Chemical Research Articles

Development of a multi-analysis model using an epithelial-fibroblast co-culture system as an alternative to animal testing

The evaluation of respiratory chemical substances has been mostly performed in animal tests (OECD TG 403, TG 412, TG 413, etc.). However, there have been ongoing discussions about the limited use of these inhalation toxicity tests due to differences in the anatomical structure of the respiratory tract, difficulty in exposure, laborious processes, and ethical reasons. Alternative animal testing methods that mimic in vivo testing are required. Therefore, in this study, we established a co-culture system composed of differentiated epithelial cells under an air-liquid interface (ALI) system in the apical part and fibroblasts in the basal part. This system was designed to mimic the wound-healing mechanism in the respiratory system. In addition, we developed a multi-analysis system that simultaneously performs toxicological and functional evaluations. Several individual assays were used sequentially in a multi-analysis model for pulmonary toxicity. Briefly, cytokine analysis, histology, and cilia motility were measured in the apical part, and cell migration and gel contraction assay were performed by exposing MRC-5 cells to the basal culture. First, human airway epithelial cells from bronchial (hAECB) were cultured under air-liquid interface (ALI) system conditions and validated pseudostratified epithelium by detecting differentiation-related epithelial markers using Transepithelial Electrical Resistance (TEER) measurement, Hematoxylin and Eosin (H&E) staining, and immunocytochemistry (ICC) staining. Afterward, the co-culture cells exposed to Transforming growth factor-beta 1 (TGF-β1), a key mediator of pulmonary fibrosis, induced significant toxicological responses such as cytotoxicity, cell migration, and gel contraction, which are wound-healing markers. In addition, cilia motility in epithelial cells was significantly decreased compared to control. Therefore, the multi-analysis model with a 3D epithelial-fibroblast co-culture system is expected to be useful in predicting pulmonary toxicity as a simple and efficient high-throughput screening method and as an alternative to animal testing.

A novel acoustic micro-perforated panel (MPP) based on sugarcane fibers and bagasse

Natural materials are becoming a reliable alternative to traditional artificial materials used in sound absorption insulation. The present study was conducted to investigate the acoustic insulation of micro-perforated panel (MPP) based on sugarcane fibers and bagasse as an available and environmentally friendly material. The absorption properties of single- and double-leaf natural micro-perforated panels (MPP) made of bagasse and also nonnatural MPPs made of Plexiglass were measured using an impedance tube based on ISO 10534–2. Then the effect of bagasse and sugarcane fibers composite on the air gap of MPP was investigated. The results showed the peak sound absorption of the bagasse composite is in the range of 1000 to 2000 Hz, and the sugarcane fiber composite has a higher sound absorption coefficient than the bagasse composite. Also, natural MPPs have a higher absorption coefficient than nonnatural MPPs at all frequencies, and as the panel thickness increases, the peak absorption coefficient shifts to lower frequencies. The peak sound absorption coefficient of double-leaf MPPs made of bagasse is 76%, in the range of 160 to 200 Hz. Using sugarcane fiber composite in the air gap of single- and double-leaf natural MPPs causes the absorption peak to shift to frequencies below 100 Hz. According to the results, natural MPPs have a high sound absorption coefficient at low frequencies. These panels can control sounds with much lower frequencies, especially in a double layer and along with cane fiber composite in their air gap.

Re-evaluation of the reduced heart weights in male rats in a 28-day oral repeated-dose toxicity study of tetramethylammonium hydroxide

We recently conducted a detailed hazard assessment of tetramethylammonium hydroxide (TMAH), a priority chemical substance under the Japan Chemical Substances Control Law. During this assessment, there was debate regarding the reduced heart weight observed in the treated male groups in the 28-day rat oral repeated-dose toxicity study. This finding was not observed in females in this study and in both sexes of oral toxicity studies for tetramethylammonium chloride (TMAC) or tetramethylammonium hydrogen phthalate (TMAHP). Unpublished individual data from the oral TMAH developmental and reproductive toxicity (DART) screening study were also obtained; no effect on heart weight was observed. In addition, background data on rat heart weight from six 28-day oral toxicity studies conducted in the same facility, year, strain, age, and breeder as the TMAH study were obtained from the Japan Existing Chemical Substances Database (JECDB). These investigations suggest that the statistically significant lower heart weight in the treated males in the 28-day toxicity study is likely caused by an incidental skewing of individuals with heavier heart weights toward control male groups and is not due to TMAH treatment. Thus, it is worthwhile to include as much relevant data as possible to confirm or refute unexpected findings in toxicity studies.

