Functional outcome of the one-stage scrotal tunnel + ventral inverted V incision + inverted Y anastomosis technique to treat penile paraffinoma: A single center retrospective study.

INTRODUCTION AND OBJECTIVE: Penis enlargement through substance injection is common in many countries of Southeast Asia and Eastern Europe. The definitive therapy involves removing the entire skin and the subcutaneous tissue and resurfacing the penile shaft via a single-stage or multi-staged procedure. This study aimed to report the functional outcome and esthetics of treating penile paraffinoma patients using the scrotal tunnel + ventral inverted V incision + anastomosis inverted Y technique. MATERIAL AND METHODS: This study was a single-center retrospective descriptive analysis of patients who underwent one-stage scrotal tunnel + ventral inverted V incision and inverted Y-shaped anastomosis procedures from January 2013 to December 2023. The following data were collected: chief complaint, reason for the injection, type of fluid injected, duration of surgery, duration of hospitalization, length of follow-up, and results after surgery. RESULTS: Of the 32 patients included in the study, 78% injected liquids in the form of oil and the goal of the majority of patients was penis enlargement (71%). The average age was 36.84 years, and the main complaint was pain in the penis during erection (53%). The average operation time was 130 minutes, hospitalization duration was 2.21 days, primary wound healing was 91%, patient satisfaction level was 97%, and Scale 4 erection hardness was 91%. CONCLUSION: One-stage surgery for penile paraffinoma produced promising results when the granuloma was limited to the penis and healthy scrotal skin was available to cover the penis.

Short Chain Chlorinated Paraffins Impaired Spermatogenesis Process in Mice via Inhibiting α-KG/TET Enzyme Activity.

Short chain chlorinated paraffins (SCCPs) are widely found in various environmental media and potentially threaten human health. However, the toxicity mechanisms of SCCPs to the male reproductive system remain unclear. In this study, male BALB/c mice and GC-1 cells were used to investigate the reproductive toxicity of SCCPs and their molecular mechanisms. SCCPs decreased the content of the tricarboxylic acid cycle intermediate α-KG in testicular cells, thus inhibiting the activity of the DNA demethylase TET enzyme and resulting in an increase in the overall methylation level of the testicular genome. Correspondingly, the promoter demethylation and expression of spermatogenesis-related genes Rbm46, Sohlh1, Kit, and Dmrt1 were significantly reduced by SCCPs, which further prevented the transformation of spermatogonia to spermatocytes and reduced sperm quality in mice. The in vitro experiments suggested that the TGFß pathway activated by oxidative stress might be an essential reason for inhibiting the tricarboxylic acid cycle and the reduction of α-KG content in testicular cells induced by SCCPs. Overall, this study reveals a novel metabolic regulatory mechanism of SCCPs-induced spermatogenesis disorders, which provides an essential theoretical basis for the prevention of reproductive toxicity of SCCPs.

Spatial distribution and air-soil exchange of short and medium chain chlorinated paraffins in Lahore, Pakistan.

This study provides the first systematic data on the distribution of short- (SCCPs) and medium chlorinated paraffins (MCCPs) in the atmosphere and surface soils of Lahore, Pakistan. The spatial distribution of SCCPs and MCCPs in air (n = 12) and soil (n = 15) was investigated from industrial, residential, commercial, conventional e-waste burning and background areas of Lahore. The concentrations ranged from below the limit of detection (

Polychlorinated alkanes in indoor environment: A review of levels, sources, exposure, and health implications for chlorinated paraffin mixtures.

