Width of vegetated buffer strips to protect aquatic life from pesticide effects.

Vegetated buffer strips (VBS) are an effective measure to retain pesticide inputs during rain events. Numerous studies have examined the retention effects of VBS on pesticides. However, no study has addressed on a large scale with event-related peak concentrations how wide the VBS should be to avoid ecological impacts on aquatic life. Here, we investigated for 115 lowland stream sections in Germany the relevance of environmental and physico-chemical parameters to determine the in-stream pesticide concentration and their ecological risks. Based on peak concentrations related to rain events with precipitation amount resulting in VBS relevant surface runoff for 30 of the 115 investigated stream sections (25 to 70 mm/d), we demonstrated that the average width of VBS was the main parameter (R² = 0.38) reducing the pesticide input ratio, indicating a relevant proportion of surface runoff contributing to the total in-stream pesticide concentrations. Additionally, dry ditches within agricultural fields increased pesticide input (R² = 0.31). Generally, substances classified as slightly mobile were better retained by VBS than mobile substances. Other factors including slope, land use and vegetation cover of VBS had only a minor influence. We assessed the ecological risk of in-stream pesticide concentrations by quantifying exceedances of regulatory- (RAC) and field-validated acceptable concentrations (ACfield). We then translated this ecological risk into protective VBS width by calculating the quotient of in-stream concentration and threshold (RQ). We estimate that a VBS width of 18 m is sufficient to meet the RQACfield protection goal for 95% of streams. The presence of dry ditches increased the protective VBS width to 32 m. In current agricultural practice, however, 26% of the water stretches investigated do not comply with the prescribed 5 m VBS. An extension of the VBS area to 18 m would demand 3.8% of agricultural land within the catchments. A 50% reduction in pesticide use, as required by the European green deal, would still result in 39% (RAC) and 68% (ACfield) of event-related samples being exceeded. Consequently, we see the extension of the VBS width as the most efficient mearsure to sustainably reduce pesticide concentrations in small streams.

EPA Takes Action Against Harmful "Forever Chemicals" in the US Water Supply.

This Medical News article discusses new EPA advisories for a class of synthetic chemical compounds known as PFAS, which are ubiquitous in the environment and in humans, as well as new National Academies guidance on expanded testing for exposure.

High seas treaty within reach.

The ocean is Earth's greatest climate mitigator, but it cannot do its work without biodiversity. Yet, accelerating climate change, unsustainable fishing, and widespread plastic and other pollutants, combined with increased resource demands, are threatening life throughout our global ocean. This is particularly acute in the two-thirds of the ocean (the high seas and seabed below) located beyond national boundaries, and as such, no state can solve these problems alone. Since 2018, member states of the United Nations have been crafting an international treaty to protect high-seas biodiversity and to ensure that human pressures are kept to a level that sustains this variety. Last month, the fifth and supposedly final session of the UN Intergovernmental Conference fell short of this goal. Unfortunately, disagreements on fundamental issues meant that negotiators ran out of time. Achieving a timely treaty requires resuming the dialogue as soon as possible with more visible public and political support to surmount remaining hurdles.

It takes a (microbial) village to make an algal bloom.

More than nutrient levels may drive toxic lake growths.

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.

Environmental Effects of Ultraviolet (UV) Filters.

Organic and inorganic ultraviolet (UV) filters are used in topical sunscreens and other applications to prevent or limit damage following exposure to UV light. Increasing use of UV filters has contributed to a growing number of investigations examining potential effects on human health and the environment. Worldwide environmental monitoring data demonstrate that UV filters reach aquatic environments through two main input sources - direct (i.e., washoff from swimmers/bathers) and indirect (i.e., incomplete wastewater treatment removal) - and can be taken up by various algal, plant, and animal species and sediments. In areas where industrial wastewater sources or significant recreational activities result in a greater input load, levels may be elevated and could impart an increased risk on native species health. In vitro, at higher levels typically not measured in the environment, effects on growth and reproduction are observed in different species, including fish, coral reef, and plants. Despite this, predicted no-effect concentrations for UV filters are generally above measured environmental concentrations. Recent legislative activity banning the use of certain UV filters has heightened awareness of their environmental ubiquity and precipitated a need for a thorough examination of evidence linking their ecological presence with adverse outcomes. In order to gauge the true potential risk to native ecosystems associated with UV filters, future studies should consider factors inherent both to finished sunscreen products (e.g., metabolic fate/transport and effect of inactive ingredients) and to the sampled environment (e.g., species sensitivity, presence of other contaminants, water flow, and photodegradation).

Interpreting Risk from Sunscreens in the Marine Environment.

