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Sample records for airborne endotoxin exposure

  1. Exposure to airborne endotoxins among sewer workers: an exploratory study.

    PubMed

    Duquenne, Philippe; Ambroise, Denis; Görner, Pierre; Clerc, Frédéric; Greff-Mirguet, Guylaine

    2014-04-01

    Exploratory bioaerosol sampling was performed in order to assess exposure to airborne endotoxins during sewer work. Personal samples were collected in underground sewer pipes using 37-mm closed-face cassettes containing fibreglass filters (CFC-FG method) or polycarbonate filters (CFC-PC method). Endotoxins were quantified using the limulus amoebocyte lysate assay. Concentrations of airborne endotoxins at sewer workplaces (16-420 EU m(-3)) were higher than those measured outside the sewer network (0.6-122 EU m(-3)). Sewer worker exposure to airborne endotoxins depended on the workplace and on the tasks. Exposure levels were the highest for tasks involving agitation of water and matter, especially for 'chamber cleanup' and 'pipes cleanup' with a high-pressure water jet. Airborne endotoxin levels at the workplace tended to be higher when CFC-FG was used as the sampling method rather than CFC-PC. The adjusted mean of the measured concentrations for CFC-PC represents 57% of the mean observed with CFC-FG. The number of samples collected in the descriptive study was too low for drawing definitive conclusions and further exposure investigations are needed. Therefore, our exploratory study provides new exposure data for the insufficiently documented sewer working environment and it would be useful for designing larger exposures studies.

  2. Indoor Pollutant Exposures Modify the Effect of Airborne Endotoxin on Asthma in Urban Children

    PubMed Central

    Hansel, Nadia N.; Aloe, Charles; Schiltz, Allison M.; Peng, Roger D.; Rabinovitch, Nathan; Ong, Mary Jane; Williams, D’Ann L.; Breysse, Patrick N.; Diette, Gregory B.; Liu, Andrew H.

    2013-01-01

    Rationale: The effect of endotoxin on asthma morbidity in urban populations is unclear. Objectives: To determine if indoor pollutant exposure modifies the relationships between indoor airborne endotoxin and asthma health and morbidity. Methods: One hundred forty-six children and adolescents with persistent asthma underwent repeated clinical assessments at 0, 3, 6, 9, and 12 months. Home visits were conducted at the same time points for assessment of airborne nicotine, endotoxin, and nitrogen dioxide (NO2) concentrations. The effect of concomitant pollutant exposure on relationships between endotoxin and asthma outcomes were examined in stratified analyses and statistical models with interaction terms. Measurements and Main Results: Both air nicotine and NO2 concentrations modified the relationships between airborne endotoxin and asthma outcomes. Among children living in homes with no detectable air nicotine, higher endotoxin was inversely associated with acute visits and oral corticosteroid bursts, whereas among those in homes with detectable air nicotine, endotoxin was positively associated with these outcomes (interaction P value = 0.004 and 0.07, respectively). Among children living in homes with lower NO2 concentrations (<20 ppb), higher endotoxin was positively associated with acute visits, whereas among those living in homes with higher NO2 concentrations, endotoxin was negatively associated with acute visit (interaction P value = 0.05). NO2 also modified the effect of endotoxin on asthma symptom outcomes in a similar manner. Conclusions: The effects of household airborne endotoxin exposure on asthma are modified by coexposure to air nicotine and NO2, and these pollutants have opposite effects on the relationships between endotoxin and asthma-related outcomes. PMID:24066676

  3. Exposure to airborne microorganisms and endotoxin in herb processing plants.

    PubMed

    Dutkiewicz, J; Krysińska-Traczyk, E; Skórska, C; Sitkowska, J; Prazmo, Z; Golec, M

    2001-01-01

    Microbiological air sampling was performed in two herb processing plants located in eastern Poland. Air samples for determination of the levels of bacteria, fungi, dust and endotoxin were collected at 14 sites during cleaning, cutting, grinding, sieving, sorting and packing of 11 kinds of herbs (nettle, caraway, birch, celandine, marjoram, mint, peppermint, sage, St. John's wort, calamus, yarrow), used for production of medications, cosmetics and spices. It was found that processing of herbs was associated with a very high pollution of the air with bacteria, fungi, dust and endotoxin. The numbers of microorganisms (bacteria and fungi) in the air of herb processing plants ranged within 40.6-627.4 x 10(3) cfu/m3 (mean +/- S.D = 231.4 +/- 181.0 x 10(3) cfu/m3). The greatest concentrations were noted at the initial stages of production cycle, during cleaning, cutting and grinding of herbs. The numbers of airborne microorganisms were also significantly (p<0.0001) related to the kind of processed herb, being the greatest at processing marjoram, nettle, yarrow and mint. The values of the respirable fraction of airborne microflora in the examined facilities varied within a fairly wide range and were between 14.7-67.7%. The dominant microorganisms in the air of herb processing plants were mesophilic bacteria, among which endospore-forming bacilli (Bacillus spp.) and actinomycetes of the species Streptomyces albus were most numerous. Among Gram-negative bacteria, the most common was endotoxin-producing species Alcaligenes faecalis. Altogether, 37 species or genera of bacteria and 23 species or genera of fungi were identified in the air of herb processing plants, of these, 11 and 10 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of dust and bacterial endotoxin in the air of herb processing plants were large with extremely high levels at some sampling sites. The concentrations of airborne dust ranged within 3

  4. Exposure to airborne microorganisms and endotoxin in herb processing plants.

    PubMed

    Dutkiewicz, J; Krysińska-Traczyk, E; Skórska, C; Sitkowska, J; Prazmo, Z; Golec, M

    2001-01-01

    Microbiological air sampling was performed in two herb processing plants located in eastern Poland. Air samples for determination of the levels of bacteria, fungi, dust and endotoxin were collected at 14 sites during cleaning, cutting, grinding, sieving, sorting and packing of 11 kinds of herbs (nettle, caraway, birch, celandine, marjoram, mint, peppermint, sage, St. John's wort, calamus, yarrow), used for production of medications, cosmetics and spices. It was found that processing of herbs was associated with a very high pollution of the air with bacteria, fungi, dust and endotoxin. The numbers of microorganisms (bacteria and fungi) in the air of herb processing plants ranged within 40.6-627.4 x 10(3) cfu/m3 (mean +/- S.D = 231.4 +/- 181.0 x 10(3) cfu/m3). The greatest concentrations were noted at the initial stages of production cycle, during cleaning, cutting and grinding of herbs. The numbers of airborne microorganisms were also significantly (p<0.0001) related to the kind of processed herb, being the greatest at processing marjoram, nettle, yarrow and mint. The values of the respirable fraction of airborne microflora in the examined facilities varied within a fairly wide range and were between 14.7-67.7%. The dominant microorganisms in the air of herb processing plants were mesophilic bacteria, among which endospore-forming bacilli (Bacillus spp.) and actinomycetes of the species Streptomyces albus were most numerous. Among Gram-negative bacteria, the most common was endotoxin-producing species Alcaligenes faecalis. Altogether, 37 species or genera of bacteria and 23 species or genera of fungi were identified in the air of herb processing plants, of these, 11 and 10 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of dust and bacterial endotoxin in the air of herb processing plants were large with extremely high levels at some sampling sites. The concentrations of airborne dust ranged within 3

  5. LOW-DOSE AIRBORNE ENDOTOXIN EXPOSURE ENHANCES BRONCHIAL RESPONSIVENESS TO INHALED ALLERGEN IN ATOPIC ASTHMATICS

    EPA Science Inventory

    Endotoxin exposure has been associated with both protection against development of TH2-immune responses during childhood and exacerbation of asthma in persons who already have allergic airway inflammation.1 Occupational and experimental inhalation exposures to endotoxin have been...

  6. Exposure to airborne microorganisms, dust and endotoxin during processing of peppermint and chamomile herbs on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    cultivating peppermint are exposed during processing of this herb to large concentrations of airborne microorganisms, dust and endotoxin posing a risk of work-related respiratory disease. The exposure to bioaerosols during processing of chamomile is lower; nevertheless, peak values create a respiratory risk for exposed farmers. PMID:16457486

  7. Predictors of airborne endotoxin concentrations in inner city homes.

    PubMed

    Mazique, D; Diette, G B; Breysse, P N; Matsui, E C; McCormack, M C; Curtin-Brosnan, J; Williams, D L; Peng, R D; Hansel, N N

    2011-05-01

    Few studies have assessed in home factors which contribute to airborne endotoxin concentrations. In 85 inner city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36-42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483

  8. Longitudinal study of dust and airborne endotoxin in the home.

    PubMed

    Park, J H; Spiegelman, D L; Burge, H A; Gold, D R; Chew, G L; Milton, D K

    2000-11-01

    To characterize the seasonal variability of endotoxin levels, we measured endotoxin in dust from the bed, bedroom floor, and kitchen floor in 20 homes, and in air from the bedroom in 15 of the homes. All homes were located in the greater Boston, Massachusetts, area and were sampled each month from April 1995 to June 1996. Outdoor air was collected at two locations. We found greater within-home than between-home variance for bedroom floor, kitchen floor, and airborne endotoxin. However, the reverse was true for bed dust endotoxin. Thus, studies using single measurements of dust endotoxin are most likely to reliably distinguish between homes if bed dust is sampled. Dust endotoxin levels were not significantly associated with airborne endotoxin. Airborne endotoxin was significantly (p = 0. 04) and positively associated with absolute humidity in a mixed-effect model adjusting for a random home effect and fixed effect of sampling month and home characteristics. This finding implies that indoor humidity may be an important factor controlling endotoxin exposure. We found a significant (p < 0.05) seasonal effect in kitchen floor dust (spring > fall) and bedroom airborne endotoxin (spring > winter), but not in the other indoor samples. We found significant seasonal pattern in outdoor airborne endotoxin (summer > winter). PMID:11102291

  9. Exposure to airborne microorganisms, dust and endotoxin during processing of valerian roots on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during various stages of valerian (Valeriana officinalis) roots processing by herb farmers and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 15 farms owned by valerian cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the air showed a marked variability and were within a range of 0.95-7,966.6 x 10(3) cfu/m (3). Though median was relatively low (10.75 x 10(3) cfu/m (3)), on 4 farms the concentrations exceeded the level of 10(5) cfu/m (3) and on 1 farm the level of 10(6) cfu/m (3). During the processing of valerian roots, distinct changes could be observed in the composition of airborne microflora. In the first stages of processing, the freshly dug and washed roots until shaking in the drying room, the most numerous were Gram-negative bacteria of the family Pseudomonadaceae (mostly Stenotrophomonas maltophilia, Pseudomonas chlororaphis and Pseudomonas fluorescens). After drying, the dominant organisms were thermo-resistant endospore-forming bacilli (Bacillus spp.) and fungi, among which prevailed Aspergillus fumigatus. Altogether, 29 species or genera of bacteria and 19 species or genera of fungi were identified in the farm air during valerian processing, of these, 10 and 12 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of airborne dust and endotoxin on the examined farms were very large and ranged from 10.0-776.7 mg/m (3), and from 0.15-24,448.2 microg/m (3), respectively (medians 198.3 mg/m (3) and 40.48 microg/m (3)). In conclusion, farmers cultivating valerian could be exposed during processing of valerian roots to large concentrations of airborne microorganisms, dust and endotoxin posing a risk of work

  10. Exposure to airborne culturable microorganisms and endotoxin in two Italian poultry slaughterhouses.

    PubMed

    Paba, Emilia; Chiominto, Alessandra; Marcelloni, Anna Maria; Proietto, Anna Rita; Sisto, Renata

    2014-01-01

    Even if slaughterhouses' workers handle large amounts of organic material and are potentially exposed to a wide range of biological agents, relatively little and not recent data are available. The main objective of this study was to characterize indoor concentrations of airborne bacteria, fungi, and endotoxin mod = Im (endotoxin∼Gram-negative*plant*filter) in two Italian poultry slaughterhouses. Air samples near air handling units inlets were also collected. Since there are not standardized protocols for endotoxin sampling and extraction procedures, an additional aim of the study was to compare the extraction efficiency of three different filter.. The study was also aimed at determining the correlation between concentrations of Gram-negative bacteria and endotoxin. In Plant A bacterial levels ranged from 17.5 to 2.6×10(3) CFU/m3. The highest concentrations were observed in evisceration area of chickens, between the automatic detachment of the neck and washing offal, and near birds coupling before hair-chilling. The highest mean value of Gram-negative (266.5 CFU/m3) was found near the washing offal of turkeys. In Plant B bacterial concentration ranged from 35 to 8×10(3) CFU/m3. The highest concentration. with the highest value of Gram-negative (248 CFU/m3), was found after defeathering. Fungal concentrations were overall lower than those found for bacteria (range: 0-205 CFU/m3 in Plant A and 0-146.2 CFU/m3 in Plant B). The microbial flora was dominated by Gram-negative and coagulase-negative staphylococci for bacteria and by species belonging to Cladosporium, Penicillium and Aspergillus genera for molds. The highest endotoxin concentrations were measured in washing offal for Plant A (range: 122.7-165.9 EU/m3) and after defeathering for Plant B (range: 0.83-38.85 EU/m3). In this study airborne microorganisms concentrations were lower than those found in similar occupational settings and below the occupational limits proposed by some authors. However, these

  11. Optimizing the extraction, storage, and analysis of airborne endotoxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While the Limulus amebocyte lysate (LAL) assay is part of most procedures to assess airborne endotoxin exposure, there is no universally agreed upon standard procedure. The purpose of this study was to fill in additional knowledge gaps with respect to the extraction, storage, and analysis of endotox...

  12. Exposure to inhalable dust and endotoxins in agricultural industries.

    PubMed

    Spaan, Suzanne; Wouters, Inge M; Oosting, Isabella; Doekes, Gert; Heederik, Dick

    2006-01-01

    Endotoxin is a well-known bacterial toxin that causes several health effects. Animal faeces and plant materials contaminated with bacteria have been identified as important determinants of organic dust related endotoxin exposure. Although high exposure to organic dust and endotoxins has been described regularly in agricultural industries, a detailed overview of levels of airborne exposure to endotoxins in the agricultural industry, as well as a systematic comparison between several specific branches using the same exposure assessment protocols are lacking. In this study, personal endotoxin exposure in a broad spectrum of agricultural industries was investigated and possible determinants of exposure were explored. 601 personal inhalable dust samples were taken in 46 companies of three agricultural industrial sectors: grains, seeds and legumes sector (GSL), horticulture sector (HC) and animal production sector (AP), with 350 participating employees. Dust and endotoxin levels were determined gravimetrically and by using the Limulus Amoebocyte Lysate (LAL) assay, respectively. Basic descriptive analysis and elaborate analysis of variance were performed. Mean exposure levels were high, with large differences between sectors and between companies within the sectors. Highest dust and endotoxin exposures were found in companies of the GSL sector. In all three sectors exposure was higher in the primary production part compared to the (industrial) products processing part of the sector. The Dutch proposed health based occupational exposure limit (50 EU m(-3)) and temporary legal limit (200 EU m(-3)) for endotoxin were often exceeded. Differences in exposure between workers were larger than the day-to-day variability. Identified determinants increasing exposure levels were company, dustiness of the product and contact with animals/faeces. 'Wet' processes resulted in less dusty working environments and thus lowered endotoxin exposure. Overall, exposure to endotoxins over the

  13. Airborne endotoxin in fine particulate matter in Beijing

    NASA Astrophysics Data System (ADS)

    Guan, Tianjia; Yao, Maosheng; Wang, Junxia; Fang, Yanhua; Hu, Songhe; Wang, Yan; Dutta, Anindita; Yang, Junnan; Wu, Yusheng; Hu, Min; Zhu, Tong

    2014-11-01

    Endotoxin is an important biological component of particulate matter (PM) which, upon inhalation, can induce adverse health effects, and also possibly complicate the diseases in combination with other pollutants. From 1 March 2012 to 27 February 2013 we collected air samples using quartz filters daily for the quantification of airborne endotoxin and also fine PM (PM2.5) in Beijing, China. The geometric means for endotoxin concentration and the fraction of endotoxin in PM were 0.65 EU/m3 (range: 0.10-75.02) and 10.25 EU/mg PM2.5 (range: 0.38-1627.29), respectively. The endotoxin concentrations were shown to vary greatly with seasons, typically with high values in the spring and winter seasons. Temperature and relative humidity, as well as concentrations of sulfur dioxide and nitrogen oxides were found to be significantly correlated with airborne endotoxin concentrations (p < 0.05). Additionally, positive correlations were also detected between endotoxin concentrations and natural sources of Na+, K+, Mg2+, and F-, while negative correlations were observed between endotoxin concentrations and anthropogenic sources of P, Co, Zn, As, and Tl. Oxidative potential analysis revealed that endotoxin concentrations were positively correlated with reactive oxygen species (ROS), but not dithiothreitol (DTT) of PM. This study provided the first continuous time series of airborne endotoxin concentrations in Beijing, and identifies its potential associations with atmospheric factors. The information developed here can assist in the assessment of health effects of air pollution in Beijing.

  14. Evaluation of a low-cost electrostatic dust fall collector for indoor air endotoxin exposure assessment.

    PubMed

    Noss, Ilka; Wouters, Inge M; Visser, Maaike; Heederik, Dick J J; Thorne, Peter S; Brunekreef, Bert; Doekes, Gert

    2008-09-01

    Exposure to endotoxin in home environments has become a key issue in asthma and allergy research. Most studies have analyzed floor or mattress dust endotoxin, but its validity as a proxy for airborne exposure is unknown, while active airborne dust sampling is not feasible in large-scale population studies because of logistic and financial limitations. We therefore developed and evaluated a simple passive airborne dust collection method for airborne endotoxin exposure assessment. We explored an electrostatic dust fall collector (EDC), consisting of a 42- by 29.6-cm-sized folder with four electrostatic cloths exposed to the air. The EDC was tested during two 14-day periods in seven nonfarm and nine farm homes and in farm stables. In parallel, active airborne dust sampling was performed with Harvard impactors and floor dust collected by vacuuming, using nylon sampling socks. The endotoxin levels could be measured in all EDC cloth extracts. The levels (in EU/m(2)) between EDCs used simultaneously or in different sampling periods in the same home correlated strongly (r > 0.8). EDC endotoxin also correlated moderately to strongly (r = 0.6 to 0.8) with the endotoxin measured by active airborne dust sampling and living room floor dust sampling and-in farm homes-with the endotoxin captured by the EDC in stables. In contrast, endotoxin levels measured by floor dust sampling showed only a poor correlation with the levels measured by active airborne dust sampling. We therefore conclude that measuring endotoxin levels with the EDC is a valid measure of average airborne endotoxin exposure, while reproducibility over time is at least equivalent to that of reservoir dust analyses.

  15. Personal endotoxin exposure in a panel study of school children with asthma

    PubMed Central

    2011-01-01

    Background Endotoxin exposure has been associated with asthma exacerbations and increased asthma prevalence. However, there is little data regarding personal exposure to endotoxin in children at risk, or the relation of personal endotoxin exposure to residential or ambient airborne endotoxin. The relation between personal endotoxin and personal air pollution exposures is also unknown. Methods We characterized personal endotoxin exposures in 45 school children with asthma ages 9-18 years using 376 repeated measurements from a PM2.5 active personal exposure monitor. We also assayed endotoxin in PM2.5 samples collected from ambient regional sites (N = 97 days) and from a subset of 12 indoor and outdoor subject home sites (N = 109 and 111 days, respectively) in Riverside and Whittier, California. Endotoxin was measured using the Limulus Amoebocyte Lysate kinetic chromogenic assay. At the same time, we measured personal, home and ambient exposure to PM2.5 mass, elemental carbon (EC), and organic carbon (OC). To assess exposure relations we used both rank correlations and mixed linear regression models, adjusted for personal temperature and relative humidity. Results We found small positive correlations of personal endotoxin with personal PM2.5 EC and OC, but not personal PM2.5 mass or stationary site air pollutant measurements. Outdoor home, indoor home and ambient endotoxin were moderately to strongly correlated with each other. However, in mixed models, personal endotoxin was not associated with indoor home or outdoor home endotoxin, but was associated with ambient endotoxin. Dog and cat ownership were significantly associated with increased personal but not indoor endotoxin. Conclusions Daily fixed site measurements of endotoxin in the home environment may not predict daily personal exposure, although a larger sample size may be needed to assess this. This conclusion is relevant to short-term exposures involved in the acute exacerbation of asthma. PMID:21810249

  16. Coarse particulate matter and airborne endotoxin within wood stove homes.

    PubMed

    McNamara, M; Thornburg, J; Semmens, E; Ward, T; Noonan, C

    2013-12-01

    Emissions from indoor biomass burning are a major public health concern in developing areas of the world. Less is known about indoor air quality, particularly airborne endotoxin, in homes burning biomass fuel in residential wood stoves in higher income countries. A filter-based sampler was used to evaluate wintertime indoor coarse particulate matter (PM₁₀₋₂.₅) and airborne endotoxin (EU/m³, EU/mg) concentrations in 50 homes using wood stoves as their primary source of heat in western Montana. We investigated number of residents, number of pets, dampness (humidity), and frequency of wood stove usage as potential predictors of indoor airborne endotoxin concentrations. Two 48-h sampling events per home revealed a mean winter PM₁₀₋₂.₅ concentration (± s.d.) of 12.9 (± 8.6) μg/m³, while PM₂.₅ concentrations averaged 32.3 (± 32.6) μg/m³. Endotoxin concentrations measured from PM₁₀₋₂.₅ filter samples were 9.2 (± 12.4) EU/m³ and 1010 (± 1524) EU/mg. PM₁₀₋₂.₅ and PM₂.₅ were significantly correlated in wood stove homes (r = 0.36, P < 0.05). The presence of pets in the homes was associated with PM₁₀₋₂.₅ but not with endotoxin concentrations. Importantly, none of the other measured home characteristics was a strong predictor of airborne endotoxin, including frequency of residential wood stove usage.

  17. School Endotoxin Exposure and Asthma Morbidity in Inner-city Children

    PubMed Central

    Lai, Peggy S.; Sheehan, William J.; Gaffin, Jonathan M.; Petty, Carter R.; Coull, Brent A.; Gold, Diane R.; Phipatanakul, Wanda

    2015-01-01

    BACKGROUND: Endotoxin exposure is associated with airway inflammation. Children spend 6 to 8 h/d in school, yet the effect of school-specific endotoxin exposure on asthma morbidity is not well understood. METHODS: In this longitudinal cohort study, 248 students with asthma, from 38 inner-city schools, underwent baseline phenotyping and follow-up. Clinical outcomes were evaluated throughout the academic school year and linked to classroom-specific dust and air endotoxin levels as well as home dust endotoxin levels. The primary outcome was maximum asthma symptom-days per 2-week period. RESULTS: Classrooms had higher settled dust endotoxin levels compared with homes (14.3 endotoxin unit/mg vs 11.3 endotoxin unit/mg; P = .02). Airborne endotoxin levels exceeding recommended occupational exposure limits for adults were recorded in 22.0% of classrooms. Classroom air endotoxin levels were independently associated with increased maximum symptom-days in children with nonatopic asthma, but not in those with atopic asthma (interaction P = .03). Adjusting for home exposures, classroom endotoxin exposure was independently associated with a dose-dependent increase in asthma symptom-days for children with nonatopic asthma (adjusted incidence rate ratio, 1.16 [95% CI, 1.03-1.31]; P = .02). In these subjects, maximum symptom-days increased by 1.3 days for each 14-day period when comparing students in classrooms with the lowest endotoxin levels compared with average measured levels. CONCLUSIONS: Inner-city children with asthma are exposed to high levels of airborne endotoxin at school, resulting in increased asthma symptoms in children with nonatopic asthma. Mitigation of school-related exposures may represent a strategy to decrease asthma morbidity in this population. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01756391; URL: www.clinicaltrials.gov PMID:26087201

  18. Characterization of an aerosol chamber for human exposures to endotoxin.

    PubMed

    Taylor, L; Reist, P C; Boehlecke, B A; Jacobs, R R

    2000-03-01

    The objective of this study was to develop and characterize an exposure chamber in which human subjects could be exposed to low dust concentrations carrying an endotoxin coating. An exposure chamber, dust dispersion method, and endotoxin characterization technique were developed for inhalation exposures. A 6.27 m3 exposure chamber was designed and constructed from cinder block, glass windows, and Plexiglas. Using an acetone adhesion process, Enterobacter agglomerans were adsorbed onto respirable cellulose particles to create the endotoxin aerosol. The size distribution of the endotoxin-treated particles was verified using light microscopy and cascade impactors. A dry powder dust generator was refined to consistently disperse small quantities of the aerosol into the chamber to maintain dust concentrations at approximately 250 micrograms/m3. Dust levels during the chamber exposures were monitored using a portable continuous aerosol monitor (PCAM). During initial exposure runs, PCAM monitoring stations were positioned at different locations within a 0.5-meter matrix to document mixing patterns. Total dust and cascade impactor samples were collected throughout each exposure period to characterize the chamber operating system and insure the mean airborne dust concentration fulfilled target levels. A one-factor analysis of variance at the 95 percent confidence interval illustrated that there was not a statistically significant difference in the mean dust concentration throughout the exposure runs compared to the individual runs. Together the consistency of the total dust filters, endotoxin concentrations, and aerosol-monitoring instrument were adequate to allow use of the chamber for experimental studies involving human volunteers.

  19. Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China.

    PubMed Central

    Olenchock, S A; Christiani, D C; Mull, J C; Ye, T T; Lu, P L

    1983-01-01

    Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels. PMID:6639029

  20. A brief report of gram-negative bacterial endotoxin levels in airborne and settled dusts in animal confinement buildings

    SciTech Connect

    Thedell, T.D.; Mull, J.C.; Olenchock, S.A.

    1980-01-01

    Gram-negative bacterial endotoxins, implicated in adverse worker health responses, were found in settled and airborne dust samples obtained from poultry and swine confinement units. Results of the Limulus amebocyte lysate gel test found endotoxin levels in dust samples ranged from 4.5 to 47.7 micrograms of FDA Klebsiella endotoxin equivalents/gm. Differences in endotoxin levels between dust samples may have been due to variables in time, geographic locations, confined animals, confinement buildings and equipment, and methods of sample collection. Animal confinement workers are potentially exposed to large amounts of gram-negative bacterial endotoxins; however, the respiratory health effects of such exposures to animal confinement workers have yet to be determined.

  1. Airborne Endotoxin from Indoor and Outdoor Environments:Effect of Sample Dilution on the Kinetic Limulus Amebocyte Lysate (LAL) Assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne endotoxin in occupational environments are a potential respiratory hazard to individuals. In this study, total and inhalable airborne endotoxin samples were collected via filtration from inside animal housing units and downwind from agricultural production sites and a wastewater treatment ...

  2. Passive airborne dust sampling with the electrostatic dustfall collector: optimization of storage and extraction procedures for endotoxin and glucan measurement.

    PubMed

    Noss, Ilka; Doekes, Gert; Sander, Ingrid; Heederik, Dick J J; Thorne, Peter S; Wouters, Inge M

    2010-08-01

    We recently introduced a passive dust sampling method for airborne endotoxin and glucan exposure assessment-the electrostatic dustfall collector (EDC). In this study, we assessed the effects of different storage and extraction procedures on measured endotoxin and glucan levels, using 12 parallel EDC samples from 10 low exposed indoor environments. Additionally, we compared 2- and 4-week sampling with the prospect of reaching higher dust yields. Endotoxin concentrations were highest after extraction with pyrogen-free water (pf water) + Tween. Phosphate-buffered saline (PBS)-Tween yielded significantly (44%) lower levels, and practically no endotoxin was detected after extraction in pf water without Tween. Glucan levels were highest after extraction in PBS-Tween at 120 degrees C, whereas extracts made in NaOH at room temperature or 120 degrees C were completely negative. Direct extraction from the EDC cloth or sequential extraction after a preceding endotoxin extraction yielded comparable glucan levels. Sample storage at different temperatures before extraction did not affect endotoxin and glucan concentrations. Doubling the sampling duration yielded similar endotoxin and only 50% higher glucan levels. In conclusion, of the tested variables, the extraction medium was the predominant factor affecting endotoxin and glucan yields.

  3. Airborne endotoxin and its relationship to pulmonary function among workers in an Indian jute mill.

    PubMed

    Mukherjee, Ashit K; Chattopadhyay, Bhakar P; Bhattacharya, Sanat K; Saiyed, Habibullah N

    2004-04-01

    Air samples from various processing areas of an Indian jute mill were examined for endotoxin. The authors assessed work-related respiratory symptoms and pulmonary function changes in the dust-exposed workers from the different processing areas using a standard questionnaire and spirometry. Endotoxin was estimated in water extract of jute dust from 3 milling areas, and in outside air, by the Limulus amebocyte lysate gel clot technique. The batching, spinning, and weaving areas of the jute mill showed endotoxin levels of 0.22-4.42 microg/m3, 0.04-1.47 microg/m3, and 0.01-0.07 microg/m3, respectively, values similar to those found in Indian cotton mills. Respiratory morbidities among the workers included typical byssinotic symptoms, along with acute changes in postshift forced expiratory volume in 1 s (FEV1.0) (31.8%). Results of this study demonstrated that increased exposure to bacterial endotoxin in airborne dust is related to byssinotic symptoms among Indian jute mill workers. Findings were similar to those reported previously for workers in the cotton, flax, and hemp industries.

  4. The effects of cage design on airborne allergens and endotoxin in animal rooms: high-volume measurements with an ion-charging device.

    PubMed

    Platts-Mills, James; Custis, Natalie; Kenney, Alice; Tsay, Amy; Chapman, Martin; Feldman, Sanford; Platts-Mills, Thomas

    2005-03-01

    Respiratory symptoms related to both endotoxins and animal allergens continue to be an important cause of occupational disease for animal technicians and scientists working with rodents. Better sampling methods for airborne allergens and endotoxin are needed to help standardize compliance with federal occupational health regulations. Using an ion-charging device, we sampled 20 mouse rooms and four rat rooms at the University of Virginia, along with 43 domestic living rooms in houses in the Charlottesville area with at least one cat or dog. The use of filter tops on cages corresponds to a 50-fold reduction in mean levels of both airborne allergens (P < 0.001) and endotoxin (P < 0.001). The use of vented cages with filtered exhaust ports was associated with additional reductions. However, the mean airborne endotoxin level in all rooms using filter tops without a filtered exhaust port on the cages was significantly lower (P = 0.003) than the level in domestic living rooms. Our results for maximum airborne allergens or endotoxin are comparable with previous reports. However, the sensitivity of the technique allows an accurate assessment of low-level exposure, which makes it possible to evaluate the effect of cage designs. In addition, this approach allows direct comparison with results for airborne allergen and endotoxin in domestic homes. The results could allow a more consistent approach to the application of occupational health guidelines. PMID:15773770

  5. [Exposure to endotoxins in the environment. Occurrence and health hazards].

    PubMed

    Rix, B A

    1997-04-21

    Endotoxins are lipopolysaccharides from the outer cell wall of Gram-negative bacteria. Exposure to endotoxins can take place in industries where organic material is handled, in agriculture, in garbage handling, and sewage treatment. Byssinosis defined as Monday chest tightness and slight dyspnoea in the work place has been related to endotoxin exposure in cotton mills, but studies indicate that similar symptoms may be found in other work places. Other symptoms are: Headache, nausea, gastrointestinal symptoms and influenza-like symptoms. Several studies have shown a decrease in FEV1 following exposure to endotoxins. The relationship between exposure to organic dust, microorganisms, endotoxins and other chemicals in the work place and disease needs further research.

  6. Endotoxin levels in settled airborne dust in European schools: the HITEA school study.

    PubMed

    Jacobs, J H; Krop, E J M; Borras-Santos, A; Zock, J-P; Taubel, M; Hyvarinnen, A; Pekkanen, J; Doekes, G; Heederik, D J J

    2014-04-01

    Indoor exposure to microbial agents is known to influence respiratory health. Besides home exposure, exposure in schools can affect respiratory health. In this study, we measured endotoxin in settled dust in primary schools in three European countries from three different geographical regions with different climates. Our aim was to characterize endotoxin levels in primary schools and evaluate associations with potential determinants. Endotoxin levels were repeatedly assessed in 23 schools in Spain (n = 7), the Netherlands (n = 10), and Finland (n = 6) using electrostatic dustfall collectors. In total, 645 measurements were taken in 237 classrooms. Endotoxin levels differed significantly between countries; Dutch schools had the highest levels, while Finnish schools showed the lowest levels. In each country, differences in endotoxin levels were observed between schools and over the sampling periods. Estimates improved after adjustment for sampling period. Factors affecting endotoxin levels in a school differed per country. In general, endotoxin levels were higher in lower grades and in classrooms with higher occupancy. School endotoxin levels may contribute significantly to total endotoxin exposure in children and teachers. As the correlation between the repeated measurements is reasonable, single endotoxin measurements form a reasonable basis for estimating annual endotoxin levels in schools.

  7. Effect of deployment time on endotoxin and allergen exposure assessment using electrostatic dust collectors.

    PubMed

    Kilburg-Basnyat, Brita; Metwali, Nervana; Thorne, Peter S

    2015-01-01

    The electrostatic dust collector (EDC) is a passive dust sampling device for exposure assessment of airborne endotoxin and possibly allergens. EDCs consist of a non-conducting plastic folder holding two or four electrostatic cloths of defined area. The sampling time needed to achieve detectable and reproducible loading for bioaerosols has not been systematically evaluated. Thus, in 15 Iowa farm homes EDCs were deployed for 7-, 14-, and 28-day sampling periods to determine if endotoxin and allergens could be quantified and if loading rates were uniform over time, i.e. if loads doubled from 7 to 14 days or 14 to 28 days and quadrupled from 7 to 28 days. Loadings between left and right paired EDC cloths were not significantly different and were highly correlated for endotoxin, total protein, and cat (Fel d1), dog (Can f1), and mouse (Mus m1) allergens (P < 0.001). EDCs performed especially well for endotoxin sampling with close agreement between paired samples (Pearson r = 0.96, P < 0.001). Endotoxin loading of the EDCs doubled from 7- to 14-day deployments as hypothesized although the loading rate decreased from 14 to 28 days of sampling with only a 1.38-fold increase. Allergen exposure assessment using EDCs was overall less satisfactory. Although there was reasonable agreement between paired samples, only exposures to cat, dog, and mouse allergens were reliable and these only at the longer deployment times.

  8. Effect of Deployment Time on Endotoxin and Allergen Exposure Assessment Using Electrostatic Dust Collectors

    PubMed Central

    Kilburg-Basnyat, Brita; Metwali, Nervana; Thorne, Peter S.

    2015-01-01

    The electrostatic dust collector (EDC) is a passive dust sampling device for exposure assessment of airborne endotoxin and possibly allergens. EDCs consist of a non-conducting plastic folder holding two or four electrostatic cloths of defined area. The sampling time needed to achieve detectable and reproducible loading for bioaerosols has not been systematically evaluated. Thus, in 15 Iowa farm homes EDCs were deployed for 7-, 14-, and 28-day sampling periods to determine if endotoxin and allergens could be quantified and if loading rates were uniform over time, i.e. if loads doubled from 7 to 14 days or 14 to 28 days and quadrupled from 7 to 28 days. Loadings between left and right paired EDC cloths were not significantly different and were highly correlated for endotoxin, total protein, and cat (Fel d1), dog (Can f1), and mouse (Mus m1) allergens (P < 0.001). EDCs performed especially well for endotoxin sampling with close agreement between paired samples (Pearson r = 0.96, P < 0.001). Endotoxin loading of the EDCs doubled from 7- to 14-day deployments as hypothesized although the loading rate decreased from 14 to 28 days of sampling with only a 1.38-fold increase. Allergen exposure assessment using EDCs was overall less satisfactory. Although there was reasonable agreement between paired samples, only exposures to cat, dog, and mouse allergens were reliable and these only at the longer deployment times. PMID:25187036

  9. The effect of extraction, storage, and analysis techniques on the measurement of airborne endotoxin from a large dairy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to fill in additional knowledge gaps with respect to the extraction, storage, and analysis of airborne endotoxin, with a specific focus on samples from a dairy production facility. We utilized polycarbonate filters to collect total airborne endotoxins, sonication as ...

  10. Airborne environmental endotoxin: a cross-validation of sampling and analysis techniques.

    PubMed Central

    Walters, M; Milton, D; Larsson, L; Ford, T

    1994-01-01

    A standard method for measurement of airborne environmental endotoxin was developed and field tested in a fiberglass insulation-manufacturing facility. This method involved sampling with a capillary-pore membrane filter, extraction in buffer using a sonication bath, and analysis by the kinetic-Limulus assay with resistant-parallel-line estimation (KLARE). Cross-validation of the extraction and assay method was performed by comparison with methanolysis of samples followed by 3-hydroxy fatty acid (3-OHFA) analysis by gas chromatography-mass spectrometry. Direct methanolysis of filter samples and methanolysis of buffer extracts of the filters yielded similar 3-OHFA content (P = 0.72); the average difference was 2.1%. Analysis of buffer extracts for endotoxin content by the KLARE method and by gas chromatography-mass spectrometry for 3-OHFA content produced similar results (P = 0.23); the average difference was 0.88%. The source of endotoxin was gram-negative bacteria growing in recycled washwater used to clean the insulation-manufacturing equipment. The endotoxin and bacteria become airborne during spray cleaning operations. The types of 3-OHFAs in bacteria cultured from the washwater, present in the washwater and in the air, were similar. Virtually all of the bacteria cultured from air and water were gram negative composed mostly of two species, Deleya aesta and Acinetobacter johnsonii. Airborne countable bacteria correlated well with endotoxin (r2 = 0.64). Replicate sampling showed that results with the standard sampling, extraction, and Limulus assay by the KLARE method were highly reproducible (95% confidence interval for endotoxin measurement +/- 0.28 log10). These results demonstrate the accuracy, precision, and sensitivity of the standard procedure proposed for airborne environmental endotoxin. PMID:8161191

  11. Workplace Determinants of Endotoxin Exposure in Dental Healthcare Facilities in South Africa

    PubMed Central

    Singh, Tanusha S.; Bello, Braimoh; Mabe, Onnicah D.; Renton, Kevin; Jeebhay, Mohamed F.

    2010-01-01

    Objectives: Aerosols generated during dental procedures have been reported to contain endotoxin as a result of bacterial contamination of dental unit water lines. This study investigated the determinants of airborne endotoxin exposure in dental healthcare settings. Methods: The study population included dental personnel (n = 454) from five academic dental institutions in South Africa. Personal air samples (n = 413) in various dental jobs and water samples (n = 403) from dental handpieces and basin taps were collected. The chromogenic-1000 limulus amebocyte lysate assay was used to determine endotoxin levels. Exposure metrics were developed on the basis of individually measured exposures and average levels within each job category. Analysis of variance and multivariate linear regression models were constructed to ascertain the determinants of exposure in the dental group. Results: There was a 2-fold variation in personal airborne endotoxin from the least exposed (administration) to the most exposed (laboratory) jobs (geometric mean levels: 2.38 versus 5.63 EU m−3). Three percent of personal samples were above DECOS recommended exposure limit (50 EU m−3). In the univariate linear models, the age of the dental units explained the most variability observed in the personal air samples (R2 = 0.20, P < 0.001), followed by the season of the year (R2 = 0.11, P < 0.001). Other variables such as institution and total number of dental units per institution also explained a modest degree of variability. A multivariate model explaining the greatest variability (adjusted R2 = 0.40, P < 0.001) included: the age of institution buildings, total number of dental units per institution, ambient temperature, ambient air velocity, endotoxin levels in water, job category (staff versus students), dental unit model type and age of dental unit. Conclusions: Apart from job type, dental unit characteristics are important predictors of airborne endotoxin

  12. Evaluation Of Airborne Endotoxin Concentrations Associated With Management Of Crop Grown On Applied Biosolids

    EPA Science Inventory

    Public health concerns have been expressed regarding inhalation exposure associated with the application of biosolids on cropland, which is due to the potential aerosolization of microorganisms, cell wall products, volatile chemicals, and nuisance odors. Endotoxin is a component...

  13. Hormone and Cytokine Responses to Repeated Endotoxin Exposures-No Evidence of Endotoxin Tolerance After 5 Weeks in Humans.

    PubMed

    Rittig, Nikolaj; Thomsen, Henrik H; Bach, Ermina; Jørgensen, Jens Otto L; Møller, Niels

    2015-07-01

    Endotoxin administrations are used in experimental models of inflammatory disease. Short-term endotoxin tolerance in response to repeated endotoxin exposure is well known, but the duration of endotoxin tolerance in humans remains unknown. The main purpose of this study was to test whether endotoxin tolerance is present in vivo when separating endotoxin exposures with more than 5 weeks, a time span often used between individual investigations in clinical experimental studies. Seventeen healthy young men were exposed twice to Escherichia coli endotoxin. The inflammatory response was calculated as area under the curve between the first and second endotoxin exposures for heart rate, mean arterial blood pressure, temperature, cortisol, tumor necrosis factor α, and interleukin (IL)-1β, IL-6, and IL-10. The median interval between exposures was 90 days (range, 37-244). The ratio between the inflammatory responses during the second and the first endotoxin exposures was 0.89 ± 0.09 (P = 0.28) for tumor necrosis factor α, 0.96 ± 0.07 (P = 0.53) for IL-1β, 0.97 ± 0.11 (P = 0.78) for IL-6, 1.30 ± 0.18 (P = 0.12) for IL-10, and 0.92 ± 0.04 (P = 0.10) for cortisol. Our data do not show evidence of in vivo tolerance to repeated endotoxin exposure when administrations are separated with at least 5 weeks. This observation is important in the planning and interpretation of future experimental endotoxin studies.

  14. Endotoxin Exposure and Eczema in the First Year of Life

    PubMed Central

    Phipatanakul, Wanda; Celedón, Juan C.; Raby, Benjamin A.; Litonjua, Augusto A.; Milton, Donald K.; Sredl, Diane; Weiss, Scott T.; Gold, Diane R.

    2005-01-01

    Objective Exposure to endotoxin in early life has been proposed as a factor that may protect against the development of allergic diseases such as eczema. The objective of this study was to examine the relation between endotoxin exposure in early life and eczema in the first year of life in children with parental history of asthma or allergies. Methods This study used a prospective birth cohort study of 498 children who had a history of allergy or asthma in at least 1 parent and lived in metropolitan Boston. A subset of 401 living rooms had house dust samples adequate for analysis of endotoxin. Results In multivariate analyses adjusting for gender, income, and season of birth, endotoxin levels in the living room at 2 to 3 months of age was inversely associated with physician- or nurse-diagnosed eczema in the first year of life (odds ratio [OR] for each quartile increment: 0.76; 95% confidence interval [CI]: 0.61–0.96). Exposure to a dog in the home at age 2 to 3 months was also inversely associated with eczema in the first year of life, but the CI widened when endotoxin was included in the multivariate model (OR: 0.54; 95% CI: 0.27–1.09). Other variables associated with eczema in the first year of life included paternal history of eczema (OR: 1.91; 95% CI: 1.03–3.55) and maternal specific immunoglobulin E positivity to ≥1 allergen (OR: 1.61; 95% CI: 1.01–2.56). Conclusions Among children with parental history of asthma or allergies, exposure to high levels of endotoxin in early life may be protective against eczema in the first year of life. In these children, paternal history of eczema and maternal sensitization to at least 1 allergen are associated with an increased risk of eczema in the first year of life. PMID:15231902

  15. Characterization of Airborne Molds, Endotoxins, and Glucans in Homes in New Orleans after Hurricanes Katrina and Rita▿

    PubMed Central

    Rao, Carol Y.; Riggs, Margaret A.; Chew, Ginger L.; Muilenberg, Michael L.; Thorne, Peter S.; Van Sickle, David; Dunn, Kevin H.; Brown, Clive

    2007-01-01

    In August and September 2005, Hurricanes Katrina and Rita caused breeches in the New Orleans, LA, levee system, resulting in catastrophic flooding. The city remained flooded for several weeks, leading to extraordinary mold growth in homes. To characterize the potential risks of mold exposures, we measured airborne molds and markers of molds and bacteria in New Orleans area homes. In October 2005, we collected air samples from 5 mildly water-damaged houses, 15 moderately to heavily water-damaged houses, and 11 outdoor locations. The air filters were analyzed for culturable fungi, spores, (1→3,1→6)-β-d-glucans, and endotoxins. Culturable fungi were significantly higher in the moderately/heavily water-damaged houses (geometric mean = 67,000 CFU/m3) than in the mildly water-damaged houses (geometric mean = 3,700 CFU/m3) (P = 0.02). The predominant molds found were Aspergillus niger, Penicillium spp., Trichoderma, and Paecilomyces. The indoor and outdoor geometric means for endotoxins were 22.3 endotoxin units (EU)/m3 and 10.5 EU/m3, respectively, and for (1→3,1→6)-β-d-glucans were 1.7 μg/m3 and 0.9 μg/m3, respectively. In the moderately/heavily water-damaged houses, the geometric means were 31.3 EU/m3 for endotoxins and 1.8 μg/m3 for (1→3,1→6)-β-d-glucans. Molds, endotoxins, and fungal glucans were detected in the environment after Hurricanes Katrina and Rita in New Orleans at concentrations that have been associated with health effects. The species and concentrations were different from those previously reported for non-water-damaged buildings in the southeastern United States. PMID:17209066

  16. Characterization of airborne molds, endotoxins, and glucans in homes in New Orleans after Hurricanes Katrina and Rita.

    PubMed

    Rao, Carol Y; Riggs, Margaret A; Chew, Ginger L; Muilenberg, Michael L; Thorne, Peter S; Van Sickle, David; Dunn, Kevin H; Brown, Clive

    2007-03-01

    In August and September 2005, Hurricanes Katrina and Rita caused breeches in the New Orleans, LA, levee system, resulting in catastrophic flooding. The city remained flooded for several weeks, leading to extraordinary mold growth in homes. To characterize the potential risks of mold exposures, we measured airborne molds and markers of molds and bacteria in New Orleans area homes. In October 2005, we collected air samples from 5 mildly water-damaged houses, 15 moderately to heavily water-damaged houses, and 11 outdoor locations. The air filters were analyzed for culturable fungi, spores, (1-->3,1-->6)-beta-D-glucans, and endotoxins. Culturable fungi were significantly higher in the moderately/heavily water-damaged houses (geometric mean=67,000 CFU/m3) than in the mildly water-damaged houses (geometric mean=3,700 CFU/m3) (P=0.02). The predominant molds found were Aspergillus niger, Penicillium spp., Trichoderma, and Paecilomyces. The indoor and outdoor geometric means for endotoxins were 22.3 endotoxin units (EU)/m3 and 10.5 EU/m3, respectively, and for (1-->3,1-->6)-beta-D-glucans were 1.7 microg/m3 and 0.9 microg/m3, respectively. In the moderately/heavily water-damaged houses, the geometric means were 31.3 EU/m3 for endotoxins and 1.8 microg/m3 for (1-->3,1-->6)-beta-D-glucans. Molds, endotoxins, and fungal glucans were detected in the environment after Hurricanes Katrina and Rita in New Orleans at concentrations that have been associated with health effects. The species and concentrations were different from those previously reported for non-water-damaged buildings in the southeastern United States.

  17. Regulation of TB vaccine-induced airway luminal T cells by respiratory exposure to endotoxin.

    PubMed

    Chen, Xuerong; Xiu, Fangming; Horvath, Carly N; Damjanovic, Daniela; Thanthrige-Don, Niroshan; Jeyanathan, Mangalakumari; Xing, Zhou

    2012-01-01

    Tuberculosis (TB) vaccine-induced airway luminal T cells (ALT) have recently been shown to be critical to host defense against pulmonary TB. However, the mechanisms that maintain memory ALT remain poorly understood. In particular, whether respiratory mucosal exposure to environmental agents such as endotoxin may regulate the size of vaccine-induced ALT population is still unclear. Using a murine model of respiratory genetic TB vaccination and respiratory LPS exposure, we have addressed this issue in the current study. We have found that single or repeated LPS exposure increases the number of antigen-specific ALT which are capable of robust secondary responses to pulmonary mycobacterial challenge. To investigate the potential mechanisms by which LPS exposure modulates the ALT population, we have examined the role of ALT proliferation and peripheral T cell recruitment. We have found that LPS exposure-increased ALT is not dependent on increased ALT proliferation as respiratory LPS exposure does not significantly increase the rate of proliferation of ALT. But rather, we find it to be dependent upon the recruitment of peripheral T cells into the airway lumen as blockade of peripheral T cell supplies markedly reduces the initially increased ALT. Thus, our data suggest that environmental exposure to airborne agents such as endotoxin has a profound modulatory effect on TB vaccine-elicited T cells within the respiratory tract. Our study provides a new, M.tb antigen-independent mechanism by which the respiratory mucosal anti-TB memory T cells may be maintained.

  18. Seasonal variation in airborne endotoxin levels in indoor environments with different micro-environmental factors in Seoul, South Korea.

    PubMed

    Hwang, Sung Ho; Park, Dong Jin; Park, Wha Me; Park, Dong Uk; Ahn, Jae Kyoung; Yoon, Chung Sik

    2016-02-01

    This study evaluated the variation over a year in airborne endotoxin levels in the indoor environment of five university laboratories in Seoul, South Korea, and examined the micro-environmental factors that influenced endotoxin levels. These included temperature, relative humidity, CO2, CO, illumination, and wind velocity. A total of 174 air samples were collected and analyzed using the kinetic limulus amebocyte lysate assay. Endotoxin levels ranged from <0.001 to 8.90EU/m(3), with an overall geometric mean of 0.240EU/m(3). Endotoxin levels showed significantly negative correlation with temperature (r=-0.529, p<0.001), CO2 (r=-0.213, p<0.001) and illumination (r=-0.538, p<0.001). Endotoxin levels tended to be higher in winter. Endotoxin levels in laboratories with rabbits were significantly higher than those of laboratories with mice. Multivariate regression analysis showed that the environmental factors affecting endotoxin levels were temperature (coefficient=-0.388, p<0.001) and illumination (coefficient=-0.370, p<0.001). Strategies aimed at reducing airborne endotoxin levels in the indoor environments may be most effective if they focus on illumination. PMID:26656510

  19. Seasonal variation in airborne endotoxin levels in indoor environments with different micro-environmental factors in Seoul, South Korea.

    PubMed

    Hwang, Sung Ho; Park, Dong Jin; Park, Wha Me; Park, Dong Uk; Ahn, Jae Kyoung; Yoon, Chung Sik

    2016-02-01

    This study evaluated the variation over a year in airborne endotoxin levels in the indoor environment of five university laboratories in Seoul, South Korea, and examined the micro-environmental factors that influenced endotoxin levels. These included temperature, relative humidity, CO2, CO, illumination, and wind velocity. A total of 174 air samples were collected and analyzed using the kinetic limulus amebocyte lysate assay. Endotoxin levels ranged from <0.001 to 8.90EU/m(3), with an overall geometric mean of 0.240EU/m(3). Endotoxin levels showed significantly negative correlation with temperature (r=-0.529, p<0.001), CO2 (r=-0.213, p<0.001) and illumination (r=-0.538, p<0.001). Endotoxin levels tended to be higher in winter. Endotoxin levels in laboratories with rabbits were significantly higher than those of laboratories with mice. Multivariate regression analysis showed that the environmental factors affecting endotoxin levels were temperature (coefficient=-0.388, p<0.001) and illumination (coefficient=-0.370, p<0.001). Strategies aimed at reducing airborne endotoxin levels in the indoor environments may be most effective if they focus on illumination.

  20. SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH

    EPA Science Inventory

    Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (<_ 1....

  1. Residential indoor and outdoor coarse particles and associated endotoxin exposures

    NASA Astrophysics Data System (ADS)

    Wheeler, Amanda J.; Dobbin, Nina A.; Lyrette, Ninon; Wallace, Lance; Foto, Mark; Mallick, Ranjeeta; Kearney, Jill; Van Ryswyk, Keith; Gilbert, Nicolas L.; Harrison, Ian; Rispler, Kathleen; Héroux, Marie-Eve

    2011-12-01

    There is a growing body of evidence demonstrating that coarse particles (PM 10-2.5) have detrimental impacts upon health, especially for respiratory effects. There are limited data available for indoor residential exposures. Some data exist regarding the composition of this PM size fraction with emphasis on crustal elements and biological components. This study includes data from 146 homes sampled in Regina, Saskatchewan (SK) where 5-day integrated concurrent monitoring of indoor and outdoor coarse particles was conducted during the winter and summer of 2007. The coarse particle filters were subsequently analysed for endotoxin content to determine the contribution of this compound. Winter indoor geometric mean concentrations of coarse particles exceeded outdoor concentrations (3.73 μg m -3 vs 2.49 μg m -3; paired t-test p < 0.0001); however the reverse was found in summer (4.34 μg m -3 vs 8.82 μg m -3; paired t-test p < 0.0001). Linear regression indicated that winter predictors of indoor coarse particles were outdoor coarse particles, ventilation and presence of at least two or more occupants. During the summer, increased use of central air conditioning was associated with reduced coarse particles, while smoking and the presence of two or more occupants resulted in increased coarse particles. Endotoxin concentrations (EU μg -1) were lower indoors than outdoors in both seasons. Spatial variability of ambient coarse particles was assessed to determine the suitability of using a single monitoring station within a city to estimate exposure. The coefficients of variation between homes sampled simultaneously and the central monitoring station were calculated (median COV in summer = 15% and winter = 24%) and showed significant variability by week, especially during the summer months, suggesting a single site may be insufficient for characterizing exposure. Future studies should consider daily measurements per home to understand shorter term exposures and day to day

  2. Exposure to Dust and Endotoxin of Employees in Cucumber and Tomato Nurseries

    PubMed Central

    Madsen, A. M.; Hansen, V. M.; Nielsen, S. H.; Olsen, T. T.

    2009-01-01

    Exposure to bioaerosols in occupational settings is associated with a range of adverse health effects. The aim of this study was to investigate the exposure levels to dust and endotoxin of people working in two cucumber nurseries and two tomato nurseries. Exposure was measured for greenhouse workers (n = 70) mainly working on harvesting cucumbers and tomatoes and clearing the plants after the harvest season. The people were exposed to between 0.2 and 15 mg inhalable dust m−3 (median = 1.6 mg m−3) and between 0.5 and 400 ng inhalable endotoxin m−3 (median = 32 ng m−3). The exposure to ‘total dust’ and endotoxin measured by stationary samplers (n = 30) in the greenhouses was low. Endotoxin was present in relatively high concentrations on cucumber leaves compared with leaves on pot plants. The Danish occupational exposure limit (OEL) for total organic dust is 3 mg m−3 and 36% and 17% of the cucumber and tomato workers, respectively, were exposed to >3.0 mg inhalable dust m−3. There is no OEL for endotoxin, but ‘no effect levels’ at ∼15 ng m−3 have been found. The majority of subjects (65%) were exposed to >15 ng m−3. Significantly higher exposure was found for employees in cucumber nurseries than for employees in tomato nurseries. Clearing tomato plants after the harvest season caused a higher exposure to endotoxin than tomato harvesting. In conclusion, people working in cucumber and tomato nurseries were often exposed to high levels of inhalable dust and endotoxin. Cucumber harvest workers were exposed to significantly more dust and endotoxin than tomato harvest workers. The dust and endotoxin aerosolized during the working processes were only transported to other areas in the greenhouses to a very low degree. Cucumber and tomato leaves were identified as endotoxin reservoirs. PMID:19033558

  3. Assessment of Swine Worker Exposures to Dust and Endotoxin during Hog Load-Out and Power Washing

    PubMed Central

    O’shaughnessy, Patrick; Peters, Thomas; Donham, Kelley; Taylor, Craig; Altmaier, Ralph; Kelly, Kevin

    2012-01-01

    Field measurements of personal and area dust and endotoxin concentrations were obtained while agricultural workers performed two work tasks that have been previously unreported: hog load-out and swine building power washing. Hog load-out involves moving hogs from their pens in finishing buildings into a truck for transport to a meat processor. High pressure power washing is conducted for sanitation purposes after a building has been emptied of hogs to remove surface and floor debris. This debri consists of feed, feces, and hog dander as dust or an encrusted form. The hog load-out process necessarily increases pig activity which is known to increase airborne dust concentrations. An unintended consequence of power washing is that the material covering surfaces is forcibly ejected into the atmosphere, creating the potential for a highly concentrated aerosol exposure to workers. The load-out process resulted in a median personal inhalable mass concentration of 7.14 mg m− 3 and median endotoxin concentration of 12 150 endotoxin units (EU) m− 3. When converted to an 8-h time-weighted average for a ‘total’ sampler, one of the 19 samples exceeded a regulatory limit of 15 mg m− 3. An impinger was used to sample power washing endotoxin concentrations, which resulted in a median personal concentration of 40 350 EU m− 3. These concentrations were among the highest found in the literature for any occupation. With the lack of engineering controls present to reduce airborne contaminant concentrations in swine buildings, either respirator use or a reduction in exposure time is recommended while performing these tasks. PMID:22425653

  4. Short-term dynamics of indoor and outdoor endotoxin exposure: Case of Santiago, Chile, 2012.

    PubMed

    Barraza, Francisco; Jorquera, Héctor; Heyer, Johanna; Palma, Wilfredo; Edwards, Ana María; Muñoz, Marcelo; Valdivia, Gonzalo; Montoya, Lupita D

    2016-01-01

    Indoor and outdoor endotoxin in PM2.5 was measured for the very first time in Santiago, Chile, in spring 2012. Average endotoxin concentrations were 0.099 and 0.094 [EU/m(3)] for indoor (N=44) and outdoor (N=41) samples, respectively; the indoor-outdoor correlation (log-transformed concentrations) was low: R=-0.06, 95% CI: (-0.35 to 0.24), likely owing to outdoor spatial variability. A linear regression model explained 68% of variability in outdoor endotoxins, using as predictors elemental carbon (a proxy of traffic emissions), chlorine (a tracer of marine air masses reaching the city) and relative humidity (a modulator of surface emissions of dust, vegetation and garbage debris). In this study, for the first time a potential source contribution function (PSCF) was applied to outdoor endotoxin measurements. Wind trajectory analysis identified upwind agricultural sources as contributors to the short-term, outdoor endotoxin variability. Our results confirm an association between combustion particles from traffic and outdoor endotoxin concentrations. For indoor endotoxins, a predictive model was developed but it only explained 44% of endotoxin variability; the significant predictors were tracers of indoor PM2.5 dust (Si, Ca), number of external windows and number of hours with internal doors open. Results suggest that short-term indoor endotoxin variability may be driven by household dust/garbage production and handling. This would explain the modest predictive performance of published models that use answers to household surveys as predictors. One feasible alternative is to increase the sampling period so that household features would arise as significant predictors of long-term airborne endotoxin levels. PMID:27065310

  5. Short-term dynamics of indoor and outdoor endotoxin exposure: Case of Santiago, Chile, 2012.

    PubMed

    Barraza, Francisco; Jorquera, Héctor; Heyer, Johanna; Palma, Wilfredo; Edwards, Ana María; Muñoz, Marcelo; Valdivia, Gonzalo; Montoya, Lupita D

    2016-01-01

    Indoor and outdoor endotoxin in PM2.5 was measured for the very first time in Santiago, Chile, in spring 2012. Average endotoxin concentrations were 0.099 and 0.094 [EU/m(3)] for indoor (N=44) and outdoor (N=41) samples, respectively; the indoor-outdoor correlation (log-transformed concentrations) was low: R=-0.06, 95% CI: (-0.35 to 0.24), likely owing to outdoor spatial variability. A linear regression model explained 68% of variability in outdoor endotoxins, using as predictors elemental carbon (a proxy of traffic emissions), chlorine (a tracer of marine air masses reaching the city) and relative humidity (a modulator of surface emissions of dust, vegetation and garbage debris). In this study, for the first time a potential source contribution function (PSCF) was applied to outdoor endotoxin measurements. Wind trajectory analysis identified upwind agricultural sources as contributors to the short-term, outdoor endotoxin variability. Our results confirm an association between combustion particles from traffic and outdoor endotoxin concentrations. For indoor endotoxins, a predictive model was developed but it only explained 44% of endotoxin variability; the significant predictors were tracers of indoor PM2.5 dust (Si, Ca), number of external windows and number of hours with internal doors open. Results suggest that short-term indoor endotoxin variability may be driven by household dust/garbage production and handling. This would explain the modest predictive performance of published models that use answers to household surveys as predictors. One feasible alternative is to increase the sampling period so that household features would arise as significant predictors of long-term airborne endotoxin levels.

  6. Exposure matrices of endotoxin, (1→3)-β-d-glucan, fungi, and dust mite allergens in flood-affected homes of New Orleans.

    PubMed

    Adhikari, Atin; Lewis, Jocelyn Suzanne; Reponen, Tiina; Degrasse, Enjoli C; Grimsley, L Faye; Chew, Ginger L; Iossifova, Yulia; Grinshpun, Sergey A

    2010-10-15

    This study examined: (i) biocontaminant levels in flooded homes of New Orleans two years after the flooding; (ii) seasonal changes in biocontaminant levels, and (iii) correlations between biocontaminant levels obtained by different environmental monitoring methods. Endotoxin, (1→3)-β-d-glucan, fungal spores, and dust mite allergens were measured in 35 homes during summer and winter. A combination of dust sampling, aerosolization-based microbial source assessment, and long-term inhalable bioaerosol sampling aided in understanding exposure matrices. On average, endotoxin found in the aerosolized fraction accounted for <2% of that measured in the floor dust, suggesting that vacuuming could overestimate inhalation exposures. In contrast, the (1→3)-β-d-glucan levels in the floor dust and aerosolized fractions were mostly comparable, and 25% of the homes showed aerosolizable levels even higher than the dust-borne levels. The seasonal patterns for endotoxin in dust and the aerosolizable fraction were different from those found for (1→3)-β-d-glucan, reflecting the temperature and humidity effects on bacterial and fungal contamination. While the concentration of airborne endotoxin followed the same seasonal trend as endotoxin aerosolized from surfaces, no significant seasonal difference was identified for the concentrations of airborne (1→3)-β-d-glucan and fungal spores. This was attributed to the difference in the particle size; smaller endotoxin-containing particles can remain airborne for longer time than larger fungal spores or (1→3)-β-d-glucan-containing particles. It is also possible that fungal aerosolization in home environments did not reach its full potential. Detectable dust mite allergens were found only in dust samples, and more commonly in occupied homes. Levels of endotoxin, (1→3)-β-d-glucan, and fungi in air had decreased during the two-year period following the flooding as compared to immediate measurements; however, the dust

  7. Physical and biological properties of U. S. standard endotoxin EC after exposure to ionizing radiation

    SciTech Connect

    Csako, G.; Elin, R.J.; Hochstein, H.D.; Tsai, C.M.

    1983-07-01

    Techniques that reduce the toxicity of bacterial endotoxins are useful for studying the relationship between structure and biological activity. We used ionizing radiation to detoxify a highly refined endotoxin preparation. U.S. standard endotoxin EC. Dose-dependent changes occurred by exposure to /sup 60/Co-radiation in the physical properties and biological activities of the endotoxin. Sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis showed gradual loss of the polysaccharide components (O-side chain and R-core) from the endotoxin molecules. In contrast, although endotoxin revealed a complex absorption pattern in the UV range, radiation treatment failed to modify that pattern. Dose-related destruction of the primary toxic component, lipid A, was suggested by the results of activity tests: both the pyrogenicity and limulus reactivity of the endotoxin were destroyed by increasing doses of radiation. The results indicate that the detoxification is probably due to multiple effects of the ionizing radiation on bacterial lipopolysaccharides, and the action involves (i) the destruction of polysaccharide moieties and possibly (ii) the alteration of lipid A component of the endotoxin molecule.

  8. Human exposure to endotoxins and fecal indicators originating from water features.

    PubMed

    de Man, H; Heederik, D D J; Leenen, E J T M; de Roda Husman, A M; Spithoven, J J G; van Knapen, F

    2014-03-15

    Exposure to contaminated aerosols and water originating from water features may pose public health risks. Endotoxins in air and water and fecal bacteria in water of water features were measured as markers for exposure to microbial cell debris and enteric pathogens, respectively. Information was collected about wind direction, wind force, distance to the water feature, the height of the water feature and the tangibility of water spray. The mean concentration of endotoxins in air nearby and in water of 31 water features was 10 endotoxin units (EU)/m(3) (Geometric Mean (GM), range 0-85.5 EU/m(3) air) and 773 EU/mL (GM, range 9-18,170 EU/mL water), respectively. Such mean concentrations may be associated with respiratory health effects. The water quality of 26 of 88 water features was poor when compared to requirements for recreational water in the Bathing Water Directive 2006/7/EC. Concentrations greater than 1000 colony forming units (cfu) Escherichia coli per 100 mL and greater than 400 cfu intestinal enterococci per 100 mL increase the probability of acquiring gastrointestinal health complaints. Regression analyses showed that the endotoxin concentration in air was significantly influenced by the concentration of endotoxin in water, the distance to the water feature and the tangibility of water spray. Exposure to air and water near water features was shown to lead to exposure to endotoxins and fecal bacteria. The potential health risks resulting from such exposure to water features may be estimated by a quantitative microbial risk assessment (QMRA), however, such QMRA would require quantitative data on pathogen concentrations, exposure volumes and dose-response relationships. The present study provides estimates for aerosolisation ratios that can be used as input for QMRA to quantify exposure and to determine infection risks from exposure to water features. PMID:24231029

  9. Human exposure to endotoxins and fecal indicators originating from water features.

    PubMed

    de Man, H; Heederik, D D J; Leenen, E J T M; de Roda Husman, A M; Spithoven, J J G; van Knapen, F

    2014-03-15

    Exposure to contaminated aerosols and water originating from water features may pose public health risks. Endotoxins in air and water and fecal bacteria in water of water features were measured as markers for exposure to microbial cell debris and enteric pathogens, respectively. Information was collected about wind direction, wind force, distance to the water feature, the height of the water feature and the tangibility of water spray. The mean concentration of endotoxins in air nearby and in water of 31 water features was 10 endotoxin units (EU)/m(3) (Geometric Mean (GM), range 0-85.5 EU/m(3) air) and 773 EU/mL (GM, range 9-18,170 EU/mL water), respectively. Such mean concentrations may be associated with respiratory health effects. The water quality of 26 of 88 water features was poor when compared to requirements for recreational water in the Bathing Water Directive 2006/7/EC. Concentrations greater than 1000 colony forming units (cfu) Escherichia coli per 100 mL and greater than 400 cfu intestinal enterococci per 100 mL increase the probability of acquiring gastrointestinal health complaints. Regression analyses showed that the endotoxin concentration in air was significantly influenced by the concentration of endotoxin in water, the distance to the water feature and the tangibility of water spray. Exposure to air and water near water features was shown to lead to exposure to endotoxins and fecal bacteria. The potential health risks resulting from such exposure to water features may be estimated by a quantitative microbial risk assessment (QMRA), however, such QMRA would require quantitative data on pathogen concentrations, exposure volumes and dose-response relationships. The present study provides estimates for aerosolisation ratios that can be used as input for QMRA to quantify exposure and to determine infection risks from exposure to water features.

  10. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

    A method of estimation of inhalation exposure to airborne soil contaminants is presented. this method is derived from studies of airborne soil particles with radioactive tags. The concentration of contaminants in air (g/m{sup 3}) can be derived from the product of M, the suspended respirable dust mass concentration (g/m{sup 3}), S, the concentration of contaminant in the soil (g/g), and E{sub f}, an enhancement factor. Typical measurement methods and values of M, and E{sub f} are given along with highlights of experiences with this method.

  11. Endotoxin and gender modify lung function recovery after occupational organic dust exposure: a 30 year study

    PubMed Central

    Valeri, Linda; Zhang, Feng-ying; Zheng, Bu-Yong; Mehta, Amar J.; Shi, Jing; Su, Li; Brown, Dan; Eisen, Ellen A; Christiani, David C.

    2015-01-01

    OBJECTIVES The purpose of this study is to determine the trajectory of lung function change after exposure cessation to occupational organic dust exposure, and to identify factors that modify improvement. METHODS The Shanghai Textile Worker Study is a longitudinal study of 447 cotton workers exposed to endotoxin-containing dust and 472 silk workers exposed to non-endotoxin-containing dust. Spirometry was performed at 5 year intervals. Air sampling was performed to estimate individual cumulative exposures. The effect of work cessation on FEV1 was modeled using generalized additive mixed effects models to identify the trajectory of FEV1 recovery. Linear mixed effects models incorporating interaction terms were used to identify modifiers of FEV1 recovery. Loss to follow-up was accounted for with inverse probability of censoring weights. RESULTS 74.2% of the original cohort still alive participated in 2011. Generalized additive mixed models identified a non-linear improvement in FEV1 for all workers after exposure cessation, with no plateau noted 25 years after retirement. Linear mixed effects models incorporating interaction terms identified prior endotoxin exposure (p=0.01) and male gender (p=0.002) as risk factors for impaired FEV1 improvement after exposure cessation. After adjusting for gender, smoking delayed the onset of FEV1 gain but did not affect the overall magnitude of change. CONCLUSIONS Lung function improvement after cessation of exposure to organic dust is sustained. Endotoxin exposure and male gender are risk factors for less FEV1 improvement. PMID:25666844

  12. Surfactant protein A, exposure to endotoxin, and asthma in garbage collectors and in wastewater workers.

    PubMed

    Widmeier, Susanne; Bernard, Alfred; Tschopp, Alois; Jeggli, Stefan; Dumont, Xavier; Hilfiker, Silvia; Oppliger, Anne; Hotz, Philippe

    2007-04-01

    Endotoxin causes an inflammation at the bronchial and alveolar level. The inflammation-induced increase in permeability of the bronchoalveolar epithelial barrier is supposed to cause a leakage of pneumoproteins. Therefore, their concentrations are expected to increase in the bloodstream. This study aimed at examining the association between occupational exposure to endotoxin and a serum pneumoprotein, surfactant protein A, to look for nonoccupational factors capable of confounding this association, and examine the relation between surfactant protein A and spirometry. There were 369 control subjects, 325 wastewater workers, and 84 garbage collectors in the study. Exposure to endotoxin was assessed through personal sampling and the Limulus amebocytes lysate assay. Surfactant protein A was determined by an in house sandwich enzyme-linked immunosorbent assay (ELISA) in 697 subjects. Clinical and smoking history were ascertained and spirometry carried out according to American Thoracic Society criteria. Multiple linear regression was used for statistical analysis. Exposure was fairly high during some tasks in wastewater workers but did not influence surfactant protein A. Surfactant protein A was lower in asthmatics. Interindividual variability was large. No correlation with spirometry was found. Endotoxin has no effect on surfactant protein A at these endotoxin levels and serum surfactant protein A does not correlate with spirometry. The decreased surfactant protein A secretion in asthmatics requires further study.

  13. Cotton dust and endotoxin exposure-response relationships in cotton textile workers

    SciTech Connect

    Kennedy, S.M.; Christiani, D.C.; Eisen, E.A.; Wegman, D.H.; Greaves, I.A.; Olenchock, S.A.; Ye, T.T.; Lu, P.L.

    1987-01-01

    Endotoxin exposure has been implicated in the etiology of lung disease in cotton workers. We investigated this potential relationship in 443 cotton workers from 2 factories in Shanghai and 439 control subjects from a nearby silk mill. A respiratory questionnaire was administered and pre- and postshift forced expiratory volume (FVC) and flow in one second (FEV1) were determined for each worker. Multiple area air samples were analyzed for total elutriated dust concentration (range: 0.15 to 2.5 mg/m3) and endotoxin (range: 0.002 to 0.55 microgram U.S. Reference Endotoxin/m3). The cotton worker population was stratified by current and cumulative dust or endotoxin exposure. Groups were compared for FEV1, FVC, FEV1/FVC%, % change in FEV1 over the shift (delta FEV1%), and prevalences of chronic bronchitis and byssinosis, and linear and logistic regression models were constructed. No dose-response relationships were demonstrated comparing dust concentration to any pulmonary function or symptom variable. A dose-response trend was seen with the current endotoxin level and FEV1, delta FEV1%, and the prevalence of byssinosis and chronic bronchitis, except for the highest exposure level group in which a reversal of the trend was seen. The regression coefficients for current endotoxin exposure were significant (p less than 0.05) in the models for FEV1 and chronic bronchitis but not in the models for delta FEV1% (i.e., acute change in FEV1) or byssinosis prevalence. The coefficient for dust level was never significant in the models.

  14. A review of drinking-water-associated endotoxin, including potential routes of human exposure.

    PubMed

    Anderson, William B; Slawson, Robin M; Mayfield, Colin I

    2002-07-01

    In the past decade efforts have been made to reduce the formation of harmful disinfection byproducts during the treatment and distribution of drinking water. This has been accomplished in part by the introduction of processes that involve the deliberate encouragement of indigenous biofilm growth in filters. In a controlled environment, such as a filter, these biofilms remove compounds that would otherwise be available as disinfection byproduct precursors or support uncontrolled biological activity in distribution systems. In the absence of exposure to chlorinated water, most biofilm bacteria are gram negative and have an outer layer that contains endotoxin. To date, outbreaks of waterborne endotoxin-related illness attributable to contamination of water used in hemodialysis procedures have been only infrequently documented, and occurrences linked to ingestion or through dermal abrasions could not be located. However, a less obvious conduit, that of inhalation, has been described in association with aerosolized water droplets. This review summarizes documented drinking-water-associated incidents of endotoxin exposure attributable to hemodialysis and inhalation. Typical endotoxin levels in water and conditions under which substantial quantities can enter drinking water distribution systems are identified. It would appear that endotoxin originating in tap water can be inhaled but at present there is insufficient information available to quantify potential health risks.

