Contaminants of emerging concern in water and sediment of the Venice Lagoon, Italy.

This study investigates for the first time the contamination of water and sediment of the Venice Lagoon by twenty Contaminants of Emerging Concern (CECs): three hormones, six pharmaceutical compounds (diclofenac and five antibiotics, three of which are macrolides), nine pesticides (methiocarb, oxadiazon, metaflumizone, triallate, and five neonicotinoids), one antioxidant (BHT), and one UV filter (EHMC). Water and sediment samples were collected in seven sites in four seasons, with the aim of investigating the occurrence, distribution, and possible emission sources of the selected CECs in the studied transitional environment. The most frequently detected contaminants in water were neonicotinoid insecticides (with a frequency of quantification of single contaminants ranging from 73% to 92%), and EHMC (detected in the 77% of samples), followed by BHT (42%), diclofenac (39%), and clarithromycin (35%). In sediment the highest quantification frequencies were those of BHT (54%), estrogens (ranging from 35% to 65%), and azithromycin (46%). Although this baseline study does not highlight seasonal or spatial trends, results suggested that two of the major emission sources of CECs in the Venice Lagoon could be tributary rivers from its drainage basin and treated wastewater, due to the limited removal rates of some CECs in WWTPs. These preliminary results call for further investigations to better map priority emission sources and improve the understanding of CECs environmental behavior, with the final aim of drawing up a site-specific Watch List of CECs for the Venice Lagoon and support the design of more comprehensive monitoring plans in the future.

Autistic Regression and Exposure to Industrial Chemicals: Preliminary Observations.

Exposure to industrial pollutants is a potential risk factor not fully explored in ASD with regression (ASD+R). We studied geographical collocation patterns of industrial air chemical emissions and the location of homes of children with ASD+R at different exposure times, compared with ASD cases without regression (ASD-R). Fifteen of 111 emitted chemicals collocated with ASD+R, and 65 with ASD-R. ASD+R collocated more strongly with different neurotoxicants/immunotoxicants a year before diagnosis, whereas ASD-R were moderately collocated with chemicals across all exposure periods. This preliminary exploratory analysis of differences in exposure patterns raises a question regarding potential pathophysiological differences between the conditions.

Multi-class organic pollutants in atmospheric particulate matter (PM2.5) from a Southwestern Europe industrial area: Levels, sources and human health risk.

The occurrence of 50 multi-class pollutants comprising 18 polycyclic aromatic hydrocarbons (PAHs), 12 phthalate esters (PAEs), 12 organophosphorus flame retardants (OPFRs), 6 synthetic musk compounds (SMCs) and 2 bisphenols was studied in atmospheric particulate matter (PM2.5) samples collected at an industrial area focused on automotive manufacturing located at the Southwestern Atlantic European region (Vigo city, Spain) during 1-year period. Among all quantitated pollutants in PM2.5 samples, bisphenol A (BPA) was the most predominant with an average concentration of 6180 pg m-3, followed by PAHs comprising benzo(b+j)fluoranthene (BbF + BjF) and benzo(g,h,i)perylene (BghiP), accounting for 546 pg m-3 and 413 pg m-3 respectively. In addition, two OPFRs concerning tris(chloropropyl) phosphate (TCPP) and triphenyl phosphine oxide (TPPO) were the next following the concentration order, accounting for 411 pg m-3 and 367 pg m-3 respectively; being butyl benzyl phthalate (BBP) the most profuse PAE (56.1 pg m-3 by average). High relative standard deviations (RSDs) were observed during the whole sampling period, while statistically significant differences were only observed for PAHs concentrations during cold and warm seasons. Furthermore, some water-soluble ions and metal(oid)s were analysed in PM2.5 samples to be used as PM source tracers, whose concentrations were quite below the target levels set in the current legislation. Data obtained from principal component analysis (PCA) and PAHs molecular indices suggested a pyrogenic and petrogenic origin for PAHs, whereas occurrence of the remaining compounds seems to be attributed to resources used in the automotive industrial activity settled in the sampling area. Moreover, although a substantial anthropogenic source to PM2.5 in the area was observed, marine and soil resuspension contributions were also accounted. Finally, carcinogenic and non-carcinogenic risks posed by PM2.5-bound pollutants inhalation were assessed, being both averages within the safe level considering the whole period.

