|
|
|
| Registros recuperados: 40 | |
|
|
| Lou, Lifang; Ashworth, Daniel; Dungan, R.S.; Xuan, Richeng; Yates, S.R.. |
| For fumigants, information on transport and fate, as well as pest control, is needed to develop management practices with the fewest human and environmental health risks while offering sufficient pest control efficacy. For this purpose, a 2-D soil chamber (60 cm wide, 60 cm long, and 6 cm thick) with a surface-mounted flux chamber was designed to determine volatilization, spatial and temporal distribution of soil gas-phase concentration, degradation and organism survivability after methyl iodide (MeI) fumigation. Three types of pests (barnyardgrass seed [Echinochloa crus-galli], citrus nematode [Tylenchulus semipenetrans], and fungi [Fusarium oxysporum]) were used to give a broad spectrum of pest control information. After MeI fumigation at a rate of 56.43... |
| Tipo: Article |
Palavras-chave: Soil. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1395/1/1369.pdf |
| |
|
|
| Miguel, Roberto E.; Ippolito, J.A.; Noriega, Roxana B; Dungan, R.S.. |
| As part of the casting process, foundries create sand molds and cores to produce ferrous and non-ferrous metal castings. After the process, a portion of the sand is discarded and becomes waste foundry sand (WFS). The aim of this study was to quantify metals (i.e. Ag, Ba, Cd, Cr, Cu, Ni, Pb, and Zn) in leaching extracts from a variety of waste molding and core sands from ferrous and non-ferrous foundries using the Extraction Procedure, Toxicity Characteristic Leaching Procedure, and ASTM water extraction procedure. The WFS metal extract concentrations were compared to those found in virgin silica sands and Argentinean and U.S. hazardous waste laws to determine if the WFSs met toxicity limits. The majority of the WFS extracts analyzed, regardless of metal... |
| Tipo: Article |
Palavras-chave: Amendments; Soil quality; Water quality. |
| Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1479/1/1444.pdf |
| |
|
| |
|
|
| Carnin, R.L.P; Folgueras, M.V.; Luvizao, R.R.; Correia, S.L.; da Cunha, C.J.; Dungan, R.S.. |
| A fresh green sand, spent green sand, and a weathered spent green sand from a landfill were analyzed using diffractometry, electron microscopy, granulometry, spectrometry, and thermogravimetry. Our objective was to understand how the physicochemical properties of the green sands change from their original form after being subjected to the casting process, then after weathering at the landfill. A quantitative phase composition model was also postulated for each material based on thermogravimetric results and it was found to be the most reliable and informative quantitative data for this type of residue. The weathered sample, that remained in a landfill for two years, was found to be composed of almost pure sand. Because of the weathering process, it may... |
| Tipo: Article |
Palavras-chave: Soil. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1458/1/1423.pdf |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Dungan, R.S.; Klein, Marcus; Leytem, A.B.. |
| Zoonotic pathogens in land-applied dairy wastewaters are a potential health risk. The abundance and occurrence of 10 pathogens and 3 fecal indicators was determined by quantitative real-time PCR (qPCR) in 30 dairy wastewaters from southern Idaho. Samples tested positive for Campylobacter jejuni, stx1- and eaeA-positive Escherichia coli, Listeria monocytogenes, Mycobacterium avium, and Salmonella enterica, with mean recoveries ranging from 1,000 to 10,000 genome copies per mL of wastewater. The most dominant organisms were C. jejuni and M. avium, being detected in up to 21 and 29 of 30 wastewater ponds, respectively. The qPCR detection limits for the putative pathogens in the wastewaters ranged from 16 cells mL for M. avium to 1,689 oocysts mL for... |
| Tipo: Article |
Palavras-chave: Chemistry; Manure. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1473/1/1438.pdf |
| |
|
|
| Dungan, R.S.. |
| Animal manures are known to harbor a variety of zoonotic pathogens, which are suspected of being transported off-site as aerosols from confined feeding operations. In this study, aerosols were collected using a high-volume sampler downwind from a 10,000 cow open-freestall dairy and nearby fields being sprinkler irrigated with wastewater. DNA extracts were prepared from the aerosol samples, then a region of the16S ribosomal RNA gene was sequenced for bacterial identification and phylogenetic classification. At the dairy and irrigation sites, Proteobacteria was the most abundant phylum, representing 78% and 69% of all sequences, respectively, while Actinobacteria, Bacteroidetes and Firmicutes represented only 10% or less of the sequences. Of the 191... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Manure. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1445/1/1410.pdf |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Dungan, R.S.; Leytem, A.B.. |
