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International Journal of Molecular... Jun 2023A [3 + 2] cycloaddition reaction using dialkyne and diazide comonomers, both bearing explosophoric groups, to synthesize energetic polymers containing furazan and...
A [3 + 2] cycloaddition reaction using dialkyne and diazide comonomers, both bearing explosophoric groups, to synthesize energetic polymers containing furazan and 1,2,3-triazole ring as well as nitramine group in the polymer chain have been described. The developed solvent- and catalyst-free approach is methodologically simple and effective, the comonomers used are easily available, and the resulting polymer does not need any purification. All this makes it a promising tool for the synthesis of energetic polymers. The protocol was utilized to generate multigram quantities of the target polymer, which has been comprehensively investigated. The resulting polymer was fully characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers, thermochemical characteristics, and combustion features indicate the prospects of this polymer as a binder base for energetic materials. The polymer of this study surpasses the benchmark energetic polymer, nitrocellulose (NC), in a number of properties.
Topics: Polymers; Triazoles; Plasticizers; Aniline Compounds
PubMed: 37298596
DOI: 10.3390/ijms24119645 -
Journal of Exposure Science &... Jan 2022Existing models for estimating children's exposure to chemicals through mouthing currently depends on the availability of chemical- and material-specific experimental...
BACKGROUND
Existing models for estimating children's exposure to chemicals through mouthing currently depends on the availability of chemical- and material-specific experimental migration rates, only covering a few dozen chemicals.
OBJECTIVE
This study objective is hence to develop a mouthing exposure model to predict migration into saliva, mouthing exposure, and related health risk from a wide range of chemical-material combinations in children's products.
METHODS
We collected experimental data on chemical migration from different products into saliva for multiple substance groups and materials, identifying chemical concentration and diffusion coefficient as main properties of influence. To predict migration rates into saliva, we adapted a previously developed migration model for chemicals in food packaging materials. We also developed a regression model based on identified chemical and material properties.
RESULTS
Our migration predictions correlate well with experimental data (R = 0.85) and vary widely from 8 × 10 to 32.7 µg/10 cm/min, with plasticizers in PVC showing the highest values. Related mouthing exposure doses vary across chemicals and materials from a median of 0.005 to 253 µg/kg/d. Finally, we combined exposure estimates with toxicity information to yield hazard quotients and identify chemicals of concern for average and upper bound mouthing behavior scenarios.
SIGNIFICANCE
The proposed model can be applied for predicting migration rates for hundreds of chemical-material combinations to support high-throughput screening.
Topics: Child; Environmental Exposure; Food Packaging; Humans; Plasticizers; Saliva
PubMed: 34188178
DOI: 10.1038/s41370-021-00354-0 -
Environmental Research Nov 2022Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by...
Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP), were quantified in bivalves, fish, and holothurians collected from a coastal pristine area at the western Mediterranean Sea. MP ingestion in sediment-feeders holothurians (mean value 12.67 ± 7.31 MPs/individual) was statistically higher than ingestion in bivalves and fish (mean 4.83 ± 5.35 and 3 ± 4.44 MPs/individual, respectively). The main ingested polymers were polyethylene, polypropylene, and polystyrene. The levels of BPS, BPF, and DEHP were highest in bivalves' soft tissue; BPA and DBP had the highest levels in the holothurians' muscle. In addition, the levels of all plasticizers assessed were lowest in fish muscle; only BPA levels in fish were higher than in bivalves, with intermediate values between those of bivalves and holothurians. This study provides data on exposure to MPs and plasticizers of different species inhabiting Cabrera Marine Protected Area (MPA) and highlights the differences in MP ingestion and levels of plasticizers between species with different ecological characteristics and feeding strategies.
Topics: Animals; Benzhydryl Compounds; Bivalvia; Dibutyl Phthalate; Diethylhexyl Phthalate; Eating; Fishes; Microplastics; Phenols; Phthalic Acids; Plasticizers; Plastics
PubMed: 35948144
DOI: 10.1016/j.envres.2022.114034 -
Journal of Exposure Science &... Mar 2023Many phthalates are environmental pollutants and toxic to humans. Following phthalate regulations, human exposure to phthalates has globally decreased with time in...
BACKGROUND
Many phthalates are environmental pollutants and toxic to humans. Following phthalate regulations, human exposure to phthalates has globally decreased with time in European countries, the US and Korea. Conversely, exposure to their substitutes DEHT and/or DINCH has increased. In other countries, including China, little is known on the time-trends in human exposure to these plasticizers.
