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Journal of Hazardous Materials Jun 2021Aquatic foods are important sources of chlorinated paraffins (CPs) to humans. Farmed crabs are bottom-dwelling aquatic animals, and can accumulate CPs through food and...
Aquatic foods are important sources of chlorinated paraffins (CPs) to humans. Farmed crabs are bottom-dwelling aquatic animals, and can accumulate CPs through food and aquatic environment. However, limited information is available on CPs concentrations in and sources to farmed crabs. In this study, short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) concentrations in 59 samples from the farmed crab food web (crab, crab feed, and aquaculture environment) were determined. The samples were from 17 crab farms in Anhui Province, Jiangxi Province, and Shanghai, in China. The SCCPs and MCCPs concentrations in the crab samples were 82-1760 and not detected-680 ng/g lipid weight, respectively. The dominant SCCPs and MCCPs in the crab samples were CCl and CCl, respectively. The SCCPs concentrations in the crab food web samples were higher than the MCCPs concentrations. SCCPs contamination of the crab food web samples was not directly related to CPs product use. The main factors affecting SCCPs concentrations in the crab samples were different for different crab farms. Crab feed and the aquaculture environment could be sources of SCCPs to farmed crabs. No marked health risks are posed to humans through consuming CPs in Chinese mitten crabs farmed in China.
Topics: Animals; China; Environmental Monitoring; Humans; Hydrocarbons, Chlorinated; Paraffin; Seafood
PubMed: 33485226
DOI: 10.1016/j.jhazmat.2021.125076 -
A mechanical evaluation of micro-HA/CS composite scaffolds with interconnected spherical macropores.Biomedical Engineering Online Feb 2016In the process of bone defective reparation and engineered bone tissue construction, osteoblasts are adhered to the surface of the scaffold materials and impart the...
BACKGROUND
In the process of bone defective reparation and engineered bone tissue construction, osteoblasts are adhered to the surface of the scaffold materials and impart the external mechanical load to the osteoblasts. So, the dynamic mechanical property of the scaffolds play an important role in the bone tissue repair and it is valuable to research. Material type and the architectural design of scaffolds are also important to facilitate cell and tissue growth. The aim of this study was to prepare a kind of material with good pore connectivity and analyze its dynamic mechanical property.
METHODS
Fabrication and characterization of micro-hydroxyapatite(m-HA)/chitosan(CS) polymer composite scaffolds with well interconnected spherical pore architectures were reports. Micro-HA was prepared by being calcined and ball milled. Paraffin spheres in the range of 160-330 µm were fabricated with a dispersion method and used as the porogen in the fabrication of the scaffolds. Polymer scaffolds were fabricated by the technique of compression molding and particulate leaching method. The effects of the porogen content on the properties of the scaffolds were studied.
RESULTS
With the increase of porogen, the pore of the scaffolds increased and became interconnected. Cyclic loading of three scaffolds were tested with 10 % strain under four levels of loading frequency, 0.1, 0.5, 1 and 1.5 Hz. The porous composite scaffolds exhibited a viscosity-elastic behaviour with a maximum stress of 3-4 kPa. At each frequency, modulus value is decreased with the paraffin microspheres content, but there was no significance difference in the peak stress of the three samples. All the samples tested displayed clear hysteresis loops. There was no significance difference in the peak hysteresis of the three samples, and the hysteresis difference values between the sixth compression cycle and the initial cycle for three samples was similar, with no statistically significant differences.
CONCLUSIONS
Micro-HA/CS composite scaffolds with interconnected spherical macropores were fabricated using pherical paraffin as porogen. The porous composite scaffolds exhibited a viscosity-elastic behaviour with good repeatability. It is benefit to study the influence of the mechanical load on the cell of the scaffold.