  15. Chronic endotoxin exposure produces airflow obstruction and lung dendritic cell expansion.

    PubMed

    Lai, Peggy S; Fresco, Jennifer M; Pinilla, Miguel A; Macias, Alvaro A; Brown, Ronald D; Englert, Joshua A; Hofmann, Oliver; Lederer, James A; Hide, Winston; Christiani, David C; Cernadas, Manuela; Baron, Rebecca M

    2012-08-01

    Little is known about the mechanisms of persistent airflow obstruction that result from chronic occupational endotoxin exposure. We sought to analyze the inflammatory response underlying persistent airflow obstruction as a result of chronic occupational endotoxin exposure. We developed a murine model of daily inhaled endotoxin for periods of 5 days to 8 weeks. We analyzed physiologic lung dysfunction, lung histology, bronchoalveolar lavage fluid and total lung homogenate inflammatory cell and cytokine profiles, and pulmonary gene expression profiles. We observed an increase in airway hyperresponsiveness as a result of chronic endotoxin exposure. After 8 weeks, the mice exhibited an increase in bronchoalveolar lavage and lung neutrophils that correlated with an increase in proinflammatory cytokines. Detailed analyses of inflammatory cell subsets revealed an expansion of dendritic cells (DCs), and in particular, proinflammatory DCs, with a reduced percentage of macrophages. Gene expression profiling revealed the up-regulation of a panel of genes that was consistent with DC recruitment, and lung histology revealed an accumulation of DCs in inflammatory aggregates around the airways in 8-week-exposed animals. Repeated, low-dose LPS inhalation, which mirrors occupational exposure, resulted in airway hyperresponsiveness, associated with a failure to resolve the proinflammatory response, an inverted macrophage to DC ratio, and a significant rise in the inflammatory DC population. These findings point to a novel underlying mechanism of airflow obstruction as a result of occupational LPS exposure, and suggest molecular and cellular targets for therapeutic development.

  16. Personal Exposure to Particulate Matter and Endotoxin in California Dairy Workers

    NASA Astrophysics Data System (ADS)

    Garcia, Johnny

    The average number of cows per dairy has increased over the last thirty years, with little known about how this increase may impact occupational exposure. Thirteen California dairies and 226 workers participated in this study throughout the 2008 summer months. Particulate Matter (PM) and endotoxin concentrations were quantified using ambient area based and personal air samplers. Two size fractions were collected, Total Suspended Particulate matter (TSP) and PM 2.5. Differences across dairies were evaluated by placing area based integrated air samplers in established locations on the dairies, e.g. milking parlor, drylot corral, and freestall barns. The workers occupational exposure was quantified using personal air samplers. We analyzed concentrations along with the time workers spent conducting specific job tasks during their shift to identify high exposure job tasks. Biological and chemical analytical methods were employed to ascertain endotoxin concentrations in personal and area based air samples. Recombinant factor C assays (rFC) were used to analyze biologically active endotoxin and gas chromatography coupled with mass spectrometry in tandem (GC-MS/MS) was used to quantify total endotoxin. The PM2.5 concentrations ranged from 2-116 mug/m3 for ambient area concentration and 7-495 mug/m3 for personal concentrations while TSP concentrations ranged from 74-1690 mug/m3 for area ambient concentrations and 191-4950 mug/m3 for personal concentrations. Biologically active endotoxin concentrations in the TSP size fraction from ambient area based samples ranged from 11-2095 EU/m3 and 45-2061 EU/m3 for personal samples. Total endotoxin in the TSP size fraction ranged from 75-10,166 pmol/m3 for area based samples and 34-11,689 pmol/m3 for personal samples. Drylot corrals were found to have higher sample mean concentrations when compared to other locations on the dairies for PM and endotoxin. Re-bedding, of the freestalls, was found to consistently lead to higher personal

  17. Exposures to thoracic particulate matter, endotoxin, and glucan during post-Hurricane Katrina restoration work, New Orleans 2005-2012.

    PubMed

    Rando, Roy J; Kwon, Cheol-Woong; Lefante, John J

    2014-01-01

    In the aftermath of Hurricane Katrina, which devastated the city of New Orleans in August 2005, restoration workers were at risk for respiratory illness from exposure to airborne particles and microbial agents. In support of an epidemiologic investigation of this risk, an exposure assessment for restoration work activities (demolition, trash & debris management, landscape restoration, sewer/waterline repair, and mold remediation) was performed from 2005 to 2012. For 2005 and 2006, Occupational Safety and Health Administration (OSHA) data (n = 730) for personal and area monitoring of total and respirable dust exposures of restoration workers were accessed and analyzed. The most significant exposures were for demolition work, with average respirable dust exposures in 2005 above the action level of 2.5 mg/m(3) and 17.6% of exposures exceeding the permissible exposure limit (PEL) (5 mg/m(3)). Additional personal and area monitoring for thoracic particulate matter was performed from 2007 to 2012 (n = 774) and samples were assayed for endotoxin and (1→3, 1→6)-β-D-glucan (n = 202). In order to integrate the OSHA data with the later monitoring data, three independent predictive models were developed to convert total and respirable dust measures into the equivalent thoracic dust. The three models were not statistically different and the modeling results were in good agreement with an overall coefficient of variation of 16% for the thoracic dust means across work activities estimated by each of the three models. Overall, thoracic dust exposure levels decreased by about an order of magnitude within the first year after Katrina and then more gradually declined and stabilized through 2012. Estimated average exposures to endotoxin and microbial glucan in 2005 were as high as 256 EU/m(3) and 118 μg/m(3), respectively, and likewise were seen to decrease dramatically and stabilize after 2005. The results of this exposure assessment support previously published reports of

  18. Exposures to thoracic particulate matter, endotoxin, and glucan during post-Hurricane Katrina restoration work, New Orleans 2005-2012.

    PubMed

    Rando, Roy J; Kwon, Cheol-Woong; Lefante, John J

    2014-01-01

    In the aftermath of Hurricane Katrina, which devastated the city of New Orleans in August 2005, restoration workers were at risk for respiratory illness from exposure to airborne particles and microbial agents. In support of an epidemiologic investigation of this risk, an exposure assessment for restoration work activities (demolition, trash & debris management, landscape restoration, sewer/waterline repair, and mold remediation) was performed from 2005 to 2012. For 2005 and 2006, Occupational Safety and Health Administration (OSHA) data (n = 730) for personal and area monitoring of total and respirable dust exposures of restoration workers were accessed and analyzed. The most significant exposures were for demolition work, with average respirable dust exposures in 2005 above the action level of 2.5 mg/m(3) and 17.6% of exposures exceeding the permissible exposure limit (PEL) (5 mg/m(3)). Additional personal and area monitoring for thoracic particulate matter was performed from 2007 to 2012 (n = 774) and samples were assayed for endotoxin and (1→3, 1→6)-β-D-glucan (n = 202). In order to integrate the OSHA data with the later monitoring data, three independent predictive models were developed to convert total and respirable dust measures into the equivalent thoracic dust. The three models were not statistically different and the modeling results were in good agreement with an overall coefficient of variation of 16% for the thoracic dust means across work activities estimated by each of the three models. Overall, thoracic dust exposure levels decreased by about an order of magnitude within the first year after Katrina and then more gradually declined and stabilized through 2012. Estimated average exposures to endotoxin and microbial glucan in 2005 were as high as 256 EU/m(3) and 118 μg/m(3), respectively, and likewise were seen to decrease dramatically and stabilize after 2005. The results of this exposure assessment support previously published reports of

  19. Assessment of Airborne Exposures and Health in Flooded Homes Undergoing Renovation

    PubMed Central

    Hoppe, Kimberly A.; Metwali, Nervana; Perry, Sarah Spencer; Hart, Tom; Kostle, Pamela A.; Thorne, Peter S.

    2012-01-01

    In June 2008, the Cedar River crested flooding more than 5,000 Cedar Rapids homes. Residents whose homes were flooded were invited to participate in this study. Household assessments and resident interviews were conducted between November 2008 and April 2009. We characterized exposures and symptoms experienced by individuals inhabiting 73 flood-damaged homes. Active air sampling and passive electrostatic dust collectors were used to assess exposures to: culturable mold, culturable bacteria, fungal spores, inhalable particulate matter (iPM), endotoxin, glucans, allergens, lead, asbestos, radon, carbon dioxide, and carbon monoxide. Wall moisture levels and relative humidity were also measured. Exposures and questionnaire-based health assessments were compared at two levels of remediation, in-progress and completed. Homes with remediation in-progress (n=24), as compared to the completed homes (n=49), had significantly higher airborne concentrations of mold, bacteria, iPM, endotoxin and glucan. Residents of in-progress homes had a significantly higher prevalence of doctor diagnosed allergies (adjusted OR=3.08; 95%CI: 1.05–9.02) and all residents had elevated prevalence of self-reported wheeze (adjusted OR=3.77; 95%CI: 2.06–6.92) and prescription medication use for breathing problems (adjusted OR=1.38; 95%CI: 1.01–1.88) after the flood as compared to before. Proper post-flood remediation led to improved air quality and lower exposures among residents living in flooded homes. PMID:22519834

  20. Chronic intrauterine exposure to endotoxin does not alter fetal nephron number or glomerular size.

    PubMed

    Ryan, Danica; Atik, Anzari; De Matteo, Robert; Harding, Richard; Black, Mary J

    2013-11-01

    A reduced nephron endowment early in life adversely impacts on long-term functional reserve in the kidney. A recent study has shown that acute exposure to chorioamnionitis during late gestation can adversely impact on nephrogenesis. The present study aimed to examine the effects of chronic, low-dose endotoxin exposure in utero, during the period of nephrogenesis, on nephron number and glomerular size in preterm lambs. Ewes were administered either endotoxin (lipopolysaccharide; 1 mg/day) or saline at 110-133 days of gestation (term approximately 147 days) via surgically implanted osmotic minipumps within the amniotic cavity. The ewes were induced to deliver preterm at 133 days gestation and the kidneys of the lambs were analysed at 8 weeks after term-equivalent age. Nephron number per kidney was determined using a combined optical disector and fractionator stereological approach; renal corpuscle size was also measured stereologically. At 8 weeks after term-equivalent age there was no significant effect of in utero exposure to endotoxin on bodyweight or kidney weight and there were no significant differences in nephron number, nephron density or renal corpuscle volume between groups. We conclude that chronic intrauterine inflammation during the period of nephrogenesis may not adversely impact on the number of nephrons formed within the kidney or on the volume of the renal corpuscle.

  1. Exposure to airborne asbestos in buildings

    SciTech Connect

    Lee, R.J.; Van Orden, D.R.; Corn, M.; Crump, K.S. )

    1992-08-01

    The concentration of airborne asbestos in buildings and its implication for the health of building occupants is a major public health issue. A total of 2892 air samples from 315 public, commercial, residential, school, and university buildings has been analyzed by transmission electron microscopy. The buildings that were surveyed were the subject of litigation related to suits alleging the general building occupants were exposed to a potential health hazard as a result of exposure to the presence of asbestos containing materials (ACM). The average concentration of all asbestos structures was 0.02 structures/ml (s/ml) and the average concentration of asbestos greater than or equal to 5 microns long was 0.00013 fibers/ml (f/ml). The concentration of asbestos was higher in schools than in other buildings. In 48% of indoor samples and 75% of outdoor samples, no asbestos fibers were detected. The observed airborne concentration in 74% of the indoor samples and 96% of the outdoor samples is below the Asbestos Hazard Emergency Response Act clearance level of 0.01 s/ml. Finally, using those fibers which could be seen optically, all indoor samples and all outdoor samples are below the Occupational Safety and Health Administration permissible exposure level of 0.1 f/ml for fibers greater than or equal to 5 microns in length. These results provide substantive verification of the findings of the U.S. Environmental Protection Agency public building study which found very low ambient concentrations of asbestos fibers in buildings with ACM, irrespective of the condition of the material in the buildings.

  2. Spatial variations in airborne microorganism and endotoxin concentrations at green waste composting facilities.

    PubMed

    Pankhurst, L J; Deacon, L J; Liu, J; Drew, G H; Hayes, E T; Jackson, S; Longhurst, P J; Longhurst, J W S; Pollard, S J T; Tyrrel, S F

    2011-09-01

    The emission and dispersal of bioaerosols from open-air commercial composting facilities continues to be contentious. A meta-dataset enumerating cultivable microorganism emission and downwind concentrations is not yet available. A dataset derived from repeated and replicated field studies over a period of two years at two commercial composting facilities is presented. The data characterises patterns in Aspergillus fumigatus, actinomycetes, Gram-negative bacteria and endotoxin emission and downwind concentrations. For all bioaerosols, compost agitation activities had a significant impact on concentrations; levels were variable up to 600 m downwind from site. Bioaerosols declined rapidly from source and exhibited a secondary peak 100-150 m from site boundary. All bioaerosols were found downwind from site in elevated concentrations. Compared to those found 100 m upwind, levels were significantly higher at 180 m downwind for A. fumigatus; at 300-400 m for actinomycetes and Gram negative bacteria, and at 100 m for endotoxins. Periodically, elevated concentrations could be found for all bioaerosols at distances further downwind. The evidence provided by this data set provides operators and regulators of facilities with reliable data to inform the location, risk assessment and bioaerosol sampling strategies of commercial composting facilities.

  3. Spatial variations in airborne microorganism and endotoxin concentrations at green waste composting facilities.

    PubMed

    Pankhurst, L J; Deacon, L J; Liu, J; Drew, G H; Hayes, E T; Jackson, S; Longhurst, P J; Longhurst, J W S; Pollard, S J T; Tyrrel, S F

    2011-09-01

    The emission and dispersal of bioaerosols from open-air commercial composting facilities continues to be contentious. A meta-dataset enumerating cultivable microorganism emission and downwind concentrations is not yet available. A dataset derived from repeated and replicated field studies over a period of two years at two commercial composting facilities is presented. The data characterises patterns in Aspergillus fumigatus, actinomycetes, Gram-negative bacteria and endotoxin emission and downwind concentrations. For all bioaerosols, compost agitation activities had a significant impact on concentrations; levels were variable up to 600 m downwind from site. Bioaerosols declined rapidly from source and exhibited a secondary peak 100-150 m from site boundary. All bioaerosols were found downwind from site in elevated concentrations. Compared to those found 100 m upwind, levels were significantly higher at 180 m downwind for A. fumigatus; at 300-400 m for actinomycetes and Gram negative bacteria, and at 100 m for endotoxins. Periodically, elevated concentrations could be found for all bioaerosols at distances further downwind. The evidence provided by this data set provides operators and regulators of facilities with reliable data to inform the location, risk assessment and bioaerosol sampling strategies of commercial composting facilities. PMID:21737345

  4. Measurement of endotoxins in bioaerosols at workplace: a critical review of literature and a standardization issue.

    PubMed

    Duquenne, Philippe; Marchand, Geneviève; Duchaine, Caroline

    2013-03-01

    Endotoxins are lipopolysaccharides found in the outer membrane of most Gram-negative bacteria and cyanobacteria. Worker exposure to endotoxins has been shown in a number of work situations and is associated with both respiratory and systemic pathologies. The lack of an occupational exposure limit is mainly due to the absence of a standard protocol at the international level for sampling and analyzing airborne endotoxins. The bibliographic review in this article takes an exhaustive look at the current knowledge on measuring airborne endotoxins. It shows that, despite several reference documents at the international level, the methods used to measure endotoxin exposure differ considerably from one laboratory to another. Standardization is necessary to reduce interlaboratory variability and, ultimately, to improve the use of interstudy data. The bibliographic review presents the current status of standardization for airborne endotoxin measurement methods in the workplace and summarizes areas for further research. This article is both a reference document for all operators wishing to use such methods and a working document to build international consensus around the measurement of airborne endotoxins.

  5. Endotoxin in Size-Separated Metal Working Fluid Aerosol Particles.

    PubMed

    Dahlman-Höglund, Anna; Lindgren, Åsa; Mattsby-Baltzer, Inger

    2016-08-01

    Patients with airway symptoms working in metal working industries are increasing, despite efforts to improve the environmental air surrounding the machines. Our aim was to analyse the amount of endotoxin in size-separated airborne particles of metal working fluid (MWF) aerosol, by using the personal sampler Sioutas cascade impactor, to compare filter types, and to compare the concentration of airborne endotoxin to that of the corresponding MWFs. In a pilot field study, aerosols were collected in two separate machine halls on totally 10 occasions, using glass fibre and polytetrafluoroethylene (PTFE) filters in parallel at each station. Airborne endotoxin was distributed over all size fractions. While a major part was found in the largest size fraction (72%, 2.5-10 µm), up to 8% of the airborne endotoxin was detected in the smallest size fraction (<0.25 µm). Comparing the efficiency of the filter types, a significantly higher median endotoxin level was found with glass fibres filters collecting the largest particle-size fraction (1.2-fold) and with PTFE filters collecting the smallest ones (5-fold). The levels of endotoxin in the size-separated airborne particle fractions correlated to those of the MWFs supporting the aerosol-generating machines. Our study indicates that a significant part of inhalable aerosols of MWFs consists of endotoxin-containing particles below the size of intact bacteria, and thus small enough to readily reach the deepest part of the lung. Combined with other chemical irritants of the MWF, exposure to MWF aerosols containing endotoxin pose a risk to respiratory health problems. PMID:27268595

  6. Occupational Exposures and Chronic Kidney Disease: Possible associations with endotoxin and ultrafine particles

    PubMed Central

    Sponholtz, Todd R.; Sandler, Dale P.; Parks, Christine G.; Applebaum, Katie M.

    2015-01-01

    Background Chronic kidney disease (CKD) carries a high public health burden yet there is limited research on occupational factors, which are examined in this retrospective case-control study. Methods Newly diagnosed cases of CKD (n=547) and controls (n=508) from North Carolina provided detailed work histories in telephone interviews. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results There was heterogeneity in the association of CKD and agricultural work, with crop production associated with increased risk and work with livestock associated with decreased risk. Work with cutting/cooling/lubricating oils was associated with a reduced risk. CKD risk was increased for working in dusty conditions. Conclusions CKD risk was reduced in subjects with occupational exposures previously reported to involve endotoxin exposure. Further, exposure to dusty conditions was consistently associated with increased risk of glomerulonephritis across industry, suggesting that research on CKD and ultrafine particulates is needed. PMID:26572099

  7. Endotoxin levels in homes and classrooms of Dutch school children and respiratory health.

    PubMed

    Jacobs, José H; Krop, Esmeralda J M; de Wind, Siegfried; Spithoven, Jack; Heederik, Dick J J

    2013-08-01

    Several studies describe indoor pollutant exposure in homes and to a lesser extent in schools. Population studies that include both environments are sparse. This study aims to assess endotoxin levels in primary schools and homes of children. Endotoxin was also studied in relation to asthma and sensitisation. 10 schools with (index) and without (reference) dampness were selected, based on reports and inspections. Cases and controls were selected from 169 homes based on the presence or absence of asthma-like symptoms of children. Classroom and bedroom airborne settled dust was sampled using electrostatic dust fall collectors. Average endotoxin levels in schools ranged from 2178 to 6914 endotoxin units (EU)·m(-2) per week compared with 462-1285 EU·m(-2) per week in homes. After mutual adjustment for home and school endotoxin, school endotoxin was positively associated with nonatopic asthma (OR 1.11, 95% CI 0.97-1.27), while no associations with endotoxin were found at home. The high endotoxin levels in schools compared with homes indicate that exposure at school can contribute considerably to environmental endotoxin exposure of children and teachers. Our results also suggest that endotoxin in schools may be associated with nonatopic asthmatic symptoms in pupils, although the results require reproduction because of the modest sample size.

  8. Point-of-sale glass bottle recycling: indoor airborne exposures and symptoms among employees

    PubMed Central

    Kennedy, S; Copes, R; Bartlett, K; Brauer, M

    2004-01-01

    Aims: To assess the impact of newly introduced point-of-sale glass bottle recycling on indoor air quality and employee health. Methods: Airborne exposures and both chronic and acute respiratory and somatic symptoms were surveyed among 226 employees at 36 randomly selected liquor stores with bottle recycling and in-house glass breaking. Each store was visited twice; between visits glass breaking was discontinued for one month in half the stores (selected at random), although bottles were still collected and stored on site. Rates of chronic symptoms were compared to an external, unexposed control population. Results: Geometric mean exposure levels were 0.18 mg/m3 for inhalable particulate matter and 3.6 EU/m3 for endotoxin (270 personal samples); 1064 CFU/m3 for viable fungi (648 area samples). Fungal levels were associated with visibly mouldy bottles being broken, outdoor fungal counts, and uncovered glass bins. Exposures were not altered by the intervention of shutting down glass breaking machinery. Compared to controls, employees reported more work related chronic chest tightness and chronic nasal symptoms. Acute chest symptoms were associated with breaking visibly mouldy bottles, but not with measured fungal counts. Inhalable particulate matter levels >0.2 mg/m3 were associated with acute upper airway irritation. Somatic symptoms were associated with measures of psychosocial job strain. Conclusion: Results suggest that this type of recycling programme may generate fungal exposures sufficient to elicit upper airway and chest symptoms. PMID:15208380

  9. Exposure to bacterial endotoxin generates a distinct strain of α-synuclein fibril

    PubMed Central

    Kim, Changyoun; Lv, Guohua; Lee, Jun Sung; Jung, Byung Chul; Masuda-Suzukake, Masami; Hong, Chul-Suk; Valera, Elvira; Lee, He-Jin; Paik, Seung R.; Hasegawa, Masato; Masliah, Eliezer; Eliezer, David; Lee, Seung-Jae

    2016-01-01

    A single amyloidogenic protein is implicated in multiple neurological diseases and capable of generating a number of aggregate “strains” with distinct structures. Among the amyloidogenic proteins, α-synuclein generates multiple patterns of proteinopathies in a group of diseases, such as Parkinson disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). However, the link between specific conformations and distinct pathologies, the key concept of the strain hypothesis, remains elusive. Here we show that in the presence of bacterial endotoxin, lipopolysaccharide (LPS), α-synuclein generated a self-renewable, structurally distinct fibril strain that consistently induced specific patterns of synucleinopathies in mice. These results suggest that amyloid fibrils with self-renewable structures cause distinct types of proteinopathies despite the identical primary structure and that exposure to exogenous pathogens may contribute to the diversity of synucleinopathies. PMID:27488222

  10. Exposure to bacterial endotoxin generates a distinct strain of α-synuclein fibril.

    PubMed

    Kim, Changyoun; Lv, Guohua; Lee, Jun Sung; Jung, Byung Chul; Masuda-Suzukake, Masami; Hong, Chul-Suk; Valera, Elvira; Lee, He-Jin; Paik, Seung R; Hasegawa, Masato; Masliah, Eliezer; Eliezer, David; Lee, Seung-Jae

    2016-01-01

    A single amyloidogenic protein is implicated in multiple neurological diseases and capable of generating a number of aggregate "strains" with distinct structures. Among the amyloidogenic proteins, α-synuclein generates multiple patterns of proteinopathies in a group of diseases, such as Parkinson disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). However, the link between specific conformations and distinct pathologies, the key concept of the strain hypothesis, remains elusive. Here we show that in the presence of bacterial endotoxin, lipopolysaccharide (LPS), α-synuclein generated a self-renewable, structurally distinct fibril strain that consistently induced specific patterns of synucleinopathies in mice. These results suggest that amyloid fibrils with self-renewable structures cause distinct types of proteinopathies despite the identical primary structure and that exposure to exogenous pathogens may contribute to the diversity of synucleinopathies. PMID:27488222

  11. LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...

  12. Seasonal Changes in Endotoxin Exposure and Its Relationship to Exhaled Nitric Oxide and Exhaled Breath Condensate pH Levels in Atopic and Healthy Children

    PubMed Central

    Tung, Tao-Hsin; Tang, Chin-Sheng; Liu, Chiu-Hsin

    2013-01-01

    Endotoxin, a component of the cell walls of gram-negative bacteria, is a contaminant in organic dusts (house dust) and aerosols. In humans, small amounts of endotoxin may cause a local inflammatory response. Exhaled nitric oxide (eNO) levels, an inflammation indicator, are associated with the pH values of exhaled breath condensate (EBC). This study evaluated seasonal changes on indoor endotoxin concentrations in homes and the relationships between endotoxin exposure and eNO/EBC pH levels for healthy children and children with allergy-related respiratory diseases. In total, 34 children with allergy-related respiratory diseases and 24 healthy children were enrolled. Indoor air quality measurements and dust sample analysis for endotoxin were conducted once each season inside 58 surveyed homes. The eNO, EBC pH levels, and pulmonary function of the children were also determined. The highest endotoxin concentrations were on kitchen floors of homes of children with allergy-related respiratory diseases and healthy children, and on bedroom floors of homes of asthmatic children and healthy children. Seasonal changes existed in endotoxin concentrations in dust samples from homes of children with allergic rhinitis, with or without asthma, and in EBC pH values among healthy children and those with allergy-related respiratory diseases. Strong relationships existed between endotoxin exposure and EBC pH values in children with allergic rhinitis. PMID:23840530

  13. Thrombin generation by exposure of blood to endotoxin: a simple model to study disseminated intravascular coagulation.

    PubMed

    Stief, T W

    2006-04-01

    Pathologic disseminated intravascular coagulation (PDIC) is a serious complication in sepsis. In an in-vitro system consisting of incubation of fresh citrated blood with lipopolysaccharides (LPS) or glucans and subsequent plasma recalcification plasmatic thrombin was quantified. Five hundred microliters of freshly drawn citrated blood of healthy donors were incubated with up to 800 ng/mL LPS (Escherichia coli) or up to 80 microg/mL Zymosan A (ZyA; Candida albicans) for 30 minutes at room temperature (RT). The samples were centrifuged, and 30 microL plasma were recalcified with 1 volume or less of CaCl(2) (25 micromoles Ca(2+)/mL plasma). After 0 to 12 minutes (37 degrees C), 20 microL 2.5 M arginine, pH 8.6, were added. Thirty microliters 0.9 mM HD-CHG-Ala-Arg-pNA in 2.3 M arginine were added, and the absorbance increase at 405 nm was determined. Fifty microliters plasma were also incubated with 5 microL 250 mM CaCl2 for 5, 10, or 15 minutes (37 degrees C). Fifty microliters 2.5 M arginine stops coagulation, and 50 microL 0.77 mM HD-CHG-Ala-Arg-pNA in 2.3 M arginine starts the thrombin detection. The standard was 1 IU/mL thrombin in 7% human albumin instead of plasma. Arginine was also added in the endotoxin exposure time (EET) or in the plasma coagulation reaction time (CRT). Tissue factor (TF)-antigen and soluble CD14 were determined. LPS at blood concentrations greater than 10 ng/mL or ZyA at greater than 1 microg/mL severalfold enhance thrombin generation, when the respective plasmas are recalcified. After 30 minutes EET at RT, the thrombin activity at 12 minutes CRT generated by the addition of 200 ng/mL LPS or 20 microg/mL ZyA is approximately 200 mIU/mL compared to approximately 20 mIU/mL without addition of endotoxin, or compared to about 7 mIU/mL thrombin at 0 minutes CRT. Arginine added to blood or to plasma inhibits thrombin generation; the inhibitory concentration 50% (IC 50) is approximately 15 mM plasma concentration. Endotoxin incubation of blood

  14. Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation

    SciTech Connect

    Csako, G.; Suba, E.A.; Ahlgren, A.; Tsai, C.M.; Elin, R.J.

    1986-01-01

    The structure and function of the highly purified US reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a /sup 60/Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.

  15. Airborne particle exposure and extrinsic skin aging.

    PubMed

    Vierkötter, Andrea; Schikowski, Tamara; Ranft, Ulrich; Sugiri, Dorothea; Matsui, Mary; Krämer, Ursula; Krutmann, Jean

    2010-12-01

    For decades, extrinsic skin aging has been known to result from chronic exposure to solar radiation and, more recently, to tobacco smoke. In this study, we have assessed the influence of air pollution on skin aging in 400 Caucasian women aged 70-80 years. Skin aging was clinically assessed by means of SCINEXA (score of intrinsic and extrinsic skin aging), a validated skin aging score. Traffic-related exposure at the place of residence was determined by traffic particle emissions and by estimation of soot in fine dust. Exposure to background particle concentration was determined by measurements of ambient particles at fixed monitoring sites. The impact of air pollution on skin aging was analyzed by linear and logistic regression and adjusted for potential confounding variables. Air pollution exposure was significantly correlated to extrinsic skin aging signs, in particular to pigment spots and less pronounced to wrinkles. An increase in soot (per 0.5 × 10(-5) per m) and particles from traffic (per 475  kg per year and square km) was associated with 20% more pigment spots on forehead and cheeks. Background particle pollution, which was measured in low residential areas of the cities without busy traffic and therefore is not directly attributable to traffic but rather to other sources of particles, was also positively correlated to pigment spots on face. These results indicate that particle pollution might influence skin aging as well.

  16. Assessing human exposure to airborne pollutants: Advances and opportunities

    SciTech Connect

    Lioy, P.J. )

    1991-08-01

    A committee which was convened by the National Research Council, recently completed an analysis of new methods and technologies for assessing exposure to air pollutants. The committee identified three major ways of determining human exposure to airborne pollutants. Monitoring the air around an individual with a portable personal air sampler is, of course, the most comprehensive and most accurate. It is also the costliest and most time consuming. The second method is more indirect and involves techniques such as measuring the amount of a contaminant with a stationary monitor and extrapolating exposure by means of personal activity records or mathematical models. Exposure to carbon monoxide inside a car, for example, might be roughly calculated from the amount of time spent in the car and the quantity of carbon monoxide in the car under typical operating conditions. The third method involves biological markers as a measure of the integrated dose within the body and of past contact with pollutants. For example, a marker for airborne lead exposure can be elevated lead levels in the blood. However, this must be weighed against contributions from other media. A final and major point made in the report is the need to have accurate and realistic assessments to ensure optimal reduction of human exposure. To accomplish this, exposure assessment research should be supported by government programs. Although not stated, such research should also be supported by other sectors, including the regulated community.

  17. Exposure to airborne asbestos in thermal power plants in Mongolia

    PubMed Central

    Damiran, Naransukh; Silbergeld, Ellen K; Frank, Arthur L; Lkhasuren, Oyuntogos; Ochir, Chimedsuren; Breysse, Patrick N

    2015-01-01

    Background: Coal-fired thermal power plants (TPPs) in Mongolia use various types of asbestos-containing materials (ACMs) in thermal insulation of piping systems, furnaces, and other products. Objective: To investigate the occupational exposure of insulation workers to airborne asbestos in Mongolian power plants. Methods: Forty-seven air samples were collected from four power plants in Mongolia during the progress of insulation work. The samples were analyzed by phase contrast microscopy (PCM) and transmission electron microscopy (TEM). Results: The average phase contrast microscopy equivalent (PCME) asbestos fiber concentration was 0.93 f/cm3. Sixteen of the 41 personal and one of the area samples exceeded the United States Occupational Safety and Health Administration (US OSHA) short-term exposure limit of 1.0 f/cm3. If it is assumed that the short-term samples collected are representative of full-shift exposure, then the exposures are approximately 10 times higher than the US OSHA 8-hour permissible exposure limit of 0.1 f/cm3. Conclusion: Power plant insulation workers are exposed to airborne asbestos at concentrations that exceed the US OSHA Permissible Exposure Limit. Action to mitigate the risks should be taken in Mongolia. PMID:25730489

  18. New Methods for Personal Exposure Monitoring for Airborne Particles

    PubMed Central

    Koehler, Kirsten A.; Peters, Thomas

    2016-01-01

    Airborne particles have been associated with a range of adverse cardiopulmonary outcomes, which has driven its monitoring at stationary, central sites throughout the world. Individual exposures, however, can differ substantially from concentrations measured at central sites due to spatial variability across a region and sources unique to the individual, such as cooking or cleaning in homes, traffic emissions during commutes, and widely varying sources encountered at work. Personal monitoring with small, battery-powered instruments enables the measurement of an individual’s exposure as they go about their daily activities. Personal monitoring can substantially reduce exposure misclassification and improve the power to detect relationships between particulate pollution and adverse health outcomes. By partitioning exposures to known locations and sources, it may be possible to account for variable toxicity of different sources. This review outlines recent advances in the field of personal exposure assessment for particulate pollution. Advances in battery technology have improved the feasibility of 24-hour monitoring, providing the ability to more completely attribute exposures to microenvironment (e.g., work, home, commute). New metrics to evaluate the relationship between particulate matter and health are also being considered, including particle number concentration, particle composition measures, and particle oxidative load. Such metrics provide opportunities to develop more precise associations between airborne particles and health and may provide opportunities for more effective regulations. PMID:26385477

  19. Airborne exposure patterns from a passenger source in aircraft cabins

    PubMed Central

    Bennett, James S.; Jones, Byron W.; Hosni, Mohammad H.; Zhang, Yuanhui; Topmiller, Jennifer L.; Dietrich, Watts L.

    2015-01-01

    Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins. PMID:26526769

  20. Airborne exposure patterns from a passenger source in aircraft cabins.

    PubMed

    Bennett, James S; Jones, Byron W; Hosni, Mohammad H; Zhang, Yuanhui; Topmiller, Jennifer L; Dietrich, Watts L

    2013-01-01

    Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins. PMID:26526769

  1. Health effects of airborne exposures from concentrated animal feeding operations.

    PubMed

    Heederik, Dick; Sigsgaard, Torben; Thorne, Peter S; Kline, Joel N; Avery, Rachel; Bønløkke, Jakob H; Chrischilles, Elizabeth A; Dosman, James A; Duchaine, Caroline; Kirkhorn, Steven R; Kulhankova, Katarina; Merchant, James A

    2007-02-01

    Toxic gases, vapors, and particles are emitted from concentrated animal feeding operations (CAFOs) into the general environment. These include ammonia, hydrogen sulfide, carbon dioxide, malodorous vapors, and particles contaminated with a wide range of microorganisms. Little is known about the health risks of exposure to these agents for people living in the surrounding areas. Malodor is one of the predominant concerns, and there is evidence that psychophysiologic changes may occur as a result of exposure to malodorous compounds. There is a paucity of data regarding community adverse health effects related to low-level gas and particulate emissions. Most information comes from studies among workers in CAFO installations. Research over the last decades has shown that microbial exposures, especially endotoxin exposure, are related to deleterious respiratory health effects, of which cross-shift lung function decline and accelerated decline over time are the most pronounced effects. Studies in naïve subjects and workers have shown respiratory inflammatory responses related to the microbial load. This working group, which was part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards-Searching for Solutions, concluded that there is a great need to evaluate health effects from exposures to the toxic gases, vapors, and particles emitted into the general environment by CAFOs. Research should focus not only on nuisance and odors but also on potential health effects from microbial exposures, concentrating on susceptible subgroups, especially asthmatic children and the elderly, since these exposures have been shown to be related to respiratory health effects among workers in CAFOs. PMID:17384782

  2. Health Effects of Airborne Exposures from Concentrated Animal Feeding Operations

    PubMed Central

    Heederik, Dick; Sigsgaard, Torben; Thorne, Peter S.; Kline, Joel N.; Avery, Rachel; Bønløkke, Jakob H.; Chrischilles, Elizabeth A.; Dosman, James A.; Duchaine, Caroline; Kirkhorn, Steven R.; Kulhankova, Katarina; Merchant, James A.

    2007-01-01

    Toxic gases, vapors, and particles are emitted from concentrated animal feeding operations (CAFOs) into the general environment. These include ammonia, hydrogen sulfide, carbon dioxide, malodorous vapors, and particles contaminated with a wide range of microorganisms. Little is known about the health risks of exposure to these agents for people living in the surrounding areas. Malodor is one of the predominant concerns, and there is evidence that psychophysiologic changes may occur as a result of exposure to malodorous compounds. There is a paucity of data regarding community adverse health effects related to low-level gas and particulate emissions. Most information comes from studies among workers in CAFO installations. Research over the last decades has shown that microbial exposures, especially endotoxin exposure, are related to deleterious respiratory health effects, of which cross-shift lung function decline and accelerated decline over time are the most pronounced effects. Studies in naïve subjects and workers have shown respiratory inflammatory responses related to the microbial load. This working group, which was part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards—Searching for Solutions, concluded that there is a great need to evaluate health effects from exposures to the toxic gases, vapors, and particles emitted into the general environment by CAFOs. Research should focus not only on nuisance and odors but also on potential health effects from microbial exposures, concentrating on susceptible subgroups, especially asthmatic children and the elderly, since these exposures have been shown to be related to respiratory health effects among workers in CAFOs. PMID:17384782

  3. Retrospective exposure assessment to airborne asbestos among power industry workers

    PubMed Central

    2010-01-01

    Background A method of individually assessing former exposure to asbestos fibres is a precondition of risk-differentiated health surveillance. The main aims of our study were to assess former levels of airborne asbestos exposure in the power industry in Germany and to propose a basic strategy for health surveillance and the early detection of asbestos related diseases. Methods Between March 2002 and the end of 2006, we conducted a retrospective questionnaire based survey of occupational tasks and exposures with airborne asbestos fibres in a cohort of 8632 formerly asbestos exposed power industry workers. The data on exposure and occupation were entered into a specially designed computer programme, based on ambient monitoring of airborne asbestos fibre concentrations. The cumulative asbestos exposure was expressed as the product of the eight-hour time weighted average and the total duration of exposure in fibre years (fibres/cubic centimetre-years). Results Data of 7775 (90% of the total) participants working in installations for power generation, power distribution or gas supply could be evaluated. The power generation group (n = 5284) had a mean age of 56 years, were exposed for 20 years and had an average cumulative asbestos exposure of 42 fibre years. The occupational group of "metalworkers" (n = 1600) had the highest mean value of 79 fibre years. The corresponding results for the power distribution group (n = 2491) were a mean age of 45 years, a mean exposure duration of 12 years and an average cumulative asbestos exposure of only 2.5 fibre years. The gas supply workers (n = 512) had a mean age of 54 years and a mean duration of exposure of 15 years. Conclusions While the surveyed cohort as a whole was heavily exposed to asbestos dust, the power distribution group had a mean cumulative exposure of only 6% of that found in the power generation group. Based on the presented data, risk-differentiated disease surveillance focusing on metalworkers and electricians

  4. Exposure to airborne allergens: a review of sampling methods.

    PubMed

    Renström, Anne

    2002-10-01

    A number of methods are used to assess exposure to high-molecular weight allergens. In the occupational setting, airborne dust is often collected on filters using pumps, the filters are eluted and allergen content in the eluate analysed using immunoassays. Collecting inhalable dust using person-carried pumps may be considered the gold standard. Other allergen sampling methods are available. Recently, a method that collects nasally inhaled dust on adhesive surfaces within nasal samplers has been developed. Allergen content can be analysed in eluates using sensitive enzyme immunoassays, or allergen-bearing particles can be immunostained using antibodies, and studied under the microscope. Settling airborne dust can be collected in petri dishes, a cheap and simple method that has been utilised in large-scale exposure studies. Collection of reservoir dust from surfaces using vacuum cleaners with a dust collector is commonly used to measure pet or mite allergens in homes. The sampling methods differ in properties and relevance to personal allergen exposure. Since methods for all steps from sampling to analysis differ between laboratories, determining occupational exposure limits for protein allergens is today unfeasible. A general standardisation of methods is needed.

  5. Lung cancer and occupational exposures other than cotton dust and endotoxin among women textile workers in Shanghai, China

    PubMed Central

    Checkoway, H; Ray, R M; Lundin, J I; Astrakianakis, G; Seixas, N S; Camp, J E; Wernli, K J; Fitzgibbons, E D; Li, W; Feng, Z; Gao, D L; Thomas, D B

    2010-01-01

    Objectives Numerous epidemiological studies of lung cancer among textile workers worldwide consistently indicate reduced risks related to cotton dust exposure, presumably due to endotoxin contamination. Our objective was to investigate associations with other exposures potentially related to lung cancer, including wool and synthetic fibre dusts, formaldehyde, silica, dyes and metals, that have only been studied to a limited extent in the textile industry. Methods We conducted a cas–ecohort study nested within a cohort of 267 400 women textile workers in Shanghai, China. We compared work assignments and exposure histories of 628 incident lung cancer cases, diagnosed during 1989–1998, with those of a reference subcohort of 3188 workers. We reconstructed exposures with a job–exposure matrix developed specifically for textile factories. Cox proportional hazards modelling was applied to estimate age/smoking-adjusted relative risks (hazard ratios) and risk gradients associated with job assignments and specific agents other than cotton dust and endotoxin. Results No associations were observed for lung cancer with wool, silk or synthetic fibre dusts, or with other agents. However, increased risks, although statistically imprecise, were noted for ≥10 years’ exposures to silica (adjusted HR 3.5, 95% CI 1.0 to 13) and ≥10 years’ exposures to formaldehyde (adjusted HR 2.1, 95% CI 0.4 to 11). Conclusions Exposures to silica and formaldehyde, although not widespread among the cohort, may have increased lung cancer risk. Silica is an established human lung carcinogen, whereas there is only weak prior evidence supporting an association with formaldehyde. Both exposures warrant consideration as potential lung carcinogens in textile manufacturing. PMID:21131604

  6. 30 CFR 57.5005 - Control of exposure to airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and use shall meet the following minimum requirements: (a) Respirators approved by NIOSH under 42 CFR... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Underground § 57.5005 Control of exposure to airborne contaminants. Control of employee exposure to...

  7. Endotoxins in cotton: washing effects and size distribution

    SciTech Connect

    Olenchock, S.A.; Mull, J.C.; Jones, W.G.

    1983-01-01

    Endotoxin contamination was measured in washed and unwashed cottons from three distinct growing areas, California, Mississippi, and Texas. The data show differences in endotoxin contamination based upon the geographic source of the cotton. It is also shown that washing bulk cotton before the carding process results in lower endotoxin in the cotton dust. Washing conditions can affect the endotoxin levels, and all size fractions of the airborne dust contain quantifiable endotoxin contamination. Endotoxin analyses provide a simple and reliable method for monitoring the cleanliness of cotton or airborne cotton dusts.

  8. Airborne occupational exposures and risk of oesophageal and cardia adenocarcinoma

    PubMed Central

    Jansson, C; Plato, N; Johansson, A L V; Nyrén, O; Lagergren, J

    2006-01-01

    Background The reasons for the increasing incidence of and strong male predominance in patients with oesophageal and cardia adenocarcinoma remain unclear. The authors hypothesised that airborne occupational exposures in male dominated industries might contribute. Methods In a nationwide Swedish population based case control study, 189 and 262 cases of oesophageal and cardia adenocarcinoma respectively, 167 cases of oesophageal squamous cell carcinoma, and 820 frequency matched controls underwent personal interviews. Based on each study participant's lifetime occupational history the authors assessed cumulative airborne occupational exposure for 10 agents, analysed individually and combined, by a deterministic additive model including probability, frequency, and intensity. Furthermore, occupations and industries of longest duration were analysed. Relative risks were estimated by odds ratios (OR), with 95% confidence intervals (CI), using conditional logistic regression, adjusted for potential confounders. Results Tendencies of positive associations were found between high exposure to pesticides and risk of oesophageal (OR 2.3 (95% CI 0.9 to 5.7)) and cardia adenocarcinoma (OR 2.1 (95% CI 1.0 to 4.6)). Among workers highly exposed to particular agents, a tendency of an increased risk of oesophageal squamous cell carcinoma was found. There was a twofold increased risk of oesophageal squamous cell carcinoma among concrete and construction workers (OR 2.2 (95% CI 1.1 to 4.2)) and a nearly fourfold increased risk of cardia adenocarcinoma among workers within the motor vehicle industry (OR 3.9 (95% CI 1.5 to 10.4)). An increased risk of oesophageal squamous cell carcinoma (OR 3.9 (95% CI 1.2 to 12.5)), and a tendency of an increased risk of cardia adenocarcinoma (OR 2.8 (95% CI 0.9 to 8.5)), were identified among hotel and restaurant workers. Conclusions Specific airborne occupational exposures do not seem to be of major importance in the aetiology of oesophageal or

  9. Exposure of hairdressing apprentices to airborne hazardous substances

    PubMed Central

    Mounier-Geyssant, Estelle; Oury, Véronique; Mouchot, Lory; Paris, Christophe; Zmirou-Navier, Denis

    2006-01-01

    Background Few studies have investigated exposure of hairdressing apprentices to airborne irritants. This study describes exposure levels of apprentices to chemical products used in hairdressing salons in relation with their activity. Methods Following a two stages study design, a group of 300 students completed a questionnaire on their work activities and environment. Among these, a group of 28 subjects volunteered to undergo personal exposure and workplace concentrations measurements over a work shift, during a cold and a hot season, with the agreement of the salon owners. Three chemical substances were studied (ammonia, hydrogen peroxide and persulfates) because they are respiratory tract irritants and because their concentrations could be quantified within a 5 to 8 hour shift period. Results Personal exposure values for H2O2and NH3 (averages [standard deviations] are 0.05 [0.04] and 0.90 [0.76] mg.m-3, respectively) were greater than workplace ambient air concentrations (corresponding values of 0.04 [0.03] and 0.68 [0.42] mg.m-3) for H2O2 and NH3, with no significant seasonal variation. By contrast, workplace concentrations of persulfates (0.019 [0.018] mg.m-3) were greater than personal exposure (0.016 [0.021] mg.m-3, a finding that is consistent with the fact that bleaching is more often undertaken by senior hairdressers. However, all exposure values were lower than the current TLV TWA values. This study also shows that over half of technical spaces where chemical substances used for dying, permanenting or bleaching are manipulated, have no ventilation system, and not even a door or a window opening outside. Conclusion The study hairdressing salons, on average, were small, the most probable reason why occupational hygiene measures such as appropriate ventilation were too seldom implemented. As a consequence, young apprentices and senior hairdressers experience substantial exposure to known airways irritants. PMID:16893447

  10. 30 CFR 56.5005 - Control of exposure to airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: (a) Respirators approved by NIOSH under 42 CFR part 84 which are applicable and suitable for the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne...

  11. CHARACTERIZING THE SOURCES OF HUMAN EXPOSURE TO MUTAGENIC AND CARCINOGENIC CHEMICALS IN AIRBORNE FINE PARTICLES

    EPA Science Inventory

    Personal and ambient exposures to airborne fine particles, polycyclic aromatic hydrocarbons (PAH), and genotoxic activity has been studied in populations in the US, Japan, China, and the Czech Republic. Personal exposure monitors used to collect fine particles were extracted f...

  12. Characterization of endotoxin and 3-hydroxy fatty acid levels in air and settled dust from commercial aircraft cabins.

    PubMed

    Hines, C J; Waters, M A; Larsson, L; Petersen, M R; Saraf, A; Milton, D K

    2003-06-01

    Endotoxin was measured in air and dust samples collected during four commercial aircraft flights. Samples were analyzed for endotoxin biological activity using the Limulus assay. 3-hydroxy fatty acids (3-OH FA) of carbon chain lengths C10:0-C18:0 were determined in dust by gas chromatography-ion trap tandem mass spectrometry. The geometric mean (geometric standard deviation) endotoxin air level was 1.5 EU/m3 (1.9, n = 28); however, significant differences were found by flight within aircraft type. Mean endotoxin levels were significantly higher in carpet dust than in seat dust (140 +/- 81 vs. 51 +/- 25 EU/mg dust, n = 32 each, P < 0.001). Airborne endotoxin levels were not significantly related to either carpet or seat dust endotoxin levels. Mean 3-OH FA levels were significantly higher in carpet dust than in seat dust for C10:2, C12:0, and C14:0 (P < 0.001 for each), while the mean level of C16:0 was significantly higher in seat dust than in carpet dust (P < 0.01). Carpet dust endotoxin was significantly, but moderately, correlated with 3-OH-C12:0 and 3-OH-C14:0 (Pearson r = 0.52 and 0.48, respectively), while correlation of seat dust endotoxin with individual 3-OH FAs depended on the test statistic used. Mean endotoxin potency was significantly higher for carpet dust than for seat dust (6.3 +/- 3.0 vs. 3.0 +/- 1.4 EU/pmol LPS, P < 0.0001). Mean endotoxin levels in the air and dust of commercial aircraft cabins were generally higher than mean levels reported in homes and office buildings. These results suggest that exposure route and dust source are important considerations when relating endotoxin exposure to specific health outcomes.

  13. Exposure level and distribution characteristics of airborne bacteria and fungi in Seoul metropolitan subway stations.

    PubMed

    Kim, Ki Youn; Kim, Yoon Shin; Kim, Daekeun; Kim, Hyeon Tae

    2011-01-01

    The exposure level and distribution characteristics of airborne bacteria and fungi were assessed in the workers' activity areas (station office, bedroom, ticket office and driver's seat) and passengers' activity areas (station precinct, inside the passenger carriage, and platform) of the Seoul metropolitan subway. Among investigated areas, the levels of airborne bacteria and fungi in the workers' bedroom and station precincts were relatively high. No significant difference was found in the concentration of airborne bacteria and fungi between the underground and above ground activity areas of the subway. The genera identified in all subway activity areas with a 5% or greater detection rate were Staphylococcus, Micrococcus, Bacillus and Corynebacterium for airborne bacteria and Penicillium, Cladosporium, Chrysosporium, Aspergillus for airborne fungi. Staphylococcus and Micrococcus comprised over 50% of the total airborne bacteria and Penicillium and Cladosporium comprised over 60% of the total airborne fungi, thus these four genera are the predominant genera in the subway station. PMID:21173524

  14. Occupational exposure to airborne contaminants during offshore oil drilling.

    PubMed

    Kirkhus, Niels E; Thomassen, Yngvar; Ulvestad, Bente; Woldbæk, Torill; Ellingsen, Dag G

    2015-07-01

    The aim was to study exposure to airborne contaminants in oil drillers during ordinary work. Personal samples were collected among 65 drill floor workers on four stationary and six moveable rigs in the Norwegian offshore sector. Air concentrations of drilling mud were determined based on measurements of the non-volatile mud components Ca and Fe. The median air concentration of mud was 140 μg m(-3). Median air concentrations of oil mist (180 μg m(-3)), oil vapour (14 mg m(-3)) and organic carbon (46 μg m(-3)) were also measured. All contaminants were detected in all work areas (drill floor, shaker area, mud pits, pump room, other areas). The highest air concentrations were measured in the shaker area, but the differences in air concentrations between working areas were moderate. Oil mist and oil vapour concentrations were statistically higher on moveable rigs than on stationary rigs, but after adjusting for differences in mud temperature the differences between rig types were no longer of statistical significance. Statistically significant positive associations were found between mud temperature and the concentrations of oil mist (Spearman's R = 0.46) and oil vapour (0.39), and between viscosity of base oil and oil mist concentrations. Use of pressure washers was associated with higher air concentrations of mud. A series of 18 parallel stationary samples showed a high and statistically significant association between concentrations of organic carbon and oil mist (r = 0.98). This study shows that workers are exposed to airborne non-volatilized mud components. Air concentrations of volatile mud components like oil mist and oil vapour were low, but were present in all the studied working areas.

  15. Occupational exposure to airborne contaminants during offshore oil drilling.

    PubMed

    Kirkhus, Niels E; Thomassen, Yngvar; Ulvestad, Bente; Woldbæk, Torill; Ellingsen, Dag G

    2015-07-01

    The aim was to study exposure to airborne contaminants in oil drillers during ordinary work. Personal samples were collected among 65 drill floor workers on four stationary and six moveable rigs in the Norwegian offshore sector. Air concentrations of drilling mud were determined based on measurements of the non-volatile mud components Ca and Fe. The median air concentration of mud was 140 μg m(-3). Median air concentrations of oil mist (180 μg m(-3)), oil vapour (14 mg m(-3)) and organic carbon (46 μg m(-3)) were also measured. All contaminants were detected in all work areas (drill floor, shaker area, mud pits, pump room, other areas). The highest air concentrations were measured in the shaker area, but the differences in air concentrations between working areas were moderate. Oil mist and oil vapour concentrations were statistically higher on moveable rigs than on stationary rigs, but after adjusting for differences in mud temperature the differences between rig types were no longer of statistical significance. Statistically significant positive associations were found between mud temperature and the concentrations of oil mist (Spearman's R = 0.46) and oil vapour (0.39), and between viscosity of base oil and oil mist concentrations. Use of pressure washers was associated with higher air concentrations of mud. A series of 18 parallel stationary samples showed a high and statistically significant association between concentrations of organic carbon and oil mist (r = 0.98). This study shows that workers are exposed to airborne non-volatilized mud components. Air concentrations of volatile mud components like oil mist and oil vapour were low, but were present in all the studied working areas. PMID:26020723

  16. Endotoxin deposits on the inner surfaces of closed-face cassettes during bioaerosol sampling: a field investigation at composting facilities.

    PubMed

    Duquenne, Philippe; Simon, Xavier; Demange, Valérie; Harper, Martin; Wild, Pascal

    2015-05-01

    A set of 270 bioaerosol samples was taken from 15 composting facilities using polystyrene closed-face filter cassettes (CFCs). The objective was to measure the quantity of endotoxin deposits on the inner surfaces of the cassettes (sometimes referred to as 'wall deposits'). The results show that endotoxins are deposited on the inner surfaces of the CFCs through sampling and/or handling of samples. The quantity of endotoxins measured on inner surfaces range between 0.05 (the limit of detection of the method) and 3100 endotoxin units per cassette. The deposits can represent a large and variable percentage of the endotoxins sampled. More than a third of the samples presented a percentage of inner surface deposits >40% of the total quantity of endotoxins collected (filter + inner surfaces). Omitting these inner surface deposits in the analytical process lead to measurement errors relative to sampling all particles entering the CFC sampler, corresponding to a developing consensus on matching the inhalable particulate sampling convention. The result would be underestimated exposures and could affect the decision as to whether or not a result is acceptable in comparison to airborne concentration limits defined in terms of the inhalability convention. The results of this study suggest including the endotoxins deposited on the inner surfaces of CFCs during analysis. Further researches are necessary to investigate endotoxin deposits on the inner cassette surfaces in other working sectors.

  17. Chronic Superantigen Exposure Induces Systemic Inflammation, Elevated Bloodstream Endotoxin, and Abnormal Glucose Tolerance in Rabbits: Possible Role in Diabetes

    PubMed Central

    Vu, Bao G.; Stach, Christopher S.; Kulhankova, Katarina; Salgado-Pabón, Wilmara; Klingelhutz, Aloysius J.

    2015-01-01

    ABSTRACT Excessive weight and obesity are associated with the development of diabetes mellitus type 2 (DMII) in humans. They also pose high risks of Staphylococcus aureus colonization and overt infections. S. aureus causes a wide range of severe illnesses in both healthy and immunocompromised individuals. Among S. aureus virulence factors, superantigens are essential for pathogenicity. In this study, we show that rabbits that are chronically exposed to S. aureus superantigen toxic shock syndrome toxin-1 (TSST-1) experience impaired glucose tolerance, systemic inflammation, and elevated endotoxin levels in the bloodstream, all of which are common findings in DMII. Additionally, such DMII-associated findings are also seen through effects of TSST-1 on isolated adipocytes. Collectively, our findings suggest that chronic exposure to S. aureus superantigens facilitates the development of DMII, which may lead to therapeutic targeting of S. aureus and its superantigens. PMID:25714716

  18. Endotoxin and β-1,3-d-Glucan in Concentrated Ambient Particles Induce Rapid Increase in Blood Pressure in Controlled Human Exposures.

    PubMed

    Zhong, Jia; Urch, Bruce; Speck, Mary; Coull, Brent A; Koutrakis, Petros; Thorne, Peter S; Scott, James; Liu, Ling; Brook, Robert D; Behbod, Behrooz; Gibson, Heike; Silverman, Frances; Mittleman, Murray A; Baccarelli, Andrea A; Gold, Diane R

    2015-09-01

    Short-term exposure to particulate matter (PM) is associated with increased blood pressure (BP) in epidemiological studies. Understanding the impact of specific PM components on BP is essential in developing effective risk-reduction strategies. We investigated the association between endotoxin and β-1,3-d-Glucan-two major biological PM components-and BP. We also examined whether vascular endothelial growth factor, a vasodilatory inflammatory marker, modified these associations. We conducted a single-blind, randomized, crossover trial of controlled human exposure to concentrated ambient particles with 50 healthy adults. Particle-associated-endotoxin and β-1,3-d-Glucan were sampled using polycarbonate-membrane-filters. Supine resting systolic BP and diastolic BP were measured pre-, 0.5-hour post-, and 20-hour postexposure. Urine vascular endothelial growth factor concentration was determined using enzyme-linked immunosorbant assay and creatinine-corrected. Exposures to endotoxin and β-1,3-d-Glucan for 130 minutes were associated with increases in BPs: at 0.5-hour postexposure, every doubling in endotoxin concentration was associated with 1.73 mm Hg higher systolic BP (95% confidence interval, 0.28, 3.18; P=0.02) and 2.07 mm Hg higher diastolic BP (95% confidence interval, 0.74, 3.39; P=0.003); every doubling in β-1,3-d-Glucan concentration was associated with 0.80 mm Hg higher systolic BP (95% confidence interval, -0.07, 1.67; P=0.07) and 0.88 mm Hg higher diastolic BP (95% confidence interval, 0.09, 1.66; P=0.03). Vascular endothelial growth factor rose after concentrated ambient particle endotoxin exposure and attenuated the association between endotoxin and 0.5-hour postexposure diastolic BP (Pinteraction=0.02). In healthy adults, short-term endotoxin and β-1,3-d-Glucan exposures were associated with increased BP. Our findings suggest that the biological PM components contribute to PM-related cardiovascular outcomes, and postexposure vascular endothelial

  19. Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation, Interim report, September 1984-December 1985

    SciTech Connect

    Suba, E.A.; Elin, R.J.

    1986-01-01

    The structure and function of the highly purified U.S. reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a /sup 60/Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain-repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.

  20. Correlation between airborne U exposure and U urinalysis results at Bear Creek Uranium.

    PubMed

    Chase, G R

    1989-02-01

    Inhalation exposure history and U urinalysis data collected at Union Pacific Resources Company's Bear Creek Uranium milling operation, located in the Powder River Basin area of Wyoming, were studied to determine if a correlation could be made between airborne U exposure and U urinalysis results. It was observed from these data that U urinalysis results correlate with airborne U exposure levels when averaged over a period of time. The urinary U excretion rate, empirically derived from these data, was 1.8 X 10(-1) micrograms U in urine d-1 per micrograms U inhaled d-1 for samples collected after 2.9 d of no exposure.

  1. beta-(1,3)-Glucan exposure assessment by passive airborne dust sampling and new sensitive immunoassays.

    PubMed

    Noss, Ilka; Wouters, Inge M; Bezemer, Gillina; Metwali, Nervana; Sander, Ingrid; Raulf-Heimsoth, Monika; Heederik, Dick J J; Thorne, Peter S; Doekes, Gert

    2010-02-01

    Associations between house dust-associated beta-(1,3)-glucan exposure and airway inflammatory reactions have been reported, while such exposures in early childhood have been suggested to protect against asthma and wheezing. Most epidemiological studies have used reservoir dust samples and an inhibition enzyme immunoassay (EIA) for beta-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne beta-(1,3)-glucans in low-exposure environments, like homes. Specificities of available anti-beta-(1,3)-glucan antibodies were defined by direct and inhibition experiments. Three suitable antibody combinations were selected for sandwich EIAs. beta-(1,3)-Glucans in passive airborne dust collected with an electrostatic dust fall collector (EDC) and floor dust from seven homes were measured with the three EIAs. Floor dust samples were additionally analyzed in the inhibition EIA. The sandwich EIAs were sensitive enough for airborne glucan measurement and showed different specificities for commercial glucans, while the beta-(1,3)-glucan levels in house dust samples correlated strongly. The feasibility of measuring glucans in airborne dust with the recently introduced EDC method was further investigated by selecting the most suitable of the three EIAs to measure and compare beta-(1,3)-glucan levels in the EDC and in floor and actively collected airborne dust samples of the previously performed EDC validation study. The EDC beta-(1,3)-glucan levels correlated moderately with beta-(1,3)-glucans in actively collected airborne dust and floor dust samples, while the glucan levels in the airborne dust and floor dust samples did not correlate. The combination of the newly developed beta-(1,3)-glucan sandwich EIA with EDC sampling now allows assessment in large-scale population studies of exposure to airborne beta-(1,3)-glucans in homes or other low-exposure environments.

  2. Endotoxin in fine (PM 2.5) and coarse (PM 2.5-10) particle mass of ambient aerosols. A temporo-spatial analysis

    NASA Astrophysics Data System (ADS)

    Heinrich, Joachim; Pitz, Mike; Bischof, Wolfgang; Krug, Norbert; Borm, Paul J. A.

    Objectives: We collected fine (PM 2.5) and coarse (PM 2.5-10) particulate matter fractions in two areas ˜80 km apart and measured soluble endotoxin concentrations in both particle fractions. Here we report on temporo-spatial variation of endotoxin content in the collected particles. Methods: Dichotomous Anderson samplers were used to collect 21 weekly samples of PM 2.5 and PM 2.5-10 in both towns from January to June 2002. Each Teflon filter was water extracted and endotoxin was measured by a chromogenic Limulus Amoebocyte Lysate method. Endotoxin concentrations were expressed per mg of fine or mg of coarse mass and per sampled air volume (m 3). Results: For both cities, the mean endotoxin content in PM 2.5 was 1.2 EU mg -1; however the endotoxin content in the coarse fraction was ˜10 times higher compared to the fine mass fractions. Although endotoxin content is highly variable over time, a good correlation was observed between the two town sites for both fine ( r=0.85) and coarse PM ( r=0.88). The fluctuations of weekly endotoxin means were high in both areas suggesting a strong temporal dependence on particle source and composition. The endotoxin content in particles collected during May and June were two to four times higher than concentrations measured during the winter and early spring weeks. Conclusions: Ambient airborne endotoxin concentrations were detected in coarse and fine particle fraction, but 10-fold higher in the coarse PM. The strong seasonality and the week to week fluctuation of endotoxin content in PM indicate different biologic PM properties which might affect results of time series studies on short-term effects as well as in vitro studies and human exposure studies.

  3. Endotoxin concentration in poultry houses for laying hens kept in cages or in alternative housing systems.

    PubMed

    Huneau-Salaün, A; Le Bouquin, S; Bex-Capelle, V; Huonnic, D; Balaine, L; Guillam, M-T; Squizani, F; Segala, C; Michel, V

    2011-10-01

    Endotoxins as components of organic dust may have adverse effects on the respiratory health of workers in poultry buildings. The move towards more welfare-friendly housing systems for layers may increase worker exposure to air contaminants due to the use of litter. The endotoxin concentrations in the inhalable fraction of airborne dust (below 100 µm) from cage and alternative system houses (on-floor, free range and aviaries) were compared under both experimental and commercial conditions. The endotoxin concentration was higher in experimental aviaries (median: 565 EU/m³, range: 362-1491 EU/m³) than in cage housing (98 EU/m³ (51-470)). In field conditions, the endotoxin concentration in the air of 13 alternative houses was higher (35 to 3156 EU/m³) than in cage system buildings (n = 8, 78-576 EU/m³). It was correlated to the respirable dust concentration (fraction below 5 µm) and to the temperature inside the hen house but no seasonal variation was observed. The present study emphasises that considerable worker exposure to endotoxins may occur in laying houses, especially in alternative systems. PMID:22029777

  4. Comparison of endotoxin and particle bounce in Marple cascade samplers with and without impaction grease.

    PubMed

    Kirychuk, Shelley P; Reynolds, Stephen J; Koehncke, Niels; Nakatsu, J; Mehaffy, John

    2009-01-01

    The health of persons engaged in agricultural activities are often related or associated with environmental exposures in their workplace. Accurately measuring, analyzing, and reporting these exposures is paramount to outcomes interpretation. This paper describes issues related to sampling air in poultry barns with a cascade impactor. Specifically, the authors describe how particle bounce can affect measurement outcomes and how the use of impaction grease can impact particle bounce and laboratory analyses such as endotoxin measurements. This project was designed to (1) study the effect of particle bounce in Marple cascade impactors that use polyvinyl chloride (PVC) filters; (2) to determine the effect of impaction grease on endotoxin assays when sampling poultry barn dust. A pilot study was undertaken utilizing six-stage Marple cascade impactors with PVC filters. Distortion of particulate size distributions and the effects of impaction grease on endotoxin analysis in samples of poultry dust distributed into a wind tunnel were studied. Although there was no significant difference in the overall dust concentration between utilizing impaction grease and not, there was a greater than 50% decrease in the mass median aerodynamic diameter (MMAD) values when impaction grease was not utilized. There was no difference in airborne endotoxin concentration or endotoxin MMAD between filters treated with impaction grease and those not treated. The results indicate that particle bounce should be a consideration when sampling poultry barn dust with Marple samplers containing PVC filters with no impaction grease. Careful consideration should be given to the utilization of impaction grease on PVC filters, which will undergo endotoxin analysis, as there is potential for interference, particularly if high or low levels of endotoxin are anticipated. PMID:19437284

  5. Increased Intestinal Permeability Correlates with Sigmoid Mucosa alpha-Synuclein Staining and Endotoxin Exposure Markers in Early Parkinson's Disease

    PubMed Central

    Forsyth, Christopher B.; Shannon, Kathleen M.; Kordower, Jeffrey H.; Voigt, Robin M.; Shaikh, Maliha; Jaglin, Jean A.; Estes, Jacob D.; Dodiya, Hemraj B.; Keshavarzian, Ali

    2011-01-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder of aging. The pathological hallmark of PD is neuronal inclusions termed Lewy bodies whose main component is alpha-synuclein protein. The finding of these Lewy bodies in the intestinal enteric nerves led to the hypothesis that the intestine might be an early site of PD disease in response to an environmental toxin or pathogen. One potential mechanism for environmental toxin(s) and proinflammatory luminal products to gain access to mucosal neuronal tissue and promote oxidative stress is compromised intestinal barrier integrity. However, the role of intestinal permeability in PD has never been tested. We hypothesized that PD subjects might exhibit increased intestinal permeability to proinflammatory bacterial products in the intestine. To test our hypothesis we evaluated intestinal permeability in subjects newly diagnosed with PD and compared their values to healthy subjects. In addition, we obtained intestinal biopsies from both groups and used immunohistochemistry to assess bacterial translocation, nitrotyrosine (oxidative stress), and alpha-synuclein. We also evaluated serum markers of endotoxin exposure including LPS binding protein (LBP). Our data show that our PD subjects exhibit significantly greater intestinal permeability (gut leakiness) than controls. In addition, this intestinal hyperpermeability significantly correlated with increased intestinal mucosa staining for E. coli bacteria, nitrotyrosine, and alpha-synuclein as well as serum LBP levels in PD subjects. These data represent not only the first demonstration of abnormal intestinal permeability in PD subjects but also the first correlation of increased intestinal permeability in PD with intestinal alpha–synuclein (the hallmark of PD), as well as staining for gram negative bacteria and tissue oxidative stress. Our study may thus shed new light on PD pathogenesis as well as provide a new method for earlier diagnosis of PD and

  6. Airborne asbestos exposures associated with work on asbestos fire sleeve materials.

    PubMed

    Blake, Charles L; Harbison, Stephen C; Johnson, Giffe T; Harbison, Raymond D

    2011-11-01

    Asbestos-containing fire sleeves have been used as a fire protection measure for aircraft fluid hoses. This investigation was conducted to determine the level of airborne asbestos fiber exposure experienced by mechanics who work with fire sleeve protected hoses. Duplicate testing was performed inside a small, enclosed workroom during the fabrication of hose assemblies. Personal air samples taken during this work showed detectable, but low airborne asbestos fiber exposures. Analysis of personal samples (n=9) using phrase contract microscopy (PCM) indicated task duration airborne fiber concentrations ranging from 0.017 to 0.063 fibers per milliliter (f/ml) for sampling durations of 167-198 min, and 0.022-0.14 f/ml for 30 min samples. Airborne chrysotile fibers were detected for four of these nine personal samples, and the resulting asbestos adjusted airborne fiber concentrations ranged from 0.014 to 0.025 f/ml. These results indicate that work with asbestos fire sleeve and fire sleeve protected hose assemblies, does not produce regulatory noncompliant levels of asbestos exposure for persons who handle, cut and fit these asbestos-containing materials.

  7. Airborne asbestos take-home exposures during handling of chrysotile-contaminated clothing following simulated full shift workplace exposures.

    PubMed

    Sahmel, Jennifer; Barlow, Christy A; Gaffney, Shannon; Avens, Heather J; Madl, Amy K; Henshaw, John; Unice, Ken; Galbraith, David; DeRose, Gretchen; Lee, Richard J; Van Orden, Drew; Sanchez, Matthew; Zock, Matthew; Paustenbach, Dennis J

    2016-01-01

    The potential for para-occupational, domestic, or take-home exposures from asbestos-contaminated work clothing has been acknowledged for decades, but historically has not been quantitatively well characterized. A simulation study was performed to measure airborne chrysotile concentrations associated with laundering of contaminated clothing worn during a full shift work day. Work clothing fitted onto mannequins was exposed for 6.5 h to an airborne concentration of 11.4 f/cc (PCME) of chrysotile asbestos, and was subsequently handled and shaken. Mean 5-min and 15-min concentrations during active clothes handling and shake-out were 3.2 f/cc and 2.9 f/cc, respectively (PCME). Mean airborne PCME concentrations decreased by 55% 15 min after clothes handling ceased, and by 85% after 30 min. PCM concentrations during clothes handling were 11-47% greater than PCME concentrations. Consistent with previously published data, daily mean 8-h TWA airborne concentrations for clothes-handling activity were approximately 1.0% of workplace concentrations. Similarly, weekly 40-h TWAs for clothes handling were approximately 0.20% of workplace concentrations. Estimated take-home cumulative exposure estimates for weekly clothes handling over 25-year working durations were below 1 f/cc-year for handling work clothes contaminated in an occupational environment with full shift airborne chrysotile concentrations of up to 9 f/cc (8-h TWA).

  8. Assessment of airborne exposure and dermal contact to acrylamide during chemical grouting operations. Final report

    SciTech Connect

    McHugh, J.M.

    1987-07-22

    Acrylamide exposure may occur by inhalation, ingestion and skin absorption; acrylamide is a neurotoxin and an irritant. The report details the results of field studies to assess airborne exposure and dermal contact to acrylamide during chemical grouting operations. Occupational exposures to acrylamide were characterized for sewer mainline, lateral line, and manhole maintenance operations. The objective of the study was to collect exposure data based on observations and measurements to be used as an integral part of a quantitative risk assessment by the U.S. Environmental Protection Agency's Office of Toxic Substances.

  9. Neuropsychological Motor Outcomes in Adults from Airborne Manganese Exposure

    EPA Science Inventory

    Background: The literature on manganese (Mn) is dominated by occupational exposures of adults exposed often to high levels without protection. Neuropsychological adverse health effects are similar to Parkinson’s Disease with psychomotor slowing, tremor, cognitive and mood ...

  10. Airborne acidity: estimates of exposure and human health effects.

    PubMed Central

    Lippmann, M

    1985-01-01

    Human health effects have resulted from the inhalation of ambient acidic aerosols, and there is suggestive evidence that current North American levels of exposure are producing excesses in respiratory morbidity. Annual mean mortality rates have been correlated with ambient aerosol concentration indices, with SO4(2-), FP, IP, and TSP having a descending order as predictive coefficients. These pollutant indices also contain H+ in descending mass ratios, and may all be surrogates for H+ as an active agent. Controlled exposure studies in humans and animals provide evidence that acidic aerosols produce greater changes in respiratory mechanical function and rates of particle clearance than other constituents of ambient particulate matter. The strong acid content of the ambient aerosol has not been measured in any of the population based pollutant effects studies in which it is a likely causal factor. The absence of direct measurement data on acidic aerosol in these studies, and their reliance on surrogate indices such as SO2 and SO4(2-), precludes firm conclusions about exposure-response relationships. High priority areas for further investigation include systematic investigation of the spatial and temporal distribution of population exposures; extension and refinement of population response studies in relation to acid aerosol exposures; responses of normal healthy and asthmatic human volunteers to mixtures of acidic aerosols and oxidant vapors under controlled conditions of exposure and exercise intensity; and progression of changes in lung epithelia during repetitive daily exposures of experimental animals to acidic aerosols, oxidants, and their mixtures, with concurrent measurements of particle clearance and respiratory function. PMID:4076095

  11. Occupational exposure to airborne lead in Brazilian police officers.

    PubMed

    Rocha, Ernesto Díaz; Sarkis, Jorge E Souza; Carvalho, Maria de Fátima H; Santos, Gerson Vechio Dos; Canesso, Claudemir

    2014-07-01

    Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors' group was 5.5 μg/dL ± 0.6. The mean BLL for the cadets' group before the training was 3.3 μg/dL ± 0.15 and after the training the main BLL was 18.2 μg/d L± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 μg/dL) after the three days indoor shooting season. In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons. PMID:24411572

  12. Occupational exposure to airborne lead in Brazilian police officers.

    PubMed

    Rocha, Ernesto Díaz; Sarkis, Jorge E Souza; Carvalho, Maria de Fátima H; Santos, Gerson Vechio Dos; Canesso, Claudemir

    2014-07-01

    Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors' group was 5.5 μg/dL ± 0.6. The mean BLL for the cadets' group before the training was 3.3 μg/dL ± 0.15 and after the training the main BLL was 18.2 μg/d L± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 μg/dL) after the three days indoor shooting season. In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons.

  13. Endotoxin Deactivation by Transient Acidification

    PubMed Central

    Ribeiro, Melina M.; Xu, Xiumin; Klein, Dagmar; Kenyon, Norma S; Ricordi, Camillo; Felipe, Maria Sueli S.; Pastori, Ricardo L.

