Analysis of dust and noise exposure levels in the mining industry from the national surveillance program in 2019 / 中华劳动卫生职业病杂志

Objective: To understand the exposure level of dust and noise in the mining industry and provide data support for revising policy for the prevention and control of occupational diseases. Methods: In May 2022, Data was collected through the National Surveillance Program for Occupational Hazards in the Workplace. Descriptive analysis was conducted for dust and noise levels by industry type and enterprise size from 7, 679 enterprises in the mining industry among 29 provincial regions nationwide. Results: The enterprises in the mining industry included in the National Surveillance Program for Occupational Hazards in the Workplace are mainly small and micro, accounting for 47.97% (3684/7679) and 30.00% (230/7679) respectively. The industry is mainly compred of employers in the non-metallic ming and beneficiation industry, accounting for 50.25% (3859/7679). Among the enterprises with silica dust, coal dust, and noise hazards, the proportion of enterprises where total dust concentration and noise intensity exceed the standard is higher than 50%. 30% of the posts are with an exposure level of silica dust, coal dust, and noise that exceeds the standard. The exceedance rate and the median of the time-weighted average concentration of total coal dust among large and medium-sized enterprises are higher than those among small and micro-sized enterprises (P<0.05) . Conclusion: The dust and noise hazards in the mining industry are lower than in the past in China, but more than 25% of workers are still at a high risk of occupational pneumoconiosis and noise deafness. Therefore, intervention and surveillance strategies should be strengthened in the future.

Current status and research progress of occupational health monitoring in welding fume operations / 中华劳动卫生职业病杂志

Welding operations are widely present in the manufacturing production process, involving a large number of occupational groups, and are the key occupations where work injuries and occupational diseases occur in China. For different welding processes and welding materials, the content and focus of occupational health monitoring are different. At present, the item of occupational health examination in welding operation is in poor consistency with the on-site exposure of occupational hazard factors, and it is mainly concentrated in the stage of disease development, which can not reflect the early health damage caused by welding dust exposure in time. The emergence of biomarkers of welding dust can make up for this defect. Therefore, it is of great significance to describe the current situation of occupational health monitoring of welding dust and summarize the research progress of related biomarkers for the early prevention of diseases caused by welding dust and the practice of occupational health monitoring.

Study on risk factors of abnormal pulmonary function among dust-exposed workers and prediction model / 中华劳动卫生职业病杂志

Objective: To explore the influencing factors of abnormal pulmonary function in dust-exposed workers and establish the risk prediction model of abnormal pulmonary function. Methods: In April 2021, a total of 4255 dust exposed workers from 47 enterprises in 2020 were included in the study. logistic regression was used to analyze the influencing factors of abnormal pulmonary function in dust-exposed workers, and the corresponding nomogram prediction model was established. The model was evaluated by ROC curve, Calibrationpolt and decision analysis curve. Results: logistic regression analysis showed that age (OR=1.03, 95%CI=1.02~1.05, P<0.001) , physical examination type (OR=4.52, 95%CI=1.69~12.10, P=0.003) , dust type (Comparison with coal dust, Cement dust, OR=3.45, 95%CI=1.45~8.18, P=0.005, Silica dust (OR=2.25, 95%CI=1.01~5.03, P=0.049) , blood pressure (OR=1.63, 95%CI=1.22~2.18, P=0.001) , creatinine (OR=0.08, 95%CI=0.05~0.12, P<0.001) , daily exposure time (OR=1.06, 95%CI=1.10~1.12, P=0.034) and total dust concentration (OR=1.29, 95%CI=1.08~1.54, P=0.005) were the influencing factors of abnormal pulmonary function. The area under the ROC curve of risk prediction nomogram model was 0.764. The results of decision analysis curve showed that the nomogram model had reference value in the prevention and intervention of abnormal pulmonary function when the threshold probability exceeded 0.05. Conclusion: The accuracy ofthe nomogram model constructed by logistic regression werewell in predicting the risk of abnormal lung function of dust-exposed workers.