Polychlorinated n-alkanes (PCAs) are the main components of chlorinated paraffins (CPs) mixtures, that have been commonly grouped into short-chain (SCCPs, C10-13), medium-chain (MCCPs, C14-17), and long-chain (LCCPs, C18-30) CPs. PCAs pose a significant risk to human health as they are broadly present in indoor environments and are potentially persistent, bioaccumulative, and toxic. The lack of specific terminology and harmonization in analytical methodologies for PCA analysis complicates direct comparisons between studies. The present work summarizes the different methodologies applied for the analysis of PCAs in indoor dust, air, and organic films. The large variability between the reviewed studies points to the difficulties to assess PCA contamination in these matrices and to mitigate risks associated with indoor exposure. Based on our review of physicochemical properties of PCAs and previously reported sum of measurable S/M/LCCPs levels, the homologue groups PCAs-C10-13 are found to be mostly present in the gas phase, PCAs-C14-17 in particulate matter and organic films, and PCAs-C≥18 in settled dust. However, we emphasized that mapping PCA sources and distribution in the indoors is highly dependent on the individual homologues. To further comprehend indoor PCA distribution, we described the uses of PCA in building materials and household products to apportion important indoor sources of emissions and pathways for human exposure. The greatest risk for indoor PCAs were estimated to arise from dermal absorption and ingestion through contact with dust and CP containing products. In addition, there are several factors affecting indoor PCA levels and exposure in different regions, including legislation, presence of specific products, cleaning routines, and ventilation frequency. This review provides comprehensive analysis of available indoor PCA data, the physicochemical properties, applied analytical methods, possible interior sources, variables affecting the levels, human exposure to PCAs, as well as need for more information, thereby providing perspectives for future research studies.

Rapid method for paraffin embedding of precision-cut liver slices.

Precision-cut liver slices (PCLS) are tissue explants extensively used as an ex vivo model for metabolism and toxicity studies. When in vitro assays are conducted, it is imperative to perform a histomorphological evaluation as part of the viability analyses throughout the assay time. It is considered that good quality PCLS histological sections are difficult to obtain because they are hard to manipulate, and may shrink or fold during processing. Moreover, bibliography is not detailed on the embedding processes used. In this article, we propose an adjusted and rapid method for paraffin embedding of PCLS from crossbreed steers. Each PCLS was covered with a piece of gauze and placed into a histological cassette. These cassettes were submitted to a series of baths: 80 % ethanol for 10 min; 3 baths of 96 % ethanol for 10 min; 3 baths of butanol for 10 min; 1 bath of butanol-paraffin (1:1) for 20 min in a 60 °C laboratory oven; and 3 baths of paraffin for 20 min in a 60 °C laboratory oven. Folded paper boxes were used to produce paraffin blocks. It was possible to obtain complete sections with preserved cell morphology and no artifacts, and tissue appearance was similar to previous PCLS processed through the routine protocol, demonstrating the adequacy of the method implemented.

Intercorrelations of Chlorinated Paraffins, Dechloranes, and Legacy Persistent Organic Pollutants in 10 Species of Marine Mammals from Norway, in Light of Dietary Niche.

Short-, medium-, and long-chain chlorinated paraffins (CPs) (SCCPs, MCCPs, and LCCPs) and dechloranes are chemicals of emerging concern; however, little is known of their bioaccumulative potential compared to legacy contaminants in marine mammals. Here, we analyzed SCCPs, MCCPs, LCCPs, 7 dechloranes, 4 emerging brominated flame retardants, and 64 legacy contaminants, including polychlorinated biphenyls (PCBs), in the blubber of 46 individual marine mammals, representing 10 species, from Norway. Dietary niche was modeled based on stable isotopes of nitrogen and carbon in the skin/muscle to assess the contaminant accumulation in relation to diet. SCCPs and dechlorane-602 were strongly positively correlated with legacy contaminants and highest in killer (Orcinus orca) and sperm (Physeter macrocephalus) whales (median SCCPs: 160 ng/g lw; 230 ng/g lw and median dechlorane-602: 3.8 ng/g lw; 2.0 ng/g lw, respectively). In contrast, MCCPs and LCCPs were only weakly correlated to recalcitrant legacy contaminants and were highest in common minke whales (Balaenoptera acutorostrata; median MCCPs: 480 ng/g lw and LCCPs: 240 ng/g lw). The total contaminant load in all species was dominated by PCBs and legacy chlorinated pesticides (63-98%), and MCCPs dominated the total CP load (42-68%, except 11% in the long-finned pilot whale Globicephala melas). Surprisingly, we found no relation between contaminant concentrations and dietary niche, suggesting that other large species differences may be masking effects of diet such as lifespan or biotransformation and elimination capacities. CP and dechlorane concentrations were higher than in other marine mammals from the (sub)Arctic, and they were present in a killer whale neonate, indicating bioaccumulative properties and a potential for maternal transfer in these predominantly unregulated chemicals.