    2015-01-01

    Recombinant proteins are an important tool for research and therapeutic applications. Therapeutic proteins have been delivered to several cell types and tissues and might be used to improve the outcome of the cell transplantation. Recombinant proteins are propagated in bacteria, which will contaminate them with the lypopolysacharide-endotoxin found in the outer bacterial membrane. Endotoxin could interfere with in vitro biological assays and is the major pathological factor, which must be removed or inactivated before in vivo administration. Here we describe a one-step protocol in which the endotoxin activity on recombinant proteins is remarkably reduced by transient exposure to acidic conditions. Maximum endotoxin deactivation occurs at acidic pH below their respective isoelectric point (pI). This method does not require additional protein purification or separation of the protein from the endotoxin fraction. The endotoxin level was measured both in vitro and in vivo. For in vitro assessment we have utilized Limulus Amebocyte Lysate method for in vivo the pyrogenic test. We have tested the above-mentioned method with 5 different recombinant proteins including a monoclonal antibody clone 5c8 against CD154 produced by hybridomas. More than 99% of endotoxin was deactivated in all of the proteins, the recovery of the protein after deactivation varied between maximum 72.9 and minimum 46.8%. The anti CD154 clone 5c8 activity remained unchanged as verified by the measurement of binding capability to activated lymphocytes. Furthermore, the effectiveness of this method was not significantly altered by urea, commonly used in protein purification. This procedure provides a simple and cost-efficient way to reduce the endotoxin activity in antibodies and recombinant proteins. PMID:20412635

  14. Cardiac Autonomic Effects of Acute Exposures to Airborne Particulates in Men and Women

    NASA Technical Reports Server (NTRS)

    Howarth, M. S.; Schlegel, T. T.; Knapp, C. F.; Patwardhan, A. R.; Jenkins, R. A.; Ilgner, R. H.; Evans, J. M.

    2007-01-01

    The aim of this research was to investigate cardiac autonomic changes associated with acute exposures to airborne particulates. Methods: High fidelity 12-lead ECG (CardioSoft, Houston, TX) was acquired from 19 (10 male / 9 female) non-smoking volunteers (age 33.6 +/- 6.6 yrs) during 10 minutes pre-exposure, exposure and post-exposure to environmental tobacco smoke (ETS), cooking oil fumes, wood smoke and sham (water vapor). To control exposure levels, noise, subject activity, and temperature, all studies were conducted inside an environmental chamber. Results: The short-term fractal scaling exponent (Alpha-1) and the ratio of low frequency to high frequency Heart Rate Variability (HRV) powers (LF/HF, a purported sympathetic index) were both higher in males (p<0.017 and p<0.05, respectively) whereas approximate entropy (ApEn) and HF/(LF+HF) (a purported parasympathetic index) were both lower in males (p<0.036, and p<0.044, respectively). Compared to pre-exposure (p<0.0002) and sham exposure (p<0.047), male heart rates were elevated during early ETS post-exposure. Our data suggest that, in addition to tonic HRV gender differences, cardiac responses to some acute airborne particulates are gender related.

  15. Cellulosic building insulation versus mineral wool, fiberglass or perlite: installer's exposure by inhalation of fibers, dust, endotoxin and fire-retardant additives.

    PubMed

    Breum, N O; Schneider, T; Jørgensen, O; Valdbjørn Rasmussen, T; Skibstrup Eriksen, S

    2003-11-01

    A task-specific exposure matrix was designed for workers installing building insulation materials. A priori, a matrix element was defined by type of task (installer or helper), type of work area (attic spaces or wall cavities) and type of insulation material (slabs from mineral wool, fiberglass or flax; loose-fill cellulosic material or perlite). In the laboratory a mock-up (full scale) of a one-family house was used for simulated installation of insulation materials (four replicates per matrix element). Personal exposure to dust and fibers was measured. The dust was analyzed for content of endotoxin and some trace elements (boron and aluminum) from fire-retardant or mold-resistant additives. Fibers were characterized as WHO fibers or non-WHO fibers. In support of the exposure matrix, the dustiness of all the materials was measured in a rotating drum tester. For installers in attic spaces, risk of exposure was low for inhalation of dust and WHO fibers from slab materials of mineral wool or fiberglass. Slab materials from flax may cause high risk of exposure to endotoxin. The risk of exposure by inhalation of dust from loose-fill materials was high for installers in attic spaces and for some of the materials risk of exposure was high for boron and aluminum. Exposure by inhalation of cellulosic WHO fibers was high but little is known about the health effects and a risk assessment is not possible. For the insulation of walls, the risk of installers' exposure by inhalation of dust and fibers was low for the slab materials, while a high risk was observed for loose-fill materials. The exposure to WHO fibers was positively correlated to the dust exposure. A dust level of 6.1 mg/m3 was shown to be useful as a proxy for screening exposure to WHO fibers in excess of 10(6) fibers/m3. In the rotating drum, slabs of insulation material from mineral wool or fiberglass were tested as not dusty. Cellulosic loose-fill materials were tested as very dusty, and perlite proved to be

  16. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... concentration shall be determined by phase contrast microscopy (PCM) using the OSHA Reference Method in OSHA's asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... limit. When PCM results indicate a potential exposure exceeding the 0.1 f/cc full-shift limit or the 1...

  17. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... concentration shall be determined by phase contrast microscopy (PCM) using the OSHA Reference Method in OSHA's asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... limit. When PCM results indicate a potential exposure exceeding the 0.1 f/cc full-shift limit or the 1...

  18. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... concentration shall be determined by phase contrast microscopy (PCM) using the OSHA Reference Method in OSHA's asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... limit. When PCM results indicate a potential exposure exceeding the 0.1 f/cc full-shift limit or the 1...

  19. Estimation of Chronic Personal Exposure to Airborne Polycyclic Aromatic Hydrocarbons

    PubMed Central

    Choi, Hyunok; Zdeb, Michael; Perera, Frederica; Spengler, John

    2015-01-01

    Background Polycyclic aromatic hydrocarbons (PAH) exposure from solid fuel burning represents an important public health issue for the majority of the global population. Yet, understanding of individual-level exposures remains limited. Objectives To develop regionally adaptable chronic personal exposure model to pro-carcinogenic PAH (c-PAH) for the population in Kraków, Poland. Methods We checked the assumption of spatial uniformity in eight c-PAH using the coefficients of divergence (COD), a marker of absolute concentration differences. Upon successful validation, we developed personal exposure models for eight pro-carcinogenic PAH by integrating individual-level data with area-level meteorological or pollutant data. We checked the resulting model for accuracy and precision against home outdoor monitoring data. Results During winter, COD of 0.1 for Kraków suggest overall spatial uniformity in the ambient concentration of the eight c-PAH. The three models that we developed were associated with index of agreement approximately equal to 0.9, root mean square error < 2.6 ng/m3, and 90th percentile of absolute difference ≤ 4 ng/m3 for the predicted and the observed concentrations for eight pro-carcinogenic PAH. Conclusions Inexpensive and logistically feasible information could be used to estimate chronic personal exposure to PAH profiles, in lieu of costly and labor-intensive personal air monitoring at wide scale. At the same time, thorough validation through direct personal monitoring and assumption checking are critical for successful model development. PMID:25965038

  20. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools.

    PubMed

    Burdett, Garry J; Dewberry, Kirsty; Staff, James

    2016-01-01

    The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml(-1)) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml(-1). Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated

  1. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools

    PubMed Central

    Burdett, Garry J.; Dewberry, Kirsty; Staff, James

    2016-01-01

    The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml−1) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml−1. Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated

  2. Exposure to airborne particulate matter in the subway system.

    PubMed

    Martins, Vânia; Moreno, Teresa; Minguillón, María Cruz; Amato, Fulvio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier

    2015-04-01

    The Barcelona subway system comprises eight subway lines, at different depths, with different tunnel dimensions, station designs and train frequencies. An extensive measurement campaign was performed in this subway system in order to characterise the airborne particulate matter (PM) measuring its concentration and investigating its variability, both inside trains and on platforms, in two different seasonal periods (warmer and colder), to better understand the main factors controlling it, and therefore the way to improve air quality. The majority of PM in the underground stations is generated within the subway system, due to abrasion and wear of rail tracks, wheels and braking pads caused during the motion of the trains. Substantial variation in average PM concentrations between underground stations was observed, which might be associated to different ventilation and air conditioning systems, characteristics/design of each station and variations in the train frequency. Average PM2.5 concentrations on the platforms in the subway operating hours ranged from 20 to 51 and from 41 to 91 μg m(-3) in the warmer and colder period, respectively, mainly related to the seasonal changes in the subway ventilation systems. The new subway lines with platform screen doors showed PM2.5 concentrations lower than those in the conventional system, which is probably attributable not only to the more advanced ventilation setup, but also to the lower train frequency and the design of the stations. PM concentrations inside the trains were generally lower than those on the platforms, which is attributable to the air conditioning systems operating inside the trains, which are equipped with air filters. This study allows the analysis and quantification of the impact of different ventilation settings on air quality, which provides an improvement on the knowledge for the general understanding and good management of air quality in the subway system.

  3. Exposure to airborne particulate matter in the subway system.

    PubMed

    Martins, Vânia; Moreno, Teresa; Minguillón, María Cruz; Amato, Fulvio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier

    2015-04-01

    The Barcelona subway system comprises eight subway lines, at different depths, with different tunnel dimensions, station designs and train frequencies. An extensive measurement campaign was performed in this subway system in order to characterise the airborne particulate matter (PM) measuring its concentration and investigating its variability, both inside trains and on platforms, in two different seasonal periods (warmer and colder), to better understand the main factors controlling it, and therefore the way to improve air quality. The majority of PM in the underground stations is generated within the subway system, due to abrasion and wear of rail tracks, wheels and braking pads caused during the motion of the trains. Substantial variation in average PM concentrations between underground stations was observed, which might be associated to different ventilation and air conditioning systems, characteristics/design of each station and variations in the train frequency. Average PM2.5 concentrations on the platforms in the subway operating hours ranged from 20 to 51 and from 41 to 91 μg m(-3) in the warmer and colder period, respectively, mainly related to the seasonal changes in the subway ventilation systems. The new subway lines with platform screen doors showed PM2.5 concentrations lower than those in the conventional system, which is probably attributable not only to the more advanced ventilation setup, but also to the lower train frequency and the design of the stations. PM concentrations inside the trains were generally lower than those on the platforms, which is attributable to the air conditioning systems operating inside the trains, which are equipped with air filters. This study allows the analysis and quantification of the impact of different ventilation settings on air quality, which provides an improvement on the knowledge for the general understanding and good management of air quality in the subway system. PMID:25616190

  4. Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles

    PubMed Central

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L.

    2016-01-01

    Abstract The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm–2) at cell‐free conditions following 2 h exposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm–2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:26935862

  5. Human health effects of exposure to airborne acid.

    PubMed

    Folinsbee, L J

    1989-02-01

    This paper summarizes and critiques a series of reports on the health effects of acid aerosol exposure, presented at the Symposium on the Health Effects of Acid Aerosols and compares these data to selected previous studies. The role of the two major defenses against acid aerosols, the conversion of acid to the ammonium salts by respiratory ammonia and buffering of acid by airway surface liquid are discussed in relation to airway acid burdens expected from typical inhalation exposures. The roles of particle size and hygroscopicity on airway deposition of aerosol are also included. The major health effects studied were the effects of acid aerosol on mucociliary clearance in healthy individuals and changes in lung function in asthmatics, an important sensitive subpopulation. The broad range of response in asthmatics suggests the need for further study.

  6. Real-world exposure of airborne particulate matter triggers oxidative stress in an animal model

    PubMed Central

    Wan, Guohui; Rajagopalan, Sanjay; Sun, Qinghua; Zhang, Kezhong

    2010-01-01

    Epidemiological studies have shown a strong link between air pollution and the increase of cardio-pulmonary mortality and morbidity. In particular, inhaled airborne particulate matter (PM) exposure is closely associated with the pathogenesis of air pollution-induced systemic diseases. In this study, we exposed C57BIV6 mice to environmentally relevant PM in fine and ultra fine ranges (diameter < 2.5 μm, PM2.5) using a “real-world” airborne PM exposure system. We investigated the pathophysiologic impact of PM2.5 exposure in the animal model and in cultured primary pulmonary macrophages. We demonstrated that PM2.5 exposure increased the production of reactive oxygen species (ROS) in blood vessels in vivo. Furthermore, in vitro PM2.5 exposure experiment suggested that PM2.5 could trigger oxidative stress response, reflected by an increased expression of the anti-oxidative stress enzymes superoxide dismutase-1 (SOD-1) and heme oxygenase-1(HO-1), in mouse primary macrophages. Together, the results obtained through our “real-world” PM exposure approach demonstrated the pathophysiologic effect of ambient PM2.5 exposure on triggering oxidative stress in the specialized organ and cell type of an animal model. Our results and approach will be informative for the research in air pollution-associated physiology and pathology. PMID:21383899

  7. Personal exposures to airborne metals in London taxi drivers and office workers in 1995 and 1996.

    PubMed

    Pfeifer, G D; Harrison, R M; Lynam, D R

    1999-09-01

    In 1995, a petroleum marketer introduced a diesel fuel additive in the UK containing Mn as MMT (methylcyclopentadienyl manganese tricarbonyl). A small study of personal exposures to airborne Mn in London was conducted before and after introduction of the additive to identify any major impact of the additive on exposures. In 1995, personal exposures to Mn were measured in two groups, taxi drivers and office workers (10 subjects per group) for two consecutive 7-day periods. A similar study was carried out in 1996 to determine if exposures had changed. Samples were also analyzed for Ca, Al, Mg and Pb. In 1996, exposures to aerosol mass as total suspended particulates (TSP) and PM2.5 were measured in addition to the metals. Manganese exposures in this cohort did not increase as a result of introduction of the additive. However, a significant source of Mn exposure was discovered during the conduct of these tests. The mean exposure to Mn was higher among the office workers in both years than that of the taxi drivers. This was due to the fact that approximately half of the office workers commuted via the underground railway system where airborne dust and metal concentrations are significantly elevated over those in the general environment. Similar results have been noted in other cities having underground rail systems. Exposure to Mn, Pb, Ca, and Mg were not significantly different between the 2 years. Taxi drivers had higher exposures than office workers to Mg and Pb in both years. Commuting via the underground also had a significant impact on exposures to TSP, PM2.5, Al, and Ca, but had little effect on exposures to Mg. The aerosol in the underground was particularly enriched in Mn, approximately 10-fold, when compared to the aerosol in the general environment. There are several possible sources for this Mn, including mechanical wear of the steel wheels on the steel rais, vaporization of metal from sparking of the third rail, or brake wear. PMID:10535124

  8. Safe human exposure limits for airborne linear siloxanes during spaceflight

    PubMed Central

    García, Hector D.; McMullin, Tami S.; Tobin, Joseph M.; James, John T.

    2013-01-01

    Background Low molecular weight siloxanes are used in industrial processes and consumer products, and their vapors have been detected in the atmospheres of the Space Shuttle and International Space Station. Therefore, the National Aeronautics and Space Administration (NASA) developed spacecraft maximum allowable concentrations (SMACs) for siloxane vapors to protect astronaut health. Since publication of these original SMACs, new studies and new risk assessment approaches have been published that warrant re-examination of the SMACs. Objective To reevaluate SMACs published for octamethyltrisiloxane (L3) for exposures ranging from 1 hour to 180 days, to develop a 1000-day SMAC, and to expand the applicability of those values to the family of linear siloxanes. Methods A literature review was conducted to identify studies conducted since the SMACs for L3 were set in 1994. The updated data were reviewed to determine the sensitive toxicity endpoints, and current risk assessment approaches and methods for dosimetric adjustments were evaluated. Results Recent data were used to update the original 1-hour, 24-hour, 30-day, and 180-day SMACs for L3, and a 1000-day SMAC was developed to protect crewmembers during future exploration beyond Earth orbit. Group SMACs for the linear siloxane family, including hexamethyldisiloxane (L2), L3, decamethyltetrasiloxane (L4), and dodecamethylpentasiloxane (L5), were set for exposures of 1-hour to 1000 days. Conclusion New SMACs, based on acute pulmonary and neurotoxicity at high doses only achievable with L2 and potential liver effects following longer-term exposures to L2 and L3, were established to protect crewmembers from the adverse effects of exposure to linear siloxanes. PMID:24255951

  9. Integrating Public Data Sets for Analysis of Maternal Airborne Environmental Exposures and Stillbirth

    PubMed Central

    Hall, Eric S.; Connolly, Natalia; Jones, David E.; DeFranco, Emily A.

    2014-01-01

    Efforts to study relationships between maternal airborne pollutant exposures and poor pregnancy outcomes have been frustrated by data limitations. Our objective was to report the proportion of Ohio women in 2006–2010 experiencing stillbirth whose pregnancy exposure to six criteria airborne pollutants could be approximated by applying a geospatial approach to vital records and Environmental Protection Agency air monitoring data. In addition, we characterized clinical and socio-demographic differences among women who lived within 10 km of monitoring stations compared to women who did not live within proximity of monitoring stations. For women who experienced stillbirth, 10.8% listed a residence within 10 km of each type of monitoring station. Maternal race, education, and marital status were significantly different (p<0.0001) comparing those within proximity to monitoring stations to those outside of monitoring range. No significant differences were identified in maternal age, ethnicity, smoking status, hypertension, or diabetes between groups. PMID:25954365

  10. Lipopolysaccharide Endotoxins

    PubMed Central

    Raetz, Christian R. H.; Whitfield, Chris

    2008-01-01

    Summary Since lipopolysaccharide endotoxins of Gram-negative bacteria were last reviewed in this series in 1990, much has been learned about the assembly and signaling functions of these remarkable glycoconjugates. Lipopolysaccharides typically consist of a hydrophobic domain known as lipid A (or endotoxin), a non-repeating “core” oligosaccharide, and a distal polysaccharide (or O-antigen). The flood of recent genomic data has made it possible to study lipopolysaccharide assembly in diverse Gram-negative bacteria, many of which are human or plant pathogens, and to create mutants or hybrid constructs with novel properties. Unexpectedly, key genes for lipid A biosynthesis have also been found in higher plants, indicating that eucaryotic lipid A-like molecules may exist. The carbohydrate diversity of lipopolysaccharides is better appreciated now than ten years ago, but much remains to be learned about function. Sequence comparisons suggest that extensive lateral transfer of genes for the assembly of O-antigens has occurred among bacteria. The most significant finding in the field of endotoxin biology since 1990 has been the identification of the plasma membrane protein TLR4 as the lipid A signaling receptor of animal cells. The latter belongs to a family of innate immunity receptors, all of which possess a large extracellular domain of leucine-rich repeats, a single trans-membrane segment and a smaller cytoplasmic signaling region that engages the adaptor protein MyD88. The expanding knowledge of TLR4 specificity and its downstream signaling pathways should provide new opportunities for blocking the inflammatory side effects of sepsis. Future progress will require insights into lipopolysaccharide-protein recognition at the atomic level, greater understanding of intra- and inter-cellular lipopolysaccharide trafficking, and incisive biological approaches that combine the tools of bacterial and animal genetics. PMID:12045108

  11. Occupational exposure to airborne asbestos from phenolic molding material (Bakelite) during sanding, drilling, and related activities.

    PubMed

    Mowat, Fionna; Bono, Michael; Lee, R J; Tamburello, Susan; Paustenbach, Dennis

    2005-10-01

    In this study, a historical phenolic (Bakelite) molding material, BMMA-5353, was tested to determine the airborne concentrations of asbestos fibers released during four different activities (sawing, sanding, drilling, and cleanup of dust generated from these activities). Each activity was performed for 30 min, often in triplicate. The primary objective for testing BMMA-5353 was to quantitatively determine the airborne concentration of asbestos fibers, if any, in the breathing zone of workers. Uses of this product typically did not include sawing or sanding, but it may have been drilled occasionally. For this reason, only small quantities were sawed, sanded, and drilled in this simulation study. Personal (n = 40), area (n = 80), and background/clearance (n = 88) air samples were collected during each activity and analyzed for total fiber concentrations using phase contrast microscopy (PCM) and, for asbestos fiber counts, transmission electron microscopy (TEM). The raw PCM-total fiber concentrations were adjusted based on TEM analyses that reported the fraction of asbestos fibers, to derive a PCM-asbestos concentration that would enable calculation of an 8-hour time-weighted average (TWA). The estimated 8-hour TWAs ranged from 0.006 to 0.08 fibers per cubic centimeter using a variety of worker exposure scenarios. Therefore, assuming an exposure scenario in which a worker uses power tools to cut and sand products molded from BMMA-5353 and similar products in the manner evaluated in this study, airborne asbestos concentrations should not exceed current or historical occupational exposure limits.

  12. Airborne exposures and risk of gastric cancer: a prospective cohort study.

    PubMed

    Sjödahl, Krister; Jansson, Catarina; Bergdahl, Ingvar A; Adami, Johanna; Boffetta, Paolo; Lagergren, Jesper

    2007-05-01

    There is an unexplained male predominance among patients with gastric cancer, and many carcinogens are found in male-dominated dusty occupations. However, the relation between occupational exposures and risk of gastric cancer remains unclear. To investigate whether airborne occupational exposures might influence the risk of noncardia gastric cancer, we used a large, prospective cohort study of male Swedish construction workers. These workers were, during the period 1971-1993, regularly invited to health examinations by a nationwide occupational health service organization. Data on job titles and other variables were collected through self-administered questionnaires and forms completed by the health organization's staff. Industrial hygienists assessed 12 specific airborne occupational exposures for 200 job titles. Gastric cancer, death or emigration occurring during follow-up in 1971-2002 were identified by linkage to the Swedish registers of Cancer, Causes of Death and Total Population, respectively. Incidence rate ratios (IRR) and 95% confidence intervals (CI), adjusted for attained age, tobacco smoking, calendar period and body mass, were derived from Cox regression. Among 256,357 cohort members, contributing 5,378,012 person-years at risk, 948 noncardia gastric cancers were identified. Increased risk of this tumor was found among workers exposed to cement dust (IRR 1.5 [95% CI 1.1-2.1]), quartz dust (IRR 1.3 [95% CI 1.0-1.7]) and diesel exhaust (IRR 1.4 [95% CI 1.1-1.9]). Dose-response relations were observed for these exposures. No consistent positive associations were found regarding exposure to asbestos, asphalt fumes, concrete dust, epoxy resins, isocyanates, metal fumes, mineral fibers, organic solvents or wood dust. In conclusion, this study provides some support to the hypothesis that specific airborne exposures increase the risk of noncardia gastric cancer. PMID:17266028

  13. Airborne exposures and risk of gastric cancer: a prospective cohort study.

    PubMed

    Sjödahl, Krister; Jansson, Catarina; Bergdahl, Ingvar A; Adami, Johanna; Boffetta, Paolo; Lagergren, Jesper

    2007-05-01

    There is an unexplained male predominance among patients with gastric cancer, and many carcinogens are found in male-dominated dusty occupations. However, the relation between occupational exposures and risk of gastric cancer remains unclear. To investigate whether airborne occupational exposures might influence the risk of noncardia gastric cancer, we used a large, prospective cohort study of male Swedish construction workers. These workers were, during the period 1971-1993, regularly invited to health examinations by a nationwide occupational health service organization. Data on job titles and other variables were collected through self-administered questionnaires and forms completed by the health organization's staff. Industrial hygienists assessed 12 specific airborne occupational exposures for 200 job titles. Gastric cancer, death or emigration occurring during follow-up in 1971-2002 were identified by linkage to the Swedish registers of Cancer, Causes of Death and Total Population, respectively. Incidence rate ratios (IRR) and 95% confidence intervals (CI), adjusted for attained age, tobacco smoking, calendar period and body mass, were derived from Cox regression. Among 256,357 cohort members, contributing 5,378,012 person-years at risk, 948 noncardia gastric cancers were identified. Increased risk of this tumor was found among workers exposed to cement dust (IRR 1.5 [95% CI 1.1-2.1]), quartz dust (IRR 1.3 [95% CI 1.0-1.7]) and diesel exhaust (IRR 1.4 [95% CI 1.1-1.9]). Dose-response relations were observed for these exposures. No consistent positive associations were found regarding exposure to asbestos, asphalt fumes, concrete dust, epoxy resins, isocyanates, metal fumes, mineral fibers, organic solvents or wood dust. In conclusion, this study provides some support to the hypothesis that specific airborne exposures increase the risk of noncardia gastric cancer.

  14. Endotoxins in urban air in Stockholm, Sweden

    NASA Astrophysics Data System (ADS)

    Nilsson, S.; Merritt, A. S.; Bellander, T.

    2011-01-01

    Endotoxins, i.e. components originating from the outer membrane in the cell wall of Gram-negative bacteria, activate the human immune system, which may result in airway symptoms such as shortness of breath and airway inflammation. Endotoxins are present in the environment, both outdoors and indoors, and stay airborne for a long time. In order to investigate the levels of endotoxins in urban air and the influence of traffic and meteorological factors, particles (PM 10 and PM 2.5) were collected at five sites in Stockholm, Sweden on four occasions per site between May and September 2009. Endotoxins were extracted from the filters and analysis was conducted with the Limulus Amebocyte Lysate (LAL)-assay. Endotoxins were present in urban air in Stockholm, albeit in low levels, and were similar to levels found in urban areas outside Sweden. To our knowledge, this is the northernmost location where endotoxins have been measured. The endotoxin levels found in PM 10 ranged from 0.020 to 0.107 EU m -3 with a geometric mean of 0.050 EU m -3 and the levels found in PM 2.5 ranged from 0.005 to 0.064 EU m -3 with a geometric mean of 0.015 EU m -3. No obvious effects of traffic or meteorological factors on endotoxin levels were observed, although a moderate correlation could be seen with soot. The small number of sampling sites is however a shortcoming of the present study. In future studies, more sites and sampling during all seasons would be preferable in order to get a better picture of the influence of different sources on endotoxin levels.

  15. [Occupational exposure to airborne fungi and bacteria in a household recycled container sorting plant ].

    PubMed

    Solans, Xavier; Alonso, Rosa María; Constans, Angelina; Mansilla, Alfonso

    2007-06-01

    Several studies have showed an association between the work in waste treatment plants and occupational health problems such as irritation of skin, eyes and mucous membranes, pulmonary diseases, gastrointestinal problems and symptoms of organic dust toxic syndrome (ODTS). These symptoms have been related to bioaerosol exposure. The aim of this study was to investigate the occupational exposure to biological agents in a plant sorting source-separated packages (plastics materials, ferric and non-ferric metals) household waste. Airborne samples were collected with M Air T Millipore sampler. The concentration of total fungi and bacteria and gram-negative bacteria were determined and the most abundant genera were identified. The results shown that the predominant airborne microorganisms were fungi, with counts greater than 12,000 cfu/m(3) and gram-negative bacteria, with a environmental concentration between 1,395 and 5,280 cfu/m(3). In both cases, these concentrations were higher than levels obtained outside of the sorting plant. Among the fungi, the predominant genera were Penicillium and Cladosporium, whereas the predominant genera of gram-negative bacteria were Escherichia, Enterobacter, Klebsiella and Serratia. The present study shows that the workers at sorting source-separated packages (plastics materials, ferric and non-ferric metals) domestic waste plant may be exposed to airborne biological agents, especially fungi and gram-negative bacteria.

  16. [Occupational exposure to airborne fungi and bacteria in a household recycled container sorting plant ].

    PubMed

    Solans, Xavier; Alonso, Rosa María; Constans, Angelina; Mansilla, Alfonso

    2007-06-01

    Several studies have showed an association between the work in waste treatment plants and occupational health problems such as irritation of skin, eyes and mucous membranes, pulmonary diseases, gastrointestinal problems and symptoms of organic dust toxic syndrome (ODTS). These symptoms have been related to bioaerosol exposure. The aim of this study was to investigate the occupational exposure to biological agents in a plant sorting source-separated packages (plastics materials, ferric and non-ferric metals) household waste. Airborne samples were collected with M Air T Millipore sampler. The concentration of total fungi and bacteria and gram-negative bacteria were determined and the most abundant genera were identified. The results shown that the predominant airborne microorganisms were fungi, with counts greater than 12,000 cfu/m(3) and gram-negative bacteria, with a environmental concentration between 1,395 and 5,280 cfu/m(3). In both cases, these concentrations were higher than levels obtained outside of the sorting plant. Among the fungi, the predominant genera were Penicillium and Cladosporium, whereas the predominant genera of gram-negative bacteria were Escherichia, Enterobacter, Klebsiella and Serratia. The present study shows that the workers at sorting source-separated packages (plastics materials, ferric and non-ferric metals) domestic waste plant may be exposed to airborne biological agents, especially fungi and gram-negative bacteria. PMID:17604432

  17. Exposure to airborne fungi and bacteria while commuting in passenger cars and public buses

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hyun; Jo, Wan-Kuen

    The present study examined airborne microbe levels inside and outside passenger cars and public buses during two seasons (winter and summer). The prevalence level of individual fungal genera depended on the fungi and agar type, whereas a constant higher prevalence (>90%) was found for the total bacteria and total fungi. The four most prevalent fungal genera were Cladosporium, Penicillium, Aspergillus, and Alternaria in a descending order. The major parameters associated with the airborne microbe measurements included agar type, vehicle type, and seasonal variation. When compared to the malt extract agar (MEA), the dichloran glycerol 18 agar (DG-18) was found to produce better counts for the target fungi. The summer in-vehicle bacterial concentrations were significantly higher for public buses than for the passenger cars, whereas the reverse was true for summer in-vehicle total fungal concentrations. This pattern was also consistent with summer outdoor results. In contrast, the winter in-vehicle and outdoor airborne microbe levels were similar for cars and buses. Meanwhile, summer was generally found to have higher in-vehicle fungal concentrations than winter. The current in-vehicle airborne microbe concentrations were found to be similar to residential indoor values from other reports, such as bacterial values between 10 and 10 3 CFU m -3 and total fungal aerosol concentrations ranging from 10 to 10 3 CFU m -3. It was suggested that motor vehicles in which many individuals spend a certain percentage of their day or week for travel are also a potential microenvironment for individual exposure to airborne microbes.

  18. Nephropathy in cadmium workers: assessment of risk from airborne occupational exposure to cadmium.

    PubMed Central

    Thun, M J; Osorio, A M; Schober, S; Hannon, W H; Lewis, B; Halperin, W

    1989-01-01

    To assess the quantitative relation between exposure to airborne cadmium and various markers of renal tubular and glomerular function, 45 male workers employed at a plant that recovers cadmium from industrial waste and 32 male hospital workers of similar age and geographical location were examined. Cumulative external exposure to airborne cadmium (dose) was estimated from historical air sampling data, adjusted for respirator use. Increasing cadmium dose was associated with multiple renal tubular functional abnormalities, including reduced reabsorption of beta-2-microglobulin (beta-2), retinol binding protein (RBP), calcium, and phosphate. Serum creatinine concentration also increased with cadmium dose, suggesting impaired glomerular function. Mean systolic and diastolic blood pressures were higher in the cadmium workers than in the unexposed (134 v 120 mm Hg and 80 v 73 mm Hg respectively), but only systolic blood pressure was significantly associated with cadmium dose in multivariate analyses. Cadmium dose remained the most important predictor of serum creatinine concentration after controlling for age, blood pressure, body size, and other extraneous factors. Logistic regression to model the probability (prevalence) of various renal abnormalities with increasing dose of cadmium was used. The probability of multiple tubular abnormalities and raised serum creatinine concentration increased sharply at cumulative cadmium exposures exceeding 300 mg/m3 days, corresponding to working for 4.3 years at the current permissible United States exposure limit for cadmium dust. PMID:2818957

  19. Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments - A review

    NASA Astrophysics Data System (ADS)

    Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Laitinen, Sirpa; Clifford, Sam; Mikkola, Raimo; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

    2016-10-01

    As endotoxin exposure has known effects on human health, it is important to know the generally existing levels of endotoxins as well as their contributing factors. This work reviews current knowledge on the endotoxin loads in settled floor dust, concentrations of endotoxins in indoor air, and different environmental factors potentially affecting endotoxin levels. The literature review consists of peer-reviewed manuscripts located using Google and PubMed, with search terms based on individual words and combinations. References from relevant articles have also been searched. Analysis of the data showed that in residential, school, and office environments, the mean endotoxin loads in settled floor dust varied between 660 and 107,000 EU/m2, 2180 and 48,000 EU/m2, and 2700 and 12,890 EU/m2, respectively. Correspondingly, the mean endotoxin concentrations in indoor air varied between 0.04 and 1610 EU/m3 in residences, and 0.07 and 9.30 EU/m3 in schools and offices. There is strong scientific evidence indicating that age of houses (or housing unit year category), cleaning, farm or rural living, flooring materials (the presence of carpets), number of occupants, the presence of dogs or cats indoors, and relative humidity affect endotoxin loads in settled floor dust. The presence of pets (especially dogs) was extremely strongly associated with endotoxin concentrations in indoor air. However, as reviewed articles show inconsistency, additional studies on these and other possible predicting factors are needed.

  20. The SLE Transcriptome Exhibits Evidence of Chronic Endotoxin Exposure and Has Widespread Dysregulation of Non-Coding and Coding RNAs

    PubMed Central

    Shi, Lihua; Zhang, Zhe; Yu, Angela M.; Wang, Wei; Wei, Zhi; Akhter, Ehtisham; Maurer, Kelly; Reis, Patrícia Costa; Song, Li; Petri, Michelle; Sullivan, Kathleen E.

    2014-01-01

    Background Gene expression studies of peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE) have demonstrated a type I interferon signature and increased expression of inflammatory cytokine genes. Studies of patients with Aicardi Goutières syndrome, commonly cited as a single gene model for SLE, have suggested that accumulation of non-coding RNAs may drive some of the pathologic gene expression, however, no RNA sequencing studies of SLE patients have been performed. This study was designed to define altered expression of coding and non-coding RNAs and to detect globally altered RNA processing in SLE. Methods Purified monocytes from eight healthy age/gender matched controls and nine SLE patients (with low-moderate disease activity and lack of biologic drug use or immune suppressive treatment) were studied using RNA-seq. Quantitative RT-PCR was used to validate findings. Serum levels of endotoxin were measured by ELISA. Results We found that SLE patients had diminished expression of most endogenous retroviruses and small nucleolar RNAs, but exhibited increased expression of pri-miRNAs. Splicing patterns and polyadenylation were significantly altered. In addition, SLE monocytes expressed novel transcripts, an effect that was replicated by LPS treatment of control monocytes. We further identified increased circulating endotoxin in SLE patients. Conclusions Monocytes from SLE patients exhibit globally dysregulated gene expression. The transcriptome is not simply altered by the transcriptional activation of a set of genes, but is qualitatively different in SLE. The identification of novel loci, inducible by LPS, suggests that chronic microbial translocation could contribute to the immunologic dysregulation in SLE, a new potential disease mechanism. PMID:24796678

  1. Airborne benzene exposures from cleaning metal surfaces with small volumes of petroleum solvents.

    PubMed

    Hollins, Dana M; Kerger, Brent D; Unice, Kenneth M; Knutsen, Jeffrey S; Madl, Amy K; Sahmel, Jennifer E; Paustenbach, Dennis J

    2013-06-01

    Airborne benzene concentrations were measured in a room with controlled air exchange during surface cleaning with two petroleum-based solvents (a paint thinner and an engine degreaser). The solvents were spiked with benzene to obtain target concentrations of 0.001, 0.01, and 0.1% by volume in the liquid. Personal samples on the worker and area samples up to 1.8m away were collected over 12 events (n=84 samples) designed to examine variation in exposure with solvent type, cleaning method (rag wipe or spatula scrape), surface area cleaned, air exchange rate, solvent volume applied, and distance from the cleaned surface. Average task breathing zone concentrations of benzene represented by 18-32 min time-weighted averages were 0.01 ppm, 0.05 ppm, and 0.27 ppm, when the solvents contained approximately 0.003, 0.008, and 0.07% benzene. Solvent benzene concentration, volume applied, and distance from the handling activities had the greatest effect on airborne concentrations. The studied solvent products containing 0.07% benzene (spiked) did not exceed the current OSHA permissible exposure limit of 1 ppm (averaged over 8h) or the ACGIH Threshold Limit Value of 0.5 ppm, in any of the tested short-term exposure scenarios. These data suggest that, under these solvent use scenarios, petroleum-based solvent products produced in the United States after 1978 likely did not produce airborne benzene concentrations above those measured if the concentration was less than 0.1% benzene. PMID:23088855

  2. Characterizing exposures to airborne metals and nanoparticle emissions in a refinery.

    PubMed

    Miller, Arthur; Drake, Pamela L; Hintz, Patrick; Habjan, Matt

    2010-07-01

    An air quality survey was conducted at a precious metals refinery in order to evaluate worker exposures to airborne metals and to provide detailed characterization of the aerosols. Two areas within the refinery were characterized: a furnace room and an electro-refining area. In line with standard survey practices, both personal and area air filter samples were collected on 37-mm filters and analyzed for metals by inductively coupled plasma-atomic emission spectroscopy. In addition to the standard sampling, measurements were conducted using other tools, designed to provide enhanced characterization of the workplace aerosols. The number concentration and number-weighted particle size distribution of airborne particles were measured with a fast mobility particle sizer (FMPS). Custom-designed software was used to correlate particle concentration data with spatial location data to generate contour maps of particle number concentrations in the work areas. Short-term samples were collected in areas of localized high concentrations and analyzed using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) to determine particle morphology and elemental chemistry. Analysis of filter samples indicated that all of the workers were exposed to levels of silver above the Occupational Safety and Health Administration permissible exposure limit of 0.01 mg m(-3) even though the localized ventilation was functioning. Measurements with the FMPS indicated that particle number concentrations near the furnace increased up to 1000-fold above the baseline during the pouring of molten metal. Spatial mapping revealed localized elevated particle concentrations near the furnaces and plumes of particles rising into the stairwells and traveling to the upper work areas. Results of TEM/EDS analyses confirmed the high number of nanoparticles measured by the FMPS and indicated the aerosols were rich in metals including silver, lead, antimony, selenium, and zinc. Results of

  3. Airborne benzene exposures from cleaning metal surfaces with small volumes of petroleum solvents.

    PubMed

    Hollins, Dana M; Kerger, Brent D; Unice, Kenneth M; Knutsen, Jeffrey S; Madl, Amy K; Sahmel, Jennifer E; Paustenbach, Dennis J

    2013-06-01

    Airborne benzene concentrations were measured in a room with controlled air exchange during surface cleaning with two petroleum-based solvents (a paint thinner and an engine degreaser). The solvents were spiked with benzene to obtain target concentrations of 0.001, 0.01, and 0.1% by volume in the liquid. Personal samples on the worker and area samples up to 1.8m away were collected over 12 events (n=84 samples) designed to examine variation in exposure with solvent type, cleaning method (rag wipe or spatula scrape), surface area cleaned, air exchange rate, solvent volume applied, and distance from the cleaned surface. Average task breathing zone concentrations of benzene represented by 18-32 min time-weighted averages were 0.01 ppm, 0.05 ppm, and 0.27 ppm, when the solvents contained approximately 0.003, 0.008, and 0.07% benzene. Solvent benzene concentration, volume applied, and distance from the handling activities had the greatest effect on airborne concentrations. The studied solvent products containing 0.07% benzene (spiked) did not exceed the current OSHA permissible exposure limit of 1 ppm (averaged over 8h) or the ACGIH Threshold Limit Value of 0.5 ppm, in any of the tested short-term exposure scenarios. These data suggest that, under these solvent use scenarios, petroleum-based solvent products produced in the United States after 1978 likely did not produce airborne benzene concentrations above those measured if the concentration was less than 0.1% benzene.

  4. Sensory and other neurogenic effects of exposures to airborne office dust

    NASA Astrophysics Data System (ADS)

    Mølhave, L.; Kjærgaard, S. K.; Attermann, J.

    This Danish Office Dust Experiment investigated the response of 24 healthy non-sensitive adult subjects to exposure to normal office dust in the air (7 μg m -3 clean air, 136 and 390 μg m -3 TSP). The dust had no major identifiable specific reactive components. The exposure duration was 5 1/4 h and was arranged in a climate chamber in controlled atmospheric conditions. Measurements were made acutely at exposure onset, subacutely at exposure end and next day (late). As secondary aims the time course and threshold of any observed effect of the exposures, and the characteristics of any hyperresponding subgroup were investigated. In a questionnaire with 36 questions the dust exposures caused increased acute, subacute and late perceptions of reduced air quality, acute and subacute increased odor intensity, acute eye irritation, acute and late heavy head, subacute feeling of perspiration, and subacute general irritation. Cough increased subacutely during exposures. In addition, a performance test showed effects of dust exposures which also affected "Mood Scale" ratings. No effect was seen on an addition test for distraction, and objective measurements of skin humidity. The overall conclusion of the study is that healthy subjects without hypersensitivity reactions seem to respond to airborne house dust. The responses are both subjective sensory reactions and other neurogenic effects even at exposure levels within the range found in normal buildings. Some of the effects appeared acutely and decreased through adaptation while others increased during prolonged exposure and remained for more than 17 h after the exposure ended. The findings may indicate for this type of dust a threshold level for the dose-response relationships below 140 μg m -3.

  5. Environmental Factors Affecting Asthma and Allergies: Predicting and Simulating Downwind Exposure to Airborne Pollen

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey; Estes, Sue; Sprigg, William A.; Nickovic, Slobodan; Huete, Alfredo; Solano, Ramon; Ratana, Piyachat; Jiang, Zhangyan; Flowers, Len; Zelicoff, Alan

    2009-01-01

    This slide presentation reviews the environmental factors that affect asthma and allergies and work to predict and simulate the downwind exposure to airborne pollen. Using a modification of Dust REgional Atmosphere Model (DREAM) that incorporates phenology (i.e. PREAM) the aim was to predict concentrations of pollen in time and space. The strategy for using the model to simulate downwind pollen dispersal, and evaluate the results. Using MODerate-resolution Imaging Spectroradiometer (MODIS), to get seasonal sampling of Juniper, the pollen chosen for the study, land cover on a near daily basis. The results of the model are reviewed.

  6. Factors Affecting Vegetable Growers’ Exposure to Fungal Bioaerosols and Airborne Dust

    PubMed Central

    Hansen, Vinni M.; Meyling, Nicolai Vitt; Winding, Anne; Eilenberg, Jørgen; Madsen, Anne Mette

    2012-01-01

    We have quantified vegetable growers’ exposure to fungal bioaerosol components including (1→3)-β-d-glucan (β-glucan), total fungal spores, and culturable fungal units. Furthermore, we have evaluated factors that might affect vegetable growers’ exposure to fungal bioaerosols and airborne dust. Investigated environments included greenhouses producing cucumbers and tomatoes, open fields producing cabbage, broccoli, and celery, and packing facilities. Measurements were performed at different times during the growth season and during execution of different work tasks. Bioaerosols were collected with personal and stationary filter samplers. Selected fungal species (Beauveria spp., Trichoderma spp., Penicillium olsonii, and Penicillium brevicompactum) were identified using different polymerase chain reaction-based methods and sequencing. We found that the factors (i) work task, (ii) crop, including growth stage of handled plant material, and (iii) open field versus greenhouse significantly affected the workers’ exposure to bioaerosols. Packing of vegetables and working in open fields caused significantly lower exposure to bioaerosols, e.g. mesophilic fungi and dust, than harvesting in greenhouses and clearing of senescent greenhouse plants. Also removing strings in cucumber greenhouses caused a lower exposure to bioaerosols than harvest of cucumbers while removal of old plants caused the highest exposure. In general, the exposure was higher in greenhouses than in open fields. The exposures to β-glucan during harvest and clearing of senescent greenhouse plants were very high (median values ranging between 50 and 1500 ng m−3) compared to exposures reported from other occupational environments. In conclusion, vegetable growers’ exposure to bioaerosols was related to the environment, in which they worked, the investigated work tasks, and the vegetable crop. PMID:22003240

  7. Relationship Between Birth Weight and Exposure to Airborne Fine Particulate Potassium and Titanium During Gestation

    PubMed Central

    Bell, Michelle L.; Belanger, Kathleen; Ebisu, Keita; Gent, Janneane F.; Leaderer, Brian P.

    2012-01-01

    Airborne particles are linked to numerous health impacts, including adverse pregnancy outcomes. Most studies of particles examined total mass, although the chemical structure of particles varies widely. We investigated whether mother’s exposure to potassium (K) and titanium (Ti) components of airborne fine particulate matter (PM2.5) during pregnancy was associated with birth weight or risk of low birth weight (<2500 gm) for term infants. The study population was 76,788 infants born in four counties in Connecticut and Massachusetts, US, for August 2000-February 2004. Both K and Ti were associated with birth weight. An interquartile range (IQR) increase K was associated with an 8.75% (95% confidence interval (CI): 1.24–16.8%) increase in risk of low birth weight. An IQR increase in Ti was associated with a 12.1% (95% CI: 3.55–21.4%) increase in risk of low birth weight, with an estimate of 6.41% (95% CI: −5.80–20.2%) for males and 16.4% (95% CI: 5.13–28.9%) for females. Results were robust to sensitivity analysis of first births only, but not adjustment by co-pollutants. Disentangling the effects of various chemical components is challenging because of the covariance among some components due to similar sources. Central effect estimates for infants of African-American mothers were higher than those of white mothers, although the confidence intervals overlapped. Our results indicate that exposure to airborne potassium and titanium during pregnancy is associated with lower birth weight. Associations may relate to chemical components of sources producing K and Ti. PMID:22705336

  8. Relationship between birth weight and exposure to airborne fine particulate potassium and titanium during gestation.

    PubMed

    Bell, Michelle L; Belanger, Kathleen; Ebisu, Keita; Gent, Janneane F; Leaderer, Brian P

    2012-08-01

    Airborne particles are linked to numerous health impacts, including adverse pregnancy outcomes. Most studies of particles examined total mass, although the chemical structure of particles varies widely. We investigated whether mother's exposure to potassium (K) and titanium (Ti) components of airborne fine particulate matter (PM(2.5)) during pregnancy was associated with birth weight or risk of low birth weight (<2500 g) for term infants. The study population was 76,788 infants born in four counties in Connecticut and Massachusetts, US, for August 2000-February 2004. Both K and Ti were associated with birth weight. An interquartile range (IQR) increase K was associated with an 8.75% (95% confidence interval (CI): 1.24-16.8%) increase in risk of low birth weight. An IQR increase in Ti was associated with a 12.1% (95% CI: 3.55-21.4%) increase in risk of low birth weight, with an estimate of 6.41% (95% CI: -5.80-20.2%) for males and 16.4% (95% CI: 5.13-28.9%) for females. Results were robust to sensitivity analysis of first births only, but not adjustment by co-pollutants. Disentangling the effects of various chemical components is challenging because of the covariance among some components due to similar sources. Central effect estimates for infants of African-American mothers were higher than those of white mothers, although the confidence intervals overlapped. Our results indicate that exposure to airborne potassium and titanium during pregnancy is associated with lower birth weight. Associations may relate to chemical components of sources producing K and Ti.

  9. Inventory of PCBs in Chicago and Opportunities for Reduction in Airborne Emissions and Human Exposure.

    PubMed

    Shanahan, Caitlin E; Spak, Scott N; Martinez, Andres; Hornbuckle, Keri C

    2015-12-01

    Urban areas are important regional sources of airborne polychlorinated biphenyls (PCBs) and population-scale airborne exposure, yet a comprehensive bottom-up source inventory of PCB emissions has never been quantified at urban scales in the United States. Here we report a comprehensive parcel level inventory of PCB stocks and emissions for Chicago, Illinois, developed with a transferable method from publicly available data. Chicago's legacy stocks hold 276 ± 147 tonnes ∑PCBs, with 0.2 tonnes added annually. Transformers and building sealants represent the largest legacy categories at 250 and 20 tonnes, respectively. From these stocks, annual emissions rates of 203 kg for ∑PCBs and 3 kg for PCB 11 explain observed concentrations in Chicago air. Sewage sludge drying contributes 25% to emissions, soils 31%, and transformers 21%. Known contaminated sites account for <1% of stocks and 17% of emissions to air. Paint is responsible for 0.00001% of stocks but up to 7% of ∑PCBs emissions. Stocks and emissions are highly concentrated and not correlated with population density or demographics at the neighborhood scale. Results suggest that strategies to further reduce exposure and ecosystem deposition must focus on the largest emissions sources rather than the most contaminated sites or the largest closed source legacy stocks.

  10. Risk assessment of exposure to waterborne and airborne radon-222 in Illinois. Final report

    SciTech Connect

    Hallenbeck, W.H.

    1987-12-01

    This study analyzed epidemiological and experimental animal studies in order to develop exposure-response relationships for radon-induced cancer. These relationships were used to estimate lifetime risks and annual excess cases based on the available waterborne and airborne data for Illinois. Exceedances of the USEPA action level of 4pCi/l occurred in 13% of 303 first-floor measurements and 43% of 1094 basement measurements. For waterborne radon, the highest lifetime risk of cancer mortality associated with an Illinois groundwater-based drinking water system was estimated to be 4 x 104. The number of excess cases of fatal cancer generated per year in Illinois was estimated to be about six. For airborne radon, a tentative value of 0.9 pCi/l (for first floors), derived from the limited existing data, was used to estimate the average lifetime lung-cancer mortality risk and the number of excess cases of fatal lung cancer generated per year. The average lifetime lung-cancer mortality risk was estimated to be 0.0048, and the annual number of excess cases of fatal lung cancer was estimated to be 784. Due to the nature of the underlying exposure-response relationships for radon-induced cancer, the values presented most likely represent upper-bound estimates.

  11. Modeling Human Exposure Levels to Airborne Volatile Organic Compounds by the Hebei Spirit Oil Spill

    PubMed Central

    Kim, Jong Ho; Kwak, Byoung Kyu; Ha, Mina; Cheong, Hae-Kwan

    2012-01-01

    Objectives The goal was to model and quantify the atmospheric concentrations of volatile organic compounds (VOCs) as the result of the Hebei Spirit oil spill, and to predict whether the exposure levels were abnormally high or not. Methods We developed a model for calculating the airborne concentration of VOCs that are produced in an oil spill accident. The model was applied to a practical situation, namely the Hebei Spirit oil spill. The accuracy of the model was verified by comparing the results with previous observation data. The concentrations were compared with the currently used air quality standards. Results Evaporation was found to be 10- to 1,000-fold higher than the emissions produced from a surrounding industrial complex. The modeled concentrations for benzene failed to meet current labor environmental standards, and the concentration of benzene, toluene, ortho- meta- para-xylene were higher than the values specified by air quality standards and guideline values on the ocean. The concentrations of total VOCs were much higher than indoor environmental criteria for the entire Taean area for a few days. Conclusions The extent of airborne exposure was clearly not the same as that for normal conditions. PMID:22468262

  12. Prenatal Airborne Polycyclic Aromatic Hydrocarbon Exposure and Child IQ at Age 5 Years

    PubMed Central

    Perera, Frederica P.; Li, Zhigang; Whyatt, Robin; Hoepner, Lori; Wang, Shuang; Camann, David; Rauh, Virginia

    2010-01-01

    OBJECTIVE This study evaluated the relationship between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) and child intelligence. METHODS Children of nonsmoking black or Dominican-American women residing in New York City were monitored from in utero to 5 years of age, with determination of prenatal PAH exposure through personal air monitoring for the mothers during pregnancy. At 5 years of age, intelligence was assessed for 249 children by using the Wechsler Preschool and Primary Scale of Intelligence-Revised. Multivariate linear regression models were used to estimate and to test the associations between prenatal PAH exposure and IQ. RESULTS After adjustment for maternal intelligence, quality of the home caretaking environment, environmental tobacco smoke exposure, and other potentially confounding factors, high PAH levels (above the median of 2.26 ng/m3) were inversely associated with full-scale IQ (P = .007) and verbal IQ (P = .003) scores. Children in the high-exposure group had full-scale and verbal IQ scores that were 4.31 and 4.67 points lower, respectively, than those of less-exposed children (≤2.26 ng/m3). The associations between logarithmically transformed, continuous, PAH levels and these IQ measures also were significant (full-scale IQ: β = −3.00; P = .009; verbal IQ: β = −3.53; P = .002). CONCLUSION These results provide evidence that environmental PAHs at levels encountered in New York City air can affect children’s IQ adversely. PMID:19620194

  13. Effects of ozone and endotoxin coexposure on rat airway epithelium: potentiation of toxicant-induced alterations.

    PubMed Central

    Wagner, J G; Hotchkiss, J A; Harkema, J R

    2001-01-01

    Tropospheric ozone is the major oxidizing component in photochemical smog and is one of the most pervasive problems to human health of the criteria air pollutants for which the National Ambient Air Quality Standards have been designated by the Clean Air Act. Although many adverse health effects of ozone exposure have been documented in both humans and laboratory animals, controversy surrounds the establishment and implementation of ozone standards set forth by the U.S. Environmental Protection Agency. Because people are commonly exposed to more than one air pollutant at a time, studies that examine coexposures to airborne materials may be more relevant for assessing their risks to human health. Airborne biogenic substances such as pollens, spores, and bacterial products are ubiquitous in the environment, and when inhaled can cause adverse respiratory symptoms. One such biogenic agent, bacterial endotoxin, is a potent stimulus of airway inflammation and is a ubiquitous airborne contaminant commonly found in domestic, agricultural, and industrial settings. Little is known about the interaction of exposures to biogenic substances and criteria air pollutants such as ozone. In the last few years we have performed a series of studies in rodents that examined the biologic responses of the respiratory epithelium after airway exposures to both endotoxin and ozone. When exposed to ozone (0.5 ppm 8 hr/day for 3 days), Fischer rats develop lesions in the nasal transitional epithelium, whereas intranasal instillation of endotoxin (20 microg) elicits epithelial lesions in the respiratory epithelium of the nose and conducting airways. Our studies were designed to examine how exposure to one toxicant may affect the airway epithelial lesions induced by the other toxicant. We investigated the potential role of acute inflammation in the enhancement of airway epithelial lesions after exposure of these two toxicants in neutrophil-sufficient and neutrophil-deficient rodents. A summary

  14. Effects of ozone and endotoxin coexposure on rat airway epithelium: potentiation of toxicant-induced alterations.

    PubMed

    Wagner, J G; Hotchkiss, J A; Harkema, J R

    2001-08-01

    Tropospheric ozone is the major oxidizing component in photochemical smog and is one of the most pervasive problems to human health of the criteria air pollutants for which the National Ambient Air Quality Standards have been designated by the Clean Air Act. Although many adverse health effects of ozone exposure have been documented in both humans and laboratory animals, controversy surrounds the establishment and implementation of ozone standards set forth by the U.S. Environmental Protection Agency. Because people are commonly exposed to more than one air pollutant at a time, studies that examine coexposures to airborne materials may be more relevant for assessing their risks to human health. Airborne biogenic substances such as pollens, spores, and bacterial products are ubiquitous in the environment, and when inhaled can cause adverse respiratory symptoms. One such biogenic agent, bacterial endotoxin, is a potent stimulus of airway inflammation and is a ubiquitous airborne contaminant commonly found in domestic, agricultural, and industrial settings. Little is known about the interaction of exposures to biogenic substances and criteria air pollutants such as ozone. In the last few years we have performed a series of studies in rodents that examined the biologic responses of the respiratory epithelium after airway exposures to both endotoxin and ozone. When exposed to ozone (0.5 ppm 8 hr/day for 3 days), Fischer rats develop lesions in the nasal transitional epithelium, whereas intranasal instillation of endotoxin (20 microg) elicits epithelial lesions in the respiratory epithelium of the nose and conducting airways. Our studies were designed to examine how exposure to one toxicant may affect the airway epithelial lesions induced by the other toxicant. We investigated the potential role of acute inflammation in the enhancement of airway epithelial lesions after exposure of these two toxicants in neutrophil-sufficient and neutrophil-deficient rodents. A summary

  15. Analysing the health effects of simultaneous exposure to physical and chemical properties of airborne particles

    PubMed Central

    Pirani, Monica; Best, Nicky; Blangiardo, Marta; Liverani, Silvia; Atkinson, Richard W.; Fuller, Gary W.

    2015-01-01

    Background Airborne particles are a complex mix of organic and inorganic compounds, with a range of physical and chemical properties. Estimation of how simultaneous exposure to air particles affects the risk of adverse health response represents a challenge for scientific research and air quality management. In this paper, we present a Bayesian approach that can tackle this problem within the framework of time series analysis. Methods We used Dirichlet process mixture models to cluster time points with similar multipollutant and response profiles, while adjusting for seasonal cycles, trends and temporal components. Inference was carried out via Markov Chain Monte Carlo methods. We illustrated our approach using daily data of a range of particle metrics and respiratory mortality for London (UK) 2002–2005. To better quantify the average health impact of these particles, we measured the same set of metrics in 2012, and we computed and compared the posterior predictive distributions of mortality under the exposure scenario in 2012 vs 2005. Results The model resulted in a partition of the days into three clusters. We found a relative risk of 1.02 (95% credible intervals (CI): 1.00, 1.04) for respiratory mortality associated with days characterised by high posterior estimates of non-primary particles, especially nitrate and sulphate. We found a consistent reduction in the airborne particles in 2012 vs 2005 and the analysis of the posterior predictive distributions of respiratory mortality suggested an average annual decrease of − 3.5% (95% CI: − 0.12%, − 5.74%). Conclusions We proposed an effective approach that enabled the better understanding of hidden structures in multipollutant health effects within time series analysis. It allowed the identification of exposure metrics associated with respiratory mortality and provided a tool to assess the changes in health effects from various policies to control the ambient particle matter mixtures. PMID:25795926

  16. An analysis of historical exposures of pressmen to airborne benzene (1938-2006).

    PubMed

    Novick, Rachel M; Keenan, James J; Gross, Sherilyn A; Paustenbach, Dennis J

    2013-07-01

    Benzene is an aromatic hydrocarbon that, with sufficient cumulative lifetime doses, can cause acute myelogenous leukemia. Because of its volatility and solvent properties, it was used in the printing industry in inks, ink solvents, and cleaning agents from the 1930s to the 1970s. This analysis represents the first known attempt to gather and synthesize the available data on historical airborne benzene concentrations in printing facilities and exposures to pressmen. The sources of fugitive benzene vapors from printing operations have been identified as evaporation from ink fountains, exposed sections of the printing cylinder, the paper web, the paper post exit, and spilled ink. In addition, specific activities that could lead to benzene exposure, such as filling the fountains, using solvents to clean the press, and using solvents as personal cleaning agents, potentially occurred multiple times per work period. Eighteen studies were identified that reported workplace airborne concentrations in printing facilities between 1938 and 2006. Typical benzene air concentrations, considering both personal and area samples of various durations, were as high as 200 p.p.m. in the 1930s through the 1950s, 3-35 p.p.m. in the 1960s, 1.3-16 p.p.m. in the 1970s, 0.013-1 in the 1980s, and far less than 1 p.p.m. in the 1990s and 2000s. The decrease in benzene air concentrations by the late 1970s was likely to be linked to the decreased benzene content of printing materials, increased engineering controls, and to more stringent occupational exposure limits.

  17. Exposure to airborne methacrylates and natural rubber latex allergens in dental clinics.

    PubMed

    Henriks-Eckerman, M L; Alanko, K; Jolanki, R; Kerosuo, H; Kanerva, L

    2001-06-01

    The exposure of dental personnel to airborne methacrylates and natural rubber latex (NRL) allergens was studied during placing of composite resin restorations in six dental clinics in Finland. Both area and personal sampling were performed, and special attention was paid to measurement of short-term emissions from the patient's mouth. Methacrylates were collected onto thermal desorption tubes filled with Tenax TA and NRL allergens onto membrane filters. The methacrylate samples were thermally desorbed and analysed by gas chromatography with mass selective detection. The NRL allergen concentrations were determined by the allergen-specific IgE-ELISA-inhibition method. The median concentration of 2-hydroxyethylmethacrylate (2-HEMA) was 0.004 mg m-3 close to the dental nurse's work-desk and 0.003 mg m-3 in the breathing zone of the nurse with a maximum concentration of 0.033 mg m-3. Above the patient's mouth the concentration of 2-HEMA was about 0.01 mg m-3 during both working stages, i.e., during application of adhesive and composite resins and during finishing and polishing of the fillings. Maximum concentrations of 3-5 times higher than median concentrations were also measured. Triethyleneglycol dimethacrylate was released into the air mainly during the removal of old composite resin restorations (0.05 mg m-3) and only to a minor extent during finishing and polishing procedures. The median concentration of the NRL allergen was 0.12 au m-3 (au = arbitrary unit) with a maximum concentration of 1.1 au m-3. The results show that, except for short-term emissions from the patient's mouth, the exposure of dental personnel to methacrylates and NRL allergens is very low. Measures to reduce exposure are discussed, as the airborne concentrations of methacrylates should be kept as low as possible in order to reduce the risk of hypersensitivity.

  18. Spatial Patterns of Airborne Exposures of Tungsten and Cobalt in Fallon, Nevada, From Lichens and Surface Sediments

    NASA Astrophysics Data System (ADS)

    Sheppard, P. R.; Speakman, R. J.; Ridenour, G.; Glascock, M. D.; Farris, C.; Witten, M. L.

    2005-12-01

    This paper describes spatial patterns of airborne exposures of heavy metals in Fallon, Nevada, where a cluster of childhood leukemia has been on-going since 1997. Lichen chemistry, the measurement and interpretation of element concentrations in lichens, and surface sediment chemistry were used. Lichens were collected from within as well as from well outside of Fallon. Surface sediments were collected in a gridded spatial pattern, also within and outside of Fallon. Both the lichen and the surface sediment samples were measured chemically for a large suite of metals and other elements. Lichens indicate that Fallon itself has a high dual airborne exposure of tungsten and cobalt relative to sites well away from the town. Surface sediments samples also show high peaks of tungsten and cobalt within Fallon with nothing more than background contents away from the town. The tungsten and cobalt peaks coincide spatially with one another, with the highest values located right at a "hard-metal" facility that processes these metals. This present research confirms earlier research on total suspended particulates showing that Fallon is distinct in Nevada for its high dual exposure of airborne tungsten and cobalt and that the source of these two metals can be pinpointed to the hard-metal industry that exists just north of Highway 50 and west of Highway 95. While it is still not possible to conclude that high airborne exposure of tungsten and/or cobalt causes childhood leukemia, it can now be concluded beyond reasonable doubt that Fallon is unique environmentally due to its high airborne concentrations of tungsten and cobalt. Given that Fallon's cluster of childhood leukemia is the "most convincing cluster ever reported," it stands to reason that additional biomedical research should directly test the leukogenecity of combined airborne exposures of tungsten and cobalt.

  19. Exposure to airborne metals and particulate matter and risk for youth adjudicated for criminal activity

    SciTech Connect

    Haynes, Erin N.; Chen, Aimin; Ryan, Patrick; Succop, Paul; Wright, John; Dietrich, Kim N.

    2011-11-15

    Antisocial behavior is a product of multiple interacting sociohereditary variables, yet there is increasing evidence that metal exposure, particularly, manganese and lead, play a role in its epigenesis. Other metals, such as arsenic, cadmium, chromium, and mercury, and exposure to traffic-related air pollution, such as fine particulate matter ({<=}2.5 {mu}m) have been associated with neurological deficits, yet largely unexplored with respect to their relationship with delinquent behavior. The purpose of this study is to evaluate the ecological relationship between county-wide reported airborne emissions of air metals, particulate matter, and youth adjudicated for criminal activity. Metal exposure data were collected from the Environmental Protection Agency AirData. Population statistics were obtained from the United States Census 2000 and adjudication data was obtained from the Courts of Common Pleases from each Ohio County. Simple correlations were calculated with the percentage of adjudications, all covariates, and estimated metal air emissions. Separate negative binomial regression models for each pollutant were used to provide an estimated risk ratio of pollutant emissions on the risk of adjudication for all Ohio counties adjusting for urban-rural residence, percentage of African Americans, median family income, percentage of family below poverty, percentage of high school graduation in 25 years and older populations, and population density. Metal emissions and PM in 1999 were all correlated with adjudication rate (2003-2005 average). Metal emissions were associated with slightly higher risk of adjudication, with about 3-4% increased risk per natural log unit of metal emission except chromium. The associations achieved statistical significance for manganese and mercury. The particulate matter {<=}2.5 and {<=}10 {mu}m emissions had a higher risk estimate, with 12% and 19% increase per natural log unit emission, respectively, and also achieved statistical

  20. Human exposure to airborne aniline and formation of methemoglobin: a contribution to occupational exposure limits.

    PubMed

    Käfferlein, Heiko Udo; Broding, Horst Christoph; Bünger, Jürgen; Jettkant, Birger; Koslitz, Stephan; Lehnert, Martin; Marek, Eike Maximilian; Blaszkewicz, Meinolf; Monsé, Christian; Weiss, Tobias; Brüning, Thomas

    2014-07-01

    Aniline is an important starting material in the manufacture of polyurethane-based plastic materials. Aniline-derived methemoglobinemia (Met-Hb) is well described in exposed workers although information on the dose-response association is limited. We used an experimental design to study the association between aniline in air with the formation of Met-Hb in blood and the elimination of aniline in urine. A 6-h exposure of 2 ppm aniline in 19 non-smoking volunteers resulted in a time-dependent increase in Met-Hb in blood and aniline in urine. The maximum Met-Hb level in blood (mean 1.21 ± 0.29 %, range 0.80-2.07 %) and aniline excretion in urine (mean 168.0 ± 51.8 µg/L, range 79.5-418.3 µg/L) were observed at the end of exposure, with both parameters rapidly decreasing after the end of exposure. After 24 h, the mean level of Met-Hb (0.65 ± 0.18 %) returned to the basal level observed prior to the exposure (0.72 ± 0.19 %); whereas, slightly elevated levels of aniline were still present in urine (means 17.0 ± 17.1 vs. 5.7 ± 3.8 µg/L). No differences between males and females as well as between slow and fast acetylators were found. The results obtained after 6-h exposure were also comparable to those observed in four non-smoking volunteers after 8-h exposure. Maximum levels of Met-Hb and aniline in urine were 1.57 % and 305.6 µg/L, respectively. Overall, our results contribute to the risk assessment of aniline and as a result, the protection of workers from aniline-derived adverse health effects at the workplace.

  1. Human exposure to airborne aniline and formation of methemoglobin: a contribution to occupational exposure limits.

    PubMed

    Käfferlein, Heiko Udo; Broding, Horst Christoph; Bünger, Jürgen; Jettkant, Birger; Koslitz, Stephan; Lehnert, Martin; Marek, Eike Maximilian; Blaszkewicz, Meinolf; Monsé, Christian; Weiss, Tobias; Brüning, Thomas

    2014-07-01

    Aniline is an important starting material in the manufacture of polyurethane-based plastic materials. Aniline-derived methemoglobinemia (Met-Hb) is well described in exposed workers although information on the dose-response association is limited. We used an experimental design to study the association between aniline in air with the formation of Met-Hb in blood and the elimination of aniline in urine. A 6-h exposure of 2 ppm aniline in 19 non-smoking volunteers resulted in a time-dependent increase in Met-Hb in blood and aniline in urine. The maximum Met-Hb level in blood (mean 1.21 ± 0.29 %, range 0.80-2.07 %) and aniline excretion in urine (mean 168.0 ± 51.8 µg/L, range 79.5-418.3 µg/L) were observed at the end of exposure, with both parameters rapidly decreasing after the end of exposure. After 24 h, the mean level of Met-Hb (0.65 ± 0.18 %) returned to the basal level observed prior to the exposure (0.72 ± 0.19 %); whereas, slightly elevated levels of aniline were still present in urine (means 17.0 ± 17.1 vs. 5.7 ± 3.8 µg/L). No differences between males and females as well as between slow and fast acetylators were found. The results obtained after 6-h exposure were also comparable to those observed in four non-smoking volunteers after 8-h exposure. Maximum levels of Met-Hb and aniline in urine were 1.57 % and 305.6 µg/L, respectively. Overall, our results contribute to the risk assessment of aniline and as a result, the protection of workers from aniline-derived adverse health effects at the workplace. PMID:24899222

  2. Past occupational exposure to airborne manganese in a manganese alloy plant.

    PubMed

    Baldwin, Mary; Bouchard, Maryse; Larribe, Fabrice; Mergler, Donna

    2008-07-01

    A retrospective exposure assessment of a group of manganese (Mn) alloy workers was performed in conjunction with a 2004 follow-up study, 14 years after cessation of exposure, to evaluate the long-term effects of occupational Mn exposure on neurobehavioral functions. The ferro- and silico-Mn alloy plant opened in 1973 and closed in 1991. The airborne total Mn (TMn) exposures for job groupings were established using personal sampling data from a 1991 industrial hygiene survey. Historical short-term total dust (TDust) data were used to estimate past TDust exposure for job groupings and plant areas. Relationships between Mn content and TDust from the 1991 survey, supported by sparse historical data, were used to estimate TMn content in the historical TDust data. Results showed past personal TDust exposure levels much higher than those found in 1991. Changes in TDust levels and corresponding TMn levels were a function of changes in ventilation, work practices, and operations, not of product (ferro- or silico-Mn). Relationships between TMn and respirable Mn (RMn) from area sampling in 1991 were used to estimate RMn exposure for the job groups. Work histories for 112 workers were developed from payroll records, questionnaires, and interviews and combined with Mn exposure estimates to develop cumulative exposure indices (CEIs). The TMn CEI ranged from 0.27 mg/m(3)x years to 100.24 mg/m(3)x years, with an AM of 24.40 mg/m(3)x years and a GM of 14.06 mg/m(3)x years. The RMn CEI had an AM of 2.95 mg/m(3)x years and a GM of 1.78 mg/m(3)x years with a range of 0.05-12.03 mg/m(3)x years. Overall average TMn exposure intensity, the TMn CEI divided by time worked in years for each worker, had an AM of 1.6 mg Mn/m(3), a GM of 1.0 mg Mn/m(3), range 0.02-6.2 6 mg Mn/m(3). The results of the 2004 follow-up study showed several concentration-response relationships between TMn CEI and neurobehavioral outcomes, which suggest that increase in cumulative TMn exposure level has long

  3. Past occupational exposure to airborne manganese in a manganese alloy plant.

    PubMed

    Baldwin, Mary; Bouchard, Maryse; Larribe, Fabrice; Mergler, Donna

    2008-07-01

    A retrospective exposure assessment of a group of manganese (Mn) alloy workers was performed in conjunction with a 2004 follow-up study, 14 years after cessation of exposure, to evaluate the long-term effects of occupational Mn exposure on neurobehavioral functions. The ferro- and silico-Mn alloy plant opened in 1973 and closed in 1991. The airborne total Mn (TMn) exposures for job groupings were established using personal sampling data from a 1991 industrial hygiene survey. Historical short-term total dust (TDust) data were used to estimate past TDust exposure for job groupings and plant areas. Relationships between Mn content and TDust from the 1991 survey, supported by sparse historical data, were used to estimate TMn content in the historical TDust data. Results showed past personal TDust exposure levels much higher than those found in 1991. Changes in TDust levels and corresponding TMn levels were a function of changes in ventilation, work practices, and operations, not of product (ferro- or silico-Mn). Relationships between TMn and respirable Mn (RMn) from area sampling in 1991 were used to estimate RMn exposure for the job groups. Work histories for 112 workers were developed from payroll records, questionnaires, and interviews and combined with Mn exposure estimates to develop cumulative exposure indices (CEIs). The TMn CEI ranged from 0.27 mg/m(3)x years to 100.24 mg/m(3)x years, with an AM of 24.40 mg/m(3)x years and a GM of 14.06 mg/m(3)x years. The RMn CEI had an AM of 2.95 mg/m(3)x years and a GM of 1.78 mg/m(3)x years with a range of 0.05-12.03 mg/m(3)x years. Overall average TMn exposure intensity, the TMn CEI divided by time worked in years for each worker, had an AM of 1.6 mg Mn/m(3), a GM of 1.0 mg Mn/m(3), range 0.02-6.2 6 mg Mn/m(3). The results of the 2004 follow-up study showed several concentration-response relationships between TMn CEI and neurobehavioral outcomes, which suggest that increase in cumulative TMn exposure level has long

  4. Saran-Chloropel plastic suit worker dose rates from airborne tritium exposure - first exposure hour

    SciTech Connect

    Edwards, T.

    1993-04-20

    Radiological Engineering was requested to develop Tritium Stay Time Chart dose rates for the 9 mil Saran-Chloropel (CPE) plastic suit for a period of one hour or less. Assumptions utilized in previous calculations were revised to better address the first hour of exposure in the suit for emergency situations.