OBJECTIVE
We aimed to estimate time-trends in the urinary concentrations of phthalates, DEHT, and DINCH metabolites, in general population from non-European countries, in the last decade.
METHODS
We compiled human biomonitoring (HBM) data from 123 studies worldwide in a database termed "PhthaLit". We analyzed time-trends in the urinary concentrations of the excreted metabolites of various phthalates as well as DEHT and DINCH per metabolite, age group, and country/region, in 2009-2019. Additionally, we compared urinary metabolites levels between continents.
RESULTS
We found solid time-trends in adults and/or children from the US, Canada, China and Taiwan. DEHP metabolites decreased in the US and Canada. Conversely in Asia, 5oxo- and 5OH-MEHP (DEHP metabolites) increased in Chinese children. For low-weight phthalates, the trends showed a mixed picture between metabolites and countries. Notably, MnBP (a DnBP metabolite) increased in China. The phthalate substitutes DEHT and DINCH markedly increased in the US.
SIGNIFICANCE
We addressed the major question of time-trends in human exposure to phthalates and their substitutes and compared the results in different countries worldwide.
IMPACT
Phthalates account for more than 50% of the plasticizer world market. Because of their toxicity, some phthalates have been regulated. In turn, the consumption of non-phthalate substitutes, such as DEHT and DINCH, is growing. Currently, phthalates and their substitutes show high detection percentages in human urine. Concerning time-trends, several studies, mainly in Europe, show a global decrease in phthalate exposure, and an increase in the exposure to phthalate substitutes in the last decade. In this study, we address the important question of time-trends in human exposure to phthalates and their substitutes and compare the results in different countries worldwide.
Topics: Adult; Child; Humans; Diethylhexyl Phthalate; Phthalic Acids; Environmental Pollutants; Plasticizers; North America; Environmental Exposure
PubMed: 35513587
DOI: 10.1038/s41370-022-00441-w -
Basic & Clinical Pharmacology &... Sep 2017Phthalates are known endocrine disruptors. Not commonly recognized, phthalates are used as excipients in a number of drug formulations. We aimed to describe the sale of... (Comparative Study)
Comparative Study
Phthalates are known endocrine disruptors. Not commonly recognized, phthalates are used as excipients in a number of drug formulations. We aimed to describe the sale of phthalate-containing drugs in Denmark from 2004 to 2015. National data on annual sale of medications (tablets only) were accessed from medstat.dk. Data from the Danish Medicines Agency on phthalate content per tablet were merged with data on total sale for each active substance and drug formulation. We used the 'defined daily dose' (DDD) as the unit of sale and calculated the total amount of phthalate (mg) dispensed per 1000 inhabitants. Specific tablet content was compared with the maximum daily exposure limits defined by regulatory agencies for diethyl phthalate (DEP) and dibutyl phthalate (DBP) of 4.0 and 0.01 mg/kg/day, respectively. Use of phthalate-containing drugs in Denmark was common. We found 154 drug products containing five different phthalates. Two low-molecular-weight phthalates and three high-molecular-weight phthalates were identified, with a total sale of 59.4 and 112 DDD per 1000 inhabitants per day during the study period, respectively. The highest amount of DBP was found in multi-enzymes (24.6-32.8 mg per DDD) and mesalazine (12.5-26.4 mg per DDD). Budesonide, lithium and bisacodyl also exceeded the DBP exposure limit of 0.01 mg/kg/day. Other drugs had high levels of DEP, although not exceeding the exposure limit. Sales of phthalate-containing drugs in Denmark from 2004 to 2015 were substantial, and phthalate exposure from several products exceeded the regulatory exposure limit introduced in 2014.
Topics: Adult; Databases, Factual; Denmark; Dibutyl Phthalate; Drug Contamination; Endocrine Disruptors; Environmental Exposure; Excipients; Humans; Legislation, Drug; Molecular Weight; Pharmaceutical Preparations; Phthalic Acids; Plasticizers; Tablets
PubMed: 28371296
DOI: 10.1111/bcpt.12781 -
Environmental Science and Pollution... Jul 2013Emerging contaminants in wastewater and sewage sludge spread on agricultural soil can be transferred to the human food web directly by uptake into food crops or...
