Cancer risk from gaseous carbonyl compounds in indoor environment generated from household coal combustion in Xuanwei, China

Airborne carbonyls were characterized from emitted indoor coal combustion. Samples were collected in Xuanwei (Yunnan Province), a region in China with a high rate of lung cancer. Eleven of 19 types of samples (58%) demonstrated formaldehyde concentrations higher than the World Health Organization exposure limit (a 30-min average of 100 μg m−3). Different positive significant correlations between glyoxal/methylglyoxal and formaldehyde/acetaldehyde concentrations were observed, suggesting possible different characteristics in emissions between two pairs of carbonyl compounds. A sample in the highest inhalation risk shows 29.2 times higher risk than the lowest sample, suggesting different coal sampling locations could contribute to the variation of inhalation risk. Inhabitants in Xuanwei also tend to spend more time cooking and more days per year indoors than the national average. The calculated cancer risk ranged from 2.2–63 × 10−5, which shows 13 types of samples at high-risk level. Cumulative effect in combination with different carbonyls could have contributed to the additive actual inhalation cancer risk. There is a need to explicitly address the health effects of environmentally relevant doses, considering life-long exposure in indoor dwellings

Speciation of metals in agricultural lime and contaminated soil

Die Verwendung von Metallen zur Entwicklung der heutigen fortschrittlichen technologischenrnGesellschaft lässt auf eine lange Geschichte zurück blicken. Im Zuge des letzten Jahrhundertsrnwurde realisiert, dass die chemischen und radioaktiven Eigenschaften von Metallen einernernsthafte Bedrohung für die Menschheit darstellen können. In der modernen Geochemie ist esrnallgemein akzeptiert, dass die spezifischen physikochemische Formen entscheidender sind, alsrndas Verhalten der gesamten Konzentration der Spurenmetalle in der Umwelt. Die Definition derrnArtbildung kann grob als die Identifizierung und Quantifizierung der verschiedenen Formen oderrnPhasen für ein Element zugeordnet werden. Die chemische Extraktion ist eine gemeinsamernSpeziierungstechnik bei der die Fraktionierung des Gesamtmetallgehaltes zur Analyse der Quellernanthropogener Metallkontamination und zur Vorhersage der Bioverfügbarkeit von verschiedenenrnMetallformen dient. Die Philosophie der partiellen und sequenziellen Extraktionsmethodernbesteht darin, dass insbesondere das Extraktionsmittel phasenspezifisch unter chemischemrnAngriff unterschiedlicher Mischungsformen steht. Die Speziation von Metall ist wichtig bei derrnBestimmung der Toxizität, Mobilität, Bioverfügbarkeit des Metalls und damit ihr Schicksal inrnder Umwelt und biologischem System. Die Artenbildungsanalyse kann für das Verständnis derrnAuswirkung auf die menschliche Gesundheit und bei ökologischen Risiken durch diernQuantifizierung von Metallspezies bei einem Untersuchungs-standort angewendet werden undrnanschließend können Sanierungsstrategien für den Standort umgesetzt werden. Mit Hilfe derrnSpezifizierung wurden Arsen und Kupfer in landwirtschaftlichem Kalkdünger und Thallium inrnkontaminierten Böden untersucht und in den folgenden Abschnitten im Einzelnen dargestellt.There is a long history of human using metals in developing an advanced technological society.rnIt has only been realized until the past century that metal’s chemical and radioactive propertiesrncan pose serious threat to mankind. In modern day geochemistry it is widely accepted that thernspecific physiochemical forms rather than the total concentration decides the ultimate trace metalrnbehavior in an environment. The definition of speciation can be broadly classified as thernidentification and quantification of the different forms or phases for an element. Chemicalrnextraction is a common speciation technique in which fractionating total metal content forrnanalyzing the source of anthropogenic metal contamination and also to predict bioavailability ofrnvarious metal forms. The philosophy of the partial and sequential extraction method is to assumernthat particular extractant is phase specific under chemical attack on a mixture of forms.rnSpeciation of metal is important in determining metal’s toxicity, mobility, bioavailability andrnhence their fate in environment and biological systems. Speciation analysis can be applied inrnunderstanding the impact on human health and ecological risks by quantifying the metal speciesrnat a sampling site and subsequently suitable remediation strategies can be implemented for thernlocation. Speciation of arsenic and copper in agricultural lime and thallium in contaminated soilsrnwere investigated and revealed in the following sections

