Grazing incidence angle based sensing approach integrated with fiber-optic Fourier transform infrared (FO-FTIR) spectroscopy for remote and label-free detection of medical device contaminations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassan, Moinuddin, E-mail: moinuddin.hassan@fda.hhs.gov; Ilev, Ilko

2014-10-15

Contamination of medical devices has become a critical and prevalent public health safety concern since medical devices are being increasingly used in clinical practices for diagnostics, therapeutics and medical implants. The development of effective sensing methods for real-time detection of pathogenic contamination is needed to prevent and reduce the spread of infections to patients and the healthcare community. In this study, a hollow-core fiber-optic Fourier transform infrared spectroscopy methodology employing a grazing incidence angle based sensing approach (FO-FTIR-GIA) was developed for detection of various biochemical contaminants on medical device surfaces. We demonstrated the sensitivity of FO-FTIR-GIA sensing approach for non-contactmore » and label-free detection of contaminants such as lipopolysaccharide from various surface materials relevant to medical device. The proposed sensing system can detect at a minimum loading concentration of approximately 0.7 μg/cm{sup 2}. The FO-FTIR-GIA has the potential for the detection of unwanted pathogen in real time.« less

Surface Cleaning Techniques: Ultra-Trace ICP-MS Sample Preparation and Assay of HDPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Overman, Nicole R.; Hoppe, Eric W.; Addleman, Raymond S.

2013-06-01

The world’s most sensitive radiation detection and assay systems depend upon ultra-low background (ULB) materials to reduce unwanted radiological backgrounds. Herein, we evaluate methods to clean HDPE, a material of interest to ULB systems and the means to provide rapid assay of surface and bulk contamination. ULB level material and ultra-trace level detection of actinide elements is difficult to attain, due to the introduction of contamination from sample preparation equipment such as pipette tips, sample vials, forceps, etc. and airborne particulate. To date, literature available on the cleaning of such polymeric materials and equipment for ULB applications and ultra-trace analysesmore » is limited. For these reasons, a study has been performed to identify an effective way to remove surface contamination from polymers in an effort to provide improved instrumental detection limits. Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) was utilized to assess the effectiveness of a variety of leachate solutions for removal of inorganic uranium and thorium surface contamination from polymers, specifically high density polyethylene (HDPE). HDPE leaching procedures were tested to optimize contaminant removal of thorium and uranium. Calibration curves for thorium and uranium ranged from 15 ppq (fg/mL) to 1 ppt (pg/mL). Detection limits were calculated at 6 ppq for uranium and 7 ppq for thorium. Results showed the most effective leaching reagent to be clean 6 M nitric acid for 72 hour exposures. Contamination levels for uranium and thorium found in the leachate solutions were significant for ultralow level radiation detection applications.« less

Exploring Surface Analysis Techniques for the Detection of Molecular Contaminants on Spacecraft

NASA Technical Reports Server (NTRS)

Rutherford, Gugu N.; Seasly, Elaine; Thornblom, Mark; Baughman, James

2016-01-01

Molecular contamination is a known area of concern for spacecraft. To mitigate this risk, projects involving space flight hardware set requirements in a contamination control plan that establishes an allocation budget for the exposure of non-volatile residues (NVR) onto critical surfaces. The purpose of this work will focus on non-contact surface analysis and in situ monitoring to mitigate molecular contamination on space flight hardware. By using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS) with Raman Spectroscopy, an unlikely contaminant was identified on space flight hardware. Using traditional and surface analysis methods provided the broader view of the contamination sources allowing for best fit solutions to prevent any future exposure.

Stochastic Radiative Transfer Model for Contaminated Rough Surfaces: A Framework for Detection System Design

DTIC Science & Technology

2013-11-01

STOCHASTIC RADIATIVE TRANSFER MODEL FOR CONTAMINATED ROUGH SURFACES: A...of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid ...COVERED (From - To) Jan 2013 - Sep 2013 4. TITLE AND SUBTITLE Stochastic Radiative Transfer Model for Contaminated Rough Surfaces: A Framework for

Surface contamination detection by means of near-infrared stimulation of thermal luminescence

NASA Astrophysics Data System (ADS)

Carrieri, Arthur H.; Roese, Erik S.

2006-02-01

A method for remotely detecting liquid chemical contamination on terrestrial surfaces is presented. Concurrent to irradiation by an absorbing near-infrared beam, the subject soil medium liberates radiance called thermal luminescence (TL) comprising middle-infrared energies (numir) that is scanned interferometrically in beam duration tau. Cyclic states of absorption and emission by the contaminant surrogate are rendered from a sequential differential-spectrum measurement [deltaS(numir,tau)] of the scanned TL. Detection of chemical warfare agent simulant wetting soil is performed in this manner, for example, through pattern recognition of its unique, thermally dynamic, molecular vibration resonance bands on display in the deltaS(numir,tau) metric.

Environmental survey to assess viral contamination of air and surfaces in hospital settings.

PubMed

Carducci, A; Verani, M; Lombardi, R; Casini, B; Privitera, G

2011-03-01

The presence of pathogenic viruses in healthcare settings represents a serious risk for both staff and patients. Direct viral detection in the environment poses significant technical problems and the indirect indicators currently in use suffer from serious limitations. The aim of this study was to monitor surfaces and air in hospital settings to reveal the presence of hepatitis C virus, human adenovirus, norovirus, human rotavirus and torque teno virus by nucleic acid assays, in parallel with measurements of total bacterial count and haemoglobin presence. In total, 114 surface and 62 air samples were collected. Bacterial contamination was very low (<1 cfu/cm(2)) on surfaces, whereas the 'medium' detected value in air was 282 cfu/m(3). Overall, 19 (16.7%) surface samples tested positive for viral nucleic acids: one for norovirus, one for human adenovirus and 17 (14.9%) for torque teno virus (TTV). Only this latter virus was directly detected in 10 air samples (16.1%). Haemoglobin was found on two surfaces. No relationship was found between viral, biochemical or bacterial indicators. The data obtained confirm the difficulty of assessing viral contamination using bacterial indicators. The frequent detection of TTV suggests its possible use as an indicator for general viral contamination of the environment. Copyright © 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Assessment of hyporheic zone, flood-plain, soil-gas, soil, and surface-water contamination at the Old Incinerator Area, Fort Gordon, Georgia, 2009-2010

USGS Publications Warehouse

Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

2011-01-01

The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface-water for contaminants at the Old Incinerator Area at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Total petroleum hydrocarbons were detected above the method detection level in all 13 samplers deployed in the hyporheic zone and flood plain of an unnamed tributary to Spirit Creek. The combined concentrations of benzene, toluene, ethylbenzene, and total xylene were detected at 3 of the 13 samplers. Other organic compounds detected in one sampler included octane and trichloroethylene. In the passive soil-gas survey, 28 of the 60 samplers detected total petroleum hydrocarbons above the method detection level. Additionally, 11 of the 60 samplers detected the combined masses of benzene, toluene, ethylbenzene, and total xylene above the method detection level. Other compounds detected above the method detection level in the passive soil-gas survey included octane, trimethylbenzene, perchlorethylene, and chloroform. Subsequent to the passive soil-gas survey, six areas determined to have relatively high contaminant mass were selected, and soil-gas samplers were deployed, collected, and analyzed for explosives and chemical agents. No explosives or chemical agents were detected above their method detection levels, but those that were detected were above the nondetection level. The same six locations that were sampled for explosives and chemical agents were selected for the collection of soil samples. No metals that exceeded the Regional Screening Levels for Industrial Soils as classified by the U.S. Environmental Protection Agency were detected at any of the six Old Incinerator Area locations. The soil samples also were compared to values from the ambient, uncontaminated (background) levels for soils in South Carolina. Because South Carolina is adjacent to Georgia and the soils in the coastal plain are similar, these comparisons are valid. No similar values are available for Georgia to use for comparison purposes. The only metal detected above the ambient background levels for South Carolina was barium. A surface-water sample collected from a tributary west and north of the Old Incinerator Area was analyzed for volatile organic compounds, semivolatile organic compounds, and inorganic compounds (metals). The only volatile organic and (or) semivolatile organic compound that was detected above the laboratory reporting level was toluene. The compounds 4-isopropyl-1-methylbenzene and isophorone were detected above the nondetection level but below the laboratory reporting level and were estimated. These compounds were detected at levels below the maximum contaminant levels set by the U.S. Environmental Protection Agency National Primary Drinking Water Standard. Iron was the only inorganic compound detected in the surface-water sample that exceeded the maximum contaminant level set by the U.S. Environmental Protection Agency National Secondary Drinking Water Standard. No other inorganic compounds exceeded the maximum contaminant levels for the U.S. Environmental Protection Agency National Primary Drinking Water Standard, National Secondary Drinking Water Standard, or the Georgia In-Stream Water Quality Standard.

Inspection Tools

NASA Astrophysics Data System (ADS)

1989-01-01

A "NASA Tech Briefs" article describing an inspection tool and technique known as Optically Stimulated Electron Emission (OSEE) led to the formation of Photo Acoustic Technology, Inc. (PAT). PAT produces sensors and scanning systems which assure surface cleanliness prior to bonding, coating, painting, etc. The company's OP1000 series realtime pre-processing detection capability assures 100 percent surface quality testing. The technique involves brief exposure of the inspection surface to ultraviolet radiation. The energy interacts with the surface layer, causing free electrons to be emitted from the surface to be picked up by the detector. When contamination is present, it interferes with the electron flow in proportion to the thickness of the contaminant layer enabling measurement by system signal output. OP1000 systems operate in conventional atmospheres on all types of material and detect both organic and inorganic contamination.

Assessment of Surface Water Contamination from Coalbed Methane Fracturing-Derived Volatile Contaminants in Sullivan County, Indiana, USA.

PubMed

Meszaros, Nicholas; Subedi, Bikram; Stamets, Tristan; Shifa, Naima

2017-09-01

There is a growing concern over the contamination of surface water and the associated environmental and public health consequences from the recent proliferation of hydraulic fracturing in the USA. Petroleum hydrocarbon-derived contaminants of concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)] and various dissolved cations and anions were spatially determined in surface waters around 15 coalbed methane fracking wells in Sullivan County, IN, USA. At least one BTEX compound was detected in 69% of sampling sites (n = 13) and 23% of sampling sites were found to be contaminated with all of the BTEX compounds. Toluene was the most common BTEX compound detected across all sampling sites, both upstream and downstream from coalbed methane fracking wells. The average concentration of toluene at a reservoir and its outlet nearby the fracking wells was ~2× higher than other downstream sites. However, one of the upstream sites was found to be contaminated with BTEX at similar concentrations as in a reservoir site nearby the fracking well. Calcium (~60 ppm) and sulfates (~175 ppm) were the dominant cations and anions, respectively, in surface water around the fracking sites. This study represents the first report of BTEX contamination in surface water from coalbed methane hydraulic fracturing wells.

Chemical contamination remote sensing

NASA Technical Reports Server (NTRS)

Carrico, J. P.; Phelps, K. R.; Webb, E. N.; Mackay, R. A.; Murray, E. R.

1986-01-01

A ground mobile laser test bed system was assembled to assess the feasibility of detection of various types of chemical contamination using Differential Scattering (DISC) and Differential Absorption (DIAL) Lidar techniques. Field experiments with the test bed system using chemical simulants were performed. Topographic reflection and range resolved DIAL detection of vapors as well as DISC detection of aerosols and surface contamination were achieved. Review of detection principles, design of the test bed system, and results of the experiments are discussed.

Chromatographic separation and detection of contaminants from whole milk powder using a chitosan-modified silver nanoparticles surface-enhanced Raman scattering device.

PubMed

Li, Dan; Lv, Di Y; Zhu, Qing X; Li, Hao; Chen, Hui; Wu, Mian M; Chai, Yi F; Lu, Feng

2017-06-01

Methods for the on-site analysis of food contaminants are in high demand. Although portable Raman spectroscopy is commonly used to test food on-site, it can be challenge to achieve this goal with rapid detection and inexpensive substrate. In this study, we detected trace food contaminants in samples of whole milk powder using the methods that combined chromatography with surface-enhanced Raman scattering detection (SERS). We developed a simple and efficient technique to fabricate the paper with chitosan-modified silver nanoparticles as a SERS-active substrate. The soaking time of paper and the concentration of chitosan solution were optimized for chromatographic separation and SERS detection. We then studied the separation properties for real applications including complex sample matrices, and detected melamine at 1mg/L, dicyandiamide at 100mg/L and sodium sulfocyanate at 10mg/L in whole milk powder. As such, our methods have great potential for field-based detection of milk contaminants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of Hyporheic Zone, Flood-Plain, Soil-Gas, Soil, and Surface-Water Contamination at the McCoys Creek Chemical Training Area, Fort Gordon, Georgia, 2009-2010

USGS Publications Warehouse

Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

2011-01-01

The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, assessed the hyporheic zone, flood plain, soil gas, soil, and surface water for contaminants at the McCoys Creek Chemical Training Area (MCTA) at Fort Gordon, from October 2009 to September 2010. The assessment included the detection of organic contaminants in the hyporheic zone, flood plain, soil gas, and surface water. In addition, the organic contaminant assessment included the analysis of organic compounds classified as explosives and chemical agents in selected areas. Inorganic contaminants were assessed in soil and surface-water samples. The assessment was conducted to provide environmental contamination data to the U.S. Army at Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Ten passive samplers were deployed in the hyporheic zone and flood plain, and total petroleum hydrocarbons (TPH) and octane were detected above the method detection level in every sampler. Other organic compounds detected above the method detection level in the hyporheic zone and flood-plain samplers were trichloroethylene, and cis- and trans- 1, 2-dichloroethylene. One trip blank detected TPH below the method detection level but above the nondetection level. The concentrations of TPH in the samplers were many times greater than the concentrations detected in the blank; therefore, all other TPH concentrations detected are considered to represent environmental conditions. Seventy-one soil-gas samplers were deployed in a grid pattern across the MCTA. Three trip blanks and three method blanks were used and not deployed, and TPH was detected above the method detection level in two trip blanks and one method blank. Detection of TPH was observed at all 71 samplers, but because TPH was detected in the trip and method blanks, TPH was censored and, therefore, only 7 of the 71 samplers were reported as detecting TPH. In addition, benzene, toluene, ethylbenzene, and total xylene were detected above the method detection level in 22 samplers. Other compounds detected above the method detection level included naphthalene, octane, undecane, tridecane, 1,2,4-trimethylbenzene, trichloroethylene, perchloroethylene, chloroform, and 1,4-dichlorobenzene. Subsequent to the soil-gas survey, five locations with elevated contaminant mass were selected and a passive sampler was deployed at those locations to detect the presence of organic compounds classified as explosives or chemical agents. No explosives or chemical agents were detected above the method detection level, but some compounds were detected below the method detection level but above the nondetection level. Dimethyl disulfide, benzothiazole, chloroacetophenones, and para-chlorophenyl methyl sulfide were all detected below the method detection level but above the nondetection level. The compounds 2,4-dinitrotoluene, and para-chlorophenyl methyl sulfone were detected in samplers but also were detected in trip blanks and are not considered as present in the MCTA. The same five locations that were selected for sampling of explosives and chemical agents were selected for soil sampling. Metal concentrations in composite soil samples collected at five locations from land surface to a depth of 6 inches did not exceed the U.S. Environmental Protection Agency Regional Screening Levels for Industrial Soil. Concentrations in some compounds were higher than the South Carolina Department of Health and Environmental Control background levels for nearby South Carolina, including aluminum, arsenic, barium, beryllium, chromium, copper, iron, lead, manganese, nickel, and potassium. A surface-water sample was collected from McCoys Creek and analyzed for volatile organic compounds, semivolatile organic compounds, and inorganic compounds (metals). No volatile organic compounds and (or) semivolatile organic compounds were detected at levels above the maximum contaminant level of the U.S. Environmental Protection Agency (USEPA) National Primary Drinking Water Standard, and no inorganic compounds exceeded the maximum contaminant level of the USEPA National Primary Drinking Water Standard or the Georgia In-Stream Water-Quality Standard. Iron was the only inorganic compound detected in the surface-water sample (578 micrograms per liter) that exceeded the USEPA National Secondary Drinking Water Standard of 300 micrograms per liter.

Quality of volatile organic compound data from groundwater and surface water for the National Water-Quality Assessment Program, October 1996–December 2008

USGS Publications Warehouse

Bender, David A.; Zogorski, John S.; Mueller, David K.; Rose, Donna L.; Martin, Jeffrey D.; Brenner, Cassandra K.

2011-01-01

This report describes the quality of volatile organic compound (VOC) data collected from October 1996 to December 2008 from groundwater and surface-water sites for the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. The VOC data described were collected for three NAWQA site types: (1) domestic and public-supply wells, (2) monitoring wells, and (3) surface-water sites. Contamination bias, based on the 90-percent upper confidence limit (UCL) for the 90th percentile of concentrations in field blanks, was determined for VOC samples from the three site types. A way to express this bias is that there is 90-percent confidence that this amount of contamination would be exceeded in no more than 10 percent of all samples (including environmental samples) that were collected, processed, shipped, and analyzed in the same manner as the blank samples. This report also describes how important native water rinsing may be in decreasing carryover contamination, which could be affecting field blanks. The VOCs can be classified into four contamination categories on the basis of the 90-percent upper confidence limit (90-percent UCL) concentration distribution in field blanks. Contamination category 1 includes compounds that were not detected in any field blanks. Contamination category 2 includes VOCs that have a 90-percent UCL concentration distribution in field blanks that is about an order of magnitude lower than the concentration distribution of the environmental samples. Contamination category 3 includes VOCs that have a 90-percent UCL concentration distribution in field blanks that is within an order of magnitude of the distribution in environmental samples. Contamination category 4 includes VOCs that have a 90-percent UCL concentration distribution in field blanks that is at least an order of magnitude larger than the concentration distribution of the environmental samples. Fifty-four of the 87 VOCs analyzed in samples from domestic and public-supply wells were not detected in field blanks (contamination category 1), and 33 VOC were detected in field blanks. Ten of the 33 VOCs had a 90-percent UCL concentration distribution in field blanks that was at least an order of magnitude lower than the concentration distribution in environmental samples (contamination category 2). These 10 VOCs may have had some contamination bias associated with the environmental samples, but the potential contamination bias was negligible in comparison to the environmental data; therefore, the field blanks were assumed to be representative of the sources of contamination bias affecting the environmental samples for these 10 VOCs. Seven VOCs had a 90-percent UCL concentration distribution of the field blanks that was within an order of magnitude of the concentration distribution of the environmental samples (contamination category 3). Sixteen VOCs had a 90-percent UCL concentration distribution in the field blanks that was at least an order of magnitude greater than the concentration distribution of the environmental samples (contamination category 4). Field blanks for these 16 VOCs appear to be nonrepresentative of the sources of contamination bias affecting the environmental samples because of the larger concentration distributions (and sometimes higher frequency of detection) in field blanks than in environmental samples. Forty-three of the 87 VOCs analyzed in samples from monitoring wells were not detected in field blanks (contamination category 1), and 44 VOCs were detected in field blanks. Eight of the 44 VOCs had a 90-percent UCL concentration distribution in field blanks that was at least an order of magnitude lower than concentrations in environmental samples (contamination category 2). These eight VOCs may have had some contamination bias associated with the environmental samples, but the potential contamination bias was negligible in comparison to the environmental data; therefore, the field blanks were assumed to be representative. Seven VOCs had a 90-percent UCL concentration distribution in field blanks that was of the same order of magnitude as the concentration distribution of the environmental samples (contamination category 3). Twenty-nine VOCs had a 90-percent UCL concentration distribution in the field blanks that was an order of magnitude greater than the distribution of the environmental samples (contamination category 4). Field blanks for these 29 VOCs appear to be nonrepresentative of the sources of contamination bias to the environmental samples. Fifty-four of the 87 VOCs analyzed in surface-water samples were not detected in field blanks (category 1), and 33 VOC were detected in field blanks. Sixteen of the 33 VOCs had a 90-percent UCL concentration distribution in field blanks that was at least an order of magnitude lower than the concentration distribution in environmental samples (contamination category 2). These 16 VOCs may have had some contamination bias associated with the environmental samples, but the potential contamination bias was negligible in comparison to the environmental data; therefore, the field blanks were assumed to be representative. Ten VOCs had a 90-percent UCL concentration distribution in field blanks that was similar to the concentration distribution of environmental samples (contamination category 3). Seven VOCs had a 90-percent UCL concentration distribution in the field blanks that was greater than the concentration distribution in environmental samples (contamination category 4). Field-blank samples for these seven VOCs appear to be nonrepresentative of the sources of contamination bias to the environmental samples. The relation between the detection of a compound in field blanks and the detection in subsequent environmental samples appears to be minimal. The median minimum percent effectiveness of native water rinsing is about 79 percent for the 19 VOCs detected in more than 5 percent of field blanks from all three site types. The minimum percent effectiveness of native water rinsing (10 percent) was for toluene in surface-water samples, likely because of the large detection frequency of toluene in surface-water samples (about 79 percent) and in the associated field-blank samples (46.5 percent). The VOCs that were not detected in field blanks (contamination category 1) from the three site types can be considered free of contamination bias, and various interpretations for environmental samples, such as VOC detection frequency at multiple assessment levels and comparisons of concentrations to benchmarks, are not limited for these VOCs. A censoring level for making comparisons at different assessment levels among environmental samples could be applied to concentrations of 9 VOCs in samples from domestic and public-supply wells, 16 VOCs in samples from monitoring wells, and 9 VOCs in surface-water samples to account for potential low-level contamination bias associated with these selected VOCs. Bracketing the potential contamination by comparing the detection and concentration statistics with no censoring applied to the potential for contamination bias on the basis of the 90-percent UCL for the 90th-percentile concentrations in field blanks may be useful when comparisons to benchmarks are done in a study. The VOCs that were not detected in field blanks (contamination category 1) from the three site types can be considered free of contamination bias, and various interpretations for environmental samples, such as VOC detection frequency at multiple assessment levels and comparisons of concentrations to benchmarks, are not limited for these VOCs. A censoring level for making comparisons at different assessment levels among environmental samples could be applied to concentrations of 9 VOCs in samples from domestic and public-supply wells, 16 VOCs in samples from monitoring wells, and 9 VOCs in surface-water samples to account for potential low-level contamination bias associated with these selected VOCs. Bracketing the potential contamination by comparing the detection and concentration statistics with no censoring applied to the potential for contamination bias on the basis of the 90-percent UCL for the 90th-percentile concentrations in field blanks may be useful when comparisons to benchmarks are done in a study.

Summary and evaluation of pesticides in field blanks collected for the National Water-Quality Assessment Program, 1992-95

USGS Publications Warehouse

Martin, Jeffrey D.; Gilliom, Robert J.; Schertz, Terry L.

1999-01-01

Field blanks did show evidence of contamination by some pesticides. Most of the pesticides detected in field blanks, however, were detected more frequently and at higher concentrations in environmental water samples. Two criteria were used to evaluate the need to consider contamination in water-quality assessments: (1) a ratio of the frequency of pesticide detection in environmental water samples to the frequency of detection in field blanks of 5.0 or less and (2) a ratio of the median concentration detected in environmental water samples to the maximum concentration detected in field blanks of 2.0 or less. These criteria indicate that contamination, for the majority of the pesticide data collected for the NAWQA Program, probably does not need to be considered in the analysis and interpretation of (1) the frequency of pesticide detection or (2) the median concentration of pesticides detected. Contamination must be considered, however, in detection frequency for cispermethrin, pronamide, p,p' -DDE, pebulate, propargite, ethalfluralin, and triallate in surface water and fenuron, benfluralin, pronamide, cis-permethrin, triallate, chlorpyrifos, trifluralin, propanil, p,p' -DDE, bromacil, dacthal, diazinon, and diuron in ground water. Contamination also must be considered in median concentrations detected for pronamide, p,p' -DDE, propargite, napropamide, and triallate in surface water and benfluralin, cis-permethrin, triallate, chlorpyrifos, trifluralin, p,p' -DDE, dacthal, and diazinon in ground water.

Detection and measurement of surface contamination by multiple antineoplastic drugs using multiplex bead assay

PubMed Central

Smith, Jerome P; Sammons, Deborah L; Robertson, Shirley A; Pretty, Jack; Debord, D Gayle; Connor, Thomas H; Snawder, John

2015-01-01

Objectives Contamination of workplace surfaces by antineoplastic drugs presents an exposure risk for healthcare workers. Traditional instrumental methods to detect contamination such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) are sensitive and accurate but expensive. Since immunochemical methods may be cheaper and faster than instrumental methods, we wanted to explore their use for routine drug residue detection for preventing worker exposure. Methods In this study we examined the feasibility of using fluorescence covalent microbead immunosorbent assay (FCMIA) for simultaneous detection and semi-quantitative measurement of three antineoplastic drugs (5-fluorouracil, paclitaxel, and doxorubicin). The concentration ranges for the assay were 0–1000 ng/ml for 5-fluorouracil, 0–100 ng/ml for paclitaxel, and 0–2 ng/ml for doxorubicin. The surface sampling technique involved wiping a loaded surface with a swab wetted with wash buffer, extracting the swab in storage/blocking buffer, and measuring drugs in the extract using FCMIA. Results There was no significant cross reactivity between these drugs at the ranges studied indicated by a lack of response in the assay to cross analytes. The limit of detection (LOD) for 5-fluorouracil on the surface studied was 0.93 ng/cm2 with a limit of quantitation (LOQ) of 2.8 ng/cm2, the LOD for paclitaxel was 0.57 ng/cm2 with an LOQ of 2.06 ng/cm2, and the LOD for doxorubicin was 0.0036 ng/cm2 with an LOQ of 0.013 ng/cm2. Conclusion The use of FCMIA with a simple sampling technique has potential for low cost simultaneous detection and semi-quantitative measurement of surface contamination from multiple antineoplastic drugs. PMID:25293722

Evaluation of the efficacy of a portable LIBS system for detection of CWA on surfaces.

PubMed

L'Hermite, D; Vors, E; Vercouter, T; Moutiers, G

2016-05-01

Laser-induced breakdown spectroscopy (LIBS) is a laser-based optical technique particularly suited for in situ surface analysis. A portable LIBS instrument was tested to detect surface chemical contamination by chemical warfare agents (CWAs). Test of detection of surface contamination was carried out in a toxlab facility with four CWAs, sarin (GB), lewisite (L1), mustard gas (HD), and VX, which were deposited on different substrates, wood, concrete, military green paint, gloves, and ceramic. The CWAs were detected by means of the detection of atomic markers (As, P, F, Cl, and S). The LIBS instrument can give a direct response in terms of detection thanks to an integrated interface for non-expert users or so called end-users. We have evaluated the capability of automatic detection of the selected CWAs. The sensitivity of our portable LIBS instrument was confirmed for the detection of a CWA at surface concentrations above 15 μg/cm(2). The simultaneous detection of two markers may lead to a decrease of the number of false positive.

Biocontamination and particulate detection system

NASA Technical Reports Server (NTRS)

Jacobs, J. M. (Inventor)

1979-01-01

A method for determining the characteristics and amount of microscopic contaminants lodged on a photographed surface is disclosed. An image enhanced full color photographic negative and print are taken of the contaminated surface. Three black and white prints are developed subsequently from red, green and blue separation filter overlays of the color negative. Both the color and three monochromatic prints are then scanned to extract in digital form a profile of any contaminant possibly existing on the surface. The resulting profiles are electronically analyzed and compared with data already stored relating to known contaminants.

Cleanliness evaluation of rough surfaces with diffuse IR reflectance

NASA Technical Reports Server (NTRS)

Pearson, L. H.

1995-01-01

Contamination on bonding surfaces has been determined to be a primary cause for degraded bond strength in certain solid rocket motor bondlines. Hydrocarbon and silicone based organic contaminants that are airborne or directly introduced to a surface are a significant source of contamination. Diffuse infrared (IR) reflectance has historically been used as an effective technique for detection of organic contaminants, however, common laboratory methods involving the use of a Fourier transform IR spectrometer (FTIR) are impractical for inspecting the large bonding surface areas found on solid rocket motors. Optical methods involving the use of acousto-optic tunable filters and fixed bandpass optical filters are recommended for increased data acquisition speed. Testing and signal analysis methods are presented which provide for simultaneous measurement of contamination concentration and roughness level on rough metal surfaces contaminated with hydrocarbons.

Molecular-level removal of proteinaceous contamination from model surfaces and biomedical device materials by air plasma treatment.

PubMed

Banerjee, K K; Kumar, S; Bremmell, K E; Griesser, H J

2010-11-01

Established methods for cleaning and sterilising biomedical devices may achieve removal of bioburden only at the macroscopic level while leaving behind molecular levels of contamination (mainly proteinaceous). This is of particular concern if the residue might contain prions. We investigated at the molecular level the removal of model and real-life proteinaceous contamination from model and practical surfaces by air plasma (ionised air) treatment. The surface-sensitive technique of X-ray photoelectron spectroscopy (XPS) was used to assess the removal of proteinaceous contamination, with the nitrogen (N1s) photoelectron signal as its marker. Model proteinaceous contamination (bovine serum albumin) adsorbed on to a model surface (silicon wafer) and the residual proteinaceous contamination resulting from incubating surgical stainless steel (a practical biomaterial) in whole human blood exhibited strong N1s signals [16.8 and 18.5 atomic percent (at.%), respectively] after thorough washing. After 5min air plasma treatment, XPS detected no nitrogen on the sample surfaces, indicating complete removal of proteinaceous contamination, down to the estimated XPS detection limit 10ng/cm(2). Applying the same plasma treatment, the 7.7at.% nitrogen observed on a clinically cleaned dental bur was reduced to a level reflective of new, as-received burs. Contact angle measurements and atomic force microscopy also indicated complete molecular-level removal of the proteinaceous contamination upon air plasma treatment. This study demonstrates the effectiveness of air plasma treatment for removing proteinaceous contamination from both model and practical surfaces and offers a method for ensuring that no molecular residual contamination such as prions is transferred upon re-use of surgical and dental instruments. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Secondary ion mass spectrometry (SIMS) analysis of hypervelocity microparticle impact sites on LDEF surfaces

NASA Technical Reports Server (NTRS)

Simon, C. G.; Buonaquisti, A. J.; Batchelor, D. A.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. R.; Wortman, J. J.; Brownlee, D. E.; Best, S. R.

1995-01-01

Two dimensional elemental ion maps have been recorded for hundreds of microparticle impact sites and contamination features on LDEF surfaces. Since the majority of the analyzed surfaces were metal-oxide-silicon (MOS) impact detectors from the Interplanetary Dust Experiment, a series of 'standard' and 'blank' analyses of these surfaces are included. Hypervelocity impacts of forsterite olivine microparticles on activated flight sensors served as standards while stylus and pulsed laser simulated 'impacts' served as analytical blanks. Results showed that despite serious contamination issues, impactor residues can be identified in greater than 1/3 of the impact sites. While aluminum oxide particles could not be detected on aluminum surfaces, they were detected on germanium surfaces from row 12. Remnants of manmade debris impactors consisting of paint chips and bits of metal were identified on surfaces from LDEF Rows 3 (west or trailing side), 6 (south), 9 (ram or leading side), 12 (north) and the space end. Higher than expected ratios of manmade microparticle impacts to total microparticle impacts were found on the space end and the trailing side. These results were consistent with time-tagged and time-segregated microparticle impact data from the IDE and other LDEF experiments. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences include pre-, post and inflight deposited surface contaminants as well as indigenous heterogeneous material contaminants. Non-flight contaminations traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF, even on a micro scale. In-flight deposited (low velocity) contaminants include urine droplets and bits of metal film from eroded thermal blankets.

Assessment of a handheld fluorescence imaging device as a visual-aid for detection of food residues on processing surfaces

USDA-ARS?s Scientific Manuscript database

Contamination of food with pathogenic bacteria can lead to foodborne illnesses. Food processing surfaces can serve as a medium for cross-contamination if sanitization procedures are inadequate. Ensuring that food processing surfaces are correctly cleaned and sanitized is important in the food indust...

Detection of Campylobacter on the outer surface of retail broiler meat packages and from the exudate within

USDA-ARS?s Scientific Manuscript database

Previous work has suggested that outer surfaces of retail broiler meat packaging may be contaminated with Campylobacter presenting a potential hazard to the consumer through direct transfer or by cross contamination of other products or surfaces. The objectives of this study were to measure the pre...

Overview of Chemicals of Emerging Concern

EPA Science Inventory

Contaminants of emerging concern or environmental emerging contaminants, are chemicals, products and materials that are detected with increasing frequency in all environmental media including surface, ground water and drinking water. Examples of these contaminants include pharmac...

Expanded Target-Chemical Analysis Reveals Extensive Mixed-Organic-Contaminant Exposure in U.S. Streams

EPA Science Inventory

Surface-water from 38 streams nation-wide was assessed using 14 target-organic methods (719 compounds). Designedbioactive anthropogenic contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics detected at least once. The 10 most-frequently detected anthropogenic-org...

Determination of the external contamination and cross-contamination by cytotoxic drugs on the surfaces of vials available on the Swiss market.

PubMed

Fleury-Souverain, Sandrine; Nussbaumer, Susanne; Mattiuzzo, Marc; Bonnabry, Pascal

2014-04-01

The external contamination and cross-contamination by cytotoxic drugs on the surface (outside and septum) of 133 vials from various manufacturers and available on the Swiss market were evaluated. All of the tested vials contained one of the following active ingredients: cyclophosphamide, cytarabine, doxorubicin, epirubicin, etoposide phosphate, gemcitabine, ifosfamide, irinotecan, methotrexate or vincristine. The validated wiping liquid chromatography-mass spectrometry method used in this study allowed for the simultaneous determination of these 10 cytotoxic drugs in less than 30 min. External contamination by cytotoxic drugs was detected on 63% of tested vials (outside and septum). The highest contamination level was observed on etoposide phosphate vials with 1896.66 ng of active ingredient on the outside of the vial. Approximately 20% of the contaminated vials had greater than 10 ng of cytotoxic drugs. Chemical contamination on the septum was detected on 38% of the vials. No contamination or very low levels of cytotoxic drugs, less than 1 ng per vial, were detected on the vials protected by plastic shrink-wrap. Traces of cytotoxic drugs different from the active ingredient were detected on 35% of the tested vials. Handling cytotoxic vials with gloves and having a procedure for the decontamination of vials are of the utmost importance for reducing exposure to cytotoxic drugs. Moreover, manufacturers must improve their procedures to provide products free from any contamination.

Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

NASA Astrophysics Data System (ADS)

Oh, Mirae; Lee, Hoonsoo; Cho, Hyunjeong; Moon, Sang-Ho; Kim, Eun-Kyung; Kim, Moon S.

2016-05-01

Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by highlighting contaminated food and food contact surfaces on a display monitor. It can be used under ambient lighting conditions in food processing plants. Critical components of the imaging device includes four 405-nm 10-W LEDs for fluorescence excitation, a charge-coupled device (CCD) camera, optical filter (670 nm used for this study), and Wi-Fi transmitter for broadcasting real-time video/images to monitoring devices such as smartphone and tablet. This study aimed to investigate the effectiveness of HFID in enhancing visual detection of fecal contamination on red meat, fat, and bone surfaces of beef under varying ambient luminous intensities (0, 10, 30, 50 and 70 foot-candles). Overall, diluted feces on fat, red meat and bone areas of beef surfaces were detectable in the 670-nm single-band fluorescence images when using the HFID under 0 to 50 foot-candle ambient lighting.

Bond Testing for Effects of Silicone Contamination

NASA Technical Reports Server (NTRS)

Plaia, James; Evans, Kurt

2005-01-01

In 2003 ATK Thiokol discovered that the smocks and coveralls worn by its operations personnel for safety and contamination control were themselves contaminated with a silicone defoamer and a silicone oil. As a growing list of items have been identified as having this form of contamination, it was desirable to devise a test method to determine if the contamination level detected could cause subsequent processing concerns. The smocks and coveralls could potentially contact bonding surfaces during processing so the test method focused on dry transfer of the silicone from the clothing to the bonding surface.

Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater-facility-impacted stream reach.

PubMed

Bradley, Paul M; Barber, Larry B; Clark, Jimmy M; Duris, Joseph W; Foreman, William T; Furlong, Edward T; Givens, Carrie E; Hubbard, Laura E; Hutchinson, Kasey J; Journey, Celeste A; Keefe, Steffanie H; Kolpin, Dana W

2016-10-15

Pharmaceutical contamination of contiguous groundwater is a substantial concern in wastewater-impacted streams, due to ubiquity in effluent, high aqueous mobility, designed bioactivity, and to effluent-driven hydraulic gradients. Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insights into contaminant persistence, long-term wastewater impacts, and ecosystem recovery processes. The USGS conducted a combined pre/post-closure groundwater assessment adjacent to an effluent-impacted reach of Fourmile Creek, Ankeny, Iowa, USA. Higher surface-water concentrations, consistent surface-water to groundwater concentration gradients, and sustained groundwater detections tens of meters from the stream bank demonstrated the importance of WWTF effluent as the source of groundwater pharmaceuticals as well as the persistence of these contaminants under effluent-driven, pre-closure conditions. The number of analytes (110 total) detected in surface water decreased from 69 prior to closure down to 8 in the first post-closure sampling event approximately 30 d later, with a corresponding 2 order of magnitude decrease in the cumulative concentration of detected analytes. Post-closure cumulative concentrations of detected analytes were approximately 5 times higher in proximal groundwater than in surface water. About 40% of the 21 contaminants detected in a downstream groundwater transect immediately before WWTF closure exhibited rapid attenuation with estimated half-lives on the order of a few days; however, a comparable number exhibited no consistent attenuation during the year-long post-closure assessment. The results demonstrate the potential for effluent-impacted shallow groundwater systems to accumulate pharmaceutical contaminants and serve as long-term residual sources, further increasing the risk of adverse ecological effects in groundwater and the near-stream ecosystem. Published by Elsevier B.V.

Pre/post-closure assessment of groundwater pharmaceutical fate in a wastewater‑facility-impacted stream reach

USGS Publications Warehouse

Bradley, Paul M.; Barber, Larry B.; Clark, Jimmy M.; Duris, Joseph W.; Foreman, William T.; Furlong, Edward T.; Givens, Carrie E.; Hubbard, Laura E.; Hutchinson, Kasey J.; Journey, Celeste A.; Keefe, Steffanie H.; Kolpin, Dana W.

2016-01-01

Pharmaceutical contamination of contiguous groundwater is a substantial concern in wastewater-impacted streams, due to ubiquity in effluent, high aqueous mobility, designed bioactivity, and to effluent-driven hydraulic gradients. Wastewater treatment facility (WWTF) closures are rare environmental remediation events; offering unique insights into contaminant persistence, long-term wastewater impacts, and ecosystem recovery processes. The USGS conducted a combined pre/post-closure groundwater assessment adjacent to an effluent-impacted reach of Fourmile Creek, Ankeny, Iowa, USA. Higher surface-water concentrations, consistent surface-water to groundwater concentration gradients, and sustained groundwater detections tens of meters from the stream bank demonstrated the importance of WWTF effluent as the source of groundwater pharmaceuticals as well as the persistence of these contaminants under effluent-driven, pre-closure conditions. The number of analytes (110 total) detected in surface water decreased from 69 prior to closure down to 8 in the first post-closure sampling event approximately 30 d later, with a corresponding 2 order of magnitude decrease in the cumulative concentration of detected analytes. Post-closure cumulative concentrations of detected analytes were approximately 5 times higher in proximal groundwater than in surface water. About 40% of the 21 contaminants detected in a downstream groundwater transect immediately before WWTF closure exhibited rapid attenuation with estimated half-lives on the order of a few days; however, a comparable number exhibited no consistent attenuation during the year-long post-closure assessment. The results demonstrate the potential for effluent-impacted shallow groundwater systems to accumulate pharmaceutical contaminants and serve as long-term residual sources, further increasing the risk of adverse ecological effects in groundwater and the near-stream ecosystem.

Capabilities of the Materials Contamination Team at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Burns, Howard; Albyn, Keith; Edwards, David; Boothe, Richard; Finchum, Charles; Finckenor, Miria

2003-01-01

The Materials Contamination Team at the Marshall Space Flight Center (MSFC) has been recognized for its contributions supporting the National Aeronautics and Space Administration (NASA) spacecraft development programs. These programs include the Reusable Solid Rocket Motor (RSRM), Chandra X-Ray Observatory, and the International Space Station (ISS). The Environmental Effects Group, with the Materials Contamination Team and the Space Environmental Effects Team has been an integral part of NASA's success by the testing, evaluation, and qualification of materials, hardware, and processes. This paper focuses on the capabilities of the Materials Contamination Team. The Materials Contamination Team's realm of responsibility includes establishing contamination control during all phases of hardware development, including design, manufacturing, assembly, test, transportation, launch site processing, on-orbit exposure, return, and refurbishment. The team continues its mission of reducing the risk of equipment failure due to molecular or particulate contamination. Contamination is a concern in the Space Shuttle with sensitive bond-lines and reactive fluid (liquid oxygen) compatibility as well as for spacecraft with sensitive optics, such as Hubble Space Telescope and Chandra X-ray Observatory. The Materials Contamination Team has a variety of facilities and instrumentation capable of contaminant detection, identification, and monitoring. The team addresses material applications dealing with environments, including production facilities, clean rooms, and on-orbit exposure. The optically stimulated electron emission (OSEE) system, the Ultraviolet (UV) fluorescence (UVF) surface contamination detection, and the Surface Optics Corporation 400 (SOC 400) portable hand-held Fourier Transform Infrared (FTIR) spectrometer are state-of-the-art tools for in-process molecular contamination detection. The team of engineers and technicians also develop contamination calibration standards and evaluate new surface cleanliness inspection technologies. The team utilizes facilities for on-orbit simulation testing of materials for outgassing and molecular film deposition characteristics in the presence of space environmental effects, such as Atomic Oxygen (AO) and UV radiation exposure. The Materials Contamination Team maintains databases for process materials as well as outgassing and optical compatibility test results for specific environments.

Multicenter evaluation of a new closed system drug-transfer device in reducing surface contamination by antineoplastic hazardous drugs.

PubMed

Bartel, Sylvia B; Tyler, Timothy G; Power, Luci A

2018-02-15

Results of a study to evaluate the effectiveness of a recently introduced closed system drug-transfer device (CSTD) in reducing surface contamination during compounding and simulated administration of antineoplastic hazardous drugs (AHDs) are reported. Wipe samples were collected from 6 predetermined surfaces in compounding and infusion areas of 13 U.S. cancer centers to establish preexisting levels of surface contamination by 2 marker AHDs (cyclophosphamide and fluorouracil). Stainless steel templates were placed over the 6 previously sampled surfaces, and the marker drugs were compounded and infused per a specific protocol using all components of the CSTD. Wipe samples were collected from the templates after completion of tasks and analyzed for both marker AHDs. Aggregated results of wipe sampling to detect preexisting contamination at the 13 study sites showed that overall, 66.7% of samples (104 of 156) had detectable levels of at least 1 marker AHD; subsequent testing after CSTD use per protocol found a sample contamination rate of 5.8% (9 of 156 samples). In the administration areas alone, the rate of preexisting contamination was 78% (61 of 78 samples); with use of the CSTD protocol, the contamination rate was 2.6%. Twenty-six participants rated the CSTD for ease of use, with 100% indicating that they were satisfied or extremely satisfied. A study involving a rigorous protocol and 13 cancer centers across the United States demonstrated that the CSTD reduced surface contamination by cyclophosphamide and fluorouracil during compounding and simulated administration. Participants reported that the CSTD was easy to use. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Enhanced Detection of Surface-Associated Bacteria in Indoor Environments by Quantitative PCR

PubMed Central

Buttner, Mark P.; Cruz-Perez, Patricia; Stetzenbach, Linda D.

2001-01-01

Methods for detecting microorganisms on surfaces are needed to locate biocontamination sources and to relate surface and airborne concentrations. Research was conducted in an experimental room to evaluate surface sampling methods and quantitative PCR (QPCR) for enhanced detection of a target biocontaminant present on flooring materials. QPCR and culture analyses were used to quantitate Bacillus subtilis (Bacillus globigii) endospores on vinyl tile, commercial carpet, and new and soiled residential carpet with samples obtained by four surface sampling methods: a swab kit, a sponge swipe, a cotton swab, and a bulk method. The initial data showed that greater overall sensitivity was obtained with the QPCR than with culture analysis; however, the QPCR results for bulk samples from residential carpet were negative. The swab kit and the sponge swipe methods were then tested with two levels of background biological contamination consisting of Penicillium chrysogenum spores. The B. subtilis values obtained by the QPCR method were greater than those obtained by culture analysis. The differences between the QPCR and culture data were significant for the samples obtained with the swab kit for all flooring materials except soiled residential carpet and with the sponge swipe for commercial carpet. The QPCR data showed that there were no significant differences between the swab kit and sponge swipe sampling methods for any of the flooring materials. Inhibition of QPCR due solely to biological contamination of flooring materials was not evident. However, some degree of inhibition was observed with the soiled residential carpet, which may have been caused by the presence of abiotic contaminants, alone or in combination with biological contaminants. The results of this research demonstrate the ability of QPCR to enhance detection and enumeration of biocontaminants on surface materials and provide information concerning the comparability of currently available surface sampling methods. PMID:11375164

Automated on-line fecal detection - digital eye guards against fecal contamination

USDA-ARS?s Scientific Manuscript database

Agricultural Research Service scientists in Athens, GA., have been granted a patent on a method to detect contaminants on food surfaces with imaging systems. Using a real-time imaging system in the processing plant, researchers Bob Windham, Kurt, Lawrence, Bosoon Park, and Doug Smith in the ARS Poul...

Detecting contaminating microorganism in human food and water from Raman mapping through biofilms

USDA-ARS?s Scientific Manuscript database

Detecting microbial growth can help experts determine how to prevent the outbreaks especially if human food or water has been contaminated. Biofilms are a group of microbial cells that can either grow on living surfaces or surrounding themselves as they progress. Biofilms are not necessarily uniform...

Contaminants of emerging concern in surface waters in Barbados, West Indies.

PubMed

Edwards, Quincy A; Kulikov, Sergei M; Garner-O'Neale, Leah D; Metcalfe, Chris D; Sultana, Tamanna

2017-11-14

Contaminants of emerging concern (CECs), including pharmaceuticals, artificial sweeteners, steroid hormones, and current-use pesticides have been detected in surface waters around the world, but to date, there have been no reports in the peer-reviewed literature on the levels of these classes of contaminants in freshwater resources in the Caribbean region. In the present study, multi-residue solid phase extraction (SPE) and liquid chromatography with tandem mass spectroscopy (LC-MS/MS) were used to analyze grab samples of surface waters collected from five different watersheds in Barbados, West Indies. The artificial sweeteners (AS), acesulfame, cyclamate, saccharin, and sucralose were widely detected in the watersheds, indicating contamination from domestic wastewater, and the concentrations of these chemical tracers in water were correlated with the concentrations of the non-prescription pharmaceutical, ibuprofen (R 2 values of 0.4-0.6). Surprisingly, the concentrations of another chemical tracer of domestic wastewater, caffeine were not correlated with ibuprofen or AS concentrations. Several other prescription pharmaceuticals and the steroid hormones, estrone and androstenedione, were detected in selected watersheds at low ng/L concentrations. The fungicide, chlorothalonil was widely detected in surface waters at low (< 10 ng/L) concentrations, but the levels of this pesticide were not correlated with the concentrations of the other target analytes, indicating that the source of this pesticide is not domestic wastewater. An informal survey of disposal practices for out of date or unused drugs by pharmacies in Barbados indicated that disposal into trash destined for the landfill and flushing down the sink might be significant sources of contamination of water resources by pharmaceuticals.

Assessment of Soil-Gas, Surface-Water, and Soil Contamination at the Installation Railhead, Fort Gordon, Georgia, 2008-2009

USGS Publications Warehouse

Landmeyer, James E.; Harrelson, Larry G.; Ratliff, W. Hagan; Wellborn, John B.

2010-01-01

The U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, assessed soil gas, surface water, and soil for contaminants at the Installation Railhead (IR) at Fort Gordon, Georgia, from October 2008 to September 2009. The assessment included delineation of organic contaminants present in soil-gas samples beneath the IR, and in a surface-water sample collected from an unnamed tributary to Marcum Branch in the western part of the IR. Inorganic contaminants were determined in a surface-water sample and in soil samples. This assessment was conducted to provide environmental contamination data to Fort Gordon personnel pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Soil-gas samples collected within a localized area on the western part of the IR contained total petroleum hydrocarbons; benzene, toluene, ethylbenzene, and total xylenes (referred to as BTEX); and naphthalene above the method detection level. These soil-gas samples were collected where buildings had previously stood. Soil-gas samples collected within a localized area contained perchloroethylene (PCE). These samples were collected where buildings 2410 and 2405 had been. Chloroform and toluene were detected in a surface-water sample collected from an unnamed tributary to Marcum Branch but at concentrations below the National Primary Drinking Water Standard maximum contaminant level (MCL) for each compound. Iron was detected in the surface-water sample at 686 micrograms per liter (ug/L) and exceeded the National Secondary Drinking Water Standard MCL for iron. Metal concentrations in composite soil samples collected at three locations from land surface to a depth of 6 inches did not exceed the U.S. Environmental Protection Agency Regional Screening Levels for industrial soil.

Assessment of trace element contamination of urban surface soil at informal industrial sites in a low-income country.

PubMed

Kanda, Artwell; Ncube, France; Hwende, Tamuka; Makumbe, Peter

2018-05-29

Trace elements released by human activity are ubiquitously detected in surface soil. The trace element contamination statuses of 20 sampling stations at two busy informal industrial sites of Harare city, Zimbabwe, were evaluated using geochemical indices. Spectrophotometric determinations of concentrations of trace elements in surface soil indicated generally higher values than the reference site and the average upper earth's crust. High contamination factors were observed for trace elements across sampling stations at Gazaland and Siyaso informal industrial sites. Concentrations exhibited heterogeneous distribution of trace elements in surface soil varying with the nature of activity at a sampling station. The pollution load index and degree of contamination suggested highly contaminated surface soil with Cd, Cu and Pb particularly where the following activities were done: (1) welding, (2) automobile maintenance and (3) waste dumping. These results may be very important to reduce soil contamination. Paving surfaces may help to reduce dispersal of trace elements deposited on surface soil to other stations and minimise human exposure via inhalation and contact.

Hyperspectral Analysis for Standoff Detection of Dimethyl ...

EPA Pesticide Factsheets

Journal Article Detecting organophosphates in indoor settings requires more efficient and faster methods of surveying large surface areas than conventional approaches, which sample small surface areas followed by extraction and analysis. This study examined a standoff detection technique utilizing hyperspectral imaging for analysis of building materials in near-real time. In this proof-of-concept study, dimethyl methylphosphonate (DMMP) was applied to stainless steel and laminate coupons and spectra were collected during active illumination. Absorbance bands at approximately 1275 cm-1 and 1050 cm-1 were associated with phosphorus-oxygen double bond (P=O) and phosphorus-oxygen-carbon (P-O-C) bond stretches of DMMP, respectively. The magnitude of these bands increased linearly (r2 = 0.93) with DMMP across the full absorbance spectrum, between ν1 = 877 cm-1 to ν2 = 1262 cm-1. Comparisons between bare and contaminated surfaces on stainless steel using the spectral contrast angle technique indicated that the bare samples showed no sign of contamination, with large uniformly distributed contrast angles of 45˚-55˚, while the contaminated samples had smaller spectral contact angles of 40° in the uncontaminated region. The laminate contaminated region exhibited contact angles of < 25°. To the best of our knowledge, this is the first report to demonstrate that hyperspectral imaging can be used to detect DMMP on building materials, with detection levels similar to c

Modified Pressure Imaging for Egg Crack Detection and Resulting Egg Quality

USDA-ARS?s Scientific Manuscript database

Cracks in the shell surface impair the primary barrier for external microbial contamination of the egg. Microcracks are very small cracks in the shell surface which are difficult to detect by human graders. New technology has been developed which utilizes modified pressure and imaging to detect mi...

Preparation of TNT, RDX and Ammonium Nitrate Standards on Gold-on-Silicon Surfaces by Thermal Inkjet Technology

NASA Astrophysics Data System (ADS)

Wrable-Rose, Madeline; Primera-Pedrozo, Oliva M.; Pacheco-Londoño, Leonardo C.; Hernandez-Rivera, Samuel P.

2010-12-01

This research examines the surface contamination properties, trace sample preparation methodologies, detection systems response and generation of explosive contamination standards for trace detection systems. Homogeneous and reproducible sample preparation is relevant for trace detection of chemical threats, such as warfare agents, highly energetic materials (HEM) and toxic industrial chemicals. The objective of this research was to develop a technology capable of producing samples and standards of HEM with controlled size and distribution on a substrate to generate specimens that would reproduce real contamination conditions. The research activities included (1) a study of the properties of particles generated by two deposition techniques: sample smearing deposition and inkjet deposition, on gold-coated silicon, glass and stainless steel substrates; (2) characterization of composition, distribution and adhesion characteristics of deposits; (3) evaluation of accuracy and reproducibility for depositing neat highly energetic materials such as TNT, RDX and ammonium nitrate; (4) a study of HEM-surface interactions using FTIR-RAIRS; and (5) establishment of protocols for validation of surface concentration using destructive methods such as HPLC.

Semi-automated detection of trace explosives in fingerprints on strongly interfering surfaces with Raman chemical imaging.

PubMed

Tripathi, Ashish; Emmons, Erik D; Wilcox, Phillip G; Guicheteau, Jason A; Emge, Darren K; Christesen, Steven D; Fountain, Augustus W

2011-06-01

We have previously demonstrated the use of wide-field Raman chemical imaging (RCI) to detect and identify the presence of trace explosives in contaminated fingerprints. In this current work we demonstrate the detection of trace explosives in contaminated fingerprints on strongly Raman scattering surfaces such as plastics and painted metals using an automated background subtraction routine. We demonstrate the use of partial least squares subtraction to minimize the interfering surface spectral signatures, allowing the detection and identification of explosive materials in the corrected Raman images. The resulting analyses are then visually superimposed on the corresponding bright field images to physically locate traces of explosives. Additionally, we attempt to address the question of whether a complete RCI of a fingerprint is required for trace explosive detection or whether a simple non-imaging Raman spectrum is sufficient. This investigation further demonstrates the ability to nondestructively identify explosives on fingerprints present on commonly found surfaces such that the fingerprint remains intact for further biometric analysis.

Organochlorine insecticide residues are found in surface, irrigated water samples from several districts in Bangladesh.