Correlation between intestinal and respiratory flora and their metabolites in a rat pneumoconiosis model / 中华劳动卫生职业病杂志

Objective: Differential flora and differential metabolites shared by the intestinal and respiratory tracts of rats were screened to analyze the possible role of changes in intestinal flora and metabolites in the progression of pneumoconiosis in rats. Methods: In April 2020, 18 SD rats were randomly divided into three groups (control group, coal mine dust group and silica group, 6 in each group) , rats in the coal mine dust group and silica group were perfused with 1 ml of 50 mg/ml coal mine well dust suspension and silica suspension by nontracheal exposure, respectively. While rats in the control group were perfused with an equal dose of sterilized normal saline. Twenty four weeks after dust staining, rat feces, throat swabs, and lung lavages were collected. 16SrDNA gene sequencing and UHPLC-QTOF-MS untargeted metabolomics were used to analyze the flora and metabolites in feces, throat swabs and lung lavage fluid of rats in each group, to screen for shared differential flora and shared differential metabolites in intestinal and respiratory tract, and the correlation analysis between the differential flora and metabolites was performed using Spearman's statistics. Results: Compared with the control group, a total of 9 species shared differential flora between intestinal and respiratory tract were screened at phylum level, and a total of 9 species shared differential genus between intestinal and respiratory tract were screened at genus level in the coal mine dust group, mainly Firmicutes, Actinobacteria, Streptococcus, Lactobacillus, etc. Compared with the control group, a total of 9 shared differential flora were screened at the phylum level, and a total of 5 shared differential genus were screened at the genus level in the silica group, mainly Proteobacteria, Actinobacteria, Allobactera, Mucilaginibacter, etc. Compared with the control group, a total of 7 shared differential metabolites were screened for up-regulation of Stigmatellin, Linalool oxide and Isoleucine-leucine in both intestinal and respiratory tract in the coal mine dust group. Compared with the control group , a total of 19 shared differential metabolites werescreened in the silica group, of which Diethanolamine, 1-Aminocyclopropanecarboxylic acid, Isoleucine-leucine, Sphingosine, Palmitic acid, D-sphinganine, 1, 2-dioleoyl-sn-glycero-3-phosphatidylcholine, and 1-Stearoyl-2-oleoyl-sn-glycerol 3-phosphocholine were up-regulated in both the intestinal and respiratory tract. Conclusion: There is a translocation of intestinal and respiratory flora in pneumoconiosis rats, and rats have an imbalance of lipid metabolism during the progression of pneumoconiosis.

Investigation and analysis of underground noise in Sichuan coal mines / 中华劳动卫生职业病杂志

Objective: To understand the harm degree of underground noise and provide basis for noise control. Methods: In November 2019, 13 typical coal mines in Sichuan Province were selected as the research objects, and a total of 1203 sites and 609 jobs of noise exposure were investigated. Results: The noise intensity P75 >80 dB (A) was measured. The noise intensity of the inspection place of the air compressor is >86 dB (A) , the noise intensity of the inspection place of the gas drainage and the operation place of the main fan is between 80-85 dB (A) . Conclusion: Besides the harm of dust, noise exposure should also be paid attention to, and the measures of sound absorption and sound insulation should be taken or personal protection should be strengthened.

Association of ambient fine particulate air pollution with hospitalization costs and stays for depression in China: a multicity analysis / 中华预防医学杂志

Objective: To explore the effect of fine particulate matter (PM2.5) pollution on depression hospitalization cost and length of stay in 57 cities of China. Methods: A total of 84 207 patients with depression in 57 cities of China from January 2013 to December 2017 were selected as the subjects. The demographic characteristics and hospitalization status of the patients were obtained from the database of basic medical insurance for urban workers and urban residents in China. The environmental exposure data of the same period were obtained from the national air quality real-time release platform of China Environmental Monitoring Station. A generalized additive model based on quasi-Poisson distribution was used to analyze PM2.5 exposure effect in each city, and the nonlinear mixing of moving average temperature, relative humidity and date was controlled by natural smooth spline function. Results: Among the included cities, southern cities accounted for 50.88% (29), and the number of female inpatients, hospitalization costs and hospitalization days accounted for 62.65%, 63.50% and 60.85% (42 735 cases, 567.78 million yuan and 1.14 million days, respectively). The proportion of hospitalized cases, hospitalization cost and length of stay in the age group of 40 to 64 years old were 59.15% (40 346 cases), 53.92% (482.15 million yuan) and 52.07% (0.98 million days), respectively. PM2.5 level was positively correlated with the number of hospitalized cases with depression, hospitalization cost and length of stay. When the 3-day moving average of PM2.5 exposure level increased by 10 μg/m3, the number of hospitalization cases increased by 0.64%. The attributed percentage (95%CI) of hospitalized cases, hospitalization costs and length of stay were 3.35% (0.57%-6.04%), 3.04% (0.52%-5.48%) and 3.07% (0.49%-5.56%), respectively. Subgroup analysis showed that the attributed percentage of hospitalization cases, hospitalization cost and length of stay to PM2.5 exposure ranged from 3.97% to 4.68%, 4.04% to 4.33% and 4.13% to 4.30% in northern China, male and cold season, respectively. Conclusion: PM2.5 exposure is associated with the increase of hospitalization cost and length of stay among Chinese urban population with depression.