  5. Community exposures to airborne agricultural pesticides in California: ranking of inhalation risks.

    PubMed

    Lee, Sharon; McLaughlin, Robert; Harnly, Martha; Gunier, Robert; Kreutzer, Richard

    2002-12-01

    We assessed inhalation risks to California communities from airborne agricultural pesticides by probability distribution analysis using ambient air data provided by the California Air Resources Board and the California Department of Pesticide Regulation. The pesticides evaluated include chloropicrin, chlorothalonil, chlorpyrifos, S,S,S-tributyl phosphorotrithioate, diazinon, 1,3-dichloropropene, dichlorvos (naled breakdown product), endosulfan, eptam, methidathion, methyl bromide, methyl isothiocyanate (MITC; metam sodium breakdown product), molinate, propargite, and simazine. Risks were estimated for the median and 75th and 95th percentiles of probability (50, 25, and 5% of the exposed populations). Exposure estimates greater than or equal to noncancer reference values occurred for 50% of the exposed populations (adults and children) for MITC subchronic and chronic exposures, methyl bromide subchronic exposures (year 2000 monitoring), and 1,3-dichloropropene subchronic exposures (1990 monitoring). Short-term chlorpyrifos exposure estimates exceeded the acute reference value for 50% of children (not adults) in the exposed population. Noncancer risks were uniformly higher for children due to a proportionately greater inhalation rate-to-body weight ratio compared to adults and other factors. Target health effects of potential concern for these exposures include neurologic effects (methyl bromide and chlorpyrifos) and respiratory effects (1,3-dichloropropene and MITC). The lowest noncancer risks occurred for simazine and chlorothalonil. Lifetime cancer risks of one-in-a-million or greater were estimated for 50% of the exposed population for 1,3-dichloropropene (1990 monitoring) and 25% of the exposed populations for methidathion and molinate. Pesticide vapor pressure was found to be a better predictor of inhalation risk compared to other methods of ranking pesticides as potential toxic air contaminants. PMID:12460795

  6. Community exposures to airborne agricultural pesticides in California: ranking of inhalation risks.

    PubMed Central

    Lee, Sharon; McLaughlin, Robert; Harnly, Martha; Gunier, Robert; Kreutzer, Richard

    2002-01-01

    We assessed inhalation risks to California communities from airborne agricultural pesticides by probability distribution analysis using ambient air data provided by the California Air Resources Board and the California Department of Pesticide Regulation. The pesticides evaluated include chloropicrin, chlorothalonil, chlorpyrifos, S,S,S-tributyl phosphorotrithioate, diazinon, 1,3-dichloropropene, dichlorvos (naled breakdown product), endosulfan, eptam, methidathion, methyl bromide, methyl isothiocyanate (MITC; metam sodium breakdown product), molinate, propargite, and simazine. Risks were estimated for the median and 75th and 95th percentiles of probability (50, 25, and 5% of the exposed populations). Exposure estimates greater than or equal to noncancer reference values occurred for 50% of the exposed populations (adults and children) for MITC subchronic and chronic exposures, methyl bromide subchronic exposures (year 2000 monitoring), and 1,3-dichloropropene subchronic exposures (1990 monitoring). Short-term chlorpyrifos exposure estimates exceeded the acute reference value for 50% of children (not adults) in the exposed population. Noncancer risks were uniformly higher for children due to a proportionately greater inhalation rate-to-body weight ratio compared to adults and other factors. Target health effects of potential concern for these exposures include neurologic effects (methyl bromide and chlorpyrifos) and respiratory effects (1,3-dichloropropene and MITC). The lowest noncancer risks occurred for simazine and chlorothalonil. Lifetime cancer risks of one-in-a-million or greater were estimated for 50% of the exposed population for 1,3-dichloropropene (1990 monitoring) and 25% of the exposed populations for methidathion and molinate. Pesticide vapor pressure was found to be a better predictor of inhalation risk compared to other methods of ranking pesticides as potential toxic air contaminants. PMID:12460795

  7. ET-1 Stimulates Superoxide Production by eNOS Following Exposure of Vascular Endothelial Cells to Endotoxin.

    PubMed

    Gopalakrishna, Deepak; Pennington, Samantha; Karaa, Amel; Clemens, Mark G

    2016-07-01

    It has been shown that microcirculation is hypersensitized to endothelin1 (ET-1) following endotoxin (lipopolysaccharide [LPS]) treatment leading to an increased vasopressor response. This may be related in part to decreased activation of endothelial nitric oxide synthase (eNOS) by ET-1. eNOS can also be uncoupled to produce superoxide (O2). This aberrant eNOS activity could further contribute to the hyperconstriction and injury caused by ET-1 following LPS. We therefore tested whether LPS affects ROS production by vascular endothelial cells and whether and how this effect is altered by ET-1. Human umbilical vein endothelial cells (HUVEC) or human microvascular endothelial cells (HMEC) were subjected to a 6-h treatment with LPS (250 ng/mL) or LPS and sepiapterin (100 μM) followed by a 30-min treatment with 100 μM L-Iminoethyl Ornithine (L-NIO) an irreversible eNOS inhibitor and 30-min treatment with ET-1 (10 nM). Conversion of [H]L-arginine to [H]L-citrulline was used to measure eNOS activity. Superoxide dismutase (SOD) inhibitable reduction of Cytochrome-C, dihydro carboxy fluorescein (DCF), and Mitosox was used to estimate ROS. LT-SDS PAGE was used to assess the degree of monomerization of the eNOS homodimer. Stimulation of HUVECs with ET-1 significantly increased NO synthesis by 1.4-fold (P < 0.05). ET-1 stimulation of LPS-treated HUVECs failed to increase NO production. Western blot for eNOS protein showed no change in eNOS protein levels. LPS alone resulted in an insignificant increase in ROS production as measured by cytochrome C that was increased 4.6-fold by ET-1 stimulation (P < 0.05). L-NIO significantly decreased ET-1-induced ROS production (P < 0.05). Sepiapterin significantly decreased ROS production in both; unstimulated and ET-1-stimulated LPS-treated groups, but did not restore NO production. DCF experiments confirmed intracellular ROS while Mitosox suggested a non-mitochondrial source. ET-1 treatment following a chronic LPS stress

  8. Airborne irritant contact dermatitis and conjunctivitis after occupational exposure to chlorothalonil in textiles.

    PubMed

    Lensen, Gerda; Jungbauer, Frank; Gonçalo, Margarida; Coenraads, Pieter Jan

    2007-09-01

    Chlorothalonil (tetrachloro-1,3-benzenedicarbonitrile, CAS 1897-45-6) is a pesticide that has been on the market for many years. It is used as a fungicide in agriculture, horticulture, and floriculture; as a wood preservative; and in paint. We report an epidemic of airborne irritant contact dermatitis, conjunctivitis, and upper airway complaints among seamstresses in a Portuguese trailer tent factory, which we attribute to chlorothalonil. All exposed workers had work-related skin symptoms. After patch testing, we showed that none of these were of allergic origin. Instead of allergic reactions, we noticed a delayed type of irritation after 72 hr to chlorothalonil and to the textile extracts containing high concentrations of chlorothalonil. Although allergic and irritant contact dermatitis from chlorothalonil has been described before, this is, as far as we know, the first time that a delayed type of dermatitis, conjunctivitis, and upper airway irritation after exposure to chlorothalonil in tent-cloth is described. PMID:17680869

  9. Airborne isocyanate exposures in the collision repair industry and a comparison to occupational exposure limits.

    PubMed

    Reeb-Whitaker, Carolyn; Whittaker, Stephen G; Ceballos, Diana M; Weiland, Elisa C; Flack, Sheila L; Fent, Kenneth W; Thomasen, Jennifer M; Trelles Gaines, Linda G; Nylander-French, Leena A

    2012-01-01

    Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 μg/m(3) for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 μg NCO/m(3) for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UK-HSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OR-OSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or

  10. Airborne Isocyanate Exposures in the Collision Repair Industry and a Comparison to Occupational Exposure Limits

    PubMed Central

    Reeb-Whitaker, Carolyn; Whittaker, Stephen G.; Ceballos, Diana M.; Weiland, Elisa C.; Flack, Sheila L.; Fent, Kenneth W.; Thomasen, Jennifer M.; Gaines, Linda G. Trelles; Nylander-French, Leena A.

    2014-01-01

    Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 μg/m3 for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 μg NCO/m3 for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UKHSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OROSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or

  11. Anxiety affecting parkinsonian outcome and motor efficiency in adults of an Ohio community with environmental airborne manganese exposure.

    EPA Science Inventory

    Manganese (Mn) is a nutrient and neurotoxicant sometimes associated with mood, motor and neurological effects. Reports of health effects from occupational exposure to Mn are well known, but the reported links to environmental airborne Mn (Mn-Air) are less conclusive. Marietta, OH...

  12. Characterization of Exposures to Airborne Nanoscale Particles During Friction Stir Welding of Aluminum

    PubMed Central

    Pfefferkorn, Frank E.; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; Mccarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M. Abbas; Gruetzmacher, George; Hoover, Mark D.

    2010-01-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 μm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 μm) with 1-s resolution, lung deposited surface areas, and PM2.5 concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 μm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at ∼30 and ∼550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at ∼4.0 × 105 particles cm−3, whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm−3, depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10–100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) μg m−3; the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may exist, especially in larger scale industrial

  13. Characterization of exposures to airborne nanoscale particles during friction stir welding of aluminum.

    PubMed

    Pfefferkorn, Frank E; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; McCarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M Abbas; Gruetzmacher, George; Hoover, Mark D

    2010-07-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 microm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 microm) with 1-s resolution, lung deposited surface areas, and PM(2.5) concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 microm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at approximately 30 and approximately 550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at approximately 4.0 x 10(5) particles cm(-3), whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm(-3), depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10-100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) microg m(-3); the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may

  14. The effect of bacterial endotoxin of phagocytosis of Tetrahymena and serotonin induced imprinting.

    PubMed

    Kovács, G; Nagy, S U; Csaba, G

    1986-01-01

    Endotoxin inhibited the phagocytosis of Tetrahymena pyriformis after a short exposure and, to a lesser degree, after repeated treatments during one week (about 35 generations). Endotoxin also prevented the development of serotonin imprinting. Detoxified endotoxin (Tolerin) affected the phagocytosis of Tetrahymena much less, indicating that the lipid-A part of the molecule may account for the membrane-toxic effect.

  15. Chronic disease and early exposure to air-borne mixtures. 2. Exposure assessment

    SciTech Connect

    James Argo

    2007-10-15

    This work is part of a larger study of the impact of early exposure to releases from industry on the etiology of cancer. Releases from all kraft and sulfite mills, coke ovens, oil refineries, copper, nickel, and lead/zinc smelters operating in Canada during the exposure period of 1967-1970 have been determined. All plumes have been expressed in g BaP eq/d using the RASH methodology. The releases have been divided into process, boiler fuel, dioxin, and SO{sub 2} emissions. Combustion sources have been defined with FIREv6.23. Dioxin congenors are expected in all source types when the boiler fuel is heavy fuel oil, wood or wood bark, or coal. All about 90 communities examined have an inverted sex ratio. 53 refs., 2 figs., 4 tabs.

  16. Arsenic relative bioavailability from diet and airborne exposures: Implications for risk assessment.

    PubMed

    Yager, Janice W; Greene, Tracy; Schoof, Rosalind A

    2015-12-01

    Major human environmental health concern has been associated with inorganic arsenic (iAs) in drinking water in which dissolved iAs is highly bioavailable. More recently health concerns have been raised regarding the extent of iAs exposure via food and other potential sources. Arsenic relative bioavailability (RBA) in soil is known to be variable; the extent and role of iAs bioavailability in food are not well characterized. iAs in coal fly ash and bottom ash are other potential exposure media for which RBA has not been well characterized. A comprehensive literature search was conducted to support evaluation of the contribution of food and coal fly ash to iAs exposure. Few studies were found that investigated bioavailability associated with As-containing coal ash or airborne As-containing particles; estimated bioavailability in these studies ranged from 11% to 50%. The implications and potential usefulness of iAs bioavailability associated with inhalation exposure to human health risk assessment remain unknown at this time. Main sources of dietary iAs intake in the U.S. include rice and other grains, vegetables, and fruits. Due to low concentrations of iAs, seafood is not a primary contributor to dietary iAs intake. Three general kinds of food studies were identified: studies of As bioaccessibility in composites, As bioavailability and bioaccessibility in specific foods, and As consumption and urinary excretion in human volunteers. One in vivo study was identified that examined As bioavailability in food. A variety of experimental in vitro gastro-intestinal protocols have been used, however, few studies have included As speciation before and after the in vitro extraction. Current data suggest that the bioaccessibility of iAs in rice is quite high, typically 70% or more indicating that iAs in rice is highly bioavailable. Adjusting for RBA may not have a meaningful impact on iAs exposure estimates for rice-based foods. PMID:26225742

  17. Heavy incense burning in temples promotes exposure risk from airborne PMs and carcinogenic PAHs.

    PubMed

    Chiang, Kuo-Chih; Liao, Chung-Min

    2006-12-15

    We present the mechanistic-based exposure and risk models, appraised with reported empirical data, to assess how the human exposure to airborne particulate matters (PMs) and carcinogenic polycyclic aromatic hydrocarbons (PAHs) during heavy incense burning episodes in temples. The models integrate size-dependent PM levels inside a temple from a published exploratory study associated with a human expiratory tract (HRT) model taking into account the personal exposure levels and size distributions in the HRT. The probabilistic exposure profiles of total-PAH levels inside a temple and internal PAHs doses are characterized by a physiologically based pharmacokinetic (PBPK) model with the reconstructed dose-response relationships based on an empirical three-parameter Hill equation model, describing PAHs toxicity for DNA adducts formation and lung tumor incidence responses in human white blood cells and lung. Results show that the alveolar-interstitial (AI) region has a lower mass median diameter (0.29 microm) than that in extrathoracic (ET(1), 0.37 microm), brochial (BB, 0.36 microm) and bronchiolar (bb, 0.32 microm) regions. The 50% probability (risk=0.5) of exceeding the DNA adducts frequency (DA(f)) ratio of 1.28 (95% CI: 0.55-2.40) and 1.78 (95% CI: 0.84-2.95) for external exposure of B[a]P and B[a]P(eq), respectively. The 10% (risk=0.1) probability or more of human affected by lung tumor is approximately 7.62x10(-5)% (95% CI: 3.39x10(-5)-1.71x10(-4)%) and 3.87x10(-4)% (95% CI: 1.72x10(-4)-8.69x10(-4)%) for internal exposure of B[a]P and B[a]P(eq), respectively. Our results implicate that exposure to smoke emitted from heavy incense burning may promote lung cancer risk. Our study provides a quantitative basis for objective risk prediction of heavy incense burning exposure in temples and for evaluating the effectiveness of management.

  18. Acute respiratory effects of endotoxin-contaminated machining fluid aerosols in guinea pigs.

    PubMed

    Gordon, T

    1992-07-01

    Exposure to machining fluid aerosols in the automotive industry is associated with a variety of respiratory symptoms including cross-shift changes in pulmonary function, cough, asthma, and phlegm. Lubricating and cooling fluids used in machining operations are predominantly water and thus are susceptible to microbial growth. In the present study, the role of endotoxin in the acute pulmonary injury produced by machining fluid aerosols was examined in guinea pigs. Animals were exposed to nebulized water, unused machining fluid, or used machining fluid. At the end of a 3-hr exposure, specific airway conductance (SGaw) was not affected by exposure to the vehicle water, but was decreased in a dose-dependent manner by exposure to aerosols of the used machining fluid. SGaw decreased from preexposure baseline values by 0, 7, and 40% in animals exposed to 1, 10, and 100 mg/m3 used machining fluid, respectively. These exposure levels also produced acute lung injury as evidenced by changes in cellular and biochemical indices in lavage fluid. These adverse respiratory effects may have been due to microbial contamination of the used machining fluid as the aerosol exposures were associated with airborne endotoxin concentrations of 0.3, 1.9, and 5.3 micrograms/m3, respectively. Animals exposed to aerosols of the endotoxin-free unused machining fluid had no statistically significant adverse functional, cellular, or biochemical effects except for a fourfold increase in neutrophils at 100 mg/m3. These results suggest that contamination of machining fluid during use or storage may lead to the adverse respiratory effects of aerosolized machining fluids.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Airborne nanoparticle exposures while using constant-flow, constant-velocity, and air-curtain-isolated fume hoods.

    PubMed

    Tsai, Su-Jung Candace; Huang, Rong Fung; Ellenbecker, Michael J

    2010-01-01

    Tsai et al. (Airborne nanoparticle exposures associated with the manual handling of nanoalumina and nanosilver in fume hoods. J Nanopart Res 2009; 11: 147-61) found that the handling of dry nanoalumina and nanosilver inside laboratory fume hoods can cause a significant release of airborne nanoparticles from the hood. Hood design affects the magnitude of release. With traditionally designed fume hoods, the airflow moves horizontally toward the hood cupboard; the turbulent airflow formed in the worker wake region interacts with the vortex in the constant-flow fume hood and this can cause nanoparticles to be carried out with the circulating airflow. Airborne particle concentrations were measured for three hood designs (constant-flow, constant-velocity, and air-curtain hoods) using manual handling of nanoalumina particles. The hood operator's airborne nanoparticle breathing zone exposure was measured over the size range from 5 nm to 20 mum. Experiments showed that the exposure magnitude for a constant-flow hood had high variability. The results for the constant-velocity hood varied by operating conditions, but were usually very low. The performance of the air-curtain hood, a new design with significantly different airflow pattern from traditional hoods, was consistent under all operating conditions and release was barely detected. Fog tests showed more intense turbulent airflow in traditional hoods and that the downward airflow from the double-layered sash to the suction slot of the air-curtain hood did not cause turbulence seen in other hoods. PMID:19933309

  20. Occupational Exposure Assessment of Airborne Chemical Contaminants Among Professional Ski Waxers

    PubMed Central

    Freberg, Baard Ingegerdsson; Olsen, Raymond; Daae, Hanne Line; Hersson, Merete; Thorud, Syvert; Ellingsen, Dag G.; Molander, Paal

    2014-01-01

    Background: Ski waxes are applied onto the skis to improve the performance. They contain different chemical substances, e.g. perfluoro-n-alkanes. Due to evaporation and sublimation processes as well as mechanically generated dust, vapours, fumes, and particulates can contaminate the workroom atmosphere. The number of professional ski waxers is increasing, but occupational exposure assessments among professional ski waxers are lacking. Objectives: The aim was to assess exposure to airborne chemical contaminants among professional ski waxers. It was also a goal to construct a ventilation system designed for ski waxing work operations. Methods: Forty-five professional ski waxers were included. Personal measurements of the inhalable and the respirable aerosol mass fractions were executed in 36 different waxing cabins using Conical Inhalable Sampler cassettes equipped with 37-mm PVC filters (5 µm) and Casella respirable cyclones equipped with 37-mm PVC filters (0.8 µm), respectively. Volatile organic components were collected using Anasorb CSC charcoal tubes. To examine time trends in exposure patterns, stationary real-time measurements of the aerosol mass fractions were conducted using a direct-reading Respicon® sampler. Results: Mean aerosol particle mass concentrations of 3.1 mg·m−3 (range: 0.2–12.0) and 6.2 mg·m−3 (range: 0.4–26.2) were measured in the respirable and inhalable aerosol mass fractions, respectively. Real-time aerosol sampling showed large variations in particle concentrations, with peak exposures of ~10 and 30 mg·m−3 in the respirable and the inhalable aerosol particle mass fractions, respectively. The custom-made ventilation system reduced the concentration of all aerosol mass fractions by more than 90%. PMID:24607772

  1. A Monte Carlo program to calculate the exposure rate from airborne radioactive gases inside a nuclear reactor containment building.

    PubMed

    Sherbini, S; Tamasanis, D; Sykes, J; Porter, S W

    1986-12-01

    A program was developed to calculate the exposure rate resulting from airborne gases inside a reactor containment building. The calculations were performed at the location of a wall-mounted area radiation monitor. The program uses Monte Carlo techniques and accounts for both the direct and scattered components of the radiation field at the detector. The scattered component was found to contribute about 30% of the total exposure rate at 50 keV and dropped to about 7% at 2000 keV. The results of the calculations were normalized to unit activity per unit volume of air in the containment. This allows the exposure rate readings of the area monitor to be used to estimate the airborne activity in containment in the early phases of an accident. Such estimates, coupled with containment leak rates, provide a method to obtain a release rate for use in offsite dose projection calculations.

  2. Airborne exposure limits for chemical and biological warfare agents: is everything set and clear?

    PubMed

    Sabelnikov, Alex; Zhukov, Vladimir; Kempf, C Ruth

    2006-08-01

    Emergency response strategies (guidelines) for biological, chemical, nuclear, or radiological terrorist events should be based on scientifically established exposure limits for all the agents or materials involved. In the case of a radiological terrorist event, emergency response guidelines (ERG) have been worked out. In the case of a terrorist event with the use of chemical warfare (CW) agents the situation is not that clear, though the new guidelines and clean-up values are being generated based on re-evaluation of toxicological and risk data. For biological warfare (BW) agents, such guidelines do not yet exist. In this paper the current status of airborne exposure limits (AELs) for chemical and biological warfare (CBW) agents are reviewed. Particular emphasis is put on BW agents that lack such data. An efficient, temporary solution to bridge the gap in experimental infectious data and to set provisional AELs for BW agents is suggested. It is based on mathematically generated risks of infection for BW agents grouped by their alleged ID50 values in three categories: with low, intermediate and high ID50 values.

  3. Exposure vs toxicity levels of airborne quartz, metal and carbon particles in cast iron foundries.

    PubMed

    Moroni, Beatrice; Viti, Cecilia; Cappelletti, David

    2014-01-01

    Aerosol dust samples and quartz raw materials from different working stations in foundry plants were characterized in order to assess the health risk in this working environment. Samples were analysed by scanning and transmission electron microscopy coupled with image analysis and microanalysis, and by cathodoluminescence spectroscopy. In addition, the concentration and the solubility degree of Fe and other metals of potential health effect (Mn, Zn and Pb) in the bulk samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Overall, the results indicate substantial changes in quartz crystal structure and texture when passing from the raw material to the airborne dust, which include lattice defects, non-bridging oxygen hole centres and contamination of quartz grains by metal and/or graphite particles. All these aspects point towards the relevance of surface properties on reactivity. Exposure doses have been estimated based on surface area, and compared with threshold levels resulting from toxicology. The possible synergistic effects of concomitant exposure to inhalable magnetite, quartz and/or graphite particles in the same working environment have been properly remarked. PMID:23385294

  4. Occupational exposure to airborne particles and other pollutants in an aviation base.

    PubMed

    Buonanno, Giorgio; Bernabei, Manuele; Avino, Pasquale; Stabile, Luca

    2012-11-01

    The occupational exposure to airborne particles and other pollutants in a high performance jet engine airport was investigated. Three spatial scales were considered: i) a downwind receptor site, ii) close to the airstrip, iii) personal monitoring. Particle number, surface area, mass concentrations and distributions were measured as well as inorganic and organic fractions, ionic fractions and Polycyclic Aromatic Hydrocarbons. Particle number distribution measured at a receptor site presents a mode of 80 nm and an average total concentration of 6.5 × 10(3) part. cm(-3); the chemical analysis shows that all the elements may be attributed to long-range transport from the sea. Particle number concentrations in the proximity of the airstrip show short term peaks during the working day mainly related to takeoff, landing and pre-flight operations of jet engines. Personal exposure of workers highlights a median number concentration of 2.5 × 10(4) part. cm(-3) and 1.7 × 10(4) part. cm(-3) for crew chief and hangar operator. PMID:22771354

  5. Airborne trace element pollution in 11 European cities assessed by exposure of standardised ryegrass cultures

    NASA Astrophysics Data System (ADS)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Breuer, Jörn; Vergne, Philippe; Sanz, María José; Rasmussen, Stine; Ro-Poulsen, Helge; Ribas Artola, Àngela; Peñuelas, Josep; He, Shang; Garrec, Jean Pierre; Calatayud, Vicent

    Within a European biomonitoring programme, Italian ryegrass ( Lolium multiflorum Lam.) was employed as accumulative bioindicator of airborne trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, V, Zn) in urban agglomerations. Applying a highly standardised method, grass cultures were exposed for consecutive periods of four weeks each to ambient air at up to 100 sites in 11 cities during 2000-2002. Results of the 2001 exposure experiments revealed a clear differentiation of trace element pollution within and among local monitoring networks. Pollution was influenced particularly by traffic emissions. Especially Sb, Pb, Cr, Fe, and Cu exhibited a very uneven distribution within the municipal areas with strong accumulation in plants from traffic-exposed sites in the city centres and close to major roads, and moderate to low levels in plants exposed at suburban or rural sites. Accumulation of Ni and V was influenced by other emission sources. The biomonitoring sites located in Spanish city centres featured a much higher pollution load by trace elements than those in other cities of the network, confirming previously reported findings obtained by chemical analyses of dust deposition and aerosols. At some heavily-trafficked sites, legal thresholds for Cu, Pb, and V contents in foodstuff and animal feed were reached or even surpassed. The study confirmed that the standardised grass exposure is a useful and reliable tool to monitor and to assess environmental levels of potentially toxic compounds of particulate matter.

  6. Exposure vs toxicity levels of airborne quartz, metal and carbon particles in cast iron foundries.

    PubMed

    Moroni, Beatrice; Viti, Cecilia; Cappelletti, David

    2014-01-01

    Aerosol dust samples and quartz raw materials from different working stations in foundry plants were characterized in order to assess the health risk in this working environment. Samples were analysed by scanning and transmission electron microscopy coupled with image analysis and microanalysis, and by cathodoluminescence spectroscopy. In addition, the concentration and the solubility degree of Fe and other metals of potential health effect (Mn, Zn and Pb) in the bulk samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Overall, the results indicate substantial changes in quartz crystal structure and texture when passing from the raw material to the airborne dust, which include lattice defects, non-bridging oxygen hole centres and contamination of quartz grains by metal and/or graphite particles. All these aspects point towards the relevance of surface properties on reactivity. Exposure doses have been estimated based on surface area, and compared with threshold levels resulting from toxicology. The possible synergistic effects of concomitant exposure to inhalable magnetite, quartz and/or graphite particles in the same working environment have been properly remarked.

  7. Assessment of airborne asbestos exposure during the servicing and handling of automobile asbestos-containing gaskets.

    PubMed

    Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

    2006-07-01

    Five test sessions were conducted to assess asbestos exposure during the removal or installation of asbestos-containing gaskets on vehicles. All testing took place within an operative automotive repair facility involving passenger cars and a pickup truck ranging in vintage from late 1960s through 1970s. A professional mechanic performed all shop work including engine disassembly and reassembly, gasket manipulation and parts cleaning. Bulk sample analysis of removed gaskets through polarized light microscopy (PLM) revealed asbestos fiber concentrations ranging between 0 and 75%. Personal and area air samples were collected and analyzed using National Institute of Occupational Safety Health (NIOSH) methods 7400 [phase contrast microscopy (PCM)] and 7402 [transmission electron microscopy (TEM)]. Among all air samples collected, approximately 21% (n = 11) contained chrysotile fibers. The mean PCM and phase contrast microscopy equivalent (PCME) 8-h time weighted average (TWA) concentrations for these samples were 0.0031 fibers/cubic centimeters (f/cc) and 0.0017 f/cc, respectively. Based on these findings, automobile mechanics who worked with asbestos-containing gaskets may have been exposed to concentrations of airborne asbestos concentrations approximately 100 times lower than the current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 0.1 f/cc.

  8. Methods of Endotoxin Detection.

    PubMed

    Su, Wenqiong; Ding, Xianting

    2015-08-01

    Endotoxin, present in the outer membrane of all gram-negative bacteria, can pose serious risks to human health, from irreversible shock to death. Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin. With in-depth understanding of endotoxin, biosensors based on endotoxin-sensing components are promising alternatives to pursue in developing low-cost, easy-operation, and fast-response endotoxin detection techniques. This article summarizes the recent advances of endotoxin detection methods with a particular emphasis on optical and electrochemical biosensors based on various sensing elements ranging from nature biomolecules to artificial materials. As the research and technological revolution continues, the highly integrated and miniaturized commercial devices for sensitively and reliably detecting endotoxin will provide a wide range of applications in people's daily life. PMID:25720597

  9. Methods of Endotoxin Detection.

    PubMed

    Su, Wenqiong; Ding, Xianting

    2015-08-01

    Endotoxin, present in the outer membrane of all gram-negative bacteria, can pose serious risks to human health, from irreversible shock to death. Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin. With in-depth understanding of endotoxin, biosensors based on endotoxin-sensing components are promising alternatives to pursue in developing low-cost, easy-operation, and fast-response endotoxin detection techniques. This article summarizes the recent advances of endotoxin detection methods with a particular emphasis on optical and electrochemical biosensors based on various sensing elements ranging from nature biomolecules to artificial materials. As the research and technological revolution continues, the highly integrated and miniaturized commercial devices for sensitively and reliably detecting endotoxin will provide a wide range of applications in people's daily life.

  10. Extracorporeal adsorption of endotoxin.

    PubMed

    Staubach, K H; Rosenfeldt, J A; Veit, O; Bruch, H P

    1997-02-01

    In a porcine endotoxin shock model using a continuous intravenous endotoxin infusion of 250 ng/kg body weight per hour, the cardiorespiratory and hematologic parameters were studied while applying a new on-line polymyxin B immobilized adsorption system. This preliminary report shows that the new adsorbent can remove endotoxin selectively from the circulation and confers a good amount of protection from endotoxin-induced cardiopulmonary decompensation as well as hematologic alterations. Survival time could be extended from 216 min to 313 min. Whereas cardiac output and mean arterial pressure declined critically after 3 h in the controls, the treated group remained stable for another 3 h. These data show that endotoxin adsorption by polymyxin B coupled covalently to acrylic spheres as an adjunctive on-line measure in the septic syndrome seems feasible. PMID:10225785

  11. Indicators of airborne fungal concentrations in urban homes: understanding the conditions that affect indoor fungal exposures.

    PubMed

    Crawford, Judith A; Rosenbaum, Paula F; Anagnost, Susan E; Hunt, Andrew; Abraham, Jerrold L

    2015-06-01

    Indoor fungal exposure can compromise respiratory health. Low-income urban areas are of concern because of high asthma and allergy rates and housing disrepair. Understanding the conditions that affect indoor fungal exposures is important for assessing health risks and for developing mitigation strategies. We examined the types and concentrations of airborne fungi inside and outside of homes in low-income areas of Syracuse, NY as well as the effect of snow cover on fungal levels. At 103 homes, air samples for viable fungi were collected, occupants were interviewed and homes were inspected for visible mold, musty odors, water problems and other factors. Multivariable logistic regression was used to relate high fungal levels to home conditions. Predominant indoor fungi included Cladosporium, Penicillium, Aspergillus, Alternaria and hyaline unknowns. Basidiomycetes and an uncommon genus Acrodontium were also found frequently due to analysis methods developed for this project. With snow cover, outdoor total fungal levels were depressed and indoor concentrations were three times higher than outdoor on average with a maximum of 29 times higher. Visible mold was related to elevated levels of Penicillium (OR 4.11 95% CI 1.37-14.0) and bacteria (OR 3.79 95% CI 1.41-11.2). Musty, moldy odors were associated with elevated concentrations of total fungi (OR 3.48 95% CI 1.13-11.6) and basidiomycetes. Cockroaches, an indicator of moisture, were associated with elevated levels of Penicillium (OR 3.66 95% CI 1.16-13.1) and Aspergillus (OR 4.36 95% CI 1.60-13.4). Increasing relative humidity was associated with higher concentrations of Penicillium, yeasts and basidiomycetes. Visible mold, musty odors, indoor humidity and cockroaches are modifiable factors that were important determinants of indoor fungal exposures. Indoor air investigators should interpret indoor:outdoor fungal ratios cautiously when snow cover is present.

  12. Assessment of airborne asbestos exposure at an asbestos cement sheet and pipe factory in Iran.

    PubMed

    Marioryad, Hossein; Kakooei, Hossein; Shahtaheri, Seyed Jamaleddin; Yunesian, Masud; Azam, Kamal

    2011-07-01

    Iran imports nearly 55,000 metric tons of asbestos per year, and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, asbestos fiber concentrations during AC sheet and pipe manufacturing were measured by phase-contrast microscopy (PCM) and polarized light microscopy (PLM) in 98 personal air samples. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Personal monitoring of fiber levels indicated a range from 0.02 to 0.55PCM f/ml (0.02-0.69PLM f/ml). The AC workers' geometric mean asbestos exposure was 0.09 PCM f/ml (0.11 PLM f/ml), with arithmetic mean of 0.13 PCM f/ml (0.16 PLM f/ml). The observed fiber concentrations in many processes were higher than the threshold limit value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), which is 0.1 f/ml. Based on these findings, the PLM values were approximately 25% higher than PCM values. The SEM data demonstrate that fibrous particles contained chrysotile. The thinnest fiber recognized by SEM had a diameter of 0.2μm. Mean exposure exceeded the TLV for asbestos in pipe molding and finishing (100%) as well as sheet molding and finishing (45.5-83.3%). In conclusion exposure control may be needed to be in compliance with the ACGIH TLV and other guidance levels. Also, with regard to PCM limitations for airborne fiber analysis, the use of microscopic methods other than PCM can be used to improve the techniques used presently.

  13. Indicators of airborne fungal concentrations in urban homes: understanding the conditions that affect indoor fungal exposures.

    PubMed

    Crawford, Judith A; Rosenbaum, Paula F; Anagnost, Susan E; Hunt, Andrew; Abraham, Jerrold L

    2015-06-01

    Indoor fungal exposure can compromise respiratory health. Low-income urban areas are of concern because of high asthma and allergy rates and housing disrepair. Understanding the conditions that affect indoor fungal exposures is important for assessing health risks and for developing mitigation strategies. We examined the types and concentrations of airborne fungi inside and outside of homes in low-income areas of Syracuse, NY as well as the effect of snow cover on fungal levels. At 103 homes, air samples for viable fungi were collected, occupants were interviewed and homes were inspected for visible mold, musty odors, water problems and other factors. Multivariable logistic regression was used to relate high fungal levels to home conditions. Predominant indoor fungi included Cladosporium, Penicillium, Aspergillus, Alternaria and hyaline unknowns. Basidiomycetes and an uncommon genus Acrodontium were also found frequently due to analysis methods developed for this project. With snow cover, outdoor total fungal levels were depressed and indoor concentrations were three times higher than outdoor on average with a maximum of 29 times higher. Visible mold was related to elevated levels of Penicillium (OR 4.11 95% CI 1.37-14.0) and bacteria (OR 3.79 95% CI 1.41-11.2). Musty, moldy odors were associated with elevated concentrations of total fungi (OR 3.48 95% CI 1.13-11.6) and basidiomycetes. Cockroaches, an indicator of moisture, were associated with elevated levels of Penicillium (OR 3.66 95% CI 1.16-13.1) and Aspergillus (OR 4.36 95% CI 1.60-13.4). Increasing relative humidity was associated with higher concentrations of Penicillium, yeasts and basidiomycetes. Visible mold, musty odors, indoor humidity and cockroaches are modifiable factors that were important determinants of indoor fungal exposures. Indoor air investigators should interpret indoor:outdoor fungal ratios cautiously when snow cover is present. PMID:25725196

  14. Geltape method for measurement of work related surface contamination with cobalt containing dust: correlation between surface contamination and airborne exposure.

    PubMed Central

    Poulsen, O M; Olsen, E; Christensen, J M; Vinzent, P; Petersen, O H

    1995-01-01

    OBJECTIVES--The geltape method is a new method for optical measurement of total amount of dust on surfaces. The objectives were to study the potential applicability of this method to measurements of work related cobalt exposure during painting of plates with cobalt dye. METHODS--Consecutive series of work related geltape prints were taken from surfaces inside and outside the ventilation cabins of two plate painters during two full working days. The amount of dust picked up by the geltapes was measured optically with a field monitor. Also, personal air samples were collected on filters at the different work processes. In the laboratory the contents of cobalt on the geltape prints and the filters were measured with inductive coupled plasma atomic emission spectroscopy. RESULTS--The key results were: (a) when the geltape prints were taken from surfaces inside the cabins the optically measured area of the geltapes covered with total dust (area (%)) correlated well with the chemically measured amount of cobalt present on the geltapes. Linear correlation coefficient (R2) was 0.91 for geltape prints taken on the floor and 0.94 for prints taken on the ceiling; (b) the cumulative airborne cobalt exposure, calculated from data on work related exposure by personal sampling, correlated with the area (%) of geltape prints taken from the ceiling of the cabin (R2 = 0.98); (c) the geltape method could be used to distinguish both between work processes with different levels of cobalt exposure, and between plate painters subjected to significant differences in airborne cobalt exposure. CONCLUSION--The geltape method could produce measures of the work related exposures as well as whole day exposure for cobalt. The geltape results correlated with measurements of personal airborne cobalt exposure. In this industry the profile of exposure is well-defined in time, and it seems reasonable to apply this fast and low cost method in routine exposure surveillance to obtain a more detailed

  15. Airborne Contaminants in the TE Lab: How to Reduce Your Exposure.

    ERIC Educational Resources Information Center

    Zeimet, Denis E.; Merrell, Wayne L.

    1995-01-01

    Details the dangers from airborne contaminants in technology education laboratories and ways to protect students from them, including ventilation, acceptable limits, and guidelines for using respirators. (SK)

  16. Prenatal exposure to airborne polycyclic aromatic hydrocarbons and IQ: estimated benefit of pollution reduction.

    PubMed

    Perera, Frederica; Weiland, Katherine; Neidell, Matthew; Wang, Shuang

    2014-08-01

    Outdoor air pollution, largely from fossil fuel burning, is a major cause of morbidity and mortality in the United States, costing billions of dollars every year in health care and loss of productivity. The developing fetus and young child are especially vulnerable to neurotoxicants, such as polycyclic aromatic hydrocarbons (PAH) released to ambient air by combustion of fossil fuel and other organic material. Low-income populations are disproportionately exposed to air pollution. On the basis of the results of a prospective cohort study in a low-income population in New York City (NYC) that found a significant inverse association between child IQ and prenatal exposure to airborne PAH, we estimated the increase in IQ and related lifetime earnings in a low-income urban population as a result of a hypothesized modest reduction of ambient PAH concentrations in NYC of 0.25 ng/m(3). For reference, the current estimated annual mean PAH concentration is ~1 ng/m(3). Restricting to NYC Medicaid births and using a 5 per cent discount rate, we estimated the gain in lifetime earnings due to IQ increase for a single year cohort to be US$215 million (best estimate). Using much more conservative assumptions, the estimate was $43 million. This analysis suggests that a modest reduction in ambient concentrations of PAH is associated with substantial economic benefits to children.

  17. Prenatal exposure to airborne polycyclic aromatic hydrocarbons and IQ: estimated benefit of pollution reduction.

    PubMed

    Perera, Frederica; Weiland, Katherine; Neidell, Matthew; Wang, Shuang

    2014-08-01

    Outdoor air pollution, largely from fossil fuel burning, is a major cause of morbidity and mortality in the United States, costing billions of dollars every year in health care and loss of productivity. The developing fetus and young child are especially vulnerable to neurotoxicants, such as polycyclic aromatic hydrocarbons (PAH) released to ambient air by combustion of fossil fuel and other organic material. Low-income populations are disproportionately exposed to air pollution. On the basis of the results of a prospective cohort study in a low-income population in New York City (NYC) that found a significant inverse association between child IQ and prenatal exposure to airborne PAH, we estimated the increase in IQ and related lifetime earnings in a low-income urban population as a result of a hypothesized modest reduction of ambient PAH concentrations in NYC of 0.25 ng/m(3). For reference, the current estimated annual mean PAH concentration is ~1 ng/m(3). Restricting to NYC Medicaid births and using a 5 per cent discount rate, we estimated the gain in lifetime earnings due to IQ increase for a single year cohort to be US$215 million (best estimate). Using much more conservative assumptions, the estimate was $43 million. This analysis suggests that a modest reduction in ambient concentrations of PAH is associated with substantial economic benefits to children. PMID:24804951

  18. Endotoxins in indoor air and settled dust in primary schools in a subtropical climate.

    PubMed

    Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Clifford, Sam; Morawska, Lidia

    2013-09-01

    Endotoxins can significantly affect the air quality in school environments. However, there is currently no reliable method for the measurement of endotoxins, and there is a lack of reference values for endotoxin concentrations to aid in the interpretation of measurement results in school settings. We benchmarked the "baseline" range of endotoxin concentration in indoor air, together with endotoxin load in floor dust, and evaluated the correlation between endotoxin levels in indoor air and settled dust, as well as the effects of temperature and humidity on these levels in subtropical school settings. Bayesian hierarchical modeling indicated that the concentration in indoor air and the load in floor dust were generally (<95th percentile) <13 EU/m(3) and <24,570 EU/m(2), respectively. Exceeding these levels would indicate abnormal sources of endotoxins in the school environment and the need for further investigation. Metaregression indicated no relationship between endotoxin concentration and load, which points to the necessity for measuring endotoxin levels in both the air and settled dust. Temperature increases were associated with lower concentrations in indoor air and higher loads in floor dust. Higher levels of humidity may be associated with lower airborne endotoxin concentrations. PMID:23927534

  19. Endotoxins in indoor air and settled dust in primary schools in a subtropical climate.

    PubMed

    Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Clifford, Sam; Morawska, Lidia

    2013-09-01

    Endotoxins can significantly affect the air quality in school environments. However, there is currently no reliable method for the measurement of endotoxins, and there is a lack of reference values for endotoxin concentrations to aid in the interpretation of measurement results in school settings. We benchmarked the "baseline" range of endotoxin concentration in indoor air, together with endotoxin load in floor dust, and evaluated the correlation between endotoxin levels in indoor air and settled dust, as well as the effects of temperature and humidity on these levels in subtropical school settings. Bayesian hierarchical modeling indicated that the concentration in indoor air and the load in floor dust were generally (<95th percentile) <13 EU/m(3) and <24,570 EU/m(2), respectively. Exceeding these levels would indicate abnormal sources of endotoxins in the school environment and the need for further investigation. Metaregression indicated no relationship between endotoxin concentration and load, which points to the necessity for measuring endotoxin levels in both the air and settled dust. Temperature increases were associated with lower concentrations in indoor air and higher loads in floor dust. Higher levels of humidity may be associated with lower airborne endotoxin concentrations.

  20. Allergy arising from exposure to airborne contaminants in an insect rearing facility: Health effects and exposure control

    SciTech Connect

    Wolff, D.

    1994-06-01

    In agricultural crop improvement, yield under various stress conditions and limiting factors is assessed experimentally. Of the stresses on plants which affect yield are those due to insects. Ostrinia nubilalis, the European corn borer (corn borer) is a major pest in sweet and field corn in the U.S. There are many ways to fight crop pests such as the corn borer, including (1) application of chemical insecticides, (2) application of natural predators and, (3) improving crop resistance through plant genetics programs. Randomized field trials are used to determine the effectiveness of pest management programs. These trials frequently consist of randomly selected crop plots to which well-defined input regimes are instituted. For example, corn borers might be released onto crop plots in several densities at various stages of crop development, then sprayed with different levels of pesticide. These experiments are duplicated across regions and, in some cases across the country, to determine, in this instance for example, the best pesticide application rate for a given pest density and crop development stage. In order to release these pests onto crop plots, one must have an adequate supply of the insect pest. In winter months studies are carried out in the laboratory to examine chemical and natural pesticide effectiveness, as well as such things as the role of pheromones in moth behavior. The advantage in field trials is that yield data can be garnered directly. In this country, insects are raised for crop research primarily through the US Department of Agriculture, in cooperation with public Land Grant Universities and, by the private sector agricultural concerns - seed companies and others. This study quantifies the airborne allergen exposure of persons working in a Land Grant University entomology lab were allergy to European corn borer was suspected.

  1. Effects of endotoxin on the lactating mouse

    SciTech Connect

    Carr, J.K.

    1985-01-01

    The regulation of endogenous mouse mammary tumor virus (MMTV) sequences in trans by a host gene, the Lps locus on mouse chromosome 4, was suspected from a genetic linkage analysis. The Lps locus mediates the mouse's response to the injection of lipopolysaccharide (LPS) in the responder mouse while mice with the deficient allele are incapable of responding. Others have found that endotoxin exposure reduces milk production in lactating animals. This observation was confirmed in mice and extended by examining /sup 125/I-prolactin binding to liver membranes of lactating mice. Endotoxin treatment of responder mice increases liver prolactin binding within 15 minutes, followed by a decline over 6 hours. Scatchard analysis shows that the immediate increase comes from both increased affinity and abundance of the prolactin receptor. No such change in prolactin binding is seen in the non-responder following endotoxin treatment nor in /sup 125/I-insulin binding in responders.

  2. Dermal Uptake from Airborne Organics as an Important Route of Human Exposure to E-Waste Combustion Fumes.

    PubMed

    Wu, Chen-Chou; Bao, Lian-Jun; Tao, Shu; Zeng, Eddy Y

    2016-07-01

    Skin absorption of gaseous organic contaminants is an important and relevant mechanism in human exposure to such contaminants, but has not been adequately examined. This article demonstrates that dermal uptake from airborne contaminants could be recognized as a significant exposure route for local residents subjecting to combustion fume from e-waste recycling activities. It is particularly true for organic pollutants which have high dermal penetration rates and large skin-air partition coefficients, such as low molecular weight plasticizers and flame retardants. PMID:26937778

  3. Airborne total gaseous mercury and exposure in a Venezuelan mining area.

    PubMed

    Garcia-Sanchez, Antonio; Contreras, Felicia; Adams, Meliton; Santos, Fernando

    2006-10-01

    This paper presents a short-term monitoring study of total gaseous mercury (TGM) in air, and exposure to airborne mercury. The evaluation was carried out in polluted mining sites (El Callao, Venezuela), where for decades mercury has been used in diverse stages of gold mining activities. The contamination is mainly due to emission of Hg0 during gold amalgamation and burning, which can cause direct human health risks. Total gaseous mercury (TGM) in air was analysed in mill, jewellery and indoor house sites, and at different heights (height profiles near the surface) at polluted and not polluted sites. Mercury concentration in air was measured with a portable mercury analyser (Lumex Ra-915+). Time weighted average mercury (TWA) was calculated for the evaluation of mercury exposure. TWA values ranged between 0.28 microg m(-3) and >100 microg m(-3). These measurements were done during sunny and dry days. In the case of mills and gold workshops, the values were over the limit recommended by the World Health Organization to exposure (25 microg m(-3)) and NIOSH limit (50 microg m(-3)). Indoors in a house, the air Hg average value was 2.58 microg m(-3) exceeding EPA (0.3 microg m(-3)) and ATSDR (1 microg m(-3)) guidelines. The mercury concentration at different height profiles, varied between 1766 microg m(-3) and 0.014 microg m(-3). Mercury height profiles were described by a power function model of the form c(Hg) = ah(-b), where a parameter describes the magnitude of Hg emission. For polluted sites there was a significant correlation between a and Hg in soil or Hg emission from soil to air, while b is only significantly correlated with air temperature. An air and soil mercury measurement transect was carried out at a mill site up to a distance of 1000 m, and it was observed that the air mercury concentration decreases with increasing distance from the mill site, and inversely to Hg soil content.

  4. Endotoxin in meningococcal infections.

    PubMed Central

    Tubbs, H R

    1980-01-01

    26 children with meningococcal infections were studied to find out the relationaship between plasma and cerebrospinal fluid levels of endotoxin, the clinical outcome, the level of antigen in plasma and cerebrospinal fluid, and indices of complement activation and disseminated intravascular coagulation. No association was found between endotoxin levels and the other factors. A high cerebrospinal fluid antigen level in patients with meningitis was associated with a poor prognosis. PMID:6776899

  5. Establishment of Airborne Nanoparticle Exposure Chamber System to Assess Nano TiO2 Induced Mice Lung Effects

    NASA Astrophysics Data System (ADS)

    Chen, Chia-Hua; Li, Jui-Ping; Huang, Nai-Chun; Yang, Chung-Shi; Chen, Jen-Kun

    2011-12-01

    A great many governments have schemed their top priority to support the research and development of emerging nanotechnology, which lead to increasing products containing nanomaterials. However, platforms and protocols to evaluate the safety of nanomaterials are not yet established. We therefore design and fabricate a nanoparticle exposure chamber system (NECS) and try to standardize protocols to assess potential health risk of inhalable nanoparticles. This platform comprises: (1) nano-aerosol generators to produce homogeneous airborne nanoparticles, (2) double isolated container to prevent from unexpected exposure to humans, (3) gas supply system for housing animals or incubating cultured cells, and (4) system for automatic control and airborne nanoparticle analysis. The NECS providing multiple functions includes: (1) a secure environment to handle nanomaterials, (2) real-time measurement for the size and distribution of airborne nanoparticles, (3) SOP of safety evaluation for nanomaterials, and (4) key technology for the development of inhalable pharmaceuticals. We used NECS to mimic occupational environment for exploring potential adverse effects of TiO2 nanoparticles. The adult male ICR mice were exposed to 25nm, well-characterized TiO2 particles for 1 and 4 weeks. More than 90% of the inhaled TiO2 nanoparticles deposit in lung tissue, which tends to be captured by alveolar macrophages. Pulmonary function test does not show significant physiological changes between one and 4 weeks exposure. For plasma biochemistry analysis, there are no obvious inflammation responses after exposure for one and 4 weeks; however, disruption of alveolar septa and increased thickness of alveolar epithelial cells were observed. According to our results, the NECS together with our protocols show comprehensive integration and ideally fit the standard of OECD guildelines-TG403, TG412, TG413; it can be further customized to fulfill diverse demands of industry, government, and third party

  6. [Review on characteristics and detecting assay of bacterial endotoxin contamination in water environment].

    PubMed

    Zhang, Can; Liu, Wen-Jun; Zhang, Ming-Lu; Tian, Fang; Yang, Yi; An, Dai-Zhi

    2014-04-01

    Endotoxins, also known as lipopolysaccharide complexes, are anchored in the outer membrane cell wall of most Gram-negative bacteria and some cyanobacteria. They are continuously released to environment during cell decay. Being common pyrogens and highly immunogenic molecules, endotoxins are related to many human diseases. Due to the tolerances and thermo-stability of endotoxin molecules, they were hard to be removed by common methods. The health risk caused by the endotoxin contamination in drinking water and water environment by various exposure pathways have attracted more and more attention in recent years. In this paper, the physical and chemical properties, biological activities and detection assay of the endotoxin contamination were reviewed, and interfere factors of the main assay, the LAL/TAL (Limulus amebocyte lysate/Tachypleus amebocyte lysate) assay, for detecting endotoxin in water sample were investigated, and the development tendency of the endotoxin detection assay was analyzed.

  7. Exposure of workers to airborne microorganisms in open-air swine houses.

    PubMed

    Chang, C W; Chung, H; Huang, C F; Su, H J

    2001-01-01

    This study quantified the levels of airborne microorganisms in six swine farms with more than 10,000 pigs in subtropical Taiwan. We evaluated breeding, growing, and finishing stalls, which were primarily open-air buildings, as well as partially enclosed farrowing and nursery piggeries. Airborne culturable bacteria, gram-negative bacteria, and fungi were placed on appropriate media by using an all-glass impinger or single-stage Andersen microbial sampler. Results showed that mean concentrations of culturable bacteria and gram-negative bacteria were 3.3 x 10(5) and 143.7 CFU/m(3), respectively. The concentration of airborne culturable fungi was about 10(3) CFU/m(3), with Cladosporium the predominant genus. The highest airborne levels of culturable bacteria and gram-negative bacteria were identified in the finishing units. The air of the nursery stalls was the least contaminated with culturable and gram-negative bacteria. Irregular and infrequent cleaning, high pig density, no separation of wastes from pen floors, and accumulation of water as a result of the processes for cleaning and reducing pig temperature possibly compromise the benefits of the open characteristic of the finishing units with respect to airborne bacterial concentration.

  8. Comparison of endotoxin levels and gram-negative bacteria under different conditions in microbial laboratories and a biowaste site.

    PubMed

    Hwang, Sung Ho; Park, Dong Uk; Joo, Se Ik; Park, Hyun Hee; Yoon, Chung Sik

    2011-09-01

    In this study, we assessed airborne endotoxin levels in university laboratories, hospital diagnostic laboratories, and a biowaste site. We also investigated indoor and outdoor sampling, sampling site, type of ventilation system, presence of open biowaste boxes, weather, and detection of Gram-negative bacteria (GNB). A total of 69 air samples were collected from 11 facilities in three institutions. Average total airborne endotoxin levels ranged from <0.01 to 10.02 EU m(-3), with an overall mean of 1.03 EU m(-3). Endotoxin levels were high in window-ventilated facilities, in facilities in which GNB were detected; levels were also high when it was rainy (all ps<0.05). Endotoxin levels were significantly correlated with humidity (r=0.70, p<0.01). The presence of HVAC; humidity; and the presence of open biowaste boxes affect endotoxin levels in laboratories. PMID:21726888

  9. Biosensor of endotoxin and sepsis

    NASA Astrophysics Data System (ADS)

    Shao, Yang; Wang, Xiang; Wu, Xi; Gao, Wei; He, Qing-hua; Cai, Shaoxi

    2001-09-01

    To investigate the relation between biosensor of endotoxin and endotoxin of plasma in sepsis. Method: biosensor of endotoxin was designed with technology of quartz crystal microbalance bioaffinity sensor ligand of endotoxin were immobilized by protein A conjugate. When a sample soliton of plasma containing endotoxin 0.01, 0.03, 0.06, 0.1, 0.5, 1.0Eu, treated with perchloric acid and injected into slot of quartz crystal surface respectively, the ligand was released from the surface of quartz crystal to form a more stable complex with endotoxin in solution. The endotoxin concentration corresponded to the weight change on the crystal surface, and caused change of frequency that occurred when desorbed. The result was biosensor of endotoxin might detect endotoxin of plasma in sepsis, measurements range between 0.05Eu and 0.5Eu in the stop flow mode, measurement range between 0.1Eu and 1Eu in the flow mode. The sensor of endotoxin could detect the endotoxin of plasm rapidly, and use for detection sepsis in clinically.

  10. Perioperative anti-endotoxin strategies.

    PubMed

    Houdijk, A P; Meijer, C; Cuesta, M A; Meyer, S; Van Leeuwen, P A

    1997-01-01

    Lipopolysaccharides from the outer membrane of Gram-negative bacteria are potent stimuli for the production of numerous cytokines by the immune cells. The systemic inflammatory response to these gut-derived endotoxins is therefore dependent on the responsiveness of the immune system. This paper presents results on anti-endotoxin strategies and the responsiveness to endotoxin in animal models of liver failure. Following partial hepatectomy in the normal rat, anti-endotoxin treatment using the enteral endotoxin binder cholestyramine and the bactericidal permeability-increasing protein showed beneficial effects in terms of reducing the exaggerated metabolic and inflammatory responses. Similar beneficial effects of gut endotoxin restriction were found in bile duct ligated rats subjected to a laparotomy. The beneficial effects of anti-endotoxin strategies in these models were explained by completely different mechanisms. In partial hepatectomized rats the effects were explained by the direct inhibition of the stimulatory action of endotoxin on immune cells preventing an exaggerated inflammatory response. In contrast, in postoperative BDL rats the effects of anti-endotoxin therapy were explained by the restoration of endotoxin sensitivity of the immune cells resulting in an inflammatory response necessary for an adequate reaction to surgery. These different mechanism will be discussed in the light of the phenomenon of endotoxin tolerance.

  11. Kinetics of Hydrothermal Inactivation of Endotoxins

    PubMed Central

    Li, Lixiong; Wilbur, Chris L.; Mintz, Kathryn L.

    2011-01-01

    A kinetic model was established for the inactivation of endotoxins in water at temperatures ranging from 210°C to 270°C and a pressure of 6.2 × 106 Pa. Data were generated using a bench scale continuous-flow reactor system to process feed water spiked with endotoxin standard (Escherichia coli O113:H10). Product water samples were collected and quantified by the Limulus amebocyte lysate assay. At 250°C, 5-log endotoxin inactivation was achieved in about 1 s of exposure, followed by a lower inactivation rate. This non-log-linear pattern is similar to reported trends in microbial survival curves. Predictions and parameters of several non-log-linear models are presented. In the fast-reaction zone (3- to 5-log reduction), the Arrhenius rate constant fits well at temperatures ranging from 120°C to 250°C on the basis of data from this work and the literature. Both biphasic and modified Weibull models are comparable to account for both the high and low rates of inactivation in terms of prediction accuracy and the number of parameters used. A unified representation of thermal resistance curves for a 3-log reduction and a 3 D value associated with endotoxin inactivation and microbial survival, respectively, is presented. PMID:21193667

  12. Reliability and validity of expert assessment based on airborne and urinary measures of nickel and chromium exposure in the electroplating industry

    PubMed Central

    Chen, Yu-Cheng; Coble, Joseph B; Deziel, Nicole C.; Ji, Bu-Tian; Xue, Shouzheng; Lu, Wei; Stewart, Patricia A; Friesen, Melissa C

    2014-01-01

    The reliability and validity of six experts’ exposure ratings were evaluated for 64 nickel-exposed and 72 chromium-exposed workers from six Shanghai electroplating plants based on airborne and urinary nickel and chromium measurements. Three industrial hygienists and three occupational physicians independently ranked the exposure intensity of each metal on an ordinal scale (1–4) for each worker's job in two rounds: the first round was based on responses to an occupational history questionnaire and the second round also included responses to an electroplating industry-specific questionnaire. Spearman correlation (rs) was used to compare each rating's validity to its corresponding subject-specific arithmetic mean of four airborne or four urinary measurements. Reliability was moderately-high (weighted kappa range=0.60–0.64). Validity was poor to moderate (rs= -0.37–0.46) for both airborne and urinary concentrations of both metals. For airborne nickel concentrations, validity differed by plant. For dichotomized metrics, sensitivity and specificity were higher based on urinary measurements (47–78%) than airborne measurements (16–50%). Few patterns were observed by metal, assessment round, or expert type. These results suggest that, for electroplating exposures, experts can achieve moderately-high agreement and (reasonably) distinguish between low and high exposures when reviewing responses to in-depth questionnaires used in population-based case-control studies. PMID:24736099

  13. Reliability and validity of expert assessment based on airborne and urinary measures of nickel and chromium exposure in the electroplating industry.

    PubMed

    Chen, Yu-Cheng; Coble, Joseph B; Deziel, Nicole C; Ji, Bu-Tian; Xue, Shouzheng; Lu, Wei; Stewart, Patricia A; Friesen, Melissa C

    2014-11-01

    The reliability and validity of six experts' exposure ratings were evaluated for 64 nickel-exposed and 72 chromium-exposed workers from six Shanghai electroplating plants based on airborne and urinary nickel and chromium measurements. Three industrial hygienists and three occupational physicians independently ranked the exposure intensity of each metal on an ordinal scale (1-4) for each worker's job in two rounds: the first round was based on responses to an occupational history questionnaire and the second round also included responses to an electroplating industry-specific questionnaire. The Spearman correlation (r(s)) was used to compare each rating's validity to its corresponding subject-specific arithmetic mean of four airborne or four urinary measurements. Reliability was moderately high (weighted kappa range=0.60-0.64). Validity was poor to moderate (r(s)=-0.37-0.46) for both airborne and urinary concentrations of both metals. For airborne nickel concentrations, validity differed by plant. For dichotomized metrics, sensitivity and specificity were higher based on urinary measurements (47-78%) than airborne measurements (16-50%). Few patterns were observed by metal, assessment round, or expert type. These results suggest that, for electroplating exposures, experts can achieve moderately high agreement and (reasonably) distinguish between low and high exposures when reviewing responses to in-depth questionnaires used in population-based case-control studies.

  14. Cigarettes vs. e-cigarettes: Passive exposure at home measured by means of airborne marker and biomarkers

    SciTech Connect

    Ballbè, Montse; Martínez-Sánchez, Jose M.; Sureda, Xisca; Fu, Marcela; and others

    2014-11-15

    Background: There is scarce evidence about passive exposure to the vapour released or exhaled from electronic cigarettes (e-cigarettes) under real conditions. The aim of this study is to characterise passive exposure to nicotine from e-cigarettes' vapour and conventional cigarettes' smoke at home among non-smokers under real-use conditions. Methods: We conducted an observational study with 54 non-smoker volunteers from different homes: 25 living at home with conventional smokers, 5 living with nicotine e-cigarette users, and 24 from control homes (not using conventional cigarettes neither e-cigarettes). We measured airborne nicotine at home and biomarkers (cotinine in saliva and urine). We calculated geometric mean (GM) and geometric standard deviations (GSD). We also performed ANOVA and Student's t tests for the log-transformed data. We used Bonferroni-corrected t-tests to control the family error rate for multiple comparisons at 5%. Results: The GMs of airborne nicotine were 0.74 μg/m{sup 3} (GSD=4.05) in the smokers’ homes, 0.13 μg/m{sup 3} (GSD=2.4) in the e-cigarettes users’ homes, and 0.02 μg/m{sup 3} (GSD=3.51) in the control homes. The GMs of salivary cotinine were 0.38 ng/ml (GSD=2.34) in the smokers’ homes, 0.19 ng/ml (GSD=2.17) in the e-cigarettes users’ homes, and 0.07 ng/ml (GSD=1.79) in the control homes. Salivary cotinine concentrations of the non-smokers exposed to e-cigarette's vapour at home (all exposed ≥2 h/day) were statistically significant different that those found in non-smokers exposed to second-hand smoke ≥2 h/day and in non-smokers from control homes. Conclusions: The airborne markers were statistically higher in conventional cigarette homes than in e-cigarettes homes (5.7 times higher). However, concentrations of both biomarkers among non-smokers exposed to conventional cigarettes and e-cigarettes’ vapour were statistically similar (only 2 and 1.4 times higher, respectively). The levels of airborne nicotine and cotinine

  15. Waste Workers’ Exposure to Airborne Fungal and Bacterial Species in the Truck Cab and During Waste Collection

    PubMed Central

    Madsen, Anne Mette; Alwan, Taif; Ørberg, Anders; Uhrbrand, Katrine; Jørgensen, Marie Birk

    2016-01-01

    A large number of people work with garbage collection, and exposure to microorganisms is considered an occupational health problem. However, knowledge on microbial exposure at species level is limited. The aim of the study was to achieve knowledge on waste collectors’ exposure to airborne inhalable fungal and bacterial species during waste collection with focus on the transport of airborne microorganisms into the truck cab. Airborne microorganisms were collected with samplers mounted in the truck cab, on the workers’ clothes, and outdoors. Fungal and bacterial species were quantified and identified. The study showed that the workers were exposed to between 112 and 4.8×104 bacteria m−3 air and 326 and 4.6×104 fungi m−3 air. The personal exposures to bacteria and fungi were significantly higher than the concentrations measured in the truck cabs and in the outdoor references. On average, the fungal and bacterial concentrations in truck cabs were 111 and 7.7 times higher than outdoor reference measurements. In total, 23 fungal and 38 bacterial species were found and identified. Most fungal species belonged to the genus Penicillium and in total 11 Penicillium species were found. Identical fungal species were often found both in a personal sample and in the same person’s truck cab, but concentrations were on average 27 times higher in personal samples. Concentrations of fungal and bacterial species found only in the personal samples were lower than concentrations of species also found in truck cabs. Skin-related bacteria constituted a large fraction of bacterial isolates found in personal and truck cab samples. In total, six Staphylococcus species were found. In outdoor samples, no skin-related bacteria were found. On average, concentrations of bacterial species found both in the truck cab and personal samples were 77 times higher in personal samples than in truck cab samples. In conclusion, high concentrations of fungi were found in truck cabs, but the

  16. Exposure to airborne asbestos during removal and installation of gaskets and packings: a review of published and unpublished studies.

    PubMed

    Madl, Amy K; Clark, Katherine; Paustenbach, Dennis J

    2007-01-01

    In recent years, questions have been raised about the health risks to persons who have been occupationally exposed to asbestos-containing gaskets and packing materials used in pipes, valves, and machinery (pumps, autos, etc.). Up until the late 1970s, these materials were widely used throughout industrial and maritime operations, refineries, chemical plants, naval ships, and energy plants. Seven simulation studies and four work-site industrial hygiene studies of industrial and maritime settings involving the collection of more than 300 air samples were evaluated to determine the likely airborne fiber concentrations to which a worker may have been exposed while working with encapsulated asbestos-containing gaskets and packing materials. Each study was evaluated for the representativeness of work practices, analytical methods, sample size, and potential for asbestos contamination (e.g., insulation on valves or pipes used in the study). Specific activities evaluated included the removal and installation of gaskets and packings, flange cleaning, and gasket formation. In all but one of the studies relating to the replacement of gaskets and packing using hand-held tools, the short-term average exposures were less than the current 30-min OSHA excursion limit of 1 fiber per cubic centimeter (f/cc) and all of the long-term average exposures were less than the current 8-h permissible exposure limit time-weighted average (PEL-TWA) of 0.1 f/cc. The weight of evidence indicates that the use of hand tools and hand-operated power tools to remove or install gaskets or packing as performed by pipefitters or other tradesmen in nearly all plausible situations would not have produced airborne concentrations in excess of contemporaneous regulatory levels.

  17. Imaging Phenotype of Occupational Endotoxin-Related Lung Function Decline

    PubMed Central

    Lai, Peggy S.; Hang, Jing-qing; Zhang, Feng-ying; Sun, J.; Zheng, Bu-Yong; Su, Li; Washko, George R.; Christiani, David C.

    2016-01-01

    Background: Although occupational exposures contribute to a significant proportion of obstructive lung disease, the phenotype of obstructive lung disease associated with work-related organic dust exposure independent of smoking remains poorly defined. Objective: We identified the relative contributions of smoking and occupational endotoxin exposure to parenchymal and airway remodeling as defined by quantitative computed tomography (CT). Methods: The Shanghai Textile Worker Study is a longitudinal study of endotoxin-exposed cotton workers and endotoxin-unexposed silk workers that was initiated in 1981. Spirometry, occupational endotoxin exposure, and smoking habits were assessed at 5-year intervals. High-resolution computed tomography (CT) was performed in 464 retired workers in 2011, along with quantitative lung densitometric and airway analysis. Results: Significant differences in all CT measures were noted across exposure groups. Occupational endotoxin exposure was associated with a decrease (–1.3%) in percent emphysema (LAAI-950), a 3.3-Hounsfield unit increase in 15th percentile density, an 18.1-g increase in lung mass, and a 2.3% increase in wall area percent. Current but not former smoking was associated with a similar CT phenotype. Changes in LAAI-950 were highly correlated with 15th percentile density (correlation –1.0). Lung mass was the only measure associated with forced expiratory volume in 1 sec (FEV1) decline, with each 10-g increase in lung mass associated with an additional loss (–6.1 mL) of FEV1 (p = 0.001) between 1981 and 2011. Conclusions: There are many similarities between the effects of occupational endotoxin exposure and those of tobacco smoke exposure on lung parenchyma and airway remodeling. The effects of occupational endotoxin exposure appear to persist even after the cessation of exposure. LAAI-950 may not be a reliable indicator of emphysema in subjects without spirometric impairment. Lung mass is a CT-based biomarker of

  18. Airborne exposure to trihalomethanes from tap water in homes with refrigeration-type and evaporative cooling systems.

    PubMed

    Kerger, Brent D; Suder, David R; Schmidt, Chuck E; Paustenbach, Dennis J

    2005-03-26

    This study evaluates airborne concentrations of common trihalomethane compounds (THM) in selected living spaces of homes supplied with chlorinated tap water containing >85 ppb total THM. Three small homes in an arid urban area were selected, each having three bedrooms, a full bath, and approximately 1000 square feet; two homes had standard (refrigeration-type) central air conditioning and the third had a central evaporative cooling system ("swamp cooler"). A high-end water-use pattern was used at each home in this exposure simulation. THM were concurrently measured on 4 separate test days in tap water and air in the bathroom, living room, the bedroom closest to the bathroom, and outside using Summa canisters. Chloroform (trichloromethane, TCM), bromodichloromethane (BDCM), and dibromochloromethane (DBCM) concentrations were quantified using U.S. EPA Method TO-14. The apparent volatilization fraction consistently followed the order: TCM > BDCM > DBCM. Relatively low airborne THM concentrations (similar to outdoors) were found in the living room and bedroom samples for the home with evaporative cooling, while the refrigeration-cooled homes showed significantly higher THM levels (three- to fourfold). This differential remained after normalizing the air concentrations based on estimated THM throughput or water concentrations. These findings indicate that, despite higher throughput of THM-containing water in homes using evaporative coolers, the higher air exchange rates associated with these systems rapidly clears THM to levels similar to ambient outdoor concentrations.

  19. Within-Home versus Between-Home Variability of House Dust Endotoxin in a Birth Cohort

    PubMed Central

    Abraham, Joseph H.; Gold, Diane R.; Dockery, Douglas W.; Ryan, Louise; Park, Ju-Hyeong; Milton, Donald K.

    2005-01-01

    Endotoxin exposure has been proposed as an environmental determinant of allergen responses in children. To better understand the implications of using a single measurement of house dust endotoxin to characterize exposure in the first year of life, we evaluated room-specific within-home and between-home variability in dust endotoxin obtained from 470 households in Boston, Massachusetts. Homes were sampled up to two times over 5–11 months. We analyzed 1,287 dust samples from the kitchen, family room, and baby’s bedroom for endotoxin. We fit a mixed-effects model to estimate mean levels and the variation of endotoxin between homes, between rooms, and between sampling times. Endotoxin ranged from 2 to 1,945 units per milligram of dust. Levels were highest during summer and lowest in the winter. Mean endotoxin levels varied significantly from room to room. Cross-sectionally, endotoxin was moderately correlated between family room and bedroom floor (r = 0.30), between family room and kitchen (r = 0.32), and between kitchen and bedroom (r = 0.42). Adjusting for season, the correlation of endotoxin levels within homes over time was 0.65 for both the bedroom and kitchen and 0.54 for the family room. The temporal within-home variance of endotoxin was lowest for bedroom floor samples and highest for kitchen samples. Between-home variance was lowest in the family room and highest for kitchen samples. Adjusting for season, within-home variation was less than between-home variation for all three rooms. These results suggest that room-to-room and home-to-home differences in endotoxin influence the total variability more than factors affecting endotoxin levels within a room over time. PMID:16263505

  20. Anti-endotoxin vaccines

    PubMed Central

    Cross, Alan S

    2014-01-01

    Gram-negative bacterial (GNB) infections are a leading cause of serious infections both in hospitals and the community. The mortality remains high despite potent antimicrobials and modern supportive care. In the last decade invasive GNB have become increasingly resistant to commonly used antibiotics, and attempts to intervene with novel biological therapies have been unsuccessful. Earlier studies with antibodies directed against a highly conserved core region in the GNB lipopolysaccharide (LPS, or endotoxin) suggested that this approach may have therapeutic benefit, and led to the development of a subunit vaccine that has progressed to phase 1 clinical testing. Since only a few serogroups of GNB cause bacteremia, O-specific vaccines had been developed, but these were not deployed because of the availability of other therapeutic options at the time. Given the likelihood that new antibiotics will not be soon available, the development of vaccines and antibodies directed against endotoxin, both O and core antigens, deserves a “second look”. PMID:23974910

  1. Pavlovian conditioning of endotoxin-tolerance in rats.

    PubMed

    Oberbeck, Reiner; Kromm, Alexander; Exton, Michael S; Schade, Ullrich; Schedlowski, Manfred

    2003-02-01

    The most fascinating example of the bi-directional interaction between the central nervous system (CNS) and immune system is the behavioral conditioning of immune functions. We therefore investigated the behavioral conditioning of lipopolysaccharide (LPS)-induced endotoxin tolerance using the taste aversion paradigm. The conditioned stimulus (CS) saccharin was paired with the unconditioned stimulus (UCS) LPS over a five (CONDl) or four (COND2) days learning trial. Controls received drinking water with (SHAM) or without (UNT) LPS. Endotoxin tolerance was tested by determination of LPS-induced tumor necrosis factor (TNF)-alpha release. After the avoidance of the induced endotoxin-tolerance the CS saccharin was re-presented in all experimental groups. A the end of the re-exposure period a complete endotoxin tolerance was noticed in the CONDl- and COND2-group. In contrast, no effect of saccharin administration was observed in the SHAM- or UNT-group. Our data demonstrate for the first time the behavioral conditioning of endotoxin tolerance. Furthermore, these results contribute new aspects to the mechanisms underlying the development and modulation of endotoxin tolerance.

  2. Environmental Inequality in Exposures to Airborne Particulate Matter Components in the United States

    PubMed Central

    Ebisu, Keita

    2012-01-01

    Background: Growing evidence indicates that toxicity of fine particulate matter ≤ 2.5 μm in diameter (PM2.5) differs by chemical component. Exposure to components may differ by population. Objectives: We investigated whether exposures to PM2.5 components differ by race/ethnicity, age, and socioeconomic status (SES). Methods: Long-term exposures (2000 through 2006) were estimated for 215 U.S. census tracts for PM2.5 and for 14 PM2.5 components. Population-weighted exposures were combined to generate overall estimated exposures by race/ethnicity, education, poverty status, employment, age, and earnings. We compared population characteristics for tracts with and without PM2.5 component monitors. Results: Larger disparities in estimated exposures were observed for components than for PM2.5 total mass. For race/ethnicity, whites generally had the lowest exposures. Non-Hispanic blacks had higher exposures than did whites for 13 of the 14 components. Hispanics generally had the highest exposures (e.g., 152% higher than whites for chlorine, 94% higher for aluminum). Young persons (0–19 years of age) had levels as high as or higher than other ages for all exposures except sulfate. Persons with lower SES had higher estimated exposures, with some exceptions. For example, a 10% increase in the proportion unemployed was associated with a 20.0% increase in vanadium and an 18.3% increase in elemental carbon. Census tracts with monitors had more non-Hispanic blacks, lower education and earnings, and higher unemployment and poverty than did tracts without monitors. Conclusions: Exposures to PM2.5 components differed by race/ethnicity, age, and SES. If some components are more toxic than others, certain populations are likely to suffer higher health burdens. Demographics differed between populations covered and not covered by monitors. PMID:22889745

  3. Effects on health of non-occupational exposure to airborne mineral fibres.

    PubMed

    Gardner, M J; Saracci, R

    1989-01-01

    The most prominent potential marker of disease-related non-occupational exposure to mineral fibres is mesothelioma. Although many cases of mesothelioma have resulted from occupational exposure to asbestos, some have been associated with para-occupational domestic and/or neighbourhood exposure and have been reported in case series, case-control studies and a cohort study among non-occupationally exposed subjects. However, little information is available on mesothelioma as a direct consequence of general environmental asbestos exposure. Such cases of mesothelioma related to non-occupational exposure to asbestos as have occurred to date are likely to have resulted from past exposures much higher than those prevailing at the present time (in the developed countries); numbers will therefore probably decrease in the future. Very high rates of mesothelioma have been reported as a result of exposure to erionite. No studies are available on the effects of non-occupational exposure to man-made mineral fibres but, among occupationally exposed workers, a risk of mesothelioma is not apparent. There are suggestions of raised lung cancer rates among household contacts of asbestos workers and among individuals exposed to erionite. Non-malignant parenchymal and pleural abnormalities have been observed in subjects exposed non-occupationally to asbestos and erionite, but these are not necessarily associated with malignant lesions. Quantitative risk estimates of adverse effects on health have not been derived from these studies, essentially because of the absence of fibre exposure measurements.