PubMed

Chowdhury, Alamgir Zaman; Islam, Mohammad Nazrul; Moniruzzaman, Mohammed; Gan, Siew Hua; Alam, Md Khorshed

2013-02-01

The purpose of this study was to investigate the occurrence and distribution of organochlorines such as aldrin, dieldrin, dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyltrichloroethane (DDT), endrin, lindane and heptachlor insecticide residues in irrigated surface water samples collected from 22 districts in Bangladesh. The concentrations of the pesticides were determined using gas chromatography mass spectrophotometry. Water samples from five locations (Feni, Nawabganj, Putia, Burichang and Chatak) were contaminated with DDT; the highest DDT concentration detected was 8.29 μg/L, and its metabolite, DDE, was detected at 4.06 μg/L. Water samples from four other locations (Natore, Sikderpara, Chatak and Rajoir) were contaminated with heptachlor residues, and the highest level detected was 5.24 μg/L, which is the above the maximum contaminant level recommended by the World Health Organisation. A water sample collected from Chatak, Sunamganj, was contaminated with both DDT and heptachlor pesticide residues. None of the water samples were contaminated with aldrin, DDD, dieldrin, endrin or lindane. It is concluded that continuous, long-term monitoring and essential steps to limit the use of the pesticides in Bangladesh are needed.

Visible-light system for detecting doxorubicin contamination on skin and surfaces.

PubMed

Van Raalte, J; Rice, C; Moss, C E

1990-05-01

A portable system that uses fluorescence stimulated by visible light to identify doxorubicin contamination on skin and surfaces was studied. When activated by violet-blue light in the 465-nm range, doxorubicin fluoresces, emitting orange-red light in the 580-nm range. The light source to stimulate fluorescence was a slide projector with a filter to selectively pass short-wave (blue) visible light. Fluorescence was both observed visually with viewing spectacles and photographed. Solutions of doxorubicin in sterile 0.9% sodium chloride injection were prepared in nine standard concentrations ranging from 2 to 0.001 mg/mL. Droplets of each admixture were placed on stainless steel, laboratory coat cloth, pieces of latex examination glove, bench-top absorbent padding, and other materials on which antineoplastics might spill or leak. These materials then were stored for up to eight weeks and photographed weekly. The relative ability of water, household bleach, hydrogen peroxide solution, and soap solution to deactivate doxorubicin was also measured. Finally, this system was used to inspect the antineoplastic-drug preparation and administration areas of three outpatient cancer clinics for doxorubicin contamination. Doxorubicin fluorescence was easily detectable with viewing spectacles when a slide projector was used as the light source. The photographic method was sensitive for doxorubicin concentrations from 2.0 to 0.001 mg/mL. Immersion of study materials in bleach for one minute eliminated detectable fluorescence. Doxorubicin contamination is detectable for at least eight weeks in the ambient environment. Probable doxorubicin contamination was detected in two of the three clinics surveyed. A safe, portable system that uses fluorescence stimulated by visible light is a sensitive method for detecting doxorubicin on skin and surfaces.

Residual Silicone Detection. [external tank and solid rocket booster surfaces

NASA Technical Reports Server (NTRS)

Smith, T.

1980-01-01

Both photoelectron emission and ellipsometry proved successful in detecting silicone contamination on unpainted and epoxy painted metal surfaces such as those of the external tank and the solid rocket booster. Great success was achieved using photoelectron emission (PEE). Panels were deliberately contaminated to controlled levels and then mapped with PEE to reveal the areas and levels that were contaminated. The panels were then tested with regard to adhesive properties. Tapes were bonded over the contaminated and uncontaminated regions and the peel force was measured, or the contaminated panels were bonded (with CPR 483 foam) to uncontaminated panels and made into lap shear specimens. Other panels were bonded and made into wedge specimens for hydrothermal stress endurance tests. Strong adhesion resulted if the PEE signal fell within an acceptance window, but was poor outside the acceptance window. A prototype instrument is being prepared which can automatically be scanned over the external liquid hydrogen tank and identify those regions that are contaminated and will cause bond degradation.

Effects of the contamination environment on surfaces and materials

NASA Technical Reports Server (NTRS)

Maag, Carl R.

1989-01-01

In addition to the issues that have always existed, demands are being placed on space systems for increased contamination prevention/control. Optical surveillance sensors are required to detect low radiance targets. This increases the need for very low scatter surfaces in the optical system. Particulate contamination levels typically experienced in today's working environments/habits will most likely compromise these sensors. Contamination (molecular and particulate) can also affect the survivability of space sensors in both the natural and hostile space environments. The effects of di-octyl phthalate (DOP) on sensors are discussed.

Linking otolith microchemistry and surface water contamination from natural gas mining.

PubMed

Keller, David H; Zelanko, Paula M; Gagnon, Joel E; Horwitz, Richard J; Galbraith, Heather S; Velinsky, David J

2018-09-01

Unconventional natural gas drilling and the use of hydraulic fracturing technology have expanded rapidly in North America. This expansion has raised concerns of surface water contamination by way of spills and leaks, which may be sporadic, small, and therefore difficult to detect. Here we explore the use of otolith microchemistry as a tool for monitoring surface water contamination from generated waters (GW) of unconventional natural gas drilling. We exposed Brook Trout in the laboratory to three volumetric concentrations of surrogate generated water (SGW) representing GW on day five of drilling. Transects across otolith cross-sections were analyzed for a suite of elements by LA-ICP-MS. Brook Trout exposed to a 0.01-1.0% concentration of SGW for 2, 15, and 30 days showed a significant (p < 0.05) relationship of increasing Sr and Ba concentrations in all but one treatment. Analyses indicate lesser concentrations than used in this experiment could be detectable in surface waters and provide support for the use of this technique in natural habitats. To our knowledge, this is the first demonstration of how trace elements in fish otoliths may be used to monitor for surface water contamination from GW. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electronic Noses for Composites Surface Contamination Detection in Aerospace Industry

PubMed Central

De Vito, Saverio; Miglietta, Maria Lucia; Massera, Ettore; Fattoruso, Grazia; Formisano, Fabrizio; Polichetti, Tiziana; Salvato, Maria; Alfano, Brigida; Esposito, Elena; Di Francia, Girolamo

2017-01-01

The full exploitation of Composite Fiber Reinforced Polymers (CFRP) in so-called green aircrafts design is still limited by the lack of adequate quality assurance procedures for checking the adhesive bonding assembly, especially in load-critical primary structures. In this respect, contamination of the CFRP panel surface is of significant concern since it may severely affect the bonding and the mechanical properties of the joint. During the last years, the authors have developed and tested an electronic nose as a non-destructive tool for pre-bonding surface inspection for contaminants detection, identification and quantification. Several sensors and sampling architectures have been screened in view of the high Technology Readiness Level (TRL) scenarios requirements. Ad-hoc pattern recognition systems have also been devised to ensure a fast and reliable assessment of the contamination status, by combining real time classifiers and the implementation of a suitable rejection option. Results show that e-noses could be used as first line low cost Non Destructive Test (NDT) tool in aerospace CFRP assembly and maintenance scenarios. PMID:28368338

Electronic Noses for Composites Surface Contamination Detection in Aerospace Industry.

PubMed

Vito, Saverio De; Miglietta, Maria Lucia; Massera, Ettore; Fattoruso, Grazia; Formisano, Fabrizio; Polichetti, Tiziana; Salvato, Maria; Alfano, Brigida; Esposito, Elena; Francia, Girolamo Di

2017-04-02

The full exploitation of Composite Fiber Reinforced Polymers (CFRP) in so-called green aircrafts design is still limited by the lack of adequate quality assurance procedures for checking the adhesive bonding assembly, especially in load-critical primary structures. In this respect, contamination of the CFRP panel surface is of significant concern since it may severely affect the bonding and the mechanical properties of the joint. During the last years, the authors have developed and tested an electronic nose as a non-destructive tool for pre-bonding surface inspection for contaminants detection, identification and quantification. Several sensors and sampling architectures have been screened in view of the high Technology Readiness Level (TRL) scenarios requirements. Ad-hoc pattern recognition systems have also been devised to ensure a fast and reliable assessment of the contamination status, by combining real time classifiers and the implementation of a suitable rejection option. Results show that e-noses could be used as first line low cost Non Destructive Test (NDT) tool in aerospace CFRP assembly and maintenance scenarios.

Occurrence and potential health risk of Cryptosporidium and Giardia in different water catchments in Belgium.

PubMed

Ehsan, Amimul; Geurden, Thomas; Casaert, Stijn; Paulussen, Jef; De Coster, Lut; Schoemaker, Toon; Chalmers, Rachel; Grit, Grietje; Vercruysse, Jozef; Claerebout, Edwin

2015-02-01

Human wastewater and livestock can contribute to contamination of surface water with Cryptosporidium and Giardia. In countries where a substantial proportion of drinking water is produced from surface water, e.g., Belgium, this poses a constant threat on drinking water safety. Our objective was to monitor the presence of Cryptosporidium and Giardia in different water catchment sites in Belgium and to discriminate between (oo)cysts from human or animal origin using genotyping. Monthly samples were collected from raw water and purified drinking water at four catchment sites. Cryptosporidium and Giardia were detected using USEPA method 1623 and positive samples were genotyped. No contamination was found in purified water at any site. In three catchments, only low numbers of (oo)cysts were recovered from raw water samples (<1/liter), but raw water samples from one catchment site were frequently contaminated with Giardia (92 %) and Cryptosporidium (96 %), especially in winter and spring. Genotyping of Giardia in 38 water samples identified the presence of Giardia duodenalis assemblage AI, AII, BIV, BIV-like, and E. Cryptosporidium andersoni, Cryptosporidium suis, Cryptosporidium horse genotype, Cryptosporidium parvum, and Cryptosporidium hominis were detected. The genotyping results suggest that agriculture may be a more important source of surface water contamination than human waste in this catchment. In catchment sites with contaminated surface water, such as the Blankaart, continuous monitoring of treated water for the presence of Cryptosporidium and Giardia would be justified and (point) sources of surface water contamination should be identified.

Fast and accurate image recognition algorithms for fresh produce food safety sensing

NASA Astrophysics Data System (ADS)

Yang, Chun-Chieh; Kim, Moon S.; Chao, Kuanglin; Kang, Sukwon; Lefcourt, Alan M.

2011-06-01

This research developed and evaluated the multispectral algorithms derived from hyperspectral line-scan fluorescence imaging under violet LED excitation for detection of fecal contamination on Golden Delicious apples. The algorithms utilized the fluorescence intensities at four wavebands, 680 nm, 684 nm, 720 nm, and 780 nm, for computation of simple functions for effective detection of contamination spots created on the apple surfaces using four concentrations of aqueous fecal dilutions. The algorithms detected more than 99% of the fecal spots. The effective detection of feces showed that a simple multispectral fluorescence imaging algorithm based on violet LED excitation may be appropriate to detect fecal contamination on fast-speed apple processing lines.

Using Contaminant Transport Simulations to Optimize Electrical Resistivity Tomography Survey Design for Improved Contaminant Detection at Lined Ponds

NASA Astrophysics Data System (ADS)

Herring, T.; Pidlisecky, A.

2015-12-01

The saline flowback water produced during hydraulic fracturing is often stored in lined surface ponds. Leakage from these ponds poses a significant environmental threat and there is a need for a reliable and economical long term monitoring strategy. Electrical resistivity tomography (ERT), being sensitive to changes in groundwater salinity, is therefore well suited to such a problem. The goal of this work is to compare the leak detection capabilities of a surface ERT array and a downhole ERT array. In this study several plausible 3D electrical conductivity models were created that simulated a contaminant plume evolving over time, using realistic contaminant concentrations, plume geometries, water saturation profiles, and seasonal temperature profiles. The forward modeled data were used to identify the advantages and drawbacks of using each ERT array orientation.

Surface-Water to Groundwater Transport of Pharmaceuticals in a Wastewater-Impacted Stream in the U.S.

NASA Astrophysics Data System (ADS)

Bradley, P. M.; Barber, L. B.; Duris, J. W.; Foreman, W. T.; Furlong, E. T.; Hubbard, L. E.; Hutchinson, K. J.; Keefe, S. H.; Kolpin, D. W.

2014-12-01

Wastewater pharmaceutical contamination of shallow groundwater is a substantial concern in effluent-dominated streams, due to aqueous mobility and designed bioactivity of pharmaceuticals and due to effluent-driven hydraulic gradients. Improved understanding of the environmental fate and transport of wastewater-derived pharmaceuticals is essential for effective protection of vital aquatic ecosystem services, environmental health, and drinking-water supplies. Substantial longitudinal (downstream) transport of pharmaceutical contaminants has been documented in effluent-impacted streams. The comparative lack of information on vertical and lateral transport (infiltration) of wastewater contaminants from surface-water to hyporheic and shallow groundwater compartments is a critical scientific data gap, given the potential for contamination of groundwater supplies in effluent-impacted systems. Growing dependencies on bank filtration and artificial recharge applications for release of wastewater to the environment and for pretreatment of poor-quality surface-water for drinking water emphasize the critical need to better understand the exchange of wastewater contaminants, like pharmaceuticals, between surface-water and groundwater compartments. The potential transport of effluent-derived pharmaceutical contaminants from surface-water to hyporheic-water and shallow groundwater compartments was examined in a wastewater-treatment-facility (WWTF) impacted stream in Ankeny, Iowa under effluent-dominated (71-99% of downstream flow) conditions. Strong hydraulic gradients and hydrologic connectivity were evident between surface-water and shallow-groundwater compartments in the vicinity of the WWTF outfall. Carbamazepine, sulfamethoxazole, and immunologically-related compounds were detected in groundwater 10-20 meters from the stream bank. Direct aqueous-injection HPLC-MS/MS revealed high percentage detections of pharmaceuticals (110 total analytes) in surface-water and groundwater samples. The results demonstrate the importance of effluent discharge as a driver of local hydrologic conditions in an effluent-impacted stream and thus as a fundamental control on surface-water to groundwater transport of effluent-derived pharmaceutical contaminants.

Contamination of optical surfaces in Earth orbit

NASA Technical Reports Server (NTRS)

Kinser, Donald L.; Weller, Robert A.; Mendenhall, M. H.; Wiedlocher, D. E.; Nichols, R.; Tucker, D.; Whitaker, A.

1992-01-01

Glass and glass ceramic samples exposed to the low earth orbit environment for approximately 5.5 years on the Long Duration Exposure Facility (LDEF) were found to display limited degradation in optical transmission. Commercial optical quality fused silica samples display decreases in transmission in the 200 to 400 nm wavelength region, and this degradation appears to be a consequence of surface contamination. The contamination, found only on internal surfaces of samples, was measured by medium energy backscattering spectrometry and found to be primarily carbon. Additional thin film contamination by a species with atomic mass near 64, which was present at the level of about 8 x 10 exp 14/sq. cm has not been identified. These observations are consistent with the interpretation that organic binders used in the black absorbing paint (Chem Glaze Z-306) inside the sample holding tray were concentrated in the vicinity of the samples and photolytically cracked by solar UV radiation. The resulting decomposition products were deposited on the interior sample surface and gave rise to the optical transmission loss. No detectable contamination was observed on the external or space exposed surface of the samples. No measurable damage was detected which could be attributed to the direct action of gamma or UV radiation on the glass samples. These results emphasize the need for special precautions in the preparation of spacecraft carrying precision optical components on long duration missions.

Classification of fecal contamination on leafy greens by hyperspectral imaging

NASA Astrophysics Data System (ADS)

Yang, Chun-Chieh; Jun, Won; Kim, Moon S.; Chao, Kaunglin; Kang, Sukwon; Chan, Diane E.; Lefcourt, Alan

2010-04-01

This paper reported the development of hyperspectral fluorescence imaging system using ultraviolet-A excitation (320-400 nm) for detection of bovine fecal contaminants on the abaxial and adaxial surfaces of romaine lettuce and baby spinach leaves. Six spots of fecal contamination were applied to each of 40 lettuce and 40 spinach leaves. In this study, the wavebands at 666 nm and 680 nm were selected by the correlation analysis. The two-band ratio, 666 nm / 680 nm, of fluorescence intensity was used to differentiate the contaminated spots from uncontaminated leaf area. The proposed method could accurately detect all of the contaminated spots.

Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1999-06-01

The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detectionmore » level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites.« less

Evaluation of Three Swabbing Devices for Detection of Listeria monocytogenes on Different Types of Food Contact Surfaces

PubMed Central

Lahou, Evy; Uyttendaele, Mieke

2014-01-01

Listeria monocytogenes can adhere to different types of food contact surfaces within a food processing environment. Therefore, environmental sampling devices should be capable of detecting unacceptable contamination. In this study, a sponge-stick, foam spatula and an environmental swab were evaluated on their ability to detect low concentrations of L. monocytogenes on different types of food contact surfaces. A cocktail of four L. monocytogenes serotypes was inoculated with a concentration of 100 CFU/250 cm2 onto stainless steel (SS), high density polyethylene (HDPE) and rubber surfaces in a 250 cm2 area. Immediately after inoculation and after 1 h exposure, the surfaces were swabbed with the different swabbing devices. The results of the study show only minor differences in the ability of the swabbing devices to detect L. monocytogenes. All devices were capable to detect the contamination immediately after inoculation. However, when the surfaces were allowed to air-dry for 1 h, L. monocytogenes was undetected in 11.1% of the samples (n = 27) with the sponge stick, in 7.4% of the samples (n = 27) with the foam spatula and in 3.7% of the samples (n = 27) with the environmental swab, especially on SS surfaces. The detection ability of the different devices for L. monocytogenes can be concluded to be rather high on different types of food contact surfaces. PMID:24406663

Spectral unmixing of agents on surfaces for the Joint Contaminated Surface Detector (JCSD)

NASA Astrophysics Data System (ADS)

Slamani, Mohamed-Adel; Chyba, Thomas H.; LaValley, Howard; Emge, Darren

2007-09-01

ITT Corporation, Advanced Engineering and Sciences Division, is currently developing the Joint Contaminated Surface Detector (JCSD) technology under an Advanced Concept Technology Demonstration (ACTD) managed jointly by the U.S. Army Research, Development, and Engineering Command (RDECOM) and the Joint Project Manager for Nuclear, Biological, and Chemical Contamination Avoidance for incorporation on the Army's future reconnaissance vehicles. This paper describes the design of the chemical agent identification (ID) algorithm associated with JCSD. The algorithm detects target chemicals mixed with surface and interferent signatures. Simulated data sets were generated from real instrument measurements to support a matrix of parameters based on a Design Of Experiments approach (DOE). Decisions based on receiver operating characteristics (ROC) curves and area-under-the-curve (AUC) measures were used to down-select between several ID algorithms. Results from top performing algorithms were then combined via a fusion approach to converge towards optimum rates of detections and false alarms. This paper describes the process associated with the algorithm design and provides an illustrating example.

Detection of biological contaminants on foods and food surfaces using laser-induced breakdown spectroscopy (LIBS).

PubMed

Multari, Rosalie A; Cremers, David A; Dupre, Jo Anne M; Gustafson, John E

2013-09-11

The rapid detection of biological contaminants, such as Escherichia coli O157:H7 and Salmonella enterica , on foods and food-processing surfaces is important to ensure food safety and streamline the food-monitoring process. Laser-induced breakdown spectroscopy (LIBS) is an ideal candidate technology for this application because sample preparation is minimal and results are available rapidly (seconds to minutes). Here, multivariate regression analysis of LIBS data is used to differentiate the live bacterial pathogens E. coli O157:H7 and S. enterica on various foods (eggshell, milk, bologna, ground beef, chicken, and lettuce) and surfaces (metal drain strainer and cutting board). The type (E. coli or S. enterica) of bacteria could be differentiated in all cases studied along with the metabolic state (viable or heat killed). This study provides data showing the potential of LIBS for the rapid identification of biological contaminants using spectra collected directly from foods and surfaces.

Rapid Detection of Nivalenol and Deoxynivalenol in Wheat Using Surface Plasmon Resonance Immunoassay

USDA-ARS?s Scientific Manuscript database

Surface plasmon resonance immunoassay using a monoclonal antibody was developed to measure nivalenol (NIV) and deoxynivalenol (DON) contamination in wheat. A DON-immobilized sensor chip having high sensitivity and stability was prepared, and an SPR detection procedure was developed. The competitiv...

The detection of blood on dental surgery surfaces and equipment following dental hygiene treatment.

PubMed

McColl, E; Bagg, J; Winning, S

1994-01-22

The Kastle-Meyer technique, a forensic test for blood, has been employed to assess the frequency and potential routes of contamination by blood between patients, staff and equipment during routine dental hygiene treatment. Fifty treatment sessions were studied and units were cleaned between patients according to the current hospital protocol. The surfaces most frequently contaminated after treatment were the 3-in-1 syringe buttons (40%), protective bibs (22%), tap handles (20%), light handles (18%) and operating cart handles (16%). Following cleaning of the units, the surfaces remaining contaminated were the 3-in-1 syringes (10%), tap handles (4%) and cart handles (2%). Modifications to the cross-infection control protocol have been made to eliminate these sources of contamination.

Water-Quality Assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas--Surface-Water Quality, Shallow Ground-Water Quality, and Factors Affecting Water Quality in the Rincon Valley, South-Central New Mexico, 1994-95

USGS Publications Warehouse

Anderholm, Scott K.

2002-01-01

As part of the National Water-Quality Assessment Program, surface-water and ground-water samples were collected in 1994 and 1995 for analysis of common constituents, nutrients, dissolved organic carbon, trace elements, radioactivity, volatile organic compounds, and pesticides to characterize surface- water quality and shallow ground-water quality and to determine factors affecting water quality in the Rincon Valley, south-central New Mexico. Samples of surface water were collected from three sites on the Rio Grande and from sites on three agricultural drains in the Rincon Valley in January 1994 and 1995, April 1994, and October 1994. Ground-water samples were collected in late April and early May 1994 from 30 shallow wells that were installed during the investigation. Dissolved-solids concentrations in surface water ranged from 434 to 1,510 milligrams per liter (mg/L). Dissolved-solids concentrations were smallest in water from the Rio Grande below Caballo Dam and largest in the drains. Nitrite plus nitrate concentrations ranged from less than 0.05 to 3.3 mg/L as nitrogen, and ammonia concentrations ranged from less than 0.015 to 0.33 mg/L as nitrogen in surface-water samples. Trace-element concentrations in surface water were significantly smaller than the acute-fisheries standards. One or more pesticides were detected in 34 of 37 surface-water samples. DCPA (dacthal) and metolachlor were the most commonly detected pesticides. No standards have been established for the pesticides analyzed for in this study. Dissolved-solids concentrations in shallow ground water ranged from 481 to 3,630 mg/L. All but 2 of 30 samples exceeded the secondary maximum contaminant level for dissolved solids of 500 mg/L. Water from about 73 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for sulfate, and water from about 7 percent of the wells sampled exceeded the secondary maximum contaminant level of 250 mg/L for chloride. Nitrite plus nitrate concentrations ranged from less than 0.05 to 33 mg/L as nitrogen in shallow ground water. Water from about 17 percent of the well samples exceeded the maximum contaminant level of 10 mg/L as nitrogen for nitrite plus nitrate. Trace-element concentrations in shallow ground water generally were small (1 to 10 micrograms per liter). The proposed maximum contaminant level of 20 micrograms per liter for uranium was exceeded in about 13 percent of the samples. The secondary maximum contaminant level of 300 micrograms per liter for iron was exceeded in about 17 percent of the samples and of 50 micrograms per liter for manganese was exceeded in about 83 percent of the samples. Samples from about 23 percent of the wells exceeded the maximum contaminant level of 15 picocuries per liter for gross alpha activity. One or more pesticides were detected in water from 12 of 30 wells sampled. The pesticides or pesticide metabolites diazinon, metolachlor, napropamide, p,p'-DDE, and prometon were detected in one or more samples. Metolachlor and prometon were the most commonly detected pesticides. Health advisories for the pesticides detected in shallow ground water (no maximum contaminant levels have been established for the pesticides detected) are 10 to 300 times larger than the concentrations detected. Infiltration, evaporation, and transpiration of irrigation water are important factors affecting the concentrations of common constituents in shallow ground water in the Rincon Valley. Dissolution and precipitation of minerals and mixing of shallow ground water and inflow of ground water from adjacent areas also affect the composition of shallow ground water and water in the drains. Relatively large nitrite plus nitrate concentrations in several shallow ground-water samples indicate leaching of fertilizers in some areas of th

Subsurface Contamination Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Y. Yuan

There are two objectives of this report, ''Subsurface Contamination Control''. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second is to provide an evaluation of the magnitude of potential releases from a defective WP and the detectability of the released contents. The technical basis for deriving LRCL has been established in ''Retrieval Equipment and Strategy for Wp on Pallet'' (CRWMS M and O 2000g, 6.3.1). This report updates the derivation by incorporating the latest design information of themore » subsurface repository for site recommendation. The derived LRCL on the external surface of WPs, therefore, supercede that described in CRWMS M and O 2000g. The derived LRCL represent the average concentrations of contamination on the external surfaces of each WP that must not be exceeded before the WP is to be transported to the subsurface facility for emplacement. The evaluation of potential releases is necessary to control the potential contamination of the subsurface repository and to detect prematurely failed WPs. The detection of failed WPs is required in order to provide reasonable assurance that the integrity of each WP is intact prior to MGR closure. An emplaced WP may become breached due to manufacturing defects or improper weld combined with failure to detect the defect, by corrosion, or by mechanical penetration due to accidents or rockfall conditions. The breached WP may release its gaseous and volatile radionuclide content to the subsurface environment and result in contaminating the subsurface facility. The scope of this analysis is limited to radioactive contaminants resulting from breached WPs during the preclosure period of the subsurface repository. This report: (1) documents a method for deriving LRCL on the external surfaces of WP for acceptance into the subsurface repository; (2) provides a table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.« less

Screening for Groundwater Contaminants Discharging to Urban Streams

NASA Astrophysics Data System (ADS)

Roy, J. W.; Bickerton, G.; Voralek, J.

2009-05-01

Groundwater contaminated with urban pollutants can adversely affect freshwater aquatic ecosystems where it discharges to streams, lakes or wetlands. Generally such occurrences have been revealed following the discovery of contaminated groundwater plumes at a particular site or from wells in the area. Thus, this contaminant pathway tends to be dealt with on a site-specific and aquifer-focused basis. In contrast, surface water contaminant monitoring typically relies on bulk water concentrations from one or a small set of locations, thus ignoring the spatial variation in contaminant loading, potential losses to sediment or the atmosphere, and the full range of benthic components of the aquatic ecosystem. There are few studies outlining the extent of this contamination from the perspective of the surface water body's deeper benthic community, which might be expected to experience the greatest contaminant concentrations, on more than a local-scale. In this study, we report on an approach to stream-reach-screening for urban contaminants in discharging groundwater, with the focus on detection rather than accurate quantification. The methodology consists of a drive-point technique for sampling groundwater from below the stream bed (e.g. typically 50 cm) along a chosen reach at intervals of about 10 m. Groundwater samples were then analyzed for a wide range of common urban contaminants and general chemistry. This screening method was performed in three urban settings in Canada with known groundwater contamination, covering sections of about 140 to >500 m. The known contaminant plumes at each site were detected and roughly delineated. In addition, potential areas of previously-unknown groundwater contamination were also identified at each site. Contaminants included BTEX and other petroleum hydrocarbons, various chlorinated solvent compounds, nitrate, 1,4-dioxane, MTBE and elevated chloride (likely indicating road salt). These preliminary findings suggest that this approach may be useful for quickly assessing the cumulative threat to aquatic ecosystems of potentially multiple groundwater contaminant sources discharging to surface water bodies in urban settings.

Widespread occurrence and potential for biodegradation of bioactive contaminants in Congaree National Park, USA

USGS Publications Warehouse

Bradley, Paul M.; Battaglin, William A.; Clark, Jimmy M.; Henning, Frank; Hladik, Michelle L.; Iwanowicz, Luke R.; Journey, Celeste A.; Riley, Jeffrey W.; Romanok, Kristin

2017-01-01

Organic contaminants with designed molecular bioactivity, such as pesticides and pharmaceuticals, originate from human and agricultural sources, occur frequently in surface waters, and threaten the structure and function of aquatic and terrestrial ecosystems. Congaree National Park in South Carolina (USA) is a vulnerable park unit due to its location downstream of multiple urban and agricultural contaminant sources and its hydrologic setting, being composed almost entirely of floodplain and aquatic environments. Seventy-two water and sediment samples were collected from 16 sites in Congaree National Park during 2013 to 2015, and analyzed for 199 and 81 targeted organic contaminants, respectively. More than half of these water and sediment analytes were not detected or potentially had natural sources. Pharmaceutical contaminants were detected (49 total) frequently in water throughout Congaree National Park, with higher detection frequencies and concentrations at Congaree and Wateree River sites, downstream from major urban areas. Forty-seven organic wastewater indicator chemicals were detected in water, and 36 were detected in sediment, of which approximately half are distinctly anthropogenic. Endogenous sterols and hormones, which may originate from humans or wildlife, were detected in water and sediment samples throughout Congaree National Park, but synthetic hormones were detected only once, suggesting a comparatively low risk of adverse impacts. Assessment of the biodegradation potentials of 8 14C-radiolabeled model contaminants indicated poor potentials for some contaminants, particularly under anaerobic sediments conditions.

X-ray fluorescence surface contaminant analyzer: A feasibility study

NASA Technical Reports Server (NTRS)

Eldridge, Hudson B.

1988-01-01

The bonding of liner material to the inner metal surfaces of solid rocket booster cases is adversely affected by minute amounts of impurities on the metal surface. Suitable non-destructive methods currently used for detecting these surface contaminants do not provide the means of identifying their elemental composition. The feasibility of using isotopic source excited energy dispersive X-ray fluorescence as a possible technique for elemental analysis of such contaminants is investigated. A survey is made of the elemental compositions of both D-6ac steel, a common construction material for the booster cases, and Conoco HD-2 grease, a common surface contamination. Source and detector choices that maximize signal to noise ratio in a Recessed Source Geometry are made. A Monte Carlo simulation is then made of the optimized device incorporating the latest available X-ray constants at the energy of the chosen source to determine the device's response to a D-6ac steel surface contained with Conoco HD-2 grease.

1,4-Dioxane drinking water occurrence data from the third unregulated contaminant monitoring rule.

PubMed

Adamson, David T; Piña, Elizabeth A; Cartwright, Abigail E; Rauch, Sharon R; Hunter Anderson, R; Mohr, Thomas; Connor, John A

2017-10-15

This study examined data collected from U.S. public drinking water supplies in support of the recently-completed third round of the Unregulated Contaminant Monitoring Rule (UCMR3) to better understand the nature and occurrence of 1,4-dioxane and the basis for establishing drinking water standards. The purpose was to evaluate whether the occurrence data for this emerging but federally-unregulated contaminant fit with common conceptual models, including its persistence and the importance of groundwater contamination for potential exposure. 1,4-Dioxane was detected in samples from 21% of 4864 PWSs, and was in exceedance of the health-based reference concentration (0.35μg/L) at 6.9% of these systems. In both measures, it ranked second among the 28 UCMR3 contaminants. Although much of the focus on 1,4-dioxane has been its role as a groundwater contaminant, the detection frequency for 1,4-dioxane in surface water was only marginally lower than in groundwater (by a factor of 1.25; p<0.0001). However, groundwater concentrations were higher than those in surface water (p<0.0001) and contributed to a higher frequency of exceeding the reference concentration (by a factor of 1.8, p<0.0001), indicating that surface water sources tend to be more dilute. Sampling from large systems increased the likelihood that 1,4-dioxane was detected by a factor of 2.18 times relative to small systems (p<0.0001). 1,4-Dioxane detections in drinking water were highly associated with detections of other chlorinated compounds particularly 1,1-dichlorethane (odds ratio=47; p<0.0001), which is associated with the release of 1,4-dioxane as a chlorinated solvent stabilizer. Based on aggregated nationwide data, 1,4-dioxane showed evidence of a decreasing trend in concentration and detection frequency over time. These data suggest that the loading to drinking water supplies may be decreasing. However, in the interim, some water supply systems may need to consider improving their treatment capabilities in response to further regulatory review of this compound. Copyright © 2017 Elsevier B.V. All rights reserved.

Mie Scattering of Growing Molecular Contaminants

NASA Technical Reports Server (NTRS)

Herren, Kenneth A.; Gregory, Don A.

2007-01-01

Molecular contamination of optical surfaces from outgassed material has been shown in many cases to proceed from acclimation centers and to produce many roughly hemispherical "islands" of contamination on the surface. The mathematics of the hemispherical scattering is simplified by introducing a Virtual source below the plane of the optic, in this case a mirror, allowing the use of Mie theory to produce a solution for the resulting sphere .in transmission. Experimentally, a fixed wavelength in the vacuum ultraviolet was used as the illumination source and scattered light from the polished and coated glass mirrors was detected at a fixed angle as the contamination islands grew in time.

Occurrence of herbicides and pharmaceutical and personal care products in surface water and groundwater around Liberty Bay, Puget Sound, Washington

USGS Publications Warehouse

Dougherty, Jennifer A.; Swarzenski, Peter W.; Dinicola, Richard S.; Reinhard, Martin

2010-01-01

Organic contaminants, such as pharmaceuticals and personal care products (PPCPs), pose a risk to water quality and the health of ecosystems. This study was designed to determine if a coastal community lacking point sources, such as waste water treatment plant effluent, could release PPCPs, herbicides, and plasticizers at detectable levels to their surface water and groundwater. Research was conducted in Liberty Bay, an embayment within Puget Sound, where 70% of the population (∼10,000) uses septic systems. Sampling included collection of groundwater and surface water with grab samples and the use of polar organic chemical integrative samplers (POCIS). We analyzed for a broad spectrum of 25 commonly used compounds, including PPCPs, herbicides, and a flame retardant. Twelve contaminants were detected at least once; only N,N-diethyl-meta-toluamide, caffeine, and mecoprop, a herbicide not attributed to septic systems, were detected in more than one grab sample. The use of POCIS was essential because contaminants were present at very low levels (nanograms), which is common for PPCPs in general, but particularly so in such a small community. The use of POCIS allowed the detection of five compounds that were not present in grab samples. Data suggest that the community is contaminating local water with PPCPs; this effect is likely to increase as the population and product usage increase. The results presented here are a first step toward assessing the transport of herbicides and PPCPs into this coastal system.

Occurrence of herbicides and pharmaceutical and personal care products in surface water and groundwater around Liberty Bay, Puget Sound, Washington.

PubMed

Dougherty, Jennifer A; Swarzenski, Peter W; Dinicola, Richard S; Reinhard, Martin

2010-01-01

Organic contaminants, such as pharmaceuticals and personal care products (PPCPs), pose a risk to water quality and the health of ecosystems. This study was designed to determine if a coastal community lacking point sources, such as waste water treatment plant effluent, could release PPCPs, herbicides, and plasticizers at detectable levels to their surface water and groundwater. Research was conducted in Liberty Bay, an embayment within Puget Sound, where 70% of the population (-10,000) uses septic systems. Sampling included collection of groundwater and surface water with grab samples and the use of polar organic chemical integrative samplers (POCIS). We analyzed for a broad spectrum of 25 commonly used compounds, including PPCPs, herbicides, and a flame retardant. Twelve contaminants were detected at least once; only N,N-diethyl-meta-toluamide, caffeine, and mecoprop, a herbicide not attributed to septic systems, were detected in more than one grab sample. The use of POCIS was essential because contaminants were present at very low levels (nanograms), which is common for PPCPs in general, but particularly so in such a small community. The use of POCIS allowed the detection of five compounds that were not present in grab samples. Data suggest that the community is contaminating local water with PPCPs; this effect is likely to increase as the population and product usage increase. The results presented here are a first step toward assessing the transport of herbicides and PPCPs into this coastal system.

Occupational Exposure to Chemotherapy of Pharmacy Personnel at a Single Centre

PubMed Central

Ramphal, Raveena; Bains, Tejinder; Goulet, Geneviève; Vaillancourt, Régis

2015-01-01

Background: Cyclophosphamide is one of the most commonly used chemotherapy drugs worldwide. Data concerning environmental contamination and biological exposure of pharmacy personnel to this and other chemotherapy drugs are limited. Objectives: To determine whether pharmacy personnel involved in preparing and checking cyclophosphamide doses were more likely to have detectable levels of this drug in their urine than non-oncology pharmacy personnel with no known contact with the drug, and to compare the degree of surface contamination with cyclophosphamide, methotrexate, and ifosfamide in the oncology pharmacy of a tertiary care pediatric hospital, where chemotherapy doses were prepared, and the main (control) pharmacy in the same institution, where no chemotherapy was prepared. Methods: Biological exposure to cyclophosphamide was compared between pharmacy personnel who did and did not handle this drug by determining whether participants had detectable amounts of cyclophosphamide in their urine. Environmental exposure to chemotherapy drugs was assessed by using surface wipes to determine the degree of surface contamination with various chemotherapy agents in the oncology pharmacy and the main (control) pharmacy. Results: On initial testing, cyclophosphamide was detected in the urine of all pharmacy personnel (n = 7 oncology personnel, n = 5 control personnel). However, it was determined that all control personnel had been exposed to the oncology pharmacy on the day of testing. Repeat testing of these individuals revealed no positive samples among those not exposed to the oncology pharmacy on the day of repeat testing. The sole positive result on retesting of control personnel was for a participant who had been exposed to the oncology pharmacy on the retest day. Surface wipe testing revealed contamination of the oncology pharmacy with cyclophosphamide and methotrexate before and after cleaning, as well as contamination with ifosfamide after cleaning. The main (control) pharmacy showed no evidence of contamination with cyclophosphamide, methotrexate, or ifosfamide. Conclusions: The findings suggest that environmental contamination plays a role in biological exposure to cyclophosphamide. Measures to reduce environmental contamination from chemotherapy and biological exposure of pharmacy personnel when handling chemotherapy agents should be identified and implemented as a priority. PMID:25964681

Hydrochemical profiles in urban groundwater systems: New insights into contaminant sources and pathways in the subsurface from legacy and emerging contaminants.

PubMed

White, D; Lapworth, D J; Stuart, M E; Williams, P J

2016-08-15

It has long been known that groundwaters beneath urban areas carry a fingerprint from urban activities but finding a consistent tracer for anthropogenic influence has proved elusive. The varied sources of urban contaminants means that a single consistent and inexpensive means of tracing the fate of urban contaminants is not generally possible and multiple tracers are often required to understand the contaminant sources and pathways in these complex systems. This study has utilized a combination of micro-organic (MO) contaminants and inorganic hydrochemistry to trace recharge pathways and quantify the variability of groundwater quality in multi-level piezometers in the city of Doncaster, UK. A total of 23 MOs were detected during this study, with more compounds consistently detected during higher groundwater table conditions highlighting the importance of sampling under different hydrological conditions. Four of the compounds detected are EU Water Framework Directive priority substances: atrazine, simazine, naphthalene and DEHP, with a maximum concentration of 0.18, 0.03, 0.2, 16μg/l respectively. Our study shows that the burden of the banned pesticide atrazine persists in the Sherwood Sandstone and is detected at two of the three study sites. Emerging contaminants are seen throughout the borehole profiles and provide insights into transient pathways for contaminant migration in the sub-surface. Long term changes in inorganic hydrochemistry show possible changes in contaminant input or the dissolution of minerals. Nitrate was detected above 50mg/l but on the whole nitrate concentrations have declined in the intervening years either due to a reduction of nitrate application at the surface or a migration of peak nitrate concentrations laterally or to greater depth. This study shows that multiple tracers together with multi-level piezometers can give a better resolution of contaminant pathways and variable flow regimes within the relatively uncomplicated aquifer of the Sherwood Sandstone compared with single long screened wells. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

An Immunoassay for Quantification of Contamination by Raw Meat Juice on Food Contact Surfaces.

PubMed

Chen, Fur-Chi; Godwin, Sandria; Chambers, Edgar

2016-11-01

Raw chicken products often are contaminated with Salmonella and Campylobacter , which can be transmitted from packages to contact surfaces. Raw meat juices from these packages also provide potential media for cross-contamination. There are limited quantitative data on the levels of consumer exposure to raw meat juice during shopping for and handling of chicken products. An exposure assessment is needed to quantify the levels of transmission and to assess the risk. An enzyme-linked immunosorbent assay (ELISA) was developed and validated for quantitative detection of raw meat juice on hands and various food contact surfaces. Analytical procedures were designed to maximize the recovery of raw meat juice from various surfaces: hands, plastic, wood, stainless steel, laminated countertops, glass, and ceramics. The ELISA was based on the detection of a soluble muscle protein, troponin I (TnI), in the raw meat juice. The assay can detect levels as low as 1.25 ng of TnI, which is equivalent to less than 1 μl of the raw meat juice. The concentrations of TnI in the raw meat juices from 10 retail chicken packages, as determined by ELISA, were between 0.46 and 3.56 ng/μl, with an average of 1.69 ng/μl. The analytical procedures, which include swabbing, extraction, and concentration, enable the detection of TnI from various surfaces. The recoveries of raw meat juice from surfaces of hands were 92%, and recoveries from other tested surfaces were from 55% on plastic cutting boards to 75% on laminated countertops. The ELISA developed has been used for monitoring the transfer of raw meat juice during shopping for and handling of raw chicken products in our studies. The assay also can be applied to other raw meat products, such as pork and beef.

Nationwide reconnaissance of contaminants of emerging ...

EPA Pesticide Factsheets

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To this end, source and treated drinking water samples from 29 drinking water treatment plants (DWTPs) were analyzed as part of a two-phase study to determine whether chemical and microbial constituents, many of which are considered contaminants of emerging concern, were detectable in the waters. Of the 84 chemicals monitored in the 9 Phase I DWTPs, 27 were detected at least once in the source water, and 21 were detected at least once in treated drinking water. In Phase II, which was a broader and more comprehensive assessment, 247 chemical and microbial analytes were measured in 25 DWTPs, with 148 detected at least once in the source water, and 121 detected at least once in the treated drinking water. The frequency of detection was often related to the analyte's contaminant class, as pharmaceuticals and anthropogenic waste indicators tended to be infrequently detected and more easily removed during treatment, while per and polyfluoroalkyl substances and inorganic constituents were both more frequently detected and, overall, more resistant to treatment. The data collected as part of this project will be used to help inform evaluation of unregulated contaminants in surface water, groundwate

Chlamydia and gonorrhoea contamination of clinic surfaces.

PubMed

Lewis, Natasha; Dube, Gail; Carter, Christine; Pitt, Rachel; Alexander, Sarah; Ison, Catherine A; Harding, Jan; Brown, Louise; Fryer, John; Hodson, James; Ross, Jonathan

2012-10-01

Nucleic acid amplification tests, with their ability to detect very small amounts of nucleic acid, have become the principle diagnostic tests for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) in many sexual health clinics. The aim of this study was to investigate the extent of surface contamination with CT and GC within a city centre sexual health clinic and to evaluate the potential for contamination of containers used for the collection of self-taken swabs. Surface contamination with CT and GC was assessed by systematically sampling 154 different sites within one clinic using transcription-mediated amplification (TMA), quantitative PCR and culture. The caps of containers used by patients to collect self-taken samples were also tested for CT and GC using TMA. Of the 154 sites sampled, 20 (13.0%) tested positive on TMA. Of these, five (3.2%) were positive for CT alone, 11 (7.1%) for GC alone and four (2.6%) for both CT and GC. The proportion of GC TMA-positive test results differed by gender, with 11 (18.3%) positive results from the male patient clinic area compared with one (1.6%) from the female area (p=0.002). Positive samples were obtained from a variety of locations in the clinic, but the patient toilets were more likely to be contaminated than examination rooms (p=0.015). Quantitative PCR and culture assays were negative for all samples. 46 caps of the containers used for self-taken swabs were negative for both CT and GC on TMA testing. Surface contamination with chlamydial and gonococcal rRNA can occur within sexual health clinics, but the quantity of nucleic acid detected is low and infection risk to patients and staff is small. There remains a potential risk of contamination of patient samples leading to false-positive results.

Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites.

PubMed

Kurashige, E Jessica Ohashi; Oie, Shigeharu; Furukawa, H

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7-14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4cm×8cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0-255)colony-forming units (cfu)/100cm(2), respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0-1620)cfu/100cm(2), respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary. Copyright © 2016. Published by Elsevier Editora Ltda.

Analysis of particulate contamination on tape lift samples from the VETA optical surfaces

NASA Technical Reports Server (NTRS)

Germani, Mark S.

1992-01-01

Particulate contamination analysis was carried out on samples taken from the Verification Engineering Test Article (VETA) x-ray detection system. A total of eighteen tape lift samples were taken from the VETA optical surfaces. Initially, the samples were tested using a scanning electron microscope. Additionally, particle composition was determined by energy dispersive x-ray spectrometry. Results are presented in terms of particle loading per sample.

Sensing of contaminants in potable water using TiO{sub 2} functional film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akshatha, N.; Poonia, Monika; Gupta, R. K., E-mail: raj@pilani.bits-pilani.ac.in

2016-04-13

The piezoelectric based quartz crystal microbalance is employed for sensing contaminants in potable water. A spin coated thin layer of TiO{sub 2} nanoparticles was formed at the sensing area of a 5 MHz AT-cut quartz wafer. The thin film of TiO{sub 2} nanoparticles forms a mesoporous functional layer for the trapping of water borne contaminants. The morphology of the thin film of TiO{sub 2} nanoparticles was studied using field emission scanning electron microscope (FESEM). The surface morphology of the TiO{sub 2} nanoparticles reveals the mesoporous structures indicating large number of defects and porous sites. Such film was employed for the detectionmore » of water borne contaminants by detecting the piezoelectric response from a quartz crystal microbalance. We found the film to be very sensitive to the contaminants. The minimum detection limit was found to be 330 ppb. The effect of surface recharging was also studied by altering the physical conditions so that the film can be used for repetitive usage.« less

QCL-based standoff and proximal chemical detectors

NASA Astrophysics Data System (ADS)

Dupuis, Julia R.; Hensley, Joel; Cosofret, Bogdan R.; Konno, Daisei; Mulhall, Phillip; Schmit, Thomas; Chang, Shing; Allen, Mark; Marinelli, William J.

2016-05-01

The development of two longwave infrared quantum cascade laser (QCL) based surface contaminant detection platforms supporting government programs will be discussed. The detection platforms utilize reflectance spectroscopy with application to optically thick and thin materials including solid and liquid phase chemical warfare agents, toxic industrial chemicals and materials, and explosives. Operation at standoff (10s of m) and proximal (1 m) ranges will be reviewed with consideration given to the spectral signatures contained in the specular and diffusely reflected components of the signal. The platforms comprise two variants: Variant 1 employs a spectrally tunable QCL source with a broadband imaging detector, and Variant 2 employs an ensemble of broadband QCLs with a spectrally selective detector. Each variant employs a version of the Adaptive Cosine Estimator for detection and discrimination in high clutter environments. Detection limits of 5 μg/cm2 have been achieved through speckle reduction methods enabling detector noise limited performance. Design considerations for QCL-based standoff and proximal surface contaminant detectors are discussed with specific emphasis on speckle-mitigated and detector noise limited performance sufficient for accurate detection and discrimination regardless of the surface coverage morphology or underlying surface reflectivity. Prototype sensors and developmental test results will be reviewed for a range of application scenarios. Future development and transition plans for the QCL-based surface detector platforms are discussed.

Surface-enhanced Raman detection of CW agents in water using gold sol gel substrates

NASA Astrophysics Data System (ADS)

Premasiri, W. Ranjith; Clarke, Richard H.; Womble, M. Edward

2002-02-01

The development of a water analysis system capable of detecting both inanimate trace chemical contaminants and viable microbial contaminants has long been a project of interest to our group. The capability of detecting both chemical and biological agent sources in a single device configuration would clearly add to the value of such a product. In the present work, we describe results with chemical warfare agents from our efforts to produce a Raman system for the detection of both chemical and biological warfare agents in water. We utilize laser Raman light scattering and employ Surface Enhanced Raman Spectroscopy (SERS)on solid state gold sol-gel detectors combined with fiber optic collection of the enhanced light signal in the sampling system to augment the normally low intensity Raman Scattering signal from trace materials.

Method for the Collection, Gravimetric and Chemical Analysis of Nonvolatile Residue (NVR) on Surfaces

NASA Technical Reports Server (NTRS)

Gordon, Keith; Rutherford, Gugu; Aranda, Denisse

2017-01-01

Nonvolatile residue (NVR), sometimes referred to as molecular contamination is the term used for the total composition of the inorganic and high boiling point organic components in particulates and molecular films deposited on critical surfaces surrounding space structures, with the particulate and NVR contamination originating primarily from pre-launch operations. The "nonvolatile" suggestion from the terminology NVR implies that the collected residue will not experience much loss under ambient conditions. NVR has been shown to have a dramatic impact on the ability to perform optical measurements from platforms based in space. Such contaminants can be detected early by the controlled application of various detection techniques and contamination analyses. Contamination analyses are the techniques used to determine if materials, components, and subsystems can be expected to meet the performance requirements of a system. Of particular concern is the quantity of NVR contaminants that might be deposited on critical payload surfaces from these sources. Subsequent chemical analysis of the contaminant samples by infrared spectroscopy and gas chromatography mass spectrometry identifies the components, gives semi-quantitative estimates of contaminant thickness, indicates possible sources of the NVR, and provides guidance for effective cleanup procedures. In this report, a method for the collection and determination of the mass of NVR was generated by the authors at NASA Langley Research Center. This report describes the method developed and implemented for collecting NVR contaminants, and procedures for gravimetric and chemical analysis of the residue obtained. The result of this NVR analysis collaboration will help pave the way for Langley's ability to certify flight hardware outgassing requirements in support of flight projects such as Stratospheric Aerosol and Gas Experiment III (SAGE III), Clouds and the Earth's Radiant Energy System (CERES), Materials International Space Station Experiment - X (MISSE-X), and Doppler Aerosol Wind Lidar (DAWN).

Surface microbial contamination in hospitals: A pilot study on methods of sampling and the use of proposed microbiologic standards.

PubMed

Claro, Tânia; O'Reilly, Marese; Daniels, Stephen; Humphreys, Hilary

2015-09-01

Contamination of hospital surfaces by bacteria is increasingly recognized. We assessed commonly touched surfaces using contact plates and Petrifilms (3M, St. Paul, MN) and compared the results against proposed microbiology standards. Toilet door handles were the most heavily contaminated (7.97 ± 0.68 colony forming units [CFU]/cm(2)) and exceeded proposed standards on 74% of occasions. Petrifilms detected statistically higher CFU from bedside lockers. Further research is required on the use of standards and methods of sampling. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Phenolic contamination in the sand-and-gravel aquifer from a surface impoundment of wood treatment wastes, Pensacola, Florida

USGS Publications Warehouse

Troutman, D.E.; Godsy, E.M.; Goerlitz, D.F.; Ehrlich, G.G.

1984-01-01

Creosote and pentachlorophenol wastewaters discharged to unlined surface impoundments have resulted in groundwater contamination in the vicinity of an industrial site near Pensacola, Florida. Total phenol concentrations of 36,000 microgm/liter have been detected 40 ft below land surface in a test hole 100 ft south of an overflow impoundment but less than 10 microgm/liter 90 ft below land surface. Samples collected in test holes 1,350 ft downgradient from the surface impoundments and 100 ft north of Pensacola Bay, above and immediately below a clay lens, indicate that phenol contaminated groundwater may not be discharging directly into Pensacola Bay. Phenol concentrations exceeding 20 microgm/liter were detected in samples from a drainage ditch discharging directly into Bayou Chico. Microbiological data collected near the test site suggest that an anaerobic methanogenic ecosystem contributes to a reduction in phenol concentrations in groundwater. A laboratory study using bacteria isolated from the study site indicates that phenol, 2-methylphenol, and 3-methylphenol are significantly degraded and that methanogenesis reduces total phenol concentrations in laboratory digestors by 45%. Pentachlorophenol may inhibit methanogenesis at concentrations exceeding 0.45 milligm/liter. (USGS)

Understanding sources of contaminants of emerging concern in a mixed use watershed

USDA-ARS?s Scientific Manuscript database

Contaminants of emerging concern (CECs) have been detected in surface waters worldwide and include biologically active compounds originating from agricultural, residential, and industrial sources that may result in potential ecological and health effects. The objectives of this research were to dete...

Internal dosimetry technical basis manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-12-20

The internal dosimetry program at the Savannah River Site (SRS) consists of radiation protection programs and activities used to detect and evaluate intakes of radioactive material by radiation workers. Examples of such programs are: air monitoring; surface contamination monitoring; personal contamination surveys; radiobioassay; and dose assessment. The objectives of the internal dosimetry program are to demonstrate that the workplace is under control and that workers are not being exposed to radioactive material, and to detect and assess inadvertent intakes in the workplace. The Savannah River Site Internal Dosimetry Technical Basis Manual (TBM) is intended to provide a technical and philosophicalmore » discussion of the radiobioassay and dose assessment aspects of the internal dosimetry program. Detailed information on air, surface, and personal contamination surveillance programs is not given in this manual except for how these programs interface with routine and special bioassay programs.« less

Preliminary Results of Cleaning Process for Lubricant Contamination

NASA Astrophysics Data System (ADS)

Eisenmann, D.; Brasche, L.; Lopez, R.

2006-03-01

Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented.

Assessment of arsenic surface contamination in a museum anthropology department.

PubMed

Gribovich, Andrey; Lacey, Steven; Franke, John; Hinkamp, David

2013-02-01

To assess potential arsenic (As) contamination of work surfaces to improve upon the control strategy at an anthropology department in a large natural history museum. Work practices were observed and control strategy reviewed to inform an occupational hygiene assessment strategy utilizing surface wipe sampling. A total of 35 sampling targets were identified, focusing on surfaces that receive high touch traffic, including workstations, artifact transport carts, and elevator buttons. Arsenic sampling and analysis were performed using reference method Occupational Safety and Health Administration ID-125G. Four of the sampling areas returned detectable levels of As, ranging from 0.052 to 0.350 μg/100 cm. Workplace observations and wipe sampling data enabled the development of recommendations to help to further reduce potential occupational exposure to As. Continuous reduction of surface contamination is prudent for known human carcinogens.

Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Lorah, Michelle M.; Clark, Jeffrey S.

1996-01-01

Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

Empirical measurement and model validation of infrared spectra of contaminated surfaces

NASA Astrophysics Data System (ADS)

Archer, Sean; Gartley, Michael; Kerekes, John; Cosofret, Bogdon; Giblin, Jay

2015-05-01

Liquid-contaminated surfaces generally require more sophisticated radiometric modeling to numerically describe surface properties. The Digital Imaging and Remote Sensing Image Generation (DIRSIG) Model utilizes radiative transfer modeling to generate synthetic imagery. Within DIRSIG, a micro-scale surface property model (microDIRSIG) was used to calculate numerical bidirectional reflectance distribution functions (BRDF) of geometric surfaces with applied concentrations of liquid contamination. Simple cases where the liquid contamination was well described by optical constants on optically at surfaces were first analytically evaluated by ray tracing and modeled within microDIRSIG. More complex combinations of surface geometry and contaminant application were then incorporated into the micro-scale model. The computed microDIRSIG BRDF outputs were used to describe surface material properties in the encompassing DIRSIG simulation. These DIRSIG generated outputs were validated with empirical measurements obtained from a Design and Prototypes (D&P) Model 102 FTIR spectrometer. Infrared spectra from the synthetic imagery and the empirical measurements were iteratively compared to identify quantitative spectral similarity between the measured data and modeled outputs. Several spectral angles between the predicted and measured emissivities differed by less than 1 degree. Synthetic radiance spectra produced from the microDIRSIG/DIRSIG combination had a RMS error of 0.21-0.81 watts/(m2-sr-μm) when compared to the D&P measurements. Results from this comparison will facilitate improved methods for identifying spectral features and detecting liquid contamination on a variety of natural surfaces.