Investigation of the effect of human intestinal microbiota bacteria on the bioremediation of commonly used pesticides by liquid chromatography

Pesticides are defined as chemical substances used to protect a variety of plants from parasite infestation. Due to their chemical structure, they have a long half-life and the capacity to form residues, and therefore many fruits can contain pesticide residues. Pesticide exposure may occur via inhalation, ingestion, or direct contact. The European Commission's directive restricts the use of pesticides and sets a residue limit of 0.1 μg/L. The aim of this study is to determine the impact of bacteria in the human gut microbiota on the biodegradation of commonly used pesticides. This study investigated the effects of five bacterial strains, namely Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae (K. pneumoniae), and Enterococcus faecalis (E. faecalis), isolated from neonatal rectal swab samples and, blood samples on the degradation of pesticides using liquid chromatography and mass spectrometry. (LC-MS). All bacteria resulted in significant pesticide degradation (p < 0.05). E. faecalis caused significantly more degradation than K. pneumoniae (p = 0.043). No significant difference was observed between the degradation rates of pesticides and other bacteria (p > 0.05). The results demonstrate that bacteria can be used to clean water and soil contaminated with pesticides. Therefore, we do not have information about possible mutations in DNA. This is the biggest limitation of this study. Therefore, our study data needs to be supported with study data including more strains and examining bacterial DNA with new generation sequencing methods.

Exploring Water-Soluble South African Tulbaghia violacea Harv Extract as a Therapeutic Approach for Triple-Negative Breast Cancer Metastasis.

Triple-negative breast cancer (TNBC) accounts for approximately 20% of all breast cancer cases and is characterized by a lack of estrogen, progesterone, and human epidermal growth factor 2 receptors. Current targeted medicines have been unsuccessful due to this absence of hormone receptors. This study explored the efficacy of Tulbaghia violacea, a South African medicinal plant, for the treatment of TNBC metastasis. Extracts from T. violacea leaves were prepared using water and methanol. However, only the water-soluble extract showed anti-cancer activity and the effects of this water-soluble extract on cell adhesion, invasion, and migration, and its antioxidant activity were assessed using MCF-10A and MDA-MB-231 cells. The T. violacea extract that was soluble in water effectively decreased the movement and penetration of MDA-MB-231 cells through the basement membrane in scratch and invasion tests, while enhancing their attachment to a substance resembling an extracellular matrix. The sample showed mild-to-low antioxidant activity in the antioxidant assy. Nuclear magnetic resonance spectroscopy revealed 61 chemical components in the water-soluble extract, including DDMP, 1,2,4-triazine-3,5(2H,4H)-dione, vanillin, schisandrin, taurolidine, and α-pinene, which are known to have anti-cancer properties. An in-depth examination of the transcriptome showed alterations in genes linked to angiogenesis, metastasis, and proliferation post-treatment, with reduced activity in growth receptor signaling, angiogenesis, and cancer-related pathways, such as the Wnt, Notch, and PI3K pathways. These results indicate that T. violacea may be a beneficial source of lead chemicals for the development of potential therapeutic medicines that target TNBC metastasis. Additional studies are required to identify the precise bioactive chemical components responsible for the observed anti-cancer effects.