| The generation of airborne microorganisms from concentrated animal-feeding operations (CAFOs) is a concern from a human and animal health perspective. To better understand the airborne microorganisms found in these environments, a number of collection and analytical techniques have been utilized and will be discussed in this review. The most commonly used bioaerosol collection method is the liquid impingement format, which is suitable with a number of culture-based and non-culture molecularbased approaches, such as polymerase chain reaction. However, the vast majority of airborne microorganism studies conducted at CAFOs utilize culture-based analyses. Because of the limitations often associated with culturebased analyses, we focused our... |
| Tipo: Article |
Palavras-chave: Manure; Animal. |
| Ano: 2009 |
URL: http://eprints.nwisrl.ars.usda.gov/1337/1/1314.pdf |
| |
|
|
| Leytem, A.B.; Dungan, R.S.; Kleinman, P.J.. |
| The sustainability of modern manure management is far from certain, with many demonstrating significant limitations from the stand point of efficient use of manure resources and protection of environmental quality and human health. As demonstrated through this review, for manure management to be sustainable, a broad array of issues must be considered and addressed, all in the context of highly competitive modern livestock production systems that largely seek to minimize costs to the consumer. In the past decade there have been major innovations in the areas of land application, manure treatment and processing and in the science of understanding the impact of manure management. As a result, major opportunities exist to improve the components of manure... |
| Tipo: Book Section |
Palavras-chave: Application guidelines; Chemistry; Nutrient losses; Soil quality. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1589/3/1545.pdf |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Dungan, R.S.; Leytem, A.B.. |
| Collection fluids used in liquid-based bioaerosol samplers can influence the viability of microorganisms. In this study we determined the recovery efficiency of vegetative E. coli O157:H7 cells that were spiked into low viscosity evaporating collection fluids during operation of a BioSampler™ for up to 90 min at room temperature. The collection fluids tested were distilled (DI) water, phosphate-buffered saline (PBS) and osmoprotectants consisting of peptone and/or antifoam or betaine at 0.1% (w/w) in DI water. Using DI water, there was a rapid decline in the recovery of culturable E. coli, with only 11, 3, and 0% being recovered after 30, 60, and 90 min, respectively. Recoveries were substantially greater with use of PBS (53, 25, and 16%, respectively) but... |
| Tipo: Article |
Palavras-chave: Air Emissions; Water quality. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1613/1/1570.pdf |
| |
|
|
| Ippolito, J.A.; Stromberger, M.E.; Lentz, R.D.; Dungan, R.S.. |
| The effects of biochar application to calcareous soils are not well documented. In a laboratory incubation study, a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Changes in soil chemistry, water content, microbial respiration, and microbial community structure were monitored over a 12-month period. Increasing biochar application rate increased the water holding capacity of the soil-biochar blend, a trait that could be beneficial under water limited situations. Biochar application also caused an increase in plant-available iron and manganese, soil carbon content, soil respiration rates, bacterial populations, and a decrease in soil nitrate-nitrogen concentration. Biochar rates of 2 and 10% altered the... |
| Tipo: Article |
Palavras-chave: Calcareous soil; Nitrogen; Nutrients. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1532/1/1490.pdf |
| |
|
|
| Miguel, Roberto E.; Dungan, R.S.; Reeves III, J.B.. |
| Foundries around the world discard millions of tonnes of molding and core sand each year even though they can be beneficially used in manufactured soils and geotechnical applications. Despite their usefulness as an aggregate replacement, some environmental authorities are concerned over potential negative impacts associated with residual organic binders in waste foundry sands (WFSs). In this study, chemically bound molding and core sands were obtained from aluminum, bronze and iron foundries that used alkyd urethane, phenolic urethane, Novolac, and natural organic binders. The aim was to use mid-infrared (MIR) spectrometry to assess changes within the molding and core sands during the casting process, with a specific focus on proximity to the casting... |
| Tipo: Article |
Palavras-chave: Foundry sand. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1536/1/1493.pdf |
| |
| Registros recuperados: 40 | |
|
|
|