Efficacy of water-based skin decontamination of occupational chemicals using in vitro human skin models: a systematic review.

Percutaneous absorption of chemicals is a potential route of topical and systemic toxicity. Skin decontamination interrupts this process by removing contaminants from the skin surface. Decontamination using water-only or soap and water solutions is the current gold standard despite limited efficacy data. A summary of studies evaluating their efficacy in decontaminating occupational contaminants from in vitro human skin models is presented. Embase, MEDLINE, PubMed, Web of Science, and Google Scholar were searched for relevant articles and data extracted from 15 investigations that reported on 21 occupational contaminants, which were further classified as industrial chemicals, drugs, or pesticides. Water-only decontamination yielded no response in 4.3% (n = 6/140) and partial decontamination in 95.7% (n = 134/140) of skin samples. Soap and water decontamination yielded complete decontamination in 4.9% (n = 13/264) and partial decontamination in 95.1% (n = 251/264) of skin samples. Four studies (26.7%, n = 4/15) reported increased penetration rates or skin concentration of contaminants following decontamination, demonstrating a "wash-in" effect. Varying study methodologies hinder our ability to compare data and determine when water alone or soap and water are best used. International harmonized efficacy protocol might enhance our decontamination understanding and enable a more customized approach to decontamination clinical practice and research.

Current EU regulatory requirements for the assessment of chemicals and cosmetic products: challenges and opportunities for introducing new approach methodologies.

The EU Directive 2010/63/EU   on the protection of animals used for scientific purposes and other EU regulations, such as REACH and the Cosmetic Products Regulation advocate for a change in the way toxicity testing is conducted. Whilst the Cosmetic Products Regulation bans animal testing altogether, REACH aims for a progressive shift from in vivo testing towards quantitative in vitro and computational approaches. Several endpoints can already be addressed using non-animal approaches including skin corrosion and irritation, serious eye damage and irritation, skin sensitisation, and mutagenicity and genotoxicity. However, for systemic effects such as acute toxicity, repeated dose toxicity and reproductive and developmental toxicity, evaluation of chemicals under REACH still heavily relies on animal tests. Here we summarise current EU regulatory requirements for the human health assessment of chemicals under REACH and the Cosmetic Products Regulation, considering the more critical endpoints and identifying the main challenges in introducing alternative methods into regulatory testing practice. This supports a recent initiative taken by the International Cooperation on Alternative Test Methods (ICATM) to summarise current regulatory requirements specific for the assessment of chemicals and cosmetic products for several human health-related endpoints, with the aim of comparing different jurisdictions and coordinating the promotion and ultimately the implementation of non-animal approaches worldwide. Recent initiatives undertaken at European level to promote the 3Rs and the use of alternative methods in current regulatory practice are also discussed.

Decontamination efficacy of soapy water and water washing following exposure of toxic chemicals on human skin.

Aim of the study: Following exposure to toxic chemicals, skin uptake is a potential route of intoxication. Therefore, efficient methods for rapid skin decontamination to mitigate systemic effects are of utmost importance. In operational guidelines, skin decontamination is recommended to be performed by dry absorption and washing with water or soapy water. In the present study, evaluation of decontamination efficacy using water or soapy water was performed for five chemicals, three toxic industrial chemicals and two simulants for chemical warfare agents.Materials and methods: Decontamination was initiated at time points 5, 15, 45 and 120 min after exposure in order to evaluate the time window for efficient decontamination. Experiments were conducted utilizing an in vitro skin penetration model to allow exposure of toxic chemicals on human skin. Results: For all test substances, it was clearly demonstrated that decontamination had greater efficacy when initiated at the earliest time-point while decontamination after 120 min was less efficient. Adding soap to the water showed no significant improvement for any of the tested substances.Conclusion: These results are of reledvance for the development of efficient operational decontamination procedures.

Biocatalytic concepts for synthesizing amine bulk chemicals: recent approaches towards linear and cyclic aliphatic primary amines and ω-substituted derivatives thereof.