Emerging contaminants in wastewater and sewage sludge spread on agricultural soil can be transferred to the human food web directly by uptake into food crops or indirectly following uptake into forage crops. This study determined uptake and translocation of the organophosphates tris(1-chloro-2-propyl) phosphate (TCPP) (log Kow 2.59), triethyl-chloro-phosphate (TCEP) (log Kow 1.44), tributyl phosphate (TBP) (log Kow 4.0), the insect repellent N,N-diethyl toluamide (DEET) (log Kow 2.18) and the plasticiser N-butyl benzenesulfonamide (NBBS) (log Kow 2.31) in barley, wheat, oilseed rape, meadow fescue and four cultivars of carrot. All species were grown in pots of agricultural soil, freshly amended contaminants in the range of 0.6-1.0 mg/kg dry weight, in the greenhouse. The bioconcentration factors for root (RCF), leaf (LCF) and seed (SCF) were calculated as plant concentration in root, leaf or seed over measured initial soil concentration, both in dry weight. The chlorinated flame retardants (TCEP and TCPP) displayed the highest bioconcentration factors for leaf and seed but did not show the same pattern for all crop species tested. For TCEP, which has been phased out due to toxicity but is still found in sewage sludge and wastewater, LCF was 3.9 in meadow fescue and 42.3 in carrot. For TCPP, which has replaced TCEP in many products and also occurs in higher residual levels in sewage sludge and wastewater, LCF was high for meadow fescue and carrot (25.9 and 17.5, respectively). For the four cultivars of carrot tested, the RCF range for TCPP and TCEP was 10-20 and 1.7-4.6, respectively. TCPP was detected in all three types of seeds tested (SCF, 0.015-0.110). Despite that DEET and NBBS have log Kow in same range as TCPP and TCEP, generally lower bioconcentration factors were measured. Based on the high translocation of TCPP and TCEP to leaves, especially TCPP, into meadow fescue (a forage crop for livestock animals), ongoing risk assessments should be conducted to investigate the potential effects of these compounds in the food web.
Topics: Animal Feed; Crops, Agricultural; DEET; Daucus carota; Environmental Monitoring; Flame Retardants; Food Chain; Food Contamination; Hordeum; Organophosphates; Plant Roots; Plasticizers; Risk Assessment; Seeds; Sewage; Soil; Soil Pollutants; Sulfonamides; Triticum
PubMed: 23250727
DOI: 10.1007/s11356-012-1363-5 -
Environmental Pollution (Barking, Essex... Nov 2022Human exposure to organic contaminants is widespread. Many of these contaminants show adverse health effects on human population. Human biomonitoring (HBM) follows the...
Human exposure to organic contaminants is widespread. Many of these contaminants show adverse health effects on human population. Human biomonitoring (HBM) follows the levels and the distribution of biomarkers of exposure (BoE), but it is usually done in a targeted manner. Suspect and non-targeted screening (SS/NTS) tend to find BoE in an agnostic way, without preselection of compounds, and include finding evidence of exposure to predicted, unpredicted known and unknown chemicals. This study describes the application of high-resolution mass spectrometry (HRMS)-based SS/NTS workflow for revealing organic contaminants in urine of a cohort of 200 children from Slovenia, aged 6-9 years. The children originated from two regions, urban and rural, and the latter were sampled in two time periods, summer and winter. We tentatively identified 74 BoE at the confidence levels of 2 and 3. These BoE belong to several classes of pharmaceuticals, personal care products, plasticizers and plastic related products, volatile organic compounds, nicotine, caffeine and pesticides. The risk of three pesticides, atrazine, amitraz and diazinon is of particular concern since their use was limited in the EU. Among BoE we tentatively identified compounds that have not yet been monitored in HBM schemes and demonstrate limited exposure data, such as bisphenol G, polyethylene glycols and their ethers. Furthermore, 7 compounds with unknown use and sources of exposure were tentatively identified, either indicating the entry of new chemicals into the market, or their metabolites and transformation products. Interestingly, several BoE showed location and time dependency. Globally, this study presents high-throughput approach to SS/NTS for HBM. The results shed a light on the exposure of Slovenian children and raise questions on potential adverse health effects of such mixtures on this vulnerable population.
