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| Registros recuperados: 40 | |
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| Dungan, R.S.; Leytem, A.B.. |
| Endotoxins are derived from gram-negative bacteria and are a potential respiratory health risk for animals and humans. To determine the potential for endotoxin transport from a large open-lot dairy, total airborne endotoxin concentrations were determined at an upwind location (background) and five downwind locations on three separate days. The downwind locations were situated at of the edge of the lot, 200 and 1390 m downwind from the lot, and downwind from a manure composting area and wastewater holding pond. When the wind was predominantly from the west, the average endotoxin concentration at the upwind location was 24 endotoxin units (EU) m?3, whereas at the edge of the lot on the downwind side it was 259 EU m?3. At 200 and 1390 m downwind... |
| Tipo: Article |
Palavras-chave: Manure. |
| Ano: 2009 |
URL: http://eprints.nwisrl.ars.usda.gov/1330/1/1307.pdf |
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| Dungan, R.S.. |
| 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 plant. Filter extracts were then diluted to examine the effect of interfering substances on the kinetic Limulus amebocyte lysate (LAL) assay. In most cases, the overall endotoxin concentration was shown to decrease with increasing dilution up to 1,000-fold, suggesting the presence of enhancing substances in the filter extracts. This dilution dependent effect was most prominent in the inhalable endotoxin samples, while total endotoxin samples displayed little... |
| Tipo: Article |
Palavras-chave: Air Emissions; Endotoxins. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1410/1/1380.pdf |
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| Dungan, R.S.; Leytem, A.B.. |
| Endotoxins are derived from gram-negative bacteria and are a potent inducer of inflammatory reactions in the respiratory tract when inhaled. To assess daily fluctuations of airborne endotoxin and their potential for transport from dairies, endotoxin concentrations were monitored over an 8-h period at upwind (background) and downwind (5 m from edge of dairy) locations on three separate days at two dairies. The dairies consisted of an open-lot or an open-freestall production system, both of which were stocked with 10,000 milking cows. Upwind concentrations were stable throughout the sampling period, averaging between 1.2 and 36.8 endotoxin units (EU) m-3, whereas downwind concentration averages ranged from 179 to 989 EU-3. Downwind endotoxin concentrations... |
| Tipo: Article |
Palavras-chave: Air Emissions; Endotoxins; Manure Management. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1411/1/1381.pdf |
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| Miguel, Roberto E.; Ippolito, J.A.; Leytem, A.B.; Porta A, Atilio; Noriega, Roxana B. Banda; Dungan, R.S.. |
| Waste molding and core sands from the foundry industry have been successfully used around the world as byproducts in geotechnical and agricultural applications. Although waste foundry sands (WFSs) are generally not considered hazardous in nature, relevant data are not available in Argentina. This study aimed to quantify metals in waste molding and core sands from foundries using a variety of metal-binder combinations. Metal concentrations in WFSs were compared to those in virgin silica sands (VSSs), surface soil and soil guidance levels according to hazardous waste law 24.051 from the Argentinean Secretariat of Environment and Sustainable Development. A total analysis for Ag, Al, Ba, Be, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Te, Tl, V, and Zn... |
| Tipo: Article |
Palavras-chave: Foundry sand. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1462/1/1427.pdf |
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| Franklin, A.M.; Aga, D.S.; Cytryn, Eddie; Durso, L.M.; Mclain, J.E.; Pruden, Amy; Roberts, M.C.; Rothrock, Jr, M.J.; Snow, D.D.; Watson, J.E.; Dungan, R.S.. |
| The presence of antibiotic drug residues, antibiotic resistant bacteria, and antibiotic resistance genes in agroecosystems has become a significant area of research in recent years, and is a growing public health concern. While antibiotics are utilized for human medicine and agricultural practices, the majority of antibiotic use occurs in food animals where these drugs have historically been used for growth promotion, in addition to prevention and treatment of disease. The widespread use of antibiotics combined with the application of human and animal wastes to agricultural fields introduces antibiotic-related contamination into the environment. While overt toxicity in organisms directly exposed to antibiotic in agroecosystems is generally not an issue due... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal; Runoff; Manure. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1614/1/1571.pdf |