Pollution characteristics, source analysis, and risk assessment of metal and metalloid in PM2.5 of Shijiazhuang city / 中华预防医学杂志

In 2020, the mass concentration of PM2.5 in Shijiazhuang urban area was(80.30±71.43)μg/m3. The Spearman correlation analysis between metals and metalloids showed that Sb with Cd, Pb, Ni, Se, Cd with Pb, Ni, Se, Pb with Ni, Se, Ni with Se, and Se with Tl were positively correlated, with a coefficient greater than 0.5. The main sources of metals and metalloids of PM2.5 were traffic emissions, fuel combustion, metal smelting and dust. The HQ values of Pb, Hg and Mn for each population were less than 1, with lower non-carcinogenic risk. The R values of carcinogenic risk of Ni and Cd in each population were less than 1×10-6, which could be acceptable risk level for the population. The R values of carcinogenic risk of As and Cr in different populations were between 1×10-6 and 1×10-4, with potential carcinogenic risk, particularly higher in adult males.

Spatial distribution of manganese concentration and load in street dust in Mexico City / Distribución espacial de las concentraciones y carga de manganeso en el polvo urbano de la Ciudad de México

Abstract: Objective: To obtain a first indication of the distribution and extent of manganese (Mn) contamination in Mexico City. Mn concentration and load in street dust were analyzed in order to reveal the most contaminated areas. Materials and methods: 482 samples of street dust were analyzed through inductively coupled plasma-optical emission spectroscopy. The contamination factor (CF), the geoaccumulation index (Igeo) and the spatial interpolations of the kriging indicator were calculated. Results: A slight influence of anthropogenic activities is detected on the Mn content of street dust. The highest levels of pollution by concentration (Igeo=uncontaminatedtomoderately contaminated) are grouped towards the city's north (industrial) and center (commercial and high traffic) areas. The areas with the highest Mn load were located towards the east and northwest areas (Igeo=moderately contaminated). Conclusions: These findings will serve as a baseline to assess future variations in Mn content in Mexico City's environment.

Resumen: Objetivo: Obtener una primera aproximación sobre la distribución espacial de la contaminación por manganeso (Mn) en la Ciudad de México. Se analizó la concentración y carga de Mn en el polvo de la calle para identificar las áreas más contaminadas. Material y métodos: 482 muestras de polvo de la calle fueron analizadas con espectroscopía de emisión por plasma de acoplamiento inductivo. Se calculó el factor de contaminación, índice de geoacumulación, y las interpolaciones espaciales del indicador kriging. Resultados: Existe una ligera influencia de actividades antropogénicas en el contenido de Mn del polvo de la calle. Los niveles más altos de contaminación por concentración (Igeo=no contaminado a moderadamente contaminado) se agruparon en el norte (industrial) y centro (comercial y de alto tráfico) de la ciudad. Las áreas con las cargas de Mn más altas estuvieron al este y noroeste (Igeo=moderadamente contaminado), donde había más polvo. Conclusiones: Estos resultados servirán como punto de referencia para evaluar variaciones futuras en el contenido de Mn en la Ciudad de México.