Effect of honey and povidone-iodine on acute laceration wound healing: a pilot randomised controlled trial study.

OBJECTIVE: Acute laceration wound (ALW) is one of the most common injuries in Indonesia with potential significant morbidities. In rural areas, povidone-iodine and honey are commonly used as wound dressings. This study aimed to identify the effectiveness of honey compared to paraffin gauze and the commonly used povidone-iodine in improving ALW healing time. METHOD: This study was a single-blind, pilot randomised controlled trial (RCT) with three intervention groups (honey, povidone-iodine, and paraffin). The outcomes were wound healing time, slow healing, secondary healing, signs of infection, wound dehiscence, oedema, maceration, necrosis, exudate and cost. RESULTS: A total of 35 patients (male to female ratio: 4:1), with a mean age of 22.5 (range: 6-47) years, were included and randomised to treatment groups using predetermined randomisation according to wound location and wound dressing selection: honey group, n=12; povidone-iodine group, n=11; paraffin group, n=12 with one patient lost to follow-up. All groups achieved timely healing, with a mean healing time of 9.45±5.31 days and 11.09±5.14 days for the povidone-iodine and paraffin groups, respectively, and a median healing time of 10 (3-19) days for the honey group (p>0.05). More wounds in the honey group achieved healing in ≤10 days compared with the other groups. Both povidone-iodine and honey groups had fewer adverse events, with the latter having the lowest cost. CONCLUSION: In this study, honey was clinically effective in accelerating healing time with a lower cost compared to paraffin, and was comparable to povidone-iodine. Future RCTs with a larger sample size should be pursued to determine honey's role in ALW treatment.

Medium-Chain Chlorinated Paraffins Trigger Thyroid Hormone Synthesis and Interfere with Mitochondrial Function in the Thyroid Gland.

Medium-chain chlorinated paraffins (MCCPs, C14-C17) are frequently detected in diverse environmental media. It has been proposed to be listed in Annex A of the Convention on Persistent Organic Pollutants in 2023. Although MCCPs are a crucial health concern, their toxicity remains unclear. This study investigated the toxic effects of MCCPs (0.1-50 mg/kg body weight/day) on the thyroid gland of female Sprague-Dawley rats and characterized the potential toxic pathways via transcriptomics and metabolomics approaches. MCCPs exposure caused histopathological changes to the endoplasmic reticula and mitochondria in thyroid follicular cells at a dose of 50 mg/kg bw/d and increased serum thyrotropin-releasing hormone, thyroid-stimulating hormones, and thyroxine when exposed to a higher dose of MCCPs. Transcriptomic analysis indicated the excessive expression of key genes related to thyroid hormone synthesis induced by MCCPs. Integrating the dual-omics analysis revealed mitochondrial dysfunction of the thyroid by mediating fatty acid oxidation, Kreb's cycle, and oxidative phosphorylation. Significant metabolic toxicity on the thyroid might be linked to the characteristics of the chlorine content of MCCPs. This study revealed the toxicity of MCCPs to the thyroid gland via triggering thyroid hormone synthesis and interfering with mitochondrial function, which can provide new insights into the modes of action and mechanism-based risk assessment of MCCPs.

Tibetan lake sediment records reveal historical emission and long-range atmospheric transport of chlorinated paraffins.

The Tibetan Plateau, a recognized global sink for Persistent Organic Pollutants (POPs), lies adjacent to two major emitting regions, inland China and India. This unique geographical setting makes it a pivotal site for examining the presence and compositional evolution of POPs following their long-range atmospheric transport (LRAT). This study focuses on the current predominant POPs, chlorinated paraffins (CPs). We comprehensively screened 675 homologues of the very short- (vSCCPs), short- (SCCPs), medium- (MCCPs), and long-chain CPs (LCCPs) in six dated sediment cores across the extensive Tibetan area. The findings unveiled pronounced temporal disparities in CP concentrations and compositions between Tibet's southern and eastern sectors, reflecting divergent usage and emission chronicles of inland China and India. Notably, a market shift in China from regulated SCCPs to the in-use MCCPs and LCCPs was observed in the 21st century, contrasting with India's unregulated production of SCCPs. The Organization for Economic Cooperation and Development (OECD) Screening Tool, developed to assess the overall persistence (POV) and long-range transport potential (LRTP) of organic chemicals, elucidated the erosion of CP source signatures induced by fractionation, a process that intensifies with transport distance from the source regions. This study enhances our understanding of the emission inventories and LRAT behavior of these transitional regulatory contaminants, highlighting the Tibetan Plateau's crucial role as an environmental sentinel in global pollution dynamics.