Occurrence of organic wastewater and other contaminants in cave streams in northeastern Oklahoma and northwestern Arkansas.

PubMed

Bidwell, Joseph R; Becker, Carol; Hensley, Steve; Stark, Richard; Meyer, Michael T

2010-02-01

The prevalence of organic wastewater compounds in surface waters of the United States has been reported in a number of recent studies. In karstic areas, surface contaminants might be transported to groundwater and, ultimately, cave ecosystems, where they might impact resident biota. In this study, polar organic chemical integrative samplers (POCISs) and semipermeable membrane devices (SPMDs) were deployed in six caves and two surface-water sites located within the Ozark Plateau of northeastern Oklahoma and northwestern Arkansas in order to detect potential chemical contaminants in these systems. All caves sampled were known to contain populations of the threatened Ozark cavefish (Amblyopsis rosae). The surface-water site in Oklahoma was downstream from the outfall of a municipal wastewater treatment plant and a previous study indicated a hydrologic link between this stream and one of the caves. A total of 83 chemicals were detected in the POCIS and SPMD extracts from the surface-water and cave sites. Of these, 55 chemicals were detected in the caves. Regardless of the sampler used, more compounds were detected in the Oklahoma surface-water site than in the Arkansas site or the caves. The organic wastewater chemicals with the greatest mass measured in the sampler extracts included sterols (cholesterol and beta-sitosterol), plasticizers [diethylhexylphthalate and tris(2-butoxyethyl) phosphate], the herbicide bromacil, and the fragrance indole. Sampler extracts from most of the cave sites did not contain many wastewater contaminants, although extracts from samplers in the Oklahoma surface-water site and the cave hydrologically linked to it had similar levels of diethylhexyphthalate and common detections of carbamazapine, sulfamethoxazole, benzophenone, N-diethyl-3-methylbenzamide (DEET), and octophenol monoethoxylate. Further evaluation of this system is warranted due to potential ongoing transport of wastewater-associated chemicals into the cave. Halogenated organics found in caves and surface-water sites included brominated flame retardants, organochlorine pesticides (chlordane and nonachlor), and polychlorinated biphenyls. The placement of samplers in the caves (near the cave mouth compared to farther in the system) might have influenced the number of halogenated organics detected due to possible aerial transport of residues. Guano from cave-dwelling bats also might have been a source of some of these chlorinated organics. Seven-day survival and growth bioassays with fathead minnows (Pimephales promelas) exposed to samples of cave water indicated initial toxicity in water from two of the caves, but these effects were transient, with no toxicity observed in follow-up tests.

In situ measurements of scattering from contaminated optics in the Vacuum Ultraviolet

NASA Astrophysics Data System (ADS)

Herren, Kenneth A.; Linton, Roger C.; Whitaker, Ann F.

1990-07-01

NASA's In Situ Contamination Effects Facility has been used to measure the time dependence of the angular reflectance from molecularly contaminated optical surfaces in the vacuum ultraviolet. The light scattering measurements are accomplished in situ on optical surfaces in real time during deposition of molecular contaminants. The measurements are taken using noncoherent VUV sources with the predominant wavelengths being the krypton resonance lines at 1236 and 1600 angstroms. Detection of the scattered light is accomplished using a set of three solar blind VUV photomultipliers. An in-plane VUV BRDF (bidirectional reflectance distribution function) experiment is described and details of the on-going program to characterize optical materials exposed to the space environment is reported.

In situ measurements of scattering from contaminated optics in the Vacuum Ultraviolet

NASA Technical Reports Server (NTRS)

Herren, Kenneth A.; Linton, Roger C.; Whitaker, Ann F.

1990-01-01

NASA's In Situ Contamination Effects Facility has been used to measure the time dependence of the angular reflectance from molecularly contaminated optical surfaces in the vacuum ultraviolet. The light scattering measurements are accomplished in situ on optical surfaces in real time during deposition of molecular contaminants. The measurements are taken using noncoherent VUV sources with the predominant wavelengths being the krypton resonance lines at 1236 and 1600 angstroms. Detection of the scattered light is accomplished using a set of three solar blind VUV photomultipliers. An in-plane VUV BRDF (bidirectional reflectance distribution function) experiment is described and details of the on-going program to characterize optical materials exposed to the space environment is reported.

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

USGS Publications Warehouse

Walker, C.E.; Schrock, R.M.; Reilly, T.J.; Baehr, A.L.

2005-01-01

Groundwater under the direct influence of surface water (GWUDISW) is of concern in communities where growing public demand on groundwater resources has resulted in increased withdrawals and hydraulic stress near surface water bodies. Under these conditions, contaminants such as methyl-tert butyl ether (MTBE) and biological materials have been detected in domestic wells. Other contaminants and pathogens associated with surface water are not routinely tested for in groundwater-supplied systems. To address the need for methods to easily identify potentially vulnerable supplies, a direct immunoassay for the quantitative detection of diatoms in raw water samples was developed as a measure of surface water influence on groundwater. Cell wall preparations from Nitzschia palea Ku??tzing, a freshwater diatom found throughout North America, were used to produce a polyclonal antibody that was applied in a direct enzyme-linked immunosorbent assay (ELISA) developed to detect the presence of N. palea cell wall components. The direct immunoassay allows detection at 500 cells L-1, a level similar to diatom concentrations observed in samples of groundwater collected near the test site. This investigation was the first attempt to utilize an ELISA as an indicator of surface water influence on groundwater. Further research is needed to develop more specific diatom-based monoclonal antibodies, determine cross-reactivity, and optimize sample processing and ELISA procedures for development of a standardized method. ?? Springer 2005.

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

USGS Publications Warehouse

Walker, C.E.; Schrock, R.M.; Reilly, T.J.; Baehr, A.L.

2005-01-01

Groundwater under the direct influence of surface water (GWUDISW) is of concern in communities where growing public demand on groundwater resources has resulted in increased withdrawals and hydraulic stress near surface water bodies. Under these conditions, contaminants such as methyl-tert butyl ether (MTBE) and biological materials have been detected in domestic wells. Other contaminants and pathogens associated with surface water are not routinely tested for in groundwater-supplied systems. To address the need for methods to easily identify potentially vulnerable supplies, a direct immunoassay for the quantitative detection of diatoms in raw water samples was developed as a measure of surface water influence on groundwater. Cell wall preparations from Nitzschia palea Kützing, a freshwater diatom found throughout North America, were used to produce a polyclonal antibody that was applied in a direct enzyme-linked immunosorbent assay (ELISA) developed to detect the presence of N. palea cell wall components. The direct immunoassay allows detection at 500 cells L−1, a level similar to diatom concentrations observed in samples of groundwater collected near the test site. This investigation was the first attempt to utilize an ELISA as an indicator of surface water influence on groundwater. Further research is needed to develop more specific diatom-based monoclonal antibodies, determine cross-reactivity, and optimize sample processing and ELISA procedures for development of a standardized method.

Early-stage bioassay for monitoring radioactive contamination in living livestock.

PubMed

Yamaguchi, Toshiro; Sawano, Kaita; Kishimoto, Miori; Furuhama, Kazuhisa; Yamada, Kazutaka

2012-12-01

Soil samples from the ground surface and feces and blood from a mixed-breed male pig were collected on April 10, 2011 at a farm within 20 km of the Fukushima Daiichi nuclear power plant. The radioactivity of each sample was measured using a Ge semiconductor detector. Despite the fact that the pig had been fed non-contaminated imported feed, (131)I, (134)Cs and (137)Cs were detected in the feces, and (134)Cs and (137)Cs were detected in the blood clots. Because it is considerably difficult to measure radioactive contamination in the edible muscle of living livestock, bioassays are an option for the screening of radioactive contamination in living livestock to ensure food safety.

Toxicological relevance of emerging contaminants for drinking water quality.

PubMed

Schriks, Merijn; Heringa, Minne B; van der Kooi, Margaretha M E; de Voogt, Pim; van Wezel, Annemarie P

2010-01-01

The detection of many new compounds in surface water, groundwater and drinking water raises considerable public concern, especially when human health based guideline values are not available it is questioned if detected concentrations affect human health. In an attempt to address this question, we derived provisional drinking water guideline values for a selection of 50 emerging contaminants relevant for drinking water and the water cycle. For only 10 contaminants, statutory guideline values were available. Provisional drinking water guideline values were based upon toxicological literature data. The maximum concentration levels reported in surface waters, groundwater and/or drinking water were compared to the (provisional) guideline values of the contaminants thus obtained, and expressed as Benchmark Quotient (BQ) values. We focused on occurrence data in the downstream parts of the Rhine and Meuse river basins. The results show that for the majority of compounds a substantial margin of safety exists between the maximum concentration in surface water, groundwater and/or drinking water and the (provisional) guideline value. The present assessment therefore supports the conclusion that the majority of the compounds evaluated pose individually no appreciable concern to human health. (c) 2009 Elsevier Ltd. All rights reserved.

Historic brownfields and industrial activity in Kingston, Ontario: assessing potential contributions to mercury contamination in sediment of the Cataraqui River.

PubMed

Manion, N C; Campbell, L; Rutter, A

2010-04-01

The waterfront of historic Kingston, Ontario (pop: 113,000) has been used for industrial activities for over a century. More than 40 industries have existed within the inner harbour, and while many of these industries are no longer present, the properties that they operated on remain as potential sources of persistent contamination to the present day, including mercury. To assess the extent and distribution of total mercury (THg) contamination, 21 sediment cores as well as pore water samples were collected within the inner harbour of Kingston. The spatial distribution of THg in the surface sediment is not homogenous; with concentrations in the surface sediment along the southwestern shoreline, adjacent to the former industrial properties, are significantly greater (p<0.01) than the rest of the inner harbour, and were above the Federal severe effect limit (>2000 microg/kg;) guideline for sediment. MeHg was detected in some sediment cores, and was found to have a significant, positive correlation with [THg] in the surface sediment (0-5 cm). THg was not found in storm sewer discharges, but was detected in terrestrial soil near the Kingston Rowing Club at a concentration of more than 4000 microg/kg. Significant [THg] was detected in runoff draining from contaminated shoreline soils, indicating that erosion from terrestrial sources may be an ongoing source of Hg to the sediment. It can be concluded that there is an increased risk over time to surrounding ecosystems where properties with historical contamination are not remediated until they are developed. (c) 2010 Elsevier B.V. All rights reserved.

Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques Using RDX and C-4

NASA Astrophysics Data System (ADS)

Miller, C. J.; Yoder, T. S.

2010-06-01

Explosive trace detection equipment has been deployed to airports for more than a decade. During this time, the need for standardized procedures and calibrated trace amounts for ensuring that the systems are operating properly and detecting the correct explosive has been apparent but a standard representative of a fingerprint has been elusive. Standards are also necessary to evaluate instrumentation in the laboratories during development and prior to deployment to determine sample throughput, probability of detection, false positive/negative rates, ease of use by operator, mechanical and/or software problems that may be encountered, and other pertinent parameters that would result in the equipment being unusable during field operations. Since many laboratories do not have access to nor are allowed to handle explosives, the equipment is tested using techniques aimed at simulating the actual explosives fingerprint. This laboratory study focused on examining the similarities and differences in three different surface contamination techniques that are used to performance test explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples and to offer scenarios where each contamination technique is applicable. The three techniques used were dry transfer deposition of standard solutions using the Transportation Security Laboratory’s (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards onto substrates, and fingerprinting of actual explosives onto substrates. RDX was deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each substrate type using each contamination technique. The substrate types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, and painted metal obtained from a car hood at a junk yard. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal, oil and dirt. The substrates were photographed using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera to determine the difference in the crystalline structure and surface contamination in an attempt to determine differences and similarities associated with current contamination deposition techniques. Some samples were analyzed using scanning electron microscopy (SEM) and some were extracted and analyzed with high performance liquid chromatography (HPLC) or gas chromatography with an electron capture detector (GC-ECD) to quantify the data.

Contamination study

NASA Astrophysics Data System (ADS)

Johnson, R. Barry; Herren, Kenneth A.

1990-09-01

The time dependence of the angular reflectance from molecularly contaminated optical surfaces in the Vacuum Ultraviolet (VUV) is measured. The light scattering measurements are accomplished in situ on optical surfaces in real time during deposition of molecular contaminants. The measurements are taken using non-coherent VUV sources with the predominant wavelengths being the Krypton resonance lines at 1236 and 1600 A. Detection of the scattered light is accomplished using a set of three solar blind VUV photomultipliers. An in-plane VUV BRDF (Bidirectional Reflectance Distribution Functions) experiment is described and details of the ongoing program to characterize optical materials exposed to the space environment is reported.

Method for removal of beryllium contamination from an article

DOEpatents

Simandl, Ronald F.; Hollenbeck, Scott M.

2012-12-25

A method of removal of beryllium contamination from an article is disclosed. The method typically involves dissolving polyisobutylene in a solvent such as hexane to form a tackifier solution, soaking the substrate in the tackifier to produce a preform, and then drying the preform to produce the cleaning medium. The cleaning media are typically used dry, without any liquid cleaning agent to rub the surface of the article and remove the beryllium contamination below a non-detect level. In some embodiments no detectible residue is transferred from the cleaning wipe to the article as a result of the cleaning process.

Survival and detection of rotaviruses on environmental surfaces in day care centers.

PubMed Central

Keswick, B H; Pickering, L K; DuPont, H L; Woodward, W E

1983-01-01

Previously, we demonstrated that children in day care centers commonly experience diarrhea due to rotavirus, giardia, and bacterial pathogens. Multiple agents frequently coexist, and the environment is heavily contaminated with enteric bacteria during outbreaks. A study of environmental surface contamination with rotavirus was performed during three non-outbreak periods. Of 25 samples collected from environmental surfaces and teachers hands at a day care center, 4 (16%) were positive for rotavirus antigen when a fluorescence assay was used. We also examined the survival of two animal viruses, rotavirus SA-11 and poliovirus type 1, and bacteriophage 12 on similar environmental surfaces in a laboratory. Poliovirus type 1 and bacteriophage f2 were more resistant to drying than rotavirus SA-11 and could be recovered after a 90-min exposure on a dry surface. Rotavirus SA-11 could be detected for 30 min. All three viruses survived longer when they were suspended in fecal material than when they were suspended in distilled water. These data suggest that several agents, including rotavirus, can remain viable on contaminated surfaces long enough to be transmitted to susceptible children. This finding helps explain why rotavirus shows a mode of spread like that of parasitic and bacterial agents within day care center settings. PMID:6314896

A flow-cytometry-based method for detecting simultaneously five allergens in a complex food matrix.

PubMed

Otto, Gaetan; Lamote, Amandine; Deckers, Elise; Dumont, Valery; Delahaut, Philippe; Scippo, Marie-Louise; Pleck, Jessica; Hillairet, Caroline; Gillard, Nathalie

2016-12-01

To avoid carry-over contamination with allergens, food manufacturers implement quality control strategies relying primarily on detection of allergenic proteins by ELISA. Although sensitive and specific, this method allowed detection of only one allergen per analysis and effective control policies were thus based on multiplying the number of tests done in order to cover the whole range of allergens. We present in this work an immunoassay for the simultaneous detection of milk, egg, peanut, mustard and crustaceans in cookies samples. The method was based on a combination of flow cytometry with competitive ELISA where microbeads were used as sorbent surface. The test was able to detect the presence of the five allergens with median inhibitory concentrations (IC50) ranging from 2.5 to 15 mg/kg according to the allergen to be detected. The lowest concentrations of contaminants inducing a significant difference of signal between non-contaminated controls and test samples were 2 mg/kg of peanut, 5 mg/kg of crustaceans, 5 mg/kg of milk, 5 mg/kg of mustard and 10 mg/kg of egg. Assay sensitivity was influenced by the concentration of primary antibodies added to the sample extract for the competition and by the concentration of allergenic proteins bound to the surface of the microbeads.

Spatiotemporal Analysis of Microbiological Contamination in New York State Produce Fields following Extensive Flooding from Hurricane Irene, August 2011.

PubMed

Bergholz, Peter W; Strawn, Laura K; Ryan, Gina T; Warchocki, Steven; Wiedmann, Martin

2016-03-01

Although flooding introduces microbiological, chemical, and physical hazards onto croplands, few data are available on the spatial extent, patterns, and development of contamination over time postflooding. To address this paucity of information, we conducted a spatially explicit study of Escherichia coli and Salmonella contamination prevalence and genetic diversity in produce fields after the catastrophic flooding that occurred in New England during 2011. Although no significant differences were detected between the two participating farms, both random forest and logistic regression revealed changes in the spatial pattern of E. coli contamination in drag swab samples over time. Analyses also indicated that E. coli detection was associated with changes in farm management to remediate the land after flooding. In particular, E. coli was widespread in drag swab samples at 21 days postflooding, but the spatial pattern changed by 238 days postflooding such that E. coli was then most prevalent in close proximity to surface water features. The combined results of several population genetics analyses indicated that over time postflooding E. coli populations on the farms (i) changed in composition and (ii) declined overall. Salmonella was primarily detected in surface water features, but some Salmonella strains were isolated from soil and drag swab samples at 21 and 44 days postflooding. Although postflood contamination and land management responses should always be evaluated in the context of each unique farm landscape, our results provide quantitative data on the general patterns of contamination after flooding and support the practice of establishing buffer zones between flood-contaminated cropland and harvestable crops in produce fields.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States

USGS Publications Warehouse

Glassmeyer, Susan T.; Furlong, Edward T.; Kolpin, Dana W.; Batt, Angela L.; Benson, Robert; Boone, J. Scott; Conerly, Octavia D.; Donohue, Maura J.; King, Dawn N.; Kostich, Mitchell S.; Mash, Heath E.; Pfaller, Stacy; Schenck, Kathleen M.; Simmons, Jane Ellen; Varughese, Eunice A.; Vesper, Stephen J.; Villegas, Eric N.; Wilson, Vickie S.

2017-01-01

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To this end, source and treated drinking water samples from 29 drinking water treatment plants (DWTPs) were analyzed as part of a two-phase study to determine whether chemical and microbial constituents, many of which are considered contaminants of emerging concern, were detectable in the waters. Of the 84 chemicals monitored in the 9 Phase I DWTPs, 27 were detected at least once in the source water, and 21 were detected at least once in treated drinking water. In Phase II, which was a broader and more comprehensive assessment, 247 chemical and microbial analytes were measured in 25 DWTPs, with 148 detected at least once in the source water, and 121 detected at least once in the treated drinking water. The frequency of detection was often related to the analyte's contaminant class, as pharmaceuticals and anthropogenic waste indicators tended to be infrequently detected and more easily removed during treatment, while per and polyfluoroalkyl substances and inorganic constituents were both more frequently detected and, overall, more resistant to treatment. The data collected as part of this project will be used to help inform evaluation of unregulated contaminants in surface water, groundwater, and drinking water.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States.

PubMed

Glassmeyer, Susan T; Furlong, Edward T; Kolpin, Dana W; Batt, Angela L; Benson, Robert; Boone, J Scott; Conerly, Octavia; Donohue, Maura J; King, Dawn N; Kostich, Mitchell S; Mash, Heath E; Pfaller, Stacy L; Schenck, Kathleen M; Simmons, Jane Ellen; Varughese, Eunice A; Vesper, Stephen J; Villegas, Eric N; Wilson, Vickie S

2017-03-01

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To this end, source and treated drinking water samples from 29 drinking water treatment plants (DWTPs) were analyzed as part of a two-phase study to determine whether chemical and microbial constituents, many of which are considered contaminants of emerging concern, were detectable in the waters. Of the 84 chemicals monitored in the 9 Phase I DWTPs, 27 were detected at least once in the source water, and 21 were detected at least once in treated drinking water. In Phase II, which was a broader and more comprehensive assessment, 247 chemical and microbial analytes were measured in 25 DWTPs, with 148 detected at least once in the source water, and 121 detected at least once in the treated drinking water. The frequency of detection was often related to the analyte's contaminant class, as pharmaceuticals and anthropogenic waste indicators tended to be infrequently detected and more easily removed during treatment, while per and polyfluoroalkyl substances and inorganic constituents were both more frequently detected and, overall, more resistant to treatment. The data collected as part of this project will be used to help inform evaluation of unregulated contaminants in surface water, groundwater, and drinking water. Published by Elsevier B.V.

Flow cytometric analysis of microbial contamination in food industry technological lines--initial study.

PubMed

Józwa, Wojciech; Czaczyk, Katarzyna

2012-04-02

Flow cytometry constitutes an alternative for traditional methods of microorganisms identification and analysis, including methods requiring cultivation step. It enables the detection of pathogens and other microorganisms contaminants without the need to culture microbial cells meaning that the sample (water, waste or food e.g. milk, wine, beer) may be analysed directly. This leads to a significant reduction of time required for analysis allowing monitoring of production processes and immediate reaction in case of contamination or any disruption occurs. Apart from the analysis of raw materials or products on different stages of manufacturing process, the flow cytometry seems to constitute an ideal tool for the assessment of microbial contamination on the surface of technological lines. In the present work samples comprising smears from 3 different surfaces of technological lines from fruit and vegetable processing company from Greater Poland were analysed directly with flow cytometer. The measured parameters were forward and side scatter of laser light signals allowing the estimation of microbial cell contents in each sample. Flow cytometric analysis of the surface of food industry production lines enable the preliminary evaluation of microbial contamination within few minutes from the moment of sample arrival without the need of sample pretreatment. The presented method of fl ow cytometric initial evaluation of microbial state of food industry technological lines demonstrated its potential for developing a robust, routine method for the rapid and labor-saving detection of microbial contamination in food industry.

Nano-TiO2-based photocatalytic disinfection of environmental surfaces contaminated by meticillin-resistant Staphylococcus aureus.

PubMed

Petti, S; Messano, G A

2016-05-01

Traditional cleaning and disinfection methods are inefficient for complete decontamination of hospital surfaces from meticillin-resistant Staphylococcus aureus (MRSA). Additional methods, such as nano-TiO2-based photocatalytic disinfection (PCD), could be helpful. To evaluate anti-MRSA activity of PCD on polyvinyl chloride (PVC) surfaces in natural-like conditions. Two identical PVC surfaces were used, and nano-TiO2 was incorporated into one of them. The surfaces were contaminated with MRSA isolated from hospitalized patients using a mist sprayer to simulate the mode of environmental contamination caused by a carrier. MRSA cell density was assessed before contamination until 180min after contamination using Rodac plates. The differences between test and control surfaces in terms of MRSA density and log MRSA density reduction were assessed using parametric and non-parametric statistical tests. Five strains were tested, and each strain was tested five times. The highest median MRSA densities [46.3 and 43.1 colony-forming units (cfu)/cm(2) for control and test surfaces, respectively] were detected 45min after contamination. Median MRSA densities 180min after contamination were 10.1 and 0.7cfu/cm(2) for control and test surfaces, respectively (P<0.01). Log MRSA density reduction attributable to PCD was 1.16logcfu/cm(2), corresponding to 93% reduction of the baseline MRSA contamination. The disinfectant activity remained stable throughout the 25 testing occasions, despite between-test cleaning and disinfection. The anti-MRSA activity of PCD was compatible with the benchmark for surface hygiene in hospitals (<1cfu/cm(2)), but required 3h of exposure to photocatalysis. Thus, PCD could be considered for non-clinical surfaces. However, for clinical surfaces, PCD should be regarded as supplemental to conventional decontamination procedures, rather than an alternative. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Suitability of artificial sweeteners as indicators of raw wastewater contamination in surface water and groundwater.

PubMed

Tran, Ngoc Han; Hu, Jiangyong; Li, Jinhua; Ong, Say Leong

2014-01-01

There is no quantitative data on the occurrence of artificial sweeteners in the aquatic environment in Southeast Asian countries, particularly no information on their suitability as indicators of raw wastewater contamination on surface water and groundwater. This study provided the first quantitative information on the occurrence of artificial sweeteners in raw wastewater, surface water and groundwater in the urban catchment area in Singapore. Acesulfame, cyclamate, saccharin, and sucralose were ubiquitous in raw wastewater samples at concentrations in the range of ng/L-μg/L, while other sweeteners were not found or found only in a few of the raw wastewater samples. Residential and commercial effluents were demonstrated to be the two main sources of artificial sweeteners entering the municipal sewer systems. Relatively higher concentrations of the detected sweeteners were frequently found in surface waters at the sampling sites located in the residential/commercial areas. No significant difference in the concentrations of the detected sweeteners in surface water or groundwater was noted between wet and dry weather conditions (unpaired T-test, p> 0.05). Relatively higher concentrations and detection frequencies of acesulfame, cyclamate and saccharin in surface water samples were observed at the potentially impacted sampling sites, while these sweeteners were absent in most of the background surface water samples. Similarly, acesulfame, cyclamate, and saccharin were found in most groundwater samples at the monitoring well (GW6), which is located close to known leaking sewer segment; whereas these were absent in the background monitoring well, which is located in the catchment with no known wastewater sources. Taken together, the results suggest that acesulfame, cyclamate, and saccharin can be used as potential indicators of raw wastewater contamination in surface water and groundwater. Copyright © 2013 Elsevier Ltd. All rights reserved.

Teschoviruses as Indicators of Porcine Fecal Contamination of Surface Water

PubMed Central

Jiménez-Clavero, Miguel Angel; Fernández, Carlos; Ortiz, José Antonio; Pro, Javier; Carbonell, Gregoria; Tarazona, José Vicente; Roblas, Neftalí; Ley, Victoria

2003-01-01

Teschoviruses specifically infect pigs and are shed in pig feces. Hence, their presence in water should indicate contamination with pig fecal residues. To assess this hypothesis, we have developed a real-time reverse transcriptase PCR (RT-PCR) method that allows the quantitative detection of pig teschovirus (PTV) RNA. The method is able to detect 92 fg of PTV RNA per ml of sample. Using this method, we have detected the presence of PTV RNA in water and fecal samples from all pig farms examined (n = 5). Feces from other animal species (cattle, sheep, and goats) were negative in this test. To compare the PTV RNA detection method with conventional chemical determinations currently in use for evaluation of water contamination, we analyzed water samples collected downstream from a pig slurry spillage site. We have found a positive correlation within both types of determinations. The sensitivity of the PTV detection assay was similar to that achieved by unspecific organic matter determination and superior to all other conventional chemical analyses performed. Furthermore, the new method is highly specific, revealing the porcine origin of the contamination, a feature that is lacking in currently available methods for the assessment of water contamination. PMID:14532098

Integrating multiple lines of evidence to assess biological hazards of complex mixtures: A case study in the Maumee River

EPA Science Inventory

Product Description:Due to technological improvements, increasing numbers of chemical contaminants are being detected in surface waters nation-wide, including the Great Lakes. Methods are needed to understand what impact these complex mixtures of contaminants can have on aquatic ...

Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

USDA-ARS?s Scientific Manuscript database

Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by ...

Imaging surface plasmon resonance detection for T-2 toxin in wheat

USDA-ARS?s Scientific Manuscript database

T-2 toxin is a trichothecene (Type A) mycotoxin harmful to humans and animals. It is produced by mainly Fusarium species, particularly F. sporotrichoides. Fusarium species often contaminate grains such as corn, wheat, barley, oats, rice and rye. T-2 toxin contamination in grains has been observed mo...

Occurrence of organic wastewater and other contaminants in cave streams in northeastern Oklahoma and northwestern Arkansas

USGS Publications Warehouse

Bidwell, Joseph R.; Becker, C.; Hensley, S.; Stark, R.; Meyer, M.T.

2010-01-01

The prevalence of organic wastewater compounds in surface waters of the United States has been reported in a number of recent studies. In karstic areas, surface contaminants might be transported to groundwater and, ultimately, cave ecosystems, where they might impact resident biota. In this study, polar organic chemical integrative samplers (POCISs) and semipermeable membrane devices (SPMDs) were deployed in six caves and two surface-water sites located within the Ozark Plateau of northeastern Oklahoma and northwestern Arkansas in order to detect potential chemical contaminants in these systems. All caves sampled were known to contain populations of the threatened Ozark cavefish (Amblyopsis rosae). The surface-water site in Oklahoma was downstream from the outfall of a municipal wastewater treatment plant and a previous study indicated a hydrologic link between this stream and one of the caves. A total of 83 chemicals were detected in the POCIS and SPMD extracts from the surface-water and cave sites. Of these, 55 chemicals were detected in the caves. Regardless of the sampler used, more compounds were detected in the Oklahoma surface-water site than in the Arkansas site or the caves. The organic wastewater chemicals with the greatest mass measured in the sampler extracts included sterols (cholesterol and ??-sitosterol), plasticizers [diethylhexylphthalate and tris (2-butoxyethyl) phosphate], the herbicide bromacil, and the fragrance indole. Sampler extracts from most of the cave sites did not contain many wastewater contaminants, although extracts from samplers in the Oklahoma surfacewater site and the cave hydrologically linked to it had similar levels of diethylhexyphthalate and common detections of carbamazapine, sulfamethoxazole, benzophenone, N-diethyl-3-methylbenzamide (DEET), and octophenol monoethoxylate. Further evaluation of this system is warranted due to potential ongoing transport of wastewaterassociated chemicals into the cave. Halogenated organics found in caves and surface-water sites included brominated flame retardants, organochlorine pesticides (chlordane and nonachlor), and polychlorinated biphenyls. The placement of samplers in the caves (near the cave mouth compared to farther in the system) might have influenced the number of halogenated organics detected due to possible aerial transport of residues. Guano from cave-dwelling bats also might have been a source of some of these chlorinated organics. Seven-day survival and growth bioassays with fathead minnows (Pimephales promelas) exposed to samples of cave water indicated initial toxicity in water from two of the caves, but these effects were transient, with no toxicity observed in follow-up tests. ??Springer Science+Business Media, LLC 2009.

Comparison of two filtration-elution procedures to improve the standard methods ISO 10705-1 & 2 for bacteriophage detection in groundwater, surface water and finished water samples.

PubMed

Helmi, K; Jacob, P; Charni-Ben-Tabassi, N; Delabre, K; Arnal, C

2011-09-01

To select a reliable method for bacteriophage concentration prior detection by culture from surface water, groundwater and drinking water to enhance the sensitivity of the standard methods ISO 10705-1 & 2. Artificially contaminated (groundwater and drinking water) and naturally contaminated (surface water) 1-litre samples were processed for bacteriophages detection. The spiked samples were inoculated with about 150 PFU of F-specific RNA bacteriophages and somatic coliphages using wastewater. Bacteriophage detection in the water samples was achieved using the standard method without and with a concentration step (electropositive Anodisc membrane or a pretreated electronegative Micro Filtration membrane, MF). For artificially contaminated matrices (drinking and ground waters), recovery rates using the concentration step were superior to 70% whilst analyses without concentration step mainly led to false negative results. Besides, the MF membrane presented higher performances compared with the Anodisc membrane. The concentration of a large volume of water (up to one litre) on a filter membrane avoids false negative results obtained by direct analysis as it allows detecting low number of bacteriophages in water samples. The addition of concentration step before applying the standard method could be useful to enhance the reliability of bacteriophages monitoring in water samples as bio-indicators to highlight faecal pollution. © No claim to French Government works. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

Contamination detection NDE for cleaning process inspection

NASA Technical Reports Server (NTRS)

Marinelli, W. J.; Dicristina, V.; Sonnenfroh, D.; Blair, D.

1995-01-01

In the joining of multilayer materials, and in welding, the cleanliness of the joining surface may play a large role in the quality of the resulting bond. No non-intrusive techniques are currently available for the rapid measurement of contamination on large or irregularly shaped structures prior to the joining process. An innovative technique for the measurement of contaminant levels in these structures using laser based imaging is presented. The approach uses an ultraviolet excimer laser to illuminate large and/or irregular surface areas. The UV light induces fluorescence and is scattered from the contaminants. The illuminated area is viewed by an image-intensified CCD (charge coupled device) camera interfaced to a PC-based computer. The camera measures the fluorescence and/or scattering from the contaminants for comparison with established standards. Single shot measurements of contamination levels are possible. Hence, the technique may be used for on-line NDE testing during manufacturing processes.

Prevalence and characteristics of ESBL-producing E. coli in Dutch recreational waters influenced by wastewater treatment plants.

PubMed

Blaak, Hetty; de Kruijf, Patrick; Hamidjaja, Raditijo A; van Hoek, Angela H A M; de Roda Husman, Ana Maria; Schets, Franciska M

2014-07-16

Outside health care settings, people may acquire ESBL-producing bacteria through different exposure routes, including contact with human or animal carriers or consumption of contaminated food. However, contact with faecally contaminated surface water may also represent a possible exposure route. The current study investigated the prevalence and characteristics of ESBL-producing Escherichia coli in four Dutch recreational waters and the possible role of nearby waste water treatment plants (WWTP) as contamination source. Isolates from recreational waters were compared with isolates from WWTP effluents, from surface water upstream of the WWTPs, at WWTP discharge points, and in connecting water bodies not influenced by the studied WWTPs. ESBL-producing E. coli were detected in all four recreational waters, with an average concentration of 1.3 colony forming units/100ml, and in 62% of all samples. In surface waters not influenced by the studied WWTPs, ESBL-producing E. coli were detected in similar concentrations, indicating the existence of additional ESBL-E. coli contamination sources. Isolates with identical ESBL-genes, phylogenetic background, antibiotic resistance profiles, and sequence type, were obtained from effluent and different surface water sites in the same watershed, on the same day; occasionally this included isolates from recreational waters. Recreational waters were identified as a potential exposure source of ESBL-producing E. coli. WWTPs were shown to contribute to the presence of these bacteria in surface waters, but other (yet unidentified) sources likely co-contribute. Copyright © 2014 Elsevier B.V. All rights reserved.

Field Analysis of Microbial Contamination Using Three Molecular Methods in Parallel

NASA Technical Reports Server (NTRS)

Morris, H.; Stimpson, E.; Schenk, A.; Kish, A.; Damon, M.; Monaco, L.; Wainwright, N.; Steele, A.

2010-01-01

Advanced technologies with the capability of detecting microbial contamination remain an integral tool for the next stage of space agency proposed exploration missions. To maintain a clean, operational spacecraft environment with minimal potential for forward contamination, such technology is a necessity, particularly, the ability to analyze samples near the point of collection and in real-time both for conducting biological scientific experiments and for performing routine monitoring operations. Multiple molecular methods for detecting microbial contamination are available, but many are either too large or not validated for use on spacecraft. Two methods, the adenosine- triphosphate (ATP) and Limulus Amebocyte Lysate (LAL) assays have been approved by the NASA Planetary Protection Office for the assessment of microbial contamination on spacecraft surfaces. We present the first parallel field analysis of microbial contamination pre- and post-cleaning using these two methods as well as universal primer-based polymerase chain reaction (PCR).

Optimization of a chemical identification algorithm

NASA Astrophysics Data System (ADS)

Chyba, Thomas H.; Fisk, Brian; Gunning, Christin; Farley, Kevin; Polizzi, Amber; Baughman, David; Simpson, Steven; Slamani, Mohamed-Adel; Almassy, Robert; Da Re, Ryan; Li, Eunice; MacDonald, Steve; Slamani, Ahmed; Mitchell, Scott A.; Pendell-Jones, Jay; Reed, Timothy L.; Emge, Darren

2010-04-01

A procedure to evaluate and optimize the performance of a chemical identification algorithm is presented. The Joint Contaminated Surface Detector (JCSD) employs Raman spectroscopy to detect and identify surface chemical contamination. JCSD measurements of chemical warfare agents, simulants, toxic industrial chemicals, interferents and bare surface backgrounds were made in the laboratory and under realistic field conditions. A test data suite, developed from these measurements, is used to benchmark algorithm performance throughout the improvement process. In any one measurement, one of many possible targets can be present along with interferents and surfaces. The detection results are expressed as a 2-category classification problem so that Receiver Operating Characteristic (ROC) techniques can be applied. The limitations of applying this framework to chemical detection problems are discussed along with means to mitigate them. Algorithmic performance is optimized globally using robust Design of Experiments and Taguchi techniques. These methods require figures of merit to trade off between false alarms and detection probability. Several figures of merit, including the Matthews Correlation Coefficient and the Taguchi Signal-to-Noise Ratio are compared. Following the optimization of global parameters which govern the algorithm behavior across all target chemicals, ROC techniques are employed to optimize chemical-specific parameters to further improve performance.

Determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry.

PubMed

Janssens, T; Brouwers, E E M; de Vos, J P; de Vries, N; Schellens, J H M; Beijnen, J H

2015-09-01

The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology centres, 46.3 and 68.9% of the sampled surfaces demonstrated platinum contamination, respectively. Highest platinum levels were found in the preparation rooms (44.6 pg cm(-2)) in veterinary centres, while maximal levels in human centres were found in oncology patient-only toilets (725 pg cm(-2)). Transference of platinum by workers outside areas where antineoplastic drugs were handled was observed in veterinary and human oncology centres. In conclusion, only low levels of platinum contamination attributable to carboplatin were found in the sampled veterinary oncology centres. However, dispersion of platinum outside areas where antineoplastic drugs were handled was detected in veterinary and human oncology centres. Consequently, not only personnel, but also others may be exposed to platinum. © 2013 Blackwell Publishing Ltd.

Nipah Virus Contamination of Hospital Surfaces during Outbreaks, Bangladesh, 2013–2014

PubMed Central

Sazzad, Hossain M.S.; Luby, Stephen P.; Sturm-Ramirez, Katharine; Bhuiyan, Mejbah Uddin; Rahman, Mohammed Ziaur; Islam, Md Muzahidul; Ströher, Ute; Sultana, Sharmin; Kafi, Mohammad Abdullah Heel; Daszak, Peter; Rahman, Mahmudur; Gurley, Emily S.

2018-01-01

Nipah virus (NiV) has been transmitted from patient to caregivers in Bangladesh presumably through oral secretions. We aimed to detect whether NiV-infected patients contaminate hospital surfaces with the virus. During December 2013–April 2014, we collected 1 swab sample from 5 surfaces near NiV-infected patients and tested surface and oral swab samples by real-time reverse transcription PCR for NiV RNA. We identified 16 Nipah patients; 12 cases were laboratory-confirmed and 4 probable. Of the 12 laboratory-confirmed cases, 10 showed NiV RNA in oral swab specimens. We obtained surface swab samples for 6 Nipah patients; 5 had evidence of NiV RNA on >1 surface: 4 patients contaminated towels, 3 bed sheets, and 1 the bed rail. Patients with NiV RNA in oral swab samples were significantly more likely than other Nipah patients to die. To reduce the risk for fomite transmission of NiV, infection control should target hospital surfaces. PMID:29260663

Nipah Virus Contamination of Hospital Surfaces during Outbreaks, Bangladesh, 2013-2014.

PubMed

Hassan, Md Zakiul; Sazzad, Hossain M S; Luby, Stephen P; Sturm-Ramirez, Katharine; Bhuiyan, Mejbah Uddin; Rahman, Mohammed Ziaur; Islam, Md Muzahidul; Ströher, Ute; Sultana, Sharmin; Kafi, Mohammad Abdullah Heel; Daszak, Peter; Rahman, Mahmudur; Gurley, Emily S

2018-01-01

Nipah virus (NiV) has been transmitted from patient to caregivers in Bangladesh presumably through oral secretions. We aimed to detect whether NiV-infected patients contaminate hospital surfaces with the virus. During December 2013-April 2014, we collected 1 swab sample from 5 surfaces near NiV-infected patients and tested surface and oral swab samples by real-time reverse transcription PCR for NiV RNA. We identified 16 Nipah patients; 12 cases were laboratory-confirmed and 4 probable. Of the 12 laboratory-confirmed cases, 10 showed NiV RNA in oral swab specimens. We obtained surface swab samples for 6 Nipah patients; 5 had evidence of NiV RNA on >1 surface: 4 patients contaminated towels, 3 bed sheets, and 1 the bed rail. Patients with NiV RNA in oral swab samples were significantly more likely than other Nipah patients to die. To reduce the risk for fomite transmission of NiV, infection control should target hospital surfaces.

Plasma cleaning of nanoparticles from EUV mask materials by electrostatics

NASA Astrophysics Data System (ADS)

Lytle, W. M.; Raju, R.; Shin, H.; Das, C.; Neumann, M. J.; Ruzic, D. N.

2008-03-01

Particle contamination on surfaces used in extreme ultraviolet (EUV) mask blank deposition, mask fabrication, and patterned mask handling must be avoided since the contamination can create significant distortions and loss of reflectivity. Particles on the order of 10nm are problematic during MLM mirror fabrication, since the introduced defects disrupt the local Bragg planes. The most serious problem is the accumulation of particles on surfaces of patterned blanks during EUV light exposure, since > 25nm particles will be printed without an out-of-focus pellicle. Particle contaminants are also a problem with direct imprint processes since defects are printed every time. Plasma Assisted Cleaning by Electrostatics (PACE) works by utilizing a helicon plasma as well as a pulsed DC substrate bias to charge particle and repel them electrostatically from the surface. Removal of this nature is a dry cleaning method and removes contamination perpendicular from the surface instead of rolling or sweeping the particles off the surface, a benefit when cleaning patterned surfaces where contamination can be rolled or trapped between features. Also, an entire mask can be cleaned at once since the plasma can cover the entire surface, thus there is no need to focus in on an area to clean. Sophisticated particle contamination detection system utilizing high power laser called DEFCON is developed to analyze the particle removal after PACE cleaning process. PACE has shown greater than 90 % particle removal efficiencies for 30 to 220 nm PSL particles on ruthenium capped quartz. Removal results for silicon surfaces and quartz surfaces show similar removal efficiencies. Results of cleaning 80 nm PSL spheres from silicon substrates will be shown.

Advanced capabilities and applications of a sputter-RBS system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brijs, B.; Deleu, J.; Beyer, G.

1999-06-10

In previous experiments, sputter-RBS{sup 1} has proven to be an ideal tool to study the interaction of low energy ions. This contribution employs the same methodology to identify surface contamination induced during sputtering and to the determine absolute sputter yields. In the first experiment ERDA analysis was used to study the evolution of Hydrogen contamination during sputter-RBS experiments. Since the determination of Hydrogen concentration in very thin near surface layers is frequently limited by the presence of a strong surface peak of Hydrogen originating from adsorbed contamination of the residual vacuum, removal of this contamination would increase the sensitivity formore » Hydrogen detection in the near sub surface drastically. Therefore low energy (12 keV) Argon sputtering was used to remove the Hydrogen surface peak. However enhanced Hydrogen adsorption was observed related to the Ar dose. This experiment shows that severe vacuum conditions and the use of high current densities/sputter yields are a prerequisite for an efficient detection of Hydrogen in the near surface layers. In the second experiment, an attempt was made to determine the sputter yield of Cu during low energy (12 keV) Oxygen bombardment. In order to determine the accumulated dose of the low energy ion beam, a separate Faraday cup in combination with a remote controlled current have been added to the existing sputter-RBS set-up. Alternating sputtering and RBS analysis seem to be an adequate tool for the determination of the absolute sputter yield of Cu and this as well in the as under steady state conditions.« less

Continuous low-level aquatic monitoring (CLAM) samplers for pesticide contaminant screening in urban runoff: Analytical approach and a field test case.

PubMed

Ensminger, Michael P; Vasquez, Martice; Tsai, Hsing-Ju; Mohammed, Sarah; Van Scoy, A; Goodell, Korena; Cho, Gail; Goh, Kean S

2017-10-01

Monitoring of surface waters for organic contaminants is costly. Grab water sampling often results in non-detects for organic contaminants due to missing a pulse event or analytical instrumentation limitations with a small sample size. Continuous Low-Level Aquatic Monitoring (CLAM) samplers (C.I.Agent ® Solutions) continually extract and concentrate organic contaminants in surface water onto a solid phase extraction disk. Utilizing CLAM samplers, we developed a broad spectrum analytical screen for monitoring organic contaminants in urban runoff. An intermediate polarity solid phase, hydrophobic/lipophilic balance (HLB), was chosen as the sorbent for the CLAM to target a broad range of compounds. Eighteen urban-use pesticides and pesticide degradates were targeted for analysis by LC/MS/MS, with recoveries between 59 and 135% in laboratory studies. In field studies, CLAM samplers were deployed at discrete time points from February 2015 to March 2016. Half of the targeted chemicals were detected with reporting limits up to 90 times lower than routine 1-L grab samples with good precision between field replicates. In a final deployment, CLAM samplers were compared to 1-L water samples. In this side-by-side comparison, imidacloprid, fipronil, and three fipronil degradates were detected by the CLAM sampler but only imidacloprid and fipronil sulfone were detected in the water samples. However, concentrations of fipronil sulfone and imidacloprid were significantly lower with the CLAM and a transient spike of diuron was not detected. Although the CLAM sampler has limitations, it can be a powerful tool for development of more focused and informed monitoring efforts based on pre-identified targets in the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quality of water and chemistry of bottom sediment in the Rillito Creek basin, Tucson, Arizona, 1986-92

USGS Publications Warehouse

Tadayon, Saeid; Smith, C.F.

1994-01-01

Data were collected on physical properties and chemistry of 4 surface water, l4 ground water, and 4 bottom sediment sites in the Rillito Creek basin where artificial recharge of surface runoff is being considered. Concentrations of suspended sediment in streams generally increased with increases in streamflow and were higher during the summer. The surface water is a calcium and bicarbonate type, and the ground water is calcium sodium and bicarbonate type. Total trace ek=nents in surface water that exceeded the U.S. Environmental Protection Agency primary maximum contaminant levels for drinking-water standards were barium, beryllium, cadmium, chromium, lead, mercury and nickel. Most unfiltered samples for suspended gross alpha as uranium, and unadjusted gross alpha plus gross beta in surface water exceeded the U.S. Environmental Protection Agency and the State of Arizona drinking-water standards. Comparisons of trace- element concentrations in bottom sediment with those in soils of the western conterminous United States generally indicate similar concentrations for most of the trace elements, with the exceptions of scandium and tin. The maximum concentration of total nitrite plus nitrate as nitrogen in three ground- samples and total lead in one ground-water sample exceeded U.S. Environmental Protection Agency primary maximum contaminant levels for drinking- water standards, respectively. Seven organochlorine pesticides were detected in surface-water samples and nine in bottom-sediment samples. Three priority pollutants were detected in surface water, two were detected in ground water, and eleven were detected in bottom sediment. Low concentrations of oil and grease were detected in surface-water and bottom- sediment samples.

Mapping of explosive contamination using GC/chemiluminescence and ion mobility spectrometry techniques

NASA Astrophysics Data System (ADS)

Miller, Carla J.; Glenn, D. F.; Hartenstein, Steven D.; Hallowell, Susan F.

1998-12-01

Recent efforts at the Idaho National Engineering and Environmental Laboratory (INEEL) have included mapping explosive contamination resulting from manufacturing and carrying improvised explosive devices (IEDs). Two types of trace detection equipment were used to determine levels of contamination from designated sampling areas. A total of twenty IEDs were constructed: ten using TNT and ten using C-4. Two test scenarios were used. The first scenario tracked the activities of a manufacturer who straps the device onto an independent courier. The courier then performed a series of activities to simulate waiting in an airport. The second scenario tracked the activities of a manufacturer who also served as the courier. A sample set for each test consisted of thirty samples from various locations on each IED manufacturer, thirty from each IED courier, twenty-five from the manufacturing area, and twenty-five from the courier area. Pre-samples and post-samples were collected for analysis with each detection technique. Samples analyzed by gc/chemiluminescence were taken by swiping a teflon- coated sampling swipe across the surface of the sampling area to pick up any explosive particles. Samples analyzed by ion mobility spectrometry (IMS) were taken from the clothing of the manufacturer and courier by vacuuming the surface and collecting particulates on a fiberglass filter. Samples for IMS analysis from the manufacturing and courier rooms were taken by wiping a cotton sampling swipe across the surface area. Currently, building IEDs and monitoring the explosive contamination is being directed toward detection with portal monitors.

Dissolved organic matter fluorescence at wavelength 275/342 nm as a key indicator for detection of point-source contamination in a large Chinese drinking water lake.

PubMed

Zhou, Yongqiang; Jeppesen, Erik; Zhang, Yunlin; Shi, Kun; Liu, Xiaohan; Zhu, Guangwei

2016-02-01

Surface drinking water sources have been threatened globally and there have been few attempts to detect point-source contamination in these waters using chromophoric dissolved organic matter (CDOM) fluorescence. To determine the optimal wavelength derived from CDOM fluorescence as an indicator of point-source contamination in drinking waters, a combination of field campaigns in Lake Qiandao and a laboratory wastewater addition experiment was used. Parallel factor (PARAFAC) analysis identified six components, including three humic-like, two tryptophan-like, and one tyrosine-like component. All metrics showed strong correlation with wastewater addition (r(2) > 0.90, p < 0.0001). Both the field campaigns and the laboratory contamination experiment revealed that CDOM fluorescence at 275/342 nm was the most responsive wavelength to the point-source contamination in the lake. Our results suggest that pollutants in Lake Qiandao had the highest concentrations in the river mouths of upstream inflow tributaries and the single wavelength at 275/342 nm may be adapted for online or in situ fluorescence measurements as an early warning of contamination events. This study demonstrates the potential utility of CDOM fluorescence to monitor water quality in surface drinking water sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

A microscopy approach for in situ inspection of micro-coordinate measurement machine styli for contamination

NASA Astrophysics Data System (ADS)

Feng, Xiaobing; Pascal, Jonathan; Lawes, Simon

2017-09-01

During the process of measurement using a micro-coordinate measurement machine (µCMM) contamination gradually builds up on the surface of the stylus tip and affects the dimensional accuracy of the measurement. Regular inspection of the stylus for contamination is essential to determine the appropriate cleaning interval and prevent the dimensional error from becoming significant. However, in situ inspection of a µCMM stylus is challenging due to the size, spherical shape, material and surface properties of a typical stylus. To address this challenge, this study evaluates several non-contact measurement technologies for in situ stylus inspection and, based on those findings, proposes a cost-effective microscopy approach. The operational principle is then demonstrated by an automated prototype, coordinated directly by the CMM software MCOSMOS, with an effective threshold of detection as low as 400 nm and a large field of view and depth of field. The level of contamination on the stylus has been found to increase steadily with the number of measurement contacts made. Once excessive contamination is detected on the stylus, measurement should be stopped and a stylus cleaning procedure should be performed to avoid affecting measurement accuracy.

Seasonality of Cryptosporidium oocyst detection in surface waters of Meru, Kenya as determined by two isolation methods followed by PCR

PubMed Central

Muchiri, John M.; Ascolillo, Luke; Mugambi, Mutuma; Mutwiri, Titus; Ward, Honorine D.; Naumova, Elena N.; Egorov, Andrey I.; Cohen, Seth; Else, James G.; Griffiths, Jeffrey K.

2009-01-01

Meru, Kenya has watersheds which are shared by wildlife, humans and domesticated animals. These surface waters can be contaminated by the waterborne pathogen Cryptosporidium. To quantify the seasonality and prevalence of Cryptosporidium in Meru regional surface waters, we used a calcium carbonate flocculation (CCF) and sucrose floatation method, and a filtration and immunomagnetic bead separation method, each of which used PCR for Cryptosporidium detection and genotyping. Monthly water samples were collected from January through June in 2003 and 2004, bracketing two April-May rainy seasons. We detected significant seasonality with 8 of 9 positive samples from May and June (p < 0.0014), which followed peak rainy season precipitation and includes some of the subsequent dry season. Six of 9 positive samples revealed C. parvum, and 3 contained C. andersoni. None contained C. hominis. Our results indicate that Meru surface waters are Cryptosporidium-contaminated at the end of rainy seasons, consistent with the timing of human infections reported by others from East Africa and contrasting with the onset of rainy season peak incidence reported from West Africa. PMID:18957776

Hyperspectral imaging technique for detection of poultry fecal residues on food processing equipments

NASA Astrophysics Data System (ADS)

Cho, Byoung-Kwan; Kim, Moon S.; Chen, Yud-Ren

2005-11-01

Emerging concerns about safety and security in current mass production of food products necessitate rapid and reliable inspection for contaminant-free products. Diluted fecal residues on poultry processing plant equipment surface, not easily discernable from water by human eye, are contamination sources for poultry carcasses. Development of sensitive detection methods for fecal residues is essential to ensure safe production of poultry carcasses. Hyperspectral imaging techniques have shown good potential for detecting of the presence of fecal and other biological substances on food and processing equipment surfaces. In this study, use of high spatial resolution hyperspectral reflectance and fluorescence imaging (with UV-A excitation) is presented as a tool for selecting a few multispectral bands to detect diluted fecal and ingesta residues on materials used for manufacturing processing equipment. Reflectance and fluorescence imaging methods were compared for potential detection of a range of diluted fecal residues on the surfaces of processing plant equipment. Results showed that low concentrations of poultry feces and ingesta, diluted up to 1:100 by weight with double distilled water, could be detected using hyperspectral fluorescence images with an accuracy of 97.2%. Spectral bands determined in this study could be used for developing a real-time multispectral inspection device for detection of harmful organic residues on processing plant equipment.

Quality of water and chemistry of bottom sediment in the Rillito Creek basin, Tucson, Arizona, 1992-93

USGS Publications Warehouse

Tadayon, Saeid

1995-01-01

Physical and chemical data were collected from four surface-water sites, six ground-water sites, and two bottom-sediment sites during 1992-93. Specific conductance, hardness, alkalinity, and dissolved- solids concentrations generally were higher in ground water than in surface water. The median concentrations of dissolved major ions, with the exception of potassium, were higher in ground water than in surface water. In surface water and ground water, calcium was the dominant cation, and bicarbonate was the dominant anion. Concentrations of dissolved nitrite and nitrite plus nitrate in surface water and ground water did not exceed the U.S. Environmental Protection Agency maximum contaminant levels of 1 and 10 milligrams per liter for drinking water, respectively. Ammonium plus organic nitrogen in bottom sediment was detected at the highest concentration of any nitrogen species. Median values for most of the dissolved trace elements in surface water and ground water were below the detection levels. Dissolved trace elements in surface water and ground water did not exceed the U.S. Environmental Protection Agency maximum contaminant levels for drinking water. Trace-element concentrations in bottom sediment were similar to trace-element concentrations reported for soils of the western conterminous United States. Several organochlorine pesticides and priority pollutants were detected in surface-water and bottom-sediment samples; however, they did not exceed water-quality standards. Pesticides or priority pollutants were not detected in ground-water samples.