Evaluation of the concentration of allergens from mites in fur and households dust of dogs with atopic dermatitis / Avaliação da concentração de alérgenos provenientes de ácaros na pelagem e na poeira de domicílios de cães com dermatite atópica

This study evaluated the concentration of Der p 1, Der f 1 and Blo t 5 in the fur and households of 20 dogs with atopic dermatitis (AD) and 20 healthy dogs. The diagnosis of AD was clinical based on Favrot's criteria. Dust samples were collected with a domestic vacuum cleaner. For each site, 1m2 was vacuumed for 2 min. The samples were collected in separate filters, transferred into plastic containers, sealed and kept frozen until ELISA analysis. In the fur of atopic dogs the average concentration of Der p 1 was 0.25µg/g compared to 0.03µg/g in healthy dogs. In households with atopic dogs the highest concentrations of Der p 1 were found in carpets (2.18µg/g), followed by couches (1.53µg/g), beds (1.14µg/g), dogs' bed linen (0.64µg/g) and floors (0.14µg/g). The concentrations of Der p 1 on carpets, couches and beds were significantly higher than in atopic dogs' fur (p<0.05). There was no statistical difference when comparing the concentrations of Der f 1 and Blo t 5 in different environments of atopic dogs (p>0.05). The concentrations of Der p 1, Der f 1 and Blo t 5 were equivalent in atopic and non-atopic dog's households. Among the allergens studied, Der p 1 was the most commonly found, predominantly in carpets and couches.(AU)

O presente estudo avaliou a concentração de Der p 1, Der f 1 e Blo t 5, na pelagem e no ambiente domiciliar de cães com dermatite atópica (DA). Para tal, foram selecionados 20 cães com DA e 20 cães saudáveis, e seus domicílios. O diagnóstico de DA foi baseado nos critérios de Favrot. As amostras de poeira foram colhidas com um aspirador de pó doméstico. Para cada local de colheita, foi aspirado 1m2 por dois minutos. As amostras foram recolhidas em filtros separadamente, transferidas para envelopes plásticos, seladas e mantidas congeladas até serem analisadas pelo método de ELISA. Na pelagem dos cães com DA, a concentração média de Der p 1 foi de 0,25µg/g de poeira e nos cães saudáveis foi de 0,03µg/g. No ambiente de cães com DA, o Der p 1 foi encontrado em maior concentração média no tapete (2,18 µg/g), seguido pelo sofá (1,53g/g), cama (1,14µg/g) e roupa de cama dos cães (0,64µg/g) e chão (0,14µg/g). As concentrações de Der p 1 no tapete, sofá e cama dos cães foram significativamente maiores que na pelagem de cães com dermatite atópica (p<0,05). Enquanto que, não houve diferença estatística quando comparadas as concentrações de Der f 1 e Blo t 5 nos diferentes ambientes avaliados (p>0,05). As concentrações de alérgenos Der p 1, Der f 1 e Blo t 5 se equivaleram em ambientes de cães com DA e saudáveis. Entre os alérgenos estudados, o Der p 1 foi o mais comumente encontrado, prevalecendo no tapete e no sofá.(AU)

Relationship between chicken cellular immunity and endotoxin levels in dust from chicken housing environments

Hazardous biochemical agents in animal husbandry indoor environments are known to promote the occurrence of various illnesses among workers and animals. The relationship between endotoxin levels in dust collected from chicken farms and various immunological markers was investigated. Peripheral blood was obtained from 20 broiler chickens and 20 laying hens from four different chicken farms in Korea. Concentrations of total or respirable dust in the inside the chicken farm buildings were measured using a polyvinyl chloride membrane filter and mini volume sampler. Endotoxin levels in the dust were determined by the Limulus Amebocyte Lysate Kinetic method. Interferon-gamma production by peripheral blood mononuclear cells stimulated with concanavalin A was significantly lower in broilers or layers from the farms with higher endotoxin concentrations than the chickens from the farms with lower endotoxin levels. An opposite pattern was observed for plasma cortisol concentrations with higher cortisol levels found in chickens from the farms with higher endotoxin levels. When peripheral lymphocytes were examined, the percentage of CD3-Ia+ B cells was lower in layers from farms with higher endotoxin levels than those from locations with lower endotoxin levels. Overall, these results suggest a probable negative association between dust endotoxin levels and cell-mediated immunity in chickens.