Kinetic study and modelling of drying of Chlorellavulgaris

Microalgae, a versatile source of biofuels, chemicals, and nutraceuticals, necessitates efficient drying for subsequent applications. Extensive studies have been done on the benefits and uses of microalgae, but very few are focusing on drying. This research focused on a specific microalga, Chlorella vulgaris, to analyze the drying kinetics involved in the moisture removal process. Data on drying behavior were collected using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). As the temperature rose, the moisture content of the biomass rapidly decreased and peaked between 65 and 80 °C. From four widely used drying kinetics models, which are typically used to analyze the drying kinetics of agricultural goods, four non-isothermal drying models were derived. These models were assessed using the coefficient of determination (R2) and reduced chi-square (χ2). Page's model emerged as the best fit for describing drying kinetics. This study introduces a novel approach to characterize the intrinsic properties of freshly harvested Chlorella vulgaris by employing TGA and DSC. Unlike other studies focusing on conventional drying methods, our investigation provides real-time insights into the microalgae's thermal behavior during drying.

Dermatoses among athletes

Introduction: Dermatoses are a common problem among athletes due to exposure to various chemical substances, close skin contact with other individuals and higher risk of abrasions and skin trauma. Dermatoses affecting athletes may be divided to inflammatory, infectious and mechanical dermatoses. Due to various presentations, athletes should not neglect any lesions on their skin and should seek medical help. Physicians must remember about thorough examination including skin, to check if athletes can exercise and participate in sport events. Purpose of work: The aim of this article is to emphasize the association between dermatoses and sport activities, including the necessity of their proper diagnosis and treatment. Materials and methods: Articles in Pubmed database were researched using following keywords: dermatoses among athletes, sport dermatoses, infections among athletes, exercise-induced anaphylaxis. Conclusions: Skin diseases may affect athletes’ performance and require them to cease professional training and close contact with other athletes. Physicians must remember the necessity of an accurate diagnosis and prompt initiation of the treatment to avoid delay in practice, team training and competitions.

Fracturing Processes in Specimens with Internal vs. Throughgoing Flaws: An Experimental Study Using 3D Printed Materials

AbstractThe fracturing behavior and associated mechanical characterization of rocks are important for many applications in the fields of civil, mining, geothermal, and petroleum engineering. Laboratory testing of rocks plays a major role in understanding the underlying processes that occur on the larger scale and for predicting rock behavior. Fracturing research requires well-defined and consistent boundary conditions. Consequently, the testing design and setup can greatly influence the results. In this study, a comprehensive experimental program using an artificial material was carried out to systematically evaluate the effects of different parameters in rock testing under uniaxial compression. The parameters include compression platen type, specimen centering, loading control method, boundary constraints, and flaw parameters. The results show that these testing conditions have a significant effect on the mechanical behavior of rocks. Using a fixed compression platen helped reduce bulging of the material. Centering of the specimen played a critical role to avoid buckling and unequal distribution of stress. Slower displacement rates can control the energy being released once failure occurs to prevent the specimen from exploding. Also, the frictional end effects were investigated by comparing friction-reduced and non-friction-reduced end conditions. Very importantly, the study also identified variations in crack initiation and propagation between specimens with internal flaws and specimens with throughgoing flaws. This investigation showed that wing cracks appeared in specimens with throughgoing flaws, while wing cracks with petal cracks were associated with the internal flaws. It also showed that the mechanical properties are influenced by the inclination of the flaws and established that specimens with internal flaws generally exhibit higher strength compared to specimens with throughgoing flaws. The systematic analysis presented in this work sheds light on important considerations that need to be taken into account when conducting fracture research and adds knowledge to the fundamental understanding of how fractures occur in nature.