A monitoring of chemical contaminants in waters used for field irrigation and livestock watering in the Veneto region (Italy), using bioassays as a screening tool.

PubMed

De Liguoro, Marco; Bona, Mirco Dalla; Gallina, Guglielmo; Capolongo, Francesca; Gallocchio, Federica; Binato, Giovanni; Di Leva, Vincenzo

2014-03-01

In this study, 50 livestock watering sources (ground water) and 50 field irrigation sources (surface water) from various industrialised areas of the Veneto region were monitored for chemical contaminants. From each site, four water samples (one in each season) were collected during the period from summer 2009 through to spring 2010. Surface water samples and ground water samples were first screened for toxicity using the growth inhibition test on Pseudokirchneriella subcapitata and the immobilisation test on Daphnia magna, respectively. Then, based on the results of these toxicity tests, 28 ground water samples and 26 surface water samples were submitted to chemical analysis for various contaminants (insecticides/acaricides, fungicides, herbicides, metals and anions) by means of UPLC-MS(n) HPLC-MS(n), AAS and IEC. With the exception of one surface water sample where the total pesticides concentration was greater than 4 μg L(-1), positive samples (51.9 %) showed only traces (nanograms per liter) of pesticides. Metals were generally under the detection limit. High concentrations of chlorines (up to 692 mg L(-1)) were found in some ground water samples while some surface water samples showed an excess of nitrites (up to 336 mg L(-1)). Detected levels of contamination were generally too low to justify the toxicity recorded in bioassays, especially in the case of surface water samples, and analytical results painted quite a reassuring picture, while tests on P. subcapitata showed a strong growth inhibition activity. It was concluded that, from an ecotoxicological point of view, surface waters used for field irrigation in the Veneto region cannot be considered safe.

Evaluation of test equipment for the detection of contamination on electronic circuits

NASA Astrophysics Data System (ADS)

Bergendahl, C. G.; Dunn, B. D.

1984-08-01

The reproducibility, sensitivity and ease of operation of test equipment for the detection of ionizable contaminants on the surface of printed circuit assemblies were assessed. The characteristics of the test equipment are described. Soldering fluxes were chosen as contaminants and were applied in controlled amounts to printed-circuit board assemblies possessing two different component populations. Results show that the relationship between equipment readings varies with flux type. Each kind of test equipment gives a good measure of board cleanliness, although reservations exist concerning the interpretation of such results. A test method for the analysis of total (organic and inorganic) halides in solder fluxes is presented.

Surface-enhanced Raman for monitoring toxins in water

NASA Astrophysics Data System (ADS)

Spencer, Kevin M.; Sylvia, James M.; Clauson, Susan L.; Bertone, Jane F.; Christesen, Steven D.

2004-02-01

Protection of the drinking water supply from a terrorist attack is of critical importance. Since the water supply is vast, contamination prevention is difficult. Therefore, rapid detection of contaminants, whether a military chemical/biological threat, a hazardous chemical spill, naturally occurring toxins, or bacterial build-up is a priority. The development of rapid environmentally portable and stable monitors that allow continuous monitoring of the water supply is ideal. EIC Laboratories has been developing Surface-Enhanced Raman Spectroscopy (SERS) to detect chemical agents, toxic industrial chemicals (TICs), viruses, cyanotoxins and bacterial agents. SERS is an ideal technique for the Joint Service Agent Water Monitor (JSAWM). SERS uses the enhanced Raman signals observed when an analyte adsorbs to a roughened metal substrate to enable trace detection. Proper development of the metal substrate will optimize the sensitivity and selectivity towards the analytes of interest.

Impact of closed-system drug transfer device on exposure of environment and healthcare provider to cyclophosphamide in Japanese hospital.

PubMed

Miyake, Tomohiro; Iwamoto, Takuya; Tanimura, Manabu; Okuda, Masahiro

2013-12-01

In spite of current recommended safe handling procedures, the potential for the exposure of healthcare providers to hazardous drugs exists in the workplace. A reliance on biological safety cabinets to provide total protection against the exposure to hazardous drugs is insufficient. Preventing workplace contamination is the best strategy to minimize cytotoxic drug exposure in healthcare providers. This study was conducted to compare surface contamination and personnel exposure to cyclophosphamide before and after the implementation of a closed-system drug transfer device, PhaSeal, under the influence of cleaning according to the Japanese guidelines. Personnel exposure was evaluated by collecting 24 h urine samples from 4 pharmacists. Surface contamination was assessed by the wiping test. Four of 6 wipe samples collected before PhaSeal indicated a detectable level of cyclophosphamide. About 7 months after the initiation of PhaSeal, only one of 6 wipe samples indicated a detectable level of cyclophosphamide. Although all 4 employees who provided urine samples had positive results for the urinary excretion of cyclophosphamide before PhaSeal, these levels returned to minimal levels in 2 pharmacists after PhaSeal. In combination with the biological safety cabinet and cleaning according to the Japanese guidelines, PhaSeal further reduces surface contamination and healthcare providers exposure to cyclophosphamide to almost undetectable levels.

Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques using RDX and C-4

DOE Office of Scientific and Technical Information (OSTI.GOV)

C.J. Miller; T.S. Yoder

The amount of time that an explosive is present on the surface of a material is dependent upon the original amount of explosive on the surface, temperature, humidity, rain, etc. This laboratory study focused on looking at similarities and differences in three different surface contamination techniques that are used when performance testing explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples. The three techniques used were dry transfer deposition of solutions using the Transportation Security Laboratory (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards, andmore » fingerprinting of actual explosives. Explosives were deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each surface type using each contamination technique. The surface types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, and metal obtained from a car hood at a junk yard. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal, oil and dirt. The substrates were photographed using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera to determine the difference in the crystalline structure and surface contamination in an attempt to determine differences and similarities associated with current contamination techniques.« less

Relationship of land uses with occurrence of contaminants of emerging concern in streams of southeastern Minnesota

USDA-ARS?s Scientific Manuscript database

Endocrine disrupting compounds (EDC), pharmaceuticals, and other contaminants of emerging concern (CEC) have been detected in surface waters, including compounds suspected or known to cause adverse human or ecological effects. Goals of the project are to (1) characterize CEC profiles and land uses a...

Detecting changes in the spatial distribution of nitrate contamination in ground water

USGS Publications Warehouse

Liu, Z.-J.; Hallberg, G.R.; Zimmerman, D.L.; Libra, R.D.

1997-01-01

Many studies of ground water pollution in general and nitrate contamination in particular have often relied on a one-time investigation, tracking of individual wells, or aggregate summaries. Studies of changes in spatial distribution of contaminants over time are lacking. This paper presents a method to compare spatial distributions for possible changes over time. The large-scale spatial distribution at a given time can be considered as a surface over the area (a trend surface). The changes in spatial distribution from period to period can be revealed by the differences in the shape and/or height of surfaces. If such a surface is described by a polynomial function, changes in surfaces can be detected by testing statistically for differences in their corresponding polynomial functions. This method was applied to nitrate concentration in a population of wells in an agricultural drainage basin in Iowa, sampled in three different years. For the period of 1981-1992, the large-scale spatial distribution of nitrate concentration did not show significant change in the shape of spatial surfaces; while the magnitude of nitrate concentration in the basin, or height of the computed surfaces showed significant fluctuations. The change in magnitude of nitrate concentration is closely related to climatic variations, especially in precipitation. The lack of change in the shape of spatial surfaces means that either the influence of land use/nitrogen management was overshadowed by climatic influence, or the changes in land use/management occurred in a random fashion.

Portable spotter for fluorescent contaminants on surfaces

DOEpatents

Schuresko, Daniel D.

1980-01-01

A portable fluorescence-based spotter for polynuclear aromatic hydrocarbon contamination on personnel and work area surfaces under ambient lighting conditions is provided. This instrument employs beam modulation and phase sensitive detection for discriminating between fluorescence from organic materials from reflected background light and inorganic fluorescent material. The device uses excitation and emission filters to provide differentiation between classes of aromatic organic compounds. Certain inorganic fluorescent materials, including heavy metal compounds, may also be distinguished from the organic compounds, despite both having similar optical properties.

A comparative review of optical surface contamination assessment techniques

NASA Technical Reports Server (NTRS)

Heaney, James B.

1987-01-01

This paper will review the relative sensitivities and practicalities of the common surface analytical methods that are used to detect and identify unwelcome adsorbants on optical surfaces. The compared methods include visual inspection, simple reflectometry and transmissiometry, ellipsometry, infrared absorption and attenuated total reflectance spectroscopy (ATR), Auger electron spectroscopy (AES), scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS), and mass accretion determined by quartz crystal microbalance (QCM). The discussion is biased toward those methods that apply optical thin film analytical techniques to spacecraft optical contamination problems. Examples are cited from both ground based and in-orbit experiments.

Contamination and Optics Degradation as Related to an Evolving Mission Design for the Terrestrial Planet Finder

NASA Astrophysics Data System (ADS)

Sharma, P. K.; Lindensmith, C. A.

1998-12-01

Terrestrial Planet Finder (TPF) is an evolving mission in NASA's ORIGINS program designed to detect earth like planets and perform high-resolution interferometric imaging of astrophysics targets in the infrared. The planet detection concept involves the use of multiple collectors in formation flying spacecraft and nulling interferometry to isolate the image of the planet (located near a bright star) while the star image is canceled out. The concept development involves the search for 10 to 20 micron radiation from planets orbiting stars out to a distance of 3 to 15 pc using NGST type collectors passively cooled to 35 K with high quality thermal shields. The need to obtain a suitable null for planet detection results in strict requirements of signal amplitude and phase matching at the optics. This in turn implies very tight cleanliness requirements at the optics. Several contamination issues need to be taken into account in order to maintain the integrity of the optics as well as the thermal shields. Cryogenic optical surfaces, e.g., mirror surfaces, are susceptible to contamination due to formation of thin cryolayers from propulsion system exhaust and outgassing products. Detector optics at 5 to 7 K will condense almost all species with the exception of hydrogen and helium. Thermal control surfaces at 35 to 40 K will condense a host of species including water vapor, which because of the presence of several absorption peaks in the infrared, will increase the emissivity of low emissivity surfaces. The increased emissivity will result in a temperature rise for the surface which will lead to decreased performance of cryocoolers, which depend upon passive precooling of the working fluid, used to cool the detectors. The condensed contaminant film on optics will also increase non-specular reflection from the surface, i.e., an increase in Bi-directional Reflectance Distribution Function (BRDF), leading to a lowering of the image quality. Particles on optical surfaces also increase scatter and thus the surface BRDF. This results in an increase in straylight. In addition, the surface particle induced scatter will reduce the contrast of the dark rings of the Point Spread Function (PSF) and hence make separation of a fainter celestial object situated near a brighter object more difficult. Warm particles in the field-of-view of the sensors can be mistaken for a celestial body due to their thermal emission. Similarly, certain contaminant molecules in the field-of-view of the sensors can mimic the sought spectral signatures of the terrestrial type planet. Contamination is an important consideration in the development of the TPF and continued study will help to minimize its effects on the mission.

Combined steam-ultrasound treatment of 2 seconds achieves significant high aerobic count and Enterobacteriaceae reduction on naturally contaminated food boxes, crates, conveyor belts, and meat knives.

PubMed

Musavian, Hanieh S; Butt, Tariq M; Larsen, Annette Baltzer; Krebs, Niels

2015-02-01

Food contact surfaces require rigorous sanitation procedures for decontamination, although these methods very often fail to efficiently clean and disinfect surfaces that are visibly contaminated with food residues and possible biofilms. In this study, the results of a short treatment (1 to 2 s) of combined steam (95°C) and ultrasound (SonoSteam) of industrial fish and meat transportation boxes and live-chicken transportation crates naturally contaminated with food and fecal residues were investigated. Aerobic counts of 5.0 to 6.0 log CFU/24 cm(2) and an Enterobacteriaceae spp. level of 2.0 CFU/24 cm(2) were found on the surfaces prior to the treatment. After 1 s of treatment, the aerobic counts were significantly (P < 0.0001) reduced, and within 2 s, reductions below the detection limit (<10 CFU) were reached. Enterobacteriaceae spp. were reduced to a level below the detection limit with only 1 s of treatment. Two seconds of steam-ultrasound treatment was also applied on two different types of plastic modular conveyor belts with hinge pins and one type of flat flexible rubber belt, all visibly contaminated with food residues. The aerobic counts of 3.0 to 5.0 CFU/50 cm(2) were significantly (P < 0.05) reduced, while Enterobacteriaceae spp. were reduced to a level below the detection limit. Industrial meat knives were contaminated with aerobic counts of 6.0 log CFU/5 cm(2) on the handle and 5.2 log CFU/14 cm(2) on the steel. The level of Enterobacteriaceae spp. contamination was approximately 2.5 log CFU on the handle and steel. Two seconds of steam-ultrasound treatment reduced the aerobic counts and Enterobacteriaceae spp. to levels below the detection limit on both handle and steel. This study shows that the steam-ultrasound treatment may be an effective replacement for disinfection processes and that it can be used for continuous disinfection at fast process lines. However, the treatment may not be able to replace efficient cleaning processes used to remove high loads of debris.

Assessing hog lagoon waste contamination in the Cape Fear Watershed using Bacteroidetes 16S rRNA gene pyrosequencing.

PubMed

Arfken, Ann M; Song, Bongkeun; Mallin, Michael A

2015-09-01

Hog lagoons can be major sources of waste and nutrient contamination to watersheds adjacent to pig farms. Fecal source tracking methods targeting Bacteroidetes 16S rRNA genes in pig fecal matter may underestimate or fail to detect hog lagoon contamination in riverine environments. In order to detect hog lagoon wastewater contamination in the Cape Fear Watershed, where a large number of hog farms are present, we conducted pyrosequencing analyses of Bacteroidetes 16S rRNA genes in hog lagoon waste and identified new hog lagoon-specific marker sequences. Additional pyrosequencing analyses of Bacteroidetes 16S rRNA genes were conducted with surface water samples collected at 4 sites during 5 months in the Cape Fear Watershed. Using an operational taxonomic unit (OTU) identity cutoff value of 97 %, these newly identified hog lagoon markers were found in 3 of the river samples, while only 1 sample contained the pig fecal marker. In the sample containing the pig fecal marker, there was a relatively high percentage (14.1 %) of the hog lagoon markers and a low pig fecal marker relative abundance of 0.4 % in the Bacteroidetes 16S rRNA gene sequences. This suggests that hog lagoon contamination must be somewhat significant in order for pig fecal markers to be detected, and low levels of hog lagoon contamination cannot be detected targeting only pig-specific fecal markers. Thus, new hog lagoon markers have a better detection capacity for lagoon waste contamination, and in conjunction with a pig fecal marker, provide a more comprehensive and accurate detection of hog lagoon waste contamination in susceptible watersheds.

Detection of microbial contamination during human islet isolation.

PubMed

Kin, Tatsuya; Rosichuk, Shawn; Shapiro, A M James; Lakey, Jonathan R T

2007-01-01

Current good manufacturing practice (cGMP) islet processing facilities provide an ultraclean environment for the safe production of clinical grade islets for transplantation into immunosuppressed diabetic recipients. The objective of this study was to monitor the rate of microbial contamination in islet products after implementation of good manufacturing practice conditions. Fluid samples for microbial contamination were collected at the following steps: from the pancreas transport solution upon arrival of the organ (n=157), after surface decontamination of the pancreas with antiseptic agents (n=89), from islet supernatant at the end of the isolation (n=104), and from islet supernatant as a final transplantable product after culture (n=53). Bacterial, fungal, and mycoplasma cultures were conducted for 2, 2, and 3 weeks, respectively. Microbial contamination was detected in 31% of transport solution. The contamination was not associated with the presence of the duodenum during the preservation, cold ischemia time, or procurement team (local vs. distant). Surface decontamination of the pancreas resulted in clearance of 92% of the microbial contamination. Six preparations at the end of the isolation revealed microbial growth. All were de novo contamination during the processing. Fifty-three preparations that met our release criteria in terms of product sterility were transplanted into type 1 diabetic patients. In two instances, positive culture of the islet preparation was reported after transplantation had occurred. No patient showed any clinical findings suggestive of infection or any radiological abnormalities suggestive of abscess; a single dose of antibiotic coverage was given routinely to recipients prior to islet infusion. Although transport solution carries a high risk of microbial contamination, most contaminants become undetectable during islet processing. Microbial contamination in final products is rare, but de novo contamination still occurs during processing even under cGMP conditions.

Detection of Microbial Contamination during Human Islet Isolation.

PubMed

Kin, Tatsuya; Rosichuk, Shawn; Shapiro, A M James; Lakey, Jonathan R T

2007-01-01

Current good manufacturing practice (cGMP) islet processing facilities provide an ultraclean environment for the safe production of clinical grade islets for transplantation into immunosuppressed diabetic recipients. The objective of this study was to monitor the rate of microbial contamination in islet products after implementation of good manufacturing practice conditions. Fluid samples for microbial contamination were collected at the following steps: from the pancreas transport solution upon arrival of the organ (n = 157), after surface decontamination of the pancreas with antiseptic agents (n = 89), from islet supernatant at the end of the isolation (n = 104), and from islet supernatant as a final transplantable product after culture (n = 53). Bacterial, fungal, and mycoplasma cultures were conducted for 2, 2, and 3 weeks, respectively. Microbial contamination was detected in 31% of transport solution. The contamination was not associated with the presence of the duodenum during the preservation, cold ischemia time, or procurement team (local vs. distant). Surface decontamination of the pancreas resulted in clearance of 92% of the microbial contamination. Six preparations at the end of the isolation revealed microbial growth. All were de novo contamination during the processing. Fifty-three preparations that met our release criteria in terms of product sterility were transplanted into type 1 diabetic patients. In two instances, positive culture of the islet preparation was reported after transplantation had occurred. No patient showed any clinical findings suggestive of infection or any radiological abnormalities suggestive of abscess; a single dose of antibiotic coverage was given routinely to recipients prior to islet infusion. Although transport solution carries a high risk of microbial contamination, most contaminants become undetectable during islet processing. Microbial contamination in final products is rare, but de novo contamination still occurs during processing even under cGMP conditions.

Contact angle determination procedure and detection of an invisible surface film

NASA Technical Reports Server (NTRS)

Meyer, G.; Grat, R.

1990-01-01

The contact angle value, i.e., the tangent angle of liquid resting on a planar solid surface, is a basic parameter which can be applied to a wide range of applications. The goal is to provide a basic understanding of the contact angle measurement technique and to present a simple illustration that can be applied as a quality control method; namely, detection of a surface contaminant which exists on a surface that appears clean to the unaided eye. The equipment and experimental procedures are detailed.

Widespread occurrence and potential for biodegradation of bioactive contaminants in Congaree National Park, USA.

PubMed

Bradley, Paul M; Battaglin, William A; Clark, Jimmy M; Henning, Frank P; Hladik, Michelle L; Iwanowicz, Luke R; Journey, Celeste A; Riley, Jeffrey W; Romanok, Kristin M

2017-11-01

Organic contaminants with designed molecular bioactivity, such as pesticides and pharmaceuticals, originate from human and agricultural sources, occur frequently in surface waters, and threaten the structure and function of aquatic and terrestrial ecosystems. Congaree National Park in South Carolina (USA) is a vulnerable park unit due to its location downstream of multiple urban and agricultural contaminant sources and its hydrologic setting, being composed almost entirely of floodplain and aquatic environments. Seventy-two water and sediment samples were collected from 16 sites in Congaree National Park during 2013 to 2015, and analyzed for 199 and 81 targeted organic contaminants, respectively. More than half of these water and sediment analytes were not detected or potentially had natural sources. Pharmaceutical contaminants were detected (49 total) frequently in water throughout Congaree National Park, with higher detection frequencies and concentrations at Congaree and Wateree River sites, downstream from major urban areas. Forty-seven organic wastewater indicator chemicals were detected in water, and 36 were detected in sediment, of which approximately half are distinctly anthropogenic. Endogenous sterols and hormones, which may originate from humans or wildlife, were detected in water and sediment samples throughout Congaree National Park, but synthetic hormones were detected only once, suggesting a comparatively low risk of adverse impacts. Assessment of the biodegradation potentials of 8 14 C-radiolabeled model contaminants indicated poor potentials for some contaminants, particularly under anaerobic sediments conditions. Environ Toxicol Chem 2017;36:3045-3056. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. © 2017 SETAC.

Preliminary study on detection sediment contamination in soil affected by the Indian Ocean giant tsunami 2004 in Aceh, Indonesia using laser-induced breakdown spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Idris, Nasrullah, E-mail: nasrullah.idris@unsyiah.ac.id; Ramli, Muliadi; Hedwig, Rinda

This work is intended to asses the capability of LIBS for the detection of the tsunami sediment contamination in soil. LIBS apparatus used in this work consist of a laser system and an optical multichannel analyzer (OMA) system. The soil sample was collected from in Banda Aceh City, Aceh, Indonesia, the most affected region by the giant Indian Ocean tsunami 2004. The laser beam was focused onto surface of the soil pellet using a focusing lens to produce luminous plasma. The experiment was conducted under air as surrounding gas at 1 atmosphere. The emission spectral lines from the plasma weremore » detected by the OMA system. It was found that metal including heavy metals can surely be detected, thus implying the potent of LIBS technique as a fast screening tools of tsunami sediment contamination.« less

Transmission of SARS and MERS coronaviruses and influenza virus in healthcare settings: the possible role of dry surface contamination.

PubMed

Otter, J A; Donskey, C; Yezli, S; Douthwaite, S; Goldenberg, S D; Weber, D J

2016-03-01

Viruses with pandemic potential including H1N1, H5N1, and H5N7 influenza viruses, and severe acute respiratory syndrome (SARS)/Middle East respiratory syndrome (MERS) coronaviruses (CoV) have emerged in recent years. SARS-CoV, MERS-CoV, and influenza virus can survive on surfaces for extended periods, sometimes up to months. Factors influencing the survival of these viruses on surfaces include: strain variation, titre, surface type, suspending medium, mode of deposition, temperature and relative humidity, and the method used to determine the viability of the virus. Environmental sampling has identified contamination in field-settings with SARS-CoV and influenza virus, although the frequent use of molecular detection methods may not necessarily represent the presence of viable virus. The importance of indirect contact transmission (involving contamination of inanimate surfaces) is uncertain compared with other transmission routes, principally direct contact transmission (independent of surface contamination), droplet, and airborne routes. However, influenza virus and SARS-CoV may be shed into the environment and be transferred from environmental surfaces to hands of patients and healthcare providers. Emerging data suggest that MERS-CoV also shares these properties. Once contaminated from the environment, hands can then initiate self-inoculation of mucous membranes of the nose, eyes or mouth. Mathematical and animal models, and intervention studies suggest that contact transmission is the most important route in some scenarios. Infection prevention and control implications include the need for hand hygiene and personal protective equipment to minimize self-contamination and to protect against inoculation of mucosal surfaces and the respiratory tract, and enhanced surface cleaning and disinfection in healthcare settings. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

CURRENT ISSUES IN HTE DETECTION OF HUMAN EXPOSURE TO THE CYANOBACTERIA TOXINS, MICROCYSTINS

EPA Science Inventory

Introduction: Toxic cyanobacteria are contaminants of surface waters worldwide. Microcystins are some of the most commonly detected toxins. Biological evidence of human exposure has been difficult to obtain due to technical, temporal, and biological limitations. However, evide...

Occurrence of pesticides and contaminants of emerging concern in surface waters: Influence of surrounding land use and evaluation of sampling methods

USDA-ARS?s Scientific Manuscript database

Biologically active compounds originating from agricultural, residential, and industrial sources have been detected in surface waters, which have invoked concern of their potential ecological and human health effects. Automated and grab surface water samples, passive water samples - Polar Organic Co...

Detection of mitochondrial DNA with the compact bead array sensor system (cBASS)

NASA Astrophysics Data System (ADS)

Mulvaney, Shawn P.; Ibe, Carol N.; Caldwell, Jane M.; Levine, Jay F.; Whitman, Lloyd J.; Tamanaha, Cy R.

2009-02-01

Enteric pathogens are a significant contaminant in surface waters used for recreation, fish and shellfish harvesting, crop irrigation, and human consumption. The need for water monitoring becomes more pronounced when industrial, agricultural, and residential lands are found in close proximity. Fecal contamination is particularly problematic and identification of the pollution source essential to remediation efforts. Standard monitoring for fecal contamination relies on indicator organisms, but the technique is too broad to identify the source of contamination. Instead, real-time PCR of mitochondrial DNA (mtDNA) is an emerging method for identification of the contamination source. Presented herein, we evaluate an alternative technology, the compact Bead Array Sensor System (cBASS®) and its assay approach Fluidic Force Discrimination (FFD), for the detection of mtDNA. Previously, we achieved multiplexed, attomolar detection of toxins and femtomolar detection of nucleic acids in minutes with FFD assays. More importantly, FFD assays are compatible with a variety of complex matrices and therefore potentially applicable for samples where the matrix would interfere with PCR amplification. We have designed a triplex assay for the NADH gene found in human, swine, and bovine mtDNA and demonstrated the specific detection of human mtDNA spiked into a waste water sample.

Potential of groundwater contamination by polybrominated diphenyl ethers (PBDEs) in a sensitive bedrock aquifer (Canada)

NASA Astrophysics Data System (ADS)

Levison, Jana; Novakowski, Kent; Reiner, Eric J.; Kolic, Terry

2012-03-01

It is necessary to understand the presence, movement, and persistence of contaminants in aquifers to develop adequate groundwater protection plans. Fractured bedrock aquifers with thin overburden cover are very sensitive to contamination, and little is known about transport processes from the ground surface to depth in this setting. This study was undertaken to investigate the potential of groundwater contamination by polybrominated diphenyl ethers (PBDEs), which are flame retardants, in a natural fractured bedrock aquifer in Canada proven to be sensitive to contamination. PBDEs, which had not been previously measured in groundwater in detail, were detected in the study aquifer at concentrations greater than those observed in surface-water bodies. Potential sources include manure, septic tanks, and the atmosphere. From this scoping study, it is evident that additional surveys of PBDE concentrations in groundwater are warranted, especially in settings with high potential source concentrations coupled with sensitive aquifers.

Estimating the susceptibility of surface water in Texas to nonpoint-source contamination by use of logistic regression modeling

USGS Publications Warehouse

Battaglin, William A.; Ulery, Randy L.; Winterstein, Thomas; Welborn, Toby

2003-01-01

In the State of Texas, surface water (streams, canals, and reservoirs) and ground water are used as sources of public water supply. Surface-water sources of public water supply are susceptible to contamination from point and nonpoint sources. To help protect sources of drinking water and to aid water managers in designing protective yet cost-effective and risk-mitigated monitoring strategies, the Texas Commission on Environmental Quality and the U.S. Geological Survey developed procedures to assess the susceptibility of public water-supply source waters in Texas to the occurrence of 227 contaminants. One component of the assessments is the determination of susceptibility of surface-water sources to nonpoint-source contamination. To accomplish this, water-quality data at 323 monitoring sites were matched with geographic information system-derived watershed- characteristic data for the watersheds upstream from the sites. Logistic regression models then were developed to estimate the probability that a particular contaminant will exceed a threshold concentration specified by the Texas Commission on Environmental Quality. Logistic regression models were developed for 63 of the 227 contaminants. Of the remaining contaminants, 106 were not modeled because monitoring data were available at less than 10 percent of the monitoring sites; 29 were not modeled because there were less than 15 percent detections of the contaminant in the monitoring data; 27 were not modeled because of the lack of any monitoring data; and 2 were not modeled because threshold values were not specified.

Contamination of X-ray Cassettes with Methicillin-resistant Staphylococcus aureus and Methicillin-resistant Staphylococcus haemolyticus in a Radiology Department

PubMed Central

Kim, Han-Sung; Park, Ji-Young; Koo, Hyun-Sook; Choi, Chul-Sun; Song, Wonkeun; Cho, Hyoun Chan; Lee, Kyu Man

2012-01-01

Background We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA). Methods The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 µg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing. Pulsed-field gel electrophoresis (PFGE) analysis was performed to determine the clonal relationships of the contaminants. Results Six X-ray cassettes (16.2%) were contaminated with MRSA. During the isolation procedure, we also detected 19 X-ray cassettes (51.4%) contaminated with methicillin-resistant Staphylococcus haemolyticus (MRSH), identified as yellow colonies resembling MRSA on mannitol salt agar. PFGE analysis of the MRSA and MRSH isolates revealed that most isolates of each organism were identical or closely related to each other, suggesting a common source of contamination. Conclusions X-ray cassettes, which are commonly in direct contact with patients, were contaminated with MRSA and MRSH. In hospital environments, contaminated X-ray cassettes may serve as fomites for methicillin-resistant staphylococci. PMID:22563556

Contamination of X-ray cassettes with methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus haemolyticus in a radiology department.

PubMed

Kim, Jae-Seok; Kim, Han-Sung; Park, Ji-Young; Koo, Hyun-Sook; Choi, Chul-Sun; Song, Wonkeun; Cho, Hyoun Chan; Lee, Kyu Man

2012-05-01

We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA). The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 µg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing. Pulsed-field gel electrophoresis (PFGE) analysis was performed to determine the clonal relationships of the contaminants. Six X-ray cassettes (16.2%) were contaminated with MRSA. During the isolation procedure, we also detected 19 X-ray cassettes (51.4%) contaminated with methicillin-resistant Staphylococcus haemolyticus (MRSH), identified as yellow colonies resembling MRSA on mannitol salt agar. PFGE analysis of the MRSA and MRSH isolates revealed that most isolates of each organism were identical or closely related to each other, suggesting a common source of contamination. X-ray cassettes, which are commonly in direct contact with patients, were contaminated with MRSA and MRSH. In hospital environments, contaminated X-ray cassettes may serve as fomites for methicillin-resistant staphylococci.

Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning and household bleach.

PubMed

Kusumaningrum, H D; Paltinaite, R; Koomen, A J; Hazeleger, W C; Rombouts, F M; Beumer, R R

2003-12-01

Effective cleaning and sanitizing of food preparation sites is important because pathogens are readily spread to food contact surfaces after preparation of contaminated raw products. Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning by wiping with regular, microfiber, and antibacterial-treated cloths was investigated. Wiping with cleaning cloths resulted in a considerable reduction of microorganisms from surfaces, despite the greater difficulty in removing S. aureus than Salmonella Enteritidis. Depending on the cloth type, S. aureus were reduced on surfaces from initial numbers of approximately 10(5) CFU/100 cm2 to numbers from less than 4 CFU/100 cm2 (below the detection limit) to 100 CFU/100 cm2. Directly after the cloths were used to clean the contaminated surfaces, they contained high numbers of bacteria (10(4) to 10(5) CFU/100 cm2), except for the disposable antibacterial-treated cloths, in which no bacteria could be detected. The tolerance of these pathogens to sodium hypochlorite was studied in the suspension test and in cloths. S. aureus showed a better tolerance for sodium hypochlorite than Salmonella Enteritidis. Inactivation of microorganisms in cloths required a higher concentration of sodium hypochlorite than was needed in the suspension test. Repeated exposure to sodium hypochlorite, however, resulted in an increase in susceptibility to this compound. This study provides essential information about the transfer of bacteria when wiping surfaces and highlights the need for a hygiene procedure with cleaning cloths that sufficiently avoids cross-contamination in the household environment.

Phyt'Eaux Cités: application and validation of a programme to reduce surface water contamination with urban pesticides.

PubMed

Botta, Fabrizio; Fauchon, Nils; Blanchoud, Hélène; Chevreuil, Marc; Guery, Bénédicte

2012-01-01

This paper presents first results of Phyt'Eaux Cités, a program put in place by the local water supply agency, the SEDIF (Syndicat des Eaux d'Ile-de-France), in collaboration with 73 local authorities, private societies and institutional offices (365 km(2)). The challenges included: measurement of the previous surface water contamination, control of urban pesticide applications, prevention of pesticide hazard on users and finally a overall reduction of surface water contamination. An inquiry on urban total pesticide amount was coupled with a surface water bi-weekly monitoring to establish the impact of more than 200 molecules upon the Orge River. For 2007, at least 4400 kg and 92 type of pesticides (essentially herbicides) were quantified for all urban users in the Phyt'Eaux Cités perimeter. At the outlet of the Orge River (bi-weekly sampling in 2007), 11 molecules were always detected above 0.1 μg L(-1). They displayed the mainly urban origin of pesticide surface water contamination. Amitrole, AMPA (Aminomethyl Phosphonic Acid), demethyldiuron, diuron, glyphosate and atrazine were quantified with a 100% of frequency in 2007 and 2008 at the Orge River outlet. During the year, peaks of contamination were also registered for MCCP, 2,4 MCPA, 2,4 D, triclopyr, dichlorprop, diflufènican, active substances used in large amount in the urban area. However, some other urban molecules, such as isoxaben or flazasulfuron, were detected with low frequency. During late spring and summer, contamination patterns and load were dominated by glyphosate, amitrole and diuron, essentially applied by cities and urban users. Both isoproturon and chlortoluron were quantified during autumn and winter months according to upstream agricultural practices. In conclusion, 3 years after the beginning of this programme, the cities reduced the use of 68% of the total pesticide amount. An improvement on surface water quality was found from 2008 and during 2009 for all pesticides. In particular, glyphosate showed a decrease of the load above 60% in 2008, partly related to the Phyt'Eaux Cités action. Copyright © 2011 Elsevier Ltd. All rights reserved.

Monitoring of biofilm formation on different material surfaces of medical devices using hyperspectral imaging method

NASA Astrophysics Data System (ADS)

Kim, Do-Hyun; Kim, Moon S.; Hwang, Jeeseong

2012-03-01

Contamination of the inner surface of indwelling (implanted) medical devices by microbial biofilm is a serious problem. Some microbial bacteria such as Escherichia coli form biofilms that lead to potentially lifethreatening infections. Other types of medical devices such as bronchoscopes and duodenoscopes account for the highest number of reported endoscopic infections where microbial biofilm is one of the major causes for these infections. We applied a hyperspectral imaging method to detect biofilm contamination on the surface of several common materials used for medical devices. Such materials include stainless steel, titanium, and stainless-steeltitanium alloy. Potential uses of hyperspectral imaging technique to monitor biofilm attachment to different material surfaces are discussed.

Pilot Plant Testing of Hot Gas Building Decontamination Process

DTIC Science & Technology

1987-10-30

last hours of the cooldown (after water traps in the line were installed) showed no detectable contamination from this station. 1 60 CwC -So 0) 0 o j...Since we will not require refrigeration, additional generators probably 0 qlill not be required. Water is trucked to the site. Agent contaminated water ...surface. The gauze was handled by forceps during all of the sampling steps to prevent contamination after the solvent extraction clean-up of the gauze pads

Health assessment for Ninth Avenue Dump National Priorities List (NPL) Site, Gary, Indiana, Region 5. CERCLIS No. IND980794432. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-01-18

The Ninth Avenue Dump is a 17-acre National Priorities List Site located in an industrialized area within the city limits of Gary, Indiana. A number of contaminants were detected in on-site and off-site ground water, surface water, sediments, and soil samples. Contaminants of concern at the Ninth Avenue Dump Site include: chromium, lead, benzene, polychlorinated biphenyls, 2-butanone, ethylbenzene, toluene, trichloroethylene, vinyl chloride, and xylenes. The pathways for human exposure to site contaminants is through the dermal absorption, ingestion, or inhalation of contaminants from ground water, surface water, soil, air, or contaminated food-chain entities. There is currently no documented exposure tomore » site contaminants. However, the site is considered to be of potential public health concern because of the potential risk to human health resulting from possible exposure to hazardous substances at concentrations that may result in adverse health effects.« less

Resistance of Pseudomonas aeruginosa to liquid disinfectants on contaminated surfaces before formation of biofilms.

PubMed

Sagripanti, J L; Bonifacino, A

2000-01-01

A comparison was made of the effectiveness of popular disinfectants (Cavicide, Cidexplus, Clorox, Exspor, Lysol, Renalin, and Wavicide) under conditions prescribed for disinfection in the respective product labels on Pseudomonas aeruginosa either in suspension or deposited onto surfaces of metallic or polymeric plastic devices. The testing also included 7 nonformulated germicidal agents (glutaraldehyde, formaldehyde, peracetic acid, hydrogen peroxide, sodium hypochlorite, phenol, and cupric ascorbate) commonly used in disinfection and decontamination. Results showed that P. aeruginosa is on average 300-fold more resistant when present on contaminated surfaces than in suspension. This increase in resistance agrees with results reported in studies of biofilms, but unexpectedly, it precedes biofilm formation. The surface to which bacteria are attached can influence the effectiveness of disinfectants. Viable bacteria attached to devices may require dislodging through more than a one-step method for detection. The data, obtained with a sensitive and quantitative test, suggest that disinfectants are less effective on contaminated surfaces than generally acknowledged.

Four methods for determining the composition of trace radioactive surface contamination of low-radioactivity metal

NASA Astrophysics Data System (ADS)

O'Keeffe, H. M.; Burritt, T. H.; Cleveland, B. T.; Doucas, G.; Gagnon, N.; Jelley, N. A.; Kraus, C.; Lawson, I. T.; Majerus, S.; McGee, S. R.; Myers, A. W.; Poon, A. W. P.; Rielage, K.; Robertson, R. G. H.; Rosten, R. C.; Stonehill, L. C.; VanDevender, B. A.; Van Wechel, T. D.

2011-12-01

Four methods for determining the composition of low-level uranium- and thorium-chain surface contamination are presented. One method is the observation of Cherenkov light production in water. In two additional methods a position-sensitive proportional counter surrounding the surface is used to make both a measurement of the energy spectrum of alpha particle emissions and also coincidence measurements to derive the thorium-chain content based on the presence of short-lived isotopes in that decay chain. The fourth method is a radiochemical technique in which the surface is eluted with a weak acid, the eluate is concentrated, added to liquid scintillator and assayed by recording beta-alpha coincidences. These methods were used to characterize two 'hotspots' on the outer surface of one of the 3He proportional counters in the Neutral Current Detection array of the Sudbury Neutrino Observatory experiment. The methods have similar sensitivities, of order tens of ng, to both thorium- and uranium-chain contamination.

A SIMPLE COLORIMETRIC METHOD TO DETECT BIOLOGICAL EVIDENCE OF HUMAN EXPOSURE TO MICROCYSTINS

EPA Science Inventory

Toxic cyanobacteria are contaminants of surface waters worldwide. Microcystins are some of the most commonly detected toxins. Biological evidence of human exposure may be difficult to obtain due to limitations associated with cost, laboratory capacity, analytic support, and exp...

Environmental and biological monitoring of platinum-containing drugs in two hospital pharmacies using positive air pressure isolators.

PubMed

Kopp, Bettina; Crauste-Manciet, Sylvie; Guibert, Agnès; Mourier, Wilhelmine; Guerrault-Moro, Marie-Noelle; Ferrari, Sylvie; Jomier, Jean-Yves; Brossard, Denis; Schierl, Rudolf

2013-04-01

Environmental and biological monitoring of platinum containing drugs was implemented in two French hospital pharmacies using positive air pressure isolators and having similar working procedures when preparing antineoplastic drugs. Wipe sampling of surfaces, gloves, and vials was performed in the preparation room and in storage areas. All employees involved in the preparation of antineoplastic drugs were tested for urinary platinum on Monday before work and Friday after shift. Only traces of platinum were detected on surfaces in the preparation room outside the isolators (less than 1.61 pg cm(-2)). However, in one center, significant contamination was found in the storage area of the drug vials, which can most likely be linked to the rupture of a platinum vial and due to inefficient cleaning procedures. Surfaces inside the isolators were found to be contaminated (maximum: 198.4 pg cm(-2)). A higher level of contamination was detected in one pharmacy and could be explained by the lack of overgloving with regular changes during the preparation process. Nitrile gloves used during drug handling outside the isolator showed the highest platinum concentration (maximum: 5.86 ng per pair). With regards to platinum urine concentration, no significant difference was found between exposed and unexposed pharmacy personnel. Isolator technology combined with individual protective measures seems to be efficient to protect workers from occupational exposure to antineoplastic drugs, whereas specific individual protective procedures implemented were focussing on the risk of handling vials outside the isolator (e.g. high frequency of glove changing). Moreover, overgloving inside the isolator would contribute to substantially decrease inner surface contamination and should be recommended in order to limit the transfer of chemical contamination to the end products.

Processing-Dependent and Clonal Contamination Patterns of Listeria monocytogenes in the Cured Ham Food Chain Revealed by Genetic Analysis

PubMed Central

Morganti, Marina; Scaltriti, Erika; Cozzolino, Paolo; Bolzoni, Luca; Casadei, Gabriele; Pierantoni, Marco; Foni, Emanuela

2015-01-01

The quantitative and qualitative patterns of environmental contamination by Listeria monocytogenes were investigated in the production chain of dry-cured Parma ham. Standard arrays of surfaces were sampled in processing facilities during a single visit per plant in the three compartments of the food chain, i.e., ham production (19 plants) and postproduction, which was divided into deboning (43 plants) and slicing (25 plants) steps. The numbers of sampled surfaces were 384 in ham production, with 25 positive for L. monocytogenes, and 1,084 in postproduction, with 83 positives. Statistical analysis of the prevalence of contaminated surfaces showed that in ham production, contamination was higher at the beginning of processing and declined significantly toward the end, while in postproduction, prevalence rose toward the end of processing. Prevalence was higher in the deboning facilities than in slicing facilities and was dependent on the type of surface (floor/drainage > clothing > equipment). The qualitative pattern of contamination was investigated through an analysis of the survey isolates and a set of isolates derived from routine monitoring, including longitudinal isolations. Pulsed-field gel electrophoresis (PFGE) and whole-genome single-nucleotide polymorphism (SNP) analysis revealed a remarkable clonality of L. monocytogenes within plants, with the detection of 16 plant-specific clones out of 17 establishments with multiple isolates. Repeated detections of clonal isolates >6 months apart were also observed. Six was the maximum number of between-isolate differences in core SNPs observed within these clones. Based on the same six-SNP threshold, three clusters of clonal isolates, shared by six establishments, were also identified. The spread of L. monocytogenes within and between plants, as indicated by its clonal behavior, is a matter of concern for the hygienic management of establishments. PMID:26590278

Simulation of internal contamination screening with dose rate meters

NASA Astrophysics Data System (ADS)

Fonseca, T. C. F.; Mendes, B. M.; Hunt, J. G.

2017-11-01

Assessing the intake of radionuclides after an accident in a nuclear power plant or after the intentional release of radionuclides in public places allows dose calculations and triage actions to be carried out for members of the public and for emergency response teams. Gamma emitters in the lung, thyroid or the whole body may be detected and quantified by making dose rate measurements at the surface of the internally contaminated person. In an accident scenario, quick measurements made with readily available portable equipment are a key factor for success. In this paper, the Monte Carlo program Visual Monte Carlo (VMC) and MCNPx code are used in conjunction with voxel phantoms to calculate the dose rate at the surface of a contaminated person due to internally deposited radionuclides. A whole body contamination with 137Cs and a thyroid contamination with 131I were simulated and the calibration factors in kBq per μSv/h were calculated. The calculated calibration factors were compared with real data obtained from the Goiania accident in the case of 137Cs and the Chernobyl accident in terms of the 131I. The close comparison of the calculated and real measurements indicates that the method may be applied to other radionuclides. Minimum detectable activities are discussed.

Prevalence of Rotavirus Genogroup A and Norovirus Genogroup II in Bassaseachic Falls National Park Surface Waters in Chihuahua, Mexico.

PubMed

Delgado-Gardea, Ma Carmen E; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Mendieta-Mendoza, Aurora; Zavala-Díaz de la Serna, Francisco Javier; Contreras-Cordero, Juan Francisco; Erosa-de la Vega, Gilberto; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, Carmen; Infante-Ramírez, Rocío

2017-05-05

In areas lacking potable water treatment, drinking contaminated water may represent a public health threat. In addition to enteropathogenic bacteria and parasites, fecal contamination in water environments is associated with the transmission of enteric viruses and other causal agents of infectious disease. Rotavirus and norovirus are the main enteric viral agents responsible for diarrheic outbreaks. The aim of the present study was to detect seasonal variation of rotavirus and norovirus in the surface water at Bassaseachic Falls National Park during 2013. Rivers and streams within and nearby this park were sampled once in each season during 2013. Viral concentration was carried out by a handmade filtration equipment, using a commercial electropositive membrane coupled with the virus absortion elution technique (VIRADEL©). Detection of rotavirus and norovirus was performed by SYBR Green reverse transcription-real time polymerase chain reaction (SYBR GREEN© RT-qPCR) analyses. Norovirus genogroup II was detected in samples collected in June and October 2013. In the case of rotavirus, genogroup A was detected in March and June. The presence of rotavirus and norovirus was related to viral acute diarrhea in children less than five years of age, who were inhabiting the sampled areas. This may indicates that the contaminated water was potentially a risk factor for regional diarrheic outbreaks.

Study to investigate the trace levels of contamination on surfaces when narcotic contraband is concealed in a vehicle

NASA Astrophysics Data System (ADS)

Wilson, Rod; Brittain, Alan H.

1997-01-01

When a vehicle is used to transport narcotic contraband material trace levels of that material can be found on surfaces of the vehicle, people associated with the vehicle and surface they contact. The detection of these trace levels can help to target vehicles associated with the smuggling of the contraband. A study to determine the typical levels of narcotic material that can be detected from these surfaces has been performed by personnel from Graseby, using a variety of drug materials. The size and packaging of the drug materials has been prepared to try to reflect that typically found in smuggling operations. These tests show that for all hard drugs easily detectable traces of drug material can be found on the vehicle, the proxy and secondary surfaces handled by the proxy. For detection of cannabis, the condition of the original material had a great bearing ont he reliability of detection.

2013 Survey of Iowa groundwater and evaluation of public well vulnerability classifications for contaminants of emerging concern

USGS Publications Warehouse

Hruby, Claire E.; Libra, Robert D.; Fields, Chad L.; Kolpin, Dana W.; Hubbard, Laura E.; Borchardt, Mark R.; Spencer, Susan K.; Wichman, Michael D.; Hall, Nancy; Schueller, Michael D.; Furlong, Edward T.; Weyer, Peter J.

2015-01-01

Studies in Iowa have long documented the vulnerability of wells with less than 50 feet (15 meters) of confining materials above the source aquifer to contamination from nitrate and various pesticides. Recent studies in Wisconsin have documented the occurrence of viruses in untreated groundwater, even in wells considered to have little vulnerability to contamination from near-surface activities. In addition, sensitive methods have become available for analyses of pharmaceuticals and pesticides. This study represents the first comprehensive examination of contaminants of emerging concern in Iowa’s groundwater conducted to date, and one of the first conducted in the United States. Raw groundwater samples were collected from 66 public supply wells during the spring of 2013, when the state was recovering from drought conditions. Samples were analyzed for 206 chemical and biological parameters; including 20 general water-quality parameters and major ions, 19 metals, 5 nutrients, 10 virus groups, 3 species of pathogenic bacteria, 5 microbial indicators, 108 pharmaceuticals, 35 pesticides and pesticide degradates, and tritium. The wells chosen for this study represent a diverse range of ages, depths, confining material thicknesses, pumping rates, and land use settings. The most commonly detected contaminant group was pesticide compounds, which were present in 41% of the samples. As many as 6 pesticide compounds were found together in a sample, most of which were chloroacetanilide degradates. While none of the measured concentrations of pesticide compounds exceeded current benchmark levels, several of these compounds are listed on the U.S. Environmental Protection Agency’s Contaminant Candidate List and could be subject to drinking water standards in the future. Despite heavy use in the past decade, glyphosate was not detected, and its metabolite, aminomethylphosphonic acid, was only detected in two of 60 wells tested (3%) at the detection limit of 0.02 μg/L. Pharmaceutical compounds were detected in 35% of 63 samples. Of the 14 pharmaceuticals detected, six had reported concentrations above the method reporting limit, with the maximum reported concentration of 826 ng/L for acetaminophen. Diphenhydramine was the only pharmaceutical to have two detections above the reporting limit, at 24.5 and 145 ng/L. Eight pharmaceuticals had confirmed detections at concentrations below the method reporting limit. Caffeine was the most frequently detected pharmaceutical compound (25%), followed by the caffeine metabolite, 1,7- dimethylxanthine (16%).  Microorganisms were detected in 21% of the wells using quantitative polymerase chain reaction methodologies. The most frequently detected microorganism was the pepper mild mottle virus (PMMV), a plant pathogen found in human waste. PMMV was detected in 17% of samples at concentrations ranging from 0.4 to 6.38 gene copies per liter. GII norovirus, human polyomavirus, bovine polyomavirus, and Campylobacter were also detected, while adenovirus, enterovirus, GI norovirus, swine hepatitis E, Salmonella, and enterohemmorhagic E. coli were not detected. No correlations were found between viruses or pathogenic bacteria and microbial indicators. Wells with less than 50 feet (15 meters) of confining material were shown to have greater incidence of surface-related contaminants; however, significant relationships (p<0.05) between confining layer thickness and contaminants were only found for nitrate and herbicides.

Detection and mapping of trace explosives on surfaces under ambient conditions using multiphoton electron extraction spectroscopy (MEES).

PubMed

Tang, Shisong; Vinerot, Nataly; Fisher, Danny; Bulatov, Valery; Yavetz-Chen, Yehuda; Schechter, Israel

2016-08-01

Multiphoton electron extraction spectroscopy (MEES) is an analytical method in which UV laser pulses are utilized for extracting electrons from solid surfaces in multiphoton processes under ambient conditions. Counting the emitted electrons as a function of laser wavelength results in detailed spectral features, which can be used for material identification. The method has been applied to detection of trace explosives on a variety of surfaces. Detection was possible on dusty swabs spiked with explosives and also in the standard dry-transfer contamination procedure. Plastic explosives could also be detected. The analytical limits of detection (LODs) are in the sub pmole range, which indicates that MEES is one of the most sensitive detection methods for solid surface under ambient conditions. Scanning the surface with the laser allows for its imaging, such that explosives (as well as other materials) can be located. The imaging mode is also useful in forensic applications, such as detection of explosives in human fingerprints. Copyright © 2016 Elsevier B.V. All rights reserved.

Amyloid-specific fluorophores for the rapid, sensitive in situ detection of prion contamination on surgical instruments.

PubMed

Lipscomb, I P; Hervé, R; Harris, K; Pinchin, H; Collin, R; Keevil, C W

2007-09-01

Prion diseases or transmissible spongiform encephalopathies (TSEs) are a group of rare, transmissible and fatal neurodegenerative diseases associated with the protein agent (PrP(Sc)). As such, the sensitive and rapid detection of prion PrP(Sc) amyloid on the surface of suspect surgical instruments is of great importance and may even allow remedial action to be taken prior to any further operative intervention and possible iatrogenic transmission. However, conventional PrP(Sc) detection methodologies tend to rely on the inefficient and unreliable removal of suspect material from a surface using swabs or wipes prior to antibody analysis. Here we show how the combination of an advanced light microscope technique, episcopic differential interference contrast/epifluorescence (EDIC/EF) microscopy, and the application of beta-amyloid fluorescent thiazole markers (thioflavin T, thioflavin S) can be used to detect, in situ, submicron (attomole) levels of prion protein amyloid contamination in brain and spleen sections, smears and homogenate on surgical stainless steel surfaces and surgical instruments. This technique, although not specific to an amyloid type, can be used to verify that surgical instruments are substantially free from prion amyloid protein soiling and hence reduce the risk of iatrogenic transmission.

Fluorescence-Assisted Gamma Spectrometry for Surface Contamination Analysis

NASA Astrophysics Data System (ADS)

Ihantola, Sakari; Sand, Johan; Perajarvi, Kari; Toivonen, Juha; Toivonen, Harri

2013-02-01

A fluorescence-based alpha-gamma coincidence spectrometry approach has been developed for the analysis of alpha-emitting radionuclides. The thermalization of alpha particles in air produces UV light, which in turn can be detected over long distances. The simultaneous detection of UV and gamma photons allows detailed gamma analyses of a single spot of interest even in highly active surroundings. Alpha particles can also be detected indirectly from samples inside sealed plastic bags, which minimizes the risk of cross-contamination. The position-sensitive alpha-UV-gamma coincidence technique reveals the presence of alpha emitters and identifies the nuclides ten times faster than conventional gamma spectrometry.

Detection of human and animal sources of pollution by microbial and chemical methods

USDA-ARS?s Scientific Manuscript database

A multi-indicator approach comprising Enterococcus, bacterial source tracking (BST), and sterol analysis was tested for pollution source identification. Fecal contamination was detected in 100% of surface water sites tested. Enterococcus faecium was the dominant species in aged litter samples from p...

Description and hydrogeologic evaluation of nine hazardous-waste sites in Kansas, 1984-86

USGS Publications Warehouse

Hart, R.J.; Spruill, T.B.

1988-01-01

Wastes generated at nine hazardous-waste sites in Kansas were disposed in open pits, 55-gal drums, or large storage tanks. These disposal methods have the potential to contaminate groundwater beneath the sites, the soil on the sites, and nearby surface water bodies. Various activities on the nine sites included production of diborane, transformer oil waste, production of soda ash, use of solvents for the manufacture of farm implements, reclamation of solvents and paints, oil-refinery wastes, meat packaging, and the manufacture and cleaning of tanker-truck tanks. Monitoring wells were installed upgradient and downgradient from the potential contamination source on each site. Strict decontamination procedures were followed to prevent cross contamination between well installations. Air-quality surveys were made on each site before other investigative procedures started. Hydrogeologic investigative techniques, such as terrain geophysical surveys, gamma-ray logs, and laboratory permeameter tests, were used. Groundwater level measurements provide data to determine the direction of flow. Groundwater contamination detected under the sites posed the greatest threat to the environment because of possible migration of contaminants by groundwater flow. Concentrations of volatile organic compounds, polynuclear aromatic hydrocarbons, and trace metals were detected in the groundwater at several of the sites. Many of the same compounds detected in the groundwater also were detected in soil and bed-material samples collected onsite or adjacent to the sites. Several contaminants were detected in background samples of groundwater and soil. (USGS)

Development of a Loop Mediated Isothermal Amplification (LAMP) - Surface Enhanced Raman spectroscopy (SERS) Assay for the Detection of Salmonella Enterica Serotype Enteritidis.