Skin reactivity to allergens in Rabigh area, Kingdom of Saudi Arabia

This study determined the pattern of skin prick test reactivity to allergens in patients with airway allergy residing in Rabigh Area, based on data analysis of skin prick test results. Skin prick tests of 160 Saudi attended Al Nakheel Polyclinic between July, 2012 and April, 2013. Allergen extracts set was used to test them. Out 160 patients, 114 [71%] reacted to one or more allergens, who were 73 [64%] adults and 41 [36%] children. The majority of adults [17.8%] reacted to six allergens and children [19.5%] reacted to five ones. The most frequently reacting allergen was house dust mites followed by Candida albicans then Cladosporium spp. The maximum number of positive tests per patients was 13 in adults, compared to 10 in children. A significantly higher proportion of adults were reacting to house dust mites, Aspergillus and Penicillium. Sensitivity to allergens was common in patients with airway allergy residing in Rabigh area

Exposición infantil al plomo en sitios contaminados / Children exposure to lead in contaminated sites

OBJETIVO: Determinar el grado de la exposición infantil al plomo en diversos tipos de sitios contaminados. MATERIAL Y MÉTODOS: El estudio se realizó de junio 2008 a diciembre 2009 en cuatro sitios de México: metalúrgica de Ávalos, Chihuahua.; metalúrgica de Morales, San Luis Potosí (SLP); zona alfarera en La Trinidad, Tlaxcala, y sitio minero en Cedral, SLP. Se cuantificó plomo en polvo y se realizó un biomonitoreo humano en niños de la comunidad. RESULTADOS: Los valores obtenidos de plomo en polvo exterior superaron el límite establecido de 400 mg/kg para suelos residenciales en un intervalo de valores para los cuatro sitios de 62 a 5 187 mg/kg. En cuanto al monitoreo biológico, todas las poblaciones presentaron valores extremos, desde los 22 µg/dL en Cedral, 31 µg/dL en Morales, y 32 µg/dL en Ávalos, hasta los 52 µg/dL en La Trinidad. Es importante señalar que encontramos una correlación positiva y significativa entre los valores de plomo en polvo y plomo en sangre en todos los sitios de estudio (p<0.001). CONCLUSIÓN: Estos sitios son un ejemplo de los riesgos en salud relacionados con la exposición a plomo en México; por consiguiente, se requiere de un programa nacional de salud pública dirigido a reducir la exposición a este metal en poblaciones vulnerables.

OBJECTIVE: To assess the exposure to lead in children living in various types of contaminated sites. MATERIALS AND METHODS: The study was conducted from June 2008 to December 2009 at four sites in Mexico: Avalos metallurgical, Chihuahua; Morales metallurgical, San Luis Potosí (SLP); Trinidad pottery area, Tlaxcala and Cedral mine site, SLP. These sites contain different sources of lead. The metal levels were quantified in outdoor dust and in peripheral blood of children. RESULTS: Lead dust concentrations exceed the National Guidelines for residential soils (400 mg/kg) in a range of values for the four sites from 62 to 5 187 mg/kg. Regarding biological monitoring, the studied children showed maximum lead blood levels of 22 µg/dL in Cedral, 31 µg/dL in Morales, 32 µg/dL in Avalos, and 52 µg/dL in Trinidad. It is important to mention that in all the studied sites, a significative positive correlation was found between blood lead levels and the lead concentrations in dust. CONCLUSION: These sites are an example of the health risks related to lead exposure in Mexico; therefore, there is an urgent need for a national public health program aimed at reducing lead exposure in vulnerable populations.

Lead exposure among the general population of Duhok governorate, Kurdistan region, Iraq

This study was carried out to establish baseline data on lead exposure in a sample of the general population from Duhok governorate, Iraq in 2011. A cross-sectional study was made of blood lead levels of 820 individuals and of dust and of air lead levels in urban, suburban and rural residential areas. Mean blood lead [BPb] value in the overall sample was 7.3 [SD 2.8] microg/dL, range 1.6-17.0 microg/dL; significant differences were found with respect to age, area of residence, altitude and distance from a gasoline generator. The prevalence of toxic levels of lead [BPb > 10 microg/dL] was 22.8% overall and 2.4% in children. People living in suburban areas [39.7%] and < 50 m from a gasoline generator [93.1%] were exposed to high environmental lead levels. A linear relationship was found between BPb and air lead levels [r= 0.8]. While lead exposure does not constitute a great health problem for adults in our community, 2.4% of the children had toxic lead levels and measures to reduce exposure to environmental heavy metals should be considered