Speciation and mobility of arsenic in agricultural lime

Agricultural liming materials are used to correct soil acidity and to improve plant growth and microbial functionality. A relatively low-grade agricultural lime was found to contain up to 125 mg kg(-1) arsenic (As), which is above an), fertilizing materials code threshold. The color of the milled material is brown due to ample oxide dendrites. Microprobe elemental maps confirmed that these accessory oxide mineral phases are responsible for the elevated As concentrations in the limestone. The black Mn-bearing dendrites contain minor amounts of As, whereas the brown Fe-bearing dendrites contain the major part of the As inventory, with an Fe/As molar ratio around 100. Because the elemental maps represent only a few sample regions of interest (ROI), the results are corroborated by a bulk five-step sequential extraction of the lime, which suggests that a majority of the As is bound to acid-reducible phases. Because repartitioning of the As oxyanion during extraction cannot be ruled out, X-ray absorption spectroscopy with micrometer resolution (mu-XAS) was used as a solid-state speciation analysis approach. The mu-XAS results at the Fe K-edge for the selected ROIs revealed the brown dendrites to consist of ferrihydrite and goethite, whereas those at the As K-edge revealed chat the pentavalent As species arsenate predominates, with As-Fe distance and coordination indicating binding as 1 mononuclear inner-spheric adsorbate complex. Batch experiments with soil exposed to submerged conditions of up to 41 d revealed a negligible As, release rate from the lime (approximately 40 ng kg(-1) d(-1)). Tie results of this study corroborate regulatory codes that set the permissible As content in agricultural lime relative to the respective Fe content

Endoscopic Resection of Localized Pigmented Villonodular Synovitis in the Hoffa Fat Pad

Pathologies within the fat pad can have either intrinsic or extrinsic causes. Most of them are the consequences of trauma and degeneration, but inflammatory and neoplastic diseases can arise in the fat pad. Pigmented villonodular synovitis is the most common space-occupying lesion of the Hoffa fat pad, followed by ganglion. The purpose of this Technical Note is to describe the details of endoscopic resection of localized pigmented villonodular synovitis in the Hoffa fat pad. Hopefully, this can allow complete resection of the lesion with minimal surgical trauma and scar tissue formation

Arthroscopic Dorsal Closing-Wedge Osteotomy of Metatarsal Head for Management of Freiberg Infraction

Freiberg infraction is a relatively rare osteochondrosis of the lesser metatarsal head. Operative treatment is indicated if conservative treatment fails to relieve the pain. Dorsal closing-wedge osteotomy is a realignment osteotomy of the metatarsal head and neck to redirect the articular surface, allowing the intact plantar cartilage to articulate with the proximal phalanx. The purpose of this technical note is to describe the details of arthroscopic dorsal closing-wedge osteotomy of the metatarsal head for management of Freiberg infraction. Although dorsal closing-wedge osteotomy has been proposed for the treatment of late-stage Freiberg infraction, we reserve this technique for early stages of the disease

Abiotic Formation of Humic-Like Substances through Freezing-Accelerated Reaction of Phenolic Compounds and Nitrite

A previously unknown abiotic humification pathway which is highly accelerated in frozen solution containing phenolic compounds and nitrite was investigated and proposed. The production of humic-like acids (HLA) and fulvic-like acids (FLA) was observed in the frozen solution (-20 degrees C) whereas it was negligible in aqueous solution (20 degrees C). Inorganic nitrogen was transformed into organic nitrogen during the humification process. Mass spectrometry (MS) and elemental analyses, including pyrolysis-GC/MS and FT-ion cyclotron resonance/MS, showed that humification products (HLA and FLA) have chemical structures and compositions similar to nature humic substances. The enhanced humification reaction could be attributed to the freeze-concentration effect, whereby nitrite ions in the unfrozen grain boundary region are transformed into nitrosonium ions which oxidize phenols to phenolic radicals. Confocal Raman microscopy confirmed that catechol and nitrite ions are preferentially concentrated at the ice grain boundary and electron paramagnetic resonance spectroscopic analysis of catechol/nitrite solution detected the phenolic radicals only in frozen solution, not in aqueous solution. The freezing-induced generation of phenolic radicals should lead to the formation of humic-like substances through polymerization. This study identifies and proposes a new humic formation pathway that might work as a model abiotic "bottom-up" mechanism in frozen environmental conditions

Characterization of airborne endotoxin in personal exposure to fine particulate matter (PM2.5) and bioreactivity for elderly residents in Hong Kong