  4. Placental mitochondrial methylation and exposure to airborne particulate matter in the early life environment: An ENVIRONAGE birth cohort study

    PubMed Central

    Janssen, Bram G; Byun, Hyang-Min; Gyselaers, Wilfried; Lefebvre, Wouter; Baccarelli, Andrea A; Nawrot, Tim S

    2015-01-01

    Most research to date has focused on epigenetic modifications in the nuclear genome, with little attention devoted to mitochondrial DNA (mtDNA). Placental mtDNA content has been shown to respond to environmental exposures that induce oxidative stress, including airborne particulate matter (PM). Damaged or non-functioning mitochondria are specifically degraded through mitophagy, exemplified by lower mtDNA content, and could be primed by epigenetic modifications in the mtDNA. We studied placental mtDNA methylation in the context of the early life exposome. We investigated placental tissue from 381 mother-newborn pairs that were enrolled in the ENVIRONAGE birth cohort. We determined mtDNA methylation by bisulfite-pyrosequencing in 2 regions, i.e., the D-loop control region and 12S rRNA (MT-RNR1), and measured mtDNA content by qPCR. PM2.5 exposure was calculated for each participant's home address using a dispersion model. An interquartile range (IQR) increment in PM2.5 exposure over the entire pregnancy was positively associated with mtDNA methylation (MT-RNR1: +0.91%, P = 0.01 and D-loop: +0.21%, P = 0.05) and inversely associated with mtDNA content (relative change of −15.60%, P = 0.001) in placental tissue. mtDNA methylation was estimated to mediate 54% [P = 0.01 (MT-RNR1)] and 27% [P = 0.06 (D-loop)] of the inverse association between PM2.5 exposure and mtDNA content. This study provides new insight into the mechanisms of altered mitochondrial function in the early life environment. Epigenetic modifications in the mitochondrial genome, especially in the MT-RNR1 region, substantially mediate the association between PM2.5 exposure during gestation and placental mtDNA content, which could reflect signs of mitophagy and mitochondrial death. PMID:25996590

  5. Association between airborne PM2.5 chemical constituents and birth weight—implication of buffer exposure assignment

    NASA Astrophysics Data System (ADS)

    Ebisu, Keita; Belanger, Kathleen; Bell, Michelle L.

    2014-08-01

    Several papers reported associations between airborne fine particulate matter (PM2.5) and birth weight, though findings are inconsistent across studies. Conflicting results might be due to (1) different PM2.5 chemical structure across locations, and (2) various exposure assignment methods across studies even among the studies that use ambient monitors to assess exposure. We investigated associations between birth weight and PM2.5 chemical constituents, considering issues arising from choice of buffer size (i.e. distance between residence and pollution monitor). We estimated the association between each pollutant and term birth weight applying buffers of 5 to 30 km in Connecticut (2000-2006), in the New England region of the USA. We also investigated the implication of the choice of buffer size in relation to population characteristics, such as socioeconomic status. Results indicate that some PM2.5 chemical constituents, such as nitrate, are associated with lower birth weight and appear more harmful than other constituents. However, associations vary with buffer size and the implications of different buffer sizes may differ by pollutant. A homogeneous pollutant level within a certain distance is a common assumption in many environmental epidemiology studies, but the validity of this assumption may vary by pollutant. Furthermore, we found that areas close to monitors reflect more minority and lower socio-economic populations, which implies that different exposure approaches may result in different types of study populations. Our findings demonstrate that choosing an exposure method involves key tradeoffs of the impacts of exposure misclassification, sample size, and population characteristics.

  6. Placental mitochondrial methylation and exposure to airborne particulate matter in the early life environment: An ENVIRONAGE birth cohort study.

    PubMed

    Janssen, Bram G; Byun, Hyang-Min; Gyselaers, Wilfried; Lefebvre, Wouter; Baccarelli, Andrea A; Nawrot, Tim S

    2015-01-01

    Most research to date has focused on epigenetic modifications in the nuclear genome, with little attention devoted to mitochondrial DNA (mtDNA). Placental mtDNA content has been shown to respond to environmental exposures that induce oxidative stress, including airborne particulate matter (PM). Damaged or non-functioning mitochondria are specifically degraded through mitophagy, exemplified by lower mtDNA content, and could be primed by epigenetic modifications in the mtDNA. We studied placental mtDNA methylation in the context of the early life exposome. We investigated placental tissue from 381 mother-newborn pairs that were enrolled in the ENVIRONAGE birth cohort. We determined mtDNA methylation by bisulfite-pyrosequencing in 2 regions, i.e., the D-loop control region and 12S rRNA (MT-RNR1), and measured mtDNA content by qPCR. PM2.5 exposure was calculated for each participant's home address using a dispersion model. An interquartile range (IQR) increment in PM2.5 exposure over the entire pregnancy was positively associated with mtDNA methylation (MT-RNR1: +0.91%, P = 0.01 and D-loop: +0.21%, P = 0.05) and inversely associated with mtDNA content (relative change of -15.60%, P = 0.001) in placental tissue. mtDNA methylation was estimated to mediate 54% [P = 0.01 (MT-RNR1)] and 27% [P = 0.06 (D-loop)] of the inverse association between PM2.5 exposure and mtDNA content. This study provides new insight into the mechanisms of altered mitochondrial function in the early life environment. Epigenetic modifications in the mitochondrial genome, especially in the MT-RNR1 region, substantially mediate the association between PM2.5 exposure during gestation and placental mtDNA content, which could reflect signs of mitophagy and mitochondrial death. PMID:25996590

  7. Occupational exposure to airborne nanomaterials: An assessment of worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fab and subfab.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2016-09-01

    This occupational exposure assessment study characterized potential inhalation exposures of workers to engineered nanomaterials associated with chemical mechanical planarization wafer polishing processes in a semiconductor research and development facility. Air sampling methodology was designed to capture airborne metal oxide nanoparticles for characterization. The research team obtained air samples in the fab and subfab areas using a combination of filter-based capture methods to determine particle morphology and elemental composition and real-time direct-reading instruments to determine airborne particle counts. Filter-based samples were analyzed by electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling was conducted during worker tasks associated with preventive maintenance and quality control that were identified as having medium to high potential for inhalation exposure based on qualitative assessments. For each sampling event, data was collected for comparison between the background, task area, and personal breathing zone. Sampling conducted over nine months included five discrete sampling series events in coordination with on-site employees under real working conditions. The number of filter-based samples captured was: eight from worker personal breathing zones; seven from task areas; and five from backgrounds. A complementary suite of direct-reading instruments collected data for seven sample collection periods in the task area and six in the background. Engineered nanomaterials of interest (Si, Al, Ce) were identified in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100-500 nm). Particle counts showed an increase in number concentration above background during a subset of the job tasks, but particle counts in the task areas were otherwise not significantly higher than background. Additional data is needed to

  8. Occupational exposure to airborne nanomaterials: An assessment of worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fab and subfab.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2016-09-01

    This occupational exposure assessment study characterized potential inhalation exposures of workers to engineered nanomaterials associated with chemical mechanical planarization wafer polishing processes in a semiconductor research and development facility. Air sampling methodology was designed to capture airborne metal oxide nanoparticles for characterization. The research team obtained air samples in the fab and subfab areas using a combination of filter-based capture methods to determine particle morphology and elemental composition and real-time direct-reading instruments to determine airborne particle counts. Filter-based samples were analyzed by electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling was conducted during worker tasks associated with preventive maintenance and quality control that were identified as having medium to high potential for inhalation exposure based on qualitative assessments. For each sampling event, data was collected for comparison between the background, task area, and personal breathing zone. Sampling conducted over nine months included five discrete sampling series events in coordination with on-site employees under real working conditions. The number of filter-based samples captured was: eight from worker personal breathing zones; seven from task areas; and five from backgrounds. A complementary suite of direct-reading instruments collected data for seven sample collection periods in the task area and six in the background. Engineered nanomaterials of interest (Si, Al, Ce) were identified in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100-500 nm). Particle counts showed an increase in number concentration above background during a subset of the job tasks, but particle counts in the task areas were otherwise not significantly higher than background. Additional data is needed to

  9. Cow allergen (Bos d2) and endotoxin concentrations are higher in the settled dust of homes proximate to industrial-scale dairy operations

    PubMed Central

    Williams, D' Ann L; McCormack, Meredith C; Matsui, Elizabeth C; Diette, Gregory B; McKenzie, Shawn E; Geyh, Alison S; Breysse, Patrick N

    2016-01-01

    Airborne contaminants produced by industrial agricultural facilities contain chemical and biological compounds that can impact the health of residents living in close proximity. Settled dust can be a reservoir for these contaminants and can influence long-term exposures. In this study, we sampled the indoor- and outdoor-settled dust from 40 homes that varied in proximity to industrial-scale dairies (ISD; industrial-scale dairy, a term used in this paper to describe a large dairy farm and adjacent waste sprayfields, concentrated animal feeding operation or animal feeding operation, that uses industrial processes) in the Yakima Valley, Washington. We analyzed settled dust samples for cow allergen (Bos d2, a cow allergen associated with dander, hair, sweat and urine, it is a member of the lipocalin family of allergens associated with mammals), mouse allergen (Mus m1; major mouse allergen, a mouse urinary allergen, in the lipocalin family), dust mite allergens (Der p1 (Dermatophagoides pteronissinus 1) and Der f1 (Dermatophagoides farinae 1)), and endotoxin (a component of the cell walls of gram negative bacteria, lipopolysaccharide, which can be found in air and dust and can produce a strong inflammatory response). A concentration gradient was observed for Bos d2 and endotoxin measured in outdoor-settled dust samples based on proximity to ISD. Indoor-settled dust concentrations of Bos d2 and endotoxin were also highest in proximal homes. While the associated health effects of exposure to cow allergen in settled dust is unknown, endotoxin at concentrations observed in these proximal homes (100 EU/mg) has been associated with increased negative respiratory health effects. These findings document that biological contaminants emitted from ISDs are elevated in indoor- and outdoor-settled dust samples at homes close to these facilities and extend to as much as three miles (4.8 km) away. PMID:25138294

  10. Exposure to bioaerosols during the growth season of tomatoes in an organic greenhouse using Supresivit (Trichoderma harzianum) and Mycostop (Streptomyces griseoviridis).

    PubMed

    Hansen, Vinni Mona; Winding, Anne; Madsen, Anne Mette

    2010-09-01

    In working environments, especially in confined spaces like greenhouses, elevated concentrations of airborne microorganisms may become a problem for workers' health. Additionally, the use of microbial pest control agents (MPCAs) may increase exposure to microorganisms. The aim of this study was to investigate tomato growers' exposure to naturally occurring bioaerosol components [dust, bacteria, fungi, actinomycetes, (1-->3)-beta-D-glucans, and endotoxin] and MPCAs applied by drip irrigation. Airborne dust was collected with filter samplers and analyzed for microorganisms by plate counts and total counts using a microscope. Analysis of (1-->3)-beta-D-glucan and endotoxin content was performed by kinetic, chromatic Limulus amoebocyte lysate tests. The fungal strain (Trichoderma harzianum) from the biocontrol product Supresivit was identified by PCR analysis. Measurements were performed on the day of drip irrigation and 1 week, 1 month, and 3 months after the irrigation. T. harzianum from Supresivit could be detected only on the day of treatment. Streptomyces griseoviridis, an applied MPCA, was not detected in the air during this investigation. We found that bioaerosol exposure increases during the growth season and that exposure to fungi, bacteria, and endotoxin can reach levels during the harvest period that may cause respiratory symptoms in growers. The collected data indicate that MPCAs applied by drip irrigation do not become airborne later in the season.

  11. Stress-Derived Corticotropin Releasing Factor Breaches Epithelial Endotoxin Tolerance

    PubMed Central

    Yu, Yong; Geng, Xiao-Rui; Yang, Gui; Liu, Zhi-Gang; Zheng, Peng-Yuan; Yang, Ping-Chang

    2013-01-01

    Background and aims Loss of the endotoxin tolerance of intestinal epithelium contributes to a number of intestinal diseases. The etiology is not clear. Psychological stress is proposed to compromise the intestinal barrier function. The present study aims to elucidate the role of the stress-derived corticotropin releasing factor (CRF) in breaching the established intestinal epithelial endotoxin tolerance. Methods Epithelial cells of HT-29, T84 and MDCK were exposed to lipopolysaccharide to induce the endotoxin tolerance; the cells were then stimulated with CRF. The epithelial barrier function was determined using as indicators of the endotoxin tolerant status. A water-avoid stress mouse model was employed to test the role of CRF in breaching the established endotoxin tolerance in the intestine. Results The established endotoxin tolerance in the epithelial cell monolayers was broken down by a sequent exposure to CRF and LPS manifesting a marked drop of the transepithelial resistance (TER) and an increase in the permeability to a macromolecular tracer, horseradish peroxidase (HRP). The exposure to CRF also increased the expression of Cldn2 in the epithelial cells, which could be mimicked by over expression of TLR4 in epithelial cells. Over expression of Cldn2 resulted in low TER in epithelial monolayers and high permeability to HRP. After treating mice with the 10-day chronic stress, the intestinal epithelial barrier function was markedly compromised, which could be prevented by blocking either CRF, or TLR4, or Cldn2. Conclusions Psychological stress-derived CRF can breach the established endotoxin tolerance in the intestinal mucosa. PMID:23840363

  12. Comparative modeling of exposure to airborne nanoparticles released by consumer spray products.

    PubMed

    Riebeling, Christian; Luch, Andreas; Götz, Mario Enrico

    2016-01-01

    Consumer exposure to sprays containing nano-objects is a continuing concern as a potential health hazard. One potential hazard has been formulated in the overload hypothesis. It describes a volume fraction of the macrophages that is occupied by deposited nanoparticles that leads to reduced macrophage mobility. Subsequent chronic inflammation may then lead to severe health consequences including cancer. To calculate lung deposition of spherical particles, the Multiple-Path Particle Dosimetry (MPPD) model (ARA, Albuquerque, NM) provides different kinds of lung models and age settings. Using the MPPD v 2.11 software, we modeled several consumer-related exposure scenarios. Different body orientations and age groups were investigated. Moreover, a number of materials representing different densities were used, and the exposure calculated using MPPD is compared to the hazard derived from the overload hypothesis. Conditions leading to macrophage overload were found for exposures to high particle doses for prolonged times and repeated exposure. Such conditions are unlikely in the context of regular consumer exposure. The overload hypothesis assumes the particles to be inert and biopersistent, a condition that currently lacks a clear regulatory definition and is valid only for a few selected materials. Furthermore, because of material-specific effects and the possibility of surface adsorption of hazardous chemicals, nano-objects in propellant sprays remain of concern for consumer health.

  13. Airborne Exposures to Polycyclic Aromatic Compounds Among Workers in Asphalt Roofing Manufacturing Facilities.

    PubMed

    Trumbore, David C; Osborn, Linda V; Johnson, Kathleen A; Fayerweather, William E

    2015-01-01

    We studied exposure of 151 workers to polycyclic aromatic compounds and asphalt emissions during the manufacturing of asphalt roofing products-including 64 workers from 10 asphalt plants producing oxidized, straight-run, cutback, and wax- or polymer-modified asphalts, and 87 workers from 11 roofing plants producing asphalt shingles and granulated roll roofing. The facilities were located throughout the United States and used asphalt from many refiners and crude oils. This article helps fill a gap in exposure data for asphalt roofing manufacturing workers by using a fluorescence technique that targets biologically active 4-6 ring polycyclic aromatic compounds and is strongly correlated with carcinogenic activity in animal studies. Worker exposures to polycyclic aromatic compounds were compared between manufacturing plants, at different temperatures and using different raw materials, and to important external benchmarks. High levels of fine limestone particulate in the plant air during roofing manufacturing increased polycyclic aromatic compound exposure, resulting in the hypothesis that the particulate brought adsorbed polycyclic aromatic compounds to the worker breathing zone. Elevated asphalt temperatures increased exposures during the pouring of asphalt. Co-exposures in these workplaces which act as confounders for both the measurement of total organic matter and fluorescence were detected and their influence discussed. Exposures to polycyclic aromatic compounds in asphalt roofing manufacturing facilities were lower than or similar to those reported in hot-mix paving application studies, and much below those reported in studies of hot application of built-up roofing asphalt. These relatively low exposures in manufacturing are primarily attributed to air emission controls in the facilities, and the relatively moderate temperatures, compared to built-up roofing, used in these facilities for oxidized asphalt. The exposure to polycyclic aromatic compounds was a very

  14. Endotoxin and cancer chemo-prevention.

    PubMed

    Mastrangelo, Giuseppe; Fadda, Emanuela; Cegolon, Luca

    2013-10-01

    Reduced rates of lung cancer have been observed in several occupational groups exposed to high levels of organic dusts contaminated by endotoxin. The underlying anti-neoplastic mechanism of endotoxin may be an increased secretion of endogenous anti-neoplastic mediators and activation of the toll-like receptors (TLR). A detoxified endotoxin derivative, Monophosphoryl Lipid A (MPL(®)) is marketed in Europe since 1999 as part of the adjuvant systems in allergy vaccines for treatment of allergic rhino-conjunctivitis and allergic asthma. Over 200,000 patients have used them to date (nearly 70% in Germany). Since detailed exposure (MPL(®) dose and timing of administration) and individual data are potentially available, an observational follow-up study could be conducted in Germany to investigate the protective effect of MPL(®) against cancer, comparing cancer incidence in two groups of patients with allergic rhinitis: those treated with allergoids plus MPL(®) and those treated with a vaccine including the same allergoids but not MPL(®). The protective effect of MPL(®) could be quantified in ever and never smokers. If this proposed observational study provides evidence of protective effects, MPL(®) could be immediately used as a chemo-preventive agent since it is already in use as adjuvant in human vaccines against cancer.

  15. Transcriptomic Analyses of the Biological Effects of Airborne PM2.5 Exposure on Human Bronchial Epithelial Cells

    PubMed Central

    Zhou, Zhixiang; Liu, Yanghua; Duan, Fengkui; Qin, Mengnan; Wu, Fengchang; Sheng, Wang; Yang, Lixin; Liu, Jianguo; He, Kebin

    2015-01-01

    Epidemiological studies have associated high levels of airborne particulate matter (PM) with increased respiratory diseases. In order to investigate the mechanisms of air pollution-induced lung toxicity in humans, human bronchial epithelial cells (16HBE) were exposed to various concentrations of particles smaller than 2.5 μm (PM2.5) collected from Beijing, China. After observing that PM2.5 decreased cell viability in a dose-dependent manner, we first used Illumina RNA-seq to identify genes and pathways that may contribute to PM2.5-induced toxicity to 16HBE cells. A total of 539 genes, 283 up-regulated and 256 down-regulated, were identified to be significantly differentially expressed after exposure to 25 μg/cm2 PM2.5. PM2.5 induced a large number of genes involved in responses to xenobtiotic stimuli, metabolic response, and inflammatory and immune response pathways such as MAPK signaling and cytokine-cytokine receptor interaction, which might contribute to PM2.5-related pulmonary diseases. We then confirmed our RNA-seq results by qPCR and by analysis of IL-6, CYP1A1, and IL-8 protein expression. Finally, ELISA assay demonstrated a significant association between exposure to PM2.5 and secretion of IL-6. This research provides a new insight into the mechanisms underlying PM2.5-induced respiratory diseases in Beijing. PMID:26382838

  16. Endotoxin hitchhiking on polymer nanoparticles

    NASA Astrophysics Data System (ADS)

    Donnell, Mason L.; Lyon, Andrew J.; Mormile, Melanie R.; Barua, Sutapa

    2016-07-01

    The control of microbial infections is critical for the preparation of biological media including water to prevent lethal septic shock. Sepsis is one of the leading causes of death in the United States. More than half a million patients suffer from sepsis every year. Both gram-positive and gram-negative bacteria are responsible for septic infection by the most common organisms i.e., Escherichia coli and Pseuodomonas aeruginosa. The bacterial cell membrane releases negatively charged endotoxins upon death and enzymatic destruction, which stimulate antigenic response in humans to gram-negative infections. Several methods including distillation, ethylene oxide treatment, filtration and irradiation have been employed to remove endotoxins from contaminated samples, however, the reduction efficiency remains low, and presents a challenge. Polymer nanoparticles can be used to overcome the current inability to effectively sequester endotoxins from water. This process is termed endotoxin hitchhiking. The binding of endotoxin on polymer nanoparticles via electrostatic and hydrophobic interactions offers efficient removal from water. However, the effect of polymer nanoparticles and its surface areas has not been investigated for removal of endotoxins. Poly(ε-caprolactone) (PCL) polymer was tested for its ability to effectively bind and remove endotoxins from water. By employing a simple one-step phase separation technique, we were able to synthesize PCL nanoparticles of 398.3 ± 95.13 nm size and a polydispersity index of 0.2. PCL nanoparticles showed ∼78.8% endotoxin removal efficiency, the equivalent of 3.9 × 105 endotoxin units (EU) per ml. This is 8.34-fold more effective than that reported for commercially available membranes. Transmission electron microscopic images confirmed binding of multiple endotoxins to the nanoparticle surface. The concept of using nanoparticles may be applicable not only to eliminate gram-negative bacteria, but also for any gram

  17. Endotoxin hitchhiking on polymer nanoparticles.

    PubMed

    Donnell, Mason L; Lyon, Andrew J; Mormile, Melanie R; Barua, Sutapa

    2016-07-15

    The control of microbial infections is critical for the preparation of biological media including water to prevent lethal septic shock. Sepsis is one of the leading causes of death in the United States. More than half a million patients suffer from sepsis every year. Both gram-positive and gram-negative bacteria are responsible for septic infection by the most common organisms i.e., Escherichia coli and Pseuodomonas aeruginosa. The bacterial cell membrane releases negatively charged endotoxins upon death and enzymatic destruction, which stimulate antigenic response in humans to gram-negative infections. Several methods including distillation, ethylene oxide treatment, filtration and irradiation have been employed to remove endotoxins from contaminated samples, however, the reduction efficiency remains low, and presents a challenge. Polymer nanoparticles can be used to overcome the current inability to effectively sequester endotoxins from water. This process is termed endotoxin hitchhiking. The binding of endotoxin on polymer nanoparticles via electrostatic and hydrophobic interactions offers efficient removal from water. However, the effect of polymer nanoparticles and its surface areas has not been investigated for removal of endotoxins. Poly(ε-caprolactone) (PCL) polymer was tested for its ability to effectively bind and remove endotoxins from water. By employing a simple one-step phase separation technique, we were able to synthesize PCL nanoparticles of 398.3 ± 95.13 nm size and a polydispersity index of 0.2. PCL nanoparticles showed ∼78.8% endotoxin removal efficiency, the equivalent of 3.9 × 10(5) endotoxin units (EU) per ml. This is 8.34-fold more effective than that reported for commercially available membranes. Transmission electron microscopic images confirmed binding of multiple endotoxins to the nanoparticle surface. The concept of using nanoparticles may be applicable not only to eliminate gram-negative bacteria, but also for any gram

  18. Endotoxin hitchhiking on polymer nanoparticles.

    PubMed

    Donnell, Mason L; Lyon, Andrew J; Mormile, Melanie R; Barua, Sutapa

    2016-07-15

    The control of microbial infections is critical for the preparation of biological media including water to prevent lethal septic shock. Sepsis is one of the leading causes of death in the United States. More than half a million patients suffer from sepsis every year. Both gram-positive and gram-negative bacteria are responsible for septic infection by the most common organisms i.e., Escherichia coli and Pseuodomonas aeruginosa. The bacterial cell membrane releases negatively charged endotoxins upon death and enzymatic destruction, which stimulate antigenic response in humans to gram-negative infections. Several methods including distillation, ethylene oxide treatment, filtration and irradiation have been employed to remove endotoxins from contaminated samples, however, the reduction efficiency remains low, and presents a challenge. Polymer nanoparticles can be used to overcome the current inability to effectively sequester endotoxins from water. This process is termed endotoxin hitchhiking. The binding of endotoxin on polymer nanoparticles via electrostatic and hydrophobic interactions offers efficient removal from water. However, the effect of polymer nanoparticles and its surface areas has not been investigated for removal of endotoxins. Poly(ε-caprolactone) (PCL) polymer was tested for its ability to effectively bind and remove endotoxins from water. By employing a simple one-step phase separation technique, we were able to synthesize PCL nanoparticles of 398.3 ± 95.13 nm size and a polydispersity index of 0.2. PCL nanoparticles showed ∼78.8% endotoxin removal efficiency, the equivalent of 3.9 × 10(5) endotoxin units (EU) per ml. This is 8.34-fold more effective than that reported for commercially available membranes. Transmission electron microscopic images confirmed binding of multiple endotoxins to the nanoparticle surface. The concept of using nanoparticles may be applicable not only to eliminate gram-negative bacteria, but also for any gram

  19. Exposure to airborne organophosphates originating from hydraulic and turbine oils among aviation technicians and loaders.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Thorud, Syvert; Ellingsen, Dag Gunnar; Lundanes, Elsa; Molander, Paal

    2010-12-01

    This study describes the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils, among ground personnel within the aviation industry. The OPs tri-n-butyl phosphate (TnBP), dibutyl phenyl phosphate (DBPP), triphenyl phosphate (TPP) and tricresyl phosphate (TCP) have been emphasized due to their use in such oils. Oil aerosol/vapor and total volatile organic compounds (tVOCs) in air were also determined. In total, 228 and 182 OPs and oil aerosol/vapor samples from technician and loader work tasks during work on 42 and 21 aircrafts, respectively, were collected in pairs. In general, the measured exposure levels were below the limit of quantification (LOQ) for 84%/98% (oil aerosol) and 82%/90% (TCP) of the samples collected during technician/loader work tasks. The air concentration ranges for all samples related to technician work were exposure levels measured during wheel well maintenance. For loader work the corresponding air concentration ranges were exposure levels measured during loading from jet engine aircrafts. Investigation of provoked exposure situations revealed substantially higher exposure levels of the contaminants when compared to regular conditions, illustrated by oil aerosol and TCP concentrations up to 240 and 31 mg m(-3), respectively. The tailored OP and the general oil aerosol sampling methods were compared, displaying the advantages of tailored OP sampling for such exposure assessments.

  20. Exposure to airborne organophosphates originating from hydraulic and turbine oils among aviation technicians and loaders.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Thorud, Syvert; Ellingsen, Dag Gunnar; Lundanes, Elsa; Molander, Paal

    2010-12-01

    This study describes the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils, among ground personnel within the aviation industry. The OPs tri-n-butyl phosphate (TnBP), dibutyl phenyl phosphate (DBPP), triphenyl phosphate (TPP) and tricresyl phosphate (TCP) have been emphasized due to their use in such oils. Oil aerosol/vapor and total volatile organic compounds (tVOCs) in air were also determined. In total, 228 and 182 OPs and oil aerosol/vapor samples from technician and loader work tasks during work on 42 and 21 aircrafts, respectively, were collected in pairs. In general, the measured exposure levels were below the limit of quantification (LOQ) for 84%/98% (oil aerosol) and 82%/90% (TCP) of the samples collected during technician/loader work tasks. The air concentration ranges for all samples related to technician work were exposure levels measured during wheel well maintenance. For loader work the corresponding air concentration ranges were exposure levels measured during loading from jet engine aircrafts. Investigation of provoked exposure situations revealed substantially higher exposure levels of the contaminants when compared to regular conditions, illustrated by oil aerosol and TCP concentrations up to 240 and 31 mg m(-3), respectively. The tailored OP and the general oil aerosol sampling methods were compared, displaying the advantages of tailored OP sampling for such exposure assessments. PMID:20949195

  1. Chylomicrons enhance endotoxin excretion in bile.

    PubMed Central

    Read, T E; Harris, H W; Grunfeld, C; Feingold, K R; Calhoun, M C; Kane, J P; Rapp, J H

    1993-01-01

    Chylomicrons prevent endotoxin toxicity and increase endotoxin uptake by hepatocytes. As a consequence, less endotoxin is available to activate macrophages, thereby reducing tumor necrosis factor secretion. To determine whether the chylomicron-mediated increase in hepatocellular uptake of endotoxin results in increased endotoxin excretion into bile, we examined bile after endotoxin administration. A sublethal dose (7 micrograms/kg) of 125I-endotoxin was incubated with either rat mesenteric lymph containing nascent chylomicrons (500 mg of chylomicron triglyceride per kg of body weight) or an equal volume of normal saline (controls) for 3 h and then infused into male Sprague-Dawley rats. Bile samples were collected via a common bile duct catheter for 24 h. Infusion of endotoxin incubated with chylomicrons increased biliary excretion of endotoxin by 67% at 3 h (P < or = 0.006) and by 20% at 24 h (P < or = 0.01) compared with infusion of endotoxin incubated in saline. Endotoxin activity, as measured by the Limulus assay, was not detected in the bile of test animals. However, endotoxin activity was detected after hot phenol-water extraction of bile, demonstrating that endotoxin is inactive in the presence of bile but retains bioactivity after hepatic processing. Since the majority of an intravenous endotoxin load has been shown to be cleared by the liver, acceleration of hepatocyte clearance and biliary excretion of endotoxin may represent a component of the mechanism by which chylomicrons protect against endotoxin-induced lethality. PMID:8335381

  2. Occupational Exposure to Airborne Nanomaterials: An Assessment of Worker Exposure to Aerosolized Metal Oxide Nanoparticles in Semiconductor Wastewater Treatment.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2015-01-01

    This study characterized potential inhalation exposures of workers to nanometal oxides associated with industrial wastewater treatment processes in a semiconductor research and development facility. Exposure assessment methodology was designed to capture aerosolized engineered nanomaterials associated with the chemical mechanical planarization wafer polishing process that were accessible for worker contact via inhalation in the on-site wastewater treatment facility. The research team conducted air sampling using a combination of filter-based capture methods for particle identification and characterization and real-time direct-reading instruments for semi-quantitation of particle number concentration. Filter-based samples were analyzed using electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling conducted over 14 months included 5 discrete sampling series events for 7 job tasks in coordination with on-site employees. The number of filter-based samples captured for analysis by electron microscopy was: 5 from personal breathing zone, 4 from task areas, and 3 from the background. Direct-reading instruments collected data for 5 sample collection periods in the task area and the background, and 2 extended background collection periods. Engineered nanomaterials of interest (Si, Al, Ce) were identified by electron microscopy in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100 nm-500 nm). Particle counts showed an increase in number concentration during and after selected tasks above background. While additional data is needed to support further statistical analysis and determine trends, this initial investigation suggests that nanoparticles used or generated by chemical mechanical planarization become aerosolized and may be accessible for inhalation exposures by workers in wastewater treatment facilities. Additional research is

  3. Occupational Exposure to Airborne Nanomaterials: An Assessment of Worker Exposure to Aerosolized Metal Oxide Nanoparticles in Semiconductor Wastewater Treatment.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2015-01-01

    This study characterized potential inhalation exposures of workers to nanometal oxides associated with industrial wastewater treatment processes in a semiconductor research and development facility. Exposure assessment methodology was designed to capture aerosolized engineered nanomaterials associated with the chemical mechanical planarization wafer polishing process that were accessible for worker contact via inhalation in the on-site wastewater treatment facility. The research team conducted air sampling using a combination of filter-based capture methods for particle identification and characterization and real-time direct-reading instruments for semi-quantitation of particle number concentration. Filter-based samples were analyzed using electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling conducted over 14 months included 5 discrete sampling series events for 7 job tasks in coordination with on-site employees. The number of filter-based samples captured for analysis by electron microscopy was: 5 from personal breathing zone, 4 from task areas, and 3 from the background. Direct-reading instruments collected data for 5 sample collection periods in the task area and the background, and 2 extended background collection periods. Engineered nanomaterials of interest (Si, Al, Ce) were identified by electron microscopy in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100 nm-500 nm). Particle counts showed an increase in number concentration during and after selected tasks above background. While additional data is needed to support further statistical analysis and determine trends, this initial investigation suggests that nanoparticles used or generated by chemical mechanical planarization become aerosolized and may be accessible for inhalation exposures by workers in wastewater treatment facilities. Additional research is

  4. A model of human nasal epithelial cells adapted for direct and repeated exposure to airborne pollutants.

    PubMed

    Bardet, Gaëlle; Achard, Sophie; Loret, Thomas; Desauziers, Valérie; Momas, Isabelle; Seta, Nathalie

    2014-08-17

    Airway epithelium lining the nasal cavity plays a pivotal role in respiratory tract defense and protection mechanisms. Air pollution induces alterations linked to airway diseases such as asthma. Only very few in vitro studies to date have succeeded in reproducing physiological conditions relevant to cellular type and chronic atmospheric pollution exposure. We therefore, set up an in vitro model of human Airway Epithelial Cells of Nasal origin (hAECN) close to real human cell functionality, specifically adapted to study the biological effects of exposure to indoor gaseous pollution at the environmental level. hAECN were exposed under air-liquid interface, one, two, or three-times at 24 h intervals for 1 h, to air or formaldehyde (200 μg/m(3)), an indoor air gaseous pollutant. All experiments were ended at day 4, when both cellular viability and cytokine production were assessed. Optimal adherence and confluence of cells were obtained 96 h after cell seeding onto collagen IV-precoated insert. Direct and repeated exposure to formaldehyde did not produce any cellular damage or IL-6 production change, although weak lower IL-8 production was observed only after the third exposure. Our model is significantly better than previous ones due to cell type and the repeated exposure protocol.

  5. Evaluation of exposure to airborne heavy metals at gun shooting ranges.

    PubMed

    Lach, Karel; Steer, Brian; Gorbunov, Boris; Mička, Vladimír; Muir, Robert B

    2015-04-01

    Aerosols formed during shooting events were studied with various techniques including the wide range size resolving sampling system Nano-ID(®) Select, followed by inductively coupled plasma mass spectrometry chemical analysis, scanning electron microscopy, and fast mobility particle sizing. The total lead mass aerosol concentration ranged from 2.2 to 72 µg m(-3). It was shown that the mass concentration of the most toxic compound lead is much lower than the total mass concentration. The deposition fraction in various compartments of the respiratory system was calculated using the ICRP lung deposition model. It was found that the deposition fraction in the alveolar range varies by a factor >3 for the various aerosols collected, depending on the aerosol size distribution and total aerosol concentration, demonstrating the importance of size resolved sampling in health risk evaluation. The proportion of the total mass of airborne particles deposited in the respiratory tract varies from 34 to 70%, with a median of 55.9%, suggesting the health risk based upon total mass significantly overestimates the accumulated dose and therefore the health risk. A comparison between conventional and so called 'green' ammunition confirmed significant lowering of concentrations of lead and other toxic metals like antimony in the atmosphere of indoor shooting ranges using 'green' ammunition, although higher concentrations of manganese and boron were measured. These metals are likely to be the constituents of new types of primers. They occur predominantly in the size fraction <250 nm of aerosols.

  6. Simulation tests to assess occupational exposure to airborne asbestos from artificially weathered asphalt-based roofing products.

    PubMed

    Sheehan, Patrick; Mowat, Fionna; Weidling, Ryan; Floyd, Mark

    2010-11-01

    Historically, asbestos-containing roof cements and coatings were widely used for patching and repairing leaks. Although fiber releases from these materials when newly applied have been studied, there are virtually no useful data on airborne asbestos fiber concentrations associated with the repair or removal of weathered roof coatings and cements, as most studies involve complete tear-out of old roofs, rather than only limited removal of the roof coating or cement during a repair job. This study was undertaken to estimate potential chrysotile asbestos fiber exposures specific to these types of roofing products following artificially enhanced weathering. Roof panels coated with plastic roof cement and fibered roof coating were subjected to intense solar radiation and daily simulated precipitation events for 1 year and then scraped to remove the weathered materials to assess chrysotile fiber release and potential worker exposures. Analysis of measured fiber concentrations for hand scraping of the weathered products showed 8-h time-weighted average concentrations that were well below the current Occupational Safety and Health Administration permissible exposure limit for asbestos. There was, however, visibly more dust and a few more fibers collected during the hand scraping of weathered products compared to the cured products previously tested. There was a notable difference between fibers released from weathered and cured roofing products. In weathered samples, a large fraction of chrysotile fibers contained low concentrations of or essentially no magnesium and did not meet the spectral, mineralogical, or morphological definitions of chrysotile asbestos. The extent of magnesium leaching from chrysotile fibers is of interest because several researchers have reported that magnesium-depleted chrysotile fibers are less toxic and produce fewer mesothelial tumors in animal studies than normal chrysotile fibers. PMID:20923966

  7. Detection of airborne bacteria in a duck production facility with two different personal air sampling devices for an exposure assessment.

    PubMed

    Martin, Elena; Dziurowitz, Nico; Jäckel, Udo; Schäfer, Jenny

    2015-01-01

    Prevalent airborne microorganisms are not well characterized in industrial animal production buildings with respect to their quantity or quality. To investigate the work-related microbial exposure, personal bioaerosol sampling during the whole working day is recommended. Therefore, bioaerosol sampling in a duck hatchery and a duck house with two personal air sampling devices, a filter-based PGP and a NIOSH particle size separator, was performed. Subsequent, quantitative and qualitative analyses were carried out with" culture independent methods. Total cell concentrations (TCC) determined via fluorescence microscopy showed no difference between the two devices. In average, 8 × 10(6) cells/m(3) were determined in the air of the duck hatchery and 5 × 10(7) cells/m(3) in the air of the duck house. A Generated Restriction Fragment Length Polymorphism (RFLP) pattern revealed deviant bacterial compositions comparing samples collected with both devices. Clone library analyses based on 16S rRNA gene sequence analysis from the hatchery's air showed 65% similarity between the two sampling devices. Detailed 16S rRNA gene sequence analyses showed the occurrence of bacterial species like Acinetobacter baumannii, Enterococcus faecalis, Escherichia sp., and Shigella sp.; and a group of Staphylococcus delphini, S. intermedius, and S. pseudintermedius that provided the evidence of potential exposure to risk group 2 bacteria at the hatchery workplace. Size fractionated sampling with the developed by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) device revealed that pathogenic bacteria would deposit in the inhalable, the thorax, and possibly alveolar dust fraction according to EN481. TCC analysis showed the deposition of bacterial cells in the third stage (< 1μm) at the NIOSH device which implies that bacteria can reach deep into the lungs and contaminate the alveolus after inhalation. Nevertheless, both personal sampling devices

  8. CHILDHOOD RESPIRATORY SYMPTOMS, HOSPITAL ADMISSIONS, AND LONG-TERM EXPOSURE TO AIRBORNE PARTICULATE MATTER

    EPA Science Inventory

    The effects of long-term exposure to air pollution on respiratory symptoms and respiratory hospitalization (for asthma, bronchitis or pneumonia) were assessed in a cross-sectional study of children (ages 7--11 years, N=667) living in a moderately industrialized city in Central Sl...

  9. Exposure to Airborne Polycyclic Aromatic Hydrocarbons During Pregnancy and Risk of Preterm Birth

    PubMed Central

    Padula, Amy M.; Noth, Elizabeth M.; Hammond, S. Katharine; Lurmann, Fred W.; Yang, Wei; Tager, Ira B.; Shaw, Gary M.

    2014-01-01

    Background Preterm birth is an important marker of health and has a prevalence of 12-13% in the U.S. Polycyclic aromatic hydrocarbons (PAHs) are a group of organic contaminants that form during the incomplete combustion of hydrocarbons, such as coal, diesel and gasoline. Studies suggest that exposure to PAHs during pregnancy is related to adverse birth outcomes. The aim of this study is to evaluate the association between exposure to PAHs during the pregnancy and preterm birth. Methods The study population included births from years 2001-2006 of women whose maternal residence was within 20 km of the primary monitoring site in Fresno, California. Data in the Fresno area were used to form a spatio-temporal model to assign daily exposure to PAHs with 4, 5, or 6 rings at the maternal residence throughout pregnancy of all of the births in the study area. Gestational age at birth and relevant covariates were extracted from the birth certificate. Results We found an association between PAHs during the last 6 weeks of pregnancy and birth at 20-27 weeks (OR=2.74; 95% CI: 2.24-3.34) comparing the highest quartile to the lower three. The association was consistent when each quartile was compared to the lowest (OR2nd=1.49, 95% CI: 1.08-2.06; OR3rd=2.63, 95% CI:1.93-3.59; OR4th=3.94, 95% CI:3.03-5.12). Inverse associations were also observed for exposure to PAHs during the entire pregnancy and the first trimester and birth at 28-31 weeks and 20-27 weeks. Conclusion An association between PAH exposure during the 6 weeks before delivery and early preterm birth was observed. However, the inverse association with early preterm birth offers an unclear, and potentially complex, inference of these associations. PMID:25282280

  10. Airborne toluene removal for minimizing occupational health exposure by means of a trickle-bed biofilter.

    PubMed

    Raboni, Massimo; Torretta, Vincenzo; Viotti, Paolo

    2016-06-01

    The paper presents the experimental results on a biotrickling pilot plant, with a water scrubber as pre-treatment, finalized to the treatment of an airborne toluene stream in a working place. The air stream was characterized by a very high variability of the inlet concentrations of toluene (range: 4.35-68.20 mg Nm(-3)) with an average concentrations of 16.41 mg Nm(-3). The pilot plant has proved its effectiveness in toluene removal, along a 90-day experimentation period, in steady-state conditions. The scrubbing pre-treatment has achieved an average removal efficiency of 69.9 %, but in particular it has proven its suitability in the rough removal of the toluene peak concentrations, allowing a great stability to the following biological process. The biotrickling stage has achieved an additional average removal efficiency of 75.6 %, confirming the good biodegradability of toluene. The biofilm observation by a scanning confocal laser microscope has evidenced a biofilm thickness of 650 μm fully penetrated by toluene degrading bacteria. Among the micro-population Pseudomonas putida resulted the dominant specie. This bacterium can therefore be considered the responsible for most of the toluene degradation. The whole experimented process has determined an average 92.7 % for toluene removal efficiency. This result meets the most stringent limits and recommendations for occupational safety, given by authoritative organizations in the USA and EU; it also meets the odorous threshold concentration of 11.1 mg Nm(-3).

  11. Field evaluation of endotoxin air sampling assay methods.

    PubMed

    Thorne, P S; Reynolds, S J; Milton, D K; Bloebaum, P D; Zhang, X; Whitten, P; Burmeister, L F

    1997-11-01

    This study tested the importance of filter media, extraction and assay protocol, and bioaerosol source on the determination of endotoxin under field conditions in swine and poultry confinement buildings. Multiple simultaneous air samples were collected using glass fiber (GF) and polycarbonate (PC) filters, and these were assayed using two methods in two separate laboratories: an endpoint chromogenic Limulus amebocyte lysate (LAL) assay (QCL) performed in water and a kinetic chromogenic LAL assay (KQCL) performed in buffer with resistant-parallel line estimation analysis (KLARE). In addition, two aqueous filter extraction methods were compared in the QCL assay: 120 min extraction at 22 degrees C with vigorous shaking and 30 min extraction at 68 degrees C with gentle rocking. These extraction methods yielded endotoxin activities that were not significantly different and were very highly correlated. Reproducibility of endotoxin determinations from duplicate air sampling filters was very high (Cronbach alpha all > 0.94). When analyzed by the QCL method GF filters yielded significantly higher endotoxin activity than PC filters. QCL and KLARE methods gave similar estimates for endotoxin activity from PC filters; however, GF filters analyzed by the QCL method yielded significantly higher endotoxin activity estimates, suggesting enhancement of the QCL assay or inhibition of the KLARE asay with GF filters. Correlation between QCL-GF and QCL-PC was high (r = 0.98) while that between KLARE-GF and KLARE-PC was moderate (r = 0.68). Analysis of variance demonstrated that assay methodology, filter-type, barn-type, and interactions between assay and filter-type and between assay and barn-type were important factors influencing endotoxin exposure assessment.

  12. Recommended default methodology for analysis of airborne exposures to mixtures of chemicals in emergencies.

    PubMed

    Craig, D K; Baskett, R L; Davis, J S; Dukes, L; Hansen, D J; Petrocchi, A J; Powell, T J; Sutherland, P J; Tuccinardi, T E

    1999-09-01

    Emergency planning and hazard assessment of Department of Energy (DOE) facilities require consideration of potential exposures to mixtures of chemicals released to the atmosphere. Exposure to chemical mixtures may lead to additive, synergistic, or antagonistic health effects. In the past, the consequences of exposures to each chemical have been analyzed separately. This approach may not adequately protect the health of persons exposed to mixtures. This article presents default recommendations for use in emergency management and safety analysis within the DOE complex where potential exists for releases of mixtures of chemicals. These recommendations were developed by the DOE Subcommittee on Consequence Assessment and Protective Actions (SCAPA). It is recommended that hazard indices (e.g., HIi = Ci/Limiti, where Ci is the concentration of chemical "i") be calculated for each chemical, and unless sufficient toxicological knowledge is available to indicate otherwise, that they be summed, that is, sigma i(n) = 1HIi = HI1 + HI2 + ... + HIn. A sum of 1.0 or less means the limits have not been exceeded. To facilitate application of these recommendations for analysis of exposures to specific mixtures, chemicals are classified according to their toxic consequences. This is done using health code numbers describing toxic effects by target organ for each chemical. This methodology has been applied to several potential releases of chemicals to compare the resulting hazard indices of a chemical mixture with those obtained when each chemical is treated independently. The methodology used and results obtained from analysis of one mixture are presented in this article. This article also demonstrates how health code numbers can be used to sum hazard indices only for those chemicals that have the same toxic consequence.

  13. Technical bases for plastic suit reduction factors against airborne tritium exposure

    SciTech Connect

    Edwards, T.

    1993-04-19

    Radiological Engineering was requested to provide bases for certain Tritium Stay Time Charts. These charts had evidently been developed by calculating stay times based upon unprotected exposure to HTO concentrations in air and applying correction factors according to the type of plastic suit being worn. No technical justification could be found for results given for 12 mil and 9 mil plastic suits. On the basis of available empirical data, the stay time charts were revised.

  14. Personal exposure to airborne ultrafine particles in the urban area of Milan

    NASA Astrophysics Data System (ADS)

    Cattaneo, A.; Garramone, G.; Taronna, M.; Peruzzo, C.; Cavallo, D. M.

    2009-02-01

    The relevance of health effects related to ultrafine particles (UFPs; aerodynamic diameter < 100 nm) can be better evaluated using high-resolution strategies for measuring particle number concentrations. In this study, two different portable Condensation Particle Counters (CPCs) were used to measure personal exposure to UFPs in the central area of Milan for one week period during spring, with three sampling sessions per day. Experimental data were continuously collected along an established urban pathway, moving afoot or by different private and public means of transport. Correlation analysis between data measured by two CPCs was performed and general results showed a good agreement, especially at concentrations lower than 2×105 particles /cm3. UFPs measures were divided on the basis of crossed environments or micro-environments, days of the week and day time (hours). The highest measured mean concentrations and data variability were observed during walking time and moving on motorized vehicles (bus and car), indicating that the highest exposure to UFPs can be reached near motorized traffic. The lowest exposures were observed in green areas and in office microenvironments. An appreciable difference between working and non-working days was observed. Concentration patterns and variation by days of the week and time periods appears related to time trends in traffic intensity.

  15. Total exposure to airborne particulate matter in cities: the effect of biomass combustion.

    PubMed

    Sarigiannis, Dimosthenis Α; Karakitsios, Spyros P; Kermenidou, Marianthi; Nikolaki, Spyridoula; Zikopoulos, Dimitrios; Semelidis, Stauros; Papagiannakis, Apostolos; Tzimou, Roxani

    2014-09-15

    The study deals with the seasonal variability of PM exposure and the effect that biomass combustion has upon it in the urban environment. The study is based on measurements, chemical analyses and modeling results performed in Thessaloniki (Greece). The measurements campaign included the assessment of outdoor and indoor air quality and the evaluation of biomass use for domestic heating. The outdoor measurements highlighted a significant increase of PM10 (from 30.1 to 73.1 μg/m(3)) and PM2.5 (from 19.4 to 62.7 μg/m(3)) concentrations during the transition from the warm to the cold period of the year 2012 compared to 2011. The increase in ambient air PM during the winter was attributed to the use of biomass burning for space heating. The latter was verified by the presence of levoglucosan in the PM (concentrations up to 8 μg/m(3)), especially for samples taken from the urban background site. Outdoor PM concentrations were also modeled using an artificial neural network model taking into account major meteorological parameters; the latter explained more than 90% of PM10 and PM2.5 day-to-day variability. Indoor concentrations followed a similar pattern, while in the case of fireplace use, average daily concentrations rise to 10 μg/m(3) and 14 μg/m(3) for PM2.5 and PM10 respectively. Indoor air concentrations were affected the most by the ambient air particle infiltration. Indoor air quality went down after 3h of open fire biomass combustion for space heating. Personal exposure was significantly determined by overall indoor air quality. Yet, dynamic exposure analysis revealed that peaks of intake do not correspond to peaks of ambient air PM concentrations altering thus total exposure patterns. Thus, cost-effective public health protection has to aim at reducing the exposure profile of susceptible population sub-groups combining awareness raising, emission reduction measures and financial incentives to influence the choice of space heating systems. PMID:25000575

  16. The macrophage mediates the renoprotective effects of endotoxin preconditioning.

    PubMed

    Hato, Takashi; Winfree, Seth; Kalakeche, Rabih; Dube, Shataakshi; Kumar, Rakesh; Yoshimoto, Momoko; Plotkin, Zoya; Dagher, Pierre C

    2015-06-01

    Preconditioning is a preventative approach, whereby minimized insults generate protection against subsequent larger exposures to the same or even different insults. In immune cells, endotoxin preconditioning downregulates the inflammatory response and yet, preserves the ability to contain infections. However, the protective mechanisms of preconditioning at the tissue level in organs such as the kidney remain poorly understood. Here, we show that endotoxin preconditioning confers renal epithelial protection in various models of sepsis in vivo. We also tested the hypothesis that this protection results from direct interactions between the preconditioning dose of endotoxin and the renal tubules. This hypothesis is on the basis of our previous findings that endotoxin toxicity to nonpreconditioned renal tubules was direct and independent of immune cells. Notably, we found that tubular protection after preconditioning has an absolute requirement for CD14-expressing myeloid cells and particularly, macrophages. Additionally, an intact macrophage CD14-TRIF signaling pathway was essential for tubular protection. The preconditioned state was characterized by increased macrophage number and trafficking within the kidney as well as clustering of macrophages around S1 proximal tubules. These macrophages exhibited increased M2 polarization and upregulation of redox and iron-handling molecules. In renal tubules, preconditioning prevented peroxisomal damage and abolished oxidative stress and injury to S2 and S3 tubules. In summary, these data suggest that macrophages are essential mediators of endotoxin preconditioning and required for renal tissue protection. Preconditioning is, therefore, an attractive model to investigate novel protective pathways for the prevention and treatment of sepsis.

  17. Endotoxin neutralization as a biomonitor for inflammatory bowel disease.

    PubMed

    Champion, Keith; Chiu, Laura; Ferbas, John; Pepe, Michael

    2013-01-01

    Gram-negative bacterial endotoxin is a potent immunostimulant implicated in the development and/or progression of a variety of diseases. The mammalian immune system has both innate and adaptive immune responses to neutralize endotoxin. In this study, a system was developed to monitor bacterial exposure by measuring the extent and nature of endotoxin neutralization in plasma. In control patients, females had higher levels of endotoxin neutralization than males, mirroring clinical outcomes from bacterial infection and sepsis. In addition to the total amount of neutralization, we used inactivation techniques to elucidate the nature of this activity and develop a system to compare early and late immune responses. Using this method to monitor patients with inflammatory bowel disease, we found a more robust total response that relies more on long-term, adaptive components of the immune system and less on early, innate components. Our results indicate that endotoxin neutralization is a valuable method to discern inflammatory bowel disease patients from a control population. Additionally, the nature of neutralization may be valuable in monitoring disease severity and/or the role of medication.

  18. Pantoea agglomerans: a mysterious bacterium of evil and good. Part II--Deleterious effects: Dust-borne endotoxins and allergens--focus on grain dust, other agricultural dusts and wood dust.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Skórska, Czesława; Góra-Florek, Anna; Milanowski, Janusz

    2016-01-01

    Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of P. agglomerans in grain as well as in the settled grain and flour dust was found to be high, ranging from 10(4)-10(8) CFU/g, while in the air polluted with grain or flour dust it ranged from 10(3)-10(5) CFU/m(3) and formed 73.2-96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS). The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10-50 nm that could be described as the 'endotoxin super-macromolecules'. A highly significant relationship was found (R=0.804, P=0.000927) between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS). Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA), endotoxin nanoparticles isolated in sucrose gradient (VECN), and mixture of proteins and endotoxin obtained

  19. Pantoea agglomerans: a mysterious bacterium of evil and good. Part II--Deleterious effects: Dust-borne endotoxins and allergens--focus on grain dust, other agricultural dusts and wood dust.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Skórska, Czesława; Góra-Florek, Anna; Milanowski, Janusz

    2016-01-01

    Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of P. agglomerans in grain as well as in the settled grain and flour dust was found to be high, ranging from 10(4)-10(8) CFU/g, while in the air polluted with grain or flour dust it ranged from 10(3)-10(5) CFU/m(3) and formed 73.2-96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS). The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10-50 nm that could be described as the 'endotoxin super-macromolecules'. A highly significant relationship was found (R=0.804, P=0.000927) between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS). Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA), endotoxin nanoparticles isolated in sucrose gradient (VECN), and mixture of proteins and endotoxin obtained

  20. Alcohol, intestinal bacterial growth, intestinal permeability to endotoxin, and medical consequences: summary of a symposium.

    PubMed

    Purohit, Vishnudutt; Bode, J Christian; Bode, Christiane; Brenner, David A; Choudhry, Mashkoor A; Hamilton, Frank; Kang, Y James; Keshavarzian, Ali; Rao, Radhakrishna; Sartor, R Balfour; Swanson, Christine; Turner, Jerrold R

    2008-08-01

    This report is a summary of the symposium on Alcohol, Intestinal Bacterial Growth, Intestinal Permeability to Endotoxin, and Medical Consequences, organized by National Institute on Alcohol Abuse and Alcoholism, Office of Dietary Supplements, and National Institute of Diabetes and Digestive and Kidney Diseases of National Institutes of Health in Rockville, Maryland, October 11, 2006. Alcohol exposure can promote the growth of Gram-negative bacteria in the intestine, which may result in accumulation of endotoxin. In addition, alcohol metabolism by Gram-negative bacteria and intestinal epithelial cells can result in accumulation of acetaldehyde, which in turn can increase intestinal permeability to endotoxin by increasing tyrosine phosphorylation of tight junction and adherens junction proteins. Alcohol-induced generation of nitric oxide may also contribute to increased permeability to endotoxin by reacting with tubulin, which may cause damage to microtubule cytoskeleton and subsequent disruption of intestinal barrier function. Increased intestinal permeability can lead to increased transfer of endotoxin from the intestine to the liver and general circulation where endotoxin may trigger inflammatory changes in the liver and other organs. Alcohol may also increase intestinal permeability to peptidoglycan, which can initiate inflammatory response in liver and other organs. In addition, acute alcohol exposure may potentiate the effect of burn injury on intestinal bacterial growth and permeability. Decreasing the number of Gram-negative bacteria in the intestine can result in decreased production of endotoxin as well as acetaldehyde which is expected to decrease intestinal permeability to endotoxin. In addition, intestinal permeability may be preserved by administering epidermal growth factor, l-glutamine, oats supplementation, or zinc, thereby preventing the transfer of endotoxin to the general circulation. Thus reducing the number of intestinal Gram-negative bacteria

  1. Antibiotic-induced release of endotoxin in chronically bacteriuric patients.

    PubMed Central

    Hurley, J C; Louis, W J; Tosolini, F A; Carlin, J B

    1991-01-01

    A novel in vivo model for the study of antibiotic-induced release of endotoxin from gram-negative bacteria is described. The model uses the chronically colonized urinary tracts of patients whose spinal cords have been injured. At baseline, the organisms were present in the range of 1 x 10(3) to 2 x 10(7) CFU/ml, and the concentration of endotoxin ranged from 2 x 10(-1) to 1 x 10(3) ng/ml in 44 studies. In 10 control studies, the concentration of endotoxin and the numbers of viable gram-negative bacteria over time changed by an average of less than 0.15 log10 units from the baseline values. At 2 h after antibiotic administration, the average decrease in CFU was 0.93 log10 units, and because antibiotics cause the release of endotoxin, an average increase in endotoxin concentration of 0.59 log10 units was noted in 21 studies with susceptible bacteria. Similar changes in response to antibiotic exposure were seen in studies with susceptible Pseudomonas bacteria in comparison with those seen in studies with susceptible members of the family Enterobacteriaceae. These results provide evidence that this novel model may be useful for comparing the effects of antibiotics with different modes of action, both as single agents and in combination, on the concentration of endotoxin in relation to changes in the numbers of bacteria, under conditions of bacterial replication and antibiotic exposure more closely resembling those found in vivo than is possible in other models. PMID:1804012

  2. Growth inhibitory effects of endotoxins from Bacteroides gingivalis and intermedius on human gingival fibroblasts in vitro

    SciTech Connect

    Layman, D.L.; Diedrich, D.L.

    1987-06-01

    Purified endotoxin or lipopolysaccharide from Bacteroides gingivalis and Bacteroides intermedius caused a similar dose-dependent inhibition of growth of cultured human gingival fibroblasts as determined by /sup 3/H-thymidine incorporation and direct cell count. Approximately 200 micrograms/ml endotoxin caused a 50% reduction in /sup 3/H-thymidine uptake of logarithmically growing cells. Inhibition of growth was similar in cultures of fibroblasts derived from either healthy or diseased human gingiva. When examining the change in cell number with time of exposure in culture, the rate of proliferation was significantly suppressed during the logarithmic phase of growth. However, the cells recovered so that the rate of proliferation, although reduced, was sufficient to produce a cell density similar to the control cells with prolonged culture. The endotoxins were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The profiles of the Bacteroides endotoxins were different. B. gingivalis endotoxin showed a wide range of distinct bands indicating a heterogeneous distribution of molecular species. Endotoxin from B. intermedius exhibited a few discrete low molecular weight bands, but the majority of the lipopolysaccharides electrophoresed as a diffuse band of high molecular weight material. The apparent heterogeneity of the two Bacteroides endotoxins and the similarity in growth inhibitory capacity suggest that growth inhibitory effects of these substances cannot be attributed to any polysaccharide species of endotoxin.

  3. Personal exposure to airborne particles and metals: results from the Particle TEAM study in Riverside, California.

    PubMed

    Ozkaynak, H; Xue, J; Spengler, J; Wallace, L; Pellizzari, E; Jenkins, P

    1996-01-01

    The PTEAM Study was the first large-scale probability-based study of personal exposure to particles. Sponsored by the U.S. Environmental Protection Agency (EPA) and the Air Resources Board of California, it was carried out by the Research Triangle Institute (RTI) and the Harvard University School of Public Health (HSPH). HSPH designed and constructed a 4-lpm, battery-operated personal monitor for inhalable particles (PM10) that could be worn comfortably for up to 14 hours by persons from 10 to 70 years old. The monitor was worn for two consecutive 12-hour periods (day and night) during the fall of 1990 by 178 participants representing 139,000 nonsmoking residents of Riverside, California. Nearly identical monitors were employed to collect concurrent indoor and outdoor samples. The monitors were equipped with a different sampling nozzle to collect fine particles (PM2.5). Population-weighted daytime personal PM10 exposures averaged 150 +/- 9 (SE) micrograms/m3, compared to concurrent indoor and outdoor concentrations of 95 +/- 6 micrograms/m3. This suggested the existence of excess mass near the person, a "personal cloud" that appeared related to personal activities. Fourteen of 15 prevalent elements also were evaluated in the personal samples. The two major indoor sources of indoor particles were smoking and cooking; even in these homes, however, more than half of the indoor particles came from outdoors, and a substantial portion of the indoor particles were of undetermined indoor origin. Outdoor concentrations near the homes were well correlated with outdoor concentrations at the central site, supporting the idea of using the central site as an indicator of of ambient concentrations over a wider area. Indoor concentrations were only weakly correlated with outdoor concentrations, however, and personal exposures were even more poorly correlated with outdoor concentrations. Elemental profiles were obtained for environmental tobacco smoke (ETS) (major contributions

  4. Vertical and horizontal variability in airborne nanoparticles and their exposure around signalised traffic intersections.

    PubMed

    Goel, Anju; Kumar, Prashant

    2016-07-01

    We measured size-resolved PNCs in the 5-560 nm range at two different types (4- and 3-way) of TIs in Guildford (Surrey, UK) at fixed sites (∼1.5 m above the road level), sequentially at 4 different heights (1, 1.5, 2.5 and 4.7 m), and along the road at five different distances (10, 20, 30, 45 and 60 m). The aims were to: (i) assess the differences in PNCs measured at studied TIs, (ii) identify the best fit probability distribution curves for the PNCs, (iii) determine vertical and horizontal decay profiles of PNCs, (iv) estimate particle number emission factors (PNEFs) under congested and free-flow traffic conditions, and (v) quantify the pedestrian exposure in terms of respiratory deposition dose (RDD) rates at the TIs. Daily averaged particle number distributions at TIs reflected the effect of fresh emissions with peaks at 5.6, 10 and 56 nm. Despite the relatively high traffic volume at 3-way TI, average PNCs at 4-way TI were about twice as high as at 3-way TI, indicating less favourable dispersion conditions. Generalised extreme value distribution fitted well to PNC data at both TIs. Vertical PNC profiles followed an exponential decay, which was much sharper at 4-way TI than at 3-way TI, suggesting ∼40% less exposure for people at first floor (4.7 m) to those at ground floor around 4-way TI. Vertical profiles indicated much sharper (∼132-times larger) decay than in horizontal direction, due to close vicinity of road vehicles during the along-road measurements. Over an order of magnitude higher PNEFs were found during congested, compared with free-flow, conditions due to frequent changes in traffic speed. Average RDD rate at 4-way TI during congested conditions were up to 14-times higher than those at 3-way TI (0.4 × 10(11) h(-1)). Findings of this study are a step forward to understand exposure at and around the TIs.

  5. Exposure to airborne isocyanates and other thermal degradation products at polyurethane-processing workplaces.

    PubMed

    Henriks-Eckerman, Maj-Len; Välimaa, Jarmo; Rosenberg, Christina; Peltonen, Kimmo; Engström, Kerstin

    2002-10-01

    The thermal degradation products of polyurethanes (PURs) and exposure to isocyanates were studied by stationary and personal measurements in five different occupational environments. Isocyanates were collected on glass fibre filters impregnated with 1-(2-methoxyphenyl)piperazine (2MP) and in impingers containing n-dibutylamine (DBA) in toluene. connected to a glass fibre postfilter. The derivatives formed were analysed by liquid chromatography: 2MP derivatives with UV and electrochemical detection and DBA derivatives with mass spectrometric detection. The release of aldehydes and other volatile organic compounds into the air was also studied. In a comparison of the two sampling methods, the 2MP method yielded about 20% lower concentrations for 4,4'-methylenediphenyl diisocyanate (MDI) than did the DBA method. In car repair shops, the median concentration of diisocyanates (given as NCO groups) in the breathing zone was 1.1 microg NCO m(-3) during grinding and 0.3 microg NCO m(-3) during welding, with highest concentrations of 1.7 and 16 pg NCO m(-3), respectively. High concentrations of MDI, up to 25 and 19 microg NCO m(-3), respectively, were also measured in the breathing zone during welding of district heating pipes and turning of a PUR-coated metal cylinder. During installation of PUR-coated floor covering, small amounts of aliphatic diisocyanates were detected in the air. A small-molecular monoisocyanate, methyl isocyanate, and isocyanic acid were detected only during welding and turning operations. The diisocyanate concentrations were in general higher near the emission source than in the workers' breathing zone. A sampling strategy to evaluate the risk of exposure to isocyanates is presented.

  6. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    PubMed

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments.

  7. Endotoxin and β-(1,3)-glucan levels in automobiles: a pilot study.

    PubMed

    Wu, Francis Fu-Sheng; Wu, Mei-Wen; Chang, Chin-Fu; Lai, Shu-Mei; Pierse, Nevil; Crane, Julian; Siebers, Rob

    2010-01-01

    Exposure to bacterial endotoxin and fungal β-(1,3)-glucan in the indoor environment can induce respiratory symptoms. Automobiles are an exposure source of allergens but it is not known if, and how much exposure there is to endotoxin and fungal β-(1,3)-glucan. The objective of the study was to determine whether automobiles are a potential source of exposure to these microbial products. Dust was sampled from the passenger seats of 40 automobiles. Specific Limulus amoebocyte kinetic assays were used to measure endotoxin and β-(1,3)-glucan, respectively. Endotoxin and β-(1,3)-glucan was detected in all samples ranging from 19.9-247.0 EU/mg and 1.6-59.8 μg/g, respectively. There were no significant differences in endotoxin levels between automobiles of smokers and non-smokers, but β-(1,3)-glucan levels were about two-fold higher in the automobiles of non-smokers. In conclusion, endotoxin and β-(1,3)-glucan exposure in automobiles at levels found in our study may be of importance for asthmatics.

  8. SUBCHRONIC ENDOTOXIN INHALATION CAUSES CHRONIC AIRWAY DISEASE IN ENDOTOXIN-SENSITIVE BUT NOT ENDOTOXIN-RESISTANT MICE

    EPA Science Inventory

    SUBCHRONIC ENDOTOXIN INHALATION CAUSES CHRONIC AIRWAY DISEASE IN ENDOTOXIN-SENSITIVE BUT NOT ENDOTOXIN-RESISTANT MICE. D. M. Brass, J. D. Savov, *S. H. Gavett, ?C. George, D. A. Schwartz. Duke Univ Medical Center Durham, NC, *U.S. E.P.A. Research Triangle Park, NC, ?Univ of Iowa,...

  9. Temporal and Spatial Patterns of Ambient Endotoxin Concentrations in Fresno, California

    PubMed Central

    Tager, Ira B.; Lurmann, Frederick W.; Haight, Thaddeus; Alcorn, Siana; Penfold, Bryan; Hammond, S. Katharine

    2010-01-01

    Background Endotoxins are found in indoor dust generated by human activity and pets, in soil, and adsorbed onto the surfaces of ambient combustion particles. Endotoxin concentrations have been associated with respiratory symptoms and the risk of atopy and asthma in children. Objective We characterized the temporal and spatial variability of ambient endotoxin in Fresno/Clovis, California, located in California’s Central Valley, to identify correlates and potential predictors of ambient endotoxin concentrations in a cohort of children with asthma [Fresno Asthmatic Children’s Environment Study (FACES)]. Methods Between May 2001 and October 2004, daily ambient endotoxin and air pollutants were collected at the central ambient monitoring site of the California Air Resources Board in Fresno and, for shorter time periods, at 10 schools and indoors and outdoors at 84 residences in the community. Analyses were restricted to May–October, the dry months during which endotoxin concentrations are highest. Results Daily endotoxin concentration patterns were determined mainly by meteorologic factors, particularly the degree of air stagnation. Overall concentrations were lowest in areas distant from agricultural activities. Highest concentrations were found in areas immediately downwind from agricultural/pasture land. Among three other measured air pollutants [fine particulate matter, elemental carbon (a marker of traffic in Fresno), and coarse particulate matter (PMc)], PMc was the only pollutant correlated with endotoxin. Endotoxin, however, was the most spatially variable. Conclusions Our data support the need to evaluate the spatial/temporal variability of endotoxin concentrations, rather than relying on a few measurements made at one location, in studies of exposure and and respiratory health effects, particularly in children with asthma and other chronic respiratory diseases. PMID:20494854

  10. Exposure to grain dust in Great Britain.

    PubMed

    Spankie, Sally; Cherrie, John W

    2012-01-01

    Airborne grain dust is a complex mixture of fragments of organic material from grain, plus mineral matter from soil, and possible insect, fungal, or bacterial contamination or their toxic products, such as endotoxin. In the 1990s, grain workers in Britain were frequently exposed to inhalable dust >10 mg.m(-3) (8 h), with particularly high exposures being found at terminals where grain was imported or exported and in drying operations (personal exposure typically approximately 20 mg.m(-3)). Since then, the industry has made substantial progress in improving the control of airborne dust through better-designed processes, increased automation, and an improved focus on product quality. We have used information from the published scientific literature and a small survey of industry representatives to estimate current exposure levels. These data suggest that current long-term exposure to inhalable dust for most workers is on average less than approximately 3 mg.m(-3), with perhaps 15-20% of individual personal exposures being >10 mg.m(-3). There are no published data from Britain on short-term exposure during cleaning and other tasks. We have estimated average levels for a range of tasks and judge that the highest levels, for example during some cleaning activities and certain process tasks such as loading and packing, are probably approximately10 mg.m(-3). Endotoxin levels were judged likely to be <10⁴ EU m(-3) throughout the industry provided inhalable dust levels are <10 mg.m(-3). There are no published exposure data on mycotoxin, respirable crystalline silica, and mite contamination but these are not considered to present widespread problems in the British industry. Further research should be carried out to confirm these findings.

  11. SUBCHRONIC ENDOTOXIN INHALATION CAUSES PERSISTENT AIRWAY DISEASE

    EPA Science Inventory

    ABSTRACT

    The endotoxin component of organic dusts causes acute reversible airflow obstruction and airway inflammation. To test the hypothesis that endotoxin alone causes airway remodeling, we have compared the response of two inbred mouse strains to subchronic endotoxin ...

  12. Endotoxin Studies And Biosolids Stabilization Research

    EPA Science Inventory

    This presentation has three parts; a review of bench-scale endotoxin research, a review of observations from a field scale endotoxin release study, and discussion of biosolids stabilization and characterization by PLFA/FAME microbial community analysis. Endotoxins are part of th...

  13. Elevated Airborne Exposures of Teenagers to Manganese, Chromium, and Iron from Steel Dust and New York City’s Subway System

    PubMed Central

    CHILLRUD, STEVEN N.; EPSTEIN, DAVID; ROSS, JAMES M.; SAX, SONJA N.; PEDERSON, DEE; SPENGLER, JOHN D.; KINNEY, PATRICK L.

    2011-01-01

    There is increasing interest in potential health effects of airborne exposures to hazardous air pollutants at relatively low levels. This study focuses on sources, levels, and exposure pathways of manganese, chromium, and iron among inner-city high school students in New York City (NYC) and the contribution of subways. Samples of fine particulate matter (PM2.5) were collected during winter and summer over 48 h periods in a variety of settings including inside homes, outdoors, and personal samples (i.e., sampling packs carried by subjects). PM2.5 samples were also collected in the NYC subway system. For NYC, personal samples had significantly higher concentrations of iron, manganese, and chromium than did home indoor and ambient samples. The ratios and strong correlations between pairs of elements suggested steel dust as the source of these metals for a large subset of the personal samples. Time–activity data suggested NYC subways as a likely source of these elevated personal metals. In duplicate PM2.5 samples that integrated 8 h of underground subway exposure, iron, manganese, and chromium levels (>2 orders of magnitude above ambient levels) and their ratios were consistent with the elevated personal exposures. Steel dust in the NYC subway system was the dominant source of airborne exposures to iron, manganese, and chromium for many young people enrolled in this study, with the same results expected for other NYC subway riders who do not have occupational exposures to these metals. However, there are currently no known health effects at the exposure levels observed in this study. PMID:14968857

  14. Gender Difference in Bacteria Endotoxin-Induced Inflammatory and Anorexic Responses.

    PubMed

    Kuo, Shiu-Ming

    2016-01-01

    Inflammation-related anorexic response has been observed in systemic diseases as well as in localized infection and is an important issue in patient care. We tested the hypothesis that upon the same endotoxin exposure, males have more severe inflammatory responses and thus suffer from more negative effect on appetite. Ten-week old male and female mice were compared in their plasma levels of pro-inflammatory cytokines after a body weight-based i.p. injection of bacterial endotoxin lipopolysaccharide. Male mice consistently showed significantly higher levels of IL6 and TNFα than female mice. The difference was observed starting at 3 hours after the systemic endotoxin exposure. It was independent of the level of endotoxin dosage and of the genotype of the anti-inflammatory cytokine, IL10. Interestingly, endotoxin-injected male mice also had significantly higher plasma IL10 levels compared to the female mice. Pre-puberty young mice showed no gender differences in the plasma levels of IL6, TNFα and IL10. Their cytokine levels were mostly between that of the adult males and females. Consistent with the higher inflammatory response in male mice, the endotoxin exposure also led to significantly more appetite loss in male mice at a range of doses in two strains of mice. Saline injection in the absence of endotoxin affected neither the cytokine levels nor the appetite. Although a direct mechanistic link between inflammation parameters and appetite was not addressed here, the results support that male gender could be a risk factor for higher pro-inflammatory cytokines and anorexic response after the endotoxin exposure. PMID:27631979

  15. Gender Difference in Bacteria Endotoxin-Induced Inflammatory and Anorexic Responses

    PubMed Central

    2016-01-01

    Inflammation-related anorexic response has been observed in systemic diseases as well as in localized infection and is an important issue in patient care. We tested the hypothesis that upon the same endotoxin exposure, males have more severe inflammatory responses and thus suffer from more negative effect on appetite. Ten-week old male and female mice were compared in their plasma levels of pro-inflammatory cytokines after a body weight-based i.p. injection of bacterial endotoxin lipopolysaccharide. Male mice consistently showed significantly higher levels of IL6 and TNFα than female mice. The difference was observed starting at 3 hours after the systemic endotoxin exposure. It was independent of the level of endotoxin dosage and of the genotype of the anti-inflammatory cytokine, IL10. Interestingly, endotoxin-injected male mice also had significantly higher plasma IL10 levels compared to the female mice. Pre-puberty young mice showed no gender differences in the plasma levels of IL6, TNFα and IL10. Their cytokine levels were mostly between that of the adult males and females. Consistent with the higher inflammatory response in male mice, the endotoxin exposure also led to significantly more appetite loss in male mice at a range of doses in two strains of mice. Saline injection in the absence of endotoxin affected neither the cytokine levels nor the appetite. Although a direct mechanistic link between inflammation parameters and appetite was not addressed here, the results support that male gender could be a risk factor for higher pro-inflammatory cytokines and anorexic response after the endotoxin exposure. PMID:27631979

  16. DARTAB: a program to combine airborne radionuclide environmental exposure data with dosimetric and health effects data to generate tabulations of predicted health impacts

    SciTech Connect

    Begovich, C.L.; Eckerman, K.F.; Schlatter, E.C.; Ohr, S.Y.; Chester, R.O.