Outstanding Scientist I. Ya. Horbachevsky (dedicated to the 170th birth anniversary)

Ivan Yakovych Horbachevsky is one of the outstanding scientists of world science, whose activities span the middle of the 20th century. He, our compatriot, comes from the village Zarubyntsi, Ternopil region. The numerous scientific and governmental titles, ranks and awards that he was awarded confirm Ivan Horbachevsky’s global authority and popularity. He was elected honorary president of international scientific forums and congresses. He was also entrusted with the most difficult tasks in medicine and education. The scientist brought recognition to University of Vienna. He was elected a member (and later chairman) of the Royal Sanitary Council, given several high titles and appointed the first minister of health in Austria-Hungary. Ivan Horbachevsky’s scientific heritage includes more than 50 works published in German, Czech and Ukrainian languages (only 6 of them were in Ukrainian). He proposed the nomenclature of organic (1924–1926) and inorganic compounds (1939–1941), which formed the basis of the chemical substance classification and nomenclature. His nomenclature was implemented in Ukraine before World War II. Ivan Yakovych Horbachevsky was a candidate for the Nobel Prize in Physiology and Medicine in 1911. He lived for 67 years outside of his motherland, but he was closely connected with Ukraine, and did a lot for our state independence.

Influence of Academic Training and Professional Experience on the Management of Deep Caries Lesions.

Managing caries lesions that affect the inner third of the dentin is crucial to ensuring pulp vitality; the clinician must make decisions that will affect the vitality of the tooth. Our purpose is to understand the behavior of Spanish dentists in treating deep cavities and to examine whether variations exist based on their academic training and/or years of professional experience. This study was approved by the ethics committee of the Balearic Islands CEI-IB. A survey was conducted using the SurveyMonkey platform with 11 questions, the first 4 of which focused on defining the characteristics of the respondents. The following six concerned a clinical case of deep caries in tooth number 4.7, and the last regarded the opinion of the actual treatment of the case. The survey was sent by email in April 2022. The results were analyzed with the SPSS 29.0 program using the chi-square test. A total of 347 responses were obtained (93.95%), and those surveyed stated that they apply minimal intervention concepts in their treatments, with 90.49% performing conservative dentistry treatments daily. A total of 56.48% of the respondents had bachelor's degrees, 12.39% had graduated, 33.14% had a postgraduate degree, 38.90% had a master's degree, and 17% had a doctorate. Most (40.63%) had been in professional practice for 16-30 years. Significant differences were identified regarding years of professional experience in terms of decision-making in methods of treatment and the choice of materials used for pulp protection. Likewise, significant differences were found regarding the academic training of the respondents, the cavity cleaning method selected, and the use of chemical substances for removing carious dentin. We can conclude that academic training and years of professional practice influence decision-making at some points in treating deep caries lesions.

Cross-Linking Agents in Three-Component Materials Dedicated to Biomedical Applications: A Review.

In biomaterials research, using one or two components to prepare materials is common. However, there is a growing interest in developing materials composed of three components, as these can offer enhanced physicochemical properties compared to those consisting of one or two components. The introduction of a third component can significantly improve the mechanical strength, biocompatibility, and functionality of the resulting materials. Cross-linking is often employed to further enhance these properties, with chemical cross-linking agents being the most widely used method. This article provides an overview of the chemical agents utilized in the cross-linking of three-component biomaterials. The literature review focused on cases where the material was composed of three components and a chemical substance was employed as the cross-linking agent. The most commonly used cross-linking agents identified in the literature include glyoxal, glutaraldehyde, dialdehyde starch, dialdehyde chitosan, and the EDC/NHS mixture. Additionally, the review briefly discusses materials cross-linked with the MES/EDC mixture, caffeic acid, tannic acid, and genipin. Through a critical analysis of current research, this work aims to guide the development of more effective and safer biopolymeric materials tailored for biomedical applications, highlighting potential areas for further investigation and optimization.

Super‐Strong, Super‐Stiff, and Super‐Tough Fluorescent Alginate Fibers with Outstanding Tolerance to Extreme Conditions