Topics: Biocompatible Materials; Chitosan; Durapatite; Mechanical Phenomena; Paraffin; Particle Size; Porosity; Tissue Scaffolds; Water
PubMed: 26831146
DOI: 10.1186/s12938-015-0114-5 -
Environmental Pollution (Barking, Essex... Jun 2018Indo-Pacific humpback dolphin (Sousa chinensis) are chronically exposed to organic pollutants since they inhabit shallow coastal waters that are often impacted by... (Review)
Review
Indo-Pacific humpback dolphin (Sousa chinensis) are chronically exposed to organic pollutants since they inhabit shallow coastal waters that are often impacted by anthropogenic activities. The aim of this review was to evaluate existing knowledge on the occurrence of organic pollutants in Indo-Pacific humpback dolphins, identify knowledge gaps, and offer recommendations for future research directions. We discussed the trends in the bioaccumulation of organic pollutants in Indo-Pacific humpback dolphins focusing on sources, physicochemical properties, and usage patterns. Furthermore, we examined factors that influence bioaccumulation such as gender, age, dietary intake and tissue-specific distribution. Studies on bioaccumulation in Indo-Pacific humpback dolphin remain scarce, despite high concentrations above 13,000 ng/g lw we previously detected for PFOS, ∑PBDE and chlorinated paraffins. The maximum concentration of organochlorines detected was 157,000 ng/g wt. Furthermore, variations in bioaccumulation were shown to be caused by factors such as usage patterns and physicochemical properties of the pollutant. However, restrictions in sampling inhibit investigations on exposure pathway and toxicity of organic pollutants in Indo-Pacific humpback dolphin. We proposed the use of biopsy sampling, predictive bioaccumulation and toxicity modeling, and monitoring other emerging contaminants such as microplastics and pharmaceuticals for future health risk assessment on this critically endangered marine mammal species.
Topics: Animals; Dolphins; Environmental Monitoring; Hydrocarbons, Chlorinated; Paraffin; Plastics; Water Pollutants, Chemical
PubMed: 29477865
DOI: 10.1016/j.envpol.2018.01.055 -
The Science of the Total Environment May 2024Short (SCCPs) and medium (MCCPs) chain chlorinated paraffins being the emerging organic pollutants have raised serious concerns due to their widespread use and related...
Short (SCCPs) and medium (MCCPs) chain chlorinated paraffins being the emerging organic pollutants have raised serious concerns due to their widespread use and related human health risks. However, their occurrence in aquatic bodies like rivers and associated damage to ecological integrity is yet unknown in some regions of the world. The current study is the first ever assessment of SCCPs and MCCPs in sediment and water of river Ravi, Pakistan. Spatial occurrence and associated ecological risks were investigated from sediments (n = 16) and composite water samples (n = 8) collected at eight locations along the stretch of river Ravi. The concentrations of SCCPs and MCCPs varied from below limit of detection (
Topics: Humans; Animals; Chlorine; Hydrocarbons, Chlorinated; Paraffin; Rivers; Pakistan; Environmental Monitoring; Risk Assessment; Carbon; China
PubMed: 38537810
DOI: 10.1016/j.scitotenv.2024.171964 -
International Journal of Legal Medicine Nov 2022Routine coronal paraffin-sections through the dorsal frontal and parieto-occipital cortex of a total of sixty cases with divergent causes of death were...
Routine coronal paraffin-sections through the dorsal frontal and parieto-occipital cortex of a total of sixty cases with divergent causes of death were immunohistochemically (IHC) stained with an antibody against TMEM119. Samples of cerebrospinal fluid (CSF) of the same cases were collected by suboccipital needle-puncture, subjected to centrifugation and processed as cytospin preparations stained with TMEM119. Both, cytospin preparations and sections were subjected to computer-assisted density measurements. The density of microglial TMEM119-positive cortical profiles correlated with that of cytospin results and with the density of TMEM119-positive microglial profiles in the medullary layer. There was no statistically significant correlation between the density of medullary TMEM119-positive profiles and the cytospin data. Cortical microglial cells were primarily encountered in supragranular layers I, II, and IIIa and in infragranular layers V and VI, the region of U-fibers and in circumscribed foci or spread in a diffuse manner and high density over the white matter. We have evidence that cortical microglia directly migrate into CSF without using the glympathic pathway. Microglia in the medullary layer shows a strong affinity to the adventitia of deep vessels in the myelin layer. Selected rapidly fatal cases including myocardial infarcts and drowning let us conclude that microglia in cortex and myelin layer can react rapidly and its reaction and migration is subject to pre-existing external and internal factors. Cytospin preparations proved to be a simple tool to analyze and assess complex changes in the CNS after rapid fatal damage. There is no statistically significant correlation between cytospin and postmortem interval. Therefore, the quantitative analyses of postmortem cytospins obviously reflect the neuropathology of the complete central nervous system. Cytospins provide forensic pathologists a rather simple and easy to perform method for the global assessment of CNS affliction.