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| Dungan, R.S.; Leytem, A.B.; Verwey, S.; Bjorneberg, D.L.. |
| Increased bioaerosol loadings in downwind plumes from concentrated animal feeding operations (CAFOs) may increase the risk for allergy and infection in humans. In this study we monitored airborne concentrations of culturable bacteria and fungi at upwind (background) and downwind sites at a 10,000 milking cow dairy over the course of a year. The average bacterial concentrations at the upwind site were 8,400 colony forming units (CFU)/cubic meter and increased to 990,000 CFU/cubic meter at the downwind edge of the cattle pens, decreasing to 63,000 CFU/cubic meter 200 m farther downwind. At the same sites, the average fungal concentrations were 515, 945, and 1010 CFU/cubic meter, respectively. Significant correlations between the ambient weather data and... |
| Tipo: Article |
Palavras-chave: Manure Management; Air Emissions; Bioaerosols. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1403/1/1373.pdf |
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| Leytem, A.B.; Dungan, R.S.; Bjorneberg, D.L.. |
| The volatilization of NH3 from dairy production facilities is not only a loss of valuable N, but also an air quality concern because NH3 plays a role in the formation of airborne particulate matter, which can be a health hazard. The ambient NH3 concentrations over several seasons at 3 locations (open lots, compost yard, lagoon) throughout a large openlot dairy were determined, as well as the spatial distribution of NH3 over the open-lot area. There was a significant main effect of location (P < 0.0001), which followed the trend of lot > lagoon = compost > background, with averages of 0.58, 0.33, 0.30, and 0.04 mg NH3/m3, respectively. The effect of weather and lot conditions on the spatial distribution of NH3 across the lots was evident, with... |
| Tipo: Article |
Palavras-chave: Manure; Soil; Animal. |
| Ano: 2009 |
URL: http://eprints.nwisrl.ars.usda.gov/1367/1/1344.pdf |
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| Dayton, E.A.; Whitacre, S.D.; Dungan, R.S.; Basta, N.T.. |
| Abstract As of 2007, of the 2,000 United States foundries, 93% produce ferrous or aluminum castings, generating 9.4 million tons of non-hazardous spent foundry sand (SFS) annually. Only 28% of the SFS is beneficially used. The U.S. EPA Resource Conservation Challenge identifies SFS as a priority material for beneficial use, with soil blending as a potential reuse option. The objectives of this work were to measure: (1) select chemical and physical properties important to soil quality and function and (2) total and soluble elemental content of 39 SFSs, in order to evaluate SFS suitability as a component in manufactured soils. Total elemental concentration of the SFS was lower than natural background soil levels for most elements analyzed, suggesting limited... |
| Tipo: Article |
Palavras-chave: Soil. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1359/1/1336.pdf |
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| Dungan, R.S.; Leytem, A.B.; Bjorneberg, D.L.. |
| Confined animal production systems produce elevated bioaerosol concentrations, which are a potential respiratory health risk to individuals on site and downwind. In this study, airborne endotoxin and microorganisms were collected during the spring, summer, and fall at a large open-freestall dairy in southern Idaho. Compared to the background ambient atmosphere, both endotoxin and culturable heterotrophic bacteria concentrations were up to several-hundred fold greater 50 m downwind from the facility, then decreased to near background concentrations at 200 m. However, downwind fungi concentrations were not elevated above background concentrations. At 50 m downwind, the average inhalable endotoxin concentration ranged from 4.6 to 4243 endotoxin units/cubic... |
| Tipo: Article |
Palavras-chave: Air Emissions; Manure. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1437/1/1404.pdf |
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| Dungan, R.S.; Leytem, A.B.. |