PubMed

Draz, Mohamed Shehata; Lu, Xiaonan

2016-01-01

As a major foodborne pathogen, Salmonella enterica serotype Enteritidis is increasingly rising as a global health concern. Here, we developed an integrated assay that combines loop mediated isothermal amplification (LAMP) and surface enhanced Raman spectroscopy (SERS) for DNA detection of S. Enteritidis using specifically designed Raman active Au-nanoprobes. The target DNA was amplified by LAMP and then labeled with Au-nanoprobes comprised of gold nanoparticle-modified with specific cy5/DNA probes to allow the detection by SERS. The sensitivity of the developed LAMP-SERS detection assay (66 CFU/mL) was ~100-fold higher than the conventional polymerase chain reaction (PCR) method. Significantly, this technique allowed highly specific detection of the target DNA of S. Enteritidis and could differentiate it from the DNA of closely related bacterial species or non-specific contamination, making it more accurate and reliable than the standard LAMP technique. The applicability of detection of S. Enteritidis in milk samples using LAMP-SERS assay was validated as well. In sum, the developed LAMP-SERS assay is highly specific and sensitive, and has the potential to be applied for rapid detection of different foodborne pathogens and other microbial contaminants.

Organics in APOLLO Lunar Samples

NASA Technical Reports Server (NTRS)

Allen, C. C.; Allton, J. H.

2007-01-01

One of many unknowns prior to the Apollo landings concerned the possibility of life, its remains, or its organic precursors on the surface of the Moon. While the existence of lunar organisms was considered highly unlikely, a program of biological quarantine and testing for the astronauts, the Apollo Command Modules, and the lunar rock and soil samples, was instituted in the Lunar Receiving Laboratory (LRL). No conclusive evidence of lunar organisms, was detected and the quarantine program was ended after Apollo 14. Analyses for organic compounds were also con-ducted. Considerable effort was expended, during lunar surface operations and in the LRL, to minimize and quantify organic contamination. Post-Apollo curatorial operations and cleaning minimize contamination from particulates, oxygen, and water but no longer specifically address organic contamination. The organic compounds measured in Apollo samples are generally consistent with known sources of contamination.

Ochratoxin A Detection on Antibody- Immobilized on BSA-Functionalized Gold Electrodes.

PubMed

Badea, Mihaela; Floroian, Laura; Restani, Patrizia; Cobzac, Simona Codruta Aurora; Moga, Marius

2016-01-01

Ochratoxin A (OTA)-a toxin produced by Aspergillus carbonarius, Aspergillus ochraceus, and Penicillium verrucosum-is one of the most-abundant food-contaminating mycotoxins. To avoid the risk of OTA consumption for humans and animals, the rapid detection and quantitation of OTA level in different commodities are of great importance. In this work, an impedimetric immunosensor for ochratoxin A (OTA) detection, a common toxic botanical contaminant, was developed via the immobilization of anti-OTA antibody on bovine serum albumin modified gold electrodes. A four-step reaction protocol was tested to modify the gold electrode and obtain the sensing substrate. All the steps of the immunosensor elaboration and also the immunochemical reaction between surface-bound antibody and ochratoxin A were analyzed using cyclic voltammetry and electrochemical impedance spectroscopy. Modification of the impedance due to the specific antigen-antibody reaction at immunosensor surface, was used in order to detect ochratoxin A. Linear proportionality of the charge transfer resistance to the concentration of OTA allows ochratoxin A detection in the range of 2.5-100 ng/mL.

Sub-ppb Oxygen Contaminant Detection in Semi-Conductor Processing

NASA Technical Reports Server (NTRS)

Man, K. F.

1995-01-01

Gaseous contaminants such as oxygen, water vapor, nitrogen and hydrocarbons are often present in the processing environment in semiconductor device fabrication and in containerless materials processing. The contaminants arise as a result of outgassing from hot surfaces or they may be part of the impurities in commercial ultra-high purity gases. Among these gaseous contaminants, oxygen is the most reactive and, therefore, has the most adverse effects on the end product. There has been an intense effort at the Jet Propulsion Laboratory to develop different types of oxygen sorbents to reduce oxygen concentration in a microgravity processing environment to sub-ppb (parts-per-billion) levels. Higher concentrations can lead to rapid surface oxide formation, hence reducing the quality of semiconductor devices. If the concentration of oxygen in a processing chamber at 1000oC is in the ppb level, it will only take approximately 10 seconds for an oxide layer to form on the surface of a sample. The interaction of oxygen with the water surface can lead to the formation of localized defects in semi-conductor devices, hence decreasing the manufacturing yield. For example, efficient production of 64 Mb RAM chips requires contaminations below ppb levels. This paper describes a technique for measuring trace quantities of oxygen contaminants by recording the monoatomic negative ions, O-, using mass spectrometry. The O- formation from the e--O2 interaction utilizes the electron dissociative attachment method that is greatly enhanced at the resonant energy (6.8 eV). The device combines a small gridded electron ionizer with a compact mass spectrometer. The concentrations of oxygen have been measured using the method of standard additions by diluting O2 in N2. The lowest detection limit obtained was 1.2 kHz (O- count rate) at a concentration of 10-10, corresponding to 0.1 ppb.

Robust technique using an imaging plate to detect environmental radioactivity.

PubMed

Isobe, Tomonori; Mori, Yutaro; Takada, Kenta; Sato, Eisuke; Sakurai, Hideyuki; Sakae, Takeji

2013-04-01

The Fukushima Daiichi Nuclear Power Plant was severely damaged by the Great East Japan Earthquake on 11 March 2011. Consequently, a large amount of radioactive material was accidentally released. Recently, the focus has been on quantification of environmental radioactive material. However, conventional techniques require complicated and expensive measurement equipment. In this research, the authors developed a simple method to detect environmental radioactive material with an imaging plate (IP). Two specific measurement subjects were targeted: measurements for the depth distribution of radioactive material in soil and surface contamination of a building roof. For the measurement of depth distribution of radioactive material in soil, the authors ascertained that the concentration of environmental radioactivity was highest at 5 cm below the surface, and it decreased with depth. For the measurement of surface contamination of the building roof, the authors created a contamination map of the building roof. The detector developed could contact the ground directly, and unlike other survey meters, it was not influenced by peripheral radioactivity. In this study, the authors verified the feasibility of measurement of environmental radioactivity with an IP. Although the measured values of the IP were relative, further work is planned to perform evaluations of absolute quantities of radioactive material.

Detection of heavy metal ions in contaminated water by surface plasmon resonance based optical fibre sensor using conducting polymer and chitosan.

PubMed

Verma, Roli; Gupta, Banshi D

2015-01-01

Optical fibre surface plasmon resonance (SPR) based sensor for the detection of heavy metal ions in the drinking water is designed. Silver (Ag) metal and indium tin oxide (ITO) are used for the fabrication of the SPR probe which is further modified with the coating of pyrrole and chitosan composite. The sensor works on the wavelength interrogation technique and is capable of detecting trace amounts of Cd(2+), Pb(2+), and Hg(2+) heavy metal ions in contaminated water. Four types of sensing probes are fabricated and characterised for heavy metal ions out of these pyrrole/chitosan/ITO/Ag coated probe is found to be highly sensitive among all other probes. Further, the cadmium ions bind strongly to the sensing surface than other ions and due to this the sensor is highly sensitive for Cd(2+) ions. The sensor's performance is best for the low concentrations of heavy metal ions and its sensitivity decreases with the increasing concentration of heavy metal ions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vulnerability of drinking-water wells in La Crosse, Wisconsin, to enteric-virus contamination from surface water contributions.

PubMed

Borchardt, Mark A; Haas, Nathaniel L; Hunt, Randall J

2004-10-01

Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. (18)O/(16)O and (2)H/(1)H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.

Vulnerability of Drinking-Water Wells in La Crosse, Wisconsin, to Enteric-Virus Contamination from Surface Water Contributions

PubMed Central

Borchardt, Mark A.; Haas, Nathaniel L.; Hunt, Randall J.

2004-01-01

Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination. PMID:15466536

Vulnerability of drinking-water wells in La Crosse, Wisconsin, to enteric-virus contamination from surface water contributions

USGS Publications Warehouse

Borchardt, M. A.; Haas, N.L.; Hunt, R.J.

2004-01-01

Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/ 16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.

Surface contamination of hazardous drug pharmacy storage bins and pharmacy distributor shipping containers.

PubMed

Redic, Kimberly A; Fang, Kayleen; Christen, Catherine; Chaffee, Bruce W

2018-03-01

Purpose This study was conducted to determine whether there is contamination on exterior drug packaging using shipping totes from the distributor and carousel storage bins as surrogate markers of external packaging contamination. Methods A two-part study was conducted to measure the presence of 5-fluorouracil, ifosfamide, cyclophosphamide, docetaxel and paclitaxel using surrogate markers for external drug packaging. In Part I, 10 drug distributor shipping totes designated for transport of hazardous drugs provided a snapshot view of contamination from regular use and transit in and out of the pharmacy. An additional two totes designated for transport of non-hazardous drugs served as controls. In Part II, old carousel storage bins (i.e. those in use pre-study) were wiped for snapshot view of hazardous drug contamination on storage bins. New carousel storage bins were then put into use for storage of the five tested drugs and used for routine storage and inventory maintenance activities. Carousel bins were wiped at time intervals 0, 8, 16 and 52 weeks to measure surface contamination. Results Two of the 10 hazardous shipping totes were contaminated. Three of the five-old carousel bins were contaminated with cyclophosphamide. One of the old carousel bins was also contaminated with ifosfamide. There were no detectable levels of hazardous drugs on any of the new storage bins at time 0, 8 or 16 weeks. However, at the Week 52, there was a detectable level of 5-FU present in the 5-FU carousel bin. Conclusions Contamination of the surrogate markers suggests that external packaging for hazardous drugs is contaminated, either during the manufacturing process or during routine chain of custody activities. These results demonstrate that occupational exposure may occur due to contamination from shipping totes and storage bins, and that handling practices including use of personal protective equipment is warranted.

Analysis of Nonvolatile Residue (NVR) from Spacecraft Systems

NASA Technical Reports Server (NTRS)

Colony, J. A.

1985-01-01

Organic contamination on critical spacecraft surfaces can cause electronic problems, serious attenuation of various optical signals, thermal control changes, and adhesion problems. Such contaminants can be detected early by the controlled use of witness mirrors, witness plates, wipe sampling, or direct solvent extraction. Each method requires careful control of variables of technique and materials to attain the ultimate sensitivities inherent to that procedure. Subsequent chemical analysis of the contaminant sample by infrared and mass spectrometry identifies the components, gives semiquantitative estimates of contaminant thickness, indicates possible sources of the nonvolatile residue (NVR), and provides guidance for effective cleanup procedures.

Detection of organic residues on poultry processing equipment surfaces by LED-induced fluorescence imaging

USDA-ARS?s Scientific Manuscript database

Organic residues on equipment surfaces in poultry processing plants can generate cross- contamination and increase the risk of unsafe food for consumers. This research was aimed to investigate the potential of LED-induced fluorescence imaging technique for rapid inspection of stainless steel proces...

Differences in staining intensities affect reported occurrences and concentrations of Giardia spp. in surface drinking water sources

EPA Science Inventory

Aim USEPA Method 1623, or its equivalent, is currently used to monitor for protozoan contamination of surface drinking water sources worldwide. At least three approved staining kits used for detecting Cryptosporidium and Giardia are commercially available. This study focuses on ...

Multispectral fluorescence imaging for detection of bovine feces on Romaine lettuce and baby spinach leaves

USDA-ARS?s Scientific Manuscript database

Hyperspectral fluorescence imaging with ultraviolet-A excitation was used to evaluate the feasibility of two-waveband fluorescence algorithms for the detection of bovine fecal contaminants on the abaxial and adaxial surfaces of Romaine lettuce and baby spinach leaves. Correlation analysis was used t...

Location and detection of explosive-contaminated human fingerprints on distant targets using standoff laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Lucena, P.; Gaona, I.; Moros, J.; Laserna, J. J.

2013-07-01

Detection of explosive-contaminated human fingerprints constitutes an analytical challenge of high significance in security issues and in forensic sciences. The use of a laser-induced breakdown spectroscopy (LIBS) sensor working at 31 m distance to the target, fitted with 2D scanning capabilities and designed for capturing spectral information from laser-induced plasmas of fingerprints is presented. Distribution chemical maps based on Na and CN emissions are used to locate and detect chloratite, DNT, TNT, RDX and PETN residues that have been deposited on the surface of aluminum and glass substrates. An effectiveness of 100% on fingerprints detection, regardless the substrate scanned, is reached. Environmental factors that affect the prevalence of the fingerprint LIBS response are discussed.

High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia.

PubMed

Steyer, Andrej; Torkar, Karmen Godič; Gutiérrez-Aguirre, Ion; Poljšak-Prijatelj, Mateja

2011-09-01

Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks. Copyright © 2011 Elsevier GmbH. All rights reserved.

Bomb swab: Can trace explosive particle sampling and detection be improved?

PubMed

Fisher, Danny; Zach, Raya; Matana, Yossef; Elia, Paz; Shustack, Shiran; Sharon, Yarden; Zeiri, Yehuda

2017-11-01

The marked increase in international terror in recent years requires the development of highly efficient methods to detect trace amounts of explosives at airports, border crossings and check points. The preferred analytical method worldwide is the ion mobility spectrometry (IMS) that is capable of detecting most explosives at the nano-gram level. Sample collection for the IMS analysis is based on swabbing of a passenger's belongings to collect possible explosive residues. The present study examines a wide range of issues related to swab-based particle collection and analysis, in the hope of gaining deeper understanding into this technique that will serve to improve the detection process. The adhesion of explosive particles to three typical materials, plastic, metal and glass, were measured using atomic force microscopy (AFM). We found that a strong contribution of capillary forces to adhesion on glass and metal surfaces renders these substrates more promising materials upon which to find and collect explosive residues. The adhesion of explosives to different swipe materials was also examined. Here we found that Muslin, Nomex ® and polyamide membrane surfaces are the most promising materials for use as swipes. Subsequently, the efficiency of multiple swipe use - for collecting explosive residues from a glass surface using Muslin, Nomex ® and Teflon™ swipes - was examined. The study suggests that swipes used in about 5-10 "sampling and analysis cycles" have higher efficiency as compared to new unused swipes. The reason for this behavior was found to be related to the increased roughness of the swipe surface following a few swab measurements. Lastly, GC-MS analysis was employed to examine the nature of contaminants collected by the three types of swipe. The relative amounts of different contaminants are reported. The existence and interference of these contaminants have to be considered in relation to the detection efficiency of the various explosives by the IMS. Copyright © 2017 Elsevier B.V. All rights reserved.

Contamination profile of Listeria spp. in three types of ready-to-eat chicken meat products.

PubMed

Lekroengsin, Sumalin; Keeratipibul, Suwimon; Trakoonlerswilai, Kasame

2007-01-01

This study investigated contamination sources of Listeria spp. in frozen, ready-to-eat, roasted, steamed, and fried chicken meat products from a plant in Thailand, as well as the correlation between Listeria contamination in the production environment and the finished product. The cooking processes used in this factory (with a product core temperature of 80 degrees C for 1 min) were confirmed as adequate for eliminating Listeria spp. However, Listeria spp. were detected at the packing stage of roasted and steamed chicken products. An environmental swab test was conducted by means of the zone concept, whereby surfaces in the production area were divided into three zones. Zone 1 was made up of the equipment surfaces that came into direct contact with the products. Zone 2 consisted of equipment surfaces that were not in direct contact with the products, including surfaces that were difficult to be cleaned. Zone 3 included surfaces that did not come in direct contact with the products and were located far from the products. The results showed that the prevalence of Listeria spp. in roasted and steamed products was affected by the prevalence of Listeria contamination in all zones, especially zone 1, which demonstrated the highest correlation. In addition, the prevalence of Listeria contamination in zones 2 and 3 affected the prevalence of Listeria in zone 1. A correlation between Listeria on roasted chicken products and the surfaces of zone 1 at the start of production was also established.

Expanded Target-Chemical Analysis Reveals Extensive Mixed-Organic-Contaminant Exposure in U.S. Streams.

PubMed

Bradley, Paul M; Journey, Celeste A; Romanok, Kristin M; Barber, Larry B; Buxton, Herbert T; Foreman, William T; Furlong, Edward T; Glassmeyer, Susan T; Hladik, Michelle L; Iwanowicz, Luke R; Jones, Daniel K; Kolpin, Dana W; Kuivila, Kathryn M; Loftin, Keith A; Mills, Marc A; Meyer, Michael T; Orlando, James L; Reilly, Timothy J; Smalling, Kelly L; Villeneuve, Daniel L

2017-05-02

Surface water from 38 streams nationwide was assessed using 14 target-organic methods (719 compounds). Designed-bioactive anthropogenic contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics detected at least once. The 10 most-frequently detected anthropogenic-organics included eight pesticides (desulfinylfipronil, AMPA, chlorpyrifos, dieldrin, metolachlor, atrazine, CIAT, glyphosate) and two pharmaceuticals (caffeine, metformin) with detection frequencies ranging 66-84% of all sites. Detected contaminant concentrations varied from less than 1 ng L -1 to greater than 10 μg L -1 , with 77 and 278 having median detected concentrations greater than 100 ng L -1 and 10 ng L -1 , respectively. Cumulative detections and concentrations ranged 4-161 compounds (median 70) and 8.5-102 847 ng L -1 , respectively, and correlated significantly with wastewater discharge, watershed development, and toxic release inventory metrics. Log 10 concentrations of widely monitored HHCB, triclosan, and carbamazepine explained 71-82% of the variability in the total number of compounds detected (linear regression; p-values: < 0.001-0.012), providing a statistical inference tool for unmonitored contaminants. Due to multiple modes of action, high bioactivity, biorecalcitrance, and direct environment application (pesticides), designed-bioactive organics (median 41 per site at μg L -1 cumulative concentrations) in developed watersheds present aquatic health concerns, given their acknowledged potential for sublethal effects to sensitive species and lifecycle stages at low ng L -1 .

Expanded target-chemical analysis reveals extensive mixed-organic-contaminant exposure in USA streams

USGS Publications Warehouse

Bradley, Paul M.; Journey, Celeste A.; Romanok, Kristin; Barber, Larry B.; Buxton, Herbert T.; Foreman, William T.; Furlong, Edward T.; Glassmeyer, Susan T.; Hladik, Michelle L.; Iwanowicz, Luke R.; Jones, Daniel K.; Kolpin, Dana W.; Kuivila, Kathryn M.; Loftin, Keith A.; Mills, Marc A.; Meyer, Michael T.; Orlando, James L.; Reilly, Timothy J.; Smalling, Kelly L.; Villeneuve, Daniel L.

2017-01-01

Surface water from 38 streams nationwide was assessed using 14 target-organic methods (719 compounds). Designed-bioactive anthropogenic contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics detected at least once. The 10 most-frequently detected anthropogenic-organics included eight pesticides (desulfinylfipronil, AMPA, chlorpyrifos, dieldrin, metolachlor, atrazine, CIAT, glyphosate) and two pharmaceuticals (caffeine, metformin) with detection frequencies ranging 66–84% of all sites. Detected contaminant concentrations varied from less than 1 ng L–1 to greater than 10 μg L–1, with 77 and 278 having median detected concentrations greater than 100 ng L–1 and 10 ng L–1, respectively. Cumulative detections and concentrations ranged 4–161 compounds (median 70) and 8.5–102 847 ng L–1, respectively, and correlated significantly with wastewater discharge, watershed development, and toxic release inventory metrics. Log10 concentrations of widely monitored HHCB, triclosan, and carbamazepine explained 71–82% of the variability in the total number of compounds detected (linear regression; p-values: < 0.001–0.012), providing a statistical inference tool for unmonitored contaminants. Due to multiple modes of action, high bioactivity, biorecalcitrance, and direct environment application (pesticides), designed-bioactive organics (median 41 per site at μg L–1 cumulative concentrations) in developed watersheds present aquatic health concerns, given their acknowledged potential for sublethal effects to sensitive species and lifecycle stages at low ng L–1.

The biofilm-positive Staphylococcus epidermidis isolates in raw materials, foodstuffs and on contact surfaces in processing plants.

PubMed

Schlegelová, J; Babák, V; Holasová, M; Dendis, M

2008-01-01

Isolates from the "farm to fork" samples (182 isolates from 2779 samples) were examined genotypically (icaAB genes) and phenotypically (in vitro biofilm formation, typical growth on Congo red agar; CRA) with the aim to assess the risk of penetration of virulent strains of Staphylococcus epidermidis into the food chain. The contamination of meat and milk products was significantly higher in comparison with raw materials. Contamination of contact surfaces in the meat-processing plants was significantly lower than that of contact surfaces in the dairy plants. The ica genes (which precondition the biofilm formation) were concurrently detected in 20 isolates that also showed a typical growth on CRA. Two ica operon-negative isolates produced biofilm in vitro but perhaps by an ica-independent mechanism. The surfaces in the dairy plants and the milk products were more frequently contaminated with ica operon-positive strains (2.3 and 1.2 % samples) than the other sample types (0-0.6 % samples).

Challenge of false alarms in nitroaromatic explosive detection--a detection device based on surface-enhanced Raman spectroscopy.

PubMed

Wackerbarth, Hainer; Gundrum, Lars; Salb, Christian; Christou, Konstantin; Viöl, Wolfgang

2010-08-10

A challenge in the detection of explosives is the differentiation between explosives and contaminants. Synthetic musk-containing perfumes can cause false alarms, as these perfumes are nitroaromatic compounds, which can be mistaken for trinitro toluene (TNT) by some detectors. We present a detection principle based on surface-enhanced Raman scattering (SERS). A stream of the airborne compounds is focused and resublimated on a cooled nanostructured gold surface. We recorded high-resolution SERS spectra of TNT, musk xylene, and musk ketone. The nitroaromatic compounds can be identified unambiguously by their SERS spectra. Even the dominant bands containing nitro-group scissoring and symmetric stretching modes are significantly shifted by the difference in molecular structure.

Characterisation of CFRP surface contamination by laser induced fluorescence

NASA Astrophysics Data System (ADS)

Malinowski, Pawel H.; Sawczak, Miroslaw; Wandowski, Tomasz; Ostachowicz, Wieslaw M.; Cenian, Adam

2014-03-01

The application of Carbon Fibre Reinforced Polymers (CFRP) in aeronautics has been increasing. The CFRP elements are joint using rivets and adhesive bonding. The reliability of the bonding limits the use of adhesive bonding for primary aircraft structures, therefore it is important to assess the bond quality. The performance of adhesive bonds depends on the physico-chemical properties of the adhered surfaces. This research is focused on characterization of surfaces before bonding. In-situ examination of large surface materials, determine the group of methods that are preferred. The analytical methods should be non-destructive, enabling large surface analysis in relatively short time. In this work a spectroscopic method was tested that can be potentially applied for surface analysis. Four cases of surface condition were investigated that can be encountered either in the manufacturing process or during aircraft service. The first case is related to contamination of CFRP surface with hydraulic fluid. This fluid reacts with water forming a phosphoric acid that can etch the CFRP. Second considered case was related to silicone-based release agent contamination. These agents are used during the moulding process of composite panels. Third case involved moisture content in CFRP. Moisture content lowers the adhesion quality and leads to reduced performance of CFRP resulting in reduced performance of the adhesive bond. The last case concentrated on heat damage of CFRP. It was shown that laser induced fluorescence method can be useful for non-destructive evaluation of CFRP surface and some of the investigated contaminants can be easily detected.

Chemicals of emerging concern in the Great Lakes Basin: an analysis of environmental exposures.

PubMed

Klecka, Gary; Persoon, Carolyn; Currie, Rebecca

2010-01-01

This review and statistical analysis was conducted to better understand the nature and significance of environmental exposures in the Great Lakes Basin and watershed to a variety of environmental contaminants. These contaminants of interest included current-use pesticides, pharmaceuticals, organic wastewater contaminants, alkylphenol ethoxylates, perfluorinated surfactants, flame retardants, and chlorinated paraffins. The available literature was critically reviewed and used to develop a database containing 19,611 residue values for 326 substances. In many papers, sampling locations were characterized as being downstream from municipal wastewater discharges, receiving waters for industrial facilities, areas susceptible to agricultural or urban contamination, or harbors and ports. To develop an initial assessment of their potential ecological significance, the contamination levels found were compared with currently available regulatory standards, guidelines, or criteria. This review was prepared for the IJC multi-board work group, and served as background material for an expert consultation, held in March, 2009, in which the significance of the contaminants found was discussed. Moreover, the consultation attempted to identify and assess opportunities for strengthening future actions that will protect the Great Lakes. Based on the findings and conclusions of the expert consultation, it is apparent that a wide variety of chemicals of emerging concern have been detected in environmental media (air, water, sediment, biota) from the Great Lakes Basin, although many are present at only trace levels. Although the presence of these contaminants raises concerns in the public and among the scientific community, the findings must be placed in context. Significant scientific interpretation is required to understand the extent to which these chemicals may pose a threat to the ecosystem and to human health. The ability to detect chemicals in environmental media greatly surpasses our ability to understand the implications of such findings. As advances in analytical technologies occur, it is probable that substances previously found to be non-detectable will be detected. However, their presence in environmental media should not be construed to mean that they are necessarily toxic or hazardous. Current-use pesticides are tightly regulated and extensive efforts have been made to analyze for their presence in surface waters from the Great Lakes Basin. The concentrations found in surface waters for many of the pesticides are below current regulatory criteria. However, the concentrations of certain pesticides exceeded current criteria in 6-32% of the samples analyzed. Detectable concentrations of pharmaceutical compounds were present in 34% of the surface water samples. Various prescription and non-prescription drugs were detected, most frequently at locations that were proximate to the point of discharge from wastewater treatment plants or agricultural operations. At present, there are no standards, guidelines, or criteria with which to compare these contaminant concentrations. Concentrations of alkylphenol ethoxylates and their metabolites have been well studied. All surface water nonylphenol concentrations were below US ambient water quality criteria. However, the concentrations reported for some locations exceeded Canadian guidelines for water or sediment. Only limited data were available for a wide variety of organic wastewater contaminants. Measured concentrations in Great Lakes waters were generally low. Where criteria exist for comparison, the concentrations found were generally below the associated regulatory standards. However, exceedences were noted for some classes of compounds, including phthalates and polycyclic aromatic hydrocarbons. The highest environmental concentrations were reported in biota for a number of persistent, bioaccumulative, and toxic compounds (e.g., polybrominated diphenyl ethers, perfluorinated surfactants). Various stewardship as well as government risk assessment and risk management programs have been implemented over the past years for many of these compounds. Because risk management strategies for some of these contaminants have been implemented only recently, their impact on environmental concentrations, to date, remains unclear. Current evidence suggests that the concentrations of some brominated flame retardants are trending downward, while the concentrations of others appear to be increasing. Regulatory criteria are not available for many of the chemicals of emerging concern that were detected in the Great Lakes Basin. When criteria do exist, it is important to recognize that they were developed based on the best available science at the time. As the science evolves, regulatory criteria must be reassessed in light of new findings (e.g., consideration of new endpoints and mechanisms of action). Further, there are significant scientific gaps in our ability to interpret environmental monitoring data, including the need for: (a) improving the understanding of the effects of mixtures, (b) information on use of, and the commercial life cycle of chemicals and products that contain them, (c) information on source contributions and exposure pathways, and (d) the need for thoughtful additional regulatory,environmental, and health criteria. Discharges from wastewater treatment plants were identified as an important source of contaminants to surface waters in the Great Lakes Basin. Combined sewer overflows and agricultural operations were also found to be important contributors to concentrations in surface waters. Concentrations of many of the chemicals were generally the highest in the vicinity of these sources, decline with increasing distance from sources, and were generally low or non-detectable in the open waters of the Great Lakes.

Contamination of surface, ground, and drinking water from pharmaceutical production.

PubMed

Fick, Jerker; Söderström, Hanna; Lindberg, Richard H; Phan, Chau; Tysklind, Mats; Larsson, D G Joakim

2009-12-01

Low levels of pharmaceuticals are detected in surface, ground, and drinking water worldwide. Usage and incorrect disposal have been considered the major environmental sources of these microcontaminants. Recent publications, however, suggest that wastewater from drug production can potentially be a source of much higher concentrations in certain locations. The present study investigated the environmental fate of active pharmaceutical ingredients in a major production area for the global bulk drug market. Water samples were taken from a common effluent treatment plant near Hyderabad, India, which receives process water from approximately 90 bulk drug manufacturers. Surface water was analyzed from the recipient stream and from two lakes that are not contaminated by the treatment plant. Water samples were also taken from wells in six nearby villages. The samples were analyzed for the presence of 12 pharmaceuticals with liquid chromatography-mass spectrometry. All wells were determined to be contaminated with drugs. Ciprofloxacin, enoxacin, cetirizine, terbinafine, and citalopram were detected at more than 1 microg/L in several wells. Very high concentrations of ciprofloxacin (14 mg/L) and cetirizine (2.1 mg/L) were found in the effluent of the treatment plant, together with high concentrations of seven additional pharmaceuticals. Very high concentrations of ciprofloxacin (up to 6.5 mg/L), cetirizine (up to 1.2 mg/L), norfloxacin (up to 0.52 mg/L), and enoxacin (up to 0.16 mg/L) were also detected in the two lakes, which clearly shows that the investigated area has additional environmental sources of insufficiently treated industrial waste. Thus, insufficient wastewater management in one of the world's largest centers for bulk drug production leads to unprecedented drug contamination of surface, ground, and drinking water. This raises serious concerns regarding the development of antibiotic resistance, and it creates a major challenge for producers and regulatory agencies to improve the situation.

SEMICONDUCTOR TECHNOLOGY A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

NASA Astrophysics Data System (ADS)

Baohong, Gao; Yuling, Liu; Chenwei, Wang; Yadong, Zhu; Shengli, Wang; Qiang, Zhou; Baimei, Tan

2010-10-01

This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection.

Temporal changes in VOC discharge to surface water from a fractured rock aquifer during well installation and operation, Greenville, South Carolina

USGS Publications Warehouse

Vroblesky, D.A.; Robertson, J.F.

1996-01-01

Analysis of the vapor in passive vapor samplers retrieved from a streambed in fractured rock terrain implied that volatile organic carbon (VOC) discharge from ground water to surface water substantially increased following installation of a contaminant recovery well using air rotary drilling. The air rotary technique forced air into the aquifer near the stream. The injection produced an upward hydraulic gradient that appears to have transported water and contaminants from deeper parts of the aquifer through fractures into shallow parts of the aquifer. Once in the shallow flow regime, the contamination was transported to the stream, where it discharged during the next several weeks following well installation. After the recovery well was activated and began continuously pumping contaminated ground water to a treatment facility, the VOC concentrations in the stream bottom passive vapor samplers decreased to below detectable concentrations, suggesting that the withdrawal had captured the contaminated ground water that previously had discharged to the stream.

Killing of Campylobacter on contaminated plastic and wooden cutting boards by glycerol monocaprate (monocaprin).

PubMed

Thormar, H; Hilmarsson, H

2010-09-01

Contamination in the kitchen with foodborne bacteria is a risk factor in human exposure to these pathogens, an important route being transfer of bacteria from contaminated cutting boards and other surfaces to humans. The aim of this study was to test microbicidal emulsions of glycerol monocaprate (monocaprin) against Campylobacter on contaminated cutting boards. Plastic and wooden cutting boards, soiled with meat juice heavily contaminated with Campylobacter, were treated for 2 min with emulsions of monocaprin (MC) made in water or in buffer at low pH. Viable Campylobacter counts were reduced below the detectable level on plastic board surfaces after treatment with MC emulsions with or without 1.25% washing-up liquids (WUL). The counts were also greatly reduced on wooden boards (P < 0.05). Monocaprin emulsions and mixtures of MC emulsions and WUL may be useful as sanitizers/disinfectants in kitchens and in other food preparing and processing facilities. Cleaning with MC emulsions with or without WUL may reduce the risk of human exposure to Campylobacter.

Accumulation patterns of lipophilic organic contaminants in surface sediments and in economic important mussel and fish species from Jakarta Bay, Indonesia.

PubMed

Dwiyitno; Dsikowitzky, Larissa; Nordhaus, Inga; Andarwulan, Nuri; Irianto, Hari Eko; Lioe, Hanifah Nuryani; Ariyani, Farida; Kleinertz, Sonja; Schwarzbauer, Jan

2016-09-30

Non-target screening analyses were conducted in order to identify a wide range of organic contaminants in sediment and animal tissue samples from Jakarta Bay. High concentrations of di-iso-propylnaphthalenes (DIPNs), linear alkylbenzenes (LABs) and polycyclic aromatic hydrocarbons (PAHs) were detected in all samples, whereas phenylmethoxynaphthalene (PMN), DDT and DDT metabolites (DDX) were detected at lower concentrations. In order to evaluate the uptake and accumulation by economic important mussel (Perna viridis) and fish species, contaminant patterns of DIPNs, LABs and PAHs in different compartments were compared. Different patterns of these contaminant groups were found in sediment and animal tissue samples, suggesting compound-specific accumulation and metabolism processes. Significantly higher concentrations of these three contaminant groups in mussel tissue as compared to fish tissue from Jakarta Bay were found. Because P. viridis is an important aquaculture species in Asia, this result is relevant for food safety. Copyright © 2016 Elsevier Ltd. All rights reserved.

A General LC-MS/MS Method for Monitoring Potential β-Lactam Contamination in Drugs and Drug-Manufacturing Surfaces.

PubMed

Qiu, Chen; Zhu, Hongbin; Ruzicka, Connie; Keire, David; Ye, Hongping

2018-05-15

Penicillins and some non-penicillin β-lactams may cause potentially life-threatening allergic reactions. Thus, possible cross contamination of β-lactams in food or drugs can put people at risk. Therefore, when there is a reasonable possibility that a non-penicillin product could be contaminated by penicillin, the drug products are tested for penicillin contamination. Here, a sensitive and rapid method for simultaneous determination of multiple β-lactam antibiotics using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. Mass spectral acquisition was performed on a Q-Exactive HF mass spectrometer in positive ion mode with parallel reaction monitoring (PRM). The method was validated for seven β-lactam antibiotics including one or two from each class and a synthetic intermediate. The quantification precision and accuracy at 200 ppb were in the range of ± 1.84 to ± 4.56 and - 5.20 to 3.44%, respectively. The limit of detection (LOD) was 0.2 ppb, and the limit of quantitation (LOQ) was 2 ppb with a linear dynamic range (LDR) of 2-2000 ppb for all eight β-lactams. From various drug products, the recoveries of eight β-lactams at 200 and 2 ppb ranged from 93.8 ± 3.2 to 112.1 ± 4.2% and 89.7 ± 4.6 to 110.6 ± 1.9%, respectively. The application of the method for detecting cross contamination of trace β-lactams (0.2 ppb) and for monitoring facility surface cleaning was also investigated. This sensitive and fast method was fit-for-purpose for detecting and quantifying trace amount of β-lactam contamination, monitoring cross contamination in manufacturing processes, and determining potency for regulatory purposes and for quality control.

Prevalence of Campylobacter, Salmonella, and Escherichia coli on the external packaging of raw meat.

PubMed

Burgess, F; Little, C L; Allen, G; Williamson, K; Mitchelli, R T

2005-03-01

During September and October 2002, 3,662 prepackaged raw meat samples were collected to evaluate the extent and nature of microbiological contamination on external surfaces of the packaging, which could potentially cross-contaminate ready-to-eat foods during and after purchase. Salmonella was detected on two (<1%) samples of external packaging (both from raw chicken), and Campylobacter was detected on 41 (1.1%) samples of external packaging. The external packaging of game fowl exhibited the highest Campylobacter contamination (3.6%), followed by raw chicken (3.0%), lamb (1.6%), turkey (0.8%), pork (0.2%), and beef (0.1%); Campylobacter jejuni and Campylobacter coli accounted for 59% (24 of 41) and 24% (10 of 41) of the contaminating Campylobacter species, respectively. C. coli isolates from the external packaging were more multiresistant to antimicrobial drugs, including quinolones such as ciprofloxacin, than was C. jejuni. Escherichia coli (an indicator of fecal contamination) was isolated from the external packaging on 4% of the raw meat samples at levels of 40 to 10(5) CFU per swab. The external packaging of raw meats is a vehicle for potential cross-contamination by Campylobacter, Salmonella, and E. coli in retail premises and consumers' homes. The external surface of heat-sealed packaging was less frequently contaminated with Campylobacter and E. coli compared with other types of packaging (e.g., overwrapping, bag, and tie tape) (P < 0.0001 to 0.01). In addition, external packaging of raw meats was contaminated less frequently with Campylobacter and E. coli when packaging was intact, packaging and display areas were visually clean, display temperatures were below 8 degrees C, and hazard analysis systems were in place.

Aerobic biodegradation potential of endocrine disrupting chemicals in surface-water sediment at Rocky Mountains National Park, USA

USGS Publications Warehouse

Bradley, Paul M.; Battaglin, William A.; Iwanowicz, Luke R.; Clark, Jimmy M.; Journey, Celeste A.

2016-01-01

Endocrine disrupting chemicals (EDC) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDC, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountains National Park (ROMO). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 14C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. ROMO bed sediment microbial communities also effectively degraded the xenoestrogens, bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The current results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged.

Forced-air warming blowers: An evaluation of filtration adequacy and airborne contamination emissions in the operating room.

PubMed

Albrecht, Mark; Gauthier, Robert L; Belani, Kumar; Litchy, Mark; Leaper, David

2011-05-01

Forced-air warming (FAW) is widely used to prevent hypothermia during surgical procedures. The airflow from these blowers is often vented near the operative site and should be free of contaminants to minimize the risk of surgical site infection. Popular FAW blowers contain a 0.2-μm rated intake filter to reduce these risks. However, there is little evidence that the efficiency of the intake filter is adequate to prevent airborne contamination emissions or protect the internal air path from microbial contamination buildup. Five new intake filters were obtained directly from the manufacturer (Bair Hugger 505, model 200708D; Arizant Healthcare, Eden Prairie, MN), and 5 model 200708C filters currently in hospital use were removed from FAW devices. The retention efficiency of these filters was assessed using a monodisperse sodium chloride aerosol. In the same hospitals, internal air path surface swabs and hose outlet particle counts were performed on 52 forced-air warming devices (all with the model 200708C filter) to assess internal microbial buildup and airborne contamination emissions. Intake filter retention efficiency at 0.2 μm was 93.8% for the 200708C filter and 61.3% at for the 200708D filter. The 200708D filter obtained directly from the manufacturer has a thinner filtration media than the 200708C filter in current hospital use, suggesting that the observed differences in retention efficiency were due to design changes. Fifty-eight percent of the FAW blowers evaluated were internally generating and emitting airborne contaminants, with microorganisms detected on the internal air path surfaces of 92.3% of these blowers. Isolates of Staphylococcus aureus, coagulase-negative Staphylococcus, and methicillin-resistant S aureus were detected in 13.5%, 3.9%, and 1.9% of FAW blowers, respectively. The design of popular FAW devices using the 200708C filter was found to be inadequate for preventing the internal buildup and emission of microbial contaminants into the operating room. Substandard intake filtration allowed airborne contaminants (both viable and nonviable) to penetrate the intake filter and reversibly attach to the internal surfaces within the FAW blowers. The reintroduction of these contaminants into the FAW blower air stream was detected and could contribute to the risk of cross-infection. Given the deficiencies identified with the 200708C intake filter, the introduction of a new filter (model 200708D) with substantially lower retention efficiency is of concern. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Health assessment for Lang Property National Priorities List (NPL) site, Pemberton Township, Burlington County, New Jersey, Region 2. CERCLIS No. NJD980505382. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-04-17

The Lang Property National Priorities List Site is located in Pemberton Township, Burlington County, New Jersey. Unauthorized disposal of hazardous wastes occurred on approximately two acres of the 40-acre site. The contaminant classes that were identified on the site are volatile organic compounds (VOCs), semi-volatile organic compounds (semi-VOCs), polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, and metals. The contaminant classes of concern are PCBs, VOCs, and semi-VOCs for on-site ground water. VOCs is the contaminant class of concern for sediments and surface water. The on-site ground water is highly contaminated; at the maximum chemical concentrations detected, use of thismore » water without treatment would pose a human health concern. The potential does exist for human exposure to ground water contaminants by ingestion, inhalation of volatilized VOCs from ground water, and dermal absorption. The surface soils are also highly contaminated and represent a current possible as well as future human health concern for trespassers, blueberry farm workers and harvesters, and construction and remedial workers.« less

Results of the basewide monitoring program at Wright-Patterson Air Force Base, Ohio, 1993-1994

USGS Publications Warehouse

Schalk, C.W.; Cunningham, W.L.

1996-01-01

Geologic and hydrologic data were collected at Wright-Patterson Air Force Base (WPAFB), Ohio, as part of Basewide Monitoring Program (BMP) that began in 1992. The BMP was designed as a long-term project to character ground-water and surface-water quality (including streambed sediments), describe water-quality changes as water enters, flows across, and exits the Base, and investigate the effects of activities at WPAFB on regional water quality. Ground water, surface ware, and streambed sediment were sampled in four rounds between August 1993 and September 1994 to provide the analytical data needed to address the objectives of the BMP. Surface-water-sampling rounds were designed to include most of the seasonal hydrologic conditions encountered in southwestern Ohio, including baseflow conditions and spring runoff. Ground-water-sampling rounds were scheduled for times of recession and recharfe. Ground-water data were used to construct water-table, potentiometric, and vertical gradient maps of the WPAFB area. Water levels have not changed significantly since 1987, but the effects of pumping on and near the Base can have a marked effect on water levels in localized areas. Ground-ware gradients generally were downward throughout Area B (the southwestern third of the Base) and in the eastern third of Areas A and C (the northeastern two-thirds of the Base), and were upward in the vicinity of Mad River. Stream-discharge measurements verified these gradients. Many of the U.S. Environmental Protection Agency maximum contaminant level (MCL) exceedances of inorganic constituents in ground water were associated with water from the bedrock. Exceedances of concentrations of chromium and nickel were found consistently in five wells completed in the glacial aquifer beneath the Base. Five organic compounds [trichloroethylene (TCE), tetrachloroethylene (PCE), vinyl chloride, benzene, and bis(2-ethylhexyl) phthalate] were detected at concentrations that exceeded MCLs; all of the TCE, PCE, and vinyl chloride exceedances were in water from glacial aquifer, whereas the benzene exceedance and most of the bis(2-ethylhexyl) phthalate exceedances were in water from the bedrock. TCE (16 exceedances) and PCE (11 exceedances) most frequently exceeded the MCLs and were detected in the most samples. A decrease in concentrations of inorganic and organic compounds with depth suggest that many constituents detected in ground-water samples are associated partly with human activities, in addition to their natural occurrence. Included in the list of these constituents are nickel, chromium, copper, lead vanadium, zinc, bromide, and nitrate. Many constituents are not found at depths greater than 60 to 80 feet, possibly indicating that human effects on ground-water quality are limited to shallow flow systems. Organic compounds detected in shallow or intermediate-depth wells were aligned mostly with flowpaths that pass through or near identified hazardous-waste sites. Few organic contaminants were detected in surface water. The only organic compound to exceed MCLs for drinking water was bis(2-ethylhexyl) phthalate, but it was detected at concentrations just above the MCL. Inorganic constituents detected at concentration exceeding MCLs include beryllium (twice), lead (once), thallium (once), and gross alpha radiation (once). No polycyclic aromatic (PAHs) were detected in surface-water samples. The highest concentrations of contaminants detected during a storm event were in samples from upgradient locations, indicating that off-Base sources may contribute to surface-water contamination. Inorganic and organic contaminants were found in streambed sediments at WPAFB, primarily in Areas A and C. Trace metals such as lead, mercury, arsenic, and cadmium were detected at 16 locations at concentrations considered 'elevated' according to a ranking scheme for sediments. PAHS were the organic compounds detected most frequently and in highest concentrations organo

Surveillance of bacterial contamination in small animal veterinary hospitals with special focus on antimicrobial resistance and virulence traits of enterococci.

PubMed

KuKanich, Kate S; Ghosh, Anuradha; Skarbek, Jennifer V; Lothamer, Kale M; Zurek, Ludek

2012-02-15

To determine the prevalence of bacterial contamination on 4 surfaces of 4 types of standard equipment in small animal veterinary hospitals. Surveillance study. 10 small animal veterinary hospitals. Each hospital was visited 3 times at 4-month intervals; at each visit, a cage door, stethoscope, rectal thermometer, and mouth gag were swabbed. Swab samples were each plated onto media for culture of enterococci and organisms in the family Enterobacteriaceae. Enterococci were identified via a species-specific PCR assay and sodA gene sequencing; species of Enterobacteriaceae were identified with a biochemical test kit. Antimicrobial susceptibility was assessed via the disk diffusion method. Enterococci were screened for virulence traits and genotyped to assess clonality. Among the 10 hospitals, enterococci were isolated from cage doors in 7, from stethoscopes in 7, from thermometers in 6, and from mouth gags in 1; contamination with species of Enterobacteriaceae was rare. Enterococci were mainly represented by Enterococcus faecium (35.4%), Enterococcus faecalis (33.2%), and Enterococcus hirae (28.3%). Antimicrobial resistance was common in E. faecium, whereas virulence traits were present in 99% of E. faecalis isolates but not in E. faecium isolates. Clonal multidrug-resistant E. faecium was isolated from several surfaces at 1 hospital over multiple visits, whereas sporadic nonclonal contamination was detected in other hospitals. Contamination of surfaces in small animal veterinary hospitals with multidrug-resistant enterococci is a potential concern for pets and humans contacting these surfaces. Implementing precautions to minimize enterococcal contamination on these surfaces is recommended.

Detection of toxic industrial chemicals in water supplies using surface-enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Spencer, Kevin M.; Sylvia, James M.; Spencer, Sarah A.; Clauson, Susan L.

2010-04-01

An effective method to create fear in the populace is to endanger the water supply. Homeland Security places significant importance on ensuring drinking water integrity. Beyond terrorism, accidental supply contamination from a spill or chemical residual increases is a concern. A prominent class of toxic industrial chemicals (TICs) is pesticides, which are prevalent in agricultural use and can be very toxic in minute concentrations. Detection of TICs or warfare agents must be aggressive; the contaminant needs to be rapidly detected and identified to enable isolation and remediation of the contaminated water while continuing a clean water supply for the population. Awaiting laboratory analysis is unacceptable as delay in identification and remediation increases the likelihood of infection. Therefore, a portable or online water quality sensor is required that can produce rapid results. In this presentation, Surface-Enhanced Raman Spectroscopy (SERS) is discussed as a viable fieldable sensor that can be immersed directly into the water supply and can provide results in <5 minutes from the time the instrument is turned on until analysis is complete. The ability of SERS to detect several chemical warfare agent degradation products, simulants and toxic industrial chemicals in distilled water, tap water and untreated water will be shown. In addition, results for chemical warfare agent degradation products and simulants will be presented. Receiver operator characteristic (ROC) curves will also be presented.

Prevalence of Rotavirus Genogroup A and Norovirus Genogroup II in Bassaseachic Falls National Park Surface Waters in Chihuahua, Mexico

PubMed Central

Delgado-Gardea, Ma. Carmen E.; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Mendieta-Mendoza, Aurora; Zavala-Díaz de la Serna, Francisco Javier; Contreras-Cordero, Juan Francisco; Erosa-de la Vega, Gilberto; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, Carmen; Infante-Ramírez, Rocío

2017-01-01

In areas lacking potable water treatment, drinking contaminated water may represent a public health threat. In addition to enteropathogenic bacteria and parasites, fecal contamination in water environments is associated with the transmission of enteric viruses and other causal agents of infectious disease. Rotavirus and norovirus are the main enteric viral agents responsible for diarrheic outbreaks. The aim of the present study was to detect seasonal variation of rotavirus and norovirus in the surface water at Bassaseachic Falls National Park during 2013. Rivers and streams within and nearby this park were sampled once in each season during 2013. Viral concentration was carried out by a handmade filtration equipment, using a commercial electropositive membrane coupled with the virus absortion elution technique (VIRADEL©). Detection of rotavirus and norovirus was performed by SYBR Green reverse transcription-real time polymerase chain reaction (SYBR GREEN© RT-qPCR) analyses. Norovirus genogroup II was detected in samples collected in June and October 2013. In the case of rotavirus, genogroup A was detected in March and June. The presence of rotavirus and norovirus was related to viral acute diarrhea in children less than five years of age, who were inhabiting the sampled areas. This may indicates that the contaminated water was potentially a risk factor for regional diarrheic outbreaks. PMID:28475152

DETECTION OF A GROUND-WATER/SURFACE-WATER INTERFACE WITH DIRECT-PUSH EQUIPMENT

EPA Science Inventory

A ground-water/surface-water interface (GSI) was documented at the Thermo Chem CERCLA Site in Muskegon, MI via direct-push (DP) sampling. At that time, contaminated ground water flowed from the upland area of the site into the Black Creek floodplain. DP rods equipped with a 1.5...

Shiga toxin-producing Escherichia coli in meat: a preliminary simulation study on detection capabilities for three sampling methods

USDA-ARS?s Scientific Manuscript database

The objective of this simulation study is to determine which sampling method (Cozzini core sampler, core drill shaving, and N-60 surface excision) will better detect Shiga Toxin-producing Escherichia coli (STEC) at varying levels of contamination when present in the meat. 1000 simulated experiments...

Evaluation of subsurface exploration, sampling, and water-quality-analysis methods at an abandoned wood-preserving plant site at Jackson, Tennessee

USGS Publications Warehouse

Parks, W.S.; Carmichael, J.K.; Mirecki, J.E.

1993-01-01

Direct Push Technology (DPT) and a modified-auger method of sampling were used at an abandoned wood-preserving plant site at Jackson, Tennessee, to collect lithologic data and ground-water samples in an area known to be affected by a subsurface creosote plume. The groundwater samples were analyzed using (1) gas chromatography with photo-ionization detection (GS/PID), (2) high- performance liquid chromatography (HPLC), (3) colonmetric phenol analysis, and (4) toxicity bioassay. DPT piezocone and cone-penetrometer-type tools provided lithologic data and ground-water samples at two onsite stations to a depth of refusal of about 35 feet below land surface. With the assistance of an auger rig, this depth was extended to about 65 feet by pushing the tools in advance of the augers. Following the DPT work, a modified-auger method was tested by the USGS. This method left doubt as to the integrity of the samples collected once zones of contamination were penetrated. GC/PID and HPLC methods of water-quality analysis provided the most data concerning contaminants in the ground-water and proved to be the most effective in creosote plume detection. Analyses from these methods showed that the highest concentrations of contaminants were detected at depths less than about 35 feet below land surface. Phenol analyses provided data supplemental to the HPLC analyses. Bioassay data indicated that toxicity associated with the plume extended to depths of about 55 feet below land surface.

Riverbank filtration potential of pharmaceuticals in a wastewater-impacted stream

USGS Publications Warehouse

Bradley, Paul M.; Barber, Larry B.; Duris, Joseph W.; Foreman, William T.; Furlong, Edward T.; Hubbard, Laura E.; Hutchinson, Kasey J.; Keefe, Steffanie H.; Kolpin, Dana W.

2014-01-01

Pharmaceutical contamination of shallow groundwater is a substantial concern in effluent-dominated streams, due to high aqueous mobility, designed bioactivity, and effluent-driven hydraulic gradients. In October and December 2012, effluent contributed approximately 99% and 71%, respectively, to downstream flow in Fourmile Creek, Iowa, USA. Strong hydrologic connectivity was observed between surface-water and shallow-groundwater. Carbamazepine, sulfamethoxazole, and immunologically-related compounds were detected in groundwater at greater than 0.02 μg L−1 at distances up to 6 m from the stream bank. Direct aqueous-injection HPLC-MS/MS revealed 43% and 55% of 110 total pharmaceutical analytes in surface-water samples in October and December, respectively, with 16% and 6%, respectively, detected in groundwater approximately 20 m from the stream bank. The results demonstrate the importance of effluent discharge as a driver of local hydrologic conditions in an effluent-impacted stream and thus as a fundamental control on surface-water to groundwater transport of effluent-derived pharmaceutical contaminants.

Automated Telerobotic Inspection Of Surfaces

NASA Technical Reports Server (NTRS)

Balaram, J.; Prasad, K. Venkatesh

1996-01-01

Method of automated telerobotic inspection of surfaces undergoing development. Apparatus implementing method includes video camera that scans over surfaces to be inspected, in manner of mine detector. Images of surfaces compared with reference images to detect flaws. Developed for inspecting external structures of Space Station Freedom for damage from micrometeorites and debris from prior artificial satellites. On Earth, applied to inspection for damage, missing parts, contamination, and/or corrosion on interior surfaces of pipes or exterior surfaces of bridges, towers, aircraft, and ships.

Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula

2010-12-16

Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the probability of correct detection (PCD) (or equivalently the false negative rate FNR = 1 - PCD). The PCD/FNR may depend on the 1) method of contaminant deposition, 2) surface concentration of the contaminant, 3) surface material being sampled, 4) sample collection method, 5)more » sample storage/transportation conditions, 6) sample processing method, and 7) sample analytical method. A review of the literature found 17 laboratory studies that focused on swab, wipe, or vacuum samples collected from a variety of surface materials contaminated by BA or a surrogate, and used culture methods to determine the surface contaminant concentration. These studies quantified performance of the sampling and analysis methods in terms of recovery efficiency (RE) and not PCD/FNR (which left a major gap in available information). Quantifying the PCD/FNR under a variety of conditions is a key aspect of validating sample and analysis methods, and also for calculating the confidence in characterization or clearance decisions based on a statistical sampling plan. A laboratory study was planned to partially fill the gap in PCD/FNR results. This report documents the experimental design developed by Pacific Northwest National Laboratory and Sandia National Laboratories (SNL) for a sponge-wipe method. The study will investigate the effects on key response variables from six surface materials contaminated with eight surface concentrations of a BA surrogate (Bacillus atrophaeus). The key response variables include measures of the contamination on test coupons of surface materials tested, contamination recovered from coupons by sponge-wipe samples, RE, and PCD/FNR. The experimental design involves 16 test runs, to be performed in two blocks of eight runs. Three surface materials (stainless steel, vinyl tile, and ceramic tile) were tested in the first block, while three other surface materials (plastic, painted wood paneling, and faux leather) will be tested in the second block. The eight surface concentrations of the surrogate were randomly assigned to test runs within each block. Some of the concentrations will be very low and may present challenges for deposition, sampling, and analysis. However, such tests are needed to investigate RE and PCD/FNR over the full range of concentrations of interest. In each run, there will be 10 test coupons of each of the three surface materials. A positive control sample will be generated prior to each test sample. The positive control results will be used to 1) calculate RE values for the wipe sampling and analysis method, and 2) fit RE- and PCD-concentration equations, for each of the six surface materials. Data analyses will support 1) estimating the PCD for each combination of contaminant concentration and surface material, 2) estimating the surface concentrations and their uncertainties of the contaminant for each combination of concentration and surface material, 3) estimating RE (%) and their uncertainties for each combination of contaminant concentration and surface material, 4) fitting PCD-concentration and RE-concentration equations for each of the six surface materials, 5) assessing goodness-of-fit of the equations, and 6) quantifying the uncertainty in PCD and RE predictions made with the fitted equations.« less

Fecal pollution source tracking toolbox for identification, evaluation and characterization of fecal contamination in receiving urban surface waters and groundwater.