Topics: Biomarkers; Humans; Membrane Proteins; Microglia; Paraffin; Spinal Puncture; White Matter
PubMed: 35821334
DOI: 10.1007/s00414-022-02863-5 -
Journal of Hazardous Materials Aug 2020Gestation and lactation are very sensitive and vulnerable stages for human growth and development. During these two periods, short-chain chlorinated paraffins (SCCPs)...
Gestation and lactation are very sensitive and vulnerable stages for human growth and development. During these two periods, short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) can be transported to neonates via transplacental and breastfeeding transfers, and eventually posing potential adverse effects to neonates. Up to date, no simultaneous investigation of prenatal and postnatal exposure of CPs is reported. To bridge this knowledge gap, we have analyzed SCCPs and MCCPs in 20 complete sets of maternal serum, umbilical cord serum, placenta, and breast milk. The levels of both ∑SCCP and ∑MCCP followed the order of maternal serum > breast milk > cord serum > placenta. The breastfeeding transfer ratios (R ≈ 1.0) of CPs were greater than the corresponding transplacental transfer ratios (R < 1.0), demonstrating the higher transport of CPs during the lactation period. The placental retention/or accumulation ratios (R) showed that CPs were effectively retained by the placental barrier. Furthermore, the total exposure amount of SCCPs and MCCPs during the lactation period was> 100 times higher than the gestation exposure amounts. This study helps to better understand the prenatal and postnatal exposure of CPs and provides a solid basis for accurate human health risk assessment of CPs.
Topics: China; Environmental Monitoring; Female; Humans; Hydrocarbons, Chlorinated; Infant, Newborn; Mothers; Paraffin; Pregnancy; Risk Assessment
PubMed: 32344298
DOI: 10.1016/j.jhazmat.2020.122660 -
Environmental Science & Technology Jun 2022The last few decades have seen ubiquitous and increasing contamination of chlorinated paraffins (CPs) worldwide. Here, we develop the first global inventories of...
The last few decades have seen ubiquitous and increasing contamination of chlorinated paraffins (CPs) worldwide. Here, we develop the first global inventories of production, use, in-use stocks, and emissions of total CPs, including the short-, medium- and long-chain components (SCCPs, MCCPs, and LCCPs) during 1930-2020 using a dynamic substance flow analysis model named Chemical in Products Comprehensive Anthroposhpheric Fate Estimation. The model estimates that a total of ∼33 million metric tons of CPs have been produced and used globally, ∼40% of which still resided in in-use products by 2020 and is available for long-term emissions in the next decades. Global cumulative emissions of CPs have increased to ∼5.2 million metric tons by 2020, with SCCPs, MCCPs, and LCCPs accounting for ∼30, 40, and 30%, respectively. While the production, use, and emissions of CPs started declining in regions such as Western Europe, they remain high in China. The model also suggests that homologues with 10, 14, and 22-23 carbons were predominant in the cumulatively produced and emitted SCCPs, MCCPs, and LCCPs, respectively. The emission estimates were evaluated by generating environmental concentrations that are comparable to literature-reported environmental monitoring data. Our estimates provide opportunities to link the environmental fate and occurrence of CPs to emission sources and lay the basis for future risk-reduction strategies of CPs around the world.
Topics: Carbon; China; Environmental Monitoring; Hydrocarbons, Chlorinated; Paraffin
PubMed: 35536664
DOI: 10.1021/acs.est.2c00264 -
Environmental Science and Pollution... Mar 2019A method for the analysis of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) in house dust was developed. The method is based on sonication...