Space-use strategy drives fine-scale spatial variation of chlorinated paraffins in indo-pacific humpback dolphins.

Contaminant accumulation in organisms can be influenced by both biological traits and environmental conditions. However, delineating the main factors affecting contaminant burdens in organisms remains challenging. Here, we conducted an initial investigation into the impact of diet and habitat on the accumulation of short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in Indo-Pacific humpback dolphins (2003-2020, n = 128) from the Pearl River Estuary (PRE), a highly polluted estuary in China. The detected levels of SCCPs (5897 ± 3480 ng g-1 lw) and MCCPs (13,960 ± 8285 ng g-1 lw) in blubber samples of humpback dolphin are the highest among recorded values marine mammals. Both SCCPs and MCCPs exhibited biomagnification factor values exceeding 1, suggesting their biomagnification potential within the dolphins and their diet. Quantitative diet analysis using the dolphin fatty acid signatures revealed that humpback dolphins inhabiting the western PRE consumed a larger proportion of carnivorous fish than those from the eastern PRE. However, spatial analysis showed that humpback dolphins in the western PRE contained lower SCCP/MCCP concentrations than those from the eastern PRE. Based on these findings we suggest that, compared to diet differences, spatial variations of SCCPs/MCCPs in humpback dolphins may be predominantly influenced by their space-use strategies, as the eastern PRE is closer to the pollutant discharge source and transfer routes.

Tissue-Specific Accumulation of Orally Administered Short- and Medium-Chain Chlorinated Paraffins in Honeybees (Apis mellifera L.).

The prevalence and distribution of chlorinated paraffins (CPs) have been extensively studied in various matrices and organisms; however, there is a lack of information about insects, particularly in honeybees. To address this gap, we studied young honeybee workers exposed to short- and medium-chain CPs (SCCPs and MCCPs) at an environmentally relevant concentration of 10 mg/L for 7 days, followed by a 7-day elimination period. Results indicated that CPs could transfer into the head after oral consumption and SCCPs and MCCPs exhibited clear bioaccumulation trends: midgut > hindgut > head. An evaluation of congener group distribution patterns demonstrated that the dominant congener groups in all target tissues were C11-13Cl7-8 and C14Cl7-8 for SCCPs and MCCPs, respectively, consistent with the treated CP standards. In honeybees, a significant negative relationship was observed for the log concentration of MCCP congener groups and their log KOW, but not with their log KOA. Conversely, no such correlation was found for SCCPs. These findings suggest that honeybees have a high potential to bioaccumulate MCCPs, particularly those with a low log KOW, and exhibit weak selectivity for SCCPs.

Human dermal exposure to short- and medium-chain chlorinated paraffins: Effect of populations, activities, gender, and haze pollution.

Human dermal exposure to chlorinated paraffins (CPs) has not been well documented. Therefore, hand wipes were collected from four occupational populations to analyze short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) in order to estimate dermal uptake and oral ingestion via hand-to-mouth contact. The total CP levels (∑SCCPs and ∑MCCPs) in wipes ranged from 71.4 to 2310 µg/m2 in security guards, 37.6 to 333 µg/m2 in taxi drivers, 20.8 to 559 µg/m2 in office workers, and 20.9 to 932 µg/m2 in undergraduates, respectively. Security guards exhibited the highest levels of ∑SCCPs among four populations (p < 0.01). In undergraduates engaged in outdoor activities, C13 emerged as the most dominant SCCPs homologue group, followed by C12, C11, and C10. The levels of ∑SCCPs and ∑MCCPs in males in light haze pollution were significantly higher than that in heavy haze pollution (p < 0.05). The median estimated dermal absorption dose of SCCPs and MCCPs via hand was 22.2 and 104 ng (kg of bw)-1 day-1, respectively, approximately 1.5 times the oral ingestion [12.3 and 74.4 ng (kg of bw)-1 day-1], suggesting that hand contact is a significant exposure source to humans.