    1981-08-01

    The DARTAB computer code combines radionuclide environmental exposure data with dosimetric and health effects data to generate tabulations of the predicted impact of radioactive airborne effluents. DARTAB is independent of the environmental transport code used to generate the environmental exposure data and the codes used to produce the dosimetric and health effects data. Therefore human dose and risk calculations need not be added to every environmental transport code. Options are included in DARTAB to permit the user to request tabulations by various topics (e.g., cancer site, exposure pathway, etc.) to facilitate characterization of the human health impacts of the effluents. The DARTAB code was written at ORNL for the US Environmental Protection Agency, Office of Radiation Programs.

  17. Intestinal radiation syndrome: sepsis and endotoxin

    SciTech Connect

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.

    1985-03-01

    Rats were whole-body irradiated with 8-MeV cyclotron-produced neutrons and /sup 137/Cs ..gamma.. rays to study the role of enteric bacteria and endotoxin in the intestinal radiation syndrome. Decrease in intestinal weight was used as an index of radiation-induced breakdown of the mucosa. Neutron and ..gamma..-ray doses that were sublethal for intestinal death resulted in a dose-dependent decrease in intestinal weight, reaching minimal values 2 to 3 days after exposure, followed by recovery within 5 days after irradiation. Neutron and photon doses that caused intestinal death resulted in greater mucosal breakdown with little or no evidence of mucosal recovery. The presence of fluid in the intestine and diarrhea, but not bacteremia or endotoxemia, were related to mucosal breakdown and recovery. Neither sepsis nor endotoxin could be detected in liver samples taken at autopsy from animals which died a short time earlier from intestinal injury. These results suggest that overt sepsis and endotoxemia do not play a significant role in the intestinal radiation syndrome.

  18. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT RESEARCH PLAN

    EPA Science Inventory

    The goal of the Western Airborne Contaminants Assessment Project (WACAP) is to assess the deposition of airborne contaminants in Western National Parks, providing regional and local information on exposure, accumulation, impacts, and probable sources. This project is being desig...

  19. Estimating individual-level exposure to airborne polycyclic aromatic hydrocarbons throughout the gestational period based on personal, indoor, and outdoor monitoring

    SciTech Connect

    Choi, H.; Perera, F.; Pac, A.; Wang, L.; Flak, E.; Mroz, E.; Jacek, R.; Chai-Onn, T.; Jedrychowski, W.; Masters, E.; Camann, D.; Spengler, J.

    2008-11-15

    Current understanding on health effects of long-term polycyclic aromatic hydrocarbon (PAH) exposure is limited by lack of data on time-varying nature of the pollutants at an individual level. In a cohort of pregnant women in Krakow, Poland, we examined the contribution of temporal, spatial, and behavioral factors to prenatal exposure to airborne PAHs within each trimester and developed a predictive model of PAH exposure over the entire gestational period. The observed personal, indoor, and outdoor B(a)P levels we observed in Krakow far exceed the recommended Swedish guideline value for B(a)P of 0.1 ng/m{sup 3}. Based on simultaneously monitored levels, the outdoor PAH level alone accounts for 93% of total variability in personal exposure during the heating season. Living near the Krakow bus depot, a crossroad, and the city, center and time spent outdoors or commuting were not associated with higher personal exposure. During the nonheating season only, a 1-hr increase in environmental tobacco smoke (ETS) exposure was associated with a 10-16% increase in personal exposure to the nine measured PAHs. A 1{degree}C decrease in ambient temperature was associated with a 3-5% increase in exposure to benz(a)anthracene, benzo(k)fluoranthene, and dibenz(a,h)anthracene, after accounting for the outdoor concentration. A random effects model demonstrated that mean personal exposure at a given gestational period depends on the season, residence location, and ETS. Considering that most women reported spending < 3 hr/day outdoors, most women in the study were exposed to outdoor-originating PAHs within the indoor setting. Cross-sectional, longitudinal monitoring supplemented with questionnaire data allowed development of a gestation-length model of individual-level exposure with high precision and validity.

  20. Assessment of workers' exposure to bioaerosols in a French cheese factory.

    PubMed

    Simon, Xavier; Duquenne, Philippe

    2014-07-01

    Hundreds of different cheeses are produced in France, where 23.9kg of cheese were consumed per inhabitant in 2009, when it was ranked the second cheese-consuming nation. To meet this considerable demand, a large number of cheese factories exist where many workers, especially cheese washers, may be exposed to fungal bioaerosols that can lead to adverse toxinic and allergic effects. Airborne bacteria, fragments, or microbial by-products (endotoxins) are also found and contribute to total worker exposure. However, there is almost no published data concerning worker exposure or characteristics of bioaerosols emitted during these activities. Here, we measured the parameters (concentrations, species present, and size distribution) of the culturable fungal bioaerosol emitted in a French natural-rind cheese-maturing cellar. Concentrations of airborne bacteria and endotoxins were also measured. The main tasks were investigated using stationary or personal sampling over three consecutive days. Depending on the work area, high concentrations of culturable mesophilic microorganisms were measured (using closed-face cassettes): from 10(4) to 2×10(8) CFU m(-3) for fungi and from 10(3) to 10(6) CFU m(-3) for bacteria. These concentrations are 10- to 100000-fold higher than those measured at two reference points (indoor and outdoor) that are assumed not to be contaminated by the plant's activities. Endotoxin concentrations were between 10 and 300 EU m(-3) in the plant. Exposure was further assessed by identifying the predominant culturable fungi (allergenic Mucor fuscus and Penicillium sp.) and by measuring particle size distributions (cascade impactor). Airborne fungal entities (spores, mycelium strands and fragments, agglomerates, etc.) were found with aerodynamic diameters from 3 to over 20 µm. A metrological approach was used to fully characterize the culturable fungal aerosols generated during cheese maturing in this plant. The results show that workers are exposed to

  1. Assessment of workers' exposure to bioaerosols in a French cheese factory.

    PubMed

    Simon, Xavier; Duquenne, Philippe

    2014-07-01

    Hundreds of different cheeses are produced in France, where 23.9kg of cheese were consumed per inhabitant in 2009, when it was ranked the second cheese-consuming nation. To meet this considerable demand, a large number of cheese factories exist where many workers, especially cheese washers, may be exposed to fungal bioaerosols that can lead to adverse toxinic and allergic effects. Airborne bacteria, fragments, or microbial by-products (endotoxins) are also found and contribute to total worker exposure. However, there is almost no published data concerning worker exposure or characteristics of bioaerosols emitted during these activities. Here, we measured the parameters (concentrations, species present, and size distribution) of the culturable fungal bioaerosol emitted in a French natural-rind cheese-maturing cellar. Concentrations of airborne bacteria and endotoxins were also measured. The main tasks were investigated using stationary or personal sampling over three consecutive days. Depending on the work area, high concentrations of culturable mesophilic microorganisms were measured (using closed-face cassettes): from 10(4) to 2×10(8) CFU m(-3) for fungi and from 10(3) to 10(6) CFU m(-3) for bacteria. These concentrations are 10- to 100000-fold higher than those measured at two reference points (indoor and outdoor) that are assumed not to be contaminated by the plant's activities. Endotoxin concentrations were between 10 and 300 EU m(-3) in the plant. Exposure was further assessed by identifying the predominant culturable fungi (allergenic Mucor fuscus and Penicillium sp.) and by measuring particle size distributions (cascade impactor). Airborne fungal entities (spores, mycelium strands and fragments, agglomerates, etc.) were found with aerodynamic diameters from 3 to over 20 µm. A metrological approach was used to fully characterize the culturable fungal aerosols generated during cheese maturing in this plant. The results show that workers are exposed to

  2. Novel endotoxin assay by laser light-scattering particle-counting method.

    PubMed

    Mitsumoto, Kotaro; Yabusaki, Katsumi; Kobayashi, Koji; Shirasawa, Yoshiaki; Obata, Toru

    2009-01-01

    Exposure of Limulus amoebocyte lysate to endotoxin under stirring produced light-reflective particles that appeared to be coagulin polymers. A laser light-scattering particle counter, the PA-200, detected these particles sensitively. The PA-200 detected endotoxin at a concentration as low as 0.00015 EU/ml in 71 min, whereas the minimum endotoxin concentration measured by a turbidimeter, ET-2000, was 0.0005 EU/ml in 138 min. Moreover, PA-200 was much less affected by the presence of colored substances and refractive materials than was ET-2000. We propose that the high sensitivity, speed, and high interference tolerance of the laser light-scattering particle-counting method make it more useful than the widely used turbidimetric method for quantitative endotoxin assay.

  3. Meteo-climatic conditions influence the contribution of endotoxins to PM10 in an urban polluted environment.

    PubMed

    Traversi, D; Alessandria, L; Schilirò, T; Chiadò Piat, S; Gilli, G

    2010-02-01

    A decrease in inhalable particulate matter (PM10) pollution is a top priority in urban areas of northern Italy. The sources of PM10 are both anthropogenic and natural. The former have been broadly investigated while the latter are less well known. Endotoxins are natural compounds of PM10 and are potentially toxic. Endotoxins are part of the outer membrane of Gram-negative bacteria. Their health effects are linked to environmental exposure. The effects mainly consist of respiratory symptoms, including pulmonary function decline. The occurrence of endotoxins has been proven in several occupational environments where organic materials supply an optimal substrate for bacteria growth. Knowledge about the presence of these contaminants in the environment is limited. The aim of this work is to evaluate the endotoxin levels of PM10 in the urban air of Turin, and to investigate the influence of seasonal and meteo-climatic factors. The sampling was conducted from January to December 2007. Endotoxin determination was performed by an LAL assay after extraction optimization. The PM10 levels ranged from 11.90 to 104.74 microg/m(3) (48.28 +/- 23.09) while the endotoxin levels ranged between 0.09 and 0.94 EU/m(3) (0.42 +/- 0.23). The seasonal trends of PM10 and endotoxin are inversely proportional. There is a statistically significant correlation between endotoxin and temperature (r = 0.532 p < 0.01), as well as between endotoxin and relative humidity (r = -0.457 p < 0.01). However, temperature has a predominant role. We observed that urban endotoxin concentrations are narrow in range and that the contribution of endotoxins to the total PM10 is only two millionths.

  4. Lack of spatial variation of endotoxin in ambient particulate matter across a German metropolitan area

    NASA Astrophysics Data System (ADS)

    Morgenstern, Verena; Carty, Cara L.; Gehring, Ulrike; Cyrys, Josef; Bischof, Wolfgang; Heinrich, Joachim

    In this study, we describe the spatial variation of endotoxin across an urban setting using Geographic Information Systems (GIS) methods. We also identify potential sources of endotoxin that account for between-site variability and compare endotoxin levels in particulate matter with a 50% aerodynamic cut-off diameter of 2.5 μm (PM 2.5) and of 10 μm (PM 10). In 1999-2000, we collected PM 2.5 and PM 10 in Munich urban air and measured soluble endotoxin concentrations in both particle fractions. Using Teflon filters and Harvard impactors, PM 2.5 was collected at 40 outdoor monitoring sites across Munich and PM 10 at a subset of these sites ( n=12). Approximately four samples were collected at each site for a total of 158 PM 2.5 samples and 48 PM 10 samples. We visited and characterized the surrounding 100 m of each site for potential endotoxin sources. The geometric mean endotoxin concentration for all sites was 1.46 EU mg -1 PM 2.5 (95% confidence intervals (CI): 1.21-1.77) and at the subset of the sites was 1.30 EU mg -1 PM 2.5 (95% CI: 1.01-1.67 EU mg -1 PM 2.5). Endotoxin levels in PM 10 were higher, 3.91 EU mg -1 PM 10 (95% CI: 3.03-5.03 EU mg -1 PM 10), than in PM 2.5 and were moderately correlated, r=0.51. All endotoxin concentrations measured in this study were <5.5 EU m -3 and thus lower than the accepted thresholds for acute adverse health effects for occupational exposures. Sites with more potential sources ( n⩾3) had slightly higher mean endotoxin levels (MR: 1.30 for EU mg -1 PM 2.5 and 1.13 for EU m -3 PM 2.5) than sites with no identified sources. Based on the ranges of endotoxin levels at the different sites, we found very little spatial variation in ambient endotoxin concentrations across the metropolitan area of Munich using inverse distance weighting method (IDW) methods ( R2=0.013 for EU mg -1 PM 2.5 and R2=0.020 for EU m -3 PM 2.5). Potential sources of endotoxin surrounding the sites only partly explained the variation seen.

  5. Human exposure to airborne aldehydes in Chinese medicine clinics during moxibustion therapy and its impact on risks to health.

    PubMed

    Hsu, Yi-Chyun; Chao, How-Ran; Shih, Shun-I

    2015-01-01

    Many air toxicants, and especially aldehydes, are generated by moxibustion, which means burning Artemisia argyi. Our goal was to investigate indoor-air aldehyde emissions in Chinese medicine clinics (CMCs) during moxibustion to further evaluate the potential health risks, including cancer risk and non-cancer risk, to the medical staff and adult patients. First, the indoor-air-quality in 60 public sites, including 15 CMCs, was investigated. Four CMCs with frequent use of moxibustion were selected from the 15 CMCs to gather the indoor airborne aldehydes in the waiting and therapy rooms. The mean values of formaldehyde and acetaldehyde in the CMCs' indoor air were 654 and 4230 μg m(-3), respectively, in the therapy rooms, and 155 and 850 μg m(-3), respectively, in the waiting rooms. The average lifetime cancer risks (Rs) and non-cancer risks (hazard quotients: HQs) of airborne formaldehyde and acetaldehyde among the CMC medical staff exceeded the acceptable criteria (R < 1.00 × 10(-3) and HQ < 1.00) for occupational workers. The patients' Rs and HQs were also slightly higher than the critical values (R = 1.00 × 10(-6) and HQ = 1.00). Our results indicate that airborne aldehydes pose a significant threat to the health of medical staff, and slightly affected the patients' health, during moxibustion in the CMCs.

  6. Recent advances in biosensor based endotoxin detection.

    PubMed

    Das, A P; Kumar, P S; Swain, S

    2014-01-15

    Endotoxins also referred to as pyrogens are chemically lipopolysaccharides habitually found in food, environment and clinical products of bacterial origin and are unavoidable ubiquitous microbiological contaminants. Pernicious issues of its contamination result in high mortality and severe morbidities. Standard traditional techniques are slow and cumbersome, highlighting the pressing need for evoking agile endotoxin detection system. The early and prompt detection of endotoxin assumes prime importance in health care, pharmacological and biomedical sectors. The unparalleled recognition abilities of LAL biosensors perched with remarkable sensitivity, high stability and reproducibility have bestowed it with persistent reliability and their possible fabrication for commercial applicability. This review paper entails an overview of various trends in current techniques available and other possible alternatives in biosensor based endotoxin detection together with its classification, epidemiological aspects, thrust areas demanding endotoxin control, commercially available detection sensors and a revolutionary unprecedented approach narrating the influence of omics for endotoxin detection. PMID:23934306

  7. Recent advances in biosensor based endotoxin detection.

    PubMed

    Das, A P; Kumar, P S; Swain, S

    2014-01-15

    Endotoxins also referred to as pyrogens are chemically lipopolysaccharides habitually found in food, environment and clinical products of bacterial origin and are unavoidable ubiquitous microbiological contaminants. Pernicious issues of its contamination result in high mortality and severe morbidities. Standard traditional techniques are slow and cumbersome, highlighting the pressing need for evoking agile endotoxin detection system. The early and prompt detection of endotoxin assumes prime importance in health care, pharmacological and biomedical sectors. The unparalleled recognition abilities of LAL biosensors perched with remarkable sensitivity, high stability and reproducibility have bestowed it with persistent reliability and their possible fabrication for commercial applicability. This review paper entails an overview of various trends in current techniques available and other possible alternatives in biosensor based endotoxin detection together with its classification, epidemiological aspects, thrust areas demanding endotoxin control, commercially available detection sensors and a revolutionary unprecedented approach narrating the influence of omics for endotoxin detection.

  8. Occupational exposure to polycyclic aromatic hydrocarbons in airborne particulate matter: validation and application of a gas chromatography-mass spectrometry analytical method.

    PubMed

    Fioretti, Marzia; Catrambone, Tamara; Gordiani, Andrea; Cabella, Renato

    2010-12-01

    This study concerns the validation of an analytical method for the measurement of occupational exposure to trace levels of polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter (APM). Personal exposure to selected PAHs of five workers occupationally exposed to urban pollution in Rome, Italy, was evaluated. The samples were collected over 10 days evenly distributed during winter and summer of 2008. Polycyclic aromatic hydrocarbons were collected by a sampling pump and trapped in polytetrafluoroethylene filters; ultrasonic extraction was applied to extract PAH species from the matrix with toluene, and the concentrated extract was quantitatively analyzed by GC/MS. The analytical method was optimized and validated using a standard reference material of urban dust (SRM 1649a). Detection limits ranged from 0.8 ng per sample for indeno [1,2,3-cd] pyrene to 20.4 ng for sample for anthracene. Experimental results of the 50 personal samples collected showed that phenanthrene was the predominant polycyclic aromatic hydrocarbon [95% CI (32.42-41.13 ng m(-3))]; the highest benzo[a]pyrene concentration was 2.58 ng m(-3), approximately 2-fold higher than European annual target values (1 ng m(-3)). Seasonal variations of personal exposure to selected PAHs suggested higher emissions and reduced atmospheric reactivity of PAH compounds in winter. The analytical method was a suitable procedure for the determination of 13 of the 16 priority PAHs in APM personal samples and can be considered a useful tool to evaluate occupational exposure to low PAH levels.

  9. Human endotoxin tolerance is associated with enrichment of the CD14+ CD16+ monocyte subset.

    PubMed

    Domínguez-Nieto, Aimée; Zentella, Alejandro; Moreno, José; Ventura, José L; Pedraza, Sigifredo; Velázquez, Juan R

    2015-01-01

    Prior exposure to lipopolysaccharides (LPS) induces a state of cell resistance to subsequent LPS restimulation, known as endotoxin tolerance, mainly by repressing the expression of pro-inflammatory cytokines. We established an endotoxin tolerance model in human monocytes Endotoxin-tolerant cells showed a decrease in IκBα degradation and diminished expression of Tumor necrosis factor (TNF) (both messenger RNA [mRNA] and protein content). The myeloid differentiation factor 88 (MyD88)/MyD88 splice variant (MyD88s) ratio, an indirect way to test the Toll-like receptor 4 (TLR4) MyD88-dependent signaling cascade, did not change in endotoxin-tolerant cells when compared to LPS-stimulated or -unstimulated ones. Remarkably, cell population analysis indicated a significant increase of the CD14+ CD16+ subset only under the endotoxin-tolerant condition. Furthermore, endotoxin-tolerant cells produced higher amounts of C-X-C motif chemokine 10 (CXCL10), a typical MyD88-independent cytokine.

  10. Human endotoxin tolerance is associated with enrichment of the CD14+ CD16+ monocyte subset.

    PubMed

    Domínguez-Nieto, Aimée; Zentella, Alejandro; Moreno, José; Ventura, José L; Pedraza, Sigifredo; Velázquez, Juan R

    2015-01-01

    Prior exposure to lipopolysaccharides (LPS) induces a state of cell resistance to subsequent LPS restimulation, known as endotoxin tolerance, mainly by repressing the expression of pro-inflammatory cytokines. We established an endotoxin tolerance model in human monocytes Endotoxin-tolerant cells showed a decrease in IκBα degradation and diminished expression of Tumor necrosis factor (TNF) (both messenger RNA [mRNA] and protein content). The myeloid differentiation factor 88 (MyD88)/MyD88 splice variant (MyD88s) ratio, an indirect way to test the Toll-like receptor 4 (TLR4) MyD88-dependent signaling cascade, did not change in endotoxin-tolerant cells when compared to LPS-stimulated or -unstimulated ones. Remarkably, cell population analysis indicated a significant increase of the CD14+ CD16+ subset only under the endotoxin-tolerant condition. Furthermore, endotoxin-tolerant cells produced higher amounts of C-X-C motif chemokine 10 (CXCL10), a typical MyD88-independent cytokine. PMID:25172544

  11. Characteristics of airborne bacteria in Mumbai urban environment.

    PubMed

    Gangamma, S

    2014-08-01

    Components of biological origin constitute small but a significant proportion of the ambient airborne particulate matter (PM). However, their diversity and role in proinflammatory responses of PM are not well understood. The present study characterizes airborne bacterial species diversity in Mumbai City and elucidates the role of bacterial endotoxin in PM induced proinflammatory response in ex vivo. Airborne bacteria and endotoxin samples were collected during April-May 2010 in Mumbai using six stage microbial impactor and biosampler. The culturable bacterial species concentration was measured and factors influencing the composition were identified by principal component analysis (PCA). The biosampler samples were used to stimulate immune cells in whole blood assay. A total of 28 species belonging to 17 genera were identified. Gram positive and spore forming groups of bacteria dominated the airborne culturable bacterial concentration. The study indicated the dominance of spore forming and human or animal flora derived pathogenic/opportunistic bacteria in the ambient air environment. Pathogenic and opportunistic species of bacteria were also present in the samples. TNF-α induction by PM was reduced (35%) by polymyxin B pretreatment and this result was corroborated with the results of blocking endotoxin receptor cluster differentiation (CD14). The study highlights the importance of airborne biological particles and suggests need of further studies on biological characterization of ambient PM.

  12. Bioaerosol exposure assessment in the workplace: the past, present and recent advances.

    PubMed

    Eduard, Wijnand; Heederik, Dick; Duchaine, Caroline; Green, Brett James

    2012-02-01

    Louis Pasteur described the first measurements of airborne microorganisms in 1861. A century later, the inhalation of spores from thermophilic microorganisms was shown to induce attacks of farmers' lung in patients with this disease, while endotoxins originating from Gram-negative bacteria were identified as causal agents for byssinosis in cotton workers. Further epidemiological and toxicological studies have demonstrated inflammatory, respiratory, and pathogenic effects following exposure to bioaerosols. Exposure assessment is often confounded by the diversity of bioaerosol agents in the environment. Microorganisms represent a highly diverse group that may vary in toxicity. Fungi and bacteria are mainly quantified as broad groups using a variety of viable and nonviable assessment methods. Endotoxins and β(1 → 3)-glucans are mainly measured by their activity in the Limulus amebocyte lysate assay, enzymes by immuno-chemical methods and mycotoxins by liquid chromatography-mass spectrometry. Few health-based occupational exposure limits (OELs) are available for risk assessment. For endotoxins, a health-based OEL of 90 endotoxin units m(-3) has been proposed in the Netherlands. A criteria document for fungal spores recently proposed a lowest observed effect level of 100,000 spores m(-3) for non-pathogenic and non-mycotoxin producing species based on inflammatory respiratory effects. Recent developments in bioaerosol assessment were presented at the Organic Dust Tromsø Symposium including molecular biological methods for infectious agents and organisms that are difficult to cultivate; studies of submicronic and hyphal fragments from fungi; the effect of biodiversity of microorganisms in asthma studies; and new/improved measurement methods for fungal antigens, enzymes and allergens. Although exposure assessment of bioaerosol agents is complex and limited by the availability of methods and criteria, the field is rapidly evolving.

  13. Bioaerosol exposure assessment in the workplace: the past, present and recent advances.

    PubMed

    Eduard, Wijnand; Heederik, Dick; Duchaine, Caroline; Green, Brett James

    2012-02-01

    Louis Pasteur described the first measurements of airborne microorganisms in 1861. A century later, the inhalation of spores from thermophilic microorganisms was shown to induce attacks of farmers' lung in patients with this disease, while endotoxins originating from Gram-negative bacteria were identified as causal agents for byssinosis in cotton workers. Further epidemiological and toxicological studies have demonstrated inflammatory, respiratory, and pathogenic effects following exposure to bioaerosols. Exposure assessment is often confounded by the diversity of bioaerosol agents in the environment. Microorganisms represent a highly diverse group that may vary in toxicity. Fungi and bacteria are mainly quantified as broad groups using a variety of viable and nonviable assessment methods. Endotoxins and β(1 → 3)-glucans are mainly measured by their activity in the Limulus amebocyte lysate assay, enzymes by immuno-chemical methods and mycotoxins by liquid chromatography-mass spectrometry. Few health-based occupational exposure limits (OELs) are available for risk assessment. For endotoxins, a health-based OEL of 90 endotoxin units m(-3) has been proposed in the Netherlands. A criteria document for fungal spores recently proposed a lowest observed effect level of 100,000 spores m(-3) for non-pathogenic and non-mycotoxin producing species based on inflammatory respiratory effects. Recent developments in bioaerosol assessment were presented at the Organic Dust Tromsø Symposium including molecular biological methods for infectious agents and organisms that are difficult to cultivate; studies of submicronic and hyphal fragments from fungi; the effect of biodiversity of microorganisms in asthma studies; and new/improved measurement methods for fungal antigens, enzymes and allergens. Although exposure assessment of bioaerosol agents is complex and limited by the availability of methods and criteria, the field is rapidly evolving. PMID:22267210

  14. Endotoxin removal by radio frequency gas plasma (glow discharge)

    NASA Astrophysics Data System (ADS)

    Poon, Angela

    2011-12-01

    Contaminants remaining on implantable medical devices, even following sterilization, include dangerous fever-causing residues of the outer lipopolysaccharide-rich membranes of Gram-negative bacteria such as the common gut microorganism E. coli. The conventional method for endotoxin removal is by Food & Drug Administration (FDA)-recommended dry-heat depyrogenation at 250°C for at least 45 minutes, an excessively time-consuming high-temperature technique not suitable for low-melting or heat-distortable biomaterials. This investigation evaluated the mechanism by which E. coli endotoxin contamination can be eliminated from surfaces during ambient temperature single 3-minute to cumulative 15-minute exposures to radio-frequency glow discharge (RFGD)-generated residual room air plasmas activated at 0.1-0.2 torr in a 35MHz electrodeless chamber. The main analytical technique for retained pyrogenic bio-activity was the Kinetic Chromogenic Limulus Amebocyte Lysate (LAL) Assay, sufficiently sensitive to document compliance with FDA-required Endotoxin Unit (EU) titers less than 20 EU per medical device by optical detection of enzymatic color development corresponding to < 0.5 EU/ml in sterile water extracts of each device. The main analytical technique for identification of chemical compositions, amounts, and changes during sequential reference Endotoxin additions and subsequent RFGD-treatment removals from infrared (IR)-transparent germanium (Ge) prisms was Multiple Attenuated Internal Reflection (MAIR) infrared spectroscopy sensitive to even monolayer amounts of retained bio-contaminant. KimaxRTM 60 mm x 15 mm and 50mm x 15mm laboratory glass dishes and germanium internal reflection prisms were inoculated with E. coli bacterial endotoxin water suspensions at increments of 0.005, 0.05, 0.5, and 5 EU, and characterized by MAIR-IR spectroscopy of the dried residues on the Ge prisms and LAL Assay of sterile water extracts from both glass and Ge specimens. The Ge prism MAIR

  15. Minimizing the exposure of airborne pathogens by upper-room ultraviolet germicidal irradiation: an experimental and numerical study.

    PubMed

    Yang, Y; Chan, W Y; Wu, C L; Kong, R Y C; Lai, A C K

    2012-12-01

    There has been increasing interest in the use of upper-room ultraviolet germicidal irradiation (UVGI) because of its proven effectiveness in disinfecting airborne pathogens. An improved drift flux mathematical model is developed for optimizing the design of indoor upper-room UVGI systems by predicting the distribution and inactivation of bioaerosols in a ventilation room equipped with a UVGI system. The model takes into account several bacteria removal mechanisms such as convection, turbulent diffusion, deposition and UV inactivation. Before applying the model, the natural die-off rate and susceptibility constants of bioaerosols were measured experimentally. Two bacteria aerosols, Escherichia coli and Serratia marcescens, were tested for this purpose. It was found out that the general decay trend of the bioaerosol concentration predicted by the numerical model agrees well with the experimental measurements. The modelling results agree better with experimental observations for the case when the UVGI inactivation mechanism dominates at the upper-room region than for the case without UVGI. The numerical results also illustrate that the spatial distribution of airborne bacteria was influenced by both air-flow pattern and irradiance distribution. In addition to predicting the local variation of concentration, the model assesses the overall performance of an upper-room UVGI system. This model has great potential for optimizing the design of indoor an upper-room UVGI systems.

  16. Airborne Fiber Size Characterization in Exposure Estimation: Evaluation of a Modified Transmission Electron Microcopy Protocol for Asbestos and Potential Use for Carbon Nanotubes and Nanofibers

    PubMed Central

    Dement, John M.; Kuempel, Eileen D.; Zumwalde, Ralph D.; Ristich, Anna M.; Fernback, Joseph E.; Smith, Randall J.

    2015-01-01

    Background Airborne fiber size has been shown to be an important factor relative to adverse lung effects of asbestos and suggested in animal studies of carbon nanotubes and nanofibers (CNT/CNF). Materials and Methods The International Standards Organization (ISO) transmission electron microscopy (TEM) method for asbestos was modified to increase the statistical precision of fiber size determinations, improve efficiency, and reduce analysis costs. Comparisons of the fiber size distributions and exposure indices by laboratory and counting method were performed. Results No significant differences in size distributions by the ISO and modified ISO methods were observed. Small but statistically-significant inter-lab differences in the proportion of fibers in some size bins were found, but these differences had little impact on the summary exposure indices. The modified ISO method produced slightly more precise estimates of the long fiber fraction (>15 μm). Conclusions The modified ISO method may be useful for estimating size-specific structure exposures, including CNT/CNF, for risk assessment research. PMID:25675894

  17. 21 CFR 866.3210 - Endotoxin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay....

  18. 21 CFR 866.3210 - Endotoxin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay....

  19. 21 CFR 866.3210 - Endotoxin assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay....

  20. 21 CFR 866.3210 - Endotoxin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay....

  1. 21 CFR 866.3210 - Endotoxin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay....

  2. Protection of the vehicle cab environment against bacteria, fungi and endotoxins in composting facilities.

    PubMed

    Schlosser, O; Huyard, A; Rybacki, D; Do Quang, Z

    2012-06-01

    exceeded the benchmark value for short-term respiratory effects suggests that front-end loaders and mobile mixers in composting facilities should be fitted with a pressurisation and HEPA filtration system, regardless of whether or not the facility is indoors or outdoors. Regarding the tractors, exposure inside the cabs was not significantly reduced. However, in this study, there was a less than 0.01% risk of exceeding the bench mark value associated with fungi related short-term respiratory effects during an 1-h per day windrow turning operation. Pressurisation and a HEPA filtration system can provide safe working conditions inside loaders and mobile mixer with regard to airborne bacteria, fungi and endotoxins in composting facilities. However, regular thorough cleaning of the vehicle cab, as well as overalls and shoes cleaning, and mitigation of leakage in the filter-sealing system are necessary to achieve high levels of protection efficiency. PMID:22330264

  3. Toxicologic interactions between ozone and bacterial endotoxin

    SciTech Connect

    Peavy, D.L.; Fairchild, E.J. II

    1987-02-01

    The effects of acute exposure of mice to bacterial lipopolysaccharide (LPS), the endotoxin of gram negative microorganisms, and ozone (O3) have been investigated. Intraperitoneal (ip) administration of 5 mg/kg LPS to CD-1 mice followed by exposure to 15 ppm O3 for 1.5 hr produced synergistic effects as measured by pulmonary edemagenesis and lethality assays. In contrast, ip administration of 0.1-1.6 mg/kg LPS to CD-1 mice over 5 consecutive days, a dose regimen resulting in LPS tolerance, protected against a lethal challenge of 20 ppm O3 for 3 hr. A statistically significant increase in catalase and glutathione peroxidase activity was measured in homogenates of lungs obtained from CD-1 mice receiving a tolerance-inducing regimen of LPS. These results demonstrate that two, distinct toxicologic interactions can occur between O3 and bacterial LPS. Synergism between these agents could explain, in part, the increased susceptibility of O3-exposed animals to respiratory infection with gram negative microorganisms. Protection resulting from LPS-induced increases in pulmonary antioxidant activity provides additional evidence that O3 and, possibly, LPS mediate their toxicity through oxidative mechanisms.

  4. Lipid biomarker analysis for the quantitative analysis of airborne microorganisms

    SciTech Connect

    Macnaughton, S.J.; Jenkins, T.L.; Cormier, M.R.

    1997-08-01

    There is an ever increasing concern regarding the presence of airborne microbial contaminants within indoor air environments. Exposure to such biocontaminants can give rise to large numbers of different health effects including infectious diseases, allergenic responses and respiratory problems, Biocontaminants typically round in indoor air environments include bacteria, fungi, algae, protozoa and dust mites. Mycotoxins, endotoxins, pollens and residues of organisms are also known to cause adverse health effects. A quantitative detection/identification technique independent of culturability that assays both culturable and non culturable biomass including endotoxin is critical in defining risks from indoor air biocontamination. Traditionally, methods employed for the monitoring of microorganism numbers in indoor air environments involve classical culture based techniques and/or direct microscopic counting. It has been repeatedly documented that viable microorganism counts only account for between 0.1-10% of the total community detectable by direct counting. The classic viable microbiologic approach doe`s not provide accurate estimates of microbial fragments or other indoor air components that can act as antigens and induce or potentiate allergic responses. Although bioaerosol samplers are designed to damage the microbes as little as possible, microbial stress has been shown to result from air sampling, aerosolization and microbial collection. Higher collection efficiency results in greater cell damage while less cell damage often results in lower collection efficiency. Filtration can collect particulates at almost 100% efficiency, but captured microorganisms may become dehydrated and damaged resulting in non-culturability, however, the lipid biomarker assays described herein do not rely on cell culture. Lipids are components that are universally distributed throughout cells providing a means to assess independent of culturability.

  5. Obesity Increases Sensitivity to Endotoxin Liver Injury: Implications for the Pathogenesis of Steatohepatitis

    NASA Astrophysics Data System (ADS)

    Yang, Shi Qi; Zhi Lin, Hui; Lane, M. Daniel; Clemens, Mark; Diehl, Anna Mae

    1997-03-01

    Genetically obese fatty/fatty rats and obese/obese mice exhibit increased sensitivity to endotoxin hepatotoxicity, quickly developing steatohepatitis after exposure to low doses of lipopolysaccharide (LPS). Among obese animals, females are more sensitive to endotoxin liver injury than males. LPS induction of tumor necrosis factor α (TNFα ), the proven affecter of endotoxin liver injury, is no greater in the livers, white adipose tissues, or sera of obese animals than in those of lean controls. Indeed, the lowest serum concentrations of TNF occur in female obese rodents, which exhibit the most endotoxin-induced liver injury. Several cytokines that modulate the biological activity of TNF are regulated abnormally in the livers of obese animals. After exposure to LPS, mRNA of interferon γ , which sensitizes hepatocytes to TNF toxicity, is overexpressed, and mRNA levels of interleukin 10, a TNF inhibitor, are decreased. The phagocytic activity of liver macrophages and the hepatic expression of a gene encoding a macrophage-specific receptor are also decreased in obesity. This new animal model of obesity-associated liver disease demonstrates that hepatic macrophage dysfunction occurs in obesity and suggests that this might promote steatohepatitis by sensitizing hepatocytes to endotoxin.

  6. Endotoxins and other sepsis triggers.

    PubMed

    Opal, Steven M

    2010-01-01

    Endotoxin, or more accurately termed bacterial lipopolysaccharide (LPS), is recognized as the most potent microbial mediator implicated in the pathogenesis of sepsis and septic shock. Yet despite its discovery well over a century ago, the fundamental role of circulating endotoxin in the blood of most patients with septic shock remains enigmatic and a subject of considerable controversy. LPS is the most prominent 'alarm molecule' sensed by the host's early warning system of innate immunity presaging the threat of invasion of the internal milieu by Gram-negative bacterial pathogens. In small doses within a localized tissue space, LPS signaling is advantageous to the host in orchestrating an appropriate antimicrobial defense and bacterial clearance mechanisms. Conversely, the sudden release of large quantities of LPS into the bloodstream is clearly deleterious to the host, initiating the release of a dysregulated and potentially lethal array of inflammatory mediators and procoagulant factors in the systemic circulation. The massive host response to this single bacterial pattern recognition molecule is sufficient to generate diffuse endothelial injury, tissue hypoperfusion, disseminated intravascular coagulation and refractory shock. Numerous attempts to block endotoxin activity in clinical trials with septic patients have met with inconsistent and largely negative results. Yet the groundbreaking discoveries within the past decade into the precise molecular basis for LPS-mediated cellular activation and tissue injury has rekindled optimism that a new generation of therapies that specifically disrupt LPS signaling might succeed. Other microbial mediators found in Gram-positive bacterial and viral and fungal pathogens are now appreciated to activate many of the same host defense networks induced by LPS. This information is providing novel interventions in the continuing effots to improve the care of septic patients.

  7. Combined Insulin Deficiency and Endotoxin Exposure Stimulate Lipid Mobilization and Alter Adipose Tissue Signaling in an Experimental Model of Ketoacidosis in Subjects With Type 1 Diabetes: A Randomized Controlled Crossover Trial.

    PubMed

    Svart, Mads; Kampmann, Ulla; Voss, Thomas; Pedersen, Steen B; Johannsen, Mogens; Rittig, Nikolaj; Poulsen, Per L; Nielsen, Thomas S; Jessen, Niels; Møller, Niels

    2016-05-01

    Most often, diabetic ketoacidosis (DKA) in adults results from insufficient insulin administration and acute infection. DKA is assumed to release proinflammatory cytokines and stress hormones that stimulate lipolysis and ketogenesis. We tested whether this perception of DKA can be reproduced in an experimental human model by using combined insulin deficiency and acute inflammation and tested which intracellular mediators of lipolysis are affected in adipose tissue. Nine subjects with type 1 diabetes were studied twice: 1) insulin-controlled euglycemia and 2) insulin deprivation and endotoxin administration (KET). During KET, serum tumor necrosis factor-α, cortisol, glucagon, and growth hormone levels increased, and free fatty acids and 3-hydroxybutyrate concentrations and the rate of lipolysis rose markedly. Serum bicarbonate and pH decreased. Adipose tissue mRNA contents of comparative gene identification-58 (CGI-58) increased and G0/G1 switch 2 gene (G0S2) mRNA decreased robustly. Neither protein levels of adipose triglyceride lipase (ATGL) nor phosphorylations of hormone-sensitive lipase were altered. The clinical picture of incipient DKA in adults can be reproduced by combined insulin deficiency and endotoxin-induced acute inflammation. The precipitating steps involve the release of proinflammatory cytokines and stress hormones, increased lipolysis, and decreased G0S2 and increased CGI-58 mRNA contents in adipose tissue, compatible with latent ATGL stimulation. PMID:26884439

  8. AIRBORNE PARTICULATE MATTER: PHYSICO-CHEMICAL CHARACTERISTICS AND HUMAN EXPOSURE ISSUES RELATED TO HEALTH EFFECTS RESEARCH AND ASSESSMENT

    EPA Science Inventory

    Exposure to particulate matter (PM) is associated with excess mortality and morbidity, especially in individuals with cardiopulmonary disease. These epidemiologic findings are the cornerstone of EPA's revision of the PM National Ambient Quality Standards to include PM less tha...

  9. Impact of portable air filtration units on exposure of haematology-oncology patients to airborne Aspergillus fumigatus spores under field conditions.

    PubMed

    Engelhart, S; Hanfland, J; Glasmacher, A; Krizek, L; Schmidt-Wolf, I G H; Exner, M

    2003-08-01

    We undertook a one-year study to investigate the impact of the NSA model 7100A/B portable air filtration unit on exposure of haematology-oncology patients to airborne Aspergillus fumigatus spores under field conditions. Weekly measurements for airborne A. fumigatus were conducted in indoor and outdoor air, and surveillance for invasive aspergillosis was based on a combination of ward liaison, targeted chart review and consultation with the medical staff. The mean indoor A. fumigatus counts (8.1 cfu/m3; range, <0.8 to 42 cfu/m3) reflected the fungal load of outdoor air (9.4 cfu/m3; range, <0.8 to 50 cfu/m3), and were reduced by only about one third in rooms with portable air filtration units (5.3 cfu/m3; range, <0.8 to 41 cfu/m3). During the study period, a total of five cases (incidence density, 0.8 per 1000 patient-days) of invasive aspergillosis (one proven case, four suspected cases; case fatality rate 40%) were recorded. None of these five patients was allocated to a room with portable air filtration unit, however, the difference between incidence densities in rooms with and without portable air filtration units was non-significant (Fisher's exact test, P=0.33). Due to the noise level and thermal discomfort, patient compliance with the air filtration units was poor. We conclude that under field conditions this air filtration unit cannot be recommended for prevention of invasive aspergillosis in neutropenic haematology-oncology patients.

  10. Airborne exposure to inhalable hexavalent chromium in welders and other occupations: Estimates from the German MEGA database.

    PubMed

    Pesch, Beate; Kendzia, Benjamin; Hauptmann, Kristin; Van Gelder, Rainer; Stamm, Roger; Hahn, Jens-Uwe; Zschiesche, Wolfgang; Behrens, Thomas; Weiss, Tobias; Siemiatycki, Jack; Lavoué, Jerome; Jöckel, Karl-Heinz; Brüning, Thomas

    2015-07-01

    This study aimed to estimate occupational exposure to inhalable hexavalent chromium (Cr(VI)) using the exposure database MEGA. The database has been compiling Cr(VI) concentrations and ancillary data about measurements at German workplaces. We analysed 3659 personal measurements of inhalable Cr(VI) collected between 1994 and 2009. Cr(VI) was determined spectrophotometrically at 540 nm after reaction with diphenylcarbazide. We assigned the measurements to pre-defined at-risk occupations using the information provided about the workplaces. Two-thirds of the measurements were below the limit of quantification (LOQ) and multiply imputed according to the distribution above LOQ. The 75th percentile value was 5.2 μg/m(3) and the 95th percentile was 57.2 μg/m(3). We predicted the geometric mean for 2h sampling in the year 2000, and the time trend of Cr(VI) exposure in these settings with and without adjustment for the duration of measurements. The largest dataset was available for welding (N = 1898), which could be further detailed according to technique. The geometric means were above 5 μg/m(3) in the following situations: spray painting, shielded metal arc welding, and flux-cored arc welding if applied to stainless steel. The geometric means were between 1 μg/m(3) and 5 μg/m(3) for gas metal arc welding of stainless steel, cutting, hard-chromium plating, metal spraying and in the chemical chromium industry. The exposure profiles described here are useful for epidemiologic and industrial health purposes. Exposure to Cr(VI) varies not only between occupations, but also within occupations as shown for welders. In epidemiologic studies, it would be desirable to collect exposure-specific information in addition to the job title.

  11. Airborne exposure to inhalable hexavalent chromium in welders and other occupations: Estimates from the German MEGA database.

    PubMed

    Pesch, Beate; Kendzia, Benjamin; Hauptmann, Kristin; Van Gelder, Rainer; Stamm, Roger; Hahn, Jens-Uwe; Zschiesche, Wolfgang; Behrens, Thomas; Weiss, Tobias; Siemiatycki, Jack; Lavoué, Jerome; Jöckel, Karl-Heinz; Brüning, Thomas

    2015-07-01

    This study aimed to estimate occupational exposure to inhalable hexavalent chromium (Cr(VI)) using the exposure database MEGA. The database has been compiling Cr(VI) concentrations and ancillary data about measurements at German workplaces. We analysed 3659 personal measurements of inhalable Cr(VI) collected between 1994 and 2009. Cr(VI) was determined spectrophotometrically at 540 nm after reaction with diphenylcarbazide. We assigned the measurements to pre-defined at-risk occupations using the information provided about the workplaces. Two-thirds of the measurements were below the limit of quantification (LOQ) and multiply imputed according to the distribution above LOQ. The 75th percentile value was 5.2 μg/m(3) and the 95th percentile was 57.2 μg/m(3). We predicted the geometric mean for 2h sampling in the year 2000, and the time trend of Cr(VI) exposure in these settings with and without adjustment for the duration of measurements. The largest dataset was available for welding (N = 1898), which could be further detailed according to technique. The geometric means were above 5 μg/m(3) in the following situations: spray painting, shielded metal arc welding, and flux-cored arc welding if applied to stainless steel. The geometric means were between 1 μg/m(3) and 5 μg/m(3) for gas metal arc welding of stainless steel, cutting, hard-chromium plating, metal spraying and in the chemical chromium industry. The exposure profiles described here are useful for epidemiologic and industrial health purposes. Exposure to Cr(VI) varies not only between occupations, but also within occupations as shown for welders. In epidemiologic studies, it would be desirable to collect exposure-specific information in addition to the job title. PMID:25979374

  12. Urinary biomarkers of exposure and of oxidative damage in children exposed to low airborne concentrations of benzene.

    PubMed

    Andreoli, R; Spatari, G; Pigini, D; Poli, D; Banda, I; Goldoni, M; Riccelli, M G; Petyx, M; Protano, C; Vitali, M; Barbaro, M; Mutti, A

    2015-10-01

    The aim of this work was to evaluate the oxidative damage to nucleic acids in children (5-11 years) associated with exposure to environmental pollutants and tobacco smoke (ETS). For each subject, urinary sampling was done twice (evening and next morning) to measure by tandem LC-MS-MS such oxidated products of nucleic acids as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and 8-oxo-7,8-dihydroguanine (8-oxoGua). Methyl tert-butyl ether (U-MTBE), benzene (U-Benz), and its metabolites (t,t-muconic and S-phenylmercapturic acids, t,t-MA and S-PMA, respectively) were determined as biomarkers of exposure to air pollution, and cotinine as a biomarker of exposure to ETS. Biomarkers of exposure (S-PMA and U-MTBE) and of DNA oxidation (8-oxodGuo) were dependent on the urbanization and industrialization levels and increased in the evening sample as compared to next morning (p<0.05). In both evening and next morning samples, 8-oxodGuo and 8-oxoGuo correlated with each other (r=0.596 and r=0.537, respectively, p<0.01) and with biomarkers of benzene exposure, particularly S-PMA (r=0.59 and r=0.45 for 8-oxodGuo and r=0.411 and r=0.383 for 8-oxoGuo, p<0.01). No such correlations were observed for U-MTBE and cotinine. Multiple linear regression analyses showed that 8-oxodGuo was positively associated with S-PMA at both sampling times (β=0.18 and β=0.14 for evening and next morning sampling, respectively; p<0.02) and weakly with U-MTBE (β=0.07, p=0.020) only in the evening urines. These results suggest that the selected biomarkers of exposure to benzene, particularly S-PMA, are good tracers of exposure to complex mixtures of oxidative pollutants and that the associated oxidative damage to nucleic acids is detectable even at very low levels of exposure.

  13. Source Attribution of Personal Exposure to Airborne Polycyclic Aromatic Hydrocarbon Mixture Using Concurrent Personal, Indoor, and Outdoor Measurements

    PubMed Central

    Choi, Hyunok; Spengler, John

    2014-01-01

    Objectives Relative importance of multiple indoor and outdoor venues on personal exposure concentrations to pro-carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) remains poorly understood. This is particularly challenging because many c-PAHs share sources and occur as a complex mixture. Accurate and precise apportionment of personal exposure according to exposure venues could aid in understanding of human health effects due to given source. Here, we partitioned indoor and personal exposure concentrations to seven c-PAHs and pyrene according to the indoor- and outdoor- origins. Methods A simultaneous, integrated monitoring of personal, indoor and outdoor concentrations of nine PAHs was conducted in 75 homes for a consecutive 48-hour period across a two-year period in Kraków, Poland. Due to few known indoor sources for chrysene, we used this PAH species as a tracer for infiltration of outdoor PAHs. Personal and indoor concentrations of seven c-PAHs and pyrene were apportioned to home indoor, non-home indoor and outdoor origin. Results Using Chrysenein / Chryseneout as proxy for an infiltration factor, Finf, infiltrated PAHs of outdoor origin are overall higher in concentration than those emitted from the indoor origin. Average contribution by the outdoor sources on B[a]A, B[b]F, and B[k]F were 92%, 79%, and 78% across all seasons. In contrast, in homes where a household members smoked, average contribution by the outdoor sources on B[ghi]P, B[a]P, D[ah]A, and IP were lower (i.e., 67%, 65%, 67%, and 66%, respectively). Season-averaged contribution by the outdoor sources on personal exposure to B[a]A, B[b]F, and B[k]F were 92%, 74%, and 77%, respectively. On the other hand, season-averaged home indoor source contribution on personal exposure to B[a]A, B[b]F, and B[k]F were estimated at 6%, 15%, and 19%, respectively. Similar contributions by season-averaged home indoor sources on personal exposure were estimated at 28% for B[ghi]P, 31% for B[a]P, 25% for D

  14. Addressing endotoxin issues in bioengineered heparin.

    PubMed

    Suwan, Jiraporn; Torelli, Amanda; Onishi, Akihiro; Dordick, Jonathan S; Linhardt, Robert J

    2012-01-01

    Heparin is a widely used clinical anticoagulant that is prepared from pig intestine. A contamination of heparin in 2008 has led to a reexamination of animal-derived pharmaceuticals. A bioengineered heparin prepared by bacterial fermentation and chemical and enzymatic processing is currently under development. This study examines the challenges of reducing or removing endotoxins associated with this process that are necessary to proceed with preclinical in vivo evaluation of bioengineered heparin. The current process is assessed for endotoxin levels, and strategies are examined for endotoxin removal from polysaccharides and enzymes involved in this process. PMID:23586950

  15. Metal ions potentiate microglia responsiveness to endotoxin.

    PubMed

    Rachmawati, Dessy; Peferoen, Laura A N; Vogel, Daphne Y S; Alsalem, Inás W A; Amor, Sandra; Bontkes, Hetty J; von Blomberg, B Mary E; Scheper, Rik J; van Hoogstraten, Ingrid M W

    2016-02-15

    Oral metal exposure has been associated with diverse adverse reactions, including neurotoxicity. We showed previously that dentally applied metals activate dendritic cells (MoDC) via TLR4 (Ni, Co, Pd) and TLR3 (Au). It is still unknown whether the low levels of dental metals reaching the brain can trigger local innate cells or prime them to become more responsive. Here we tested whether dentally applied metals (Cr, Fe, Co, Ni, Cu, Zn, Au, Hg) activate primary human microglia in vitro and, as a model, monocytic THP-1-cells, in high non-toxic as well as near-physiological concentrations. In addition the effects of 'near-physiological' metal exposure on endotoxin (LPS) responsiveness of these cells were evaluated. IL-8 and IL-6 production after 24h was used as read out. In high, non-toxic concentrations all transition metals except Cr induced IL-8 and IL-6 production in microglia, with Ni and Co providing the strongest stimulation. When using near-physiological doses (up to 10× the normal plasma concentration), only Zn and Cu induced significant IL-8 production. Of note, the latter metals also markedly potentiated LPS responsiveness of microglia and THP-1 cells. In conclusion, transition metals activate microglia similar to MoDCs. In near-physiological concentrations Zn and Cu are the most effective mediators of innate immune activation. A clear synergism between innate responses to Zn/Cu and LPS was observed, shedding new light on the possible relation between oral metal exposure and neurotoxicity.

  16. Exposure to Phthalate Emitted from Vinyl Flooring and Sorbed to Interior Surfaces, Dust, Airborne Particles and Human Skin

    EPA Science Inventory

    There is an urgent need to characterize potential risk to human health and the environment that arises from the manufacture and use of tens of thousands of chemicals. Computational tools and approaches for characterizing and prioritizing exposure are required: to provide input f...

  17. Linking Endotoxins, African Dust PM10 and Asthma in an Urban and Rural Environment of Puerto Rico

    PubMed Central

    Ortiz-Martínez, Mario G.; Rodríguez-Cotto, Rosa I.; Ortiz-Rivera, Mónica A.; Pluguez-Turull, Cedric W.; Jiménez-Vélez, Braulio D.

    2015-01-01

    African Dust Events (ADE) are a seasonal phenomenon that has been suggested to exacerbate respiratory and proinflammatory diseases in Puerto Rico (PR). Increases in PM10 concentration and the effects of biological endotoxins (ENX) are critical factors to consider during these storms. ENX promote proinflammatory responses in lungs of susceptible individuals through activation of the Toll-like receptors (TLR2/4) signaling pathways. The objective of the study was to evaluate the toxicological and proinflammatory responses stimulated by ADE PM10 ENX reaching PR using human bronchial epithelial cells. PM10 organic extracts from a rural and urban site in PR (March 2004) were obtained from ADE and non-ADE and compared. A retrospective data analysis (PM10 concentration, aerosol images, and pediatric asthma claims) was performed from 2000 to 2012 with particular emphasis in 2004 to classify PM samples. Urban extracts were highly toxic, proinflammatory (IL-6/IL-8 secretion), and induced higher TLR4 expression and NF-κB activation compared to rural extracts. ENX were found to contribute to cytotoxicity and inflammatory responses provoked by urban ADE PM10 exposure suggesting a synergistic potency of local and natural ENX incoming from ADE. The contribution of ADE PM10 ENX is valuable in order to understand interactions and action mechanisms of airborne pollutants as asthma triggers in PR. PMID:26681839

  18. Development of a dose-controlled multiculture cell exposure chamber for efficient delivery of airborne and engineered nanoparticles

    NASA Astrophysics Data System (ADS)

    Asimakopoulou, Akrivi; Daskalos, Emmanouil; Lewinski, Nastassja; Riediker, Michael; Papaioannou, Eleni; Konstandopoulos, Athanasios G.

    2013-04-01

    In order to study the various health influencing parameters related to engineered nanoparticles as well as to soot emitted by Diesel engines, there is an urgent need for appropriate sampling devices and methods for cell exposure studies that simulate the respiratory system and facilitate associated biological and toxicological tests. The objective of the present work was the further advancement of a Multiculture Exposure Chamber (MEC) into a dose-controlled system for efficient delivery of nanoparticles to cells. It was validated with various types of nanoparticles (Diesel engine soot aggregates, engineered nanoparticles for various applications) and with state-of-the-art nanoparticle measurement instrumentation to assess the local deposition of nanoparticles on the cell cultures. The dose of nanoparticles to which cell cultures are being exposed was evaluated in the normal operation of the in vitro cell culture exposure chamber based on measurements of the size specific nanoparticle collection efficiency of a cell free device. The average efficiency in delivering nanoparticles in the MEC was approximately 82%. The nanoparticle deposition was demonstrated by Transmission Electron Microscopy (TEM). Analysis and design of the MEC employs Computational Fluid Dynamics (CFD) and true to geometry representations of nanoparticles with the aim to assess the uniformity of nanoparticle deposition among the culture wells. Final testing of the dose-controlled cell exposure system was performed by exposing A549 lung cell cultures to fluorescently labeled nanoparticles. Delivery of aerosolized nanoparticles was demonstrated by visualization of the nanoparticle fluorescence in the cell cultures following exposure. Also monitored was the potential of the aerosolized nanoparticles to generate reactive oxygen species (ROS) (e.g. free radicals and peroxides generation), thus expressing the oxidative stress of the cells which can cause extensive cellular damage or damage on DNA.

  19. Health risk equations and risk assessment of airborne benzene homologues exposure to drivers and passengers in taxi cabins.

    PubMed

    Chen, Xiaokai; Feng, Lili; Luo, Huilong; Cheng, Heming

    2016-03-01

    Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m(3)) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.

  20. Health implications of lipopolysaccharide endotoxins in domestic container water used by rural households in South Africa.

    PubMed

    Fosso-Kankeu, E; Du Preez, H; Jagals, P

    2010-12-01

    This study assessed the occurrence of endotoxins, cyanobacteria and enterobacteria in untreated drinking water stored in domestic water containers by rural households in South Africa. Endotoxins, cyanobacteria, total coliforms and Escherichia coli were measured in the following numbers and ranges in container-water samples: 4-54 microg l(-1), 69-64,505 cells ml(-1), 9,000-280,000 CFU/100 ml and 90-1,100 CFU/100 ml, respectively, in source water and 0.23-24.7 microg l(-1), 1-501,187 cells ml(-1), 25-1,584,893 CFU/100 ml and 1-25,118 CFU/100 ml, respectively, in water from containers. The concentrations of these contaminants in water often exceeded guidelines. Container type, especially those that permit light into the vessel, played a significant role in the occurrence of these contaminants. Limited guidelines, as well as the absence of health evidence, make it uncertain whether the high levels of endotoxins in the containerised drinking water could cause a health effect in healthy persons. Most importantly, in the context of exposure to endotoxins potentially derived from high levels of cyanobacteria and enterobacteria such as coliforms in the water, a case is made for possible health effects in immune-compromised individuals exposed to water containing endotoxins and the bacteria that potentially produce it.

  1. Use of a robotic sampling platform to assess young children's exposure to indoor bioaerosols

    PubMed Central

    Wang, Zuocheng; Shalat, Stuart L.; Black, Kathleen; Lioy, Paul J.; Stambler, Adam A.; Emoekpere, Osiloke H.; Hernandez, Marta; Han, Taewon; Ramagopal, Maya; Mainelis, Gediminas

    2011-01-01

    Indoor exposures to allergens, mold spores and endotoxin have been suggested as etiological agents of asthma; therefore, accurate determination of those exposures, especially in young children (6–36 months), is important for understanding the development of asthma. Since use of personal sampling equipment in this population is difficult, and in children < 1 year of age impossible, we developed a personal sampling surrogate: the Pretoddler Inhalable Particulate Environmental Robotic sampler (PIPER) to better estimate their exposures. During sampling, PIPER simulates the activity patterns, speed of motion and the height of the breathing zones of young children, and mechanically resuspends the deposited dust just as a young child does during running and crawling. The concentrations of allergens, mold spores and endotoxin measured by PIPER were compared to those measured using traditional stationary air sampling in 75 homes in central New Jersey, US. Endotoxin was detected in all homes with median concentrations of 1.0 and 0.55 EU/m3 for PIPER and stationary sampler, respectively. The difference in median concentrations obtained using the two methods was statistically significant for homes with carpeted floors (p= 0.0001) in the heating season. For such homes, the average ratio of endotoxin concentration measured by PIPER and the stationary sampler was 2.96 (95% CI 2.29–3.63). Fungal spores were detected in all homes, with median fungal concentrations of 316 and 380 spores/m3 for PIPER and stationary sampler, respectively. For fungi, the difference between the two sampling methods was not statistically significant. For both sampling methods, the total airborne mold levels were statistically significantly higher in the non-heating season than in the heating season. Allergens were detected in ~15% of investigated homes. The data indicate that the traditional stationary air sampling methods may substantially underestimate personal exposures to endotoxin, especially

  2. Air Pollution and Stillbirth Risk: Exposure to Airborne Particulate Matter during Pregnancy Is Associated with Fetal Death

    PubMed Central

    DeFranco, Emily; Hall, Eric; Hossain, Monir; Chen, Aimin; Haynes, Erin N.; Jones, David; Ren, Sheng; Lu, Long; Muglia, Louis

    2015-01-01

    Objective To test the hypothesis that exposure to fine particulate air pollution (PM2.5) is associated with stillbirth. Study Design Geo-spatial population-based cohort study using Ohio birth records (2006-2010) and local measures of PM2.5, recorded by the EPA (2005-2010) via 57 monitoring stations across Ohio. Geographic coordinates of the mother’s residence for each birth were linked to the nearest PM2.5 monitoring station and monthly exposure averages calculated. The association between stillbirth and increased PM2.5 levels was estimated, with adjustment for maternal age, race, education level, quantity of prenatal care, smoking, and season of conception. Results There were 349,188 live births and 1,848 stillbirths of non-anomalous singletons (20-42 weeks) with residence ≤10 km of a monitor station in Ohio during the study period. The mean PM2.5 level in Ohio was 13.3 μg/m3 [±1.8 SD, IQR(Q1: 12.1, Q3: 14.4, IQR: 2.3)], higher than the current EPA standard of 12 μg/m3. High average PM2.5 exposure through pregnancy was not associated with a significant increase in stillbirth risk, adjOR 1.21(95% CI 0.96,1.53), nor was it increased with high exposure in the 1st or 2nd trimester. However, exposure to high levels of PM2.5 in the third trimester of pregnancy was associated with 42% increased stillbirth risk, adjOR 1.42(1.06,1.91). Conclusions Exposure to high levels of fine particulate air pollution in the third trimester of pregnancy is associated with increased stillbirth risk. Although the risk increase associated with high PM2.5 levels is modest, the potential impact on overall stillbirth rates could be robust as all pregnant women are potentially at risk. PMID:25794052

  3. Use of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research

    PubMed Central

    MAXWELL, SUSAN K.; MELIKER, JAYMIE R.; GOOVAERTS, PIERRE

    2015-01-01

    In recent years, geographic information systems (GIS) have increasingly been used for reconstructing individual-level exposures to environmental contaminants in epidemiological research. Remotely sensed data can be useful in creating space-time models of environmental measures. The primary advantage of using remotely sensed data is that it allows for study at the local scale (e.g., residential level) without requiring expensive, time-consuming monitoring campaigns. The purpose of our study was to identify how land surface remotely sensed data are currently being used to study the relationship between cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessment applications. We present the results of a comprehensive literature review of epidemiological research where remotely sensed imagery or land cover maps derived from remotely sensed imagery were applied. We also discuss the strengths and limitations of the most commonly used imagery data (aerial photographs and Landsat satellite imagery) and land cover maps. PMID:19240763

  4. Use of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research

    USGS Publications Warehouse

    Maxwell, S.K.; Meliker, J.R.; Goovaerts, P.

    2010-01-01

    In recent years, geographic information systems (GIS) have increasingly been used for reconstructing individual-level exposures to environmental contaminants in epidemiological research. Remotely sensed data can be useful in creating space-time models of environmental measures. The primary advantage of using remotely sensed data is that it allows for study at the local scale (e.g., residential level) without requiring expensive, time-consuming monitoring campaigns. The purpose of our study was to identify how land surface remotely sensed data are currently being used to study the relationship between cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessment applications. We present the results of a comprehensive literature review of epidemiological research where remotely sensed imagery or land cover maps derived from remotely sensed imagery were applied. We also discuss the strengths and limitations of the most commonly used imagery data (aerial photographs and Landsat satellite imagery) and land cover maps. ?? 2010 Nature Publishing Group All rights reserved.

  5. The role of endotoxin in grain dust-induced lung disease.

    PubMed

    Schwartz, D A; Thorne, P S; Yagla, S J; Burmeister, L F; Olenchock, S A; Watt, J L; Quinn, T J

    1995-08-01

    To identify the role of endotoxin in grain dust-induced lung disease, we conducted a population-based, cross-sectional investigation among grain handlers and postal workers. The study subjects were selected by randomly sampling all grain facilities and post offices within 100 miles of Iowa City. Our study population consisted of 410 grain workers and 201 postal workers. Grain workers were found to be exposed to higher concentrations of airborne dust (p = 0.0001) and endotoxin (p = 0.0001) when compared with postal workers. Grain workers had a significantly higher prevalence of work-related (cough, phlegm, wheezing, chest tightness, and dyspnea) and chronic (usual cough or phlegm production) respiratory symptoms than postal workers. Moreover, after controlling for age, gender, and cigarette smoking status, work-related respiratory symptoms were strongly associated with the concentration of endotoxin in the bioaerosol in the work setting. The concentration of total dust in the bioaerosol was marginally related to these respiratory problems. After controlling for age, gender, and cigarette smoking status, grain workers were found to have reduced spirometric measures of airflow (FEV1, FEV1/FVC, and FEF25-75) and enhanced airway reactivity to inhaled histamine when compared with postal workers. Although the total dust concentration in the work environment appeared to have little effect on these measures of airflow obstruction, higher concentrations of endotoxin in the bioaerosol were associated with diminished measures of airflow and enhanced bronchial reactivity. Our results indicate that the concentration of endotoxin in the bioaerosol may be particularly important in the development of grain dust-induced lung disease. PMID:7633714

  6. Coal miners' mortality in relaton to radiological category, lung function and exposure to airborne dust. Final report

    SciTech Connect

    Miller, B.G.; Jacobsen, M.; Steele, R.C.

    1981-06-01

    This report describes mortality among 29,553 British coal miners. They represent 93.5% of 31,611 men who were surveyed radiologically at 24 coal mines in the period 1953 through 1958. The main aim of the work was to consider risks of death attributed to various underlying causes, as recorded on death certificates, in relation to radiological signs of pneumoconiosis, measures of lung function, and exposure to respirable coal mine dust.

  7. Subchronic inhalation exposure study of an airborne polychlorinated biphenyl (PCB) mixture resembling the Chicago ambient air congener profile

    PubMed Central

    Hu, Xin; Adamcakova-Dodd, Andrea; Lehmler, Hans-Joachim; Hu, Dingfei; Hornbuckle, Keri; Thorne, Peter S

    2013-01-01

    Although inhalation of atmospheric PCBs is the most universal exposure route and has become a substantial concern in urban areas, research is lacking to determine the body burden of inhaled PCBs and consequent health effects. To reflect the Chicago airshed environment and mimic the PCB profile in Chicago air, we generated vapors from a Chicago Air Mixture (CAM). Sprague-Dawley rats were exposed to the CAM vapor for 1.6 hr/day via nose-only inhalation for 4 wks, 520±10 μg/m3. Congener-specific quantification in tissue and air samples was performed by GC/MS/MS. In contrast to the lower-chlorinated congener enriched vapor, body tissues mainly contained tri- to hexachlorobiphenyls. Congener profiles varied between vapor and tissues, and among different organs. The toxic equivalence (TEQ) and neurotoxic equivalence (NEQ) were also investigated for tissue distribution. We evaluated a variety of endpoints to catalog the effects of long-term inhalation exposure, including immune responses, enzyme induction, cellular toxicity and histopathologic abnormalities. GSSG/GSH ratio was increased in blood of exposed animals, accompanied by elevation of hematocrit. This study demonstrated that inhalation contributed to the body burden of mostly tri- to hexachlorobiphenyls and produced a distinct profile of congeners in tissue, yet minimal toxicity was found at this exposure dose estimated at 134 μg/rat. PMID:22846166

  8. Citalopram reduces endotoxin-induced fatigue.

    PubMed

    Hannestad, Jonas; DellaGioia, Nicole; Ortiz, Nyrma; Pittman, Brian; Bhagwagar, Zubin

    2011-02-01

    Increased levels of inflammatory cytokines such as tumor necrosis factor (TNF) and interleukin-6 (IL-6) may play a role in depression. Mild depressive-like symptoms can be induced in humans through activation of the innate immune system with endotoxin. Whether preventive treatment with antidepressants can reduce endotoxin-induced symptoms has never been tested. In a double-blind, randomized, placebo-controlled, cross-over study, we administered intravenous low-dose endotoxin (0.8 ng/kg) or placebo to 11 healthy subjects who had received oral pre-treatment with citalopram (10 mg twice a day) or placebo for 5 days. The Montgomery-Åsberg Depression Rating Scale, the State and Trait Anxiety Inventory, and a visual analog scale were used to measure depressive and anxiety symptoms and social anhedonia. Serum levels of TNF and IL-6 were measured with immunoassays. Compared to placebo, endotoxin administration increased serum levels of TNF and IL-6, and caused mild depressive-like symptoms, in particular lassitude and social anhedonia. While citalopram pre-treatment had no effect on the innate immune response to endotoxin, it reduced the endotoxin-induced MADRS total score by 50%, with a moderate effect size (Cohen's d=0.5). Most of the MADRS total score was due to the lassitude item, and citalopram pre-treatment specifically reduced endotoxin-induced lassitude with a large effect size (Cohen's d=0.9). These results suggest that subchronic pre-treatment with the serotonin-reuptake inhibitor citalopram blunts mood symptoms induced by acute immune system activation with endotoxin without inhibiting the peripheral immune response.

  9. Identification of risk factors for sub-optimal housing conditions in Australian piggeries: Part 2. Airborne pollutants.

    PubMed

    Banhazi, T M; Seedorf, J; Rutley, D L; Pitchford, W S

    2008-01-01

    The concentrations of total airborne bacteria, respirable endotoxins, ammonia, and respirable and inhalable particles were monitored in 160 piggery buildings in Australia between autumn 1997 and autumn 1999. The overall mean airborne bacteria, respirable endotoxins, ammonia (NH3), and inhalable and respirable particle concentrations measured were 1.17 x 10(5) cfu m(-3), 33.1 EU m(-3), 3.7 ppm, 1.74 mg m(-3), and 0.26 mg m(-3), respectively. The characteristics of the buildings and management systems used were documented at the time of sampling. A multifactorial general linear model (GLM) statistical procedure was used to analyze the effects of housing and management factors on the concentrations of the airborne pollutants. Both airborne bacteria and respirable endotoxin concentrations were affected by building classification (type), and respirable endotoxin concentrations were positively correlated with increasing humidity. The concentrations of airborne bacteria increased as the level of pen hygiene (cleanliness) decreased. The NH3 concentrations were primarily affected by level of pen hygiene, building volume, pig flow management, and season. Building classification, pig flow management, season, building volume, ventilation rates, and temperature affected inhalable particle concentrations. Respirable particle concentrations were primarily affected by building classification, pen hygiene, pig flow management, season, ventilation rates, temperature, and humidity. These findings suggest that environmental improvement strategies (such as improved cleaning, ventilation, and temperature control) are likely to reduce airborne pollutant concentrations in pig buildings and in the environment, thus improving the health and welfare of both pigs and farm staff.

  10. Airborne Transparencies.

    ERIC Educational Resources Information Center

    Horne, Lois Thommason

    1984-01-01

    Starting from a science project on flight, art students discussed and investigated various means of moving in space. Then they made acetate illustrations which could be used as transparencies. The projection phenomenon made the illustrations look airborne. (CS)

  11. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    PubMed

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure. PMID:26233734

  12. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    PubMed

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure.

  13. Exposure to airborne particles and volatile organic compounds from polyurethane molding, spray painting, lacquering, and gluing in a workshop.

    PubMed

    Mølgaard, Bjarke; Viitanen, Anna-Kaisa; Kangas, Anneli; Huhtiniemi, Marika; Larsen, Søren Thor; Vanhala, Esa; Hussein, Tareq; Boor, Brandon E; Hämeri, Kaarle; Koivisto, Antti Joonas

    2015-04-02

    Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs) in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC) concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo-ionization detector measurements. The mean working-hour particle number concentration varied between locations from 3000 to 36,000 cm-3. Analysis of temporal and spatial variations of TVOC concentrations revealed that there were at least four substantial VOC sources: spray gluing, mold-release agent spraying, continuous evaporation from various lacquer and paint containers, and either spray painting or lacquering (probably both). The mold-release agent spray was indirectly also a major source of ultrafine particles. The workers' exposure can be reduced by improving the local exhaust ventilation at the known sources and by increasing the ventilation rate in the area with the continuous source.