A method for the analysis of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) in house dust was developed. The method is based on sonication extraction, sample cleanup by solid phase extraction (SPE), and separation and detection by gas chromatography coupled with mass spectrometry (GC/MS) operated in electron capture negative ion (ECNI) chemical ionization mode. The method is sensitive, with method detection limits (MDLs) down to 0.22 μg/g for SCCPs and 0.55 μg/g for MCCPs. The overall recoveries of the method were 104 (± 11)% and 108 (± 16)% for SCCPs and MCCPs, respectively. The method was successfully applied to the analysis of SCCPs and MCCPs in NIST standard reference material (SRM 2585, organic contaminants in house dust) and a subset of house dust samples collected under the Canadian House Dust Study (CHDS). Average concentrations of SCCPs and MCCPs in SRM 2585 (n = 12 replicates) were 7.58 (± 0.43) μg/g for SCCPs and 16.4 (± 2.1) μg/g for MCCPs, respectively. A comparison was made between CP concentrations in paired dust samples collected using two different methods from the same homes: fresh or "active" dust (FD) collected by technicians and a sample taken from the household vacuum cleaner (HD). Spearman rank analysis showed a significant positive correlation (p < 0.01) between FD and HD samples for both MCCPs and SCCPs. CPs were detected in every house dust sample (n = 48 HD samples), with median (range) concentrations of 6.2 (4.0 - 57) μg/g and 19 (5.9-901) μg/g for SCCPs and MCCPs, respectively. Widely scattered CP levels and 100% detection frequency in this preliminary set of 48 HD samples suggest a wide variability in Canadian household exposures to CPs.
Topics: Air Pollutants; Air Pollution, Indoor; Canada; Dust; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Hydrocarbons, Chlorinated; Paraffin; Solid Phase Extraction
PubMed: 30656583
DOI: 10.1007/s11356-018-04073-2 -
Environmental Science & Technology Dec 2022Determining the major human exposure pathways is a prerequisite for the development of effective management strategies for environmental pollutants such as chlorinated...
Determining the major human exposure pathways is a prerequisite for the development of effective management strategies for environmental pollutants such as chlorinated paraffins (CPs). As a first step, the internal and external exposure to CPs were quantified for a well-defined human cohort. CPs in participants' plasma and diet samples were analyzed in the present study, and previous results on paired air, dust, and hand wipe samples were used for the total exposure assessment. Both one compartment pharmacokinetic modeling and forensic fingerprinting indicate that dietary intake contributed the most to body burden of CPs in this cohort, contributing a median of 60-88% of the total daily intakes. The contribution from dust ingestion and dermal exposure was greater for the intake of long-chain CPs (LCCPs) than short-chain CPs (SCCPs), while the contribution from inhalation was greater for the intake of SCCPs than medium-chain CPs (MCCPs) and LCCPs. Significantly higher concentrations of SCCPs and MCCPs were observed in diets containing butter and eggs, respectively ( < 0.05). Additionally, other exposure sources were correlated to plasma levels of CPs, including residence construction parameters such as the construction year ( < 0.05). This human exposure to CPs is not a local case. From a global perspective, there are major knowledge gaps in biomonitoring and exposure data for CPs from regions other than China and European countries.
Topics: Humans; Paraffin; Hydrocarbons, Chlorinated; Body Burden; Environmental Monitoring; Dust; Eating; China
PubMed: 36378808
DOI: 10.1021/acs.est.2c04998 -
Environmental Science. Processes &... May 2023Short-chain chlorinated paraffins (SCCPs) were listed for elimination under the Stockholm Convention in 2017 due to their persistence and toxicity. Although Canada and...
Short-chain chlorinated paraffins (SCCPs) were listed for elimination under the Stockholm Convention in 2017 due to their persistence and toxicity. Although Canada and other Stockholm signatories have prohibited the manufacture, usage and import of SCCPs since 2013, they can still be detected at high concentrations in indoor dust. To identify the sources of the SCCPs in the Canadian indoor environment, short-, medium- and long-chain chlorinated paraffins (SCCPs, MCCPs, LCCPs, respectively) were measured using a sensitive LC-ESI-orbitrap method. SCCPs were detected in 84 of the 96 products purchased in Canada after 2013 (87.5%) including electronic devices, clothing, plastics (toys), and paintings. Concentrations of SCCPs were up to 0.93% (9.34 mg g). SCCPs were also detected in newly purchased toys at 0.005-2.02 mg g, indicating the potential for children's exposure. Profiles of chlorinated paraffins differed among categories of products. For example, C-SCCPs were most common in toys, while electronic devices like headphones showed comparable concentrations of SCCPs and MCCPs. Additionally, four new carboxylate derivatives of CPs were detected in an electronic device sample. These are the first data to show the ubiquitous occurrences of SCCPs in a wide range of products currently marketed in Canada, suggesting continuing indoor exposure to SCCPs despite their prohibition.
Topics: Child; Humans; Paraffin; Hydrocarbons, Chlorinated; Environmental Monitoring; Canada; Dust; China
PubMed: 37039315
DOI: 10.1039/d2em00494a