In this mini-review, an overview about various developed strategies for accessing industrially relevant primary n-alkyl amines via reductive amination by means of amine dehydrogenases as well as transaminases is given. Such transformations were combined with in situ cofactor recycling methodologies avoiding the need for addition of external stoichiometric amounts of organic co-substrates. These methods comprise the application of natural photosynthesis with algae when using carbonyl compounds as substrates as well as the utilization of alcohols as substrates in combination with self-sufficient biocatalytic systems. As such a feature is of utmost importance for large-scale biotransformations in the field of bulk chemicals, which represent high-volume but low-price chemicals, the achievements open up a perspective for biocatalysis also in the area of commodity chemicals. Besides approaches to n-alkyl amines and cyclohexylamine, recently also biocatalytic cascades towards n-alkyl amines bearing functionalities in the ω-position such as a carboxylic acid ester or amino group were reported. It is noteworthy that for ω-aminolauric acid, such a process has already been demonstrated on pilot plant scale.

Characterization of Carboxylic Acid Reductases for Biocatalytic Synthesis of Industrial Chemicals.

Carboxylic acid reductases (CARs) catalyze the reduction of a broad range of carboxylic acids into aldehydes, which can serve as common biosynthetic precursors to many industrial chemicals. This work presents the systematic biochemical characterization of five carboxylic acid reductases from different microorganisms, including two known and three new ones, by using a panel of short-chain dicarboxylic acids and hydroxy acids, which are common cellular metabolites. All enzymes displayed broad substrate specificities. Higher catalytic efficiencies were observed when the carbon chain length, either of the dicarboxylates or of the terminal hydroxy acids, was increased from C2 to C6 . In addition, when substrates of the same carbon chain length are compared, carboxylic acid reductases favor hydroxy acids over dicarboxylates as their substrates. Whole-cell bioconversions of eleven carboxylic acid substrates into the corresponding alcohols were investigated by coupling the CAR activity with that of an aldehyde reductase in Escherichia coli hosts. Alcohol products were obtained in yields ranging from 0.5 % to 71 %. The de novo stereospecific biosynthesis of propane-1,2-diol enantiomer was successfully demonstrated with use of CARs as the key pathway enzymes. E. coli strains accumulated 7.0 mm (R)-1,2-PDO (1.0 % yield) or 9.6 mm (S)-1,2-PDO (1.4 % yield) from glucose. This study consolidates carboxylic acid reductases as promising enzymes for sustainable synthesis of industrial chemicals.

Fourier Transform Infrared Absorption Spectroscopy for Quantitative Analysis of Gas Mixtures at Low Temperatures for Homeland Security Applications.

Performance standard specifications for point chemical vapor detectors are established in ASTM E 2885-13 and ASTM E 2933-13. The performance evaluation of the detectors requires the accurate delivery of known concentrations of the chemical target to the system under test. Referee methods enable the analyte test concentration and associated uncertainties in the analyte test concentration to be validated by independent analysis, which is especially important for reactive analytes. This work extends the capability of a previously demonstrated method for using Fourier transform infrared (FT-IR) absorption spectroscopy for quantitatively evaluating the composition of vapor streams containing hazardous materials at Acute Exposure Guideline Levels (AEGL) to include test conditions colder than laboratory ambient temperatures. The described method covers the use of primary reference spectra to establish analyte concentrations, the generation of secondary reference spectra suitable for measuring analyte concentrations under specified testing environments, and the use of additional reference spectra and spectral profile strategies to mitigate the uncertainties due to impurities and water condensation within the low-temperature (7 °C, -5 °C) test cell. Important benefits of this approach include verification of the test analyte concentration with characterized uncertainties by in situ measurements co-located with the detector under test, near-real-time feedback, and broad applicability to toxic industrial chemicals.

Rethinking guideline toxicity testing.