| Purple sulfur bacteria (PSB) in livestock wastewaters use reduced sulfur compounds and simple volatile organics as growth factors. As a result, the presence of PSB in manure storage ponds or lagoons is often associated with reduced odors. In this study, our objectives were to use molecular- and culture-based techniques to evaluate the occurrence of PSB in eight dairy wastewater ponds and identify physiochemical properties that might cause blooms to occur. Community DNA was extracted from composited wastewater samples, then the PufM gene and a conservative sequence for Chromatiaceae were amplified. Analysis of the 16S rRNA genes from denaturing gradient gel electrophoresis (DGGE) bands indicated that all of the dairy wastewater ponds contained sequences... |
| Tipo: Article |
Palavras-chave: Air Emissions. |
| Ano: 2015 |
URL: http://eprints.nwisrl.ars.usda.gov/1604/1/1562.pdf |
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| Dungan, R.S.; Kim, Jong-Shik; Makama, Mfundi; Petito, Janine; Park, Nyun-Ho; Cohan, F.M.. |
| The objective of this study was to phylogenetically analyze microorganisms from the domains Bacteria and Archaea in hypersaline sediment from Death Valley National Park. Using domain-specific primers, a region of the 16S rRNA gene was amplified using PCR, and the product was subsequently used to create a clone library. A total of 243 bacterial clones, 99 archaeal clones, and 209 bacterial isolates were examined. The 243 clones from Bacteria were affiliated with the following groups: the Bacilli (59 clones) and Clostridia (1) of the Firmicutes, Bacteroidetes (90), Proteobacteria (27), Cyanobacteria (18), Gemmatimonadetes (41), candidate division OP1 (5), Actinobacteria (1), and the Deinococcus-Thermus division (1). Within the class Bacilli, 46 of 59... |
| Tipo: Article |
Palavras-chave: Soil. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1453/1/1418.pdf |
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| Niu, M; Appuhamy, J.A.D.R.N; Leytem, A.B.; Dungan, R.S.; Kebreab, Ermias. |
| The study aimed to examine, simultaneously, the effects of changing dietary forage and crude protein (CP) contents on methane (CH4) emissions and nitrogen (N) excretion from lactating dairy cows. Twelve post-peak lactating Holstein cows were randomly assigned to 4 treatments from a 2×2 factorial arrangement of two dietary forage levels [37.4% (LF) vs. 53.3% (HF) of DM] and two dietary CP levels [15.2% (LP) vs. 18.5% (HP) of DM] in a 4×4 Latin square design with four 18 d periods. Alfalfa hay was the sole source of dietary forage. Cows were fed and milked twice daily. During the first 14 d, cows were housed in a free-stall barn, where enteric CH4 emissions were measured using the GreenFeed system from d 8 to 14 in each period. Cows were then moved to... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal Production; Feed preference; Animal. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1618/1/1575.pdf |
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| Dungan, R.S.; Bjorneberg, D.L.; Leytem, A.B.. |
| In this study we conducted simulated spray irrigation events of dairy wastewater to assess the impact of pressure and sprinkler type upon post-sprinkler culturable microorganism concentrations. Dairy wastewater was sampled before and after it was pumped through sprinklers typically used on center pivot irrigation systems. Three different sprinklers types were used at three different operating pressures to give a range of water drop sizes. The microorganisms quantified in this study were total coliforms, Escherichia coli, Clostridium perfringens, heterotrophic bacteria, and coliphage. In most cases the pre- and post-sprinkler concentrations were determined to be statistically similar, suggesting that culturable viability was not affected when wastewater... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Manure. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1444/1/1409.pdf |
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| Leytem, A.B.; Dungan, R.S.; Bjorneberg, D.L.; Koehn, A.C.. |
| Concentrated animal feeding operations emit trace gases such as ammonia (NH3), methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) to the atmosphere. The implementation of air quality regulations in livestock-producing states increases the need for accurate on-farm determination of emission rates. The objective of this study was to determine the emission rates of NH3, CH4, CO2, and N2O from three source areas (open-lots, lagoon, compost) on a commercial dairy located in southern Idaho. Average emissions per cow per day from the open-lots were 0.12 kg NH3, 0.49 kg CH4, 26.9 kg CO2, and 0.01 kg N2O. Average emissions from the lagoon (g per m square per day) were 1.5 g NH3, 132 g CH4, 391 g CO2, and 0.36 g N2O. Average emissions from the compost... |