  14. Exposure to Airborne Particles and Volatile Organic Compounds from Polyurethane Molding, Spray Painting, Lacquering, and Gluing in a Workshop

    PubMed Central

    Mølgaard, Bjarke; Viitanen, Anna-Kaisa; Kangas, Anneli; Huhtiniemi, Marika; Larsen, Søren Thor; Vanhala, Esa; Hussein, Tareq; Boor, Brandon E.; Hämeri, Kaarle; Koivisto, Antti Joonas

    2015-01-01

    Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs) in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC) concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo-ionization detector measurements. The mean working-hour particle number concentration varied between locations from 3000 to 36,000 cm−3. Analysis of temporal and spatial variations of TVOC concentrations revealed that there were at least four substantial VOC sources: spray gluing, mold-release agent spraying, continuous evaporation from various lacquer and paint containers, and either spray painting or lacquering (probably both). The mold-release agent spray was indirectly also a major source of ultrafine particles. The workers’ exposure can be reduced by improving the local exhaust ventilation at the known sources and by increasing the ventilation rate in the area with the continuous source. PMID:25849539

  15. Microbial Exposure Assessment in Sawmill, Livestock Feed Industry, and Metal Working Fluids Handling Industry

    PubMed Central

    Park, Haedong; Lee, Inseop

    2010-01-01

    Objectives The objective of this study is to investigate the distribution patterns and exposure concentrations of bioaerosols in industries suspected to have high levels of bioaerosol exposure. Methods We selected 11 plants including 3 livestock feed plants (LF industry), 3 metal working fluids handling plants (MWFs industry), and 5 sawmills and measured total airborne bacteria, fungi, endotoxins, as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage cascade impactor, and gelatin filters. Endotoxins were measured with polycarbonate filters. Results The geometric means (GM) of the airborne concentrations of bacteria, fungi, and endotoxins were 1,864, 2,252 CFU/m3, and 31.5 EU/m3, respectively at the sawmills, followed by the LF industry (535, 585 CFU/m3, and 22.0 EU/m3) and MWFs industry (258, 331 CFU/m3, and 8.7 EU/m3). These concentrations by industry type were significantly statistically different (p < 0.01). The ratio of indoor to outdoor concentration was 6.2, 1.9, 3.2, and 3.2 for bacteria, fungi, endotoxins, and dust in the LF industry, 5.0, 0.9, 2.3, and 12.5 in the MWFs industry, and 3.7, 4.1, 3.3, and 9.7 in sawmills. The respiratory fractions of bioaerosols were differentiated by bioaerosol types and industry types: the respiratory fraction of bacteria in the LF industry, MWF industry, and sawmills was 59.4%, 72.0%, and 57.7%, respectively, and that of fungi was 77.3%, 89.5%, and 83.7% in the same order. Conclusion We found that bioaerosol concentration was the highest in sawmills, followed by LF industry facilities and MWFs industry facilities. The indoor/outdoor ratio of microorganisms was larger than 1 and respiratory fraction of microorganisms was more than 50% of the total microorganism concentrations which might penetrate respiratory tract easily. All these findings suggest that bioaerosol in the surveyed industries should be controlled to prevent worker respiratory diseases. PMID:22953179

  16. Predictors of coarse particulate matter and associated endotoxin concentrations in residential environments

    NASA Astrophysics Data System (ADS)

    Bari, Md. Aynul; MacNeill, Morgan; Kindzierski, Warren B.; Wallace, Lance; Héroux, Marie-Ève; Wheeler, Amanda J.

    2014-08-01

    Exposure to coarse particulate matter (PM), i.e., particles with an aerodynamic diameter between 2.5 and 10 μm (PM10-2.5), is of increasing interest due to the potential for health effects including asthma, allergy and respiratory symptoms. Limited information is available on indoor and outdoor coarse PM and associated endotoxin exposures. Seven consecutive 24-h samples of indoor and outdoor coarse PM were collected during winter and summer 2010 using Harvard Coarse Impactors in a total of 74 Edmonton homes where no reported smoking took place. Coarse PM filters were subsequently analyzed for endotoxin content. Data were also collected on indoor and outdoor temperature, relative humidity, air exchange rate, housing characteristics and occupants' activities. During winter, outdoor concentrations of coarse PM (median = 6.7 μg/m3, interquartile range, IQR = 3.4-12 μg/m3) were found to be higher than indoor concentrations (median 3.4 μg/m3, IQR = 1.6-5.7 μg/m3); while summer levels of indoor and outdoor concentrations were similar (median 4.5 μg/m3, IQR = 2.3-6.8 μg/m3, and median 4.7 μg/m3, IQR = 2.1-7.9 μg/m3, respectively). Similar predictors were identified for indoor coarse PM in both seasons and included corresponding outdoor coarse PM concentrations, whether vacuuming, sweeping or dusting was performed during the sampling period, and number of occupants in the home. Winter indoor coarse PM predictors also included the number of dogs and indoor endotoxin concentrations. Summer median endotoxin concentrations (indoor: 0.41 EU/m3, outdoor: 0.64 EU/m3) were 4-fold higher than winter concentrations (indoor: 0.12 EU/m3, outdoor: 0.16 EU/m3). Other than outdoor endotoxin concentrations, indoor endotoxin concentration predictors for both seasons were different. Winter endotoxin predictors also included presence of furry pets and whether the vacuum had a high efficiency particulate air (HEPA) filter. Summer endotoxin predictors were problems with mice in the

  17. Sex differences in hypothalamic-pituitary-adrenal responding to endotoxin challenge in the neonate: reversal by gonadectomy.

    PubMed

    Shanks, N; McCormick, C M; Meaney, M J

    1994-06-17

    Exposure to endotoxin is known to activate hypothalamic-pituitary-adrenal (HPA) responses in both adult and neonatal animals. We have previously reported that female rat pups exhibit greater HPA responses to endotoxin challenge than males. It is unclear, however, whether observed gender differences at this early age are mediated by gonadal factors. In the present investigation we assessed the effects of neonatal gonadectomy on HPA responses to endotoxin challenge in the developing rat. On the first day of life Long-Evans rat pups were gonadectomized or subjected to sham surgery. On the third day of life the pups were injected i.p. with 0.05 mg/kg Salmonella enteritidis endotoxin. Four hours following injection, trunk blood and tissues were collected for determination of plasma hormones and median eminence corticotropin-releasing hormone (CRH) content. Intact female rat pups were found to exhibit greater plasma adrenocorticotrophic hormone (ACTH) and corticosterone responses to endotoxin challenge compared with male animals. Plasma corticosterone levels, both total and free steroid, were markedly altered by removal of gonads such that responding to endotoxin was elevated in males, while it was reduced in females. In contrast, ACTH responding in male pups was not altered following gonadectomy, whereas female ACTH responses were significantly reduced compared with endotoxin-treated intact controls. CRH levels in the median eminence were reduced following endotoxin challenge to an equivalent extent in both male and female pups and this effect was partially attenuated by the removal of gonadal hormones. These data suggest that sex differences in HPA responses to immune challenge may be mediated at different levels of the HPA axis.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Network Topologies and Dynamics Leading to Endotoxin Tolerance and Priming in Innate Immune Cells

    NASA Astrophysics Data System (ADS)

    Fu, Yan; Glaros, Trevor; Zhu, Meng; Wang, Ping; Wu, Zhanghan; Tyson, John; Li, Liwu; Xing, Jianhua

    2012-01-01

    The innate immune system, acting as the first line of host defense, senses and adapts to foreign challenges through complex intracellular and intercellular signaling networks. Endotoxin tolerance and priming elicited by macrophages are classic examples of the complex adaptation of innate immune cells. Upon repetitive exposures to different doses of bacterial endotoxin (lipopolysaccharide) or other stimulants, macrophages show either suppressed or augmented inflammatory responses compared to a single exposure to the stimulant. Endotoxin tolerance and priming are critically involved in both immune homeostasis and the pathogenesis of diverse inflammatory diseases. However, the underlying molecular mechanisms are not well understood. By means of a computational search through the parameter space of a coarse-grained three-node network with a two-stage Metropolis sampling approach, we enumerated all the network topologies that can generate priming or tolerance. We discovered three major mechanisms for priming (pathway synergy, suppressor deactivation, activator induction) and one for tolerance (inhibitor persistence). These results not only explain existing experimental observations, but also reveal intriguing test scenarios for future experimental studies to clarify mechanisms of endotoxin priming and tolerance.

  19. Intravenous Endotoxin Challenge in Healthy Humans: An Experimental Platform to Investigate and Modulate Systemic Inflammation

    PubMed Central

    Fullerton, James N.; Segre, Elisabetta; De Maeyer, Roel P.H.; Maini, Alexander A.N.; Gilroy, Derek W.

    2016-01-01

    Activation of inflammatory pathways represents a central mechanism in multiple disease states both acute and chronic. Triggered via either pathogen or tissue damage-associated molecular motifs, common biochemical pathways lead to conserved yet variable physiological and immunological alterations. Dissection and delineation of the determinants and mechanisms underlying phenotypic variance in response is expected to yield novel therapeutic advances. Intravenous (IV) administration of endotoxin (gram-negative bacterial lipopolysaccharide), a specific Toll-like receptor 4 agonist, represents an in vivo model of systemic inflammation in man. National Institutes for Health Clinical Center Reference Endotoxin (CCRE, Escherichia coli O:113:H10:K negative) is employed to reliably and reproducibly generate vascular, hematological, endocrine, immunological and organ-specific functional effects that parallel, to varying degrees, those seen in the early stages of pathological states. Alteration of dose (0.06 - 4 ng/kg) and time-scale of exposure (bolus vs. infusion) allows replication of either acute or chronic inflammation and a range of severity to be elicited, with higher doses (2 - 4 ng/kg) frequently being used to create a 'sepsis-like' state. Established and novel medicinal compounds may additionally be administered prior to or post endotoxin exposure to appreciate their effect on the inflammatory cascade. Despite limitations in scope and generalizability, human IV endotoxin challenge offers a unique platform to gain mechanistic insights into inducible physiological responses and inflammatory pathways. Rationally employed it may aid translation of this knowledge into therapeutic innovations. PMID:27213711

  20. In vivo effects of endotoxin on DNA synthesis in rat nasal epithelium

    SciTech Connect

    Harkema, J.R.; Hotchkiss, J.A. )

    1993-12-01

    Airway inflammation in bacterial infections is characterized by the presence of neutrophils and often epithelial injury and repair. Release of endotoxin from bacteria may contribute to these processes. The purpose of this study was to determine the in vivo effects of repeated endotoxin exposure on DNA synthesis in rat nasal epithelium in the presence and absence of neutrophilic influx. Rats were intranasally instilled, once a day for 3 days, with endotoxin or saline (controls). Before the first and third instillations, half of the saline and endotoxin-instilled animals were depleted of circulating blood neutrophils by administering a rabbit anti-rat neutrophil antiserum. Rats were sacrificed 6 or 24 h after the last instillation. Two hours prior to sacrifice, rats were intraperitoneally injected with bromodeoxyuridine (BrdU), an analog of thymidine that is incorporated in the nucleus of cells in the S-phase of the cell cycle. Nasal tissues were processed for light microscopy and immunohistochemical detection of BrdU in nasal epithelial cells. The numbers of nasal epithelial cells, BrdU-labeled epithelial nuclei, and neutrophils per millimeter of basal lamina in the epithelium lining the nasal turbinates in the proximal nasal passages were determined by morphometric analysis. The authors did not observe a neutrophilic influx in the nasal tissues of neutrophil-depleted rats at 6 or 24 h after the last endotoxin instillation; however, the numbers of nasal epithelial cells and the BrdU-labeling index were significantly increased compared to saline-instilled controls. In contrast, non-neutrophil-depleted rats instilled with endotoxin had a marked neutrophilic influx, but no significant differences in the number of nasal epithelial cells at 6 or 24 h, compared to controls. In addition, the BrdU-labeling index in neutrophil-sufficient rats was increased only 6 h after the last instillation, compared to controls.

  1. Invited review: Role of bacterial endotoxins in the etiopathogenesis of periparturient diseases of transition dairy cows.

    PubMed

    Eckel, Emily F; Ametaj, Burim N

    2016-08-01

    The dairy industry continues to suffer severe economic losses due to the increased disease incidence cows experience during the transition period. It has long been the classical view that the major contributing factor to the development of these periparturient diseases is the considerable increase in nutritional demands for milk production. This classical view, however, fails to account for the substantial correlation between both metabolic and infectious diseases and the detrimental effects that can occur with the provision of high-energy diets to support these nutritional demands. Currently, increasing evidence implicates bacterial endotoxins in the etiopathology of most periparturient diseases. Bacterial endotoxins are components of the outer cell wall of gram-negative and gram-positive bacteria that are highly immunostimulatory and can trigger proinflammatory immune responses. The ability of endotoxins to translocate from the mucosal tissues, including the gastrointestinal tract, mammary gland, and uterus, into the systemic circulation has been observed. Once they have entered the circulation, endotoxins potentially contribute to disease either directly, through eliciting an inflammatory response, or indirectly through other factors such as the overreaction of the natural protective mechanisms of the host. Although the evidence implicating a role of endotoxins in the pathogenesis of transition diseases continues to grow, our current knowledge of the host response to mucosal endotoxin exposure and pathogenic mechanisms remain largely unknown. Developing our understanding of the connection between endotoxemia and dairy cattle disease holds significant potential for the future development of preventative measures that could benefit the productivity of the dairy industry as well as animal welfare. PMID:27209132

  2. Hypo-responsiveness of interleukin-8 production in human embryonic epithelial intestine 407 cells independent of NF-{kappa}B pathway: New lessons from endotoxin and ribotoxic deoxynivalenol

    SciTech Connect

    Moon, Yuseok Yang, Hyun; Park, Seung-Hwan

    2008-08-15

    Mucosal epithelium senses external toxic insults and transmits the danger signals into the epithelial cells in order to activate a broad range of inflammatory responses. However, pre-exposure to the commensal endotoxins can induce inflammatory tolerance and maintain the homeostasis without excessive immune responses. We recently reported that ribotoxin deoxynivalenol (DON) and its derivatives elicited the pro-inflammatory response as the mucosal insults in human epithelial cells. Taking the knowledge into consideration, we tested the hypothesis that endotoxin pre-exposure can attenuate ribotoxin-induced epithelial interleukin-8 (IL-8) production via a tolerance mechanism. Pre-exposure to endotoxin repressed IL-8 release and its gene expression. However, inflammatory tolerance was not mediated by the attenuated NF-{kappa}B activation which has been generally recognized as the major mediator of LPS-mediated toll-like receptor (TLR) signaling pathway. Instead, pre-exposure to endotoxin was observed to trigger the delayed induction of peroxisome proliferator-activated receptor gamma (PPAR-{gamma}) which contributed to the diminished IL-8 production in the human epithelial cells. Moreover, endogenous PPAR-{gamma} agonist suppressed toxicant-mediated interleukin-8 production and IL-8 mRNA stability. Taken together, endotoxin induced hypo-production of pro-inflammatory cytokine IL-8 in the human epithelial cells, which was associated with the delayed activation of PPAR-{gamma} expression by pre-existing endotoxin.

  3. Indoor-biofilter growth and exposure to airborne chemicals drive similar changes in plant root bacterial communities.

    PubMed

    Russell, Jacob A; Hu, Yi; Chau, Linh; Pauliushchyk, Margarita; Anastopoulos, Ioannis; Anandan, Shivanthi; Waring, Michael S

    2014-08-01

    Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean indoor air of harmful volatile organic compounds (VOCs), which are typically found at concentrations higher indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or biowalls, converting VOCs into biomass, energy, and carbon dioxide, but little is known about the root microbial communities of such artificially grown plants, how or whether they differ from those of plants grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigated how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through 16S rRNA amplicon sequencing, we compared root bacterial communities from soil-grown plants with those from two biowalls, while also comparing communities from roots exposed to clean versus VOC-laden air in a laboratory biofiltration system. The results showed differences in bacterial communities between soil-grown and biowall-grown plants and between bacterial communities from plant roots exposed to clean air and those from VOC-exposed plant roots. Both biowall-grown and VOC-exposed roots harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize that these bacteria are important VOC degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species, suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters. PMID:24878602

  4. Indoor-biofilter growth and exposure to airborne chemicals drive similar changes in plant root bacterial communities.

    PubMed

    Russell, Jacob A; Hu, Yi; Chau, Linh; Pauliushchyk, Margarita; Anastopoulos, Ioannis; Anandan, Shivanthi; Waring, Michael S

    2014-08-01

    Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean indoor air of harmful volatile organic compounds (VOCs), which are typically found at concentrations higher indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or biowalls, converting VOCs into biomass, energy, and carbon dioxide, but little is known about the root microbial communities of such artificially grown plants, how or whether they differ from those of plants grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigated how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through 16S rRNA amplicon sequencing, we compared root bacterial communities from soil-grown plants with those from two biowalls, while also comparing communities from roots exposed to clean versus VOC-laden air in a laboratory biofiltration system. The results showed differences in bacterial communities between soil-grown and biowall-grown plants and between bacterial communities from plant roots exposed to clean air and those from VOC-exposed plant roots. Both biowall-grown and VOC-exposed roots harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize that these bacteria are important VOC degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species, suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters.

  5. Indoor-Biofilter Growth and Exposure to Airborne Chemicals Drive Similar Changes in Plant Root Bacterial Communities

    PubMed Central

    Hu, Yi; Chau, Linh; Pauliushchyk, Margarita; Anastopoulos, Ioannis; Anandan, Shivanthi; Waring, Michael S.

    2014-01-01

    Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean indoor air of harmful volatile organic compounds (VOCs), which are typically found at concentrations higher indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or biowalls, converting VOCs into biomass, energy, and carbon dioxide, but little is known about the root microbial communities of such artificially grown plants, how or whether they differ from those of plants grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigated how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through 16S rRNA amplicon sequencing, we compared root bacterial communities from soil-grown plants with those from two biowalls, while also comparing communities from roots exposed to clean versus VOC-laden air in a laboratory biofiltration system. The results showed differences in bacterial communities between soil-grown and biowall-grown plants and between bacterial communities from plant roots exposed to clean air and those from VOC-exposed plant roots. Both biowall-grown and VOC-exposed roots harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize that these bacteria are important VOC degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species, suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters. PMID:24878602

  6. Mold and Endotoxin Levels in the Aftermath of Hurricane Katrina: A Pilot Project of Homes in New Orleans Undergoing Renovation

    PubMed Central

    Chew, Ginger L.; Wilson, Jonathan; Rabito, Felicia A.; Grimsley, Faye; Iqbal, Shahed; Reponen, Tiina; Muilenberg, Michael L.; Thorne, Peter S.; Dearborn, Dorr G.; Morley, Rebecca L.

    2006-01-01

    Background After Hurricane Katrina, many New Orleans homes remained flooded for weeks, promoting heavy microbial growth. Objectives A small demonstration project was conducted November 2005–January 2006 aiming to recommend safe remediation techniques and safe levels of worker protection, and to characterize airborne mold and endotoxin throughout cleanup. Methods Three houses with floodwater lines between 0.3 and 2 m underwent intervention, including disposal of damaged furnishings and drywall, cleaning surfaces, drying remaining structure, and treatment with a biostatic agent. We measured indoor and outdoor bioaerosols before, during, and after intervention. Samples were analyzed for fungi [culture, spore analysis, polymerase chain reaction (PCR)] and endotoxin. In one house, real-time particle counts were also assessed, and respirator-efficiency testing was performed to establish workplace protection factors (WPF). Results At baseline, culturable mold ranged from 22,000 to 515,000 colony-forming units/m3, spore counts ranged from 82,000 to 630,000 spores/m3, and endotoxin ranged from 17 to 139 endotoxin units/m3. Culture, spore analysis, and PCR indicated that Penicillium, Aspergillus, and Paecilomyces predominated. After intervention, levels of mold and endotoxin were generally lower (sometimes, orders of magnitude). The average WPF against fungal spores for elastomeric respirators was higher than for the N-95 respirators. Conclusions During baseline and intervention, mold and endotoxin levels were similar to those found in agricultural environments. We strongly recommend that those entering, cleaning, and repairing flood-damaged homes wear respirators at least as protective as elastomeric respirators. Recommendations based on this demonstration will benefit those involved in the current cleanup activities and will inform efforts to respond to future disasters. PMID:17185280

  7. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  8. Endotoxin Induced Disseminated Intravascular Coagulation in Cattle

    PubMed Central

    Thomson, G. W.; McSherry, B. J.; Valli, V. E. O.

    1974-01-01

    Endotoxin administered intravenously to a group of four calves resulted in disseminated intravascular coagulation. A sublethal dose of piromen, a commercially available Pseudomonas spp endotoxin, was used. Serial measurements of total plasma fibrinogen, soluble fibrin levels, ethanol gelation tests, protamine sulfate tests, fibrinogen-fibrin-related antigen (FR-antigen) and prothrombin and thrombin times were done. Initial depression of plasma fibrinogen with a nadir of about 40% of pre-endotoxin levels at eight to 11 hours post-endotoxin (+8 to +11 hours) followed by an overcompensation to 180% at +60 to +108 hours was shown. Soluble fibrin was demonstrated in plasma from +2 to +22 hours with a peak of 100-114 mg/100 ml at +4 to +9 hours. Positive plasma ethanol gelation and protamine sulfate tests, as well as the presence of serum FR-antigen, occurred consistently following endotoxin administration. Significant increases in prothrombin times (PT) from +4 to +40 hours and in thrombin times (TT) from +4 to +16 hours were demonstrated. The peak increase of PT at +8 to +10 hours was 180%. The peak increase of TT at +6 to +9 hours was 260-290%. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4. PMID:4279765

  9. Studies with Radioactive Endotoxin II. Clearance of 3H-Labelled Endotoxin from the Blood of Calves

    PubMed Central

    Maxie, M. G.; Valli, V. E. O.; Lumsden, J. H.

    1974-01-01

    The clearance of 3H-labelled Pseudomonas endotoxin from the blood was studied in a nontolerant and in an endotoxin tolerant state. Calves were rendered tolerant to the toxic effects of the endotoxin by four daily intravenous injections of endotoxin at the dose rate of 5 µg/kg body weight. Clearance of 3H-endotoxin from the blood of nontolerant calves occurred more slowly than did clearance of 51Cr-endotoxin and was not significantly (P<0.05) affected by the development of tolerance. The lungs and liver were the major organs involved in the clearance of 3H-endotoxin from the blood of calves. Leukocytes and erythrocytes, but not platelets, were shown to participate in endotoxin clearance in calves. 3H2O, the control substance used in calves, was not concentrated within any particular organ but rapidly equilibrated with total body water and was slowly excreted. PMID:4279755

  10. Exposure to airborne PM2.5 suppresses microRNA expression and deregulates target oncogenes that cause neoplastic transformation in NIH3T3 cells

    PubMed Central

    Cheng, Xinxin; Shao, Mingming; Wu, Chen; Wang, Suhan; Li, Hongmin; Wei, Lixuan; Gao, Yanning; Tan, Wen; Cheng, Shujun; Wu, Tangchun; Yu, Dianke; Lin, Dongxin

    2015-01-01

    Long-term exposure to airborne PM2.5 is associated with increased lung cancer risk but the underlying mechanism remains unclear. We characterized global microRNA and mRNA expression in human bronchial epithelial cells exposed to PM2.5 organic extract and integrally analyzed microRNA-mRNA interactions. Foci formation and xenograft tumorigenesis in mice with NIH3T3 cells expressing genes targeted by microRNAs were performed to explore the oncogenic potential of these genes. We also detected plasma levels of candidate microRNAs in subjects exposed to different levels of air PM2.5 and examined the aberrant expression of genes targeted by these microRNAs in human lung cancer. Under our experimental conditions, treatment of cells with PM2.5 extract resulted in downregulation of 138 microRNAs and aberrant expression of 13 mRNAs (11 upregulation and 2 downregulation). In silico and biochemical analyses suggested SLC30A1, SERPINB2 and AKR1C1, among the upregulated genes, as target for miR-182 and miR-185, respectively. Ectopic expression of each of these genes significantly enhanced foci formation in NIH3T3 cells. Following subcutaneous injection of these cells into nude mice, fibrosarcoma were formed from SLC30A1- or SERPINB2-expressing cells. Reduced plasma levels of miR-182 were detected in subjects exposed to high level of PM2.5 than in those exposed to low level of PM2.5 (P = 0.043). Similar results were seen for miR-185 although the difference was not statistically significant (P = 0.328). Increased expressions of SLC30A1, SERPINB2 and AKR1C1 were detected in human lung cancer. These results suggest that modulation of miR-182 and miR-185 and their target genes may contribute to lung carcinogenesis attributable to PM2.5 exposure. PMID:26338969

  11. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

    ATM (Airborne Thematic Mapper) was developed for NSTL (National Space Technology Companies) by Daedalus Company. It offers expanded capabilities for timely, accurate and cost effective identification of areas with prospecting potential. A related system is TIMS, Thermal Infrared Multispectral Scanner. Originating from Landsat 4, it is also used for agricultural studies, etc.

  12. [MicroRNA's role in sepsis and endotoxin tolerance. More players on the stage].

    PubMed

    Gîză, D E; Vasilescu, C

    2010-01-01

    MicroRNAs are non-coding RNA fragments, well characterized and well preserved along the evolution of the species and whose essential role is to regulate gene expression. MicroRNAs perform its action on messenger RNA ("target"). They induce degradation or repression of target translation with a significant decrease in the quantity and the activity of proteins. MicroRNAs are involved in normal cell function. Abnormal levels of microRNA were found in several pathological contiditions such as cancer, autoimmune diseases, viral infections, sepsis. Sepsis appears as a result of an improper inflammatory response after systemic bacterial infection. It remains a disease with a high incidence and mortality despite the evolution of diagnostic and treatment techniques. Sepsis patients have similar features to those found in the endotoxin tolerance phenomenon. Endotoxin tolerance is a state of hyporesponsivness to endotoxin challenge induced by a prior exposure. Due to its important role in repression of the pro-inflammatory cytokines translation, microRNA can be considered a new mechanism of endotoxin tolerance and a new mechanism involved in sepsis pathogenesis. In sepsis patients abnormal levels of the following types of microRNA were found: miR-146, miR-155, miR150, miR-132. Further studies are carried out to demonstrate the potential role of microRNA as biomarkers in sepsis.

  13. Allantoin as a solid phase adsorbent for removing endotoxins.

    PubMed

    Vagenende, Vincent; Ching, Tim-Jang; Chua, Rui-Jing; Gagnon, Pete

    2013-10-01

    In this study we present a simple and robust method for removing endotoxins from protein solutions by using crystals of the small-molecule compound 2,5-dioxo-4-imidazolidinyl urea (allantoin) as a solid phase adsorbent. Allantoin crystalline powder is added to a protein solution at supersaturated concentrations, endotoxins bind and undissolved allantoin crystals with bound endotoxins are removed by filtration or centrifugation. This method removes an average of 99.98% endotoxin for 20 test proteins. The average protein recovery is ∼80%. Endotoxin binding is largely independent of pH, conductivity, reducing agent and various organic solvents. This is consistent with a hydrogen-bond based binding mechanism. Allantoin does not affect protein activity and stability, and the use of allantoin as a solid phase adsorbent provides better endotoxin removal than anion exchange, polymixin affinity and biological affinity methods for endotoxin clearance.

  14. [The role of bacterial endotoxins, receptors and cytokines in the pathogenesis of septic (endotoxin) shock].

    PubMed

    Lazarov, S; Balutsov, M; Ianev, E

    2000-01-01

    Sepsis, resistant to therapy, results in the development of septic (endotoxin) shock. The latter is caused by the endotoxins of different Gram-negative bacteria. Endotoxin (bacterial lipopdisacharide--LPS) interacts with cells through specific membrane or plasma soluble endotoxin receptors (sCD14, mlD14, LBP, CD13/CD14, CD16, CD116/CD18, L-selectin, etc.). Endotoxin interaction with the mCD14 receptor of the monocytes, macrophages and the neutrophils results in the production of a number of proinflammatory cytokines--tumor necrosis factor alpha (TNF alpha), interleukines 1 and 6 (IL-1 and IL-6, etc), antiinflammatory cytokines--interleukines 10 and 12 (IL-10 and IL-12), cell adhesion molecules (P-selectin, E-selectin, ICAM-1, VCAM-1, etc.) and inducible enzymes: inducible NO synthase (iNOS), inducible phospholipase A2 (cPL-A2), inducible cyclooxygenase (COX-2). All pathologic processes in the structure and function of human body during endotoxin shock are a result of the disbalance of a number of mediators with a proinflammatory and antiinflammatory effects.

  15. Removal of endotoxin from dairy wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of various treatments on removing endotoxin (ET) from wastewater was tested by using the treated water to induce a systemic reaction via intratracheal inoculation (20 ml/goat, 6 goats/group). Treatments (T1-T7) of wastewater were as follows: 1) autoclaved 15 min, centrifuged and contain...

  16. Bronchial Venular Leakage During Endotoxin Shock

    PubMed Central

    Pietra, G. G.; Szidon, J. P.; Carpenter, H. A.; Fishman, A. P.

    1974-01-01

    The pulmonary effects of endotoxin shock were investigated in dogs by a combination of anatomic and physiologic technics. Shock was produced in 14 dogs by injecting Escherichia coli lipopolysaccharide intravenously. Three dogs in hypovolemic shock and 6 untreated dogs served as controls. Colloidal carbon was injected intravenously to detect sites of pathologic increase in vascular permeability. During the first hour of endotoxin shock, bronchial venules allowed carbon and blood elements to traverse their walls, whereas no leakage of these large particles or ultrastructural changes could be detected in the alveolar walls. Only after the first hour was bronchial venular leakage accompanied by focal degenerative changes in the alveolar endothelium, focal interstitial edema in the alveolar septum and sequestration of damaged leukocytes in the alveolar capillaries. In contrast to these observations in endotoxin shock, control dogs in hypovolemic shock did not show bronchial venous leakage. Our findings suggest that the leakage of bronchial venules may be involved in the pathogenesis of pulmonary interstitial edema caused by endotoxin shock. ImagesFig 2Fig 3Fig 4Fig 1 PMID:4611225

  17. Possible mechanism for preterm labor associated with bacterial infection. I. Stimulation of phosphoinositide metabolism by endotoxin in endometrial fibroblasts

    SciTech Connect

    Khan, A.A.; Imai, A.; Tamaya, T. )

    1990-07-01

    Growing evidence suggests an association between intra-amniotic infection and premature initiation of parturition. We recently demonstrated that some factor(s) including endotoxin produced by the organism stimulates endogenous phospholipase A2 resulting in liberation of arachidonic acid and prostaglandin formation. The studies presented in this report were designated to evaluate the mechanism for endotoxin to stimulate phospholipase A2 using human endometrial fibroblasts. Exposure of the fibroblasts to endotoxin from Escherichia coli in the presence of ({sup 32}P) phosphate increased {sup 32}P-labeling of phosphatidic acid (PA) and phosphatidyl-inositol (PI) in a dose-dependent and a time-dependent manners. The PA labeling occurred without a measurable lag time. These findings demonstrate that the endotoxin stimulates phosphoinositide metabolism in human endometrial fibroblasts by a receptor-mediated mechanism. Membrane phosphoinositide turnover stimulated by endotoxin results in cytosolic Ca{sup 2+} increment, liberation of arachidonic acid, which may be involved in the initiation of parturition.

  18. Mediated effect of endotoxin and lead upon hepatic metabolism

    SciTech Connect

    Kuttner, R.E.; Ebata, T.; Schumer, W.

    1984-10-01

    A test was made of the possibility that gram-negative bacterial cell wall lipopolysaccharides acted directly on key glucoregulatory enzymes in rat liver cytosol to cause the characteristic hypoglycemia of severe endotoxemia. Fasted male rats were sensitized to endotoxin by the simultaneous intravenous injection of lead acetate. The minimum systemic dosage of endotoxin necessary to perturb the normal pattern of hepatic glycolytic intermediates was determined by serial testing with diminishing dosages of endotoxin. The hepatocyte concentration of endotoxin was then calculated from this minimum dosage by use of literature data on the fraction of endotoxin delivered to liver cells after a systemic intravenous injection of radiochromium labeled lipopolysaccharides. Accepting a molecular weight of 118,000 daltons for the smallest endotoxin monomer capable of evoking a physiologic response, the molar amount of endotoxin present in 1 gram of hepatocytes was readily calculated. The concentration of glucoregulatory enzymes in parenchymal cells was then estimated from other literature sources. It was found that the amount of endotoxin in the hepatocytes was insufficient to combine directly with even 1 per cent of the quantity of a single key glucoregulatory enzyme in liver parenchyma. Since a one to one stoichiometric reaction between endotoxin and enzyme could not occur in the liver cytosol, a direct interaction mechanism between agonist and biocatalyst can be ruled out. It is concluded that bacterial endotoxin must act on hepatic glucoregulation by an indirect mechanism presumably based upon the release and operation of mediators.

  19. Detecting endotoxin with a flow cytometry-based magnetic aptasensor.

    PubMed

    Zuo, Ming-Yan; Chen, Li-Juan; Jiang, Hao; Tan, Lin; Luo, Zhao-Feng; Wang, Yan-Mei

    2014-12-01

    Endotoxin, which is also known as lipopolysaccharide (LPS), is a marker for intruding gram-negative pathogens. It is essential to detect endotoxin quickly and sensitively in a complex milieu. A new flow cytometry (FCM)-based magnetic aptasensor assay that employs two endotoxin-binding aptamers and magnetic beads has been developed to detect endotoxin. The endotoxin-conjugated sandwich complex on magnetic beads was observed by scanning confocal laser microscopy. The resulting magnetic aptasensor rapidly detected (<1 min) endotoxin within a broad dynamic detection range of 10(-8) to 10(0)mg/ml in the presence of bovine serum albumin (BSA), RNA, sucrose, and glucose, which are most likely to coexist with endotoxin in the majority of biological liquids. Only 2 μl of magnetic aptasensor was required to quantify the endotoxin solution. Furthermore, the magnetic aptasensor could be regenerated seven times and still presented an outstanding response to the endotoxin solution. Therefore, the magnetic aptasensor exhibited high sensitivity, selectivity, and reproducibility, thereby serving as a powerful tool for the quality control and high-throughput detection of endotoxin in the food and pharmaceutical industries.

  20. Mutagenicity of airborne particles.

    PubMed

    Chrisp, C E; Fisher, G L

    1980-09-01

    The physical and chemical properties of airborne particles are important for the interpretation of their potential biologic significance as genotoxic hazards. For polydisperse particle size distributions, the smallest, most respirable particles are generally the most mutagenic. Particulate collection for testing purposes should be designed to reduce artifact formation and allow condensation of mutagenic compounds. Other critical factors such as UV irradiation, wind direction, chemical reactivity, humidity, sample storage, and temperature of combustion are important. Application of chemical extraction methods and subsequent class fractionation techniques influence the observed mutagenic activity. Particles from urban air, coal fly ash, automobile and diesel exhaust, agricultural burning and welding fumes contain primarily direct-acting mutagens. Cigarette smoke condensate, smoke from charred meat and protein pyrolysates, kerosene soot and cigarette smoke condensates contain primarily mutagens which require metabolic activation. Fractionation coupled with mutagenicity testing indicates that the most potent mutagens are found in the acidic fractions of urban air, coal fly ash, and automobile diesel exhaust, whereas mutagens in rice straw smoke and cigarette smoke condensate are found primarily in the basic fractions. The interaction of the many chemical compounds in complex mixtures from airborne particles is likely to be important in determining mutagenic or comutagenic potentials. Because the mode of exposure is generally frequent and prolonged, the presence of tumor-promoting agents in complex mixtures may be a major factor in evaluation of the carcinogenic potential of airborne particles.

  1. Mammalian airborne allergens.

    PubMed

    Aalberse, Rob C

    2014-01-01

    Historically, horse dandruff was a favorite allergen source material. Today, however, allergic symptoms due to airborne mammalian allergens are mostly a result of indoor exposure, be it at home, at work or even at school. The relevance of mammalian allergens in relation to the allergenic activity of house dust extract is briefly discussed in the historical context of two other proposed sources of house dust allergenic activity: mites and Maillard-type lysine-sugar conjugates. Mammalian proteins involved in allergic reactions to airborne dust are largely found in only 2 protein families: lipocalins and secretoglobins (Fel d 1-like proteins), with a relatively minor contribution of serum albumins, cystatins and latherins. Both the lipocalin and the secretoglobin family are very complex. In some instances this results in a blurred separation between important and less important allergenic family members. The past 50 years have provided us with much detailed information on the genomic organization and protein structure of many of these allergens. However, the complex family relations, combined with the wide range of post-translational enzymatic and non-enzymatic modifications, make a proper qualitative and quantitative description of the important mammalian indoor airborne allergens still a significant proteomic challenge. PMID:24925404

  2. Applicability of bacterial endotoxins test to various blood products by the use of endotoxin-specific lysates.

    PubMed

    Ochiai, Masaki; Yamamoto, Akihiko; Naito, Seishiro; Maeyama, Jun-Ichi; Masumi, Atsuko; Hamaguchi, Isao; Horiuchi, Yoshinobu; Yamaguchi, Kazunari

    2010-11-01

    Endotoxin contamination is a serious threat to the safety of parenteral drugs, and the rabbit pyrogen test has played a crucial role in controlling this contamination. Although the highly sensitive endotoxin test has replaced the pyrogen test for various pharmaceuticals, the pyrogen test is still implemented as the control test for most blood products in Japan. We examined the applicability of the endotoxin test to blood products for reliable detection and quantification of endotoxin. Nineteen types of blood products were tested for interfering factors based on spike/recovery of endotoxin by using 2 types of endotoxin-specific lysate reagents for photometric techniques. Interfering effects on the endotoxin test by the products could be eliminated by diluting from 1/2 to 1/16, with the exception of antithrombin III. However, conventional lysate reagents that also react with non-pyrogenic substances, such as (1-3)-β-D-glucan, produced results that were not relevant to endotoxin content or pyrogenicity. Our results showed that the endotoxin test would be applicable to most blood products if used with appropriate endotoxin-specific lysate reagents.

  3. The exposure assessment of airborne particulates matter (PM10 & PM2.5) towards building occupants: A case study at KL Sentral, Kuala Lumpur, Malaysia

    NASA Astrophysics Data System (ADS)

    Mohddin, S. A.; Aminuddin, N. M.

    2014-02-01

    Airborne particulates have been recognized as a crucial pollutant of indoor air. These pollutants can contribute towards poor indoor air quality (IAQ), which may affect human health in immediate or long term. This study aims to determine the level of IAQ and the effects of particulate towards occupants of office buildings (the office buildings selected for the case study are SSM, KTMB and MRCB at KL Sentral). The objectives of study are (i) to measure the level of airborne particulates that contribute to the IAQ during working hours, (ii) to compare the level of airborne particulates with the existing guidelines and standards of IAQ in Malaysia and other Asian countries and (iii) to assess the symptoms associated with airborne particulates among the building occupants, which were achieved through primary data collection (case study or site survey, structured interview and questionnaire survey) and supported by literature reviews. The results showed that the mass concentration level of airborne particulates within the areas has exceeded the allowable limit of 0.15mg/m3 by IAQ Code of Practice, 2005 of the Department of Safety and Health (DOSH), Malaysia and 0.05mg/m3 by the Department of Environmental (DOE) (outdoor) of 8 hours continuous sampling. Based on the findings, the highest mass concentration values measured is 2.581 mg/m3 at lobby of SSM building which is the highest recorded 17 times higher from the maximum limit recommended by DOSH than the others. This is due to the nearby construction works and the high numbers of particulates are generated from various types of vehicles for transportation surrounding KL Sentral. Therefore, the development of Malaysian Ambient Air Quality Guidelines on PM2.5 as one of the crucial parameters is highly recommended.

  4. Green job bio-aerosol exposure during anaerobic digestion for biomass energetic valorisation.

    PubMed

    Traversi, Deborah; Gorrasi, Ilaria; Bonetta, Sara; Leinardi, Riccardo; Pietrangeli, Biancamaria; Carraro, Elisabetta; Gilli, Giorgio

    2015-04-01

    The continued expansion of the green economy increases the risk profile for green occupational jobs. One of the broadest green sectors in terms of growth is the anaerobic digestion of biomasses. In recent years, this development has also interested Italian regions. The management of biomass includes biological risk and the risk of particulate and endotoxin exposure. In the present study, we evaluated airborne exposure for anaerobic digestion workers at two real-scale plants. Digested biomass has different origins, ranging from cattle sludge and manure to poultry manure to agricultural harvesting or processing residues, particularly from maize and fruits. Two sampling points were chosen: at the first, the input biomasses were stored, and the hopper was loaded; at the second, the digested sludge exited the digester. The microbiological parameters, assessed using an active sampler and cultural method, were the total bacteria counts (at 22, 37, and 55°C), yeasts, fungi, Pseudomonaceae, Clostridia spp., Enterobacteriaceae and Actinomycetes. Moreover, at the same sampling points, we evaluated six PM10 fraction levels (10.0-7.2, 7.2-3.0, 3.0-1.5, 1.5-0.95, 0.95-0.49, and <0.49µm) and the endotoxin content of each fraction. In this investigation, the microbe contamination of the air varied from low to high levels, while the PM10 and endotoxin levels were limited, reaching rural environmental levels (61.40µg/m(3) and 18.88EU/m(3), respectively). However, contamination and occupational risk must be evaluated individually for each plant because numerous variables influence the risk magnitude, particularly digested sludge treatments, such as input biomass nature, storage, movement conditions, building configuration and technological processes.

  5. Effect of hypertriglyceridemia on endotoxin responsiveness in humans.

    PubMed

    van der Poll, T; Braxton, C C; Coyle, S M; Boermeester, M A; Wang, J C; Jansen, P M; Montegut, W J; Calvano, S E; Hack, C E; Lowry, S F

    1995-09-01

    Triglyceride-rich lipoproteins can inhibit endotoxin activity in vitro and in rodents. We sought to determine whether Intralipid, a triglyceride-rich fat emulsion which in contact with plasma functions similarly to endogenous lipoproteins, can alter the human response to endotoxin. Intralipid inhibited endotoxin-induced cytokine production in human whole blood in vitro in a dose-dependent manner, with maximal inhibition (up to 70%) being achieved at a concentration of 10 g/liter. In healthy men, a bolus intravenous injection of endotoxin (lot EC-5; 20 U/kg of body weight) was given midway through a 4-h infusion (125 ml/h) of either 5% glucose (n = 5) or 20% Intralipid (n = 5). The infusion of Intralipid led to an increase in triglyceride levels in serum from 95 +/- 16 to 818 +/- 135 mg/dl prior to endotoxin administration, i.e., levels that importantly reduced cytokine production in endotoxin-stimulated whole blood. However, in vivo hypertriglyceridemia did not influence inflammatory responses to endotoxin (fever, release of tumor necrosis factor and soluble tumor necrosis factor receptors, and leukocytosis) or even potentiated endotoxin responses (release of interleukins 6 and 8 and neutrophil degranulation). Hypertriglyceridemia does not inhibit the in vivo responses to endotoxin in humans.

  6. Fluorescent nanodiamonds as highly stable biomarker for endotoxin verification

    NASA Astrophysics Data System (ADS)

    Bergmann, Thorsten; Burg, Jan Michael; Lilholt, Maria; Maeder, Ulf; Beer, Sebastian; Salzig, Denise; Ebrahimi, Mehrdad; Czermak, Peter; Fiebich, Martin

    2012-03-01

    Fluorescent nanodiamonds (ND) provide advantageous properties as a fluorescent biomarker for in vitro and in vivo studies. The maximum fluorescence occurs around 700 nm, they do not show photobleaching or blinking and seem to be nontoxic. After a pretreatment with strong acid fluorescent ND can be functionalized and coupled to endotoxin. Endotoxin is a decay product of bacteria and causes strong immune reactions. Therefore endotoxin has to be removed for most applications. An effective removal procedure is membrane filtration. The endotoxin, coupled to fluorescent ND can be visualized by using confocal microscopy which allows the investigation of the separation mechanisms of the filtration process within the membranes.

  7. Pulmonary inflammation induced by repeated inhalations of beta(1,3)-D-glucan and endotoxin.

    PubMed Central

    Fogelmark, B.; Sjöstrand, M.; Rylander, R.

    1994-01-01

    In an animal model of hypersensitivity pneumonitis (HP) guinea-pigs were exposed for 5 weeks to an aerosol of bacterial endotoxin, beta(1,3)-D-glucan (curdlan) or a combination. Exposure to endotoxin or curdlan showed only small changes in inflammatory cells in airways or the lung wall, histologically or in terms of enzyme secretion from alveolar macrophages. When the two agents were given together, a histology resembling HP was seen with alveolar infiltrates and early granulomas. Inflammatory cells in airways were increased and enzyme production of macrophages was changed, suggesting an effect of curdlan on the inflammatory regulating capacity of airway macrophages. The results suggest that interference with macrophage function and inflammation are important components in the development of HP. PMID:8199009

  8. EFFECTS OF LIME (CAO) ON THE ENDOTOXIN LEVELS OF BIOSOLIDS

    EPA Science Inventory

    Lime addition is a common practice for treating biosolids in order to meet EPA 503 requirements for land application. Since this treatment kills the majority of microorganisms, will it increase the level of endotoxins present in biosolids? And, if endotoxin levels are increased, ...

  9. General effect of endotoxin on glucocorticoid receptors in mammalian tissues

    SciTech Connect

    Stith, R.D.; McCallum, R.E.

    1986-01-01

    Considering the ubiquitous nature of glucocorticoid actions and the fact that endotoxin inhibits glucocorticoid action in the liver, we proposed to examine whether endotoxin affected extrahepatic actions of glucocorticoids. Fasted C57BL/6J mice were injected intraperitoneally with endotoxin (LD50) at 0800 and were killed 6 h later. Control mice were injected with an equal volume of saline. /sup 3/H-dexamethasone binding, measured by a new cytosol exchange assay utilizing molybdate plus dithiothreitol, in liver, kidney, skeletal muscle, spleen, lung, and heart tissue was significantly lower in treated than in control mice. The equilibrium dissociation constants were not significantly different, but the number of available binding sites in each tissue was reduced by endotoxin treatment. Phosphoenolpyruvate carboxykinase activity was significantly reduced in liver but not in kidney. Endotoxin treatment lowered glycogen content in liver but not in skeletal muscle. The reduction observed in the a form of liver glycogen synthase due to endotoxin was not seen in skeletal muscle glycogen synthase a. These data support the proposal that endotoxin or a mediator of its action inhibits systemic glucocorticoid action. The results also emphasize the central role of the liver in the metabolic disturbances of the endotoxin-treated mouse.

  10. Modeling for Airborne Contamination

    SciTech Connect

    F.R. Faillace; Y. Yuan

    2000-08-31

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of sufficient thickness to simulate the drift

  11. A COMMON HAPLOTYPE OF THE TUMOUR NECROSIS FACTOR RECEPTOR 2 GENE MODULATES ENDOTOXIN TOLERANCE

    PubMed Central

    Fairfax, Benjamin P.; Davenport, Emma E.; Makino, Seiko; Hill, Adrian V.S.; Vannberg, Fredrik O.; Knight, Julian C.

    2011-01-01

    Endotoxin tolerance is characterized by the suppression of further TNF release upon recurrent exposure to LPS. This phenomenon is proposed to act as a homeostatic mechanism preventing uncontrolled cytokine release such as that observed in bacterial sepsis. The regulatory mechanisms and inter-individual variation of endotoxin tolerance induction in man remain poorly characterized. Here we describe a genetic association study of variation in endotoxin tolerance amongst healthy individuals. We identify a common promoter haplotype in TNFRSF1B (encoding TNFR2) to be strongly associated with reduced tolerance to LPS (P = 5.82×10−6). This identified haplotype is associated with increased expression of TNFR2 (P = 4.9 ×10−5) and we find basal expression of TNFR2, irrespective of genotype and unlike TNFR1, is associated with secondary TNF release (P <0.0001). Functional studies demonstrate a positive feedback loop via TNFR2 of LPS induced TNF release, confirming this previously unrecognized role for TNFR2 in the modulation of LPS response. PMID:21282507

  12. Impaired host resistance to endotoxin and malaria in polychlorinated biphenyl- and hexachlorobenzene-treated mice.

    PubMed Central

    Loose, L D; Silkworth, J B; Pittman, K A; Benitz, K F; Mueller, W

    1978-01-01

    The in vivo effect of polychlorinated biphenyl (PCB) and hexachlorobenzene (HCB) on murine endotoxin sensitivity and resistance to malaria (Plasmodium berghei NYU-2) infection was studied. The dietary administration of 167 ppm (167 microgram/g) of PCB 1242 or HCB for 3 weeks resulted in an enhanced sensitivity to gram-negative endotoxin (Salmonella typhosa), which was further increased in animals maintained on the diets for 6 weeks. By 6 weeks, a 5.2- or 32-fold increase in endotoxin sensitivity was seen in mice fed PCB or HCB, respectively. A 20% decrease in mean survival time of mice fed PCB 1242 for 3 or 6 weeks and inoculated with malaria was demonstrated. Infected mice that received HCB for 3 or 6 weeks manifested a reduction in mean survival time of 24 or 31%, respectively. Histopathological examination revealed a normal thymus, spleen, mesenteric lymph nodes, and lungs. Centrilobular and pericentral hepatocyte hypertrophy, common to organochlorine exposure, was observed. Electron capture gas chromatographic analysis for PCB 1242 or HCB in the tissues examined histologically revealed a significant deposit of the xenobiotics. HCB concentration was approximately 16 to 25 times greater than that of PCB. The data indicate that environmental chemicals impair host resistance and that the alteration may be related to the presence of the chemicals in the lymphoreticular organs. PMID:97225

  13. Levels of bacteria, fungi, and endotoxin in bulk and aerosolized corn silage.

    PubMed Central

    Dutkiewicz, J; Olenchock, S A; Sorenson, W G; Gerencser, V F; May, J J; Pratt, D S; Robinson, V A

    1989-01-01

    Three samples of silage taken from the surface of a silo and from depths of 20 and 45 cm in the silo were studied for identification of the potential agents causing symptoms of organic dust toxic syndrome. The samples were examined by dilution plating before and after aerosolization in an acoustical dust generator. Aerosol samples were collected by liquid impinger and filter cassettes. The samples were examined for total aerobic bacteria, anaerobic bacteria, gram-negative bacteria, lactobacilli, listeriae, thermophilic actinomycetes, fungi, and endotoxin. Very high levels of total aerobic bacteria and fungi were found in the surface sample (up to 10(9) CFU/g in the bulk sample and up to 10(9) CFU/m3 after aerosolization), whereas the corresponding values from the deepest site were 100 to 50,000 times lower. Aspergillus fumigatus predominated among the fungi, whereas Bacillus and gram-negative organisms (Pseudomonas, Alcaligenes, Citrobacter, and Klebsiella species) prevailed among bacteria. Thermophilic actinomycetes occurred in numbers up to 10(7) CFU/g in the bulk samples, whereas anaerobic bacteria, lactobacilli, and listeriae were only few or absent. The concentration of endotoxin was high in the surface sample (up to 211.4 Endotoxin Units/mg) and about 200-fold lower in the sample from the deepest site. The results show that contact with dust from the surface of silage carries the risk of exposure to high concentrations of microorganisms, of which A. fumigatus and endotoxin-producing bacteria are the most probable disease agents. PMID:2757375

  14. Effect of vasopressors on organ blood flow during endotoxin shock in pigs

    SciTech Connect

    Breslow, M.J.; Miller, C.F.; Parker, S.D.; Walman, A.T.; Traystman, R.J.

    1987-02-01

    A volume-resuscitated porcine endotoxin shock model was used to evaluate the effect on organ blood flow of increasing systemic arterial blood pressure with vasopressors. Administration of 0.05-0.2 mg/kg of Escherichia coli endotoxin (E) reduced mean arterial blood pressure (MAP) to 50 mmHg, decreased systemic vascular resistance to 50% of control, and did not change cardiac output or heart rate. Blood flow measured with radiolabeled microspheres to brain, kidney, spleen, and skeletal muscle was reduced during endotoxin shock, but blood flow to left ventricle, small and large intestine, and stomach remained at pre-endotoxin levels throughout the study period. Four groups of animals were used to evaluate the effect of vasopressor therapy. Vasopressors were administered starting 60 min after E exposure, and the dose of each was titrated to increase MAP to 75 mmHg. Despite the increase in MAP, brain blood flow did not increase in any group. Norepinephrine alone increased blood flow to the left ventricle. The dose of norepinephrine required to increase MAP by 20-25 mmHg during E shock was 30 times the does required for a similar increase in MAP in animals not receiving E. The authors conclude 1) that hypotension in the fluid resuscitated porcine E shock model is primarily the result of peripheral vasodilatation, 2) that the vascular response to vasoconstrictors in this model is markedly attenuated following E administration, 3) that blood pressure elevation with norepinephrine, dopamine, and phenylephrine neither decreases blood flow to any organs nor increases blood flow to organs with reduced flow, and 4) that norepinephrine, dopamine, and phenylephrine affect regional blood flow similarly in this model.

  15. Collagenase Production by Endotoxin-Activated Macrophages

    PubMed Central

    Wahl, Larry M.; Wahl, Sharon M.; Mergenhagen, Stephan E.; Martin, George R.

    1974-01-01

    Peritoneal exudate macrophages, when exposed to bacterial lipopolysaccharide in culture, were found to produce collagenase (EC 3.4.24.3). This enzyme was not detected in extracts of the macrophages or in media from nonstimulated macrophage cultures. Lipidcontaining fractions of the lipopolysaccharide, including a glycolipid from the rough mutant of Salmonella minnesota (R595) and lipid A, were potent stimulators of collagenase production. The lipid-free polysaccharide fraction had no effect. Cycloheximide prevented the production of collagenase by endotoxin-treated macrophages, suggesting that it was newly synthesized. Images PMID:4372628

  16. Endotoxin treatment protects rats against ozone-induced lung edema: with evidence for the role of manganese superoxide dismutase

    SciTech Connect

    Rahman, I.; Massaro, D. )

    1992-03-01

    Ozone is a strong oxidizing agent that can cause lung damage and edema. There is evidence that it does so by causing peroxidation of membrane lipids. However, the elevation in lung activity of copper, zinc superoxide dismutase (Cu, ZnSOD), and manganese superoxide dismutase (MnSOD) during exposure to ozone suggests that increased production of superoxide could contribute to lung edema caused by ozone. This latter observation, and preliminary evidence that treatment of rats with endotoxin elevates lung activity of MnSOD without elevation of the activity of Cu, ZnSOD, catalase (CAT), or glutathione peroxidase (GP), led to the present study. We treated rats with endotoxin, exposed them to different concentrations of ozone, measured lung wet weight to dry weight ratio, thiobarbituric acid-reactive material (TBAR), and assayed lung tissue for Cu, ZnSOD, MnSOD, CAT, and GP activity. Our major findings are, (1) a strongly edemogenic concentration of ozone-lowered MnSOD activity; (2) endotoxin treatment of air-breathing rats did not decrease lipid peroxidation as indicated by the lung concentration of TBAR; (3) induction of increased MnSOD activity in lung by treatment with endotoxin was associated with virtually complete protection against an otherwise edemogenic concentration of ozone, with less lipid peroxidation, and with less loss of weight; and (4) this protection occurred without elevated Cu, ZnSOD, CAT, or GP activity.

  17. Indoor airborne fungi and wheeze in the first year of life among a cohort of infants at risk for asthma.

    PubMed

    Rosenbaum, Paula F; Crawford, Judith A; Anagnost, Susan E; Wang, C J K; Hunt, Andrew; Anbar, Ran D; Hargrave, Teresa M; Hall, E Geralyn; Liu, Chien-Chih; Abraham, Jerrold L

    2010-09-01

    In studies worldwide, respiratory outcomes such as cough, wheeze and asthma have been consistently linked to mold exposure. Young children spend most of their time indoors and may be particularly vulnerable. We evaluated the associations between exposure to airborne fungal levels and episodes of wheezing in a cohort of 103 infants at risk for asthma (due to maternal history of asthma), living primarily in low-income urban settings. Using a new protocol that facilitates identification of rare and slow-growing fungi, we measured the type and concentration of cultured fungi in home air samples taken early in the infant's first year of life. We also inspected the homes for visible mold, water damage and other housing and environmental conditions. All homes had measurable indoor airborne fungi and 73%, had some sign of mold, water damage, dampness or a musty odor. One or more episodes of wheeze during the first year of life were observed in 38% of infants. Multiple logistic regression showed high indoor levels of Penicillium were a significant risk factor for wheeze (OR 6.18; 95% CI: 1.34-28.46) in the first year of life after controlling for season of sampling, smoking, endotoxin levels, day care attendance and confounders. Acrodontium, a rarely reported fungal genus, was detected in 18% of study homes, and was associated with wheeze in unadjusted models (OR 2.75; 95% CI 0.99-7.61), but not after adjustment for confounders. Total fungal levels, visually observed mold, dampness, water damage or musty odors were not significantly associated with wheeze.

  18. Endotoxin Elimination in Patients with Septic Shock: An Observation Study.

    PubMed

    Adamik, Barbara; Zielinski, Stanislaw; Smiechowicz, Jakub; Kübler, Andrzej

    2015-12-01

    To evaluate the effectiveness of endotoxin elimination with an adsorption column in patients with septic shock and endotoxemia. The elimination therapy was guided by a new bedside method of measuring endotoxin activity (EA). Intensive care unit (ICU) patients with septic shock and suspected Gram-negative infection were consecutively added to the study group within the first 24 h. Endotoxin elimination was performed using hemoperfusion with the Alteco LPS Adsorber. The primary endpoint was improvement in organ function within the first 24 h of treatment. A secondary objective was to assess the usefulness of a new method of measuring EA to help guide endotoxin elimination therapy. Out of 64 patients 18 had a high baseline EA [0.70 EA units (0.66-0.77)]. Those patients had endotoxin elimination treatment in addition to conventional medical therapy. At 24 h after endotoxin elimination, the EA had decreased to 0.56 EA units (0.43-0.77), (p = 0.005); MAP increased from 69 (62-80) to 80 mm Hg (68-88), (p = 0.002), and noradrenaline use decreased from 0.28 (0.15-0.80) to 0.1 μg/kg/min (0.00-0.70) at the same time (p = 0.04). The SOFA score had decreased from 11 (9-15) to 9 (7-14) points 24 h after endotoxin elimination (p = 0.01) with a median delta SOFA -2 points. Endotoxin elimination did not have a significant effect on the ICU length of stay or ICU mortality. Effective endotoxin elimination resulted in a significant improvement in hemodynamic parameters and of organ function. The application of the EA assay was useful for the bedside monitoring of endotoxemia in critically ill ICU patients.

  19. Adherent endotoxin on dental implant surfaces: a reappraisal.

    PubMed

    Morra, Marco; Cassinelli, Clara; Bollati, Daniele; Cascardo, Giovanna; Bellanda, Marco

    2015-02-01

    Osteoimmunology is the crosstalk between cells from the immune and skeletal systems, suggesting a role of pro-inflammatory cytokines in the stimulation of osteoclast activity. Endotoxin or bacterial challenges to inflammatory cells are directly relevant to dental implant pathologies involving bone resorption, such as osseointegration failure and peri-implantitis. While the endotoxin amount on implant devices is regulated by standards, it is unknown whether commercially available dental implants elicit different levels of adherent-endotoxin stimulated cytokines. The objective of this work is to develop a model system and evaluate endotoxin-induced expression of pro-inflammatory cytokine genes relevant to osteoclast activation on commercially available dental implants. Murine J774-A1 macrophages were cultured on Ti disks with different level of lipopolysaccharide (LPS) contamination to define the time-course of the inflammatory response to endotoxin, as evaluated by reverse transcription polymerase chain reaction analysis. The developed protocol was then used to measure adherent endotoxin on commercially available packaged and sterile dental implants in the "as-implanted" condition. Results show that tested dental implants induce variable expression of endotoxin-stimulated genes, sometimes above the level expected to promote bone resorption in vivo. Results are unaffected by the specific surface treatment; rather, they likely reflect care in cleaning and packaging protocols. In conclusion, expression of genes that enhance osteoclast activity through endotoxin stimulation of inflammatory cells is widely different on commercially available dental implants. A reappraisal of the clinical impact of adherent endotoxins on dental (and bone) implant devices is required in light of increasing knowledge on crosstalk between cells from the immune and skeletal systems.

  20. [Biochemistry, molecular mechanism of action and biological effects of endotoxin].

    PubMed

    Burgmann, H; Breyer, S

    1995-01-01

    This review is a brief attempt at providing an overview of a subject of enormous complexity-endotoxins and the mediators associated with its biological effects. More specifically it deals with biochemistry and biology of endotoxin, detection of endotoxin with the Limulus amebocyte lysate test, the molecular mechanisms and biological effects, and in the last part with future aspects of therapeutical strategies. It seems certain that the subject will become even more complex and possibly controversial as scientific knowledge further involves. However, because of the high mortality rate of patients suffering from gram-negative sepsis all efforts have to be made to find effective therapeutical strategies.

  1. Some metabolic effects of bacterial endotoxins in salmonid fishes

    USGS Publications Warehouse

    Wedemeyer, G.A.; Ross, A.J.; Smith, L.

    1968-01-01

    Coho salmon (Oncorhynchus kisutch) and rainbow trout (Salmo gairdneri) were highly resistant to endotoxins from both Escherichia coli and Aeromonas salmonicida (a fish pathogen) at 14 and 18 C.This resistance was investigated with liver tryptophan pyrrolase, liver glycogen depletion in vitro, and the arterial blood pressure as indicators. Liver glycogen depletion was accelerated by both endotoxins, but there was no significant cardiovascular response or effect on liver tryptophan pyrrolase activity. Since the cardiovascular effects of histamine were also limited, it was concluded that the metabolic effects of bacterial endotoxins in salmonids are qualitatively different from those of the higher vertebrates.

  2. LONG TERM EFFECTS OF PRENATAL AND POSTNATAL AIRBORNE PAH EXPOSURE ON VENTILATORY LUNG FUNCTION OF NON-ASTHMATIC PREADOLESCENT CHILDREN. PROSPECTIVE BIRTH COHORT STUDY IN KRAKOW

    PubMed Central

    Jedrychowski, Wieslaw A.; Perera, Frederica P.; Maugeri, Umberto; Majewska, Renata; Mroz, Elzbieta; Flak, Elzbieta; Camman, David; Sowa, Agata; Jacek, Ryszard

    2014-01-01

    The main goal of the study was to test the hypothesis that prenatal and postnatal exposure to polycyclic aromatic hydrocarbons (PAH) is associated with depressed lung function in non-asthmatic children. The study sample comprises 195 non-asthmatic children of non-smoking mothers, among whom the prenatal PAH exposure was assessed by personal air monitoring in pregnancy. At the age of 3, residential air monitoring was carried out to evaluate the residential PAH exposure indoors and outdoors. At the age of 5 to 8, children were given allergic skin tests for indoor allergens; and between 5–9 years lung function testing (FVC, FEV05, FEV1 and FEF25–75) was performed. The effects of prenatal PAH exposure on lung function tests repeated over the follow-up were adjusted in the General Estimated Equation (GEE) model for the relevant covariates. No association between FVC with prenatal PAH exposure was found; however for the FEV1 deficit associated with higher prenatal PAH exposure (above 37ng/m3) amounted to 53 mL (p = 0.050) and the deficit of FEF25–75 reached 164 mL (p=0.013). The corresponding deficits related to postnatal residential indoor PAH level (above 42 ng/m3) were 59 mL of FEV1 (p=0.028) and 140 mL of FEF25–75 (p=0.031). At the higher residential outdoor PAH level (above 90 ng/m3) slightly greater deficit of FEV1 (71mL, p = 0.009) was observed. The results of the study suggest that transplacental exposure to PAH compromises the normal developmental process of respiratory airways and that this effect is compounded by postnatal PAH exposure. PMID:25300014

  3. [Comparing Cell Toxicity of Schizosaccharomyces pombe Exposure to Airborne PM2.5 from Beijing and Inert Particle SiO2].

    PubMed

    Liu, Meng-jiao; Huang, Yi; Wen, Hang; Qiu, Guo-yu

    2015-11-01

    To figure out the main factor of PM2.5 toxicity to cell, this study compared the cell toxicity of Schizosaccharomyces pombe (S. pombe), a model organism, exposed to inert ultrafine SiO2 particles, a model particle, and airborne PM2.5 collected from campus of Peking University Beijing China. Using ultraviolet spectrophotometry to measure cell proliferation ratio, and environmental scanning microscope to observe the particle adhesion on the cell surface, and detecting cellular ROS generation with DHE fluorescent dye chromogenic method, and using single cell gel electrophoresis to test cell DNA damage, the experiment results indicated that the ultrafine SiO2 particles (< 60 nm) could inhibit the cell proliferation of S. pombe, mainly through adsorbing onto the cell surface to change the permeability of the cell wall; but it could not induce cells to generate ROS to cause the oxidative damage. PM2.5, the average particle size of which was larger than that of SiO2 particles, could cause oxidative damages to cells mainly by inducing cells to generate ROS, and damage DNA simultaneously. It might illustrate that there was no direct relationship between the toxicity of PM2.5 and its physical properties such as the particle size.

  4. [Comparing Cell Toxicity of Schizosaccharomyces pombe Exposure to Airborne PM2.5 from Beijing and Inert Particle SiO2].

    PubMed

    Liu, Meng-jiao; Huang, Yi; Wen, Hang; Qiu, Guo-yu

    2015-11-01

    To figure out the main factor of PM2.5 toxicity to cell, this study compared the cell toxicity of Schizosaccharomyces pombe (S. pombe), a model organism, exposed to inert ultrafine SiO2 particles, a model particle, and airborne PM2.5 collected from campus of Peking University Beijing China. Using ultraviolet spectrophotometry to measure cell proliferation ratio, and environmental scanning microscope to observe the particle adhesion on the cell surface, and detecting cellular ROS generation with DHE fluorescent dye chromogenic method, and using single cell gel electrophoresis to test cell DNA damage, the experiment results indicated that the ultrafine SiO2 particles (< 60 nm) could inhibit the cell proliferation of S. pombe, mainly through adsorbing onto the cell surface to change the permeability of the cell wall; but it could not induce cells to generate ROS to cause the oxidative damage. PM2.5, the average particle size of which was larger than that of SiO2 particles, could cause oxidative damages to cells mainly by inducing cells to generate ROS, and damage DNA simultaneously. It might illustrate that there was no direct relationship between the toxicity of PM2.5 and its physical properties such as the particle size. PMID:26910977

  5. Analytical sensitivity of air samplers based on uniform point-source exposure to airborne Porcine reproductive and respiratory syndrome virus and swine influenza virus

    PubMed Central

    Hermann, Joseph R.; Zimmerman, Jeffrey J.

    2008-01-01

    Research and surveillance activities involving airborne pathogens rely on the capture and enumeration of pathogens suspended in aerosols. The objective of this study was to estimate the analytical sensitivity (detection threshold) of each of 4 air samplers for Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SIV). In a 5-min sampling period under controlled conditions, the analytical sensitivity of the AGI-30 (Ace Glass, Vineland, New Jersey, USA), AGI-4 (Ace Glass), SKC BioSampler (SKC, Eighty Four, Pennsylvania, USA), and Midwest Micro-Tek sampler (Midwest Micro-Tek, Brookings, South Dakota, USA) was calculated at 1 × 101.1, 1 × 101.3, 1 × 101.1, and 1 × 101.2 median tissue culture infectious dose (TCID50) equivalents for PRRSV and 1 × 101.4, 1 × 101.1, 1 × 101.6, and 1 × 101.2 TCID50 equivalents for SIV [per 60 L (5-min sampling period)]. Despite marked differences in sampler design, no statistically significant difference in analytical sensitivity was detected between the samplers for collection of artificially produced aerosols containing cell-culture-propagated PRRSV or SIV. PMID:19086377

  6. Metal impurities provide useful tracers for identifying exposures to airborne single-wall carbon nanotubes released from work-related processes

    NASA Astrophysics Data System (ADS)

    Rasmussen, Pat E.; Jayawardene, Innocent; Gardner, H. David; Chénier, Marc; Levesque, Christine; Niu, Jianjun

    2013-04-01

    This study investigated the use of metal impurities in single-wall carbon nanotubes (SWCNT) as potential tracers to distinguish engineered nanomaterials from background aerosols. TEM and SEM were used to characterize parent material and aerosolized agglomerates collected on PTFE filters using a cascade impactor. SEM image analysis indicated that the SWCNT agglomerates contained about 45% amorphous carbon and backscatter electron analysis indicated that metal impurities were concentrated within the amorphous carbon component. Two elements present as impurities (Y and Ni) were selected as appropriate tracers in this case as their concentrations were found to be highly elevated in the SWCNT parent material (% range) compared to ambient air particles (μg/g range), and background air concentrations were below detection limits for both elements. Bioaccessibility was also determined using physiologically-based extractions at pH conditions relevant to both ingestion and inhalation pathways. A portable wet electrostatic precipitation system effectively captured airborne Y and Ni released during sieving processes, in proportions similar to the bulk sample. These observations support the potential for catalysts and other metal impurities in carbon nanotubes to serve as tracers that uniquely identify emissions at source, after an initial analysis to select appropriate tracers.

  7. Endotoxin-Induced Structural Transformations in Liquid Crystalline Droplets

    NASA Astrophysics Data System (ADS)

    Lin, I.-Hsin; Miller, Daniel S.; Bertics, Paul J.; Murphy, Christopher J.; de Pablo, Juan J.; Abbott, Nicholas L.

    2011-06-01

    The ordering of liquid crystals (LCs) is known to be influenced by surfaces and contaminants. Here, we report that picogram per milliliter concentrations of endotoxin in water trigger ordering transitions in micrometer-size LC droplets. The ordering transitions, which occur at surface concentrations of endotoxin that are less than 10-5 Langmuir, are not due to adsorbate-induced changes in the interfacial energy of the LC. The sensitivity of the LC to endotoxin was measured to change by six orders of magnitude with the geometry of the LC (droplet versus slab), supporting the hypothesis that interactions of endotoxin with topological defects in the LC mediate the response of the droplets. The LC ordering transitions depend strongly on glycophospholipid structure and provide new designs for responsive soft matter.

  8. Exposure assessment of workers to airborne PCDD/Fs, PCBs and PAHs at an electric arc furnace steelmaking plant in the UK.

    PubMed

    Aries, Eric; Anderson, David R; Fisher, Raymond

    2008-06-01

    Occupational exposure studies were undertaken at a UK electric arc furnace (EAF) steelmaking plant to investigate the exposure of workers via inhalation to dioxins, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene (B[a]P). Surveys were undertaken in areas including the melting shop, the casting department and a furnace control cabin. The highest concentrations of dioxins and PCBs were found inside the melting shop nearby EAFs, whereas dioxin and PCB concentrations in the casting department and inside the control cabin were significantly lower. Risk characterization was carried out by comparing the daily intake of dioxins and PCBs through inhalation with the recommended tolerable daily intake (TDI). Health risk assessments were also carried out by combining exposure data with inhalation cancer potency factors to quantify the cancer risk. For the most exposed category of workers (melting shop workers), the estimated daily intake via inhalation was 0.35 pg WHO-TEQ kg(-1) body weight (bw) in the worst case scenario. Considering that the average UK adult exposure to dioxins from the diet is 1.8 pg WHO-TEQ kg(-1) bw day(-1), the results indicated that the estimated daily intake of dioxins via inhalation at the EAF would not result in the recommended range of the TDI (1-4 pg WHO-TEQ kg(-1) bw day(-1)) being exceeded. Cancer risks for a 40-year occupational exposure period were determined by multiplying the inhalation dose by the inhalation cancer potency factor for 2,3,7,8-tetrachlorodibenzo-p-dioxin. For melting shop workers, cancer risks from exposure to dioxins and PCBs ranged from 2.05 x 10(-5) to 7.54 x 10(-5). Under most regulatory programmes, excess cancer risks between 1.0 x 10(-4) and 1.0 x 10(-6) indicate an acceptable range of excess cancer risk, suggesting a limited risk from dioxin exposure for workers in the EAF plant. For the calculation of excess cancer risks, no account has been taken of the protection

  9. Ultrasensitive detection of endotoxins using computationally designed nanoMIPs.

    PubMed

    Altintas, Zeynep; Abdin, Mohammed J; Tothill, Alexander M; Karim, Kal; Tothill, Ibtisam E

    2016-09-01

    Novel molecularly imprinted polymer nanoparticles (nanoMIPs) were designed for endotoxin from Escherichia coli 0111:B4, using computational modeling. The screening process based on binding energy between endotoxin and each monomer was performed with 21 commonly used monomers, resulting in the selection of itaconic acid, methacrylic acid and acrylamide as functional monomers due to their strong binding interaction with the endotoxin template. The nanoMIPs were successfully synthesized with functional groups on the outer surface to aid in the immobilization onto sensor surface. The solid phase photopolymerization approach used for the synthesis of nanoMIPs ranging from 200 to 235 nm in diameter. The limit of detection and KD were significantly improved when endotoxin samples were prepared using a novel triethylamine method. This improved the efficiency of gold nanoparticle functionalization by targeting the subunits of the endotoxin. Compared to the vancomycin MIP control, the endotoxin MIPs displayed outstanding affinity and selectivity towards the endotoxin with KD values in the range of 4.4-5.3 × 10(-10) M, with limits of detection of 0.44 ± 0.02 ng mL(-1) as determined by surface plasmon resonance (SPR) sensor when itaconic acid was used as the functional monomer. The MIP surface can be regenerated >30 times without significant loss of binding activity making this approach highly cost effective for expensive analyte templates. The combination of molecular modeling and solid phase synthesis enabled the successful synthesis of nanoMIPs capable of recognition and ultrasensitive detection of endotoxins using the highly sensitive SPR biosensor with triethylamine method. PMID:27543033

  10. The use of multizone models to estimate an airborne chemical contaminant generation and decay profile: occupational exposures of hairdressers to vinyl chloride in hairspray during the 1960s and 1970s.