The guidelines for risk assessment of plant protection products (PPPs) and other non-pharmaceuticals were developed over three decades ago and have generally not been updated to incorporate advancements in toxicology and exposure sciences. These guidelines recommend using maximum-tolerated-dose (MTD) even when human relevance of such high doses is mostly limited due to orders of magnitude margin-of-exposure. Conducting animal studies at such high doses often requires further mode-of-action (MoA) studies elucidating human relevance. In order to improve data, ILSI/HESI-ACSA technical committee proposed a tiered approach with emphasis on determining systemic dose of parent and/or metabolite(s) in test animals as biological effects are reflective of systemic rather than administered dose. Any deviation from linearity in systemic dose (saturation of absorption or elimination) in animal studies may have profound toxic effect(s) not expected to occur in likely human exposure scenarios and should be avoided. Toxicity studies should ideally be conducted at kinetically linear doses or slightly above the point of departure from linearity or kinetically-derived maximum dose (KMD) as the systemic dose nonlinearity is a more sensitive parameter occurring much earlier than the MTD endpoints. Therefore, determining systemic dose, especially KMD, in study animals is an improvement to hazard assessment of PPPs and other non-pharmaceuticals allowing toxicologists to better understand findings in animals at systemically linear as well as nonlinear doses to likely human exposures which can easily be accomplished using core study animals as outlined below. Determining systemic dose in studies will also increase the understanding of initial potential MoA of a PPPs and other non-pharmaceuticals and reduce the use of animals by avoiding unnecessary additional MoA studies.

Development of haemostatic decontaminants for the treatment of wounds contaminated with chemical warfare agents. 1: evaluation of in vitro clotting efficacy in the presence of certain contaminants.

The treatment of penetrating, haemorrhaging injuries sustained within a hazardous environment may be complicated by contamination with toxic chemicals. There are currently no specific medical countermeasures for such injuries. Haemostats with an absorbent mechanism of action have the potential to simultaneously stop bleeding and decontaminate wounds. However, a primary requirement of a 'haemostatic decontaminant' is the retention of clotting function in the presence of chemical contaminants. Thus, the aim of this study was to investigate the haemostatic efficacy of seven commercially available haemostats in the presence of toxic chemicals (soman, VX, sulphur mustard, petrol, aviation fuel and motor oil). Clot viscosity was assessed ex vivo using thrombelastography following treatment of pig blood with: (i) toxic chemical; (ii) haemostat; or (iii) haemostat in combination with toxic chemical. Several contaminants (VX, petrol and GD) were found to be pro-haemostatic and none had an adverse effect on the rate with which the test products attained haemostasis. However, the total clot strength for blood treated with certain haemostats in the presence of sulphur mustard, soman and petrol was significantly decreased. Three test products failed to demonstrate haemostatic function in this ex vivo (thrombelastography) model; this was tentatively ascribed to the products achieving haemostasis through a tamponade mechanism of action, which can only be replicated using in vivo models. Overall, this study has identified a number of commercial products that may have potential as haemostatic decontaminants and warrant further investigation to establish their decontaminant efficacy.

Ending the use of animals in toxicity testing and risk evaluation.

This article discusses the use of animals for the safety testing of chemicals, including pharmaceuticals, household products, pesticides, and industrial chemicals. It reviews changes in safety testing technology and what those changes mean from the perspective of industrial innovation, public policy and public health, economics, and ethics. It concludes that the continuing use of animals for chemical safety testing should end within the decade as cheaper, quicker, and more predictive technologies are developed and applied.

Achieving One Part Per Billion Hydrogen Sulfide (H2S) Level Detection through Optimizing Composition and Crystallinity of Gold-Decorated Tungsten Trioxide (Au-WO3) Nanofibers.

As a common environmental pollutant and an important breath biomarker for several diseases, it is essential to develop a hydrogen sulfide gas sensor with a low-ppb level detection limit to prevent harmful gas exposure and allow early diagnoses of diseases in low-resource settings. Gold doped/decorated tungsten trioxide (Au-WO3) nanofibers with various compositions and crystallinities were synthesized to optimize H2S-sensing performance. Systematically experimental results demonstrated the ability to detect 1 ppb H2S with a response value (Rair/Rgas) of 2.01 using a 5 at % Au-WO3 nanofibers with average grain sizes of around 15 nm. Additionally, energy barrier difference of sensing materials in air and nitrogen (ΔEb) and power law exponent (n) were determined to be 0.36 eV and 0.7, respectively, at 450 °C indicating that O- is predominately ionic oxygen species and adsorption of O- significantly altered the Schottky barrier between the grain. Such quantitative analysis provides a comprehensive understanding of H2S detection mechanism.