| Tipo: Article |
Palavras-chave: Manure; Animal; Chemistry. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1392/3/1365.pdf |
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| Dungan, R.S.. |
| In the western United States where dairy wastewaters are commonly land applied, there are concerns over individuals being exposed to airborne pathogens. In response, a quantitative microbial risk assessment (QMRA) was performed to estimate infectious risks after inhalation exposure of pathogens aerosolized during center pivot irrigation of diluted dairy wastewaters. The dispersion of pathogens (Campylobacter jejuni, Escherichia coli O157:H7, non-O157 E. coli, Listeria monocytogenes, and Salmonella spp.) was modeled using the atmospheric dispersion model, AERMOD. Pathogen concentrations at downwind receptors were used to calculate infectious risks during one-time (1, 8, and 24 h) and multi-day (7 d at 1 h/d) exposure events using a Beta-Poisson... |
| Tipo: Article |
Palavras-chave: Microbial Transport; Center pivot. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1538/1/1495.pdf |
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| King, B.A.; Dungan, R.S.; Bjorneberg, D.L.. |
| Wind drift and evaporation losses (WDELs) are an often discussed topic in regards to center pivot sprinkler irrigation efficiency. Opinions on the magnitude of WDELs vary widely, in part due to the wide variation in WDEL values published in the literature. The magnitude of WDELs reported in the literature range from 2 to 45%. The common technique employed to measure WDEL is to use catch cans and compare the measured volume of catch with the volume of water applied based on sprinkler nozzle size, operating pressure and spacing with the difference being WDEL. The inaccuracies of catch cans resulting from wind effects on catch efficiency and evaporation of water from the catch can prior to measurement have led to the wide range in WDEL reported in the... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Center pivot. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1470/1/1435.pdf |
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| Dungan, R.S.. |
| Airborne microorganisms and microbial byproducts from intensive livestock and manure management systems are a potential health risk to workers and individuals in nearby communities. This report presents information on zoonotic pathogens in animal wastes and the generation, fate, and transport of bioaerosols associated with animal feeding operations and land applied manures. Though many bioaerosol studies have been conducted at animal production facilities, few have investigated the transport of bioaerosols during the land application of animal manures. As communities in rural areas converge with land application sites, concerns over bioaerosol exposure will certainly increase. While most studies at animal operations and wastewater spray irrigation sites... |
| Tipo: Article |
Palavras-chave: Manure Management; Manure. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1405/1/1375.pdf |
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| Leytem, A.B.; Dungan, R.S.; Bjorneberg, D.L.; Koehn, A.C.. |
| Concentrated dairy operations emit trace gases such as ammonia (NH3), methane (CH4), and nitrous oxide (N2O) to the atmosphere. The implementation of air quality regulations in livestock-producing states increases the need for accurate on-farm determination of emission rates. The objective of this study was to determine the emission rates of NH3, CH4, and N2O from the open-freestall and wastewater pond source areas on a commercial dairy located in southern Idaho. Gas concentrations and wind statistics were measured each month and used with an inverse dispersion model to calculate emission rates. Average emissions per cow per day from the open-freestall source area were 0.10 kg NH3 and 0.47 kg CH4. Average emissions from the wastewater ponds (g m-2 d-1)... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal Production; Manure Management. |
| Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1501/1/1464.pdf |
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| Registros recuperados: 40 | |
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