A novel paraffin-based N/P controlled-release material for biostimulation of phenol biodegradation in groundwater.

To address the problem of the weak natural restoration ability of oligotrophic groundwater environments, a novel N/P controlled-release material (CRM) for biostimulation, prepared by an improved method, was developed. CRMs can encapsulate N and P (N/P) salts for sustained release in aquifers. Paraffin-based CRMs can be used to control N/P release rates by adjusting the particle size of CRMs and the mass ratio of the paraffin. The developed CRMs had a more remarkable adaptability to groundwater than other materials. Specifically, 0.4-cm CRMs released N/P stably and efficiently over a wide temperature range (7-25 â„ƒ), and the release properties of various CRMs were not affected by pH. The release of N/P followed Fickian diffusion, and a dissolution-diffusion model was established to elucidate the mechanism of the controlled release. In contrast to bare N/P, CRMs obviously enhanced the biodegradation rate of phenol and prolonged the effectiveness of supplying N/P. The degradation rate of phenol in the CRM system increased by 20.8 %. The different supply modes of N/P, CRMs and bare N/P, resulted in differences in salinity. Metagenomic analysis showed that this difference changed the proportion of various phenol-degrading genera and thus changed the abundance of genes associated with the phenol degradation pathway.

Self-inflicted ingestion of harmful chemicals in adolescents and adults: risk factors and characteristics.

BACKGROUND: Injury due to ingestion of harmful chemicals has become an area of concern globally. In South Africa, paraffin has been widely implicated in multiple health outcomes, including severe ingestion injuries. A specific category of such injuries is those that are self-inflicted. A significant proportion of self-inflicted ingestion is reported to be intentional, although intentionality for self-infliction may be difficult to determine. Nonetheless, the identification of key explanatory risks and demographic factors of self-inflicted ingestion may contribute towards a better understanding of self-inflicted and harmful chemical ingestion injuries. METHODS: This study used secondary data that had been collected on burn injuries of all causes, including those due to the ingestion of harmful chemicals, from a sample of South Africans from low-income communities close to major metropolitan centres. The current analysis focused on the risks for self-inflicted ingestion injuries and used logistic regression to determine risks for self-inflicted ingestion as differentiated from ingestion due to the actions of another person (other-inflicted ingestion) by sex and age cohort of the victim, and the presence of alcohol, by examining paraffin ingestion versus that of other chemicals. RESULTS: The overwhelming majority of ingestion injuries (92.1%) were self-inflicted. The current findings indicate that sex (with females almost twice as likely to present with self-inflicted ingestion), age cohort (with those aged 18-29 and 30-44 years old four times more likely affected than older adults), presence of alcohol (twice as likely present than amongst individuals reporting ingestion injuries inflicted by others), and chemicals other than paraffin (three times more likely) are key explanatory factors for an increased risk for self-inflicted ingestion of harmful chemicals. CONCLUSIONS: The study empirically confirms the role of several key risk factors in what remains a relatively unreported and understudied phenomenon, but which appears to align with the demographic and risk profile reported for suicidal injuries through chemical ingestion, i.e. intentional self-inflicted ingestion. The findings may contribute towards improved safety policies on the availability and sale of chemical products and more focussed community interventions for at-risk individuals such as females and young people. It also flags the importance of assessing for alcohol use and alcohol use disorders at hospital admission of self-ingestion injuries.

Cattle hair as a bioindicator for short- and medium-chain chlorinated paraffin monitoring on cattle farms.

Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) are hazardous industrial chemicals that tend to bioaccumulate in animal-derived foodstuffs through the food supply chain. However, the lack of reliable noninvasive bioindicators hinders the monitoring of farm animal exposure to CPs. In this study, 169 cattle hair samples were collected from beef cattle farms in six Chinese provinces, with further beef, feed, and soil samples being collected in Hebei province. Geographical differences in CP concentrations were observed in the hair samples, and CP concentrations in samples collected from Hebei province decreased in the following order: hair > feed > beef > soil. C10-11Cl6-7 and C14Cl7-8 were the predominant SCCPs and MCCPs, respectively, in all the hair, beef, feed, and soil samples. CP concentrations in hair samples significantly correlated with those in beef, feed, and soil samples, indicating that hair can be used as a bioindicator of cattle exposure to CPs. The possible health risks associated with exposure to CPs through beef consumption, especially for children and high-volume beef consumers, should be further investigated.