The hammock: a reservoir of allergens

INTRODUCTION: Asthma affects approximately 10 percent of the world's population. Sensitization to allergens is an important risk factor, and exposure to allergens is associated with disease severity. METHODS: We performed skin tests to evaluate allergen sensitization to mites, cockroaches, cats, dogs, and molds in 73 asthmatic patients. Enzyme Linked Immunosorbent Assay was used to assay the mite and cockroach allergens found in dust from the bedding, hammocks, bedroom floors, living rooms, and kitchens of 29 patients and 14 controls. RESULTS: Fifty patients (68.5 percent) had positive skin test responses. There were positive responses to D. pteronyssinus (52.0 percent), B. tropicalis (53.4 percent), T. putrescentiae (15.0 percent), E. maynei (12.3 percent), L. destructor (8.2 percent), B. germanica (20.5 percent), P. americana (21.9 percent), Felis catus (10.9 percent), C. herbarium (2.7 percent), A. alternata (4.1 percent), and P. notatun (1.3 percent). The exposure to mite and cockroach allergens was similar in the patients and the controls. The Dermatophagoides pteronyssinus Group 1 levels were highest in the beds and hammocks. The Blattella germanica Group 1 levels were highest in the kitchens, living rooms and hammocks. DISCUSSION: The positive skin tests to mites, cockroaches and cats were consistent with previous studies. D pteronyssinus was the most prevalent home dust mite, and hammocks were a source of allergens. To improve asthma prophylaxis, it is important to determine its association with mite allergen exposure in hammocks.

Características biogeoquímicas da interação atmosfera - criosfera na Antártica ocidental / Biogeochemical characteristics of the interaction atmosphere - cryosphere in the occidental Antarctic

Atualmente a comunidade científica discute as diferenças de padrões climáticos entre o leste e o oeste antártico. Enquanto de forma geral observa-se instabilidade no setor oeste, o clima da antártica oriental demonstra relativa estabilidade climática. Abordando este contexto, neste estudo analisamos dois testemunhos de gelo recente de duas regiões com características climáticas diferentes do continente Antártico. No Platô Detroit situado na Península Antártica (64o10'S/060o0'O), analisamos a variabilidde de Black Carbon (BC) ao longo de 20 metros de neve. O BC encontrado na Península Antártica apresentou baixas concentrações comparáveis as encontradas no gelo do Artico período pré-industrial. Nossos resultados sugerem que sua variabilidade corresponde à sazonalidade dos períodos de queimada nos continentes do Hemisfério Sul. No interior do continente Antártico, analisamos o particulado em geral por um processo de microanálise ao longo de um testemunho de 40 metros extraído em Mont Johns (79o55'S/094o23'O). Encontramos uma tendência negativa na deposição de poeira mineral (AISi) entre 1967 e 2007. Nossos resultados sugerem que esta tendência seja resultado de um crescente isolamento dos ventos ao redor da Antártica. Este aumento na intensidade dos ventos reflete por sua vez o resfriamento da alta atmosfera no centro antártico causado pela depleção da camada de ozônio na região. Adicionalmente, amostras de diferentes microambientes de Patriot Hills (80o18'S/081o21'O) foram coletadas de maneira asséptica para análise microbiológica. As amostras foram cultivadas em meio R2 e paralelamente o DNA total extraído foi sequenciado pela técnica de pirosequenciamento. Os resultados preliminares desta análise mostram grande riqueza de espécies dos mais variados grupos. Os resultados deste trabalho caracterizam três diferentes parâmetros relacionados a deposição atmosférica em duas áreas do continente antártico pouco exploradas e de grande interesse científico...