Recent and pending bans in specific jurisdictions of some organic ultraviolet (UV) filters have resulted in significant concern and controversy over the potential impacts of these contaminants in the marine environment. Organic UV filters have been quantified in the aquatic environment as contaminants in water, sediments, and the tissues of aquatic organisms. The limited available laboratory studies on the toxicity of UV filters to keystone marine species such as reef-building corals describe a wide variety of impacts, from significant acute effects to no observed effects. However, interpretation of results is complicated by differences in methodology, and exposures to single agents in vitro may not reflect the effects of longer exposure to finished sunscreens containing UV filters in combination with numerous other chemicals. Relatively short-term observations of laboratory effects thus may not translate to real-life field conditions, where organisms may be subject to the effects of long-term chronic exposure to UV filters as well as other environmental contaminants and stressors. The lack of current understanding of the full impacts of UV filters, both in the laboratory and in the environment, represents a significant challenge in interpreting the environmental risk associated with the widespread use of sunscreens.

Extreme Biomimetics: Designing of the First Nanostructured 3D Spongin-Atacamite Composite and its Application.

The design of new composite materials using extreme biomimetics is of crucial importance for bioinspired materials science. Further progress in research and application of these new materials is impossible without understanding the mechanisms of formation, as well as structural features at the molecular and nano-level. It presents a challenge to obtain a holistic understanding of the mechanisms underlying the interaction of organic and inorganic phases under conditions of harsh chemical reactions for biopolymers. Yet, an understanding of these mechanisms can lead to the development of unusual-but functional-hybrid materials. In this work, a key way of designing centimeter-scale macroporous 3D composites, using renewable marine biopolymer spongin and a model industrial solution that simulates the highly toxic copper-containing waste generated in the production of printed circuit boards worldwide, is proposed. A new spongin-atacamite composite material is developed and its structure is confirmed using neutron diffraction, X-ray diffraction, high-resolution transmission electron microscopy/selected-area electron diffraction, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy. The formation mechanism for this material is also proposed. This study provides experimental evidence suggesting multifunctional applicability of the designed composite in the development of 3D constructed sensors, catalysts, and antibacterial filter systems.

Defining the Human-Biota Thresholds of Toxicological Concern for Organic Chemicals in Freshwater: The Proposed Strategy of the LIFE VERMEER Project Using VEGA Tools.

Several tons of chemicals are released every year into the environment and it is essential to assess the risk of adverse effects on human health and ecosystems. Risk assessment is expensive and time-consuming and only partial information is available for many compounds. A consolidated approach to overcome this limitation is the Threshold of Toxicological Concern (TTC) for assessment of the potential health impact and, more recently, eco-TTCs for the ecological aspect. The aim is to allow a safe assessment of substances with poor toxicological characterization. Only limited attempts have been made to integrate the human and ecological risk assessment procedures in a "One Health" perspective. We are proposing a strategy to define the Human-Biota TTCs (HB-TTCs) as concentrations of organic chemicals in freshwater preserving both humans and ecological receptors at the same time. Two sets of thresholds were derived: general HB-TTCs as preliminary screening levels for compounds with no eco- and toxicological information, and compound-specific HB-TTCs for chemicals with known hazard assessment, in terms of Predicted No effect Concentration (PNEC) values for freshwater ecosystems and acceptable doses for human health. The proposed strategy is based on freely available public data and tools to characterize and group chemicals according to their toxicological profiles. Five generic HB-TTCs were defined, based on the ecotoxicological profiles reflected by the Verhaar classes, and compound-specific thresholds for more than 400 organic chemicals with complete eco- and toxicological profiles. To complete the strategy, the use of in silico models is proposed to predict the required toxicological properties and suitable models already available on the VEGAHUB platform are listed.

Centralized softening as a solution to chloride pollution: An empirical analysis based on Minnesota cities.