Stepping-up accurate quantification of chlorinated paraffins: Successful certification of the first matrix reference material.

BACKGROUND: Chlorinated paraffins (CPs) are industrial chemicals categorised as persistent organic pollutants because of their toxicity, persistency and tendency to long-range transport, bioaccumulation and biomagnification. Despite having been the subject of environmental attention for decades, analytical methods for CPs still struggle reaching a sufficient degree of accuracy. Among the issues negatively impacting the quantification of CPs, the unavailability of well-characterised standards, both as pure substances and as matrix (certified) reference materials (CRMs), has played a major role. The focus of this study was to provide a matrix CRM as quality control tool to improve the comparability of CPs measurement results. RESULTS: We present the process of certification of ERM®-CE100, the first fish reference material assigned with certified values for the mass fraction of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The certification was performed in accordance with ISO 17034:2016 and ISO Guide 35:2017, with the value assignment step carried out via an intercomparison of laboratories of demonstrated competence in CPs analysis and applying procedures based on different analytical principles. After confirmation of the homogeneity and stability of the CRM, two certified values were assigned for SCCPs, depending on the calibrants used: 31 ± 9 µg kg-1 and 23 ± 7 µg kg-1. The MCCPs certified value was established as 44 ± 17 µg kg-1. All assigned values are relative to wet weight in the CRM that was produced as a fish paste to enhance similarity to routine biota samples. SIGNIFICANCE AND NOVELTY: The fish tissue ERM-CE100 is the first matrix CRM commercially available for the analysis of CPs, enabling analytical laboratories to improve the accuracy and the metrological traceability of their measurements. The certified CPs values are based on results obtained by both gas and liquid chromatography coupled with various mass spectrometric techniques, offering thus a broad validity to laboratories employing different analytical methods and equipment.

High thermal buffer and radiative cooling sodium alginate-based Janus aerogel enables multi-scenario thermal management for firefighting clothing.

Firefighting clothing is an indispensable protective equipment for firefighters performing rescue activities under extreme heat and fire conditions. However, few bio-based thermal management materials that provide thermal comfort to firefighters in different operational scenarios have been reported. Herein, we present a novel strategy to prepare Janus-type aerogels based on sodium alginate biological macromolecules, consisting of a SiO2 nanoparticle layer and a microencapsulated paraffin@SiO2 phase-change composite layer. A passive radiative cooling and thermal energy storage was integrated into a functional dual-mode material system. Results show that Janus-type aerogel to cool down by 11.5 °C on a hot summer day. Meanwhile, paraffin@SiO2 has a high melting enthalpy of 127.5 J g-1 that effectively buffers temperature rise during the phase-change process. This Janus-type aerogel has ultra-low heat insulation (0.042 W/(m·K)), it can delay approximately 76.6 s to reach second-degree burn time for skin at a radiant heat exposure of 18.4 kW m-2. The work provides an innovative way to develop bio-based thermal management materials, which could enable multi-scenario thermal management for firefighting clothing.

Influence of two paraffin wax chewing gums with different con-sistencies on the stimulated salivary flow rate.