The antarctic ice cap stores paleoclimatological information within layers of snow and ice. Antarctic ice has revealed the higher resolution paleoclimactic database for the last 800 kyr. Atmospheric transport plays a fundamental role on the composition and sources of particulate matter found in the Antarctic ice. It has been related to several climatic processes that changes the quantity and quality of exogenous aerosols reaching Antarctica. Therefore, studies of the particulate matter deposits along the snow/ice layers may suggest changes on atmospheric transport patterns. This work, analyze two recent ice cores from two climatic distinct regions of the Antarctic continent. One retrieved from Detroit Plateau/Antarctic Peninsula (64o10'S/060o0'W), in which we have analyze Black Carbon (BC) deposition and variability along 20 meters of snow. BC found in the Antarctic Peninsula showed low concentrations (varing between 0,014 and 3,733ppb), comparable to the concentrations found on Arctic ice dated from before the industrial revolution period. Our results suggest that peaks of BC detected correspond, mostly, to biomass burning seasons in the South Hemosphere, not speficically from South America. The second one, of 40 m, was retrieved from Central-West Antarctica, Mont Johns (79o55'S/094o23'W), in which we analyzed the mineral dust abundance thought M.E.V. - E.D.X. technique. In this study we found negative trends in mineral dust (inferred from Fe, Ti and AISi) deposition between 1967 and 2007, in contrast to similar works in Sub-antarctic regions. We demonstrate that this trend is a consequence of the persistent "atmospheric isolation" that encloses the Central and East Antarctic regions due to the increasing winds around Antarctica within this period. It has been documented that westerlies intensification reflect the upper atmosphere cooling above Central Antarctica caused by the stratospherical ozone layer depletion. As part of the polar site...

Mineralogical composition of khamasin wind dust at Assiut, Eygpt

The present study investigated the mineralogical composition of the deposited dust from Khamasin wind on the agricultural soils at Assiut city through April 2008 and 2009. Five sites were chosen between the fringes of eastern and western deserts throughout the Nile valley. Wood boxes [dimensions of 1xlm] were put in the selected sites and precipitated dust was collected from each box after the finish of Khamasin storms in the two years. The quantity, pH and EC were determined for the collected Khamasin dust. The mineral particles of these dusts were examined by the scanning electron microscope [SEM] and the X-ray analysis. The obtained results revealed some variation in the dust quantity of Khamasin wind in the year of 2008 and 2009. The quantity of the collected bulk samples of the Khamasin dust varied from site to another in both 2008 and 2009 years. The highest amounts in both years are recorded in the sites of the eastern side of the Nile valley that faraway from the western desert where the Khamasin wind come. The mean values of dust EC and pH were low and similar in both years of 2008 and 2009. The Scanning electron microscope photomicrographs showed that the grain sizes of Khamasin dust in the sites located in the interference zone of Nile valley with the eastern desert were finer than those in site located in the western side of the Nile river. Generally, relatively large angular to subangular grains, larger amount of very Fine grains with more oblate particle and spherical particles with differences in size as well as particles with irregular shapes in Khamasin dust of 2008 and 2009 years. Semi-quantitative measurements of the identified minerals in the Khamasin dust of 2008 year have shown the order of quartz >k-feldspar>calcite> magnetite >epidote> anhydrite > garnet > augite> tourmaline > zircon > ilmenite > plagioclase > goethite > actinolite > hematite. However, the minerals in the Khamasin dust of 2009 year could be ordered as quartz >k-feldspar>calcite>epidote> magnetite > tourmaline > anhydrite > augite > plagioclase >Imenite>rutile> hematite > garnet >actinolite. There was no general trend for distribution of these minerals throughout the studied sites. From a qualitative point of view, most of the sites have the same mineralogical composition. Comparison of the mineralogical compositions of mineral dusts at the five sites, revealed certain quantitative differences

[Evaluation of the rate of occupational exposure to wheat flour dust in wheat flour mill factories in Hamedan]

Wheat flour is a complex organic particle containing an array of different allergic and antigenic components. Exposure to flour dust may result in a variety of respiratory problems such as allergic responses, occupational asthma and allergic rhinitis. The aim of the present study was to assess the concentration of inhalable dust and gliadin of flour dust as an important wheat flour allergen and to determine the relationship between concentrations of flour dust and that of gliadin in the air breathed by the workers in different workstations of wheat flour mill factories. This was a cross-sectional descriptive study. 64 air samples were collected by means of universal air sampling pumps. Inhalable flour dust density was measured by gravimetric method and flour dust gliadin concentration was determined by enzyme-linked immunosorbent assay [ELISA]. The mean flour dust density was higher than that of permissible limit in all wheat flour mill factories [1.64-4.68 mg/m3] and showed a significant positive relation with gliadin concentration [R2 = 0.708, p<0.05] in all factories. In addition, Inhalable dust density and gliadin concentration have been different in different stations of the factories and were highest in flour packing workstation. This study revealed the density of Inhalable flour dust had been higher than the level of permissible limit [0.5 gr/m3] and the workers in Hamadan flour mills are exposed to a dangerous level of flour dust, and inhale a high level of gliadin in all flour packing unites of the factories in Hamedan