Chloride is a key component of salt, used in many activities such as alkali production, water treatment, and de-icing. Chloride entering surface and groundwater is a concern due to its toxicity to aquatic life and potential to degrade drinking water sources. Minnesota being a hard-water state, has a high demand for water softening. Recent research has found that home-based water softeners contribute significantly to chloride loading at municipal wastewater treatment plants (WWTPs). Because of this, many WWTPs would now require water quality based effluent limits (WQBELs) to comply with the state's chloride water quality standards (WQS), unless they install chloride treatment technologies, which are limited and cost-prohibitive to most communities. A potential solution to this problem, is shifting from home-based water softening to a system where water is softened at drinking water plants, before reaching homes, i.e. centralized softening, analyzed in this paper based on its ability to address both chloride pollution and water softening needs, at reasonable cost. We estimate lifetime costs of three alternative solutions: centralized softening, home-based softening, and a Business as Usual (BAU) or baseline alternative, using annualized 20-year loan payments and Net Present Value (NPV), applied to 84 Minnesota cities with matching data on drinking water plants and WWTPs. We find that centralized softening using either Reverse Osmosis (RO) or lime-softening technologies is the more cost-effective solution, compared to the alternative of home-based softening with end-of-pipe chloride treatment, with a cost ratio in the range 1:3-1:4. Between the two centralized softening options, we find RO-softening to be the lower cost option, only slightly more costly (1.1 cost ratio) than the BAU option. Considering additional environmental and public health benefits, and cost savings associated with removal of home-based softeners, our results provide helpful information to multiple stakeholders interested in an effective solution to chloride pollution.

In vitro microcosm of co-cultured bacteria for the removal of hexavalent Cr and tannic acid: A mechanistic approach to study the impact of operational parameters.

Industrial wastes, for instance, tannery wastes are rich soups of resistant and bioremediation-potent bacteria. In the present work, Chromium (Cr) and tannic acid (TA) resistance bacterial strains were isolated from tannery effluent and identified as Bacillus subtilis (MCC 3275) and Bacillus safensis (MCC 3283) based on its 16S Ribosomal RNA homology. Hexavalent Cr is highly toxic and mutagenic due to its high mobility and reactivity. Whereas, TA is known to inhibit enzyme activity, substrate deprivation, and interaction with membranes and matrix-metal ions. The developed In vitro co-cultured microcosm of B. subtilis and B. safensis was able to remove Cr(VI) up to 95% and TA up to 23%. The bacteria cultures separately were able to degrade Cr(VI) to 88% by B. subtilis and 91% by B. safensis and TA up to 27%. Plackett Burman design (PBD) followed by Response surface methodology (RSM) was applied for the optimization of physio-chemical parameters. The optimized conditions for co-culture development were recorded as K2HPO4 = 0.2 g/L, MgSO4 = 0.2 g/L, NH4Cl = 0.5 g/L, glucose - 0.2 g/L, TA - 5%, Cr = 200 ppm, incubation period of 96 h, agitation speed of 110 rpm, pH = 5.0, temperature= 30 °C and inoculum size = 3%. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) revealed the thorough mechanism of cellular uptake followed by degradation of Cr(VI) and TA. The efficiency of co-culture for other heavy metals was observed as follows: Zn 65%, Pb 63%, Cd 65%, and Ni 65%. Bioremediation using bacteria is an economical and environmentally better alternative to conventional remediation methods. The isolated bacteria are useful in the effluent treatment of tannery or related industries and in metal recovery in mining processes.

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.

Magnetic nanotechnology for diclofenac remediation: molecular basis of drug adsorption and neurobehavioral toxicology as a preliminary study for safe application.

Diclofenac is a commercial non-steroidal anti-inflammatory drug commonly present as a pollutant in naturally occurring water sources and wastewaters. In this work, the adsorption of diclofenac onto chitosan-coated magnetic nanosystems is proposed as a possible tool for remediation. Experimental and theoretical studies have been carried out to reveal the mechanisms associated with diclofenac interactions among all the components of the nanosystem. Mechanisms are presented, analyzed and discussed. A toxicological study in mice was carried out to evaluate the parameters associated with neurotoxicity of the nanodevice. The elucidation of the mechanisms implied in the adsorption process of diclofenac onto magnetic chitosan nanocomposites suggests that diclofenac remediation from water is possible by adsorption onto chitosan. The strategy innovates the commonly used methodologies for diclofenac remediation from pharmaceutical wastes. This magnetic nanotechnology would not induce damage on the nervous system in a murine model, in case of traces remaining in water sources.

Direct growth of m-BiVO4@carbon fibers for highly efficient and recyclable photocatalytic and antibacterial applications.

Owing to photocatalytic and antibacterial properties, bismuth based oxides has drawn much attention in recent past. However, non-recyclability of these oxides has restricted their practical applications. In present work, a novel nanostructured composite monoclinic bismuth vanadate@ activated carbon fibers (BiVO4@ACF) photocatalyst was efficaciously synthesized using a solvothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Bruner-Emmett-Teller (BET). The specific surface area, phase composition, microstructure, binding and photocatalytic activity of BiVO4@ACF pose great dependence on solvent nature and chelating agents utilized for synthesis. The photocatalytic and antibacterial potential of this composite was evaluated and optimized by using a model pollutant, Reactive Rhodamine Blue (RhB) and pathogenic microbes (Escherichia coli and Staphylococcus aureus). The composite possesses enhanced photocatalytic and antibacterial activity and was reutilized for three rounds of respective reaction without any loss of activity and structure as evident from SEM and XRD results. The photocatalytic mechanism of photodegradation of dye and bactericidal properties of samples under visible light irradiation was determined by scavenger and photoluminescence (PL) spectroscopy. The enhanced photocatalytic and antibacterial activity, chemical stability and most importantly good recyclability of BiVO4@ACFs highlight the potential application of this composite in water purification and other biological applications.

