilitate long-range transport, commonly followed by complex transformation schemes to recalcitrant terminal PFAS, which do not degrade under environmental conditions and thus migrate through the environment and accumulate in biota through multiple pathways. Efforts to remediate PFAS-contaminated matrices still are in their infancy, with much current research targeting drinking water.

A novel random forest approach to revealing interactions and controls on chlorophyll concentration and bacterial communities during coastal phytoplankton blooms.

Increasing occurrence of harmful algal blooms across the land-water interface poses significant risks to coastal ecosystem structure and human health. Defining significant drivers and their interactive impacts on blooms allows for more effective analysis and identification of specific conditions supporting phytoplankton growth. A novel iterative Random Forests (iRF) machine-learning model was developed and applied to two example cases along the California coast to identify key stable interactions: (1) phytoplankton abundance in response to various drivers due to coastal conditions and land-sea nutrient fluxes, (2) microbial community structure during algal blooms. In Example 1, watershed derived nutrients were identified as the least significant interacting variable associated with Monterey Bay phytoplankton abundance. In Example 2, through iRF analysis of field-based 16S OTU bacterial community and algae datasets, we independently found stable interactions of prokaryote abundance patterns associated with phytoplankton abundance that have been previously identified in laboratory-based studies. Our study represents the first iRF application to marine algal blooms that helps to identify ocean, microbial, and terrestrial conditions that are considered dominant causal factors on bloom dynamics.

Multibiomarker responses to polycyclic aromatic hydrocarbons and microplastics in thumbprint emperor Lethrinus harak from a South Pacific locally managed marine area.

To determine the baseline threat of microplastics and polycyclic aromatic hydrocarbons (PAHs) in an important seafood fish from Vueti Navakavu locally managed marine area, a multibiomarker risk assessment was conducted on the thumbprint emperor fish Lethrinus harak. Condition factor, a measure of relative general health condition of fish, was significantly lower in samples from the wet season compared to the dry season but no significant differences were observed for hepatosomatic index, a measure of relative stored energy/nutrition, between seasonal groups. PAHs levels of four metabolites in emperor fish from Fiji waters are reported here for the first time; seasonal groups showed no significant differences, but all samples presented levels of biliary PAHs. Each specimen also contained at least one microplastic in its gastrointestinal system; fibres were the predominant form-type and ingestion levels showed that more than 80% of fragment sizes were below 1.0 mm. Biochemical responses were observed for ethoxyresorufin-O-deethylase and glutathione S-transferase biotransformation activity, oxidative stress (glutathione peroxidase and glutathione reductase activity; lipid peroxidation) and genotoxicity (micronuclei assay). Though there were no statistically significant differences found, there were biological significances that were important to note; relatively low levels of pollutant exposure and low levels of biochemical responses showed enzymes response in thumbprint emperor were as expected to their roles in the body. In this multibiomarker approach, the observation of pollutants presence and histopathological injuries are considered biologically relevant from a toxicological perspective and serve as a baseline for future pollution studies in seafood fishes in Fiji, with site differences and the inclusion of fish species comparison. We recommend adopting a suite of biomarkers in future regional biomonitoring studies to develop holistic baseline information for other marine settings in Fiji and other Pacific Island countries.

Progress in the prevention and control of water-borne arsenicosis in China.

In this report, we provided an overview of the prevalence, control, and prevention of water-borne arsenicosis in China during 2001-2016. Random sampling was continuously performed during 2001-2010 to find villages having high levels of arsenic (>50 µg/L) in drinking water. The high-arsenic-exposure villages with more geographically dispersed water supplies were subsequently analyzed for characteristics of arsenic distribution, and villages with relatively large populations were investigated for arsenicosis. The results showed that among 32,673,677 inhabitants in 36,820 villages, 1,894,587 inhabitants in 2,476 villages were at risk of high arsenic exposure. Among the 33,318 drinking water sources surveyed in 625 high-arsenic-exposure villages, 9,807 drinking water sources that contained high levels of arsenic (>50 µg/L) were identified. The overall prevalence rate of arsenicosis was 1.93%. Further, some representative villages were chosen to monitor arsenicosis annually, showing that the prevalence rate of arsenicosis was lower in villages with arsenic-safe water supplies than in villages without arsenic-safe water supplies. To the best of our knowledge, this report provides the most comprehensive assessment of the distribution of high arsenic exposure and arsenicosis in China until now.