PubMed

Tran, Ngoc Han; Gin, Karina Yew-Hoong; Ngo, Huu Hao

2015-12-15

The quality of surface waters/groundwater of a geographical region can be affected by anthropogenic activities, land use patterns and fecal pollution sources from humans and animals. Therefore, the development of an efficient fecal pollution source tracking toolbox for identifying the origin of the fecal pollution sources in surface waters/groundwater is especially helpful for improving management efforts and remediation actions of water resources in a more cost-effective and efficient manner. This review summarizes the updated knowledge on the use of fecal pollution source tracking markers for detecting, evaluating and characterizing fecal pollution sources in receiving surface waters and groundwater. The suitability of using chemical markers (i.e. fecal sterols, fluorescent whitening agents, pharmaceuticals and personal care products, and artificial sweeteners) and/or microbial markers (e.g. F+RNA coliphages, enteric viruses, and host-specific anaerobic bacterial 16S rDNA genetic markers) for tracking fecal pollution sources in receiving water bodies is discussed. In addition, this review also provides a comprehensive approach, which is based on the detection ratios (DR), detection frequencies (DF), and fate of potential microbial and chemical markers. DR and DF are considered as the key criteria for selecting appropriate markers for identifying and evaluating the impacts of fecal contamination in surface waters/groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

Salmon Site Remedial Investigation Report, Exhibit 5

DOE Office of Scientific and Technical Information (OSTI.GOV)

USDOE /NV

1999-09-01

This Salmon Site Remedial Investigation Report provides the results of activities initiated by the U.S. Department of Energy (DOE) to determine if contamination at the Salmon Site poses a current or future risk to human health and the environment. These results were used to develop and evaluate a range of risk-based remedial alternatives. Located in Lamar County, Mississippi, the Salmon Site was used by the U.S. Atomic Energy Commission (predecessor to the DOE) between 1964 and 1970 for two nuclear and two gas explosions conducted deep underground in a salt dome. The testing resulted in the release of radionuclides intomore » the salt dome. During reentry drilling and other site activities, liquid and solid wastes containing radioactivity were generated resulting in surface soil and groundwater contamination. Most of the waste and contaminated soil and water were disposed of in 1993 during site restoration either in the cavities left by the tests or in an injection well. Other radioactive wastes were transported to the Nevada Test Site for disposal. Nonradioactive wastes were disposed of in pits at the site and capped with clean soil and graded. The preliminary investigation showed residual contamination in the Surface Ground Zero mud pits below the water table. Remedial investigations results concluded the contaminant concentrations detected present no significant risk to existing and/or future land users, if surface institutional controls and subsurface restrictions are maintained. Recent sampling results determined no significant contamination in the surface or shallow subsurface. The test cavity resulting from the experiments is contaminated and cannot be economically remediated with existing technologies. The ecological sampling did not detect biological uptake of contaminants in the plants or animals sampled. Based on the current use of the Salmon Site, the following remedial actions were identified to protect both human health and the environment: (1) the installation of a water supply system that will provide potable water to the site and residence in the proximity to the site; (2) continued maintenance of surface institutional controls and subsurface restrictions; and (3) continue to implement the long-term hydrologic monitoring program. The Salmon Site will be relinquished the State of Mississippi as mandated by Public Law 104-201-September 23, 1996, to be used as a demonstration forest/wildlife refuge. Should the land use change in the future and/or monitoring information indicates a change in the site conditions, the DOE will reassess the risk impacts to human health and the environment.« less

Salmon Site Remedial Investigation Report, Main Body

DOE Office of Scientific and Technical Information (OSTI.GOV)

US DOE /NV

1999-09-01

This Salmon Site Remedial Investigation Report provides the results of activities initiated by the U.S. Department of Energy (DOE) to determine if contamination at the Salmon Site poses a current or future risk to human health and the environment. These results were used to develop and evaluate a range of risk-based remedial alternatives. Located in Lamar County, Mississippi, the Salmon Site was used by the U.S. Atomic Energy Commission (predecessor to the DOE) between 1964 and 1970 for two nuclear and two gas explosions conducted deep underground in a salt dome. The testing resulted in the release of radionuclides intomore » the salt dome. During reentry drilling and other site activities, liquid and solid wastes containing radioactivity were generated resulting in surface soil and groundwater contamination. Most of the waste and contaminated soil and water were disposed of in 1993 during site restoration either in the cavities left by the tests or in an injection well. Other radioactive wastes were transported to the Nevada Test Site for disposal. Nonradioactive wastes were disposed of in pits at the site and capped with clean soil and graded. The preliminary investigation showed residual contamination in the Surface Ground Zero mud pits below the water table. Remedial investigations results concluded the contaminant concentrations detected present no significant risk to existing and/or future land users, if surface institutional controls and subsurface restrictions are maintained. Recent sampling results determined no significant contamination in the surface or shallow subsurface. The test cavity resulting from the experiments is contaminated and cannot be economically remediated with existing technologies. The ecological sampling did not detect biological uptake of contaminants in the plants or animals sampled. Based on the current use of the Salmon Site, the following remedial actions were identified to protect both human health and the environment: (1) the installation of a water supply system that will provide potable water to the site and residence in the proximity to the site; (2) continued maintenance of surface institutional controls and subsurface restrictions; and (3) continue to implement the long-term hydrologic monitoring program. The Salmon Site will be relinquished the State of Mississippi as mandated by Public Law 104-201-September 23, 1996, to be used as a demonstration forest/wildlife refuge. Should the land use change in the future and/or monitoring information indicates a change in the site conditions, the DOE will reassess the risk impacts to human health and the environment.« less

Salmon Site Remedial Investigation Report, Exhibit 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

USDOE NV

1999-09-01

This Salmon Site Remedial Investigation Report provides the results of activities initiated by the U.S. Department of Energy (DOE) to determine if contamination at the Salmon Site poses a current or future risk to human health and the environment. These results were used to develop and evaluate a range of risk-based remedial alternatives. Located in Lamar County, Mississippi, the Salmon Site was used by the U.S. Atomic Energy Commission (predecessor to the DOE) between 1964 and 1970 for two nuclear and two gas explosions conducted deep underground in a salt dome. The testing resulted in the release of radionuclides intomore » the salt dome. During reentry drilling and other site activities, liquid and solid wastes containing radioactivity were generated resulting in surface soil and groundwater contamination. Most of the waste and contaminated soil and water were disposed of in 1993 during site restoration either in the cavities left by the tests or in an injection well. Other radioactive wastes were transported to the Nevada Test Site for disposal. Nonradioactive wastes were disposed of in pits at the site and capped with clean soil and graded. The preliminary investigation showed residual contamination in the Surface Ground Zero mud pits below the water table. Remedial investigations results concluded the contaminant concentrations detected present no significant risk to existing and/or future land users, if surface institutional controls and subsurface restrictions are maintained. Recent sampling results determined no significant contamination in the surface or shallow subsurface. The test cavity resulting from the experiments is contaminated and cannot be economically remediated with existing technologies. The ecological sampling did not detect biological uptake of contaminants in the plants or animals sampled. Based on the current use of the Salmon Site, the following remedial actions were identified to protect both human health and the environment: (1) the installation of a water supply system that will provide potable water to the site and residence in the proximity to the site; (2) continued maintenance of surface institutional controls and subsurface restrictions; and (3) continue to implement the long-term hydrologic monitoring program. The Salmon Site will be relinquished the State of Mississippi as mandated by Public Law 104-201-September 23, 1996, to be used as a demonstration forest/wildlife refuge. Should the land use change in the future and/or monitoring information indicates a change in the site conditions, the DOE will reassess the risk impacts to human health and the environment.« less

Detection of semi-volatile organic compounds (SVOCs) in surface water, soil, and groundwater in a chemical industrial park in Eastern China.

PubMed

Liu, Benhua; Li, Yuehua; Ma, Jianfeng; Huang, Linxian; Chen, Liang

2016-01-01

China is suffering from serious water and soil pollution, especially in the North China Plain. This work investigated semi-volatile organic compounds (SVOCs) in surface water, groundwater and soil within a chemical industrial park in Eastern China, for which the volatile organic compound (VOC) results have been previously reported. A total of 20 samples were collected from the field, and analyzed in the laboratory. A 100% detection frequency of SVOCs in samples from this chemical industrial park was observed (same as VOCs). Moreover, the detection frequency of 113 SVOCs in each sample reached 15.93, 12.39 and 20.35% for surface water, groundwater and soil, respectively. The most detected SVOCs in the park included N-containing SVOCs, polycyclic aromatic hydrocarbons, phthalates, organic pesticides and polychlorodiphenyls. The elevated detecting frequencies and concentration levels of SVOCs identified in the groundwater were attributed to the intensive chemical production activities in the park. In addition, the agricultural activities in the area might also have contributed to the SVOCs to the groundwater. The results of VOCs and SVOCs from this and previous studies suggest that the groundwater in this industrial park has been severely contaminated, and the contamination likely spreads beyond the park. Imminent hydrogeological assessments and remedial actions are warranted to eliminate the source and mitigate the potential plume expansion beyond the park boundary.

Stormwater plume detection by MODIS imagery in the southern California coastal ocean

USGS Publications Warehouse

Nezlin, N.P.; DiGiacomo, P.M.; Diehl, D.W.; Jones, B.H.; Johnson, S.C.; Mengel, M.J.; Reifel, K.M.; Warrick, J.A.; Wang, M.

2008-01-01

Stormwater plumes in the southern California coastal ocean were detected by MODIS-Aqua satellite imagery and compared to ship-based data on surface salinity and fecal indicator bacterial (FIB) counts collected during the Bight'03 Regional Water Quality Program surveys in February-March of 2004 and 2005. MODIS imagery was processed using a combined near-infrared/shortwave-infrared (NIR-SWIR) atmospheric correction method, which substantially improved normalized water-leaving radiation (nLw) optical spectra in coastal waters with high turbidity. Plumes were detected using a minimum-distance supervised classification method based on nLw spectra averaged within the training areas, defined as circular zones of 1.5-5.0-km radii around field stations with a surface salinity of S 33.0 ('ocean'). The plume optical signatures (i.e., the nLw differences between 'plume' and 'ocean') were most evident during the first 2 days after the rainstorms. To assess the accuracy of plume detection, stations were classified into 'plume' and 'ocean' using two criteria: (1) 'plume' included the stations with salinity below a certain threshold estimated from the maximum accuracy of plume detection; and (2) FIB counts in 'plume' exceeded the California State Water Board standards. The salinity threshold between 'plume' and 'ocean' was estimated as 32.2. The total accuracy of plume detection in terms of surface salinity was not high (68% on average), seemingly because of imperfect correlation between plume salinity and ocean color. The accuracy of plume detection in terms of FIB exceedances was even lower (64% on average), resulting from low correlation between ocean color and bacterial contamination. Nevertheless, satellite imagery was shown to be a useful tool for the estimation of the extent of potentially polluted plumes, which was hardly achievable by direct sampling methods (in particular, because the grids of ship-based stations covered only small parts of the plumes detected via synoptic MODIS imagery). In most southern California coastal areas, the zones of bacterial contamination were much smaller than the areas of turbid plumes; an exception was the plume of the Tijuana River, where the zone of bacterial contamination was comparable with the zone of plume detected by ocean color. ?? 2008 Elsevier Ltd.

Stormwater plume detection by MODIS imagery in the southern California coastal ocean

NASA Astrophysics Data System (ADS)

Nezlin, Nikolay P.; DiGiacomo, Paul M.; Diehl, Dario W.; Jones, Burton H.; Johnson, Scott C.; Mengel, Michael J.; Reifel, Kristen M.; Warrick, Jonathan A.; Wang, Menghua

2008-10-01

Stormwater plumes in the southern California coastal ocean were detected by MODIS-Aqua satellite imagery and compared to ship-based data on surface salinity and fecal indicator bacterial (FIB) counts collected during the Bight'03 Regional Water Quality Program surveys in February-March of 2004 and 2005. MODIS imagery was processed using a combined near-infrared/shortwave-infrared (NIR-SWIR) atmospheric correction method, which substantially improved normalized water-leaving radiation (nLw) optical spectra in coastal waters with high turbidity. Plumes were detected using a minimum-distance supervised classification method based on nLw spectra averaged within the training areas, defined as circular zones of 1.5-5.0-km radii around field stations with a surface salinity of S < 32.0 ("plume") and S > 33.0 ("ocean"). The plume optical signatures (i.e., the nLw differences between "plume" and "ocean") were most evident during the first 2 days after the rainstorms. To assess the accuracy of plume detection, stations were classified into "plume" and "ocean" using two criteria: (1) "plume" included the stations with salinity below a certain threshold estimated from the maximum accuracy of plume detection; and (2) FIB counts in "plume" exceeded the California State Water Board standards. The salinity threshold between "plume" and "ocean" was estimated as 32.2. The total accuracy of plume detection in terms of surface salinity was not high (68% on average), seemingly because of imperfect correlation between plume salinity and ocean color. The accuracy of plume detection in terms of FIB exceedances was even lower (64% on average), resulting from low correlation between ocean color and bacterial contamination. Nevertheless, satellite imagery was shown to be a useful tool for the estimation of the extent of potentially polluted plumes, which was hardly achievable by direct sampling methods (in particular, because the grids of ship-based stations covered only small parts of the plumes detected via synoptic MODIS imagery). In most southern California coastal areas, the zones of bacterial contamination were much smaller than the areas of turbid plumes; an exception was the plume of the Tijuana River, where the zone of bacterial contamination was comparable with the zone of plume detected by ocean color.

Hydrologic and water-quality data for U.S. Coast Guard Support Center Kodiak, Alaska, 1987-89

USGS Publications Warehouse

Glass, R.L.

1996-01-01

Hydrologic and water-quality data were collected at the U.S. Coast Guard Support Center Kodiak on Kodiak Island, Alaska, to determine regional ground-water conditions and if contamination of soils, ground water, or surface water has occurred. Eighteen areas of possible contamination were identified. Ground-water levels, surface- water stages, surface-water discharges, and results of field and laboratory analyses of soil and water samples are presented in tabular form. Many quality-assurance samples had detectable concentrations of methylene chloride and 1,2-dichloroethane, which may be due to sampling or laboratory contamination. Concentrations were as great as 5.9 micrograms per liter for methylene chloride and 2.6 micrograms per liter for 1,2-dichloroethane. Excluding 1,2-dichloroethane, most soil, ground-water, and surface-water samples contained no detectable concentrations of the organic constituents that were analyzed. Chemical analyses were performed on two lake-bed-material samples and more than 100 soil samples. The median lead concentration was 9.8 milligrams per kilogram. Concentrations of tetrachloroethene were as great as 1.1 milligram per kilogram in soils near a laundry. Water samples were collected from 101 wells. The maximum benzene concentration detected in ground water was 78 micrograms per liter from a well at the air station near a site where aviation fuel was spilled. Wells near a laundry yielded water having concentrations of tetrachloroethene as great as 3,000 micrograms per liter, and vinyl chloride as great as 440 micrograms per liter. A well in a former aviation gasoline storage area yielded water with a concentration of trichloroethene as great as 66 micrograms per liter. Water samples were collected from 59 sites on streams, lakes, or ponds. Surface-water samples had much lower concen- trations of organic compounds; the highest concentration of benzene was 2.2 micrograms per liter in a stream near a former aviation-fuel storage area and the maximum vinyl chloride concentration was 15 micrograms per liter in a stream near a former landfill. Tetrachloroethene and trichloroethene were not detected in any surface-water samples.

A Novel Method for Remote Depth Estimation of Buried Radioactive Contamination.

PubMed

Ukaegbu, Ikechukwu Kevin; Gamage, Kelum A A

2018-02-08

Existing remote radioactive contamination depth estimation methods for buried radioactive wastes are either limited to less than 2 cm or are based on empirical models that require foreknowledge of the maximum penetrable depth of the contamination. These severely limits their usefulness in some real life subsurface contamination scenarios. Therefore, this work presents a novel remote depth estimation method that is based on an approximate three-dimensional linear attenuation model that exploits the benefits of using multiple measurements obtained from the surface of the material in which the contamination is buried using a radiation detector. Simulation results showed that the proposed method is able to detect the depth of caesium-137 and cobalt-60 contamination buried up to 40 cm in both sand and concrete. Furthermore, results from experiments show that the method is able to detect the depth of caesium-137 contamination buried up to 12 cm in sand. The lower maximum depth recorded in the experiment is due to limitations in the detector and the low activity of the caesium-137 source used. Nevertheless, both results demonstrate the superior capability of the proposed method compared to existing methods.

A Novel Method for Remote Depth Estimation of Buried Radioactive Contamination

PubMed Central

2018-01-01

Existing remote radioactive contamination depth estimation methods for buried radioactive wastes are either limited to less than 2 cm or are based on empirical models that require foreknowledge of the maximum penetrable depth of the contamination. These severely limits their usefulness in some real life subsurface contamination scenarios. Therefore, this work presents a novel remote depth estimation method that is based on an approximate three-dimensional linear attenuation model that exploits the benefits of using multiple measurements obtained from the surface of the material in which the contamination is buried using a radiation detector. Simulation results showed that the proposed method is able to detect the depth of caesium-137 and cobalt-60 contamination buried up to 40 cm in both sand and concrete. Furthermore, results from experiments show that the method is able to detect the depth of caesium-137 contamination buried up to 12 cm in sand. The lower maximum depth recorded in the experiment is due to limitations in the detector and the low activity of the caesium-137 source used. Nevertheless, both results demonstrate the superior capability of the proposed method compared to existing methods. PMID:29419759

Detection of contamination on selected apple cultivars using reflectance hyperspectral and multispectral analysis

NASA Astrophysics Data System (ADS)

Mehl, Patrick M.; Chao, Kevin; Kim, Moon S.; Chen, Yud-Ren

2001-03-01

Presence of natural or exogenous contaminations on apple cultivars is a food safety and quality concern touching the general public and strongly affecting this commodity market. Accumulations of human pathogens are usually observed on surface lesions of commodities. Detections of either lesions or directly of the pathogens are essential for assuring the quality and safety of commodities. We are presenting the application of hyperspectral image analysis towards the development of multispectral techniques for the detection of defects on chosen apple cultivars, such as Golden Delicious, Red Delicious, and Gala apples. Separate apple cultivars possess different spectral characteristics leading to different approaches for analysis. General preprocessing analysis with morphological treatments is followed by different image treatments and condition analysis for highlighting lesions and contaminations on the apple cultivars. Good isolations of scabs, fungal and soil contaminations and bruises are observed with hyperspectral imaging processing either using principal component analysis or utilizing the chlorophyll absorption peak. Applications of hyperspectral results to a multispectral detection are limited by the spectral capabilities of our RGB camera using either specific band pass filters and using direct neutral filters. Good separations of defects are obtained for Golden Delicious apples. It is however limited for the other cultivars. Having an extra near infrared channel will increase the detection level utilizing the chlorophyll absorption band for detection as demonstrated by the present hyperspectral imaging analysis

Fecal Contamination on Produce from Wholesale and Retail Food Markets in Dhaka, Bangladesh.

PubMed

Harris, Angela R; Islam, Mohammad Aminul; Unicomb, Leanne; Boehm, Alexandria B; Luby, Stephen; Davis, Jennifer; Pickering, Amy J

2018-01-01

Fresh produce items can become contaminated with enteric pathogens along the supply chain at the preharvest (e.g., irrigation water, soil, fertilizer) or postharvest (e.g., vendor handling or consumer handling) stages. This study assesses the concentrations of fecal indicator bacteria Escherichia coli , enterococci (ENT), and Bacteriodales on surfaces of carrots, eggplants, red amaranth leaves, and tomatoes obtained from both a wholesale market (recently harvested) and neighborhood retail markets in Dhaka, Bangladesh. We detected E. coli in 100% of carrot and red amaranth rinses, 92% of eggplant rinses, and 46% of tomato rinses. Using a molecular microbial source tracking assay, we found that 32% of produce samples were positive for ruminant fecal contamination. Fecal indicator bacteria were more likely to be detected on produce collected in retail markets compared with that in the wholesale market; retail market produce were 1.25 times more likely to have E. coli detected ( P = 0.03) and 1.24 times more likely to have ENT detected ( P = 0.03) as compared with wholesale market produce. Bacteriodales was detected in higher concentrations in retail market produce samples compared with wholesale market produce samples (0.40 log 10 gene copies per 100 cm 2 higher, P = 0.03). Our results suggest that ruminant and general fecal contamination of produce in markets in Dhaka is common, and suggest that unsanitary conditions in markets are an important source of produce fecal contamination postharvest.

Adenylate kinase amplification of ATP bioluminescence for hygiene monitoring in the food and beverage industry.

PubMed

Corbitt, A J; Bennion, N; Forsythe, S J

2000-06-01

Fourteen food residues, Escherichia coli O157:H7 and Staphylococcus aureus on stainless steel surfaces were detected using a combined assay with adenylate kinase as a cellular marker and ATP bioluminescence. The limit of sensitivity ranged from 0.02 to 708 microg for minced meat and broccoli, respectively. Both methods gave the same detection limit (105 cfu) for E. coli and Staph. aureus on stainless steel surfaces. The combined adenylate kinase-ATP assay is applicable to monitor the hygiene of work surfaces, especially those prone to contamination by meat and vegetable residues.

Residential Mercury Contamination in Adobe Brick Homes in Huancavelica, Peru

PubMed Central

Hagan, Nicole; Robins, Nicholas; Hsu-Kim, Heileen; Halabi, Susan; Espinoza Gonzales, Ruben Dario; Richter, Daniel deB.; Vandenberg, John

2013-01-01

This is the first study of adobe brick contamination anywhere in the world. Huancavelica, Peru is the site of historic cinnabar refining and one of the most mercury (Hg) contaminated urban areas in the world. Over 80% of homes in Huancavelica are constructed with adobe bricks made from Hg contaminated soil. In this study we measured total Hg concentrations in adobe brick, dirt floor, surface dust, and air samples from the interior of 60 adobe brick houses located in four neighborhoods. Concentrations of total Hg in adobe bricks, dirt floors, and surface dust ranged from 8.00 to 1070 µg/g, 3.06 to 926 µg/g, and 0.02 to 9.69 µg/wipe, respectively, with statistically significant differences between the four neighborhoods. Concentrations of Hg in adobe brick and dirt floor samples in Huancavelica were orders of magnitude higher than in Ayacucho, a non-mining town in Peru. A strong correlation exists between total Hg concentrations in adobe bricks and dirt floors which confirms that adobe bricks were being made on-site and not purchased from an off-site source. A strong correlation between surface dust and adobe bricks and dirt floors indicates that walls and floors serve as indoor sources of Hg contamination. Elemental Hg vapor concentrations were below detection (<0.5 µg/m3) in most homes; however in homes with detectable levels, concentrations up to 5.1 µg/m3 were observed. No statistically significant differences in Hg vapor measurements were observed between neighborhoods. This study demonstrates that building materials used widely in developing communities, such as adobe bricks, may be a substantial source of residential Hg exposure in silver or gold refining communities where Hg is produced or used for amalgamation in artisanal gold production. PMID:24040399

Calculating Confidence, Uncertainty, and Numbers of Samples When Using Statistical Sampling Approaches to Characterize and Clear Contaminated Areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piepel, Gregory F.; Matzke, Brett D.; Sego, Landon H.

2013-04-27

This report discusses the methodology, formulas, and inputs needed to make characterization and clearance decisions for Bacillus anthracis-contaminated and uncontaminated (or decontaminated) areas using a statistical sampling approach. Specifically, the report includes the methods and formulas for calculating the • number of samples required to achieve a specified confidence in characterization and clearance decisions • confidence in making characterization and clearance decisions for a specified number of samples for two common statistically based environmental sampling approaches. In particular, the report addresses an issue raised by the Government Accountability Office by providing methods and formulas to calculate the confidence that amore » decision area is uncontaminated (or successfully decontaminated) if all samples collected according to a statistical sampling approach have negative results. Key to addressing this topic is the probability that an individual sample result is a false negative, which is commonly referred to as the false negative rate (FNR). The two statistical sampling approaches currently discussed in this report are 1) hotspot sampling to detect small isolated contaminated locations during the characterization phase, and 2) combined judgment and random (CJR) sampling during the clearance phase. Typically if contamination is widely distributed in a decision area, it will be detectable via judgment sampling during the characterization phrase. Hotspot sampling is appropriate for characterization situations where contamination is not widely distributed and may not be detected by judgment sampling. CJR sampling is appropriate during the clearance phase when it is desired to augment judgment samples with statistical (random) samples. The hotspot and CJR statistical sampling approaches are discussed in the report for four situations: 1. qualitative data (detect and non-detect) when the FNR = 0 or when using statistical sampling methods that account for FNR > 0 2. qualitative data when the FNR > 0 but statistical sampling methods are used that assume the FNR = 0 3. quantitative data (e.g., contaminant concentrations expressed as CFU/cm2) when the FNR = 0 or when using statistical sampling methods that account for FNR > 0 4. quantitative data when the FNR > 0 but statistical sampling methods are used that assume the FNR = 0. For Situation 2, the hotspot sampling approach provides for stating with Z% confidence that a hotspot of specified shape and size with detectable contamination will be found. Also for Situation 2, the CJR approach provides for stating with X% confidence that at least Y% of the decision area does not contain detectable contamination. Forms of these statements for the other three situations are discussed in Section 2.2. Statistical methods that account for FNR > 0 currently only exist for the hotspot sampling approach with qualitative data (or quantitative data converted to qualitative data). This report documents the current status of methods and formulas for the hotspot and CJR sampling approaches. Limitations of these methods are identified. Extensions of the methods that are applicable when FNR = 0 to account for FNR > 0, or to address other limitations, will be documented in future revisions of this report if future funding supports the development of such extensions. For quantitative data, this report also presents statistical methods and formulas for 1. quantifying the uncertainty in measured sample results 2. estimating the true surface concentration corresponding to a surface sample 3. quantifying the uncertainty of the estimate of the true surface concentration. All of the methods and formulas discussed in the report were applied to example situations to illustrate application of the methods and interpretation of the results.« less

Contamination sources, serogroups, biofilm-forming ability and biocide resistance of Listeria monocytogenes persistent in tilapia-processing facilities.

PubMed

Vázquez-Sánchez, Daniel; Galvão, Juliana Antunes; Oetterer, Marília

2017-11-01

The major contamination sources, serogroups, biofilm-forming ability and biocide resistance of Listeria monocytogenes persistent in tilapia-processing facilities were assessed. Twenty-five processing-control points were examined twice in two factories, including whole tilapias, frozen fillets, water and food-contact surfaces. L. monocytogenes were detected in 4 and 20% of points of Factory A and B respectively, but at low concentrations. Contamination was due to inadequate handling of tilapias in the slaughter room of Factory A and to the application of ineffective sanitizing procedures in Factory B. Seven strains were characterized by RAPD-PCR using primers HLWL85, OPM-01 and DAF4. Genotypic similarity allowed tracing the contamination source of tilapia fillets in Factory B and detecting a prevalent strain in Brazilian tilapia-processing facilities. The serogroup II (including the serotype 1/2c) was the most frequently found, followed by serogroup I (1/2a) and III (1/2b), whereas the serotype 4b was not detected. All strains showed high biofilm-forming ability on stainless steel and polystyrene, but biofilm formation was positively correlated with the type of origin surface. Biofilms were highly resistant to peracetic acid and sodium hypochlorite, being required doses higher than those recommended by manufacturers to be eradicated. Peracetic acid was more effective than sodium hypochlorite, but the use of disinfectants with similar mechanisms of action increases the risk of cross-resistance. Case-by-case approaches are thus recommended to determine the sources and degree of contamination present in each factory, which would allow applying precise responses to control the persistence of bacterial pathogens such as L. monocytogenes .

Forward Contamination of the Moon and Mars: Implications for Future Life Detection Missions

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Kminek, Gerhard; Rummel, John D.

2004-01-01

NASA and ESA have outlined new visions for solar system exploration that will include a series of lunar robotic missions to prepare for, and support a human return to the Moon, and future human exploration of Mars and other destinations. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require that all spacecraft and instrumentation be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under COSPAR's current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft. Nonetheless, future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future Mars surface exploration plans for a human mission to Mars.

Processing-Dependent and Clonal Contamination Patterns of Listeria monocytogenes in the Cured Ham Food Chain Revealed by Genetic Analysis.

PubMed

Morganti, Marina; Scaltriti, Erika; Cozzolino, Paolo; Bolzoni, Luca; Casadei, Gabriele; Pierantoni, Marco; Foni, Emanuela; Pongolini, Stefano

2016-02-01

The quantitative and qualitative patterns of environmental contamination by Listeria monocytogenes were investigated in the production chain of dry-cured Parma ham. Standard arrays of surfaces were sampled in processing facilities during a single visit per plant in the three compartments of the food chain, i.e., ham production (19 plants) and postproduction, which was divided into deboning (43 plants) and slicing (25 plants) steps. The numbers of sampled surfaces were 384 in ham production, with 25 positive for L. monocytogenes, and 1,084 in postproduction, with 83 positives. Statistical analysis of the prevalence of contaminated surfaces showed that in ham production, contamination was higher at the beginning of processing and declined significantly toward the end, while in postproduction, prevalence rose toward the end of processing. Prevalence was higher in the deboning facilities than in slicing facilities and was dependent on the type of surface (floor/drainage > clothing > equipment). The qualitative pattern of contamination was investigated through an analysis of the survey isolates and a set of isolates derived from routine monitoring, including longitudinal isolations. Pulsed-field gel electrophoresis (PFGE) and whole-genome single-nucleotide polymorphism (SNP) analysis revealed a remarkable clonality of L. monocytogenes within plants, with the detection of 16 plant-specific clones out of 17 establishments with multiple isolates. Repeated detections of clonal isolates >6 months apart were also observed. Six was the maximum number of between-isolate differences in core SNPs observed within these clones. Based on the same six-SNP threshold, three clusters of clonal isolates, shared by six establishments, were also identified. The spread of L. monocytogenes within and between plants, as indicated by its clonal behavior, is a matter of concern for the hygienic management of establishments. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Assessment of soil and water contaminants from selected locations in and near the Idaho Army National Guard Orchard Training Area, Ada County, Idaho, 2001-2003

USGS Publications Warehouse

Parliman, D.J.

2004-01-01

In 2001, the National Guard Bureau and the U.S. Geological Survey began a project to compile hydrogeologic data and determine presence or absence of soil, surface-water, and ground-water contamination at the Idaho Army National Guard Orchard Training Area in southwestern Idaho. Between June 2002 and April 2003, a total of 114 soil, surface-water, ground-water, precipitation, or dust samples were collected from 68 sample sites (65 different locations) in the Orchard Training Area (OTA) or along the vehicle corridor to the OTA. Soil and water samples were analyzed for concentrations of selected total trace metals, major ions, nutrients, explosive compounds, semivolatile organics, and petroleum hydrocarbons. Water samples also were analyzed for concentrations of selected dissolved trace metals and major ions. Distinguishing naturally occurring large concentrations of trace metals, major ions, and nutrients from contamination related to land and water uses at the OTA was difficult. There were no historical analyses for this area to compare with modern data, and although samples were collected from 65 locations in and near the OTA, sampled areas represented only a small part of the complex OTA land-use areas and soil types. For naturally occurring compounds, several assumptions were made?anomalously large concentrations, when tied to known land uses, may indicate presence of contamination; naturally occurring concentrations cannot be separated from contamination concentrations in mid- and lower ranges of data; and smallest concentrations may represent the lowest naturally occurring range of concentrations and (or) the absence of contaminants related to land and water uses. Presence of explosive, semivolatile organic (SVOC), and petroleum hydrocarbon compounds in samples indicates contamination from land and water uses. In areas along the vehicle corridor and major access roads within the OTA, most trace metal, major ion, and nutrient concentrations in soil samples were not in the upper 10th percentile of data, but concentrations of 25 metals, ions, or nutrients were in the upper 10th percentile in a puddle sample near the heavy equipment maneuvering area, MPRC-H. The largest concentrations of tin, ammonia, and nitrite plus nitrate (as nitrogen) in water from the OTA were detected in a sample from this puddle. Petroleum hydrocarbons were the most common contaminant, detected in all soil and surface-water samples. An SVOC, bis (2-ethylhexyl) phthalate, a plasticizer, was detected at a site along the vehicle corridor. In Maneuver Areas within the OTA, many soil samples contained at least one trace metal, major ion, or nutrient in the upper 10th percentile of data, and the largest concentrations of cobalt, iron, mercury, titanium, sodium, ammonia, or total phosphorus were detected in 6 of 13 soil samples outside the Tadpole Lake area. The largest concentrations of aluminum, arsenic, beryllium, nickel, selenium, silver, strontium, thallium, vanadium, chloride, potassium, sulfate, and nitrite plus nitrate were detected in soil samples from the Tadpole Lake area. Water from Tadpole Lake contained the largest total concentrations of 19 trace metals, 4 major ions, and 1 nutrient. Petroleum hydrocarbons were detected in 5 soil samples and water from Tadpole Lake. SVOCs related to combustion of fuel or plasticizers were detected in 1 soil sample. Explosive compounds were detected in 1 precipitation sample.In the Impact Area within the OTA, most soil samples contained at least one trace metal, major ion, or nutrient in the upper 10th percentile of data, and the largest concentrations of barium, chromium, copper, manganese, lead, or orthophosphate were detected in 6 of the 18 soil samples. Petroleum hydrocarbons were detected in 4 soil samples, SVOCs in 6 samples, and explosive compounds in 4 samples. In the mobilization and training equipment site (MATES) compound adjacent to the OTA, all soil and water samples contained at lea

Distribution of volatile organic compounds (VOCs) in surface water, soil, and groundwater within a chemical industry park in Eastern China.

PubMed

Liu, Benhua; Chen, Liang; Huang, Linxian; Wang, Yongseng; Li, Yuehua

2015-01-01

This paper focuses on the distribution of volatile organic compounds (VOCs) in the surface water, soil, and groundwater within a chemical industry park in Eastern China. At least one VOC was detected in each of the 20 sampling sites, and the maximum number of VOCs detected in the surface water, groundwater, and soil were 13, 16, and 14, respectively. Two of the 10 VOCs with elevated concentrations detected in surface water, groundwater, and soil were chloroform and 1,2-dichloroethane. The characteristics of VOCs, which include volatility, boiling point, and solubility, could significantly affect their distribution in surface water, soil, and groundwater. However, due to the direct discharging of chemical industry wastewater into surface water, higher concentrations of VOCs (except chloroform) were detected in surface water than in soil and groundwater. Fortunately, the higher volatility of VOCs prevents the VOCs from impacting groundwater, which helps to maintain a lower concentration of VOCs in the groundwater than in both surface water and soil. This is because pollutants with relatively higher boiling points and lower solubilities have higher detection frequencies in soil, and contaminants with relatively lower boiling points and higher solubilities have higher detection frequencies in water, notably in surface water.

New processes and materials for ultraviolet detection with solid state devices

NASA Technical Reports Server (NTRS)

Chopra, D.

1977-01-01

The three major effects that degrade external responsivity of silicon from the 1/lambda theoretical curve for a quantum detector are: surface reflectance, surface recombination, and junction depth. Since the p-n junction must be very shallow, problems relating to surface are further enhanced. MOS type of processing is necessary. HCl oxides and numerous acid clean-ups are utilized in order to obtain a contamination free surface with low Qss levels. Stringent process controls such as CV shifts, spreading resistance measurements, thickness monitoring etc., are used to analyze the surface contaminations, surface mobile charges, surface concentrations, junction depth, oxide thickness etc. Low surface concentrations of 10 to the 18th atoms/cu cm are achieved by low temperature boron nitride depositions. Shallow junction depths of the order of a few tenths of a micron are achieved by low temperature controlled diffusions. In order to improve breakdown characteristics of these shallow junction devices, field plate and deep diffused p(+) ring geometries are used.

UV gated Raman spectroscopy for standoff detection of explosives

NASA Astrophysics Data System (ADS)

Gaft, M.; Nagli, L.

2008-07-01

Real-time detection and identification of explosives at a standoff distance is a major issue in efforts to develop defense against so-called improvised explosive devices (IED). It is recognized that the only method, which is potentially capable to standoff detection of minimal amounts of explosives is laser-based spectroscopy. LDS technique belongs to trace detection, namely to its micro-particles variety. It is based on commonly held belief that surface contamination was very difficult to avoid and could be exploited for standoff detection. We have applied gated Raman spectroscopy for detection of main explosive materials, both factory and homemade. We developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 m.

Detection of Multi-walled Carbon Nanotubes and Carbon Nanodiscs on Workplace Surfaces at a Small-Scale Producer.

PubMed

Hedmer, Maria; Ludvigsson, Linus; Isaxon, Christina; Nilsson, Patrik T; Skaug, Vidar; Bohgard, Mats; Pagels, Joakim H; Messing, Maria E; Tinnerberg, Håkan

2015-08-01

The industrial use of novel-manufactured nanomaterials such as carbon nanotubes and carbon nanodiscs is increasing globally. Occupational exposure can occur during production, downstream use, and disposal. The health effects of many nanomaterials are not yet fully characterized and to handle nano-objects, their aggregates and agglomerates >100nm (NOAA), a high degree of control measures and personal protective equipment are required. The emission of airborne NOAA during production and handling can contaminate workplace surfaces with dust, which can be resuspended resulting in secondary inhalation exposures and dermal exposures. This study surveys the presence of carbon-based nanomaterials, such as multi-walled carbon nanotubes (MWCNTs) and carbon nanodiscs, as surface contamination at a small-scale producer using a novel tape sampling method. Eighteen different surfaces at a small-scale producer were sampled with an adhesive tape sampling method. The surfaces selected were associated with the production and handling of MWCNT powder in the near-field zone. Surfaces in the far-field zone were also sampled. In addition, tape stripping of the skin was performed on one worker. The tape samples were analysed with scanning electron microscopy to detect the carbon-based NOAA. Air sampling with a personal impactor was also performed on a worker who was producing MWCNTs the same day as the tape samples were collected. MWCNTs were detected in 50% of the collected tape samples and carbon nanodiscs in 17%. MWCNTs and carbon nanodiscs were identified in all parts of the workplace, thus, increasing the risk for secondary inhalation and dermal exposure of the workers. Both airborne MWCNTs and carbon nanodiscs were detected in the personal impactor samples. The tape-strip samples from the worker showed no presence of carbon-containing nanoparticles. Tape sampling is a functional method for detecting surface contamination of carbon-based NOAA and for exposure control during production at potentially any workplace that produces or handles such manufactured nanomaterials. With the tape method, it is possible to monitor if a potential for secondary inhalation exposure or dermal exposure exists through resuspension of dust deposited on workplace surfaces. By means of air sampling, we could confirm that carbon nanodiscs were resuspended into the air at the workplace even though they were not handled during that particular work shift. MWCNTs were detected in the air samples, but can have been derived from either resuspension or from the work tasks with MWCNTs that were performed during the air sampling. Tape sampling is a complementary method to air sampling and together these two methods provide a better view of the hygienic situation in workplaces where NOAA can be emitted into work environments. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Water quality and sources of fecal coliform bacteria in the Meduxnekeag River, Houlton, Maine

USGS Publications Warehouse

Culbertson, Charles W.; Huntington, Thomas G.; Stoeckel, Donald M.; Caldwell, James M.; O'Donnell, Cara

2014-01-01

In response to bacterial contamination in the Meduxnekeag River and the desire to manage the watershed to reduce contaminant sources, the Houlton Band of Maliseet Indians (HBMI) and the U.S. Geological Survey began a cooperative effort to establish a baseline of water-quality data that can be used in future studies and to indicate potential sources of nutrient and bacterial contamination. This study was conducted during the summer of 2005 in the Meduxnekeag River Basin near Houlton, Maine. Continuously recorded specific conductance can be a good indicator for water quality. Specific conductance increased downstream from the town of Houlton, between runoff events, and decreased sharply following major runoff events. Collections of discrete samples during the summer of 2005 indicated seasonal positive concentration-discharge relations for total phosphorus and total nitrogen; these results indicate that storm runoff may mobilize and transport these nutrients from the terrestrial environment to the river. Data collected by the HBMI on fecal coliform bacteria indicated that bacterial contamination enters the Meduxnekeag River from multiple paths including tributaries and surface drains (ditches) in developed areas in Houlton, Maine. The Houlton wastewater treatment discharge was not an important source of bacterial contamination. Bacteroidales-based tests for general fecal contamination (Bac32 marker) were predominantly positive in samples that had excessive fecal contamination as indicated by Enterococci density greater than 104 colony-forming units per 100 millilters. Of the 22 samples tested for Bacteroidales-based markers of human-associated fecal contamination (HF134 and HF183), 8 were positive. Of the 22 samples tested for Bacteroidales-based markers of ruminant-associated fecal contamination (CF128 and CF193), 7 were positive. Human fecal contamination was detected consistently at two sites (surface drains in urban areas in the town of Houlton) and occasionally detected at one site (Moose Brook) but was not detected at other sites. Fecal contamination (as indicated by fecal coliform density) apparently is localized under normal flow conditions with the highest levels restricted to drains in urban areas and to a lesser extent B Stream, Pearce Brook, and Big Brook, all tributaries to the main stem of the Meduxnekeag River. Coliphage were enumerated as an alternate indicator of fecal contamination with the intent of typing the virus into host-associated classes (human or ruminant), as was done for Enterococci; however, insufficient coliphage were isolated to provide more than preliminary indications. In spite of low coliphage enumeration, the preliminary results strengthen the conclusion that the Enterococci data correctly indicated the samples that contained human and ruminant fecal contamination. The finding that contamination was in many of the tributaries following storms in mid-July indicates that storm runoff likely carries fecal contaminants to more locations than runoff under lower flow conditions.

Wipe Sampling Method and Evaluation of Environmental Variables for Assessing Surface Contamination of 10 Antineoplastic Drugs by Liquid Chromatography/Tandem Mass Spectrometry.

PubMed

Colombo, Manuel; Jeronimo, Matthew; Astrakianakis, George; Apte, Chirag; Hon, Chun-Yip

2017-10-01

This paper describes a novel wipe sampling and high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) method capable of simultaneously detecting 10 antineoplastic drugs (5-fluorouracil, oxaliplatin, methotrexate, vindesine, ifosfamide, cyclophosphamide, vincristine, vinblastine, docetaxel, and paclitaxel). The good overall recoveries and sensitivity values of this method along with the comparatively short run time (8 min) allows for its use in routine monitoring in health care facilities. The long-term behavior of the studied drugs on contaminated surfaces and the effect of surface roughness on drug recoveries were studied to gain insights about how these environmental variables influence the detection, cleaning, and occupational exposure of these drugs. Surfaces with higher roughness parameter (Ra) values (rougher) had the lowest recoveries while those with lower Ra (smoother) presented the highest recoveries. Long-term assessments evidence distinctive drug behaviors with oxaliplatin, vindesine, vincristine, and vinblastine being the less persistent drugs (~20% was recovered after 24 h) and docetaxel and paclitaxel the most persistent drugs with recoveries of 40% and 80% after 1 month. This information indicates the importance of collecting ancillary information about drug usage (throughput, timing, cleaning procedures, etc.) to interpret the results in the context of potential exposure. Finally, the method was successfully applied to evaluate trace surface contamination down to the single picogram per square centimeter in multiple work areas within three local health care centers on Vancouver Island, Canada. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Heavy metal contamination and ecological risk assessment in the surface sediments of the coastal area surrounding the industrial complex of Gabes city, Gulf of Gabes, SE Tunisia.

PubMed

El Zrelli, Radhouan; Courjault-Radé, Pierre; Rabaoui, Lotfi; Castet, Sylvie; Michel, Sylvain; Bejaoui, Nejla

2015-12-30

In the present study, the concentrations of 6 trace metals (Hg, Cd, Cu, Pb, Cr and Zn) were assessed in the surface sediments of the central coastal area of Gabes Gulf to determine their contamination status, source, spatial distribution and ecological risks. The ranking of metal contents was found to be Zn>Cd>Cr>Pb>Cu>Hg. Correlation analysis indicated that Cd and Zn derived mainly from the Tunisian Chemical Group phosphogypsum. The other pollutants may originate from other industrial wastes. Metallic contamination was detected in the south of chemical complex, especially in the inter-harbor zone, where the ecological risk of surface sediments is the highest, implying potential negative impacts of industrial pollutants. The spatial distribution of pollutants seems to be due to the effect of harbor installations and coastal currents. The metallic pollution status of surface sediments of Gabes Gulf is obvious, very worrying and requires rapid intervention. Copyright © 2015 Elsevier Ltd. All rights reserved.

Source tracking of leaky sewers: a novel approach combining fecal indicators in water and sediments.

PubMed

Guérineau, Hélène; Dorner, Sarah; Carrière, Annie; McQuaid, Natasha; Sauvé, Sébastien; Aboulfadl, Khadija; Hajj-Mohamad, Mariam; Prévost, Michèle

2014-07-01

In highly urbanized areas, surface water and groundwater are particularly vulnerable to sewer exfiltration. In this study, as an alternative to Microbial Source Tracking (MST) methods, we propose a new method combining microbial and chemical fecal indicators (Escherichia coli (E. coli)) and wastewater micropollutants (WWMPs) analysis both in water and sediment samples and under different meteorological conditions. To illustrate the use of this method, wastewater exfiltration and subsequent infiltration were identified and quantified by a three-year field study in an urban canal. The gradients of concentrations observed suggest that several sources of fecal contamination of varying intensity may be present along the canal, including feces from resident animal populations, contaminated surface run-off along the banks and under bridge crossings, release from contaminated banks, entrainment of contaminated sediments, and most importantly sewage exfiltration. Calculated exfiltration-infiltration volumes varied between 0.6 and 15.7 m(3)/d per kilometer during dry weather, and between 1.1 and 19.5 m(3)/d per kilometer during wet weather. WWMPs were mainly diluted and degraded below detection limits in water. E. coli remains the best exfiltration indicator given a large volume of dilution and a high abundance in the wastewater source. WWMPs are effective for detecting cumulated contamination in sediments from a small volume source and are particularly important because E. coli on its own does not allow source tracking. Copyright © 2014 Elsevier Ltd. All rights reserved.

Four passive sampling elements (quatrefoil)--I. Monitoring radon and its progeny by surface-contamination monitors.

PubMed

Tommasino, L; Tokonami, S

2011-05-01

Four passive sampling elements (quatrefoil) have been recently developed, which transform airborne radionuclides into surface-bound radionuclides. These samplers, once exposed, result in thin radiation sources that can be detected by any real-time or passive detector. In particular, by using a large collecting-area sampler with a low surface density (g cm(-2)), it is possible to measure radon and its decay products by beta surface-contamination monitors, which are rarely used for these applications. The results obtained to date prove that it is finally possible to carry out the measurements of radon (and its decay products) indoors, in soil and in water simply by a Pancake Geiger-Muller counter. Emphasis will be given to those measurements, which are difficult, if not impossible, to carry out with existing technologies.

Influence of land use and watershed characteristics on protozoa contamination in a potential drinking water resources reservoir.

PubMed

Keeley, Ann; Faulkner, Barton R

2008-05-01

Relative changes in the microbial quality of Lake Texoma, on the border of Texas and Oklahoma, were investigated by monitoring protozoan pathogens, fecal indicators, and factors influencing the intensity of the microbiological contamination of surface water reservoirs. The watershed serves rural agricultural communities active in cattle ranching, recreation, and is a potential drinking water source. A total of 193 surface water samples were tested over a 27-month period to determine levels of parasite contamination. The overall occurrence of Cryptosporidium oocysts was higher in both frequency and concentration than Giardia cysts. Cryptosporidium oocysts were found in 99% and Giardia cysts in 87% of the samples. Although Cryptosporidium and Giardia occurrence were significantly but not strongly correlated, all other correlation coefficients including turbidity and total dissolved solids were non-significant. Statistically supportable seasonal variations were found suggesting that Cryptosporidium and Giardia were higher in summer and fall than in other seasons of the year. While Cryptosporidium levels were correlated with rainfall, this was not the case with Giardia. The maximum numbers for both protozoan parasites were detected from a site impacted by cattle ranching during calving season. Restriction fragment length polymorphism analysis was used for confirmation of Cryptosporidium in surface waters influenced by agricultural discharges. As we had expected, oocysts were of the bovine type indicating that the Cryptosporidium parvum detected in surface waters perhaps came from cattle living in the watershed.

Label-Free QCM Immunosensor for the Detection of Ochratoxin A

PubMed Central

Ertekin, Özlem; Laguna, Duygu Ercan; Özen, Fehime Şeyma; Öztürk, Zafer Ziya; Öztürk, Selma

2018-01-01

Ochratoxin A (OTA) is a potent mycotoxin that poses a risk in food and feed moieties and subject to worldwide regulation. Laboratory-based analytical methods are traditionally employed for reliable OTA quantification, but these methods cannot provide rapid and on-site analysis, where biosensors fill this gap. In this study a label-free quartz crystal microbalance (QCM)-based immunosensor for the detection of OTA, which is one of the most important small molecule contaminants, was developed by direct immobilization of OTA to amine-bearing sensor surfaces using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) chemistry. The protein-free sensor surface enabled regeneration of sensor surface with 50 mM NaOH and 1% SDS up to 13 times without loss of performance, which would disrupt a protein-containing sensor surface. We developed a QCM immunosensor using the developed sensor surface with a 17.2–200 ng/mL detection range which can be used for on-site detection of feedstuffs. PMID:29641432

Label-Free QCM Immunosensor for the Detection of Ochratoxin A.

PubMed

Pirinçci, Şerife Şeyda; Ertekin, Özlem; Laguna, Duygu Ercan; Özen, Fehime Şeyma; Öztürk, Zafer Ziya; Öztürk, Selma

2018-04-11

Ochratoxin A (OTA) is a potent mycotoxin that poses a risk in food and feed moieties and subject to worldwide regulation. Laboratory-based analytical methods are traditionally employed for reliable OTA quantification, but these methods cannot provide rapid and on-site analysis, where biosensors fill this gap. In this study a label-free quartz crystal microbalance (QCM)-based immunosensor for the detection of OTA, which is one of the most important small molecule contaminants, was developed by direct immobilization of OTA to amine-bearing sensor surfaces using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) chemistry. The protein-free sensor surface enabled regeneration of sensor surface with 50 mM NaOH and 1% SDS up to 13 times without loss of performance, which would disrupt a protein-containing sensor surface. We developed a QCM immunosensor using the developed sensor surface with a 17.2-200 ng/mL detection range which can be used for on-site detection of feedstuffs.

In situ bioremediation of an underground diesel fuel spill: A case history

NASA Astrophysics Data System (ADS)

Frankenberger, W. T.; Emerson, K. D.; Turner, D. W.

1989-05-01

In the winter months of 1983, approximately 1000 gallons of diesel fuel had flowed along an asphalt parking lot of a commercial establishment towards a surface drain near an open creek. Investigations led to the discovery of an underground storage tank leaking diesel fuel. Exploratory borings showed that contamination was near the surface horizon and the capillary zone of the water table. Hydrocarbon quantities ranged up to 1500 mg/kg of soil. The plume continued to move in an eastward direction toward the surface water of the creek. A laboratory study indicated relatively high numbers of hydrocarbon-oxidizing organisms relative to glucose-utilizing microorganisms in the unsaturated vadose zone. Bioreclamation was initiated in April 1984 by injecting nutrients (nitrogen and phosphorus) and hydrogen peroxide and terminated in October 1984 upon no detection (<1 mg/kg) of hydrocarbons. A verification boring within the vicinity of the contaminated plume confirmed that residual contamination had attained background levels. The monitoring program was terminated in January 1987.

Water-Quality Data for Pharmaceuticals and Other Organic Wastewater Contaminants in Ground Water and in Untreated Drinking Water Sources in the United States, 2000-01

USGS Publications Warehouse

Barnes, Kimberlee K.; Kolpin, Dana W.; Focazio, Michael J.; Furlong, Edward T.; Meyer, Michael T.; Zaugg, Steven D.; Haack, Sheridan K.; Barber, Larry B.; Thurman, E. Michael

2008-01-01

The five most frequently detected compounds in samples collected from ambient ground-water sites are N,N-diethyltoluamide (35 percent, insect repellant), bisphenol A (30 percent, plasticizer), tri(2-chloroethy) phosphate (30 percent, fire retardant), sulfamethoxazole (23 percent, veterinary and human antibiotic), and 4-octylphenol monoethoxylate (19 percent, detergent metabolite). The five most frequently detected organic wastewater contaminants in samples of untreated drinking water from surface-water sources are cholesterol (59 percent, natural sterol), metolachlor (53 percent, herbicide), cotinine (51 percent, nicotine metabolite), β-sitosterol (37 percent, natural plant sterol), and 1,7-dimethylxanthine (27 percent, caffeine metabolite). The five most frequently detected organic wastewater contaminants in samples of untreated drinking water from ground-water sources are tetrachloroethylene (24 percent, solvent), carbamazepine (20 percent, pharmaceutical), bisphenol A (20 percent, plasticizer), 1,7-dimethylxanthine (16 percent, caffeine metabolite), and tri(2-chloroethyl) phosphate (12 percent, fire retardant).

Effects of electrolyzed oxidizing water on reducing Listeria monocytogenes contamination on seafood processing surfaces.

PubMed

Liu, Chengchu; Duan, Jingyun; Su, Yi-Cheng

2006-02-15

The effects of electrolyzed oxidizing (EO) water on reducing Listeria monocytogenes contamination on seafood processing surfaces were studied. Chips (5 x 5 cm(2)) of stainless steel sheet (SS), ceramic tile (CT), and floor tile (FT) with and without crabmeat residue on the surface were inoculated with L. monocytogenes and soaked in tap or EO water for 5 min. Viable cells of L. monocytogenes were detected on all chip surfaces with or without crabmeat residue after being held at room temperature for 1 h. Soaking contaminated chips in tap water resulted in small-degree reductions of the organism (0.40-0.66 log cfu/chip on clean surfaces and 0.78-1.33 log cfu/chip on dirty surfaces). Treatments of EO water significantly (p<0.05) reduced L. monocytogenes on clean surfaces (3.73 log on SS, 4.24 log on CT, and 5.12 log on FT). Presence of crabmeat residue on chip surfaces reduced the effectiveness of EO water on inactivating Listeria cells. However, treatments of EO water also resulted in significant reductions of L. monocytogenes on dirty surfaces (2.33 log on SS and CT and 1.52 log on FT) when compared with tap water treatments. The antimicrobial activity of EO water was positively correlated with its chlorine content. High oxidation-reduction potential (ORP) of EO water also contributed significantly to its antimicrobial activity against L. monocytogenes. EO water was more effective than chlorine water on inactivating L. monocytogenes on surfaces and could be used as a chlorine alternative for sanitation purpose. Application of EO water following a thorough cleaning process could greatly reduce L. monocytogenes contamination in seafood processing environments.