Topics: Atrazine; Biological Monitoring; Biomarkers; Caffeine; Child; Diazinon; Environmental Exposure; Environmental Monitoring; Ethers; Humans; Nicotine; Pesticides; Pharmaceutical Preparations; Plasticizers; Plastics; Polyethylene Glycols; Volatile Organic Compounds
PubMed: 36064054
DOI: 10.1016/j.envpol.2022.120091 -
International Journal of Environmental... Apr 2020The present paper reviews available background information for studying multiple stressor effects of radon (Rn) and phthalates in children and provides insights on... (Review)
Review
The present paper reviews available background information for studying multiple stressor effects of radon (Rn) and phthalates in children and provides insights on future directions. In realistic situations, living organisms are collectively subjected to many environmental stressors, with the resultant effects being referred to as multiple stressor effects. Radon is a naturally occurring radioactive gas that can lead to lung cancers. On the other hand, phthalates are semi-volatile organic compounds widely applied as plasticizers to provide flexibility to plastic in consumer products. Links of phthalates to various health effects have been reported, including allergy and asthma. In the present review, the focus on indoor contaminants was due to their higher concentrations and to the higher indoor occupancy factor, while the focus on the pediatric population was due to their inherent sensitivity and their spending more time close to the floor. Two main future directions in studying multiple stressor effects of radon and phthalates in children were proposed. The first one was on computational modeling and micro-dosimetric studies, and the second one was on biological studies. In particular, dose-response relationship and effect-specific models for combined exposures to radon and phthalates would be necessary. The ideas and methodology behind such proposed research work are also applicable to studies on multiple stressor effects of collective exposures to other significant airborne contaminants, and to population groups other than children.
Topics: Air Pollutants, Radioactive; Air Pollution, Indoor; Asthma; Child; Environmental Exposure; Floors and Floorcoverings; Humans; Hypersensitivity; Plasticizers; Radon; Stress, Physiological
PubMed: 32331399
DOI: 10.3390/ijerph17082898 -
International Journal of Environmental... May 2022Plastics, as a polymer material, have long been a source of environmental concern. This paper uses polystyrene plastics as the research object, and the relative...
Plastics, as a polymer material, have long been a source of environmental concern. This paper uses polystyrene plastics as the research object, and the relative contribution of each component of plastic additives to plastic degradation is screened using the molecular dynamics method. The factorial experimental design method is combined with molecular dynamics simulation to adjust the additive composition scheme, analyze the mechanism of interaction between the additive components, and select the plastic additive combination that is most readily absorbed and degraded by microorganisms. Seven different types of plastic additives, including plasticizers, antioxidants, light and heat stabilizers, flame retardants, lubricants, and fillers, are chosen as external stimuli affecting the biodegradability of plastics. Using molecular dynamics simulation technology, it is demonstrated that plastic additives can promote the biodegradability of plastics. The factorial experimental design analysis revealed that all plastic additives can promote plastic biodegradation and plasticizer is the most favorable factor affecting plastic degradation, that hydrophobicity interactions are the primary reason for enhancing plastic degradation, and that screening No. 116-45 (plasticizer A, light stabilizer C, flame retardant E) is the most advantageous combination of biodegradable plastic additives. The plastic biodegradation effect regulation scheme proposed in this study is based on optimizing the proportion of additive components. To continue research on aquatic biodegradable plastics, the optimal combination of plastic components that can be absorbed and degraded by microorganisms is recommended.
Topics: Biodegradation, Environmental; Flame Retardants; Plasticizers; Plastics; Research Design
PubMed: 35565062
DOI: 10.3390/ijerph19095670 -
Biosensors Dec 2022As an antibody-free sensing membrane for the detection of the antibiotic tetracycline (TC), a liquid PVC membrane doped with the ion-pair tetracycline/θ-shaped anion...
As an antibody-free sensing membrane for the detection of the antibiotic tetracycline (TC), a liquid PVC membrane doped with the ion-pair tetracycline/θ-shaped anion [3,3'-Co(1,2-CBH)] ([-COSAN]) was formulated and deposited on a SWCNT modified gold microelectrode. The chosen transduction technique was electrochemical impedance spectroscopy (EIS). The PVC membrane was composed of: the tetracycline/[-COSAN] ion-pair, a plasticizer. A detection limit of 0.3 pg/L was obtained with this membrane, using bis(2-ethylhexyl) sebacate as a plasticizer. The sensitivity of detection of tetracycline was five times higher than that of oxytetracycline and of terramycin, and 22 times higher than that of demeclocycline. A shelf-life of the prepared sensor was more than six months and was used for detection in spiked honey samples. These results open the way to having continuous monitoring sensors with a high detection capacity, are easy to clean, avoid the use of antibodies, and produce a direct measurement.
Topics: Plasticizers; Tetracycline; Anti-Bacterial Agents; Microelectrodes; Antibodies; Oxytetracycline
PubMed: 36671906
DOI: 10.3390/bios13010071