AbstractThe combination of multiple physical properties is of great importance for widening the application scenarios of biomaterials. It remains a great challenge to fabricate biomolecules‐based fibers gaining both mechanical strength and toughness which are comparable to natural spider dragline silks. Here, by mimicking the structure of dragline silks, a high‐performance fluorescent fiber Alg‐TPEA‐PEG is designed by non‐covalently cross‐linking the polysaccharide chains of alginate with AIEgen‐based surfactant molecules as the flexible contact points. The non‐covalent cross‐linking network provides sufficient energy‐dissipating slippage between polysaccharide chains, leading to Alg‐TPEA‐PEG with highly improved mechanical performances from the plastic strain stage. By successfully transferring the extraordinary mechanical performances of polysaccharide chains to macroscopic fibers, Alg‐TPEA‐PEG exhibits an outstanding breaking strength of 1.27 GPa, Young's modulus of 34.13 GPa, and toughness of 150.48 MJ m−3, which are comparable to those of dragline silk and outperforming other artificial materials. More importantly, both fluorescent and mechanical properties of Alg‐TPEA‐PEG can be well preserved under various harsh conditions, and the fluorescence and biocompatibility facilitate its biological and biomedical applications. This study affords a new biomimetic designing strategy for gaining super‐strong, super‐stiff, and super‐tough fluorescent biomaterials.

An alternative to petrochemicals: biomass electrovalorization.

Replacing petrochemicals with refined waste biomass as a sustainable chemical source has become an attractive option to lower global carbon emissions. Popular methods of refining lignocellulosic waste biomass use thermochemical processes, which have significant environmental downsides. Using electrochemistry instead would overcome many of these downsides, directly driving chemical reactions with renewable electricity and revolutionizing the way many chemicals are produced today. This review mainly focuses on two furanic platform chemicals that are produced from the dehydration of cellulose, 5-hydroxymethylfurfural and furfural, which can be electrochemically reduced or oxidized to replace fuels and monomers that today are obtained from petrochemicals. Critical parameters such as electrode materials and electrolyte pH are discussed in relation to their influence on conversion efficiency and product distribution.This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'.

Systems pharmacology-based drug discovery from Amaryllidaceae alkaloids and investigation of mechanisms of action in treatment of Alzheimer’s disease

Abstract Objectives Given the success of galanthamine in treating Alzheimer’s disease, this study aims to establish an effective method to find drugs from Amaryllidaceae alkaloids and to clarify its mechanism in treating Alzheimer’s disease. Methods The pharmacodynamic basis and mechanism of action between Amaryllidaceae alkaloids and Alzheimer’s disease were explored by constructing a compound-target-disease network, targets protein-protein interaction, gene ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, and molecular docking verification. Key findings In total, a chemical library of 357 potential alkaloids was constructed. A total of 100 active alkaloid components were identified. Thirty-nine associated targets were yielded based on network construction, and the key targets were defined as HSP90AA1, ESR1, NOS3, PTGS2, and PPARG using protein–protein interaction network. Gene ontology items (490) and 68 Kyoto Encyclopedia of Genes and Genomes pathways were selected through the enrichment of target functions, including neuroactive ligand–receptor interaction, calcium signaling pathway, cAMP signaling pathway, Alzheimer disease, and serotonergic synapse that were related to Alzheimer’s disease. Lastly, molecular docking demonstrated good stability in combining selected alkaloids with targets. Conclusions This study explained the mechanisms of Amaryllidaceae alkaloids in preventing and treating Alzheimer’s disease and established a novel strategy to discover new drugs from biological chemical sources.

Dissolved and particulate phase phthalic acid esters in urban, suburban, and rural riverine catchments along the southeast coast of India after the COVID-19 pandemic