PCR detection of groundwater bacteria associated with colloidal transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cruz-Perez, P.; Stetzenbach, L.D.; Alvarez, A.J.

1996-02-29

Colloidal transport may increase the amount of contaminant material than that which could be transported by water flow alone. The role of colloids in groundwater contaminant transport is complicated and may involve many different processes, including sorption of elements onto colloidal particles, coagulation/dissolution, adsorption onto solid surfaces, filtration, and migration. Bacteria are known to concentrate minerals and influence the transport of compounds in aqueous environments and may also serve as organic colloids, thereby influencing subsurface transport of radionuclides and other contaminants. The initial phase of the project consisted of assembling a list of bacteria capable of sequestering or facilitating mineralmore » transport. The development and optimization of the PCR amplification assay for the detection of the organisms of interest, and the examination of regional groundwaters for those organisms, are presented for subsequent research.« less

Public health assessment for USMC Marine Corps Recruit Depot (a/k/a Parris Island Marine Corps Recruit Depot), Parris Island, Beaufort County, South Carolina, Region 4. Cerclis No. SC6170022762

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-09-12

Marine Corps Recruit Depot, (MCRD) Parris Island was proposed for listing on U.S. Environmental Protection Agency`s National Priorities List in August 1994. We identified two areas where chemical contaminants in soil entered the surface water wetland areas and bioaccumulated in edible fish and shellfish species: (1) contaminated fish and shellfish at the Causeway Landfill (Site 3) and (2) contaminated shellfish near the Rifle Range. These exposure situations pose no apparent public health hazard due to the low levels of contaminants detected in fish and shellfish. However, because the landfill has no impermeable cap nor leachate collection system, it is notmore » known whether contaminants in fish and shellfish will increase over time. The remaining 57 contaminated areas pose no public health hazard because people are not coming in contact with contaminants.« less

Recoveries of trace pseudoephedrine and methamphetamine residues from impermeable household surfaces: implications for sampling methods used during remediation of clandestine methamphetamine laboratories.

PubMed

Abdullah, A F Lim; Miskelly, Gordon M

2010-04-15

Evaluation of the risk posed by contaminants present during and after decontamination of clandestine methamphetamine laboratories requires a connection between the levels of contaminants measured and those actually present at the scene. The recoveries of pseudoephedrine and methamphetamine from glass, stainless steel, and a range of impermeable surfaces likely to be found in a clandestine laboratory were examined, using GC-MS of derivatized samples as the analytical method. When surfaces had been cleaned prior to drug deposition, wiping with water-dampened filter paper can recover 60-80% of pseudoephedrine immediately after deposition, and at least 50% of the pseudoephedrine still present on a surface after 2 days when deposited at a surface concentration of 2.5 microg/100 cm(2). Wiping with methanol-dampened filter paper could recover 60-90% of the methamphetamine immediately after deposition, and could recover at least 50-60% of the methamphetamine still present after 2 days when 0.6 microg/100 cm(2) was initially deposited on the surface. Recoveries were lower for surfaces that had not been pre-cleaned. Methamphetamine and pseudoephedrine showed significant volatility in both the free base and hydrochloride forms, with experiments in an enclosed format showing up to half the recovered drug being present on a glass plate held about 4mm above a substrate contaminated with one of the drugs at the above surface concentrations after 2 days. It is therefore important to remove any visible bulk contaminants and remove obvious pseudoephedrine or methamphetamine-contaminated surfaces prior to heating, ventilation or sealing of a clandestine laboratory to avoid redistribution of material around the site. A revised method for pseudoephedrine analysis was developed that could also detect the pseudoephedrine-formaldehyde adduct that can form from trace pseudoephedrine present at clandestine laboratories. (c) 2009 Elsevier B.V. All rights reserved.

Spread of Mycobacterium avium subsp. paratuberculosis through soil and grass on a mouflon (Ovis aries) pasture.

PubMed

Kaevska, Marija; Lvoncik, S; Lamka, J; Pavlik, I; Slana, I

2014-10-01

The aims of this study were to describe spatial contamination of the environment on a mouflon pasture, as well as to assess the contamination of grass and roots after surface contamination and in depth contamination with feces and buried tissues from animals infected with Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis). Samples of soil, roots, and aerial parts of plants were collected from different locations inside the mouflon pasture, and one control sample site was chosen outside the area where the animals are living. M. a. paratuberculosis DNA was present in all the examined sites and was more often detected in roots than in soil. DNA was detected at up to 80 cm of depth and was spatially more widespread than the initial hypothesis of M. a. paratuberculosis leaching vertically into deeper layers of soil. This study broadens our knowledge of the spread and persistence of M. a. paratuberculosis in an environment with highly infected animals.

Observation of a brine layer on an ice surface with an environmental scanning electron microscope at higher pressures and temperatures.

PubMed

Krausko, Ján; Runštuk, Jiří; Neděla, Vilém; Klán, Petr; Heger, Dominik

2014-05-20

Observation of a uranyl-salt brine layer on an ice surface using backscattered electron detection and ice surface morphology using secondary-electron detection under equilibrium conditions was facilitated using an environmental scanning electron microscope (ESEM) at temperatures above 250 K and pressures of hundreds of Pa. The micrographs of a brine layer over ice grains prepared by either slow or shock freezing provided a complementary picture of the contaminated ice grain boundaries. Fluorescence spectroscopy of the uranyl ions in the brine layer confirmed that the species exists predominately in the solvated state under experimental conditions of ESEM.

Handheld hyperspectral imager for standoff detection of chemical and biological aerosols

NASA Astrophysics Data System (ADS)

Hinnrichs, Michele; Jensen, James O.; McAnally, Gerard

2004-02-01

Pacific Advanced Technology has developed a small hand held imaging spectrometer, Sherlock, for gas leak and aerosol detection and imaging. The system is based on a patent technique that uses diffractive optics and image processing algorithms to detect spectral information about objects in the scene of the camera (IMSS Image Multi-spectral Sensing). This camera has been tested at Dugway Proving Ground and Dstl Porton Down facility looking at Chemical and Biological agent simulants. The camera has been used to investigate surfaces contaminated with chemical agent simulants. In addition to Chemical and Biological detection the camera has been used for environmental monitoring of green house gases and is currently undergoing extensive laboratory and field testing by the Gas Technology Institute, British Petroleum and Shell Oil for applications for gas leak detection and repair. The camera contains an embedded Power PC and a real time image processor for performing image processing algorithms to assist in the detection and identification of gas phase species in real time. In this paper we will present an over view of the technology and show how it has performed for different applications, such as gas leak detection, surface contamination, remote sensing and surveillance applications. In addition a sampling of the results form TRE field testing at Dugway in July of 2002 and Dstl at Porton Down in September of 2002 will be given.

Metsulfuron in Surface Groundwater of a North Florida Flatwoods

Treesearch

J.L. Michael; D.G. Neary; J. Fischer; H. Gibbs

1991-01-01

A 4 ha Florida flatwcods pine site was monitored for surface groundwater contamination following application of 0.084 kg ai/ha (1.2 oz metsulfuron/ac) in 140 liters of water carrier per hectare. Treatment was applied in November 1989. An HPIC analytical prccedure is presentedwhich has a detection limit of 1 mg m-3 (1 ppb). A total of 24...

Surface immunoglobulin on cultured foetal mouse thymocytes

PubMed Central

Haustein, D.; Mandel, T. E.

1979-01-01

Organ cultures of 14–15 day foetal mouse thymus were used as a source of non-neoplastic differentiating T cells, free of contaminating B cells. Viable cells obtained from such cultured thymuses were radio-iodinated and immunoglobulins (Ig) were isolated by co-precipitation from the 125I-labelled cell-surface proteins released during 1 h of incubation at 37°. The precipitates, both reduced and unreduced, were then analysed by polyacrylamide gel electrophoresis. The unreduced material migrated in a 5% gel as a single peak with a mobility slightly faster than that of mouse IgG. After reduction, however, two peaks were obtained (in a 10% gel), one corresponding in migration to mouse light chain and the other which moved slightly faster than mouse μ chain. This pattern was identical with that previously seen for both surface Ig of normal mouse thymocytes and neoplastic T lymphoma cells. Uncultured, 15 day foetal thymocytes did not produce any detectable co-precipitated cell surface material. Ig detected in these experiments was therefore produced during in vitro culture by non-neoplastic T cells in a system free of contaminating B cells and mouse serum proteins. PMID:315364

Window flaw detection by backscatter lighting

NASA Technical Reports Server (NTRS)

Crockett, L. K.; Minton, F. R.

1978-01-01

Portable fiber-optic probe detects tiny flaws in transparent materials. Probe transmits light through surface to illuminate interior of material by backscattering off its edges. Light-sensitive contact paper records scratch pattern. Technique can be used for rapid visual checks. Flexible fiber optics are safely used in explosive or flammable areas; they present no hazard of breakage or contamination in controlled environments.

A Filter-based Surface Enhanced Raman Spectroscopic Assay for Rapid Detection of Chemical Contaminants.

PubMed

Gao, Siyue; Glasser, Jessica; He, Lili

2016-02-19

We demonstrate a method to fabricate highly sensitive surface-enhanced Raman spectroscopic (SERS) substrates using a filter syringe system that can be applied to the detection of various chemical contaminants. Silver nanoparticles (Ag NPs) are synthesized via reduction of silver nitrate by sodium citrate. Then the NPs are aggregated by sodium chloride to form nanoclusters that could be trapped in the pores of the filter membrane. A syringe is connected to the filter holder, with a filter membrane inside. By loading the nanoclusters into the syringe and passing through the membrane, the liquid goes through the membrane but not the nanoclusters, forming a SERS-active membrane. When testing the analyte, the liquid sample is loaded into the syringe and flowed through the Ag NPs coated membrane. The analyte binds and concentrates on the Ag NPs coated membrane. Then the membrane is detached from the filter holder, air dried and measured by a Raman instrument. Here we present the study of the volume effect of Ag NPs and sample on the detection sensitivity as well as the detection of 10 ppb ferbam and 1 ppm ampicillin using the developed assay.

Distribution of Archaeal Communities along the Coast of the Gulf of Finland and Their Response to Oil Contamination

PubMed Central

Yan, Lijuan; Yu, Dan; Hui, Nan; Naanuri, Eve; Viggor, Signe; Gafarov, Arslan; Sokolov, Sergei L.; Heinaru, Ain; Romantschuk, Martin

2018-01-01

The Baltic Sea is vulnerable to environmental changes. With the increasing shipping activities, the risk of oil spills remains high. Archaea are widely distributed in many environments. However, the distribution and the response of archaeal communities to oil contamination have rarely been investigated in brackish habitats. Hence, we conducted a survey to investigate the distribution, diversity, composition, and species interactions of indigenous archaeal communities at oil-contaminated sites along the coast of the Gulf of Finland (GoF) using high-throughput sequencing. Surface water and littoral sediment samples were collected at presumably oil-contaminated (oil distribution facilities) and clean sites along the coastline of the GoF in the winter 2015 and the summer 2016. Another three samples of open sea surface water were taken as offshore references. Of Archaea, Euryarchaeota dominated in the surface water and the littoral sediment of the coast of the GoF, followed by Crenarchaeota (including Thaumarchaeota, Thermoprotei, and Korarchaeota based on the Greengenes database used). The unclassified sequences accounted for 5.62% of the total archaeal sequences. Our study revealed a strong dependence of the archaeal community composition on environmental variables (e.g., salinity, pH, oil concentration, TOM, electrical conductivity, and total DNA concentration) in both littoral sediment and coastal water in the GoF. The composition of archaeal communities was season and ecosystem dependent. Archaea was highly diverse in the three ecosystems (littoral sediment, coastal water, and open sea water). Littoral sediment harbored the highest diversity of archaea. Oil was often detected in the littoral sediment but rarely detected in water at those presumably contaminated sites. Although the composition of archaeal community in the littoral sediment was sensitive to low-input oil contamination, the unchanged putative functional profiles and increased interconnectivity of the archaeal core species network plausibly revealed resilience and the potential for oil degradation. Halobacteriaceae and putative cytochrome P450 pathways were significantly enriched in the oil-contaminated littoral sediment. The archaeal taxa formed highly interconnected and interactive networks, in which Halobacteriaceae, Thermococcus, and methanogens were the main components, implying a potential relevant trophic connection between hydrocarbon degradation, methanogenesis, sulfate reduction, and/or fermentative growth. PMID:29410652

Identification and management of microbial contaminations in a surface drinking water source.

PubMed

Aström, J; Pettersson, T J R; Stenström, T A

2007-01-01

Microbial contamination of surface waters constitutes a health risk for drinking water consumers which may be lowered by closing the raw water intake. We have evaluated microbial discharge events reported in the river Göta älv, which is used for raw water supply to the city of Göteborg. Elevated levels of faecal indicator bacteria were observed during periods of closed raw water intake. High bacteria levels were, however, also occasionally detected during periods of open intake, probably as a result of microbial discharge far upstream in the river which may be difficult to predict and manage by closing the intake. Accumulated upstream precipitations, resulting in surface runoff and wastewater contaminations in the catchment, correlated positively with the levels of total coliforms, E. coli, intestinal enterococci and sulfite-reducing clostridia. Levels of faecal indicator organisms were negatively correlated to the water temperature due to enhanced survival at lower temperatures. Wastewater discharges from a municipality located just upstream of the water intake resulted in elevated E. coli concentrations downstream at the raw water intake for Göteborg. To improve the prediction of microbial contaminations within the river Göta älv, monitoring data on turbidity and upstream precipitation are of particular importance.

Instruction manual, Optical Effects Module, Model OEM

NASA Technical Reports Server (NTRS)

1975-01-01

The Optical Effects Module Model OEM-1, a laboratory prototype instrument designed for the automated measurement of radiation transmission and scattering through optical samples, is described. The system comprises two main components: the Optical Effects Module Enclosure (OEME) and the Optical Effects Module Electronic Controller and Processor (OEMCP). The OEM is designed for operation in the near UV at approximately 2540A, corresponding to the most intense spectral line activated by the mercury discharge lamp used for illumination. The radiation from this source is detected in transmission and reflection through a number of selectable samples. The basic objective of this operation is to monitor in real time the accretion of possible contamination on the surface of these samples. The optical samples are exposed outside of the OEME proper to define exposure conditions and to separate exposure and measurement environments. Changes in the transmissivity of the sample are attributable to surface contamination or to bulk effects due to radiation. Surface contamination will increase radiation scattering due to Rayleigh-Gans effect or to other phenomena, depending on the characteristics size of the particulate contaminants. Thus, also scattering from the samples becomes a part of the measurement program.

A longitudinal study of Campylobacter distribution in a turkey production chain

PubMed Central

Perko-Mäkelä, Päivikki; Isohanni, Pauliina; Katzav, Marianne; Lund, Marianne; Hänninen, Marja-Liisa; Lyhs, Ulrike

2009-01-01

Background Campylobacter is the most common cause of bacterial enteritis worldwide. Handling and eating of contaminated poultry meat has considered as one of the risk factors for human campylobacteriosis.Campylobacter contamination can occur at all stages of a poultry production cycle. The objective of this study was to determine the occurrence of Campylobacter during a complete turkey production cycle which lasts for 1,5 years of time. For detection of Campylobacter, a conventional culture method was compared with a PCR method. Campylobacter isolates from different types of samples have been identified to the species level by a multiplex PCR assay. Methods Samples (N = 456) were regularly collected from one turkey parent flock, the hatchery, six different commercial turkey farms and from 11 different stages at the slaughterhouse. For the detection of Campylobacter, a conventional culture and a PCR method were used. Campylobacter isolates (n = 143) were identified to species level by a multiplex PCR assay. Results No Campylobacter were detected in either the samples from the turkey parent flock or from hatchery samples using the culture method. PCR detected Campylobacter DNA in five faecal samples and one fluff and eggshell sample. Six flocks out of 12 commercial turkey flocks where found negative at the farm level but only two were negative at the slaughterhouse. Conclusion During the brooding period Campylobacter might have contact with the birds without spreading of the contamination within the flock. Contamination of working surfaces and equipment during slaughter of a Campylobacter positive turkey flock can persist and lead to possible contamination of negative flocks even after the end of the day's cleaning and desinfection. Reduction of contamination at farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of contaminated poultry meat in Finland. Due to the low numbers of Campylobacter in the Finnish turkey production chain, enrichment PCR seems to be the optimal detection method here. PMID:19348687

Vaccination of chickens decreased Newcastle disease virus contamination in eggs.

PubMed

Sá E Silva, Mariana; Susta, Leonardo; Moresco, Kira; Swayne, David E

2016-01-01

Newcastle disease is an important health issue of poultry causing major economic losses and inhibits trade worldwide. Vaccination is used as a control measure, but it is unknown whether vaccination will prevent virus contamination of eggs. In this study, hens were sham-vaccinated or received one or two doses of inactivated LaSota vaccine, followed three weeks later by virulent Newcastle disease virus (NDV) challenge. Eggs were collected daily and shell, albumen and yolk were subjected to virus isolation, as were oral and cloacal swabs at 2 and 4 days post-challenge (dpc). A second experiment evaluated the distribution of the virus in the reproductive tract of non-vaccinates. All vaccinated chickens survived challenge, and the levels of virus shed from cloacal swabs were decreased significantly when compared to shams. In non-vaccinated hens, virus was detected in the ovary and all segments of the oviduct. Yolk, albumen and eggshell surface from eggs laid at day 4 and 5 post-infection by sham-vaccinated hens were positive for NDV, but eggs from LaSota vaccinated hens lacked virus in internal egg components (i.e. yolk and albumen) and had reduction in the number of positive eggshell surfaces. These results indicate virulent NDV can replicate in the reproductive tract of hens and contaminate internal components of eggs and eggshell surface, but vaccination was able to prevent internal egg contamination, reducing eggshell surface contamination, and reducing shedding from digestive and respiratory tracts in virulent NDV challenged hens.

Distribution of acidic and neutral drugs in surface waters near sewage treatment plants in the lower Great Lakes, Canada.

PubMed

Metcalfe, Chris D; Miao, Xiu-Sheng; Koenig, Brenda G; Struger, John

2003-12-01

Prescription and nonprescription drugs have been detected in rivers and streams in Europe and the United States. Sewage treatment plants (STPs) are an important source of these contaminants, but few data exist on the spatial distribution of drugs in surface waters near STPs. Samples of surface water were collected in the summer and fall of 2000 at open-water sites in the lower Great Lakes (Lake Ontario and Lake Erie), at sites near the two STPs for the city of Windsor (ON, Canada), and at sites in Hamilton Harbour (ON, Canada), an embayment of western Lake Ontario that receives discharges from several STPs. In a follow-up study in the summer of 2002, samples of surface water and final effluent from adjacent STPs were collected from sites in Hamilton Harbour and Windsor. In addition, surface water and STP effluent samples were collected in Peterborough (ON, Canada). All samples of surface water and STP effluents were analyzed for selected acidic and neutral drugs. In the survey of Hamilton Harbour and Windsor conducted in 2000, acidic drugs and the antiepileptic drug carbamazepine were detected at ng/L concentrations at sites that were up to 500 m away from the STP, but the hydrological conditions of the receiving waters strongly influenced the spatial distribution of these compounds. Drugs were not detected at open-water locations in western Lake Erie or in the Niagara River near the municipality of Niagara-on-the-Lake (ON, Canada). However, clofibric acid, ketoprofen, fenoprofen, and carbamazepine were detected in samples collected in the summer of 2000 at sites in Lake Ontario and at a site in the Niagara River (Fort Erie, ON, Canada) that were relatively remote from STP discharges. Follow-up studies in the summer of 2002 indicated that concentrations of acidic and neutral drugs in surface waters near the point of sewage discharge into the Little River (ON, Canada) STP were approximately equal to the concentrations in the final effluent from the STP. Caffeine and cotinine, a metabolite of nicotine, were generally present in STP effluents and surface waters contaminated by drugs. The antidepressant fluoxetine and the antibiotic trimethoprom were also detected in most STP effluents and some surface water samples. For the first time, the lipid regulating drug atorvastatin was detected in samples of STP effluent and surface water.

Transfer efficiencies of pesticides from household flooring surfaces to foods.

PubMed

Rohrer, Cynthia A; Hieber, Thomas E; Melnyk, Lisa J; Berry, Maurice R

2003-11-01

The transfer of pesticides from household surfaces to foods was measured to determine the degree of excess dietary exposure that occurs when children's foods contact contaminated surfaces prior to being eaten. Three household flooring surfaces (ceramic tile, hardwood, and carpet) were contaminated with an aqueous emulsion of commercially available pesticides (diazinon, heptachlor, malathion, chlorpyrifos, isofenphos, and cis- and trans-permethrin) frequently found in residential environments. A surface wipe method, as typically used in residential exposure studies, was used to measure the pesticides available on the surfaces as a basis for calculating transfer efficiency to the foods. Three foods (apple, bologna, and cheese) routinely handled by children before eating were placed on the contaminated surfaces and transfers of pesticides were measured after 10 min contact. Other contact durations (1 and 60 min) and applying additional contact force (1500 g) to the foods were evaluated for their impact on transferred pesticides. More pesticides transferred to the foods from the hard surfaces, that is, ceramic tile and hardwood flooring, than from carpet. Mean transfer efficiencies for all pesticides to the three foods ranged from 24% to 40% from ceramic tile and 15% to 29% from hardwood, as compared to mostly non-detectable transfers from carpet. Contact duration and applied force notably increased pesticide transfer. The mean transfer efficiency for the seven pesticides increased from around 1% at 1 min to 55- 83% when contact duration was increased to 60 min for the three foods contacting hardwood flooring. Mean transfer efficiency for 10-min contact increased from 15% to 70% when a 1500 g force was applied to bologna placed on hardwood flooring. Contamination of food occurs from contact with pesticide-laden surfaces, thus increasing the potential for excess dietary exposure of children.

Quantifying Diffuse Contamination: Method and Application to Pb in Soil.

PubMed

Fabian, Karl; Reimann, Clemens; de Caritat, Patrice

2017-06-20

A new method for detecting and quantifying diffuse contamination at the continental to regional scale is based on the analysis of cumulative distribution functions (CDFs). It uses cumulative probability (CP) plots for spatially representative data sets, preferably containing >1000 determinations. Simulations demonstrate how different types of contamination influence elemental CDFs of different sample media. It is found that diffuse contamination is characterized by a distinctive shift of the low-concentration end of the distribution of the studied element in its CP plot. Diffuse contamination can be detected and quantified via either (1) comparing the distribution of the contaminating element to that of an element with a geochemically comparable behavior but no contamination source (e.g., Pb vs Rb), or (2) comparing the top soil distribution of an element to the distribution of the same element in subsoil samples from the same area, taking soil forming processes into consideration. Both procedures are demonstrated for geochemical soil data sets from Europe, Australia, and the U.S.A. Several different data sets from Europe deliver comparable results at different scales. Diffuse Pb contamination in surface soil is estimated to be <0.5 mg/kg for Australia, 1-3 mg/kg for Europe, and 1-2 mg/kg, or at least <5 mg/kg, for the U.S.A. The analysis presented here also allows recognition of local contamination sources and can be used to efficiently monitor diffuse contamination at the continental to regional scale.

Examining factors that influence the effectiveness of cleaning antineoplastic drugs from drug preparation surfaces: a pilot study.

PubMed

Hon, Chun-Yip; Chua, Prescillia Ps; Danyluk, Quinn; Astrakianakis, George

2014-06-01

Occupational exposure to antineoplastic drugs has been documented to result in various adverse health effects. Despite the implementation of control measures to minimize exposure, detectable levels of drug residual are still found on hospital work surfaces. Cleaning these surfaces is considered as one means to minimize the exposure potential. However, there are no consistent guiding principles related to cleaning of contaminated surfaces resulting in hospitals to adopt varying practices. As such, this pilot study sought to evaluate current cleaning protocols and identify those factors that were most effective in reducing contamination on drug preparation surfaces. Three cleaning variables were examined: (1) type of cleaning agent (CaviCide®, Phenokil II™, bleach and chlorhexidine), (2) application method of cleaning agent (directly onto surface or indirectly onto a wipe) and (3) use of isopropyl alcohol after cleaning agent application. Known concentrations of antineoplastic drugs (either methotrexate or cyclophosphamide) were placed on a stainless steel swatch and then, systematically, each of the three cleaning variables was tested. Surface wipes were collected and quantified using high-performance liquid chromatography-tandem mass spectrometry to determine the percent residual of drug remaining (with 100% being complete elimination of the drug). No one single cleaning agent proved to be effective in completely eliminating all drug contamination. The method of application had minimal effect on the amount of drug residual. In general, application of isopropyl alcohol after the use of cleaning agent further reduced the level of drug contamination although measureable levels of drug were still found in some cases.

How Reliable Are ATP Bioluminescence Meters in Assessing Decontamination of Environmental Surfaces in Healthcare Settings?

PubMed Central

Omidbakhsh, Navid; Ahmadpour, Faraz; Kenny, Nicole

2014-01-01

Background Meters based on adenosine triphosphate (ATP) bioluminescence measurements in relative light units (RLU) are often used to rapidly assess the level of cleanliness of environmental surfaces in healthcare and other settings. Can such ATP measurements be adversely affected by factors such as soil and cleaner-disinfectant chemistry? Objective This study tested a number of leading ATP meters for their sensitivity, linearity of the measurements, correlation of the readings to the actual microbial contamination, and the potential disinfectant chemicals’ interference in their readings. Methods First, solutions of pure ATP in various concentrations were used to construct a standard curve and determine linearity and sensitivity. Serial dilutions of a broth culture of Staphylococcus aureus, as a representative nosocomial pathogen, were then used to determine if a given meter’s ATP readings correlated with the actual CFUs. Next, various types of disinfectant chemistries were tested for their potential to interfere with the standard ATP readings. Results All four ATP meters tested herein demonstrated acceptable linearity and repeatability in their readings. However, there were significant differences in their sensitivity to detect the levels of viable microorganisms on experimentally contaminated surfaces. Further, most disinfectant chemistries tested here quenched the ATP readings variably in different ATP meters evaluated. Conclusions Apart from their limited sensitivity in detecting low levels of microbial contamination, the ATP meters tested were also prone to interference by different disinfectant chemistries. PMID:24940751

Laboratory evaluation of disposable and reusable disinfectant cloths for cleaning food contact surfaces.

PubMed Central

Tebbutt, G. M.

1988-01-01

A comparison of five methods of cleaning Formica surfaces contaminated with bacteria dried in milk has been carried out. A standardized procedure was developed, and impression plates were found to be at least as sensitive as a swab-rinse method for detecting bacteria on the surfaces. The most satisfactory results were obtained with one type of disposable alcohol-impregnated wipe and with a detergent/hypochlorite solution applied with paper. A reusable cloth impregnated with disinfectant initially performed well against all test organisms, but was less reliable against Staphylococcus aureus and Streptococcus faecalis, after the cloth had been used and rinsed several times. The importance of introducing methods to reduce the high risk of cross-contamination presently associated with the use of wiping cloths in catering premises is stressed. PMID:3141202

Towards a rapid and comprehensive microbial detection and identification system for life support and planetary protection applications

NASA Astrophysics Data System (ADS)

Lasseur, Christophe

Long term manned missions of our Russian colleagues have demonstrated the risks associated with microbial contamination. These risks concern both crew health via the metabolic consumables contamination (water, air,.) but and also the hardware degradation. In parallel to these life support issues, planetary protection experts have agreed to place clear specifications of the microbial quality of future hardware landing on extraterrestrial planets as well as elaborate the requirements of contamination for manned missions on surface. For these activities, it is necessary to have a better understanding of microbial activity, to create culture collections and to develop on-line detection tools. . In this respect, over the last 6 years , ESA has supported active scientific research on the choice of critical genes and functions, including those linked to horizontal gene pool of bacteria and its dissemination. In parallel, ESA and European industries have been developing an automated instrument for rapid microbial detection on air and surface samples. Within this paper, we first present the life support and planetary protection requirements, and the state of the art of the instrument development. Preliminary results at breadboard level, including a mock-up view of the final instrument are also presented. Finally, the remaining steps required to reach a functional instrument for planetary hardware integration and life support flight hardware are also presented.

Traces of illegal drugs on body surfaces: indicator for consumption or dealing?

NASA Astrophysics Data System (ADS)

Aberl, Franz; Bonenberger, Johannes; Berg, Ralf-Peter; Zimmermann, Rudolph; Sachs, Hans W.

1997-01-01

Customs investigation and drug enforcement services are interest in a rapid and reliable identification of smugglers and dealers. In contrast workplace testing and traffic controls are aiming at the detection of intoxicated persons via the determination of illegal narcotics in body fluids like urine or blood. DRUGWIPE is a pen size, test strip based immunochemical detector for narcotic contaminations on surfaces. It is extremely simple to apply and takes about two minutes to read test results without depending upon any further technical means. This paper describes the applicability of DRUGWIPE to identify drug smugglers or dealers as well as consumers. With respect to the situation and the initial suspicion the test indicates handling as well as consumption. In cooperation with the Institute for Legal Medicine in Munich suspicious drivers were examined with DRUGWIPE for the abuse of illegal narcotics. Test results from this test series are presented and compared with the results from the blood or urine analysis. The question whether the detected traces of illegal narcotics on the body surface of suspicious drivers are combing transpiration or external contamination are discussed.

Temporal variability of micro-organic contaminants in lowland chalk catchments: New insights into contaminant sources and hydrological processes.

PubMed

Manamsa, K; Lapworth, D J; Stuart, M E

2016-10-15

This paper explores the temporal variation of a broad suite of micro organic (MO) compounds within hydrologically linked compartments of a lowland Chalk catchment, the most important drinking water aquifer in the UK. It presents an assessment of results from relatively high frequency monitoring at a well-characterised site, including the type and concentrations of compounds detected and how they change under different hydrological conditions including exceptionally high groundwater levels and river flow conditions during 2014 and subsequent recovery. This study shows for the first time that within the Chalk groundwater there can be a greater diversity of the MOs compared to surface waters. Within the Chalk 26 different compounds were detected over the duration of the study compared to 17 in the surface water. Plasticisers (0.06-39μg/L) were found to dominate in the Chalk groundwater on 5 visits (38.4%) accounting for 14.5% of detections but contributing highest concentrations whilst other compounds dominated in the surface water. Trichloroethene and atrazine were among the most frequently detected compounds. The limit for the total pesticide concentration detected did not exceed EU/UK prescribed concentration values for drinking water. Emerging organic compounds such as caffeine, which currently do not have water quality limits, were also detected. The low numbers of compounds found within the hyporheic zone highlight the role of this transient interface in the attenuation and breakdown of the MOs, and provision of an important ecosystem service. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

Measurement of surface contamination by certain antineoplastic drugs using high-performance liquid chromatography: applications in occupational hygiene investigations in hospital environments.

PubMed

Rubino, F M; Floridia, L; Pietropaolo, A M; Tavazzani, M; Colombi, A

1999-01-01

Within the context of continuing interest in occupational hygiene of hospitals as workplaces, the authors report the results of a preliminary study on surface contamination by certain antineoplastic drugs (ANDs), recently performed in eight cancer departments of two large general hospitals in Milan, Italy. Since reliable quantitative information on the exposure levels to individual drugs is mandatory to establish a strong interpretative framework for correctly assessing the health risks associated with manipulation of ANDs and rationally advise intervention priorities for exposure abatement, two automated analytical methods were set up using reverse-phase high-performance liquid chromatography for the measurement of contamination by 1) methotrexate (MTX) and 2) the three most important nucleoside analogue antineoplastic drugs (5-fluorouracil 5FU, Cytarabin CYA, Gemcytabin GCA) on surfaces such as those of preparation hoods and work-benches in the pharmacies of cancer wards. The methods are characterized by short analysis time (7 min) under isocratic conditions, by the use of a mobile phase with a minimal content of organic solvent and by high sensitivity, adequate to detect surface contamination in the 5-10 micrograms/m2 range. To exemplify the performance of the analytical methods in the assessment of contamination levels from the target analyte ANDs, data are reported on the contamination levels measured on various surfaces (such as on handles, floor surfaces and window panes, even far from the preparation hood). Analyte concentrations corresponding to 0.8-1.5 micrograms of 5FU were measured on telephones, 0.85-28 micrograms/m2 of CYA were measured on tables, 1.2-1150 micrograms/m2 of GCA on furniture and floors. Spillage fractions between 1-5% of the used ANDs (daily use 5FU 7-13 g; CYA 0.1-7.1 g; GCA 0.2-5 g) were measured on the disposable polythene-backed paper cover sheet of the preparation hood.

Fluorescence Characterization of Clinically-Important Bacteria

PubMed Central

Dartnell, Lewis R.; Roberts, Tom A.; Moore, Ginny; Ward, John M.; Muller, Jan-Peter

2013-01-01

Healthcare-associated infections (HCAI/HAI) represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs) over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of potential problems of background fluorescence masking that of bacteria, but in the case of the microfiber cleaning cloth, imaging techniques could morphologically distinguish between stray strands and bacterial contamination. PMID:24098687

Fluorescence characterization of clinically-important bacteria.

PubMed

Dartnell, Lewis R; Roberts, Tom A; Moore, Ginny; Ward, John M; Muller, Jan-Peter

2013-01-01

Healthcare-associated infections (HCAI/HAI) represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs) over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of potential problems of background fluorescence masking that of bacteria, but in the case of the microfiber cleaning cloth, imaging techniques could morphologically distinguish between stray strands and bacterial contamination.

Small business initiative -- Surface inspection machine infrared (SIMIR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, G.L.; Beecroft, M.

This Cooperative Research and Development Agreement was a one year effort to make the surface inspection machine based on diffuse reflectance infrared spectroscopy (Surface Inspection Machine-Infrared, SIMIR), being developed by Surface Optics Corporation, perform to its highest potential as a practical, portable surface inspection machine. A secondary purpose was to evaluate applications that would serve both the private and the public sector. The design function of the SIMIR is to inspect sandblasted metal surfaces for cleanliness (stains). The system is also capable of evaluating graphite-resin systems for cure and heat damage, and for measuring the effects of moisture exposure onmore » lithium hydride, corrosion on uranium metal, and the constituents of and contamination on wood, paper, and fabrics. Surface Optics Corporation supplied LMES-Y12 with a prototype SOC-400 that was evaluated by LMES-Y12 and rebuilt by Surface Optics to achieve the desired performance. LMES-Y12 subsequently evaluated the instrument against numerous applications including determining part cleanliness at the Corpus Christi Army Depot, demonstrating the ability to detect plasticizers and other organic contaminants on metals to Pantex and LANL personnel, analyzed sandblasted metal contamination standards supplied by NASA-MSFC, and demonstrated to Lockheed Martin Tactical Aircraft, marietta, GA, for analyzing the paint applied to the F-22 Fighter. The instrument also demonstrated the analysis of yarn, fabric, and finish on the textiles.« less

Are luminescent bacteria suitable for online detection and monitoring of toxic compounds in drinking water and its sources?

PubMed

Woutersen, Marjolijn; Belkin, Shimshon; Brouwer, Bram; van Wezel, Annemarie P; Heringa, Minne B

2011-05-01

Biosensors based on luminescent bacteria may be valuable tools to monitor the chemical quality and safety of surface and drinking water. In this review, an overview is presented of the recombinant strains available that harbour the bacterial luciferase genes luxCDABE, and which may be used in an online biosensor for water quality monitoring. Many bacterial strains have been described for the detection of a broad range of toxicity parameters, including DNA damage, protein damage, membrane damage, oxidative stress, organic pollutants, and heavy metals. Most lux strains have sensitivities with detection limits ranging from milligrams per litre to micrograms per litre, usually with higher sensitivities in compound-specific strains. Although the sensitivity of lux strains can be enhanced by various molecular manipulations, most reported detection thresholds are still too high to detect levels of individual contaminants as they occur nowadays in European drinking waters. However, lux strains sensing specific toxic effects have the advantage of being able to respond to mixtures of contaminants inducing the same effect, and thus could be used as a sensor for the sum effect, including the effect of compounds that are as yet not identified by chemical analysis. An evaluation of the suitability of lux strains for monitoring surface and drinking water is therefore provided.

Serotypes and Pulsotypes diversity of Listeria monocytogenes in a beef-processing environment.

PubMed

Camargo, Anderson Carlos; Dias, Mariane Rezende; Cossi, Marcus Vinícius Coutinho; Lanna, Frederico Germano Piscitelli Alvarenga; Cavicchioli, Valéria Quintana; Vallim, Deyse Christina; Pinto, Paulo Sérgio de Arruda; Hofer, Ernesto; Nero, Luís Augusto

2015-04-01

Utensils and equipment from meat-processing facilities are considered relevant cross-contamination points of Listeria monocytogenes to foods, demanding tracking studies to identify their specific origins, and predict proper control. The present study aimed to detect L. monocytogenes in a beef-processing facility, investigating the diversity of serotypes and pulsotypes in order to identify the possible contamination routes. Surface samples from knives (n=26), tables (n=78), and employees hands (n=74) were collected before and during the procedures from a beef-processing facility, in addition to surface samples of end cuts: round (n=32), loin (n=30), and chuck (n=32). All samples were subjected to L. monocytogenes screening according ISO 11.290-1, and the obtained isolates were subjected to serotyping and pulsed-field gel electrophoresis. Listeria spp. were identified in all processing steps, in 61 samples, and L. monocytogenes was detected in 17 samples, not being found only in knives. Eighty-five isolates were identified as L. monocytogenes, from serotypes 1/2c (n=65), 4b (n=13), and 1/2b (n=7), being grouped in 19 pulsotypes. Considering these results, cross-contamination among hands, tables, and beef cuts could be identified. The obtained data indicated the relevance of cross-contamination in the beef-processing facility, and the occurrence of serotypes 1/2b and 4b in beef cuts distributed for retail sale is a public health concern.

Bacterial contamination monitor

NASA Technical Reports Server (NTRS)

Rich, E.; Macleod, N. H.

1973-01-01

Economical, simple, and fast method uses apparatus which detects bacteria by photography. Apparatus contains camera, film assembly, calibrated light bulb, opaque plastic plate with built-in reflecting surface and transparent window section, opaque slide, plate with chemical packages, and cover containing roller attached to handle.

Perfluorinated Compounds: Emerging POPs with Potential Immunotoxicity

EPA Science Inventory

Perfluorinated compounds (PFCs) have been recognized as an important class of environmental contaminants commonly detected in blood samples of both wildlife and humans. These compounds have been in use for more than 60 years as surface treatment chemicals, polymerization aids, an...

Management and modeling: Tools to improve water quality

USDA-ARS?s Scientific Manuscript database

Agricultural, urban and suburban sources contribute to the contamination of surface waters, which has been observed by the detection of pesticides, excess nutrients, industrial pollutants, antibiotics, pharmaceuticals, and personal care products in both natural waters and treated wastewaters. The us...

Florida seagrass habitat evaluation: A comparative survey for chemical quality

EPA Science Inventory

Contaminant concentrations were determined for media associated with 13 Florida seagrass beds. Concentrations of 10 trace metals were more commonly detected in surface water, sediment and two seagrass species than PAHs, pesticides and PCBs. Concentrations of copper and arsenic ...

Stability of bovine coronavirus on lettuce surfaces under household refrigeration conditions.

PubMed

Mullis, Lisa; Saif, Linda J; Zhang, Yongbin; Zhang, Xuming; Azevedo, Marli S P

2012-05-01

Fecal suspensions with an aerosol route of transmission were responsible for a cluster of severe acute respiratory syndrome (SARS) cases in 2003 in Hong Kong. Based on that event, the World Health Organization recommended that research be implemented to define modes of transmission of SARS coronavirus through sewage, feces, food and water. Environmental studies have shown that animal coronaviruses remain infectious in water and sewage for up to a year depending on the temperature and humidity. In this study, we examined coronavirus stability on lettuce surfaces. A cell culture adapted bovine coronavirus, diluted in growth media or in bovine fecal suspensions to simulate fecal contamination was used to spike romaine lettuce. qRT-PCR detected viral RNA copy number ranging from 6.6 × 10⁴ to 1.7 × 10⁶ throughout the experimental period of 30 days. Whereas infectious viruses were detected for at least 14 days, the amount of infectious virus varied, depending upon the diluent used for spiking the lettuce. UV and confocal microscopic observation indicated attachment of residual labeled virions to the lettuce surface after the elution procedure, suggesting that rates of inactivation or detection of the virus may be underestimated. Thus, it is possible that contaminated vegetables may be potential vehicles for coronavirus zoonotic transmission to humans. Published by Elsevier Ltd.

Microbial contamination of mobile phones in a health care setting in Alexandria, Egypt.

PubMed

Selim, Heba Sayed; Abaza, Amani Farouk

2015-01-01

This study aimed at investigating the microbial contamination of mobile phones in a hospital setting. Swab samples were collected from 40 mobile phones of patients and health care workers at the Alexandria University Students' Hospital. They were tested for their bacterial contamination at the microbiology laboratory of the High Institute of Public Health. Quantification of bacteria was performed using both surface spread and pour plate methods. Isolated bacterial agents were identified using standard microbiological methods. Methicillin-resistant Staphylococcus aureus was identified by disk diffusion method described by Bauer and Kirby. Isolated Gram-negative bacilli were tested for being extended spectrum beta lactamase producers using the double disk diffusion method according to the Clinical and Laboratory Standards Institute recommendations. All of the tested mobile phones (100%) were contaminated with either single or mixed bacterial agents. The most prevalent bacterial contaminants were methicillin-resistant S. aureus and coagulase-negative staphylococci representing 53% and 50%, respectively. The mean bacterial count was 357 CFU/ml, while the median was 13 CFU/ml using the pour plate method. The corresponding figures were 2,192 and 1,720 organisms/phone using the surface spread method. Mobile phones usage in hospital settings poses a risk of transmission of a variety of bacterial agents including multidrug-resistant pathogens as methicillin-resistant S. aureus. The surface spread method is an easy and useful tool for detection and estimation of bacterial contamination of mobile phones.

Microbial contamination of mobile phones in a health care setting in Alexandria, Egypt

PubMed Central

Selim, Heba Sayed; Abaza, Amani Farouk

2015-01-01

Aim: This study aimed at investigating the microbial contamination of mobile phones in a hospital setting. Methods: Swab samples were collected from 40 mobile phones of patients and health care workers at the Alexandria University Students’ Hospital. They were tested for their bacterial contamination at the microbiology laboratory of the High Institute of Public Health. Quantification of bacteria was performed using both surface spread and pour plate methods. Isolated bacterial agents were identified using standard microbiological methods. Methicillin-resistant Staphylococcus aureus was identified by disk diffusion method described by Bauer and Kirby. Isolated Gram-negative bacilli were tested for being extended spectrum beta lactamase producers using the double disk diffusion method according to the Clinical and Laboratory Standards Institute recommendations. Results: All of the tested mobile phones (100%) were contaminated with either single or mixed bacterial agents. The most prevalent bacterial contaminants were methicillin-resistant S. aureus and coagulase-negative staphylococci representing 53% and 50%, respectively. The mean bacterial count was 357 CFU/ml, while the median was 13 CFU/ml using the pour plate method. The corresponding figures were 2,192 and 1,720 organisms/phone using the surface spread method. Conclusions: Mobile phones usage in hospital settings poses a risk of transmission of a variety of bacterial agents including multidrug-resistant pathogens as methicillin-resistant S. aureus. The surface spread method is an easy and useful tool for detection and estimation of bacterial contamination of mobile phones. PMID:25699226

The rapid detection of methyl tert-butyl ether (MtBE) in water using a prototype gas sensor system.

PubMed

de Lacy Costello, B P J; Sivanand, P S; Ratcliffe, N M; Reynolds, D M

2005-01-01

The gasoline additive Methyl-tertiary-Butyl Ether (MtBE) is the second most common contaminant of groundwater in the USA and represents an important soil contaminant. This compound has been detected in the groundwater in at least 27 states as a result of leaking underground storage facilities (gasoline storage tanks and pipelines). Since the health effects of MtBE are unclear the potential threat to drinking water supplies is serious. Therefore, the ability to detect MtBE at low levels (ppb) and on-line at high-risk groundwater sites would be highly desirable. This paper reports the use of 'commercial' and metal oxide sensor arrays for the detection of MtBE in drinking and surface waters at low ppb level (microg.L(-1) range). The output responses from some of the sensors were found to correlate well with MtBE concentrations under laboratory conditions.

Assessment of Environmental Contamination with Pathogenic Bacteria at a Hospital Laundry Facility.

PubMed

Michael, Karen E; No, David; Daniell, William E; Seixas, Noah S; Roberts, Marilyn C

2017-11-10

Little is known about exposure to pathogenic bacteria among industrial laundry workers who work with soiled clinical linen. To study worker exposures, an assessment of surface contamination was performed at an industrial laundry facility serving hospitals in Seattle, WA, USA. Surface swab samples (n = 240) from the environment were collected during four site visits at 3-month intervals. These samples were cultured for Clostridium difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). Voluntary participation of 23 employees consisted of nasal swabs for detection of MRSA, observations during work, and questionnaires. Contamination with all three pathogens was observed in both dirty (laundry handling prior to washing) and clean areas (subsequent to washing). The dirty area had higher odds of overall contamination (≥1 pathogen) than the clean area (odds ratio, OR = 18.0, 95% confidence interval 8.9-36.5, P < 0.001). The odds of contamination were high for each individual pathogen: C. difficile, OR = 15.5; MRSA, OR = 14.8; and VRE, OR = 12.6 (each, P < 0.001). The highest odds of finding surface contamination occurred in the primary and secondary sort areas where soiled linens were manually sorted by employees (OR = 63.0, P < 0.001). The study substantiates that the laundry facility environment can become contaminated by soiled linens. Workers who handle soiled linen may have a higher risk of exposure to C. difficile, MRSA, and VRE than those who handle clean linens. Improved protocols for prevention and reduction of environmental contamination were implemented because of this study. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Elimination of Porcine Epidemic Diarrhea Virus in an Animal Feed Manufacturing Facility.

PubMed

Huss, Anne R; Schumacher, Loni L; Cochrane, Roger A; Poulsen, Elizabeth; Bai, Jianfa; Woodworth, Jason C; Dritz, Steve S; Stark, Charles R; Jones, Cassandra K

2017-01-01

Porcine Epidemic Diarrhea Virus (PEDV) was the first virus of wide scale concern to be linked to possible transmission by livestock feed or ingredients. Measures to exclude pathogens, prevent cross-contamination, and actively reduce the pathogenic load of feed and ingredients are being developed. However, research thus far has focused on the role of chemicals or thermal treatment to reduce the RNA in the actual feedstuffs, and has not addressed potential residual contamination within the manufacturing facility that may lead to continuous contamination of finished feeds. The purpose of this experiment was to evaluate the use of a standardized protocol to sanitize an animal feed manufacturing facility contaminated with PEDV. Environmental swabs were collected throughout the facility during the manufacturing of a swine diet inoculated with PEDV. To monitor facility contamination of the virus, swabs were collected at: 1) baseline prior to inoculation, 2) after production of the inoculated feed, 3) after application of a quaternary ammonium-glutaraldehyde blend cleaner, 4) after application of a sodium hypochlorite sanitizing solution, and 5) after facility heat-up to 60°C for 48 hours. Decontamination step, surface, type, zone and their interactions were all found to impact the quantity of detectable PEDV RNA (P < 0.05). As expected, all samples collected from equipment surfaces contained PEDV RNA after production of the contaminated feed. Additionally, the majority of samples collected from non-direct feed contact surfaces were also positive for PEDV RNA after the production of the contaminated feed, emphasizing the potential role dust plays in cross-contamination of pathogen throughout a manufacturing facility. Application of the cleaner, sanitizer, and heat were effective at reducing PEDV genomic material (P < 0.05), but did not completely eliminate it.

Standoff detection of explosives: a challenging approach for optical technologies

NASA Astrophysics Data System (ADS)

Désilets, S.; Hô, N.; Mathieu, P.; Simard, J. R.; Puckrin, E.; Thériault, J. M.; Lavoie, H.; Théberge, F.; Babin, F.; Gay, D.; Forest, R.; Maheux, J.; Roy, G.; Châteauneuf, M.

2011-06-01

Standoff detection of explosives residues on surfaces at few meters was made using optical technologies based on Raman scattering, Laser-Induced Breakdown Spectroscopy (LIBS) and passive standoff FTIR radiometry. By comparison, detection and analysis of nanogram samples of different explosives was made with a microscope system where Raman scattering from a micron-size single point illuminated crystal of explosive was observed. Results from standoff detection experiments using a telescope were compared to experiments using a microscope to find out important parameters leading to the detection. While detection and spectral identification of the micron-size explosive particles was possible with a microscope, standoff detection of these particles was very challenging due to undesired light reflected and produced by the background surface or light coming from other contaminants. Results illustrated the challenging approach of detecting at a standoff distance the presence of low amount of micron or submicron explosive particles.

Spatio-temporal evaluation of emerging contaminants and their partitioning along a Brazilian watershed.

PubMed

de Sousa, Diana Nara Ribeiro; Mozeto, Antonio Aparecido; Carneiro, Renato Lajarim; Fadini, Pedro Sergio

2018-02-01

The occurrence, partitioning, and spatio-temporal distribution of seven pharmaceuticals for human use, three steroid hormones and one personal care product were determined in surface water, suspended particulate matter (SPM), and sediment of Piraí Creek and Jundiaí River (Jundiaí River Basin, São Paulo, Brazil). The maximum average detected concentrations of the compounds in the Piraí River samples were < 30 ng L -1 , except for caffeine (222 ng L -1 ). In Jundiaí River samples, most of the compounds were frequently detected, wherein caffeine had the highest concentration, with maximum average concentrations of 14,050 ng L -1 , followed by atenolol (431 ng L -1 ), ibuprofen (268 ng L -1 ) and diclofenac (214 ng L -1 ). Atenolol, propranolol, estrone, and triclosan were the contaminants most frequently detected in sediment and SPM samples. Triclosan had the highest average proportion of SPM as opposed to in the aqueous phase (> 75%). Contaminants with acid functional groups showed, in general, a lower tendency to bind to particulate matter and sediments. In addition, hydrophobicity had an important effect on their environmental partitioning. The spatial distribution of contaminants along the Jundiaí River was mainly affected by the higher concentration of contaminants in water samples collected downstream from a sewage treatment plant (STP). The results obtained here clearly showed the importance of the analysis of some contaminants in the whole water, meaning both dissolved and particulate compartments in the water, and that the partitioning is ruled by a set of parameters associated to the physicochemical characteristics of contaminants and the matrix properties of the studied, which need be considered in an integrated approach to understand the fate of emerging chemical contaminants in aquatic environments.

Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages

PubMed Central

Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K. Johanna

2015-01-01

Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected to culturing and amplicon sequence analyses. Abundant mesophilic psychrotrophs were detected within the microbiomes throughout the different compartments of the production plant environment. However, each of the main genera of food safety and quality interest, e.g., Leuconostoc, Brochothrix, and Yersinia, had their own characteristic patterns of contamination. Bacteria from the genus Leuconostoc, commonly causing spoilage of cold-stored, modified-atmosphere-packaged foods, were detected in high abundance (up to >98%) in the sausages studied. The same operational taxonomic units (OTUs) were, however, detected in lower abundances in raw meat and emulsion (average relative abundance of 2% ± 5%), as well as on the processing plant surfaces (<4%). A completely different abundance profile was found for OTUs phylogenetically close to the species Yersinia pseudotuberculosis. These OTUs were detected in high abundance (up to 28%) on the processing plant surfaces but to a lesser extent (<1%) in raw meat, sausage emulsion, and sausages. The fact that Yersinia-like OTUs were found on the surfaces of a high-hygiene packaging compartment raises food safety concerns related to their resilient existence on surfaces. PMID:26231646

A Simplified Method for Sampling and Analysis of High Volume Surface Water for Organic Contaminants Using XAD-2

USGS Publications Warehouse

Datta, S.; Do, L.V.; Young, T.M.

2004-01-01

A simple compressed-gas driven system for field processing and extracting water for subsequent analyses of hydrophobic organic compounds is presented. The pumping device is a pneumatically driven pump and filtration system that can easily clarify at 4L/min. The extraction device uses compressed gas to drive filtered water through two parallel XAD-2 resin columns, at about 200 mL/min. No batteries or inverters are required for water collection or processing. Solvent extractions were performed directly in the XAD-2 glass columns. Final extracts are cleaned-up on Florisil cartridges without fractionation and contaminants analyzed by GC-MS. Method detection limits (MDLs) and recoveries for dissolved organic contaminants, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides are reported along with results of surface water analysis for the San Francisco Bay, CA.

Public health assessment for petro-processors of Lousiana Incorporated, Baton Rouge, East Baton Rouge Parish, Louisiana, Region 6. Cerclis No. LAD057482713. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-01-16

The Petro-Processors of Louisiana, Inc. (PPI) site, located in East Baton Rouge Parish, Louisiana, operated two waste disposal facilities: the Brooklawn area and the Scenic Highway area. Both areas contain chlorinated aromatic hydrocarbons and chlorinated hydrocarbons. Contaminants have been detected in samples from soil, groundwater, surface water, and air at the Brooklawn area and in soil, groundwater, and air at the Scenic Highway area. The site is considered a public health hazard because of risks to human health from past, present, and future exposure to hazardous substances. Exposure pathways of public health concern are: ingestion of contaminated fish, potential ingestionmore » of contaminated groundwater and wildlife, dermal contact with contaminated sediments, inhalation of airborne volatile contaminants prior to and during remedial activities, and dermal contact and incidental ingestion of contaminated soils.« less

Flight investigation of insect contamination and its alleviation

NASA Technical Reports Server (NTRS)

Peterson, J. B., Jr.; Fisher, D. F.

1978-01-01

An investigation of leading edge contamination by insects was conducted with a JetStar airplane instrumented to detect transition on the outboard leading edge flap and equipped with a system to spray the leading edge in flight. The results of airline type flights with the JetStar indicated that insects can contaminate the leading edge during takeoff and climbout. The results also showed that the insects collected on the leading edges at 180 knots did not erode at cruise conditions for a laminar flow control airplane and caused premature transition of the laminar boundary layer. None of the superslick and hydrophobic surfaces tested showed any significant advantages in alleviating the insect contamination problem. While there may be other solutions to the insect contamination problem, the results of these tests with a spray system showed that a continouous water spray while encountering the insects is effective in preventing insect contamination of the leading edges.

Canine scent detection and microbial source tracking of human waste contamination in storm drains.

PubMed

Van De Werfhorst, Laurie C; Murray, Jill L S; Reynolds, Scott; Reynolds, Karen; Holden, Patricia A

2014-06-01

Human fecal contamination of surface waters and drains is difficult to diagnose. DNA-based and chemical analyses of water samples can be used to specifically quantify human waste contamination, but their expense precludes routine use. We evaluated canine scent tracking, using two dogs trained to respond to the scent of municipal wastewater, as a field approach for surveying human fecal contamination. Fecal indicator bacteria, as well as DNA-based and chemical markers of human waste, were analyzed in waters sampled from canine scent-evaluated sites (urban storm drains and creeks). In the field, the dogs responded positively (70% and 100%) at sites for which sampled waters were then confirmed as contaminated with human waste. When both dogs indicated a negative response, human waste markers were absent. Overall, canine scent tracking appears useful for prioritizing sampling sites for which DNA-based and similarly expensive assays can confirm and quantify human waste contamination.