Green Technology Approach Towards the Removal of Heavy Metals, Dyes, and Phenols from Water Using Agro-based Adsorbents: A Review.

The swift pace of socioeconomic development and climatic change have put significant strain on the quality of water resources. While, the bulk availability of agro-based materials arising from nature and agricultural practices has paved the way for researchers in eradicating toxic industrial pollutants such as dyes, heavy-metals, phenolic-compounds, pesticides, etc. by using them as adsorbents. In the area of pollution remediation, inventive technologies have been developing. The adsorption technique stands out among the other wastewater-treatment methods as it is simple, easy, efficient, and cost-effective. The agro-based adsorbents their use in this area contributes to minimizing natural waste. They can be employed in their original raw-form or after undergoing simple processes such as drying, grinding, and carbonization. Moreover, these adsorbents are typically modified physically or chemically to change their surface properties and improve their adsorption efficiency. The low-cost agro adsorbents have shown efficient adsorption capacities towards removing various organic and hazardous water pollutants. With a few exceptions, majority of adsorbents have demonstrated heavy metals, dyes and phenol removal efficiencies exceeding 90%. This review summarizes the available information and strategies for using agro-based adsorbents to eliminate hazardous water pollutants. It is a prospective area for research in the field of environmental pollution.

LC-MS analysis of polar and highly polar organic pollutants in Barcelona urban groundwater using orthogonal LC separation modes.

Groundwater samples may contain thousands of organic pollutants from infiltration of surface water, sewer leakages, and to a minor extent from public water supply network losses. Polar (0 < log D < - 2.0) and very polar substances (log D < - 2.0) have been largely beyond the scope of applied analytical methodologies in environmental monitoring because of challenges related to their extraction from the sample and subsequent chromatographic separation. In this study, we developed an analytical workflow for 96 pollutants covering a broad polarity range, including pharmaceuticals, industrial chemicals, and artificial sweeteners, potentially seeping through the soil in urban areas. The Besos aquifer located at the Northern-eastern edge of the city of Barcelona was chosen as a study area due to the deterioration of the quality of the aquifers over the past years and the proven presence of numerous pollutants. The methodology consisted of vacuum-assisted evaporation (VAE) followed by chromatographic separation of the sample on two columns with orthogonal retention mechanisms, namely, an HSS T3 column (modified C18) and a BEH amide column (HILIC). The analytes were detected by high-resolution mass spectrometry on a Q Exactive Orbitrap system in data-independent acquisition mode. Taking into consideration the retention as well as the peak shape, a Quality Score (QS) was assigned for each analyte to evaluate the quality of each chromatographic peak of each compound. While 67 compounds, including 19 polar and 48 moderately polar, were satisfactorily retained on an HSS T3, 29 compounds, including 14 highly polar, 14 polar, and one moderately polar, were analyzed in the BEH amide column. The optimized methodology was applied for the analysis of 89 out of 96 validated contaminants with satisfactory recoveries in samples collected from seven wells, providing low LODs (0.02 to 0.45 ng L-1) and LOQs (0.06 to 1.34 ng L-1). A number of highly polar and polar compounds not previously reported to occur in GW, including artificial sweeteners, pharmaceuticals, and industrial chemicals, were detected at concentrations as high as few µ g L-1.

Covalent organic frameworks: Pioneering remediation solutions for organic pollutants.

Covalent Organic Frameworks (COFs) have emerged as a promising class of crystalline porous materials with customizable structures, high surface areas, and tunable functionalities. Their unique properties make them attractive candidates for addressing environmental contamination caused by pharmaceuticals, pesticides, industrial chemicals, persistent organic pollutants (POPs), and endocrine disruptors (EDCs). This review article provides a comprehensive overview of recent advancements and applications of COFs in removing and remedying various environmental contaminants. We delve into the synthesis, properties, and performance of COFs and their potential limitations and future prospects.