Effect of an Air Cleaner with Electrostatic Filter on the Removal of Airborne House Dust Mite Allergens

PURPOSE: The effects of air cleaners on the removal of airborne indoor allergens, especially house dust mites (HDM), are still controversial. The objective of this study is to evaluate the effect of an air cleaner with an electrostatic filter on the removal of airborne mite allergens. MATERIALS AND METHODS: A dried HDM culture medium that contained mite body particles and excretions was dispersed in a chamber equipped with an electrostatic air cleaner. The number of airborne particles was recorded continuously by a dust spectrometer for 60 minutes. Airborne particles in the chamber were collected on a sampling filter at a flow rate of 10 L/min and the Der f 1 concentration in the filter extracts was measured by two-site ELISA. RESULTS: The air cleaner efficiently removed airborne HDM particles. The air cleaner removed airborne HDM particles (size 2-12.5 microm) 11.4 +/- 2.9 fold (cleaner operating for 15 minutes), 5.4 +/- 0.7 fold (cleaner operating for 30 minutes), and 2.4 +/- 0.2 fold (cleaner operating for 60 minutes) more than the removal of HDM particles by natural settle down. Removal kinetics differed according to the particle size of the airborne particles. The air cleaner decreased the concentration of Der f 1 in the extraction of airborne particles collected on the air sampling filter by 60.3%. CONCLUSION: The electrostatic air cleaner can remove airborne HDM allergens and may be useful as a supplementary environmental control tool for HDM sensitized respiratory allergic patients.

Prevalence of potentially pathogenic free-living amoebae from Acanthamoeba and Naegleria genera in non-hospital, public, internal environments from the city of Santos, Brazil

Acanthamoeba and Naegleria species are free-living amoebae (FLA) found in a large variety of natural habitats. The prevalence of such amoebae was determined from dust samples taken from public non-hospital internal environments with good standards of cleanliness from two campuses of the same University in the city of Santos (SP), Brazil, and where young and apparently healthy people circulate. The frequency of free-living amoebae in both campuseswas 39 percent and 17 percent respectively, with predominance of the genus Acanthamoeba. On the campus with a much larger number of circulating individuals, the observed frequency of free-living amoebae was 2.29 times larger (P< 0.00005). Two trophozoite forms of Naegleria fowleri, are the only species of this genus known to cause primary amoebian meningoencephalitis, a rare and non-opportunistic infection. We assume that the high frequency of these organisms in different internal locations represents some kind of public health risk.

Ácaros da família Cheyletidae (Acari: Actinedida) em ecossistema domiciliar no município de Juiz de Fora, estado de Minas Gerais, Brasil / Mites from Cheyletidae family (Acari: Actinedida) in domiciles in Juiz de Fora municipality, Minas gerais State, Brazil

A presença de ácaros da família Cheyletidae tem sido relatada na poeira domiciliar. Esses ácaros estão associados a doenças cutâneas em animais e hmanos, nesses últimos, sua presença tem sido pouco valorizada na prática clínica. O objetivo deste estudo foi avaliar a prevalência de ácaros da família Cheyletidae no ecossistema domiciliar. Tendo como amostra 160 casas do município de Juiz de Fora, estado de Minas Gerais, Brasil, o estudo evidenciou que 13 (0,85por cento) dos ácaros encontrados eram da família Cheyletidae, com 6,9por cento de prevalência de domicílios positivos para ácaros desta família. Cheyletus malaccensis, Ker bakeri, Cheyletus fortis, Cheletonella vespertillionis e Cheletonella caucasica foram as espécies identificadas. A diversidade de espécies encontradas em locais de íntimo contato com humanos e o relato de dermatites a elas associadas mostram a necessidade de estudos sobre esta etiologia.