Improved filtration for dye removal using keratin-polyamide blend nanofibrous membranes.

Dyes from industrial wastewaters represent one of the most hazardous pollutants as they are not effectively biodegradable. The present work is focused to study the novel properties of keratin-polyamide blend nanofibrous filtration membranes for treating wastewaters containing dye. Keratin protein was extracted from goat hair, a tannery waste through sulphitolysis process. The extracted keratin was blended with polyamide to prepare a nanofibrous membrane through the electrospinning process. The fabricated pristine polyamide and keratin-altered polyamide membranes were characterized and compared for their properties. Effects of solution pH, dye concentration, membrane flux, and membrane capacity have been examined. Very fine nanofibers and enhanced porosity drive the membrane to enhanced flux and higher filtration efficiencies. At pH 2, the dye removal efficiency of the blend membranes was 100, 99, 98, 90, and 83% for 100, 200, 250, 300, and 400 ppm concentrations of dye, respectively. The keratin-polyamide blend membrane exhibited better properties in all aspects. The results of this present investigation indicate that the presence of keratin in filtration membranes is promising for dye removal from the effluents.

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.

Plasmon-enabled degradation of organic micropollutants in water by visible-light illumination of Janus gold nanorods.

The development of sustainable methods for the degradation of pollutants in water is an ongoing critical challenge. Anthropogenic organic micropollutants such as pharmaceuticals, present in our water supplies in trace quantities, are currently not remediated by conventional treatment processes. Here, we report an initial demonstration of the oxidative degradation of organic micropollutants using specially designed nanoparticles and visible-wavelength sunlight. Gold "Janus" nanorods (Au JNRs), partially coated with silica to enhance their colloidal stability in aqueous solutions while also maintaining a partially uncoated Au surface to facilitate photocatalysis, were synthesized. Au JNRs were dispersed in an aqueous solution containing peroxydisulfate (PDS), where oxidative degradation of both simulant and actual organic micropollutants was observed. Photothermal heating, light-induced hot electron-driven charge transfer, and direct electron shuttling under dark conditions all contribute to the observed oxidation chemistry. This work not only provides an ideal platform for studying plasmonic photochemistry in aqueous medium but also opens the door for nanoengineered, solar-based methods to remediate recalcitrant micropollutants in water supplies.

Spatiotemporal Patterns of Impervious Surface Area and Water Quality Response in the Fuxian Lake Watershed.

The increase of urbanization level has led to the rapid increase of impervious surface area (ISA). The aim of this work is to clarify the relationship between the ISA and water quality and lay a foundation for the improvement and protection of the water quality in the basin. Taking the Fuxian Lake Basin in Yunnan Province as an example, based on the Landsat ETM+ remote sensing image and the Gram-Schmidt (GS) image fusion algorithm, the four-terminal model and the linear spectral mixture model (LSMM) were used to extract the impervious surface of the watershed from 2006 to 2015. And statistical methods were used to distinguish its relationship with water quality. The results show that the four-terminal model and the linear spectral mixture model can effectively extract the impervious surface information of the Fuxian Lake Basin. The average root mean square error (RMS) of the image decomposition results from 2006 to 2015 was less than 0.02. In the past 10 years, the ISA has changed significantly in the Fuxian Lake Basin. The ISA showed an overall upward trend from 2006 to 2015. It increased from 24.73 km2 in 2006 to 35.14 km2 in 2015, an increase of 10.81 km2. From the value anomaly, the ISA in 2006 and 2009 is lower than the multiyear average, and those in the other years are higher than the multiyear average. The percentage of ISA in the basin was significantly positively correlated with Chemical Oxygen Demand-Mn (CODMn) and total phosphorus (TP) (r is 0.772, 0.763), and the correlation in the flooding season was greater than that in the dry season. The ISA threshold for water quality deterioration is around 10% in the Fuxian Lake Basin. Reducing ISA coverage, controlling ISA to less than 10%, and preventing nonpoint source pollution during flooding season will be the best measures to effectively improve the water quality environment in the basin.