Isolation and genomic characterization of the ibuprofen-degrading bacterium Sphingomonas strain MPO218.

The presence of pharmaceutical compounds in waters and soils is of particular concern because these compounds can be biologically active, even at environmental concentrations. Most pharmaceutical contaminants result from inefficient removal of these compounds during wastewater treatment. Although microorganisms able to biodegrade pharmaceuticals compounds have been described, the isolation and characterization of new bacterial strains capable of degrading drugs remain important to improve the removal of this pollutant. In this work, we describe the Sphingomonas wittichii strain MPO218 as able to use ibuprofen as the sole carbon and energy source. The genome of MPO218 consists of a circular chromosome and two circular plasmids. Our analysis shows that the largest plasmid, named pIBU218, is conjugative and can horizontally transfer the capability of growing on ibuprofen after conjugation with another related bacterium, Sphingopyxis granuli TFA. This plasmid appears to be unstable since it undergoes different deletions in absence of selection when growth on ibuprofen is not selected. This is the first described example of a natural and conjugative plasmid that enables growth on ibuprofen and is another example of how horizontal gene transfer plays a crucial role in the evolution of bacteria.

Predicted growth in plastic waste exceeds efforts to mitigate plastic pollution.

Plastic pollution is a planetary threat, affecting nearly every marine and freshwater ecosystem globally. In response, multilevel mitigation strategies are being adopted but with a lack of quantitative assessment of how such strategies reduce plastic emissions. We assessed the impact of three broad management strategies, plastic waste reduction, waste management, and environmental recovery, at different levels of effort to estimate plastic emissions to 2030 for 173 countries. We estimate that 19 to 23 million metric tons, or 11%, of plastic waste generated globally in 2016 entered aquatic ecosystems. Considering the ambitious commitments currently set by governments, annual emissions may reach up to 53 million metric tons per year by 2030. To reduce emissions to a level well below this prediction, extraordinary efforts to transform the global plastics economy are needed.

Microbial community composition in iron deposits and manganese crusts formed in riverine environments around the Aso area in Japan.

The Kurokawa river flowing through the Aso Caldera in Southwest Japan is influenced by groundwater containing high concentration of dissolved metals (Fe2+ and Mn2+) and is associated with orange deposits in the upstream and thick black crusts on the wall of artificial waterway tunnel with several km lengths in the midstream regions. X-ray fluorescence analysis revealed that the orange deposits contained up to 34.4% Fe and black crusts comprised up to 25.4% and 10.6% Mn and Fe, respectively. Although naturally occurring Mn-oxides and crusts are considered biogenic in pH-neutral freshwater environments, the whole microbial community in Mn crust and their contribution to Mn crust formation in these environments remain unclear. High-throughput molecular sequencing for bacteria and eukaryotes including fungi revealed black Mn crusts had a high abundance of Sphingomonas, Hyphomicrobium, Bacillus, Pseudomonas, and Mortierella, previously reported genera including several species with Mn-oxidizing activity in Mn crusts or nodules of other marine and freshwater environments. In addition, one bacterial isolate and one fungal isolate with Mn-oxidizing activity were obtained from black Mn crust. These results suggest that multiple Mn-oxidizing bacteria including Pseudomonas and fungi are involved in Mn crust formation on the wall of dark waterway tunnel in the oligotrophic environment of the Kurokawa river.

Isolation and Extraction of Microplastics from Environmental Samples: An Evaluation of Practical Approaches and Recommendations for Further Harmonization.