Structural characterization of 1,3-bis-tert-butyl monocyclic benzene derivatives with agonistic activity towards retinoid X receptor alpha.

Retinoid X receptor alpha (RXRα) plays pivotal roles in multiple biological processes, but limited information is available on the structural features of chemicals that show low affinity for RXRα, but nevertheless cause significant activation, though these may represent a human health hazard. We recently discovered that several industrial chemicals having 1,3-bis-tert-butylbenzene as a common chemical structure exhibit agonistic activity towards rat RXRα. In this study, we explored the structure-activity relationship of 1,3-bis-tert-butyl monocyclic benzene derivatives for RXRα activation by means of in vitro and in silico analyses. The results indicate that a bulky substituent at the 5-position is favorable for agonistic activity towards human RXRα. Since 1,3-bis-tert-butyl monocyclic benzene derivatives with bulky hydrophobic moieties differ structurally from known RXRα ligands such as 9-cis-retinoic acid and bexarotene, our findings may be helpful for the development of structural alerts in the safety evaluation of industrial chemicals for RXRα-based toxicity to living organisms.

A novel benzo hemicyanine-based fluorescent probe for susceptible visualizing detection of phosgene.

Leakage and misuse of phosgene, a common and highly hazardous industrial chemical, have always constituted a safety risk. Therefore, it is crucial to develop sensitive detection methods for gaseous phosgene. This work describes the design and development of a new fluorescent dye based on benzohemicyanine, as well as the synthesis of fluorescent probes for the sensitive detection of gaseous phosgene. Due to the excellent intramolecular charge transfer (ICT) effect from the strong electron-donating impact of the o-aminophenol group on benzo hemicyanine, the probe does not emit fluorescence. When the probe reacts with phosgene, the ICT effect is inhibited, and the result exhibits observable green fluorescence, thereby visualizing the response to phosgene. The probe offers exceptional sensitivity, a rapid response, and a low phosgene detection limit. In addition, we developed probe-loaded, portable test strips for the quick and sensitive detection of phosgene in the gas phase. Finally, the constructed probe-loaded test strips were utilized effectively to monitor the simulated phosgene leakage.

An interactive metabolic map of bio-based chemicals.

Metabolic engineering for the bio-based production of chemicals requires thorough understanding of metabolic reactions including enzymes, cofactors, reactants, and products. Here we present an interactive bio-based chemicals map that visualizes compounds, enzymes, and reaction pathways together with strategies for the production of chemicals by biological, chemical, and combined methods.

Potential of Carbon Nanotube Chemiresistor Array in Detecting Gas-Phase Mixtures of Toxic Chemical Compounds.

Toxic industrial chemicals (TICs), when accidentally released into the workplace or environment, often form a gaseous mixture that complicates detection and mitigation measures. However, most of the existing gas sensors are unsuitable for detecting such mixtures. In this study, we demonstrated the detection and identification of gaseous mixtures of TICs using a chemiresistor array of single-walled carbon nanotubes (SWCNTs). The array consists of three SWCNT chemiresistors coated with different molecular/ionic species, achieving a limit of detection (LOD) of 2.2 ppb for ammonia (NH3), 820 ppb for sulfur dioxide (SO2), and 2.4 ppm for ethylene oxide (EtO). By fitting the concentration-dependent sensor responses to an adsorption isotherm, we extracted parameters that characterize each analyte-coating combination, including the proportionality and equilibrium constants for adsorption. Principal component analysis confirmed that the sensor array detected and identified mixtures of two TIC gases: NH3/SO2, NH3/EtO, and SO2/EtO. Exposing the sensor array to three TIC mixtures with various EtO/SO2 ratios at a fixed NH3 concentration showed an excellent correlation between the sensor response and the mixture composition. Additionally, we proposed concentration ranges within which the sensor array can effectively detect the gaseous mixtures. Being highly sensitive and capable of analyzing both individual and mixed TICs, our gas sensor array has great potential for monitoring the safety and environmental effects of industrial chemical processes.