    PubMed

    Sahmel, Jennifer; Unice, Ken; Scott, Paul; Cowan, Dallas; Paustenbach, Dennis

    2009-12-01

    Vinyl chloride (VC) was used as a propellant in a limited percentage of aerosol hairspray products in the United States from approximately 1967 to 1973. The question has arisen whether occupational exposures of hairdressers to VC-containing hairsprays in hair salons were sufficient to increase the risk for developing hepatic angiosarcoma (HAS). Transient two-zone and steady-state three-zone models were used to estimate the historical airborne concentration of VC for individual hairdressers using hairspray as well as estimated contributions from other hairdressers in the same salon. Concentrations of VC were modeled for small, medium, and large salons, as well as a representative home salon. Model inputs were determined using published literature, and variability in these inputs was also considered using Monte Carlo techniques. The 95th percentile for the daily time-weighted average exposure for small, medium, and large salons, assuming a market-share fraction of VC-containing hairspray use from the Monte Carlo analysis, was about 0.3 ppm, and for the home salon scenario was 0.1 ppm. The 95th percentile value for the cumulative lifetime exposure of the hairdressers was 2.8 ppm-years for the home salon scenario and 2.0 ppm-years for the small, medium, and large salon scenarios. If using the assumption that all hairsprays used in a salon contained VC, the 95th percentile of the theoretical lifetime cumulative dose was estimated to be 52-79 ppm-years. Estimated lifetime doses were all below the threshold dose for HAS of about 300 to 500 ppm-years reported in the published epidemiology literature.

  11. Pneumoconiosis, lung function and exposure to airborne dust: epidemiological research to compare responses of working coalminers with responses of ex-miners. Part 2. Final report

    SciTech Connect

    Soutar, C.A.; Maclaren, W.; Hurley, F.; Murdoch, R.; Hadden, G.

    1982-03-01

    The relationship between dust exposure and disease for miners was compared with that for ex-miners, in order to determine whether relationships found in other studies on miners alone could be applied to both groups. 17,738 men examined in the 1950s were followed up approximately 22 years later. Sixty one per cent of the survivors were examined, being 40% of the original sample. Records were made of respiratory symptoms, smoking habit, lung spirometry and chest radiograph findings. Radiographs were interpreted according to the International Labour Office Classification of Pneumoconiosis. Lifetime dust exposure was calculated for each subject. The dust/disease relationship was found to be the same for both groups. Ex-miners were found to have more pneumoconiosis and fibrosis and to be in worse health than miners. Pneumoconiosis progression was shown to be related to continued dust exposure; fibrosis progression was related to the presence of dust in the lungs. Dust exposure was shown to cause a mainly restrictive pattern of lung disease in contrast to the obstructive pattern caused by smoking. Colliery-related differences were found in lung disease which it was felt needed further investigation.

  12. Biopanning of endotoxin-specific phage displayed peptides.

    PubMed

    Thomas, Celestine J; Sharma, Shilpi; Kumar, Gyanendra; Visweswariah, Sandhya S; Surolia, Avadhesha

    2003-07-18

    Systemic bacterial infections frequently lead to a plethora of symptoms termed "endotoxic shock" or "sepsis." Characterized by hypotension, coagulation abnormalities, and multiple organ failure, treatment of sepsis still remains mostly supportive. Of the various experimental therapeutic interventional strategies, neutralization of endotoxin by peptides or proteins is becoming popular recently. Hence, design of endotoxin binding peptides is gaining currency as their structural complexity and mode of recognition of endotoxin precludes mounting of resistance against them by the susceptible bacteria by genetic recombination, mutation, etc. Earlier work from our laboratory had shown that the amphiphilic cationic peptides are good ligands for endotoxin binding. In this study, we report the results of studies with the 12 selected lipid A binding phage displayed peptides by biopanning of a repertoire of a random pentadecapeptide library displayed on the filamentous M-13 phage. A comparison of the sequences revealed no consensus sequence between the 12 selected peptides suggesting that the lipid A binding motif is not sequence specific which is in accord with the sequence variation seen with the naturally occurring anti-microbial and/or endotoxin binding peptides. Thus, the flexibility of the peptides coupled with their plasticity in recognizing the lipid A moiety, explains their tight binding to endotoxin. At a structural level, asymmetric distribution of the charged polar residues on one face of the helix and non-polar residues on the opposite face appears to correlate with their activity.

  13. Endotoxins-the invisible companion in biomaterials research.

    PubMed

    Lieder, Ramona; Petersen, Pétur Henry; Sigurjónsson, Ólafur Eysteinn

    2013-10-01

    Metal implants and polymeric devices for the application in the clinical treatment of orthopedic tissue injuries are increasingly coated with bioactive biomaterials derived from natural substances to induce desirable biological effects. Many metals and polymers used in biomaterials research show high affinity for endotoxins, which are abundant in the environment. Endotoxin contamination is indicated in the pathology of periodontitis and aseptic implant loosening, but may also affect the evaluation of a biomaterial's bioactivity by inducing strong inflammatory reactions. In this review, we discuss the high affinity of three commonly used implant biomaterials for endotoxins and how the contamination can affect the outcome of the orthopedic fixation. The chemical nature of bacterial endotoxins and some of the clinical health implications are described, as this knowledge is critically important to tackle the issues associated with the measurement and removal of endotoxins from medical devices. Commonly used methods for endotoxin testing and removal from natural substances are examined and the lack of standard guidelines for the in vitro evaluation of biomaterials is discussed.

  14. The Impact of Early-Life Exposure to Air-borne Environmental Insults on the Function of the Airway Epithelium in Asthma.

    PubMed

    Spann, Kirsten; Snape, Natale; Baturcam, Engin; Fantino, Emmanuelle

    2016-01-01

    The airway epithelium is both a physical barrier protecting the airways from environmental insults and a significant component of the innate immune response. There is growing evidence that exposure of the airway epithelium to environmental insults in early life may lead to permanent changes in structure and function that underlie the development of asthma. Here we review the current published evidence concerning the link between asthma and epithelial damage within the airways and identify gaps in knowledge for future studies. PMID:27325066

  15. Administration to mouse of endotoxin from gram-negative bacteria leads to activation and apoptosis of T lymphocytes.

    PubMed

    Castro, A; Bemer, V; Nóbrega, A; Coutinho, A; Truffa-Bachi, P

    1998-02-01

    Lipopolysaccharide (LPS) from gramnegative bacteria is a well-known T cell-independent B lymphocyte mitogen and macrophage/monocyte activator. While the conventional view holds that LPS is ignored by T cells, we report here that administration of LPS to mice activates all B cells, but also engages most CD4 and CD8 T cells, as measured by the expression of the activation markers CD69 and CD25 and by size increase. T cells recruited in endotoxin-treated mice showed, following in vitro stimulation by concanavalin A, altered patterns of cytokine production. In vivo, massive T cell apoptosis was evidenced in the days following LPS exposure. The present observation may contribute novel insights into the mechanisms of endotoxin shock and of the immunological consequences of gram-negative infections. PMID:9521057

  16. Endotoxin contamination of apolipoprotein A-I: effect on macrophage proliferation--a cautionary tale.

    PubMed

    Jin, Xueting; Xu, Qing; Champion, Keith; Kruth, Howard S

    2015-05-01

    This technical report addresses the problem of endotoxin contamination of apolipoprotein reagents. Using a bromodeoxyuridine incorporation cell proliferation assay, we observed that human plasma ApoA-I as low as 1 μg/ml resulted in a >90% inhibition in macrophage proliferation. However, not all ApoA-I from different sources showed this effect. We considered the possibility that endotoxin contamination of the apolipoproteins contributed to the differential inhibition of macrophage cell proliferation. Endotoxin alone very potently inhibited macrophage proliferation (0.1 ng/ml inhibited macrophage proliferation>90%). Measurement of endotoxin levels in the apolipoprotein products, including an analysis of free versus total endotoxin, the latter which included endotoxin that was masked due to binding to protein, suggested that free endotoxin mediated inhibition of macrophage proliferation. Despite the use of an advanced endotoxin removal procedure and agents commonly used to inhibit endotoxin action, the potency of endotoxin precluded successful elimination of endotoxin effect. Our findings show that endotoxin contamination can significantly influence apparent apolipoprotein-mediated cell effects (or effects of any other biological products), especially when these products are tested on highly endotoxin-sensitive cells, such as macrophages.

  17. An evaluation of the external radiation exposure dosimetry and calculation of maximum permissible concentration values for airborne materials containing 18F, 15O, 13N, 11C and 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1985-11-01

    To better understand the dose equivalent (D.E.) rates produced by airborne releases of gaseous positron-emitting radionuclides under various conditions of cloud size, a study of the external radiation exposure dosimetry of these radionuclides, as well as negatron, gamma and x-ray emitting 133Xe, was undertaken. This included a calculation of the contributions to D.E. as a function of cloud radii, at tissue depths of 0.07 mm (skin), 3 mm (lens of eye) and 10 mm (whole body) from both the particulate and photon radiations emitted by these radionuclides. Estimates of maximum permissible concentration (MPC) values were also calculated based on the calculated D.E. rates and current regulations for personnel radiation protection (CFR84). Three continuous air monitors, designed for use with 133Xe, were evaluated for applications in monitoring air concentrations of the selected positron emitters. The results indicate that for a given radionuclide and for a cloud greater than a certain radius, personnel radiation dosimeters must respond acceptably to only the photon radiations emitted by the radionuclide to provide acceptable personnel dosimetry. For clouds under that radius, personnel radiation dosimeters must also respond acceptably to the positron or negatron radiations to provide acceptable personnel dosimetry. It was found that two out of the three air concentration monitors may be useful for monitoring air concentrations of the selected positron emitters.

  18. The natural immunity to evolutionary atavistic endotoxin for human cancer.

    PubMed

    Moncevičiūtė-Eringienė, Elena; Rotkevič, Kristina; Grikienis, Ruta Grikienyte

    2015-11-01

    We propose a new theory of the immunological control of cancer corresponding to the hypothesis that the specific natural immunity to evolutionary atavistic endotoxin has a potential role in human cancer prevention. The results of our studies have shown that IgMNAE, i.e. endogenous or spontaneous IgM class antibodies to enterobacterial lipopolysaccharide molecules (lipid A), control the immune mechanisms responsible for the internal medium stability not only against the damaging impact of the carcinogenic factors, but also against the malignant transformation of its own degenerated cells. Among people who in 1979 and 1982 had IgMNAE in their blood serum, after 15-30years fell ill with cancer 10%, versus 15% among people who had no IgMNAE (p<0.05). Therefore, it is possible to maintain that the stimulation of IgMNAE synthesis would help in the destruction and elimination of damaged somatic cells or prevent their mechanisms from the formation of invasiveness, metastatic and other properties of their parasitism. In the mechanism of the natural immunity to endotoxin it is possible to see the formation of the respective evolutionary protective reactions which protect the damaged cells from acquiring resistance to damaging factors and thus from becoming an independent new parasitic population. Thereby the presented theory of the immunological control of cancer has a causal connection with our evolutionary resistance theory of the origin of cancer. Collectively, these data suggest that activation of natural immunity to endotoxin and production of vaccines against evolutionary atavistic endotoxin or gram-negative bacterial endotoxin can be helpful when applied in cancer prophylaxis for persons with a low level of natural immunity to endotoxin and perhaps in creating immunotherapeutic methods for stopping the endogenous parasitism of tumour cells by binding IgMNAE to atavistic endotoxin in cancer patients.

  19. Endotoxin increases pulmonary vascular protein permeability in the dog

    SciTech Connect

    Welsh, C.H.; Dauber, I.M.; Weil, J.V.

    1986-10-01

    Endotoxin increases pulmonary vascular permeability consistently in some species but fails to reliably cause injury in the dog. We wondered whether this phenomenon depended on the method of injury assessment, as others have relied on edema measurement; we quantified injury by monitoring the rate of extravascular protein accumulation. /sup 113m/In-labeled protein and /sup 99m/Tc-labeled erythrocytes were injected into anesthetized dogs and monitored by an externally placed lung probe. A protein leak index, the rate of extravascular protein accumulation, was derived from the rate of increase in lung protein counts corrected for changes in intravascular protein activity. After administration of Salmonella enteriditis endotoxin (4 micrograms/kg), the protein leak index was elevated 2.5-fold (41.1 +/- 4.6 X 10(-4) min-1) compared with control (16.0 +/- 2.8 X 10(-4) min-1). In contrast, wet-to-dry weight ratios failed to increase after endotoxin (4.6 +/- 0.8 vs. control values of 4.2 +/- 0.5 g/g dry bloodless lung). However, we observed that endotoxin increased lung dry weight (per unit body weight), which may have attenuated the change in wet-to-dry weight ratios. To determine whether low microvascular pressures following endotoxin attenuated edema formation, we increased pulmonary arterial wedge pressures in five dogs by saline infusion, which caused an increase in wet-to-dry weight ratios following endotoxin but no change in the five controls. We conclude that low dose endotoxin causes pulmonary vascular protein leak in the dog while edema formation is minimal or absent.

  20. Endotoxin inactivation in water by using medium-pressure UV lamps.

    PubMed

    Anderson, W B; Huck, P M; Dixon, D G; Mayfield, C I

    2003-05-01

    Deionized water was spiked with various concentrations of endotoxin and exposed to UV irradiation from medium-pressure UV lamps to assess endotoxin inactivation. It was found that endotoxin inactivation was proportional to the UV dose under the conditions examined. The inactivation rate was determined to be approximately 0.55 endotoxin unit/ml per mJ/cm(2) of irradiation delivered. PMID:12732578

  1. Puerarin ameliorates experimental alcoholic liver injury by inhibition of endotoxin gut leakage, Kupffer cell activation, and endotoxin receptors expression.

    PubMed

    Peng, Jing-Hua; Cui, Tuan; Huang, Fu; Chen, Liang; Zhao, Yu; Xu, Lin; Xu, Li-Li; Feng, Qin; Hu, Yi-Yang

    2013-03-01

    Puerarin, an isoflavone component extracted from Kudzu (Pueraria lobata), has been demonstrated to alleviate alcohol-related disorders. Our study examined whether puerarin ameliorates chronic alcoholic liver injury through inhibition of endotoxin gut leakage, the subsequent Kupffer cell activation, and endotoxin receptors expression. Rats were provided with the Liber-DeCarli liquid diet for 8 weeks. Puerarin (90 mg/kg or 180 mg/kg daily) was orally administered from the beginning of the third week until the end of the experiment. Chronic alcohol intake caused increased serum alanine aminotransferase, aspartate aminotransferase, hepatic gamma-glutamyl transpeptidase, and triglyceride levels as well as fatty liver and neutrophil infiltration in hepatic lobules as determined by biochemical and histologic assays. A significant increase of liver tumor necrosis factor α was detected by enzyme-linked immunosorbent assay. These pathologic effects correlated with increased endotoxin level in portal vein and upregulated protein expression of hepatic CD68, lipopolysaccharide-binding protein, CD14, Toll-like receptor 2, and Toll-like receptor 4. Meanwhile, the intestinal microvilli were observed to be sparse, shortened, and irregularity in distribution under the transmission electron microscope in conjunction with the downregulated intestinal zonula occludens-1 protein expression. These hepatic pathologic changes were significantly inhibited in puerarin-treated animals as were the endotoxin levels and hepatic CD68 and endotoxin receptors. Moreover, the pathologic changes in intestinal microvillus and the decreased intestinal zonula occludens-1 were also ameliorated with puerarin treatment. These results thus demonstrate that puerarin inhibition of endotoxin gut leakage, Kupffer cell activation, and endotoxin receptors expression is involved in the alleviation of chronic alcoholic liver injury in rats.

  2. Levels, indoor-outdoor relationships and exposure risks of airborne particle-associated perchlorate and chlorate in two urban areas in Eastern Asia.

    PubMed

    Yao, Lan; Yang, Lingxiao; Chen, Jianmin; Toda, Kei; Wang, Xinfeng; Zhang, Junmei; Yamasaki, Dai; Nakamura, Yukihide; Sui, Xiao; Zheng, Longfei; Wen, Liang; Xu, Caihong; Wang, Wenxing

    2015-09-01

    Indoor and outdoor concentrations of PM2.5-associated perchlorate (ClO4(-)) and chlorate (ClO3(-)) were investigated in Jinan, China, and size-resolved perchlorate and chlorate were studied in Kumamoto, Japan. The average outdoor PM2.5-associated concentrations of perchlorate and chlorate were 4.18 ng m(-3) and 2.82 ng m(-3), respectively, in Jinan. Perchlorate and chlorate were mainly distributed in fine particles, and their approximate PM2.5-associated concentrations were 0.04 ng m(-3) and 4.14 ng m(-3), respectively, in Kumamoto. The ratios of ClO3(-)/ClO4(-) ranged from 18.72 to 360.22 in Kumamoto and from 0.03 to 7.45 in Jinan. The highest concentration of perchlorate (173.76 ng m(-3)) was observed on Spring Festival Eve. This finding and the significant correlation between perchlorate and fireworks-related components (Cl(-) and K(+)) indicated that the fireworks display was a significant source of perchlorate in Jinan. The indoor concentrations of perchlorate and chlorate in Jinan were 3.54 ng m(-3) (range, 0.14-125.14 ng m(-3)) and 0.94 ng m(-3) (range, 0.10-1.80 ng m(-3)), respectively. In the absence of an indoor source of perchlorate, the occurrence of indoor concentrations higher than those found outdoors was a common effect of individual fireworks displays near the sampling sites, coupled with meteorological influences and poor indoor diffusion conditions. The exposure risks of perchlorate and chlorate indoors indicated that the potential risk of perchlorate exposure to children during fireworks displays is deserving of concern.

  3. Levels, indoor-outdoor relationships and exposure risks of airborne particle-associated perchlorate and chlorate in two urban areas in Eastern Asia.

    PubMed

    Yao, Lan; Yang, Lingxiao; Chen, Jianmin; Toda, Kei; Wang, Xinfeng; Zhang, Junmei; Yamasaki, Dai; Nakamura, Yukihide; Sui, Xiao; Zheng, Longfei; Wen, Liang; Xu, Caihong; Wang, Wenxing

    2015-09-01

    Indoor and outdoor concentrations of PM2.5-associated perchlorate (ClO4(-)) and chlorate (ClO3(-)) were investigated in Jinan, China, and size-resolved perchlorate and chlorate were studied in Kumamoto, Japan. The average outdoor PM2.5-associated concentrations of perchlorate and chlorate were 4.18 ng m(-3) and 2.82 ng m(-3), respectively, in Jinan. Perchlorate and chlorate were mainly distributed in fine particles, and their approximate PM2.5-associated concentrations were 0.04 ng m(-3) and 4.14 ng m(-3), respectively, in Kumamoto. The ratios of ClO3(-)/ClO4(-) ranged from 18.72 to 360.22 in Kumamoto and from 0.03 to 7.45 in Jinan. The highest concentration of perchlorate (173.76 ng m(-3)) was observed on Spring Festival Eve. This finding and the significant correlation between perchlorate and fireworks-related components (Cl(-) and K(+)) indicated that the fireworks display was a significant source of perchlorate in Jinan. The indoor concentrations of perchlorate and chlorate in Jinan were 3.54 ng m(-3) (range, 0.14-125.14 ng m(-3)) and 0.94 ng m(-3) (range, 0.10-1.80 ng m(-3)), respectively. In the absence of an indoor source of perchlorate, the occurrence of indoor concentrations higher than those found outdoors was a common effect of individual fireworks displays near the sampling sites, coupled with meteorological influences and poor indoor diffusion conditions. The exposure risks of perchlorate and chlorate indoors indicated that the potential risk of perchlorate exposure to children during fireworks displays is deserving of concern. PMID:25898387

  4. Harnessing aptamers for electrochemical detection of endotoxin.

    PubMed

    Kim, Sung-Eun; Su, Wenqiong; Cho, MiSuk; Lee, Youngkwan; Choe, Woo-Seok

    2012-05-01

    Lipopolysaccharide (LPS), also known as endotoxin, triggers a fatal septic shock; therefore, fast and accurate detection of LPS from a complex milieu is of primary importance. Several LPS affinity binders have been reported so far but few of them have proved their efficacy in developing electrochemical sensors capable of selectively detecting LPS from crude biological liquors. In this study, we identified 10 different single-stranded DNA aptamers showing specific affinity to LPS with dissociation constants (K(d)) in the nanomolar range using a NECEEM-based non-SELEX method. Based on the sequence and secondary structure analysis of the LPS binding aptamers, an aptamer exhibiting the highest affinity to LPS (i.e., B2) was selected to construct an impedance biosensor on a gold surface. The developed electrochemical aptasensor showed excellent sensitivity and specificity in the linear detection range from 0.01 to 1 ng/mL of LPS with significantly reduced detection time compared with the traditional Limulus amoebocyte lysate (LAL) assay. PMID:22370280

  5. The Biomarkers of Exposure and Effect in Agriculture (BEEA) Study: Rationale, design, methods, and participant characteristics

    EPA Science Inventory

    Agricultural exposures including pesticides, endotoxin, and allergens have been associated with risk of various cancers and other chronic diseases, although the biological mechanisms underlying these associations are generally unclear. To facilitate future molecular epidemiologic...

  6. Omega-3 fatty acids modulate neonatal cytokine response to endotoxin.

    PubMed

    Espiritu, Michael M; Lin, Hong; Foley, Elizabeth; Tsang, Valerie; Rhee, Eunice; Perlman, Jeffrey; Cunningham-Rundles, Susanna

    2016-08-01

    Neonatal immune response is characterized by an uncompensated pro-inflammatory response that can lead to inflammation-related morbidity and increased susceptibility to infection. We investigated the effects of long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) pre-treatment on cytokine secretion to low-concentration endotoxin (lipopolysaccharide, LPS) in THP-1 monocytes and neonatal cord blood (CB) from healthy full-term infants. Pre-treatment of THP-1 cells, with either n-3 PUFA at 25 or 100 μM significantly reduced IL-6, IL-10, and IL-12 secretion while DHA, but not EPA, reduced TNF-α response to LPS. DHA inhibition was stronger compared to EPA and effective at the low concentration. The same concentrations of n-3 PUFAs inhibited IL-12 but not IL-10 cytokine response in whole CB from 9 infants pre-treated for 24 h. To assess clinical relevance for acute response to LPS, the effects of low-concentration DHA at 25 μM or 12.5 μM were assessed before and after LPS exposure of isolated CB mononuclear cells from 20 infants for 1 h. When added before or after LPS, physiologic DHA treatment produced significant concentration-dependent inhibition of TNF-α, IL-6, IL-1β, and IL-8 secretion. The results demonstrate prophylactic and therapeutic modulation of neonatal cytokine response to LPS and provide proof-of-concept that low-concentration administration of n-3 PUFA could attenuate or resolve neonatal inflammatory response.

  7. 40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Delta endotoxin of Bacillus... From Tolerances § 180.1107 Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin...

  8. 40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Delta endotoxin of Bacillus... From Tolerances § 180.1107 Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin...

  9. 40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Delta endotoxin of Bacillus... From Tolerances § 180.1107 Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin...

  10. Sampling and composition of airborne particulate matter (PM10) from two locations of Mexico City

    PubMed Central

    Chirino, Yolanda I.; Sánchez-Pérez, Yesennia; Osornio-Vargas, Álvaro Román; Rosas, Irma; García-Cuellar, Claudia María

    2015-01-01

    The PM10 airborne particulate matter with an aerodynamic diameter ≤10 µm is considered as a risk factor of various adverse health outcomes, including lung cancer. Here we described the sampling and composition of PM10 collected from an industrial zone (IZ), and a commercial zone (CZ) of Mexico City. The PM10 was collected with a high-volume sampler in the above mentioned locations and both types of PM10 sampled were characterized by the content of polycyclic aromatic hydrocarbons (PAHs), metals, and endotoxin. The endotoxin PM10 content from IZ and CZ displayed 138.4 UE/mg and 170.4 UE/mg of PM10, respectively. PMID:26217815

  11. Sampling and composition of airborne particulate matter (PM10) from two locations of Mexico City.

    PubMed

    Chirino, Yolanda I; Sánchez-Pérez, Yesennia; Osornio-Vargas, Álvaro Román; Rosas, Irma; García-Cuellar, Claudia María

    2015-09-01

    The PM10 airborne particulate matter with an aerodynamic diameter ≤10 µm is considered as a risk factor of various adverse health outcomes, including lung cancer. Here we described the sampling and composition of PM10 collected from an industrial zone (IZ), and a commercial zone (CZ) of Mexico City. The PM10 was collected with a high-volume sampler in the above mentioned locations and both types of PM10 sampled were characterized by the content of polycyclic aromatic hydrocarbons (PAHs), metals, and endotoxin. The endotoxin PM10 content from IZ and CZ displayed 138.4 UE/mg and 170.4 UE/mg of PM10, respectively.

  12. Symptomatic Effects of Exposure to Diluted Air Sampled from a Swine Confinement Atmosphere on Healthy Human Subjects

    PubMed Central

    Schiffman, Susan S.; Studwell, Clare E.; Landerman, Lawrence R.; Berman, Katherine; Sundy, John S.

    2005-01-01

    Aerial emissions from a swine house at North Carolina State University’s field laboratory were diluted to a level that could occur at varying distances downwind from a confined animal feeding operation (CAFO) both within and beyond the property line, and these emissions were delivered to an environmental exposure chamber. The study design consisted of two 1-hr sessions, one in which 48 healthy human adult volunteers were exposed to diluted swine air and another in which they were exposed to clean air (control). Objective measures of blood pressure, temperature, heart rate, respiratory rate, lung function, nasal inflammation, secretory immunity, mood, attention, and memory were correlated with objective measures of air quality. Ratings of perceived (self-reported) health symptoms were also obtained. The mean levels of airborne constituents in the swine air condition were hydrogen sulfide (24 ppb), ammonia (817 ppb), total suspended particulates (0.0241 mg/m3), endotoxin (7.40 endotoxin units/m3), and odor (57 times above odor threshold). No statistical differences on objective measures of physical symptoms, mood, or attention resulted from the 1-hr exposure to swine emissions in the environmental chamber when compared with clean air for healthy human volunteers. However, subjects were 4.1 (p = 0.001) times more likely to report headaches, 6.1 (p = 0.004) times more likely to report eye irritation, and 7.8 (p = 0.014) times more likely to report nausea in the swine air (experimental) condition than in the control condition. These results indicate that short-term exposure in an environmental chamber to malodorous emissions from a swine house at levels expected downwind can induce clinically important symptoms in healthy human volunteers. PMID:15866765

  13. Symptomatic effects of exposure to diluted air sampled from a swine confinement atmosphere on healthy human subjects.

    PubMed

    Schiffman, Susan S; Studwell, Clare E; Landerman, Lawrence R; Berman, Katherine; Sundy, John S

    2005-05-01

    Aerial emissions from a swine house at North Carolina State University's field laboratory were diluted to a level that could occur at varying distances downwind from a confined animal feeding operation (CAFO) both within and beyond the property line, and these emissions were delivered to an environmental exposure chamber. The study design consisted of two 1-hr sessions, one in which 48 healthy human adult volunteers were exposed to diluted swine air and another in which they were exposed to clean air (control). Objective measures of blood pressure, temperature, heart rate, respiratory rate, lung function, nasal inflammation, secretory immunity, mood, attention, and memory were correlated with objective measures of air quality. Ratings of perceived (self-reported) health symptoms were also obtained. The mean levels of airborne constituents in the swine air condition were hydrogen sulfide (24 ppb), ammonia (817 ppb), total suspended particulates (0.0241 mg/m3), endotoxin (7.40 endotoxin units/m3), and odor (57 times above odor threshold). No statistical differences on objective measures of physical symptoms, mood, or attention resulted from the 1-hr exposure to swine emissions in the environmental chamber when compared with clean air for healthy human volunteers. However, subjects were 4.1 (p = 0.001) times more likely to report headaches, 6.1 (p = 0.004) times more likely to report eye irritation, and 7.8 (p = 0.014) times more likely to report nausea in the swine air (experimental) condition than in the control condition. These results indicate that short-term exposure in an environmental chamber to malodorous emissions from a swine house at levels expected downwind can induce clinically important symptoms in healthy human volunteers. PMID:15866765

  14. Size-fractionated PM10 monitoring in relation to the contribution of endotoxins in different polluted areas

    NASA Astrophysics Data System (ADS)

    Traversi, D.; Alessandria, L.; Schilirò, T.; Gilli, G.

    2011-07-01

    Particulate pollution is an environmental concern that is widespread and difficult to resolve. Recently various regulatory improvements around the world have been agreed upon to tackle this problem, especially as related to the fine fraction of particulates, which more closely correlates to human health effects than other fractions. The size-fractionation of inhalable particles and their organic composition represent a new area of research that has been poorly explored thus far. Endotoxins are a type of natural organic compound that can be found in particulate matter. They are correlated with Gram-negative bacterial contamination. Health outcomes associated with exposure to these toxins are not specific and often overlap with the health effects of PM (Particulate Matter) exposure, including asthma, bronchitis, acute respiratory distress syndrome and organic dust toxic syndrome. Very little information is available on the endotoxin distribution in different PM10 size fractions. This study examined PM10 size fractions and their endotoxin content. Sampling was conducted at five different locations: one urban, two rural and two rural sites that were highly influenced by large-scale farm animal production facilities. For each location, six different PM10 fractions were evaluated. PM10 sub-fractions were categorised as follows: PM 10-7.2 (1.15-31.30 μg m -3); PM 7.2-3.0 (1.86-30.73 μg m -3); PM 3.0-1.5 (1.74-13.90 μg m -3); PM 1.5-0.95 (0.24-10.57 μg m -3); PM 0.95-0.49 (1.22-14.33 μg m -3) and PM <0.49 (13.15-85.49 μg m -3). The ranges of endotoxin levels determined were: PM 10-7.2 (0.051-5.401 endotoxin units (EU) m -3); PM 7.2-3.0 (0.123-7.801 EU m -3); PM 3.0-1.5 (0.057-1.635 EU m -3); PM 1.5-0.95 (0.040-2.477 EU m -3); PM 0.95-0.49 (0.007-3.159 EU m -3) and PM <0.49 (0.039-3.975 EU m -3). Our results indicated consistency of the PM1 fraction at all of the sites and the predominant presence of endotoxins in the coarse fraction. The observed abatement of the PM

  15. Effects of coupled dose and rhythm manipulation of plasma cortisol levels on leukocyte transcriptional response to endotoxin challenge in humans.

    PubMed

    Kamisoglu, Kubra; Sleight, Kirsten; Nguyen, Tung T; Calvano, Steve E; Coyle, Susette M; Corbett, Siobhan A; Androulakis, Ioannis P

    2014-10-01

    Severe traumas are associated with hypercortisolemia due to both disruption of cortisol secretion rhythm and increase in its total concentration. Understanding the effects of altered cortisol levels and rhythms on immune function is of great clinical interest, to prevent conditions such as sepsis from complicating the recovery. This in vivo study assesses the responses of circulating leukocytes to coupled dose and rhythm manipulation of cortisol, preceding an immune challenge induced by endotoxin administration. Through continuous infusion, plasma cortisol concentration was increased to and kept constant at a level associated with major physiologic stress. In response, transcriptional programming of leukocytes was altered to display a priming response before endotoxin exposure. Enhanced expression of a number of receptors and signaling proteins, as well as lowered protein translation and mitochondrial function indicated a sensitization against potential infectious threats. Despite these changes, response to endotoxin followed very similar patterns in both cortisol and saline pre-treated groups except one cluster including probe sets associated with major players regulating inflammatory response. In sum, altered dose and rhythm of plasma cortisol levels engendered priming of circulating leukocytes when preceded an immune challenge. This transcriptional program change associated with stimulated surveillance function and suppressed energy-intensive processes, emphasized permissive actions of cortisol on immune function.

  16. Aerosolization of fungi, (1→3)-β-D glucan, and endotoxin from flood-affected materials collected in New Orleans homes

    PubMed Central

    Adhikari, Atin; Jung, Jaehee; Reponen, Tiina; Lewis, Jocelyn Suzanne; DeGrasse, Enjoli C.; Grimsley, L. Faye; Chew, Ginger L.; Grinshpun, Sergey A.

    2015-01-01

    Standing water and sediments remaining on flood-affected materials were the breeding ground for many microorganisms in flooded homes following Hurricane Katrina. The purpose of this laboratory study was to examine the aerosolization of culturable and total fungi, (1→3)-β-D glucan, and endotoxin from eight flood-affected floor and bedding materials collected in New Orleans homes, following Hurricane Katrina. Aerosolization was examined using the Fungal Spore Source Strength Tester (FSSST) connected to a BioSampler. Dust samples were collected by vacuuming. A two-stage cyclone sampler was used for size-selective analysis of aerosolized glucan and endotoxin. On average, levels of culturable fungi ranged from undetectable (lower limit = 8.3×104) to 2.6×105 CFU/m2; total fungi ranged from 2.07×105 to 1.6×106 spores/m2; (1→3)-β-D glucan and endotoxin were 2.0×103 – 2.9×104 ng/m2 and 7.0×102 – 9.3×104 EU/m2, respectively. The results showed that 5–15 min sampling is sufficient for detecting aerosolizable biocontaminants with the FSSST. Smaller particle size fractions (<1.0 μm and <1.8 μm) have levels of glucan and endotoxin comparable to larger (>1.8 μm) fractions, which raises additional exposure concerns. Vacuuming was found to overestimate inhalation exposure risks by a factor of approximately 102 for (1→3)-β-D glucan and by 103 to 104 for endotoxin as detected by the FSSST. The information generated from this study is important with respect to restoration and rejuvenation of the flood-affected areas in New Orleans. We believe the findings will be significant during similar disasters in other regions of the world including major coastal floods from tsunamis. PMID:19201399

  17. Endotoxin impairs the human pacemaker current If.

    PubMed

    Zorn-Pauly, Klaus; Pelzmann, Brigitte; Lang, Petra; Mächler, Heinrich; Schmidt, Hendrik; Ebelt, Henning; Werdan, Karl; Koidl, Bernd; Müller-Werdan, Ursula

    2007-12-01

    LPSs trigger the development of sepsis by gram-negative bacteria and cause a variety of biological effects on host cells, including alterations on ionic channels. Because heart rate variability is reduced in human sepsis and endotoxemia, we hypothesized that LPS affects the pacemaker current I(f) in human heart, which might--at least in part--explain this phenomenon. Isolated human myocytes from right atrial appendages were incubated for 6 to 10 h with LPS (1 and 10 microg/mL) and afterwards used to investigate the pacemaker current I(f). I(f) was measured with the whole-cell patch-clamp technique (at 37 degrees C). Incubation of atrial myocytes with 10 microg/mL LPS was found to significantly impair I(f) by suppressing the current at membrane potentials positive to -80 mV and slowing down current activation, but without effecting maximal current conductance. Furthermore, in incubated cells (10 microg/mL), the response of I(f) to [beta]-adrenergic stimulation (1 microM isoproterenol) was significantly larger compared with control cells (shift of half-maximal activation voltage to more positive potentials amounted to -10 and -14 mV in untreated and treated cells, respectively). Simulations using a spontaneously active sinoatrial cell model demonstrated that LPS-induced I(f) impairment reduced the responsiveness of the model cell to fluctuations of autonomic input. This study showed a direct impact of LPS on the cardiac pacemaker current I(f). The LPS-induced I(f) impairment may contribute to the clinically observed reduction in heart rate variability under septic conditions and in cardiac diseases such as heart failure, where endotoxin can be of pathophysiological relevance.

  18. Source identification analysis for the airborne bacteria and fungi using a biomarker approach

    NASA Astrophysics Data System (ADS)

    Lee, Alex K. Y.; Lau, Arthur P. S.; Cheng, Jessica Y. W.; Fang, Ming; Chan, Chak K.

    Our recent studies have reported the feasibility of employing the 3-hydoxy fatty acids (3-OH FAs) and ergosterol as biomarkers to determine the loading of the airborne endotoxin from the Gram-negative bacteria and fungal biomass in atmospheric aerosols, respectively [Lee, A.K.Y., Chan, C.K., Fang, K., Lau, A.P.S., 2004. The 3-hydroxy fatty acids as biomarkers for quantification and characterization of endotoxins and Gram-negative bacteria in atmospheric aerosols in Hong Kong. Atmospheric Environment 38, 6807-6317; Lau, A.P.S., Lee, A.K.Y., Chan, C.K., Fang, K., 2006. Ergosterol as a biomarker for the quantification of the fungal biomass in atmospheric aerosols. Atmospheric Environment 40, 249-259]. These quantified biomarkers do not, however, provide information on their sources. In this study, the year-long dataset of the endotoxin and ergosterol measured in Hong Kong was integrated with the common water-soluble inorganic ions for source identification through the principal component analysis (PCA) and backward air mass trajectory analysis. In the coarse particles (PM 2.5-10), the bacterial endotoxin is loaded in the same factor group with Ca 2+ and accounted for about 20% of the total variance of the PCA. This implies the crustal origin for the airborne bacterial assemblage. The fungal ergosterol in the coarse particles (PM 2.5-10) had by itself loaded in a factor group of 10.8% of the total variance in one of the sampling sites with large area of natural vegetative coverage. This suggests the single entity nature of the fungal spores and their independent emission to the ambient air upon maturation of their vegetative growth. In the fine particles (endotoxin and ergosterol associated closely with K + and accounted for 34-38% of the total variance in the two sites studied. The K +/Na + ratio is indicative of the possible sources of K +, which in turn, provides information on the sources of the associated endotoxin and ergosterol. High K +/Na

  19. Effect of endotoxin and radio-detoxified endotoxin on the serum T4 level of rats and response of their thyroid gland to exogenous TSH

    SciTech Connect

    Bertok, L.; Nagy, S.U.

    1984-12-01

    Experiments were performed to demonstrate that, while the shock-inducing dose of parent (toxic) endotoxin significantly decreases the serum T4 level of rats and inhibits the T4 response given to exogenous thyroid stimulating hormone (TSH), the radio-detoxified (/sup 60/Co-gamma, 150 kGy) endotoxin preparation does not inhibit the response to exogenous TSH. It also decreases serum T4 level to a lesser extent than untreated endotoxin.

  20. Distribution of radiolabeled endotoxin with particular reference to the eye: concise communication

    SciTech Connect

    Rosenbaum, J.T.; Hendricks, P.A.; Shively, J.E.; McDougall, I.R.

    1983-01-01

    A single systemic injection of endotoxin (lipopolysaccharide or LPS) reproducibly induces a cellular infiltrate in the uveal tract of the rat eye within 24 hr. Other organs are not comparably sensitive to systemic endotoxin. One hypothesis to explain this unique sensitivity is that endotoxin is preferentially bound by ocular tissue. Researchers tested this hypothesis by studying the distribution in the rat of intravenously injected endotoxin that had been radiolabeled with /sup 99m/Tc or /sup 32/P. With either radionuclide the concentration of endotoxin per gram of tissue at a variety of times after injection ranging from 5 min to 3 hr and 45 min, was markedly less in the eye than in liver, kidney, or spleen. A study with radiolabeled albumin indicated that these differences could not be ascribed solely to the organ's blood volume. They demonstrate, therefore, that the eye does not preferentially bind endotoxin, and they are compatible with the hypothesis that endotoxin's ocular effects are indirectly mediated.

  1. Binding of /sup 125/I-labeled endotoxin to bovine, canine, and equine platelets and endotoxin-induced agglutination of canine platelets

    SciTech Connect

    Meyers, K.M.; Boehme, M.; Inbar, O.

    1982-10-01

    Endotoxin from Escherichia coli O127:B8, Salmonella abortus-equi and S minnesota induced clumping of some canine platelets (PLT) at a final endotoxin concentration of 1 microgram/ml. Endotoxin-induced clumping of canine PLT was independent of PLT energy-requiring processes, because clumping was observed with canine PLT incubated with 2-deoxy-D-glucose and antimycin A. The PLT responded to adenosine diphosphate before, but not after, incubation with the metabolic inhibitors. Endotoxin induced a slight and inconsistant clumping of bovine and equine PLT at high (mg/ml) endotoxin concentration. High-affinity binding sites could not be demonstrated on canine, bovine, and equine PLT, using /sup 125/I-labeled E coli O127:B8 endotoxin. Nonspecific binding was observed and appeared to be due primarily to an extraneous coat on the PLT surface that was removed by gel filtration. The endotoxin that was bound to PLT did not appear to modify PLT function. An attempt to identify plasma proteins that bound physiologically relevant amounts of endotoxin was not successful. The significance of the endotoxin-induced clumping or lack of it on the pathophysiology of endotoxemia is discussed.

  2. Endotoxin contamination and control in surface water sources and a drinking water treatment plant in Beijing, China.

    PubMed

    Can, Zhang; Wenjun, Liu; Wen, Sun; Minglu, Zhang; Lingjia, Qian; Cuiping, Li; Fang, Tian

    2013-07-01

    In this paper, endotoxin contamination was determined in treated water following each unit of a drinking water treatment plant (WTP) in Beijing, China and its source water (SW) from a long water diversion channel (Shijiazhuang-Beijing) originating from four reservoirs in Hebei province, China. The total-endotoxin activities in SW ranged from 21 to 41 EU/ml at five selected cross sections of the diversion channel. The total-endotoxin in raw water of the WTP ranged from 11 to 16 EU/ml due to dilution and pretreatment during water transportation from Tuancheng Lake to the WTP, and finished water of the WTP ranged from 4 to 10 EU/ml, showing a 49% decrease following the full-scale treatment process at the WTP. Compared with the 31% removal of free-endotoxin, the WTP removed up to 71% of bound-endotoxin in raw water. The traditional treatment processes (coagulation, sedimentation and filtration) in the WTP removed substantial amounts of total-endotoxin (up to 63%), while endotoxin activities increased after granular activated carbon (GAC) adsorption and chlorination. The total-endotoxin in the actual water was composed of free-endotoxin and bound-endotoxin (endotoxin aggregates, bacteria-bound endotoxins and particle-attached endotoxins). The endotoxin aggregates, bacteria-bound endotoxins and particle-attached endotoxins co-exist as suspended particles in water, and only the bacteria-bound endotoxins were correlated with bacterial cells suspended in water. The particle distribution of endotoxin aggregates in ultrapure water was also tested and the results showed that the majority (64-89%) of endotoxin aggregates had diameters <2 μm. The endotoxin contamination and control in treated water following each unit of the WTP processes and its SW from reservoirs are discussed and compared with regard to bacterial cell counts and particle characteristics, which were dependent, to a certain extent, on different flow rates and turbulence of the water environments.

  3. Mars Airborne Prospecting Spectrometer

    NASA Astrophysics Data System (ADS)

    Steinkraus, J. M.; Wright, M. W.; Rheingans, B. E.; Steinkraus, D. E.; George, W. P.; Aljabri, A.; Hall, J. L.; Scott, D. C.

    2012-06-01

    One novel approach towards addressing the need for innovative instrumentation and investigation approaches is the integration of a suite of four spectrometer systems to form the Mars Airborne Prospecting Spectrometers (MAPS) for prospecting on Mars.

  4. Streptomycetes in house dust: associations with housing characteristics and endotoxin

    EPA Science Inventory

    In addition to mold, indoor bioaerosols also contain bacterial components that may have implications for human health. Endotoxin is a cell wall component in Gram-negative bacteria present at varying levels indoors that has been found to have respiratory health implications. Stre...

  5. Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin

    NASA Astrophysics Data System (ADS)

    Borovikova, Lyudmila V.; Ivanova, Svetlana; Zhang, Minghuang; Yang, Huan; Botchkina, Galina I.; Watkins, Linda R.; Wang, Haichao; Abumrad, Naji; Eaton, John W.; Tracey, Kevin J.

    2000-05-01

    Vertebrates achieve internal homeostasis during infection or injury by balancing the activities of proinflammatory and anti-inflammatory pathways. Endotoxin (lipopolysaccharide), produced by all gram-negative bacteria, activates macrophages to release cytokines that are potentially lethal. The central nervous system regulates systemic inflammatory responses to endotoxin through humoral mechanisms. Activation of afferent vagus nerve fibres by endotoxin or cytokines stimulates hypothalamic-pituitary-adrenal anti-inflammatory responses. However, comparatively little is known about the role of efferent vagus nerve signalling in modulating inflammation. Here, we describe a previously unrecognized, parasympathetic anti-inflammatory pathway by which the brain modulates systemic inflammatory responses to endotoxin. Acetylcholine, the principle vagal neurotransmitter, significantly attenuated the release of cytokines (tumour necrosis factor (TNF), interleukin (IL)-1β, IL-6 and IL-18), but not the anti-inflammatory cytokine IL-10, in lipopolysaccharide-stimulated human macrophage cultures. Direct electrical stimulation of the peripheral vagus nerve in vivo during lethal endotoxaemia in rats inhibited TNF synthesis in liver, attenuated peak serum TNF amounts, and prevented the development of shock.

  6. Resistance of MMP9 and TIMP1 to endotoxin tolerance.

    PubMed

    Muthukuru, Manoj; Cutler, Christopher W

    2015-07-01

    Inflammatory cytokines activate tissue collagenases such as matrix metalloproteinases (MMPs). MMPs are antagonized by tissue inhibitors of metalloproteinases (TIMPs) that attempt to regulate excessive collagenase activity during inflammatory conditions. During chronic inflammatory conditions, induction of endotoxin tolerance negatively regulates the cytokine response in an attempt to curtail excessive host tissue damage. However, little is known about how downregulation of inflammatory cytokines during endotoxin tolerance regulates MMP activities. In this study, human monocyte-derived macrophages were either sensitized or further challenged to induce tolerance with lipopolysaccharide (LPS) from Porphyromonas gingivalis (PgLPS) or Escherichia coli (EcLPS). Inflammatory cytokines, such as TNF-α and IL-1β, and levels of MMP9 and TIMP1 were analyzed by a combination of cytometric bead array, western blot/gelatin zymography and real-time RT-PCR. Functional blocking with anti-TLR4 but not with anti-TLR2 significantly downregulated TNF-α and IL-1β. However, MMP9 levels were not inhibited by toll-like receptor (TLR) blocking. Interestingly, endotoxin tolerance significantly upregulated TIMP1 relative to MMP9 and downmodulated MMP9 secretion and its enzymatic activity. These results suggest that regulatory mechanisms such as induction of endotoxin tolerance could inhibit MMP activities and could facilitate restoring host tissue homeostasis.

  7. [The importance of endotoxin producing bacterias for practical purposes

    PubMed

    Schimmel, Dietrich

    1994-01-01

    Lipopolysaccharides (endotoxin) cause according to resorption out of the intestinal tract or aerogenic inhalation or by a septic infection clinical signs. The clinical reactions are praeshock symptoms, acute forms of shock and death. The experimental intratracheally administration of lipopolysaccharides into calves caused pneumonic lesions without bacterial experimental infection.

  8. Endotoxin-induced mortality in rats is reduced by nitrones

    SciTech Connect

    Hamburger, S.A.; McCay, P.B. )

    1989-12-01

    The goal of these investigations was to determine if nitrone spin-trapping agents can alter mortality associated with endotoxemia in the rat. Reactive free radicals attack nitrone spin-trapping agents forming relatively reactive, persistent free radical spin adducts. We administered 85 mM (10 ml/kg) of alpha-phenyl N-tert-butyl nitrone (PBN), alpha-4-pyridyl-N-oxide N-tert-butyl nitrone (4-POBN), 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), or vehicle (saline i.p.) 30 min before endotoxin (25 mg/kg i.p.) or vehicle to Sprague-Dawley (SD) or Holtzman virus-free (HVF) rats (n = 10-17/group). All vehicle-treated rats receiving endotoxin were dead by 1 day. At 7 days, 83% of PBN-treated SD, 42% of PBN- or POBN-treated HVF, and 25% of DMPO-treated HVF rats were alive. The difference in survival of PBN-treated animals between strains may reflect the higher susceptibility of HVF rats to endotoxin. The observed reduction in mortality may be related to the well-established capacity of spin-trapping agents to capture reactive free radicals that may be generated in target tissues in response to endotoxin, and that would otherwise react with cell components and produce tissue injury.

  9. [Endotoxin Is a Companent in Pathogenesis of Chronic Viral Diseases].

    PubMed

    Anikhovskaya, I; Kubatiev, A; Khasanova, G; Yakovlev, M

    2015-01-01

    The level of endotoxin and indicators of activity of antiendotoxin immunity (antibody concentration to glycolipid Re-chemotype and general antigen of enterobacteria) were estimated in serum of 174 patients with persistent viral infections (viruses: herpes simplex, hepatitis C, human immunodeficiency). The presence of markers of systemic inflammatory response syndrome (interleukin IL-1β) and acquired immunodeficiency (CD4+) in HIV-infected patients were also determined. Persistent viral infections are accompanied by endotoxin aggression intestinal origin (caused by them), which is able to induce the development of systemic inflammatory response syndrome. In HIV-infected patients with this syndrome is cyclical, when the phase of hyperactivity replaced immunodeficiency. Schematically, this process can be represented as the following sequence of events: HIV-mediated damage to the intestinal barrier--the development of endotoxin aggression--induction ofsystemic inflammatory response syndrome--the depletion of the immune system, which is transient and is related to the duration of activity of the virus replication cycle, i.e., with damage to enterocytes. Using antiendotoxin component (means of reducing levels of endotoxin in the blood) in the scheme of treatment of persistent viral infections can serve as an element of a successful prevention of complications. PMID:26237956

  10. Endotoxin recovery using limulus amebocyte lysate (LAL) assay.

    PubMed

    Bolden, Jay S; Warburton, Rob E; Phelan, Robert; Murphy, Marie; Smith, Kelly R; De Felippis, Michael R; Chen, Dayue

    2016-09-01

    A phenomenon initially reported by Chen and Vinther in 2013 [1], and now commonly referred to as low endotoxin recovery (LER), has prompted the Food and Drug Administration (FDA) to request specific data demonstrating the capability of the LAL BET method (i.e., USP <85>) to recover endotoxin from spiked samples over time. The results of these spike/hold recovery studies are expected to be included in the Biologics License Applications (BLA) for review by the Center for Drug Evaluation and Research (CDER) Hughes (2014) and Hughes et al. (2015) [2,3]. Such studies involve spiking a known amount of a surrogate endotoxin, such as purified lipopolysaccharide (LPS), into undiluted biological products and then testing at different time points to determine the recovery over time. We report here the experience and learning gained from conducting spike/hold recovery studies for a monoclonal antibody (Mab) product. Results from initial hold studies spiked with purified LPS showed rapid loss of endotoxin activity in the drug substance (DS) and significant batch-to-batch variation in the drug product (DP). After careful review and examination of the experimental details, it was determined that the study design and execution differed from the routine batch release USP <85> BET method with regard to mixing time and sampling scheme. The hold study design was subsequently revised so that the mixing time and sampling were the same as the verified USP <85> BET method used for routine batch release testing. The spike/hold recovery studies were repeated and the results demonstrated that LPS could be consistently recovered over time. These findings highlight the importance of carefully controlling sample preparation procedures in a spike/hold recovery study in order to demonstrate the suitability of using the LAL BET method for endotoxin detection. PMID:27470947

  11. Endotoxins in Environmental and Clinical Samples Assessed by GC-Tandem MS

    NASA Astrophysics Data System (ADS)

    Szponar, Bogumila

    Bacteria appeared on the Earth millions years before us and human evolution was triggered by the constant presence of pathogenic and symbiotic microorganisms in our surroundings. Interplay occurred between higher organism and microbial consortia residing in the host organs and on the epithelial surfaces; another natural space of bacteria-human interaction is the indoor environment where we spend the majority of our lifetime. Indoor microbial exposure affects our well-being and can result in respiratory symptoms, such as allergies and asthma, since both dead and live microorganisms and their cell constituents, including lipopolysaccharides (LPS, endotoxins), interact with our immune system. Thus, there is a demand for robust tools for qualitative and quantitative determination of the microbial communities that we are exposed to.

  12. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.L.; Keiswetter, D.

    1995-12-31

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

  13. Endotoxin depletion of recombinant protein preparations through their preferential binding to histidine tags.

    PubMed

    Mack, Laura; Brill, Boris; Delis, Natalia; Groner, Bernd

    2014-12-01

    The presence of endotoxins in preparations of recombinantly produced therapeutic proteins poses serious problems for patients. Endotoxins can cause fever, respiratory distress syndromes, intravascular coagulation, or endotoxic shock. A number of methods have been devised to remove endotoxins from protein preparations using separation procedures based on molecular mass or charge properties. Most of the methods are limited in their endotoxin removal capacities and lack general applicability. We are describing a biotechnological approach for endotoxin removal. This strategy exploits the observation that endotoxins form micelles that expose negative charges on their surface, leading to preferential binding of endotoxins to cationic surfaces, allowing the separation from their resident protein. Endotoxins exhibit high affinity to stretches of histidines, which are widely used tools to facilitate the purification of recombinant proteins. They bind to nickel ions and are the basis for protein purification from cellular extracts by immobilized metal affinity chromatography. We show that the thrombin-mediated cleavage of two histidine tags from the purified recombinant protein and the adsorption of these histidine tags and their associated endotoxins to a nickel affinity column result in an appreciable depletion of the endotoxins in the purified protein fraction.

  14. Endotoxin inactivation via steam-heat treatment in dilute simethicone emulsions used in biopharmaceutical processes.

    PubMed

    Britt, Keith A; Galvin, Jeffrey; Gammell, Patrick; Nti-Gyabaah, Joseph; Boras, George; Kolwyck, David; Ramirez, José G; Presente, Esther; Naugle, Gregory

    2014-01-01

    Simethicone emulsion is used to regulate foaming in cell culture operations in biopharmaceutical processes. It is also a potential source of endotoxin contamination. The inactivation of endotoxins in dilute simethicone emulsions was assessed as a function of time at different steam temperatures using a Limulus amebocyte lysate kinetic chromogenic technique. Endotoxin inactivation from steam-heat treatment was fit to a four-parameter double exponential decay model, which indicated that endotoxin inactivation was biphasic, consisting of fast and slow regimes. In the fast regime, temperature-related effects were dominant. Transitioning into the slow regime, the observed temperature dependence diminished, and concentration-related effects became increasingly significant. The change in the Gibbs free energy moving through the transition state indicated that a large energy barrier must be overcome for endotoxin inactivation to occur. The corresponding Arrhenius pre-exponential factor was >10(12) s(-1) suggesting that endotoxins in aqueous solution exist as aggregates. The disorder associated with the endotoxin inactivation reaction pathway was assessed via the change in entropy moving through the transition state. This quantity was positive indicating that endotoxin inactivation may result from hydrolysis of individual endotoxin molecules, which perturbs the conformation of endotoxin aggregates, thereby modulating the biological activity observed. Steam-heat treatment decreased endotoxin levels by 1-2 logarithm (log) reduction (LRV), which may be practically relevant depending on incoming raw material endotoxin levels. Antifoam efficiency and cell culture performance were negligibly impacted following steam-heat treatment. The results from this study show that steam-heat treatment is a viable endotoxin control strategy that can be implemented to support large-scale biopharmaceutical manufacturing.

  15. In vivo quantitation of the rat liver's ability to eliminate endotoxin from portal vein blood

    SciTech Connect

    Yamaguchi, Y.; Yamaguchi, K.; Babb, J.L.; Gans, H.

    1982-12-01

    The in vivo uptake of endotoxin by the liver from portal vein blood was assessed during a single passage through the liver. /sup 51/Cr labeled and unlabeled endotoxin were infused in different amounts into the femoral vein of three groups of lead-sensitized rats: a nonoperated, a sham-operated, and a surgically created reversed Eck fistula (REF) group. Whereas in the former two the infused endotoxin encounters the lung as the first filter organ, the liver performs this function in the latter experimental model. The mortality rates observed in control and sham-operated, lead-sensitized rats were found to correlate closely and reproducibly to the degree of endotoxemia. This assay was then applied to determine the amount of endotoxin eliminated by the liver by establishing, in the REF rat, the amounts of endotoxin that escaped hepatic clearance. The capacity of the liver to eliminate endotoxin from portal vein blood during a single passage increases as the portal vein endotoxin level rises; it approaches a maximum, suggesting that endotoxin's interaction with the Kupffer cells conforms to classical saturation kinetics. A Lineweaver-Burk plot prepared from these data indicates that the maximal in vivo capacity of the liver to remove endotoxin from portal vein blood approximates 1.5 micrograms/gm liver/hr. Data obtained with the use of radiolabeled endotoxin corroborate the information obtained with the bioassay technique. Endotoxin eliminated by the Kupffer cells in these quantities is slowly disintegrated; 4 hr after termination of the endotoxin infusion, less than 4% of the radiolabel is found in the urine and none in the bile. These observations indicate that the Kupffer cell's functional capacity to sequester and detoxify endotoxin is extensive and far exceeds the requirements imposed by physiological and most pathological conditions.

  16. An analysis of employee exposure to organic dust at large-scale composting facilities

    NASA Astrophysics Data System (ADS)

    Sykes, P.; Allen, J. A.; Wildsmith, J. D.; Jones, K. P.

    2009-02-01

    The occupational health implications from exposure to dust, endotoxin and 1-3 β Glucan at commercial composting sites are uncertain. This study aims to establish employee exposure levels to inhalable and respirable dust, endotoxin and 1-3 β Glucan during various operational practices in the composting process. Personal samples were collected and the inhalable and respirable dust fractions were determined by gravimetric analysis. Endotoxin concentrations were determined using a Limulus Amebocyte Lysate assay (LAL). 1-3 β Glucan levels were estimated using a specific blocking agent to establish the contribution that these compounds gave to the original endotoxin assay. Employees' exposure to dust was found to be generally lower than the levels stipulated in the Control of Substances Hazardous to Health Regulations (COSHH) 2002 (as amended), (median inhalable fraction 1.08 mg/m3, min 0.25 mg/m3 max 10.80 mg/m3, median respirable fraction 0.05 mg/m3, min 0.02 mg/m3, max 1.49 mg/m3). Determination of the biological component of the dust showed that employees' exposures to endotoxin were elevated (median 31.5 EU/m3, min 2.00 EU/m3, max 1741.78 EU/m3), particularly when waste was agitated (median 175.0 EU/m3, min 2.03 EU/m3, max 1741.78 EU/m3). Eight out of 32 (25%) of the personal exposure data for endotoxin exceeded the 200 EU/m3 temporary legal limit adopted in the Netherlands and thirteen out of 32 (40.6%) exceeded the suggested 50 EU/m3 guidance level suggested to protect workers from respiratory health effects. A significant correlation was observed between employee inhalable dust exposure and personal endotoxin concentration (r = 0.728, p<0.05) and also personal endotoxin exposure and 1-3 β Glucan concentration (r = 0.817, p<0.05). Further work is needed to explore the possibility of using inhalable dust concentration as a predictor for personal endotoxin exposure. The general dust levels stipulated in the COSHH Regulations 2002 (as amended) are inadequate for

  17. Global deposition of airborne dioxin.

    PubMed

    Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

    2013-10-15

    We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others.

  18. Removing Endotoxin from Metallic Biomaterials with Compressed Carbon Dioxide-Based Mixtures

    PubMed Central

    Tarafa, Pedro J.; Williams, Eve; Panvelker, Samir; Zhang, Jian; Matthews, Michael A.

    2010-01-01

    Bacterial endotoxins have strong affinity for metallic biomaterials because of surface energy effects. Conventional depyrogenation methods may not eradicate endotoxins and may compromise biological properties and functionality of metallic instruments and implants. We evaluated the solubilization and removal of E. coli endotoxin from smooth and porous titanium (Ti) surfaces and stainless steel lumens using compressed CO2-based mixtures having water and/or surfactant Ls-54. The CO2/water/Ls-54 ternary mixture in the liquid CO2 region (25 °C and 27.6 MPa) with strong mixing removed endotoxin below detection levels. This suggests that the ternary mixture penetrates and dissolves endotoxins from all the tested substrates. The successful removal of endotoxins from metallic biomaterials with compressed CO2 is a promising cleaning technology for biomaterials and reusable medical devices. PMID:21499532

  19. Removal of endotoxin from protein solutions by phase separation using Triton X-114.

    PubMed

    Aida, Y; Pabst, M J

    1990-09-14

    Endotoxin contamination of protein solutions was reduced by a phase separation technique using the detergent, Triton X-114. Protein solutions containing endotoxin were treated with Triton X-114 on ice. The solution was then warmed to 37 degrees C, whereupon two phases formed. The Triton X-114 phase, containing the endotoxin, was precipitated by centrifugation. The first cycle of phase separation produced a 1000-fold reduction of endotoxin from contaminated preparations of cytochrome c, catalase and albumin. Complete removal of endotoxin could be achieved by further cycles of phase separation. Each cycle of phase separation resulted in only a 2% loss of protein, and could be completed within 15 min. The small amount of detergent (0.018%) that persisted in protein solution could be removed by gel filtration or absorption. Proteins treated by this procedure retained normal functions. This phase separation technique provides a rapid and gentle method for removing endotoxin from protein solutions.

  20. Heat pretreatment eliminates spurious butyrylcholinesterase enhancement of endotoxin levels in the kinetic chromogenic assay.

    PubMed

    Brawner, Andrew; Hinrichs, Steven H; Larson, Marilynn A; Lockridge, Oksana

    2016-04-01

    The kinetic chromogenic endotoxin assay measures the release of p-nitroaniline from the chromogenic peptide substrate Ac-IEAR-pNA. As part of our project to purify large quantities of human butyrylcholinesterase (HuBChE), we evaluated pure HuBChE for endotoxin levels. We found that HuBChE contributed up to 90% of the yellow p-nitroaniline product in a standard endotoxin assay through the catalytic hydrolysis of Ac-IEAR-pNA with a rate constant of 0.016 min(-1) and a Km of 2.9 mM in potassium phosphate buffer pH 7.0 at 24 °C. Thus, endotoxin concentrations for native BChE are artificially high in the kinetic chromogenic assay. Destruction of HuBChE catalytic activity by boiling yields endotoxin concentrations that more accurately reflect the endotoxin concentration in purified HuBChE preparations.

  1. Concentration, physical state, and purity of bacterial endotoxin affect its detoxification by ionizing radiation

    SciTech Connect

    Csako, G.; Tsai, C.M.; Hochstein, H.D.; Elin, R.J.

    1986-11-01

    Increasing concentrations of a highly purified bacterial lipopolysaccharide preparation, the U.S. Reference Standard Endotoxin, were exposed to increasing doses of ionizing radiation from a 60Co source. At identical radiation doses both the structural change and Limulus amebocyte lysate (LAL) reactivity were progressively smaller with increasing concentrations of the lipopolysaccharide in an aqueous medium. Under the experimental conditions used, there was a linear relationship between the endotoxin concentration and radiation dose for the structural changes. In contrast to endotoxin in aqueous medium, endotoxin irradiated in its dry state showed no decrease in LAL reactivity and rabbit pyrogenicity. Endotoxin exposed to radiation in water in the presence of albumin showed a much smaller decrease in LAL and pyrogenic activities than expected. The results show that the concentration, physical state, and purity of endotoxin influence its structural and functional alteration by ionizing radiation.

  2. Airborne data acquisition techniques

    SciTech Connect

    Arro, A.A.

    1980-01-01

    The introduction of standards on acceptable procedures for assessing building heat loss has created a dilemma for the contractor performing airborne thermographic surveys. These standards impose specifications on instrumentation, data acquisition, recording, interpretation, and presentation. Under the standard, the contractor has both the obligation of compliance and the requirement of offering his services at a reasonable price. This paper discusses the various aspects of data acquisition for airborne thermographic surveys and various techniques to reduce the costs of this operation. These techniques include the calculation of flight parameters for economical data acquisition, the selection and use of maps for mission planning, and the use of meteorological forecasts for flight scheduling and the actual execution of the mission. The proper consideration of these factors will result in a cost effective data acquisition and will place the contractor in a very competitive position in offering airborne thermographic survey services.

  3. Bioactive and total endotoxins in atmospheric aerosols in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Cheng, Jessica Y. W.; Hui, Esther L. C.; Lau, Arthur P. S.

    2012-02-01

    Endotoxin, a toxic and pyrogenic substance in gram-negative bacteria in atmospheric aerosols was measured over a period of one year at Nansha, Guangzhou and Hong Kong in the Pearl River Delta region, China. Atmospheric aerosols were collected by high-volume samplers. The bioactive endotoxin levels in the samples were determined using the Limulus Amebocyte Lysate (LAL) assay after extraction with pyrogen-free water while the total endotoxin levels were measured by quantifying the biomarker, 3-hydroxy fatty acids (3-OHFAs) with GC-MS. Results showed that there was no significant difference (0.19 < p < 0.81) in the bioactive endotoxin level in PM 10 among sites (average concentrations ranged from 0.34 to 0.39 EU m -3). However, Hong Kong showed a significantly lower ( p < 0.05) total endotoxin level in PM 10 (average of 17.4 ng m -3) compared with Nansha's 29.4 ng m -3 and Guangzhou's 32.7 ng m -3. The bioactive endotoxins were found to be associated with the coarse mode (PM 2.5-10) of the particulates of natural origins while the total endotoxins were associated more with the fine mode (PM 2.5) of the particulates of anthropogenic origins. When normalized with particulate mass, the endotoxin loading is much higher in summer as a result of the increased growth of the bacteria when climatic conditions are favorable. The chemically determined total endotoxins were 3-4 orders of magnitude higher than the bioactive endotoxins quantified using the LAL assay. Correlation analyses between the bioactive endotoxins and 3-OHFAs with different carbon length were analyzed. Results showed that the correlations detected vary among sites and particulate sizes. Although no generalization between the total and bioactive endotoxins can be drawn from the study, the levels reported in this study suggests that the discrepancies between the two measurement approaches, and the bioactive potential of 3-OHFAs with individual carbon chains deserve further investigation.

  4. Treatment Characteristics of Polysaccharides and Endotoxin Using Oxygen Plasma Produced by RF Discharge

    NASA Astrophysics Data System (ADS)

    Kitazaki, Satoshi; Hayashi, Nobuya; Goto, Masaaki

    2010-10-01

    Treatment of polysaccharides and endotoxin were attempted using oxygen plasma produced by RF discharge. Oxygen radicals observed by optical light emission spectra are factors of decomposition of polysaccharides and endotoxin. Fourier transform infrared spectra indicate that most of chemical bonds in the polysaccharides are dissociated after irradiation of the oxygen plasma. Also, the decomposition rate of endotoxin was approximately 90% after irradiation of the oxygen plasma for 180 min.

  5. Treatment Characteristics of Polysaccharides and Endotoxin Using Oxygen Plasma Produced by RF Discharge

    SciTech Connect

    Kitazaki, Satoshi; Hayashi, Nobuya; Goto, Masaaki

    2010-10-13

    Treatment of polysaccharides and endotoxin were attempted using oxygen plasma produced by RF discharge. Oxygen radicals observed by optical light emission spectra are factors of decomposition of polysaccharides and endotoxin. Fourier transform infrared spectra indicate that most of chemical bonds in the polysaccharides are dissociated after irradiation of the oxygen plasma. Also, the decomposition rate of endotoxin was approximately 90% after irradiation of the oxygen plasma for 180 min.

  6. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Specifications and preliminary design of an Airborne Oceanographic Lidar (AOL) system, which is to be constructed for installation and used on a NASA Wallops Flight Center (WFC) C-54 research aircraft, are reported. The AOL system is to provide an airborne facility for use by various government agencies to demonstrate the utility and practicality of hardware of this type in the wide area collection of oceanographic data on an operational basis. System measurement and performance requirements are presented, followed by a description of the conceptual system approach and the considerations attendant to its development. System performance calculations are addressed, and the system specifications and preliminary design are presented and discussed.

  7. Airborne rain mapping radar

    NASA Technical Reports Server (NTRS)

    Wilson, W. J.; Parks, G. S.; Li, F. K.; Im, K. E.; Howard, R. J.

    1988-01-01

    An airborne scanning radar system for remote rain mapping is described. The airborne rain mapping radar is composed of two radar frequency channels at 13.8 and 24.1 GHz. The radar is proposed to scan its antenna beam over + or - 20 deg from the antenna boresight; have a swath width of 7 km; a horizontal spatial resolution at nadir of about 500 m; and a range resolution of 120 m. The radar is designed to be applicable for retrieving rainfall rates from 0.1-60 mm/hr at the earth's surface, and for measuring linear polarization signatures and raindrop's fall velocity.

  8. Endotoxin suppresses surfactant synthesis in cultured rat lung cells

    SciTech Connect

    Li, J.J.; Sanders, R.L.; McAdam, K.P.; Gelfand, J.A.; Burke, J.F.

    1989-02-01

    Pulmonary complications secondary to postburn sepsis are a major cause of death in burned patients. Using an in vitro organotypic culture system, we examined the effect of E. coli endotoxin (LPS) on lung cell surfactant synthesis. Our results showed that E. coli endotoxin (1.0, 2.5, 10 micrograms LPS/ml) was capable of suppressing the incorporation of /sup 3/H-choline into de novo synthesized surfactant, lamellar bodies (LB), and common myelin figures (CMF) at 50%, 68%, and 64%, respectively. In a similar study, we were able to show that LPS also inhibited /sup 3/H-palmitate incorporation by cultured lung cells. LPS-induced suppression of surfactant synthesis was reversed by hydrocortisone. Our results suggest that LPS may play a significant role in reducing surfactant synthesis by rat lung cells, and thus contribute to the pathogenesis of sepsis-related respiratory distress syndrome (RDS) in burn injury.

  9. NASA Airborne Lidar July 1991

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar July 1991 Data from the 1991 NASA Langley Airborne Lidar flights following the eruption of Pinatubo in July ... and Osborn [1992a, 1992b]. Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  10. NASA Airborne Lidar May 1992

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar May 1992 An airborne Nd:YAG (532 nm) lidar was operated by the NASA Langley Research Center about a year following the June 1991 eruption of ... Osborn [1992a, 1992b].  Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  11. Masking of endotoxin in surfactant samples: Effects on Limulus-based detection systems.

    PubMed

    Reich, Johannes; Lang, Pierre; Grallert, Holger; Motschmann, Hubert

    2016-09-01

    Over the last few decades Limulus Amebocyte Lysate (LAL) has been the most sensitive method for the detection of endotoxins (Lipopolysaccharides) and is well accepted in a broad field of applications. Recently, Low Endotoxin Recovery (LER) in biopharmaceutical drug products has been noticed, whereby the detection of potential endotoxin contaminations is not ensured. Notably, most of these drug products contain surfactants, which can have crucial effects on the detectability of endotoxin. In order to analyze the driving forces of LER, endotoxin detection in samples containing nonionic surfactants in various buffer systems was investigated. The results show that the process of LER is kinetically controlled and temperature-dependent. Furthermore, only the simultaneous presence of nonionic surfactants and components capable of forming metal complexes resulted in LER. In addition, capacity experiments show that even hazardous amounts of endotoxin can remain undetectable within such formulation compositions. In conclusion, the LER phenomenon is caused by endotoxin masking and not by test interference. In this process, the supramolecular structure of endotoxin is altered and exhibits only a limited susceptibility in binding to the Factor C of Limulus-based detection systems. We propose a two-step mechanism of endotoxin masking by complex forming agents and nonionic surfactants. PMID:27464990

  12. Human very low density lipoproteins and chylomicrons can protect against endotoxin-induced death in mice.

    PubMed Central

    Harris, H W; Grunfeld, C; Feingold, K R; Rapp, J H

    1990-01-01

    Endotoxemia stimulates many physiologic responses including disturbances in lipid metabolism. We hypothesized that this lipemia may be part of a defensive mechanism by which the body combats the toxic effects of circulating endotoxin. We tested the effects of mixtures of endotoxin, lipoproteins, and lipoprotein-free plasma and determined the ability of varying concentrations of human very low density lipoproteins (VLDL) and chylomicrons, as well as low density lipoproteins (LDL) and high density lipoproteins (HDL), and of the synthetic lipid emulsion SOYACAL to prevent endotoxin-induced death in mice. This study demonstrates that the triglyceride-rich VLDL and chylomicrons, as well as cholesterol-rich LDL and HDL, and cholesterol-free SOYACAL can protect against endotoxin-induced death. Protection required small amounts of lipoprotein-free plasma, and depended on the incubation time and the concentration of lipoprotein lipid. Despite stringent techniques to prevent exogenous endotoxin contamination eight of ten duplicate VLDL preparations contained endotoxin (5,755 +/- 3,514 ng endotoxin/mg triglyceride, mean +/- SEM) making the isolation of endotoxin-free VLDL difficult. In contrast, simultaneous preparations of LDL and HDL were relatively free of endotoxin contamination (3 +/- 3 and 320 +/- 319 ng/mg total cholesterol, respectively), suggesting that the contamination of VLDL occurs in vivo and not during the isolation procedure. These observations suggest a possible role for increased triglyceride-rich lipoproteins in the host's defense against endotoxemia and infection. Images PMID:2394827

  13. Detection of bacterial endotoxin in drinking tap and bottled water in Kuwait.

    PubMed

    Abdulraheem, Abdulkareem; Mustafa, Seham; Al-Saffar, Nabeel; Shahjahan, Muhammed

    2012-12-01

    This study was carried out to measure and compare the concentration of bacterial endotoxin in a variety of samples from drinking tap and bottled water available in Kuwait by using the Limulus Amoebocyte lysate test. A total of 29 samples were tested. Samples were collected from a variety of locations throughout the six governorates of Kuwait and 23 brands of local and imported bottled water samples were collected from the local market. The concentration of bacterial endotoxin was measured by using the standard Limulus Amoebocyte lysate test, gel clot method. This study showed that measured endotoxin concentrations in tap drinking water varied from 2.4 to 33.8 EU/ml with the average endotoxin concentration of 14.2 EU/ml. While the results of endotoxin concentrations in the bottled water were <0.03 to 20.1 EU/ml with an average of 1.96 EU/ml. The average concentration of endotoxin in bottled water is 13.5 % of the average concentration of endotoxin in tap drinking water. This experimental investigation has proved that drinking bottled water has less endotoxin as compared to tap water in Kuwait. It is also demonstrated that the endotoxin concentration did not exceed the acceptable level in drinking tap water.

  14. Protection against hyperoxia by serum from