Researchers have been identifying microplastics in environmental samples dating back to the 1970s. Today, microplastics are a recognized environmental pollutant attracting a large amount of public and government attention, and in the last few years the number of scientific publications has grown exponentially. An underlying theme within this research field is to achieve a consensus for adopting a set of appropriate procedures to accurately identify and quantify microplastics within diverse matrices. These methods should then be harmonized to produce quantifiable data that is reproducible and comparable around the world. In addition, clear and concise guidelines for standard analytical protocols should be made available to researchers. In keeping with the theme of this special issue, the goals of this focal point review are to provide researchers with an overview of approaches to isolate and extract microplastics from different matrices, highlight associated methodological constraints and the necessary steps for conducting procedural controls and quality assurance. Simple samples, including water and sediments with low organic content, can be filtered and sieved. Stepwise procedures require density separation or digestion before filtration. Finally, complex matrices require more extensive steps with both digestion and density adjustments to assist plastic isolation. Implementing appropriate methods with a harmonized approach from sample collection to data analysis will allow comparisons across the research community.

Manganese-contaminated groundwater treatment by novel bacterial isolates: kinetic study and mechanism analysis using synchrotron-based techniques.

The occurrence of manganese in groundwater causes coloured water and pipe rusting in water treatment systems. Consumption of manganese-contaminated water promotes neurotoxicity in humans and animals. Manganese-oxidizing bacteria were isolated from contaminated areas in Thailand for removing manganese from water. The selected bacterium was investigated for its removal kinetics and mechanism using synchrotron-based techniques. Among 21 isolates, Streptomyces violarus strain SBP1 (SBP1) was the best manganese-oxidizing bacterium. At a manganese concentration of 1 mg L-1, SBP1 achieved up to 46% removal. The isolate also successfully removed other metal and metalloid, such as iron (81%) and arsenic (38%). The manganese concentration played a role in manganese removal and bacterial growth. The observed self-substrate inhibition best fit with the Aiba model. Kinetic parameters estimated from the model, including a specific growth rate, half-velocity constant, and inhibitory constant, were 0.095 h-1, 0.453 mg L-1, and 37.975 mg L-1, respectively. The synchrotron-based techniques indicated that SBP1 removed manganese via combination of bio-oxidation (80%) and adsorption (20%). The study is the first report on biological manganese removal mechanism using synchrotron-based techniques. SBP1 effectively removed manganese under board range of manganese concentrations. This result showed the potential use of the isolate for treating manganese-contaminated water.

Spatiotemporal Patterns in River Water Quality and Pollution Source Apportionment in the Arid Beichuan River Basin of Northwestern China Using Positive Matrix Factorization Receptor Modeling Techniques.

Deteriorating surface water quality has become an important environmental problem in China. In this study, river water quality was monitored in July (wet season) and October (dry season) 2019 at 26 sites, and a water quality index (WQI) and positive matrix factorization (PMF) model were used to assess surface water quality and identify pollution sources in the Beichuan River basin, Qinghai Province, China. The results showed that 53.85% and 76.92% of TN, 11.54% and 34.62% of TP, 65.38% and 76.92% of Fe, and 11.54% and 15.38% of Mn samples in the dry and wet seasons, respectively, exceeded the Chinese Government's Grade III standards for surface water quality. The spatial variation in water quality showed that it gradually deteriorated from upstream to downstream as a result of human activity. The temporal variation showed that water quality was poorer in the wet season than in the dry season because of the rainfall runoff effect. The PMF model outputs showed that the primary sources of pollution in the wet season were mineral weathering and organic pollution sources, domestic and industrial sewage, and agricultural and urban non-point pollution sources. However, in the dry season, the primary sources were mineral weathering and organic pollution sources, industrial sewage, and domestic sewage. Our results suggest that the point pollution sources (domestic and industrial sewage) should be more strictly controlled, as a priority, in order to prevent the continued deterioration in water quality.