Dumped waste plastics have been evidenced as a potential source for harmful chemicals along the riverine regions of India. Furthermore, Corona Virus Disease – 19 (COVID-19) pandemic resulted in a subsequent surge in the use of personal protective equipment (PPE) related single-use plastics and Tamil Nadu was India's second major waste generator. Given the newer challenges from dumped waste plastics along the four major rivers of Tamil Nadu emptying into the Bay of Bengal, we investigated thirteen phthalic acid esters (PAEs), in both dissolved and particulate phases of river water and drinking water samples. Ʃ13PAEs in both phases followed the urban > suburban > rural catchment trend. Di (2-ethyl hexyl) phthalate (DEHP) was ubiquitous in both phases and the sites having a prevalence of open burning activities in the urban catchment showed elevated levels. The suburban and rural catchments of the Kaveri River (KR) and Thamirabharani River (TR) were predominated by DEP and DEHP. It is noteworthy that in the urban catchment, Ln (DiBP) and dissolved organic carbon (Ln DOC), were strongly correlated (R2 = 0.894, p < 0.05). Furthermore, a significant increase of DiBP (p < 0.05) in the urban catchment after the second phase of the pandemic most likely resulted from the wide use of DiBP in PPE plastics. Community-stored water from urban catchment was found to have a maximum of ∑13PAEs up to 3769.38 ng/L in the dissolved phase with elevated DMP concentrations leading to higher estrogenic equivalent. The average daily intake for dissolved phase PAEs was below the USEPA-recommended limit for drinking water. However, prolonged exposure to heavier PAEs in particulate matter cannot be ignored. Estimated ecotoxicological risk assessment showed the highest risk for fish species due to DEHP.

Zakłady niesevesowskie – stwarzające zagrożenie wystąpienia poważnej awarii przemysłowej

Non-Seveso establishments – plants posing a risk of a major industrial accident Various definitions and approaches used by organizations and control and supervisory institutions are reflected in the list of establishments posing a risk of a major industrial accident, which are not upper- and lower-tier establishments. The article proposes a definition that includes both sub-threshold establishments with smaller quantities of non-hazardous substances than qualify an establishment as a lower tier establishment and establishments containing other chemical substances that could be the source of a major accident. The results of analyses of databases of chemical substances present in non-Seveso establishments, the correlation of the definition of a major accident and chemical substances, and the failure rate for non-Seveso establishments are presented. Keywords: non-Seveso establishments, dangerous substances, major accidents

NOISE-RELATED HEARING LOSS FREQUENCY AND RELATED FACTORS IN A UNIVERSITY HOSPITAL OCCUPATIONAL DISEASES CLINIC. Ege University Faculty of Medicine Hospital Occupational Diseases Clinic -2018

Objective: Noise is an important hazard that negatively affects hearing and perception in humans, causes physiological and psychological disorders, and reduces work performance. We wanted to determine the socio-demographic and occupational factors associated with the frequency of noise-induced hearing loss in patients who applied to the occupational diseases clinic and draw attention to what should be done to prevent its occurrence. Methods: The population of the cross-sectional study consisted of 463 workers who applied to a university hospital Occupational Diseases Policlinic between November 2015 and November 2018. General physical examination was performed and hearing problems were evaluated and than audiometric examination was performed with Madsen Itera II audiometry device. Chi-square test and descriptive statistics were used as statistical analysis. Results: 23.5% of the workers were diagnosed with hearing loss. 397 (85.7%) of the participants described that they were exposed to noise in the workplace. Noise exposure has been associated with hearing loss. 15 packs / year and above smoking, expressing noise exposure in the workplace and not using headphones, chemical substances in the work environment; Exposure to any of the lead, manganese and mercury made a significant difference in terms of hearing loss. Conclusion: The correct use of personal protective equipment such as earphones depends on individual factors. Incorrect and inadequate headphone use is an important factor in noise-induced hearing loss. For this reason, engineering measures are extremely important among the primary preventive methods. Smoking, chemical exposure are effective factors in noise-related hearing loss.

High-Volume Production of Repeatable High Enhancement SERS Substrates Using Solid-State Superionic Stamping