This study investigated and compared the consistency and compressive strength of two commercially available paraffin wax chewing gums (Aurosan (AU) and GC Europe (GC)), as well as their impact on stimulated salivary flow rate. Instrumental texture analysis was uti-lized to assess the consistency and compressive strength of AU and GC during a 7-min chewing period. Subsequently, stimulated salivary flow rate (sSFR) was evaluated in healthy subjects using AU and GC over a 7-minute period. The compressive strengths from the pre-liminary test were compared over time with the sialometry data. Eighty-one test subjects, comprising 33 men and 48 women, participated. Over the 7-min measurement period, dif-ferences were observed in the total amount of saliva accumulated per minute. Direct com-parison of AU and GC revealed that regardless of age and gender, the amount of saliva formed after 1 min was 0.63 times less with AU than with GC (95% CI: 0.56 - 0.70; P < 0.001). The accumulated saliva volume with AU was also significantly lower than that with GC in the first 4 min (P = 0.016). However, from minute 5 onwards, the two products no longer showed statistical differences in the total amount of saliva. Comparison of the com-pressive strength of AU and GC showed that the values after 1 and 2 min were significantly higher for AU than for GC (P < 0.05); for all other time points, the compressive strength was higher for GC. In the mixed-effects model after log-transformation of compressive strength and saliva volume, GC exhibited decreasing saliva volumes with increasing compressive strength (P <0.001). Conversely, the opposite was observed for AU (P = 0.019). The study suggests that the consistency or compressive strength of paraffin wax chewing gums from different manufacturers could impact sSFR.

Characterization and health risks of short- and medium-chain chlorinated paraffins in the gas and size-fractionated particulate phases in ambient air.

Short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) have garnered significant attention because they have persistence and potential toxicity, and can undergo long-distance transport. Chlorinated paraffins (CPs) inhaled in the size-fractionated particulate phase and gas phase can carry different risks to human health due to their ability to accumulate in different regions of the respiratory tract and exhibit varying deposition efficiencies. In our study, large-volume ambient air samples in both the size-fractionated particulate phase (Dp < 1.0 µm, 1.0-2.5 µm, 2.5-10 µm, and Dp ≥ 10 µm) and gas phase were collected simultaneously in Beijing using an active sampler. The overall levels of SCCPs and MCCPs were relatively high, the ranges being 57-881 and 30-385 ng/m3, respectively. SCCPs tended to be partitioned in the gas phase (on average 75% of the ΣSCCP concentration), while MCCPs tended to be partitioned in the particulate phase (on average 62% of the ΣMCCP concentration). Significant correlations were discovered between the logarithm-transformed gas-particle partition coefficients (KP) and predicted subcooled vapor pressures (PL0) (p < 0.01 for SCCPs and MCCPs) and between the logarithm-transformed KP values and octanol-air partition coefficients (KOA) (p < 0.01 for SCCPs and MCCPs). Thus, the slopes indicated that organic matter absorption was the dominant process involved in gas-particle partitioning. We used the ICRP model to calculate deposition concentrations for particulate-associated CPs in head airways region (15.6-71.4 ng/m³), tracheobronchial region (0.8-4.8 ng/m³), and alveolar region (5.1-21.9 ng/m³), then combined these concentrations with the CP concentrations in the gas phase to calculate estimated daily intakes (EDIs) for inhalation. The EDIs for SCCPs and MCCPs through inhalation of ambient air for the all-ages group were 67.5-184.2 ng/kg/day and 19.7-53.7 ng/kg/day, respectively. The results indicated that SCCPs and MCCPs in ambient air do not currently pose strong risks to human health in the study area.

Short- and medium-chain chlorinated paraffins in surface sediment from Lake Ontario.

Concentrations of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) were analyzed and investigated in surficial sediment collected in 2018 from ten different nearshore sites in Lake Ontario and the St. Lawrence River influenced by inputs from varying urban and historical land uses. Sites were grouped into two categories of tributary and lake according to their location. Results show that tributary sites had higher concentrations of total chlorinated paraffin (CP) than lake sites. Humber Bay, a lake site, had the highest total CP concentration (55,000 ng/gTOC) followed by Humber River, a tributary site (50,000 ng/gTOC). The lowest concentrations were found in eastern Lake Ontario and Lake St. Francis in the St. Lawrence River (540 ng/gTOC). Higher concentrations of chlorinated paraffins (CPs) were found where runoff and wastewater inputs from urban areas, current industrial activities, and population were the greatest. Levels of MCCPs were higher than SCCPs at all sites but one, Lake St. Francis. Among the SCCPs, C13 and among the MCCPs C14 were the dominant chain length alkanes, with C14 being the highest among both groups. The SCCPs and MCCPs profiles suggest that they can be used to distinguish between sites impacted by local sources vs. sites impacted by short-/long-range transport of these chemicals.