The heavy metals and bioreactivity properties of endotoxin in personal exposure to fine particulate matter (PM2.5) were characterized in the analysis. The average personal exposure concentrations to PM2.5 were ranged from 6.8 to 96.6 μg/m3. The mean personal PM2.5 concentrations in spring, summer, autumn, and winter were 32.1±15.8, 22.4±11.8, 35.3±11.9, and 50.2±19.9 μg/m3, respectively. There were 85 % of study targets exceeded the World Health Organization (WHO) PM2.5 threshold (24 hours). The mean endotoxin concentrations ranged from 1.086 ± 0.384–1.912 ± 0.419 EU/m3, with a geometric mean (GM) varied from 1.034 to 1.869. The concentration of iron (Fe) (0.008–1.16 μg/m3) was one of the most abundant transition metals in the samples that could affect endotoxin toxicity under Toll-Like Receptor 4 (TLR4) stimulation. In summer, the interleukin 6 (IL-6) levels showed statistically significant differences compared to other seasons. Spearman correlation analysis showed endotoxin concentrations were positively correlated with chromium (Cr) and nickel (Ni), implying possible roles as nutrients and further transport via adhering to the surface of fine inorganic particles. Mixed-effects model analysis demonstrated that Tumor necrosis factor-α (TNF-α) production was positively associated with endotoxin concentration and Cr as a combined exposure factor. The Cr contained the highest combined effect (0.205–0.262), suggesting that Cr can potentially exacerbate the effect of endotoxin on inflammation and oxidative stress. The findings will be useful for practical policies for mitigating air pollution to protect the public health of the citizens

Characterization of chemical components and cytotoxicity effects of indoor and outdoor fine particulate matter (PM2.5) in Xi'an, China

The chemical and cytotoxicity properties of fine particulate matter (PM2.5) at indoor and outdoor environment were characterized in Xi'an, China. The mass concentrations of PM2.5 in urban areas (93.29 similar to 96.13 mu g m(-3) for indoor and 124.37 similar to 154.52 mu g m(-3) for outdoor) were higher than suburban (68.40 mu g m(-3) for indoor and 96.18 mu g m(-3) for outdoor). The PM2.5 concentrations from outdoor environment due to fossil fuel combustion were higher than indoor environment. An indoor environment without central heating demonstrated higher organic carbon-to-elemental carbon (OC / EC) ratios and n-alkanes values that potentially attributed to residential coal combustion activities. The cell viability of human epithelial lung cells showed dose-dependent decrease, while nitric oxide (NO) and oxidative potential showed dose-dependent increase under exposure to PM2.5. The variations of bioreactivities could be possibly related to different chemical components from different sources. Moderate (0.4 0.6) correlations were observed between bioreactivities and elemental carbon (EC)/secondary aerosols (NO3-, SO42-, and NH4+)/heavy metals (Ni, Cu, and Pb). The findings suggest PM2.5 is associated with particle induced oxidative potential, which are further responsible for respiratory diseases under chronic exposure

Characteristics and cytotoxicity of indoor fine particulate matter (PM2.5) and PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Hong Kong

Organic components of fine particles, especially polycyclic aromatic hydrocarbons (PAHs), play an essential role in the toxicity of fine particulate matter (PM2.5). The chemical and bioreactive properties of PM2.5 in indoor environments were investigated from 2014 to 2016 in Hong Kong among 33 residential indoor environments. All analyzed components revealed higher concentrations in winter than in summer, except for organic carbon (OC). High molecular weight PAHs (4-6 rings) contributed higher total PAH compositions than low molecular weight PAHs (2-3 rings). The study results suggested that the major sources of indoor PM2.5 originated from outdoor vehicle emissions, indoor cooking activities, and incense burning. Cytotoxicity tests only revealed significant associations in winter. The cell viability demonstrated strong negative correlations between OC (r = - 0.8, p < 0.05), total PM2.5-bound PAHs (r = - 0.6, p < 0.05), and United States Environmental Protection Agency (US EPA) priority PAHs (r = - 0.7, p < 0.05). Cell lactate dehydrogenase (LDH) and 8-isoprostane were positively associated with OC (r = 0.8, p < 0.05; r = 0.7, p < 0.05), total PM2.5-bound PAH (r = 0.7, p < 0.05; r = 0.7, p < 0.05), and US EPA priority PAH (r = 0.6, p < 0.05; r = 0.5, p = 0.07) concentrations. IL-6 had the only positive association with OC (r = 0.5, p < 0.05). This study focused on indoor PM2.5 levels and the associated cytotoxicity in the absence of environmental tobacco smoke