Abstract Surface-enhanced Raman spectroscopy (SERS) is emerging as a powerful tool for detecting and identifying chemical and biological substances because of its high sensitivity, specificity, speed, and label-free detection. For SERS substrates to be effective in sensing applications, they must exhibit reproducible and robust high signal enhancement and cost-effective scalability. This article introduces a highly sensitive, large-area silver SERS substrate patterned with a uniform array of 3D retroreflecting inverted pyramids and develops a manufacturing pathway for it, using a novel and facile electrochemical imprinting process called solid-state superionic stamping (S4). Substrates, approximately 4 mm2 in area, are produced and tested with 1,2-bis(4-pyridyl) ethylene (BPE). Uniformly high and reproducible spatially averaged enhancement factor (EF), typically around a value of 2 × 107 with a relative standard deviation of 6.7% and a high batch-to-batch repeatability with a relative standard deviation of 10.5% between batches were observed. Passivating a substrate's surface with atomically thin layers of alumina, deposited using atomic layer deposition (ALD) was effective in maintaining the EF constant over a 60-day period, albeit with a trade-off between its EF and its lifespan. S4 has the potential to make substrates with EF consistently greater than 107 available at a cost of $1 to $2 per substrate, allowing SERS to be adopted across a wide spectrum of high-volume applications, including security, food safety, medical diagnostics, and chem-bio analysis.

Emissions of Semi-Volatile Organic Compounds from Architectural Coatings and Polyvinyl Chloride Floorings: Microchamber Method.

Semi-volatile organic compounds (SVOCs) are modern chemical substances that are present in large quantities in indoor environments. Understanding the emission of SVOCs from building materials is essential to identify the main sources of indoor SVOCs and to improve indoor air quality. In this study, a reference method employing custom-designed microchambers (630 mL) was optimized by improving the structure of the gas path and adding polytetrafluoroethylene inner coating to the chamber. After optimization, the recoveries of the microchamber method were significantly improved (75.4-96.7%), and the background in the microchamber was greatly reduced (<0.02 μg/h). By using the microchamber method, 33 SVOCs (including two alkanes, one aromatic, one nitrogen compound, and twenty-nine oxygenated compounds) and 32 SVOCs (including seven alkanes, eight aromatics, and seventeen oxygenated compounds) were detected in the emissions of the architectural coating and the PVC flooring samples, respectively. The area-specific emission rates (SERa) of total SVOCs emitted from architectural coatings and PVC floorings were in the range of 4.09-1309 μg/m2/h) (median: 10.3 μg/m2/h) and 0.508-345 μg/m2/h (median: 11.9 μg/m2/h), respectively. Propanoic acid had the highest SERa (3143 μg/m2/h) in architectural coatings, while methylbenzene (345 μg/m2/h), 2-methylnaphthalene (65.2 μg/m2/h), and naphthalene (60.3 μg/m2/h) were main SVOCs emitted from PVC floorings. Meanwhile, the average second-stage (adsorbed phase) emission mass of the total SVOCs accounts for 66.3% and 47.3% in architectural coatings and PVC floorings, respectively, suggesting that the SVOCs emitted from building materials have a strong tendency to be absorbed on the surface of the room, e.g., the interior wall, the desk or even the skin.

Determining Marine Biodegradation Kinetics of Chemicals Discharged from Offshore Oil Platforms─Whole Mixture Testing at High Dilutions Increases Environmental Relevance.

Offshore oil platforms discharge enormous volumes of produced water that contain mixtures of petrochemicals and production chemicals. It is crucial to avoid the discharge of particularly those chemicals that are persistent in the marine environment. This study aims to (1) develop a biodegradation testing approach for discharged chemicals by native marine microorganism, (2) determine how dilution affects biodegradation, and (3) determine biodegradation kinetics for many discharged chemicals at low and noninhibitory concentrations. Produced water from an offshore oil platform was diluted in the ratio of 1:20, 1:60, and 1:200 in seawater from the same location and incubated for 60 days at 10 °C. Automated solid-phase microextraction GC-MS was used as a sensitive analytical technique, and chemical-specific primary degradation was determined based on peak area ratios between biotic test systems and abiotic controls. Biodegradation was inhibited at lower dilutions, consistent with ecotoxicity tests. Biodegradation kinetics were determined at the highest dilution for 139 chemicals (43 tentatively identified), and 6 chemicals were found persistent (half-life >60 days). Nontargeted analysis by liquid chromatography-high-resolution MS was demonstrated as a proof-of-principle for a comprehensive assessment. Biodegradation testing of chemicals in discharges provides the possibility to assess hundreds of chemicals at once and find the persistent ones.