Materials SIG quantification and characterization of surface contaminants

NASA Technical Reports Server (NTRS)

Crutcher, E. Russ

1992-01-01

When LDEF entered orbit its cleanliness was approximately a MIL-STD-1246B Level 2000C. Its burden of contaminants included particles from every part of its history including a relatively small contribution from the shuttle bay itself. Although this satellite was far from what is normally considered clean in the aerospace industry, contaminating events in orbit and from processing after recovery were easily detected. The molecular contaminants carried into orbit were dwarfed by the heavy deposition of UV polymerized films from outgassing urethane paints and silicone based materials. Impacts by relatively small objects in orbit could create particulate contaminants that easily dominated the particle counts within a centimeter of the impact site. During the recovery activities LDEF was 'sprayed' with a liquid high in organics and water soluble salts. With reentry turbulence, vibration, and gravitational loading particulate contaminants were redistributed about LDEF and the shuttle bay.

Baseline aquatic contamination and endocrine status in a resident fish of Biscayne National Park

USGS Publications Warehouse

Bargar, Timothy A.; Whelan, Kevin R.T.; Alvarez, David; Echols, Kathy R.; Peterman, Paul H.

2017-01-01

Surface water, sediment, and fish from Biscayne Bay, coastal wetlands adjacent to the Bay, and canals discharging into the Bay were sampled for determination of baseline contamination in Biscayne National Park. While the number of contaminants detected in canal waters was greater during the wet season than the dry season, no seasonal difference was evident for Biscayne Bay or coastal wetland waters. Estrogen equivalency (as 17β-estradiol equivalents), as predicted by the Yeast Estrogen Screen, for extracts of passive water samplers deployed in canals and wetlands was elevated during the wet relative to the dry season. Generally, contamination in water, sediments, and fish was greater in the canals than in Biscayne Bay and the wetlands. Guideline levels for sediment contaminant were exceeded most frequently in canals relative to the coastal wetlands and the Bay. Further investigation is necessary to better understand the impact of contaminants in Biscayne National Park.

Exploring the Behaviour of Emerging Contaminants in the Water Cycle using the Capabilities of High Resolution Mass Spectrometry.

PubMed

Hollender, Juliane; Bourgin, Marc; Fenner, Kathrin B; Longrée, Philipp; Mcardell, Christa S; Moschet, Christoph; Ruff, Matthias; Schymanski, Emma L; Singer, Heinz P

2014-11-01

To characterize a broad range of organic contaminants and their transformation products (TPs) as well as their loads, input pathways and fate in the water cycle, the Department of Environmental Chemistry (Uchem) at Eawag applies and develops high-performance liquid chromatography (LC) methods combined with high-resolution tandem mass spectrometry (HRMS/MS). In this article, the background and state-of-the-art of LC-HRMS/MS for detection of i) known targets, ii) suspected compounds like TPs, and iii) unknown emerging compounds are introduced briefly. Examples for each approach are taken from recent research projects conducted within the department. These include the detection of trace organic contaminants and their TPs in wastewater, pesticides and their TPs in surface water, identification of new TPs in laboratory degradation studies and ozonation experiments and finally the screening for unknown compounds in the catchment of the river Rhine.

Diffuse Reflectance Mid-Infrared Spectroscopy as a Tool for the Identification of Surface Contamination on Sandblasted Metals

NASA Technical Reports Server (NTRS)

Powell, Louis G.; Barber, Tye E.; Neu, John T.; Nerren, Billy H.

1997-01-01

The SOC 400 Surface Inspection Machine/Infrared (SIMIR) is a small, ruggedized Fourier transform infrared spectrometer having dedicated diffuse reflectance optics. The SOC 400 was designed for the purpose of detecting (qualitatively and quantitatively) oil stains on the inside surface of solid rocket motor casings in the as-sandblasted and cleaned condition at levels approaching 1 mg. sq ft. The performance of this instrument is described using spectral mapping techniques.

Contamination by Meat Juice When Shopping for Packages of Raw Poultry.

PubMed

Chen, Fur-Chi; Godwin, Sandria; Chambers, Delores; Chambers, Edgar; Cates, Sheryl; Stone, Richard; Donelan, Amy

2018-05-01

Raw poultry products often are contaminated with Salmonella and Campylobacter, and these bacteria can be transmitted through meat juice on the packages. An observational study was conducted to assess consumer exposure to meat juice during shopping and to quantify the transmission of meat juice from poultry packages to hands and other surfaces. Ninety-six participants completed the shopping study; 402 swabs were collected and analyzed for the presence of meat juice by an immunoassay. Overall, meat juice was detected on 61% of poultry package surfaces, 34% of shoppers' hands, 41% of grocery bags, 60% of kitchen surfaces, and 51% of food item surfaces. When meat juice was detected on the purchased poultry packages, the chance of the meat juice being on the shopper's hands, grocery bags, food items, and kitchen surfaces was significantly higher ( P < 0.005) compared with packages on which meat juice was not present. Shoppers who had poultry wrapped separately during checkout had a significantly lower ( P < 0.05) chance of meat juice on the food items. However, using plastic bags and wrapping poultry separately did not significantly reduce the likelihood of meat juice on kitchen surfaces at home due to consumers' practices of repackaging before storage. Results suggested that the transfer of meat juice through direct contact with the poultry packages is a major concern during shopping and should be prevented.

Laser-induced contamination control for high-power lasers in space-based LIDAR missions

NASA Astrophysics Data System (ADS)

Alves, Jorge; Pettazzi, Federico; Tighe, Adrian; Wernham, Denny

2017-11-01

In the framework of the ADM-Aeolus satellite mission, successful test campaigns have been performed in ESTEC's laser laboratory, and the efficiency of several mitigation techniques against Laser-Induced Contamination (LIC) have been demonstrated for the ALADIN laser. These techniques include the standard contamination control methods of materials identification with particular tendency to cause LIC, reduction of the outgassing of organic materials by vacuum bake-out and shielding of optical surfaces from the contamination sources. Also novel mitigation methods such as in-situ cleaning via partial pressures, or the usage of molecular absorbers were demonstrated. In this context, a number of highly sensitive optical measurement techniques have been developed and tested to detect and monitor LIC deposits at nanometre level.

Nano-immunoassay with improved performance for detection of cancer biomarkers

DOE PAGES

Krasnoslobodtsev, Alexey V.; Torres, Maria P.; Kaur, Sukhwinder; ...

2015-01-01

Nano-immunoassay utilizing surface-enhanced Raman scattering (SERS) effect is a promising analytical technique for the early detection of cancer. In its current standing the assay is capable of discriminating samples of healthy individuals from samples of pancreatic cancer patients. Further improvements in sensitivity and reproducibility will extend practical applications of the SERS-based detection platforms to wider range of problems. In this report, we discuss several strategies designed to improve performance of the SERS-based detection system. We demonstrate that reproducibility of the platform is enhanced by using atomically smooth mica surface as a template for preparation of capture surface in SERS sandwichmore » immunoassay. Furthermore, the assay's stability and sensitivity can be further improved by using either polymer or graphene monolayer as a thin protective layer applied on top of the assay addresses. The protective layer renders the signal to be more stable against photo-induced damage and carbonaceous contamination.« less

Hepatitis E Virus in Pork Food Chain, United Kingdom, 2009–2010

PubMed Central

Berto, Alessandra; Martelli, Francesca; Grierson, Sylvia

2012-01-01

We investigated contamination by hepatitis E virus (HEV) in the pork production chain in the United Kingdom. We detected HEV in pig liver samples in a slaughterhouse, in surface samples from a processing plant, and in pork sausages and surface samples at point of sale. Our findings provide evidence for possible foodborne transmission of HEV during pork production. PMID:22840183

[The study of the contamination and the levels of Campylobacter spp. during the processing of selected types of foods].

PubMed

Efimochkina, N R; Bykova, I B; Stetsenko, V V; Minaeva, L P; Pichugina, T V; Markova, Yu M; Korotkevich, Yu V; Kozak, S S; Sheveleva, S A

2016-01-01

The purpose of the work was to study the nature of the Campylobacter spp. contamination during the processing of food products of plant and animal origin (raw poultry and beef meat, raw milk, leafy salads, sliced raw vegetables). In the study of 148 samples 50 strains of Campylobacter spp. (33.8%) were found. For the main phenotypic characteristics they were identified as C. jejuni spp. jejuni and C. jejuni spp. doylei (over 75%). The highest level of detection of campylobacteria (over 45%) was set for raw poultry, including the carcasses of chickens broilers, quails, turkeys and their semi-finished products. 19 of the 27 strains from poultry were identified as C. jejuni. Among the strains isolated from the environment, including swabs from equipment surfaces, 91% of the isolates were also presented by C. jejuni. It was found that the investigated foodstuffs were characterized by high levels of contamination with bacteria of the family Enterobacteriaceae, the content of which was comparable with the identified values of total viable bacteria (cfu). Salmonella was detected in 19% of the investigated poultry samples and in 14.3% of raw cow milk. In the study of swabs from surfaces of poultry processing equipment, the frequency of detection of Campylobacter strains was 38.7%, Salmonella - 12.9%. Most commonly Campylobacter and Salmonella were detected in the zones of primary processing of poultry: the frequency of isolation of Salmonella in slaughter corner was 25%, Campylobacter - 43%. When testing the swabs taken in the cooking zone of «fast food» restaurants Campylobacter and Salmonella were not detected. For studying the swabs from equipment surfaces and the environment for the presence of Campylobacter spp. a modified technique of sampling was developed. The method includes a comprehensive analysis in the test area with the use of three types of media for transportation and incubation of Campylobacter spp. (Preston broth with blood, Brucella broth, Cary-Blair medium), that increase the probability of detection of these pathogens.

MICROCYSTIN ANALYSIS IN HUMAN SERA AND LIVER FROM HUMAN FATALITIES IN CARUARU, BRAZIL 1996

EPA Science Inventory

The detection of cyanotoxins, especially hepatotoxic microcystins in tissue, is of growing interest to scientists, clinicians, and public health officials because cyanotoxins can contaminate surface waters that are used for drinking and recreational purposes. Documentation of hum...

Fungicide and Nutrient Transport with Runoff from Creeping Bentgrass Turf

USDA-ARS?s Scientific Manuscript database

The detection of pesticides and excess nutrients in surface waters of urban watersheds has lead to increased environmental concern and suspect of contaminant contributions from residential, urban, and recreational sources. Highly managed biotic systems such as golf courses and commercial landscapes ...

Aerobic biodegradation potential of endocrine-disrupting chemicals in surface-water sediment at Rocky Mountain National Park, USA.

PubMed

Bradley, Paul M; Battaglin, William A; Iwanowicz, Luke R; Clark, Jimmy M; Journey, Celeste A

2016-05-01

Endocrine-disrupting chemicals (EDCs) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDCs, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountain National Park (Colorado, USA). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 (14) C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. Bed sediment microbial communities in Rocky Mountain National Park also effectively degraded the xenoestrogens bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The present study's results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

Surface contamination analysis technology team overview

NASA Technical Reports Server (NTRS)

Burns, H. Dewitt

1995-01-01

A team was established which consisted of representatives from NASA (Marshall Space Flight Center and Langley Research Center), Thiokol Corporation, the University of Alabama in Huntsville, AC Engineering, SAIC, Martin Marietta, and Aerojet. The team's purpose was to bring together the appropriate personnel to determine what surface inspection techniques were applicable to multiprogram bonding surface cleanliness inspection. In order to identify appropriate techniques and their sensitivity to various contaminant families, calibration standards were developed. Producing standards included development of consistent low level contamination application techniques. Oxidation was also considered for effect on inspection equipment response. Ellipsometry was used for oxidation characterization. Verification testing was then accomplished to show that selected inspection techniques could detect subject contaminants at levels found to be detrimental to critical bond systems of interest. Once feasibility of identified techniques was shown, selected techniques and instrumentation could then be incorporated into a multipurpose inspection head and integrated with a robot for critical surface inspection. Inspection techniques currently being evaluated include optically stimulated electron emission (OSEE); near infrared (NIR) spectroscopy utilizing fiber optics; Fourier transform infrared (FTIR) spectroscopy; and ultraviolet (UV) fluorescence. Current plans are to demonstrate an integrated system in MSFC's Productivity Enhancement Complex within five years from initiation of this effort in 1992 assuming appropriate funding levels are maintained. This paper gives an overview of work accomplished by the team and future plans.

Relationship between viral detection and turbidity in a watershed contaminated with group A rotavirus.

PubMed

Assis, Andrêssa Silvino Ferreira; Cruz, Lucas Taffarel; Ferreira, Aline Siqueira; Bessa, Martha Eunice; de Oliveira Pinto, Miriam Aparecida; Vieira, Carmen Baur; Otenio, Marcelo Henrique; Miagostovich, Marize Pereira; da Rosa E Silva, Maria Luzia

2015-05-01

Enteric viruses are present in aquatic environments due to contamination by raw sewage, even in the absence of fecal coliforms, which are considered to be significant indicators when it comes to microbial water quality assessment. This study investigated the presence of group A rotavirus (RVA) in surface water from a river basin in Minas Gerais, Brazil, assessing the influence of the urbanization, the rainfall, and the microbiological and physico-chemical parameters regarding water quality. Forty-eight surface water samples collected in urbanized and non-urbanized areas, both in dry and rainy periods, were obtained throughout the study. The viral particles were concentrated by adsorption-elution in a negatively charged membrane. Fecal coliforms, as well as physico-chemical water parameters were determined at each point in all collections. The RVA was detected in 62.5 % (30/48) of the water samples through a real-time PCR assay. All the sequenced RVA strains belonged to genotype I1. The RVA was detected in 50.0 % (11/22) of the water samples regarded as being acceptable by current microbiological standards. The presence of the RVA and the viral load were influenced by the collection area (p < 0.05). It was also observed a significant association between the RVA and detecting the turbidity of water (p < 0.05). The collected data showed a high level of contamination in this watershed by the discharge of raw sewage, highlighting the need for urgent measures to improve water quality, ensuring the safe use of this matrix.

Decontamination of clothing and building materials associated with the clandestine production of methamphetamine.

PubMed

Serrano, Kate A; Martyny, John W; Kofford, Shalece; Contreras, John R; Van Dyke, Mike V

2012-01-01

This study was designed to determine how easily methamphetamine can be removed from clothing and building materials, utilizing different cleaning materials and methods. The study also addressed the penetration of methamphetamine into drywall and the ability of paints to encapsulate the methamphetamine on drywall. Clothing and building materials were contaminated in a stainless steel chamber by aerosolizing methamphetamine in a beaker heater. The amount of methamphetamine surface contamination was determined by sampling a grid pattern on the material prior to attempting to clean the materials. After cleaning, the materials were again sampled, and the degree of decontamination noted. We found that household clothing and response gear worn by first responders was easily decontaminated using a household detergent in a household washing machine. A single wash removed over 95% of the methamphetamine from these materials. The study also indicated that methamphetamine-contaminated, smooth non-porous surfaces can be easily cleaned to below detectable levels using only mild cleaners. More porous surfaces such as plywood and drywall were unlikely to be decontaminated to below regulatory levels even with three washes using a mild cleaner. This may be due to methamphetamine penetration into the paint on these surfaces. Evaluation of methamphetamine contamination on drywall indicated that approximately 40% of the methamphetamine was removed using a wipe, while another 60% remained in the paint layer. Stronger cleaners such as those with active ingredients including sodium hypochlorite or quaternary ammonia and commercial decontamination agents were more effective than mild detergent-based cleaners and may reduce methamphetamine contamination to below regulatory levels. Results from the encapsulation studies indicate that sprayed on oil-based paint will encapsulate methamphetamine on drywall and plywood surfaces up to 4.5 months, while latex paints were less effective.

Comparison of Two Surface Contamination Sampling Techniques Conducted for the Characterization of Two Pajarito Site Manhattan Project National Historic Park Properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, Tammy Ann

Technical Area-18 (TA-18), also known as Pajarito Site, is located on Los Alamos National Laboratory property and has historic buildings that will be included in the Manhattan Project National Historic Park. Characterization studies of metal contamination were needed in two of the four buildings that are on the historic registry in this area, a “battleship” bunker building (TA-18-0002) and the Pond cabin (TA-18-0029). However, these two buildings have been exposed to the elements, are decades old, and have porous and rough surfaces (wood and concrete). Due to these conditions, it was questioned whether standard wipe sampling would be adequate tomore » detect surface dust metal contamination in these buildings. Thus, micro-vacuum and surface wet wipe sampling techniques were performed side-by-side at both buildings and results were compared statistically. A two-tail paired t-test revealed that the micro-vacuum and wet wipe techniques were statistically different for both buildings. Further mathematical analysis revealed that the wet wipe technique picked up more metals from the surface than the microvacuum technique. Wet wipes revealed concentrations of beryllium and lead above internal housekeeping limits; however, using an yttrium normalization method with linear regression analysis between beryllium and yttrium revealed a correlation indicating that the beryllium levels were likely due to background and not operational contamination. PPE and administrative controls were implemented for National Park Service (NPS) and Department of Energy (DOE) tours as a result of this study. Overall, this study indicates that the micro-vacuum technique may not be an efficient technique to sample for metal dust contamination.« less

Method of making gold thiolate and photochemically functionalized microcantilevers

DOEpatents

Boiadjiev, Vassil I [Knoxville, TN; Brown, Gilbert M [Knoxville, TN; Pinnaduwage, Lal A [Knoxville, TN; Thundat, Thomas G [Knoxville, TN; Bonnesen, Peter V [Knoxville, TN; Goretzki, Gudrun [Nottingham, GB

2009-08-25

Highly sensitive sensor platforms for the detection of specific reagents, such as chromate, gasoline and biological species, using microcantilevers and other microelectromechanical systems (MEMS) whose surfaces have been modified with photochemically attached organic monolayers, such as self-assembled monolayers (SAM), or gold-thiol surface linkage are taught. The microcantilever sensors use photochemical hydrosilylation to modify silicon surfaces and gold-thiol chemistry to modify metallic surfaces thereby enabling individual microcantilevers in multicantilever array chips to be modified separately. Terminal vinyl substituted hydrocarbons with a variety of molecular recognition sites can be attached to the surface of silicon via the photochemical hydrosilylation process. By focusing the activating UV light sequentially on selected silicon or silicon nitride hydrogen terminated surfaces and soaking or spotting selected metallic surfaces with organic thiols, sulfides, or disulfides, the microcantilevers are functionalized. The device and photochemical method are intended to be integrated into systems for detecting specific agents including chromate groundwater contamination, gasoline, and biological species.

Imposex and butyltin contamination still evident in Chile after TBT global ban.

PubMed

Batista, Rodrigo Moço; Castro, Italo Braga; Fillmann, Gilberto

2016-10-01

Imposex in gastropods (Acanthina monodon, Oliva peruviana and Xanthochorus cassidiformis), butyltin levels in surface sediments (Coquimbo and Concepcion) and tissues (Valparaiso and Concepcion) were assessed in three areas under the influence of maritime activities along the central Chilean coast. The highest TBT concentrations were observed in São Vicente Bay (Concepcion), reaching 122.3ngSng(-1) in surface sediments and 59.7ngSng(-1) in gastropods tissue, while in Valparaiso ranged from 7.4 to 15.8ngSng(-1) in biota. The lowest TBT concentrations were detected in sediments from Coquimbo (<2ngSng(-1)), which can be attributed to a much lower ship/boat traffic (probably using TBT free products) in association to local oceanographic conditions. Despite DBT and MBT were the predominant analytes, recent inputs of TBT were evident in some areas. In fact, fishing boats may be a relevant source since they were the predominant maritime activity in the most contaminated sites. In addition, the absence of significant differences within BTs levels between both genders of A. monodon suggests that tissues from distinct sexes can be indistinctly used for future contamination studies. Imposex incidence was detected in 11 out of 15 sampled sites, indicating that environmental levels of TBT have been sufficient to induce deleterious effects on the exposed organisms. Thus, the impacts caused by TBT in Chilean coastal areas were detectable and consistent with other studies performed in South America. This present environmental contamination is probably due to the lack of regulations forbidding the use of TBT-based antifouling paints in Chile. Copyright © 2016 Elsevier B.V. All rights reserved.

Standoff laser-based spectroscopy for explosives detection

NASA Astrophysics Data System (ADS)

Gaft, M.; Nagli, L.

2007-10-01

Real time detection and identification of explosives at a standoff distance is a major issue in efforts to develop defense against so-called Improvised Explosive Devices (IED). It is recognized that the only technique, which is potentially capable to standoff detection of minimal amounts of explosives is laser-based spectroscopy. LDS activity is based on a combination of laser-based spectroscopic methods with orthogonal capabilities. Our technique belongs to trace detection, namely to its micro-particles variety. It is based on commonly held belief that surface contamination was very difficult to avoid and could be exploited for standoff detection. We has applied optical techniques including gated Raman and time-resolved luminescence spectroscopy for detection of main explosive materials, both factory and homemade. We developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 meters.

Modeling Cryptosporidium and Giardia in Ground and Surface Water Sources in Rural India: Associations with Latrines, Livestock, Damaged Wells, and Rainfall Patterns.

PubMed

Daniels, Miles E; Smith, Woutrina A; Schmidt, Wolf-Peter; Clasen, Thomas; Jenkins, Marion W

2016-07-19

Surface and groundwater contamination with fecal pathogens is a public health concern especially in low-income settings where these sources are used untreated. We modeled observed Cryptosporidium and Giardia contamination in community ponds (n = 94; 79% contaminated), deep tubewells (DTWs) (n = 107; 17%), and shallow tubewells (STWs) (n = 96; 19%) during the 2012 and 2013 monsoon seasons (June-August) in 60 villages in Puri District, India to understand sources and processes of contamination. Detection of Cryptosporidium and/or Giardia in a tubewell was positively associated with damage to the well pad for DTWs, the amount of human loading into pour-flush latrine pits nearby (≤15 m) for STWs, and the village literacy rate (for Giardia in STWs). Pond concentration levels were positively associated with the number of people practicing open defecation within 50 m and the sheep population for Cryptosporidium, and with the village illiteracy rate for Giardia. Recent rainfall increased the risk of Cryptosporidium in STWs (an extreme event) and ponds (any), while increasing seasonal rainfall decreased the risk of Giardia in STWs and ponds. Full latrine coverage in this setting is expected to marginally reduce pond Cryptosporidium contamination (16%) while increasing local groundwater protozoal contamination (87-306%), with the largest increases predicted for Cryptosporidium in STWs.

Runoff of pyrethroid insecticides from concrete surfaces following simulated and natural rainfalls.

PubMed

Jiang, Weiying; Haver, Darren; Rust, Michael; Gan, Jay

2012-03-01

Intensive residential use of insecticides has resulted in their ubiquitous presence as contaminants in urban surface streams. For pest eradication, urban hard surfaces such as concrete are often directly treated with pesticides, and wind/water can also carry pesticides onto hard surfaces from surrounding areas. This study expanded on previous bench-scale studies by considering pesticide runoff caused by irrigation under dry weather conditions and rain during the wet season, and evaluated the effects of pesticide residence time on concrete, single versus recurring precipitations, precipitation intensity, and concrete surface conditions, on pesticide transferability to runoff water. Runoff from concrete 1 d after pesticide treatment contained high levels of bifenthrin (82 μg/L) and permethrin (5143 μg/L for cis and 5518 μg/L for trans), indicating the importance of preventing water contact on concrete after pesticide treatments. Although the runoff transferability quickly decreased as the pesticide residence time on concrete increased, detectable residues were still found in runoff water after 3 months (89 d) exposure to hot and dry summer conditions. ANOVA analysis showed that precipitation intensities and concrete surface conditions (i.e., acid wash, silicone seal, stamping, and addition of microsilica) did not significantly affect the pesticide transferability to runoff. For concrete slabs subjected to natural rainfalls during the winter wet season, pesticide levels in the runoff decreased as the time interval between pesticide application and the rain event increased. However, bifenthrin and permethrin were still detected at 0.15-0.17 and 0.75-1.15 μg/L in the rain runoff after 7 months (221 d) from the initial treatment. In addition, pesticide concentrations showed no decrease between the two rainfall events, suggesting that concrete surfaces contaminated by pesticides may act as a reservoir for pesticide residues, leading to sustained urban runoff contamination. Copyright © 2011 Elsevier Ltd. All rights reserved.

Microbial contamination of vegetable crop and soil profile in arid regions under controlled application of domestic wastewater

PubMed Central

Balkhair, Khaled S.

2015-01-01

Increasing lack of potable water in arid countries leads to the use of treated wastewater for crop production. However, the use of inappropriate irrigation practices could result in a serious contamination risk to plants, soils, and groundwater with sewage water. This research was initiated in view to the increasing danger of vegetable crops and groundwater contamination with pathogenic bacteria due to wastewater land application. The research was designed to study: (1) the effect of treated wastewater irrigation on the yield and microbial contamination of the radish plant under field conditions; (2) contamination of the agricultural soil profile with fecal coliform bacteria. Effluent from a domestic wastewater treatment plant (100%) in Jeddah city, Saudi Arabia, was diluted to 80% and 40% with the groundwater of the experimental site constituting three different water qualities plus groundwater as control. Radish plant was grown in two consecutive seasons under two drip irrigation systems and four irrigation water qualities. Upon harvesting, plant weight per ha, total bacterial, fecal coliform, fecal streptococci were detected per 100 g of dry matter and compared with the control. The soil profile was also sampled at an equal distance of 3 cm from soil surface for fecal coliform detection. The results indicated that the yield increased significantly under the subsurface irrigation system and the control water quality compared to surface irrigation system and other water qualities. There was a considerable drop in the count of all bacteria species under the subsurface irrigation system compared to surface irrigation. The bacterial count/g of the plant shoot system increased as the percentage of wastewater in the irrigation water increased. Most of the fecal coliform bacteria were deposited in the first few centimeters below the column inlet and the profile exponentially decreased with increasing depth. PMID:26858571

Pharmaceuticals, hormones, pesticides, and other bioactive contaminants in water, sediment, and tissue from Rocky Mountain National Park, 2012–2013

USGS Publications Warehouse

Battaglin, William A.; Bradley, Paul M.; Iwanowicz, Luke R.; Journey, Celeste A.; Walsh, Heather L.; Blazer, Vicki S.

2018-01-01

Pharmaceuticals, hormones, pesticides, and other bioactive contaminants (BCs) are commonly detected in surface water and bed sediment in urban and suburban areas, but these contaminants are understudied in remote locations. In Rocky Mountain National Park (RMNP), Colorado, USA, BCs may threaten the reproductive success and survival of native aquatic species, benthic communities, and pelagic food webs. In 2012–2013, 67 water, 57 sediment, 63 fish, 10 frog, and 12 quality-control samples (8 water and 4 sediment) were collected from 20 sites in RMNP. Samples were analyzed for 369 parameters including 149 pharmaceuticals, 22 hormones, 137 pesticides, and 61 other chemicals or conditions to provide a representative assessment of BC occurrence within RMNP. Results indicate that BCs were detected in water and/or sediment from both remote and more accessible locations in RMNP. The most commonly detected BCs in water were caffeine, camphor, para-cresol, and DEET; and the most commonly detected BCs in sediment were indole, 3-methyl-1H-indole, para-cresol, and 2,6-dimethyl-naphthalene. Some detected contaminants, including carbaryl, caffeine, and oxycodone, are clearly attributable to direct local human input, whereas others may be transported into the park atmospherically (e.g., atrazine) or have local natural sources (e.g., para-cresol). One or more pharmaceuticals were detected in at least 1 sample from 15 of 20 sites. Most of the 29 detected pharmaceuticals are excreted primarily in human urine, not feces. Elevated net estrogenicity was observed in 18% of water samples, and elevated vitellogenin in blood was observed in 12% of male trout, both evidence of potential endocrine disruption. Hormone concentrations in sediment tended to be greater than concentrations in water. Most BCs were observed at concentrations below those not expected to pose adverse effects to aquatic life. Results indicate that even in remote locations aquatic wildlife can be exposed to pharmaceuticals, hormones, pesticides, and other bioactive contaminants.

Ground-Water Levels and Water-Quality Data for Wells in the Crumpton Creek Area near Arnold Air Force Base, Tennessee, November 2001 to January 2002

USGS Publications Warehouse

Williams, Shannon D.

2003-01-01

From November 2001 to January 2002, a study of the ground-water resources in the Crumpton Creek area of Middle Tennessee was conducted to determine whether volatile organic compounds (VOCs) from Arnold Air Force Base (AAFB) have affected local private water supplies and to advance understanding of the ground-water-flow system in this area. VOC samples were collected from private wells that were not included in previous sampling efforts conducted in the Crumpton Creek area near AAFB. Ground-water-flow directions were investigated by measuring water levels in wells and constructing a potentiometric-surface map of the Manchester aquifer in the study area. Data were collected from a total of 68 private wells, 82 monitoring wells, and 1 cave during the period of study. Ground-water levels were determined for 42 of the private wells and for all 82 monitoring wells. Of the 82 monitoring wells, 81 withdraw water from the Manchester aquifer and 1 well withdraws water from the overlying shallow aquifer. The Manchester aquifer wells range in depth from 20 to 150 feet. Water-level altitudes for the Manchester aquifer ranged from 956 to 1,064 feet above the National Geodetic Vertical Datum of 1929. Water levels ranged from approximately 6 feet above land surface to 94 feet below land surface. Water-quality samples were collected from all 68 private wells, 8 of the monitoring wells, and the 1 cave. Of the 55 VOCs analyzed, 42 were not detected. Thirteen VOCs were detected; however, only tetrachloroethylene (PCE), methylene chloride, and toluene were detected at concentrations equal to or above reporting levels for the analytical method used. PCE was detected in water samples from 15 private wells and was the only VOC that exceeded drinking water maximum contaminant levels for public water systems. PCE concentrations in samples from five of the wells were below the reporting level and ranged from estimated concentrations of 0.46 to 0.80 microgram per liter (?g/L). Samples from 10 wells contained concentrations equal to or greater than the analytical reporting level of 1 ?g/L for PCE. Samples from one of these wells contained PCE concentrations (12 ?g/L and 11 ?g/L) exceeding the drinking water maximum contaminant level of 5 ?g/L for PCE. The spatial distribution of PCE detections and the relative concentrations of PCE and trichloroethylene suggest that the PCE detections are associated with a small and localized ground-water contamination plume unrelated to AAFB ground-water contamination.

Surface inspection using FTIR spectroscopy

NASA Technical Reports Server (NTRS)

Powell, G. L.; Smyrl, N. R.; Williams, D. M.; Meyers, H. M., III; Barber, T. E.; Marrero-Rivera, M.

1995-01-01

The use of reflectance Fourier transform infrared (FTIR) spectroscopy as a tool for surface inspection is described. Laboratory instruments and portable instruments can support remote sensing probes that can map chemical contaminants on surfaces with detection limits under the best of conditions in the sub-nanometer range, i.e.. near absolute cleanliness, excellent performance in the sub-micrometer range, and useful performance for films tens of microns thick. Examples of discovering and quantifying contamination such as mineral oils and greases, vegetable oils, and silicone oils on aluminum foil, galvanized sheet steel, smooth aluminum tubing, and sandblasted 7075 aluminum alloy and D6AC steel. The ability to map in time and space the distribution of oil stains on metals is demonstrated. Techniques associated with quantitatively applying oils to metals, subsequently verifying the application, and non-linear relationships between reflectance and the quantity oil are described.

Nuts and Grains: Microbiology and Preharvest Contamination Risks.

PubMed

Brar, Pardeepinder K; Danyluk, Michelle D

2018-04-01

Low-water-activity foods have been involved in recalls and foodborne disease outbreaks. Increased consumption; better detection methods and reporting systems; improved surveillance, trace-back, and ability to connect sporadic foodborne illnesses; and inadequate implementation of food safety programs are some of the likely reasons for the increase in frequency of recalls and outbreaks linked to dry foods. Nuts and grains can be contaminated with foodborne pathogens at any stage during production, processing, storage, and distribution. Focusing on preharvest contamination, the various potential sources of contamination include soil, animal intrusion, contaminated harvesting equipment, harvest and preharvest handling, storage conditions, and others. The low water activity of nuts and grains prevents the growth of most foodborne pathogens on their surfaces. The long-term survival of bacterial foodborne pathogens ( Salmonella , Escherichia coli O157:H7, and Listeria monocytogenes ) on dry foods has been documented in the literature for different nut types. Preventing contamination is the key to avoiding foodborne disease risks linked to dry foods. The implementation of good agricultural practices and other food safety systems provides a proactive approach to address concerns thoroughly. A plethora of research is available on preventing the growth of mycotoxin-producing fungi on the surface of nuts and grains. Milling is an effective mechanism to reduce the microbial load on grains. This review focuses on providing information about associated foodborne microorganisms, preharvest contamination sources, and good agricultural practice recommendations for nuts and grains.

Screening and characterization of Staphylococcus aureus from ophthalmology clinic surfaces: a proposed surveillance tool

PubMed Central

Reem, Rachel E.; Van Balen, Joany; Hoet, Armando E.; Cebulla, Colleen M.

2014-01-01

Purpose To screen environmental surfaces of an outpatient ophthalmic clinic for methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA); to identify the most commonly contaminated surfaces; and to phenotype and genotype all collected isolates Design A single institution, one-year prospective environmental study Methods Commonly touched surfaces from examination rooms and common areas were targeted and sampled on a quarterly basis for one year. Samples were collected using electrostatic cloths and swabs. S. aureus was isolated using non-selective and selective media. Morphological characteristics and standard biological testing were used to confirm staphylococcal species. S. aureus isolates were phenotypically (Kirby-Bauer method) and genotypically characterized (mecA confirmation, SCCmec typing and pulsed-field gel electrophoresis). Dendrogram analysis was used to establish genetic relatedness between the isolates. Results Of 112 total samples, 27 (24%) and 5 (4%) were MSSA- and MRSA-positive, respectively. Both community-associated (SCCmec IV, USA300) and hospital-associated (SCCmec II, USA100) MRSA isolates were found. No single surface remained consistently positive with the same isolate over time and molecular analysis demonstrated high levels of diversity among isolates. Doorknobs, slit-lamp head/chinrests, and computer keyboards were frequently contaminated. Conclusions The proposed surveillance protocol successfully allowed the detection of both MSSA and MRSA contaminating important high-touch surfaces in a representative ophthalmology clinic. Frequently contaminated surfaces must be targeted for routine cleaning and disinfection as a there is a constant introduction of clones over time. Hence, other clinics may consider implementing and adapting surveillance tools, as the one here described, to help them control these important nosocomial pathogens. PMID:24412125

Hazardous drug residue on exterior vial surfaces: evaluation of a commercial manufacturing process.

PubMed

Power, Luci A; Sessink, Paul J M; Gesy, Kathy; Charbonneau, Flay

2014-04-01

Hazardous drug residue on the exterior surface of drug vials poses a potential risk for exposure of health care workers involved in handling these products. The purpose of this article is to heighten the awareness of this serious issue and to evaluate a commercial manufacturing process for removing and containing hazardous drug (HD) residue on exterior vial surfaces. Additionally, findings from this study are interpreted, incorporated into the current body of evidence, and discussed by experts in this field. This study includes separate evaluations for the presence or absence of surface drug contamination on the vials of 3 HD products: 5-fluorouracil, cisplatin, and methotrexate. The drug products were packaged in vials using a patented prewashing/decontamination method, application of a polyvinylchloride (PVC) base, and use of clear glass vials. An additional step of encasing the vial in a shrink-wrapped sheath was used for 5-fluorouracil and cisplatin. Of all 5-fluorouracil (110 vials), methotrexate (60 vials), and cisplatin (60 vials) tested, only 2 had detectable amounts of surface residue. One 5-fluorouracil vial was found to have approximately 4 mg of 5-fluorouracil on the surface of the vial. The second contaminated vial was cisplatin, which was discovered to have 131 ng of platinum, equal to 200 ng of cisplatin or 0.2 μL of cisplatin solution, on the vial sheath. Using validated extraction and analytic methods, all but 2 of the 230 tested vials were found to be free of surface drug contamination. Pharmacy leaders need to take an active role in promoting the need for clean HD vials. Manufacturers should be required to provide their clients with data derived from externally validated analytic studies, reporting the level of HD contamination on the exterior of their vial products.

Developing monitoring plans to detect spills related to natural gas production.

PubMed

Harris, Aubrey E; Hopkinson, Leslie; Soeder, Daniel J

2016-11-01

Surface water is at risk from Marcellus Shale operations because of chemical storage on drill pads during hydraulic fracturing operations, and the return of water high in total dissolved solids (up to 345 g/L) from shale gas production. This research evaluated how two commercial, off-the-shelf water quality sensors responded to simulated surface water pollution events associated with Marcellus Shale development. First, peak concentrations of contaminants from typical spill events in monitored watersheds were estimated using regression techniques. Laboratory measurements were then conducted to determine how standard in-stream instrumentation that monitor conductivity, pH, temperature, and dissolved oxygen responded to three potential spill materials: ethylene glycol (corrosion inhibitor), drilling mud, and produced water. Solutions ranging from 0 to 50 ppm of each spill material were assessed. Over this range, the specific conductivity increased on average by 19.9, 27.9, and 70 μS/cm for drilling mud, ethylene glycol, and produced water, respectively. On average, minor changes in pH (0.5-0.8) and dissolved oxygen (0.13-0.23 ppm) were observed. While continuous monitoring may be part of the strategy for detecting spills to surface water, these minor impacts to water quality highlight the difficulty in detecting spill events. When practical, sensors should be placed at the mouths of small watersheds where drilling activities or spill risks are present, as contaminant travel distance strongly affects concentrations in surface water systems.

Application of adverse outcome pathway-based tools to ambient water quality criteria development

EPA Science Inventory

Increasing numbers and diversity of chemical contaminants are being detected in ambient surface waters. States, regions, and communities across the US are faced with the issue of understanding which chemicals may warrant concern and at what concentrations. Integrating new scienti...

Neonicotinoid-contaminated pollinator strips adjacent to cropland reduce honey bee nutritional status

USDA-ARS?s Scientific Manuscript database

Worldwide pollinator declines are attributed to a number of factors, including pesticide exposures. Neonicotinoid insecticides specifically have been detected in surface waters, non-target vegetation, and bee products, but the risks posed by environmental exposures are still not well understood. Pol...

Evaluating the mobility of polymer-stabilised zero-valent iron nanoparticles and their potential to co-transport contaminants in intact soil cores.

PubMed

Chekli, L; Brunetti, G; Marzouk, E R; Maoz-Shen, A; Smith, E; Naidu, R; Shon, H K; Lombi, E; Donner, E

2016-09-01

The use of zero-valent iron nanoparticles (nZVI) has been advocated for the remediation of both soils and groundwater. A key parameter affecting nZVI remediation efficacy is the mobility of the particles as this influences the reaction zone where remediation can occur. However, by engineering nZVI particles with increased stability and mobility we may also inadvertently facilitate nZVI-mediated contaminant transport away from the zone of treatment. Previous nZVI mobility studies have often been limited to model systems as the presence of background Fe makes detection and tracking of nZVI in real systems difficult. We overcame this problem by synthesising Fe-59 radiolabelled nZVI. This enabled us to detect and quantify the leaching of nZVI-derived Fe-59 in intact soil cores, including a soil contaminated by Chromated-Copper-Arsenate. Mobility of a commercially available nZVI was also tested. The results showed limited mobility of both nanomaterials; <1% of the injected mass was eluted from the columns and most of the radiolabelled nZVI remained in the surface soil layers (the primary treatment zone in this contaminated soil). Nevertheless, the observed breakthrough of contaminants and nZVI occurred simultaneously, indicating that although the quantity transported was low in this case, nZVI does have the potential to co-transport contaminants. These results show that direct injection of nZVI into the surface layers of contaminated soils may be a viable remediation option for soils such as this one, in which the mobility of nZVI below the injection/remediation zone was very limited. This Fe-59 experimental approach can be further extended to test nZVI transport in a wider range of contaminated soil types and textures and using different application methods and rates. The resulting database could then be used to develop and validate modelling of nZVI-facilitated contaminant transport on an individual soil basis suitable for site specific risk assessment prior to nZVI remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Personal and household hygiene, environmental contamination, and health in undergraduate residence halls in New York City, 2011.

PubMed

Miko, Benjamin A; Cohen, Bevin; Haxall, Katharine; Conway, Laurie; Kelly, Nicole; Stare, Dianne; Tropiano, Christina; Gilman, Allan; Seward, Samuel L; Larson, Elaine

2013-01-01

While several studies have documented the importance of hand washing in the university setting, the added role of environmental hygiene remains poorly understood. The purpose of this study was to characterize the personal and environmental hygiene habits of college students, define the determinants of hygiene in this population, and assess the relationship between reported hygiene behaviors, environmental contamination, and health status. 501 undergraduate students completed a previously validated survey assessing baseline demographics, hygiene habits, determinants of hygiene, and health status. Sixty survey respondents had microbiological samples taken from eight standardized surfaces in their dormitory environment. Bacterial contamination was assessed using standard quantitative bacterial culture techniques. Additional culturing for coagulase-positive Staphylococcus and coliforms was performed using selective agar. While the vast majority of study participants (n = 461, 92%) believed that hand washing was important for infection prevention, there was a large amount of variation in reported personal hygiene practices. More women than men reported consistent hand washing before preparing food (p = .002) and after using the toilet (p = .001). Environmental hygiene showed similar variability although 73.3% (n = 367) of subjects reported dormitory cleaning at least once per month. Contamination of certain surfaces was common, with at least one third of all bookshelves, desks, refrigerator handles, toilet handles, and bathroom door handles positive for >10 CFU of bacteria per 4 cm(2) area. Coagulase-positive Staphylococcus was detected in three participants' rooms (5%) and coliforms were present in six students' rooms (10%). Surface contamination with any bacteria did not vary by frequency of cleaning or frequency of illness (p>.05). Our results suggest that surface contamination, while prevalent, is unrelated to reported hygiene or health in the university setting. Further research into environmental reservoirs of infectious diseases may delineate whether surface decontamination is an effective target of hygiene interventions in this population.

Personal and Household Hygiene, Environmental Contamination, and Health in Undergraduate Residence Halls in New York City, 2011

PubMed Central

Haxall, Katharine; Conway, Laurie; Kelly, Nicole; Stare, Dianne; Tropiano, Christina; Gilman, Allan; Seward, Samuel L.; Larson, Elaine

2013-01-01

Background While several studies have documented the importance of hand washing in the university setting, the added role of environmental hygiene remains poorly understood. The purpose of this study was to characterize the personal and environmental hygiene habits of college students, define the determinants of hygiene in this population, and assess the relationship between reported hygiene behaviors, environmental contamination, and health status. Methods 501 undergraduate students completed a previously validated survey assessing baseline demographics, hygiene habits, determinants of hygiene, and health status. Sixty survey respondents had microbiological samples taken from eight standardized surfaces in their dormitory environment. Bacterial contamination was assessed using standard quantitative bacterial culture techniques. Additional culturing for coagulase-positive Staphylococcus and coliforms was performed using selective agar. Results While the vast majority of study participants (n = 461, 92%) believed that hand washing was important for infection prevention, there was a large amount of variation in reported personal hygiene practices. More women than men reported consistent hand washing before preparing food (p = .002) and after using the toilet (p = .001). Environmental hygiene showed similar variability although 73.3% (n = 367) of subjects reported dormitory cleaning at least once per month. Contamination of certain surfaces was common, with at least one third of all bookshelves, desks, refrigerator handles, toilet handles, and bathroom door handles positive for >10 CFU of bacteria per 4 cm2 area. Coagulase-positive Staphylococcus was detected in three participants' rooms (5%) and coliforms were present in six students' rooms (10%). Surface contamination with any bacteria did not vary by frequency of cleaning or frequency of illness (p>.05). Conclusions Our results suggest that surface contamination, while prevalent, is unrelated to reported hygiene or health in the university setting. Further research into environmental reservoirs of infectious diseases may delineate whether surface decontamination is an effective target of hygiene interventions in this population. PMID:24312303

The development of a line-scan imaging algorithm for the detection of fecal contamination on leafy geens

NASA Astrophysics Data System (ADS)

Yang, Chun-Chieh; Kim, Moon S.; Chuang, Yung-Kun; Lee, Hoyoung

2013-05-01

This paper reports the development of a multispectral algorithm, using the line-scan hyperspectral imaging system, to detect fecal contamination on leafy greens. Fresh bovine feces were applied to the surfaces of washed loose baby spinach leaves. A hyperspectral line-scan imaging system was used to acquire hyperspectral fluorescence images of the contaminated leaves. Hyperspectral image analysis resulted in the selection of the 666 nm and 688 nm wavebands for a multispectral algorithm to rapidly detect feces on leafy greens, by use of the ratio of fluorescence intensities measured at those two wavebands (666 nm over 688 nm). The algorithm successfully distinguished most of the lowly diluted fecal spots (0.05 g feces/ml water and 0.025 g feces/ml water) and some of the highly diluted spots (0.0125 g feces/ml water and 0.00625 g feces/ml water) from the clean spinach leaves. The results showed the potential of the multispectral algorithm with line-scan imaging system for application to automated food processing lines for food safety inspection of leafy green vegetables.

Landsat change detection can aid in water quality monitoring

NASA Technical Reports Server (NTRS)

Macdonald, H. C.; Steele, K. F.; Waite, W. P.; Shinn, M. R.

1977-01-01

Comparison between Landsat-1 and -2 imagery of Arkansas provided evidence of significant land use changes during the 1972-75 time period. Analysis of Arkansas historical water quality information has shown conclusively that whereas point source pollution generally can be detected by use of water quality data collected by state and federal agencies, sampling methodologies for nonpoint source contamination attributable to surface runoff are totally inadequate. The expensive undertaking of monitoring all nonpoint sources for numerous watersheds can be lessened by implementing Landsat change detection analyses.

Monitoring priority substances, other organic contaminants and heavy metals in a volcanic aquifer from different sources and hydrological processes.

PubMed

Estevez, Esmeralda; Cabrera, María del Carmen; Fernández-Vera, Juan Ramón; Molina-Díaz, Antonio; Robles-Molina, José; Palacios-Díaz, María del Pino

2016-05-01

Irrigation with reclaimed water (R) is necessary to guarantee the sustainability of semi-arid areas. Results obtained during a two years monitoring network (2009-2011) in Gran Canaria are presented, including the analysis of chemical parameters, N and S isotopes, priority substances (2008/105/EC, 2013/39/EU), other organic contaminants and heavy metals in groundwater and R used to irrigate a golf course. The aims of this work are to evaluate the contamination in a volcanic aquifer, relate the presence of organic contaminants and heavy metals with the hydrogeochemistry and identify pollution sources in the area. No priority substance exceeded the EU thresholds for surface water, although seventeen were detected in R. The most frequent compounds were hexachlorobenzene, chlorpyrifos ethyl, fluorene, phenanthrene and pyrene. These compounds were detected at low concentration, except chlorpyrifos. Chlorpyrifos ethyl, terbuthylazine, diuron, terbutryn, procymidone, atrazine and propazine exceeded the European threshold concentration for pesticides in groundwater (100ngL(-1)). Therefore, the priority substances chlorpyrifos ethyl and diuron must be included in monitoring studies. The priority pesticides chlorfenvinphos and diazinon were always detected in R but rarely in groundwater. Besides, the existence of contaminants not related to the current R irrigation has been identified. Absence of environmental problems related to heavy metals can be expected. The relationship among contaminant presence, hydrogeochemistry, including the stable isotopic prints of δ(18)O, δ(15)N and δ(34)S and preferential recharge paths has been described. The coastal well shows high values of EC, nitrate, a variable chemistry, and 50% of organic contaminants detected above 100ngL(-1). The well located in the recharge area presents a stable hydrochemistry, the lowest value of δ(15)N and the lowest contaminants occurrence. The area is an example of a complex volcanic media with several sources of contaminants such as leakages from septic tanks and sewerage, agriculture practices, irrigation with reclaimed water or urban runoff. Copyright © 2016 Elsevier B.V. All rights reserved.

Health assessment for Texarkana Wood Preserving Company, Texarkana, Bowie County, Texas, Region 6. CERCLIS No. TXD008056152. Addendum. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Texarkana Wood Preserving Company (TWPC) is a National Priorities List site located in northeastern Texas, at the southern extremity of the City of Texarkana in Bowie County. The TWPC site has been used for various lumber-related activities since the early 1900s and for creosoting operations since the early 1950s. Contaminated soils, groundwater, surface water, and surface water sediments have been detected on and off of the TWPC site. The primary contaminants of concern are polycyclic aromatic hydrocarbons, pentachlorophenol, chlorinated dibenzodioxins and chlorinated dibenzofurans. The population at greatest risk of exposure to these contaminants are on-site workers engaged in remedialmore » activities. There are currently no residences or businesses located immediately adjacent to the site and no documentation that contaminated groundwater is being used for potable purposes. The Texarkana Wood Preserving Company site has been evaluated by the Agency for Toxic Substances and Disease Registry (ATSDR) Health Activities Recommendation Panel (HARP) for appropriate follow-up with respect to health activities.« less

Dimerization Products of Chloroprene are Background Contaminants Emitted from ALTEF (Polyvinylidene Difluoride) Gas Sampling Bags.

PubMed

Kwak, Jae; Fan, Maomian; Martin, Jennifer A; Ott, Darrin K; Grigsby, Claude C

2017-01-01

Gas sampling bags have been used for collecting air samples. Tedlar bags are most commonly used, but bleed background chemicals such as N,N-dimethylacetamide and phenol. It is often necessary to remove the contaminant by flushing the bags with pure nitrogen or air. In this study, we identified four chloroprene dimerization products as background contaminants emitted from ALTEF bags that are made of a proprietary polyvinylidene difluoride (PVDF). No monomer chloroprene was detected in the bags analyzed. All of the dimers gradually increased once bags were filled with nitrogen due to diffusion from the bag surface. Flushing the bags with nitrogen reduced their concentrations, but was not effective for removing the contaminants. When the bags that had been flushed with nitrogen 5 times were left for 24 h, they increased again, indicating that the dimers were constantly emitted from the ALTEF bag surface. To our knowledge, these compounds have never been demonstrated in ALTEF or other PVDF bags. Our finding indicates that ALTEF might be incorporated with Neoprene (chloroprene-based polymer) during its manufacturing process.

FALLOUT DOSAGE AND MONITORING

PubMed Central

Kinsman, Simon

1960-01-01

At present there are a large number of people capable of conducting the task of surface and area radiation monitoring including external monitoring of personnel. Once the extent and the intensity of radioactivity in an area is determined, good use of personnel can be made without too much risk. This is fortunate for the medical profession whose personnel can devote their talents to casualty care during or following nuclear warfare. Most individuals who know how to detect and measure the extent of radioactive contamination are also capable of conducting personnel decontamination operations and would do so if necessary. Consequently the spread of contamination can be minimized by adequate decontamination and the medical personnel can treat casualties who are relatively free of external radioactive contamination. The appropriate use of trained manpower and radiation detection equipment which are available in California combined with sufficient rehearsals prior to a nuclear war will greatly reduce any casualty damage due to radioactive fallout. The chances of survival of individuals can be greatly improved with a little knowledge of protection from radioactive contamination and of salvage of food and water. PMID:14409247

Of the necessity of knowledge of the natural pedo-geochemical background content in the evaluation of the contamination of soils by trace elements.

PubMed

Baize, D; Sterckeman, T

2001-01-08

In order to evaluate the contamination of the Dornach (Switzerland) site within the framework of the CEEM-Soil project, each participating team was allowed to take a maximum of 15 samples. The French team's sampling was organized in such a way as to answer the following questions: (i) what is the natural concentration of the soils at this site (local pedo-geochemical background content)?; (ii) what are the levels of Cd, Cu, Pb and Zn contamination of the soil?; (iii) what is the depth reached by the surface contamination that is derived from atmospheric fallout?; (iv) how is the contamination spread along the longest axis of the area under study? The relationships between total Fe and the trace metals have allowed local variations in the natural pedo-geochemical background content to be detected and thus permitted the anthropogenic contamination to be estimated. There would appear to be a low level of Pb contamination over all the site investigated (an increase of the order of 5-10 mg kg(-1) on the background level), limited to the surface humus-bearing layers. There is also a significant contamination by Cu over all of the site (an increase of the order of 30-40 mg kg(-1)). This contamination has remained in the surface horizons (0-20 cm). Very high Zn and Cd concentrations have been found in the four surface (0-4 cm) and deep horizons (15-70 cm) taken under the forest and very much lower values in the samples taken from cultivated soils. The most likely explanation is an unequal inheritance between the upper part of the site (wooded with thinner very clayey soils) and the lower cultivated part of the site (with thicker less clayey soils developed in a loamy material). For various reasons, it seems unlikely that a contamination of the wooded part should be so much higher than the cultivated part due to the interception of atmospheric dust by the trees. The local pedo-geochemical background Cd and Zn content of the upper wooded part proved to be clearly higher than that which would be encountered in most soils of Switzerland and France. Given this evaluation of the background content, it seems that only the surface horizons have been affected by Zn contamination (an addition of approx. 60-100 mg kg(-1)). In the case of Cd, the increase in concentrations is only 0.5-1 mg kg(-1) for the ploughed horizons, as well as the for the A horizons.

Non-Rayleigh Sea Clutter: Properties and Detection of Targets

DTIC Science & Technology

1976-06-25

subject should consult Guinard and Daley [7], which provides an overview of the theory and references all the I______.... important work. 6 * .-- - - S...results for scattering from slightly rough surfaces and composite surfaces obtained by Rice [1], Wright [2,3], Valenzuela [4-6], Guinard and Daley [7], and...for vertical polarization. In 1970, Trunk and George [10] considered the log-normal and contaminated-normal descriptions of sea clutter and calculated

Perchlorate Detection at Nanomolar Concentrations by Surface-Enhanced Raman Scattering

DTIC Science & Technology

2009-01-01

grooves/mm grating light path controlled by Renishaw WiRE software and analyzed by Galactic GRAMS software. RESULTS AND DISCUSSION Quantitative... Federal Rights License 14. ABSTRACT Perchlorate (ClO4 ) has emerged as a widespread environmental contaminant and has been detected in various food...by means of dynamic light scattering using a ZetaPlus particle size analyzer (Brookhaven Instruments, Holtsville, NY). Data were collected for every

Quantitative analysis of trace levels of surface contamination by X-ray photoelectron spectroscopy Part I: statistical uncertainty near the detection limit.

PubMed

Hill, Shannon B; Faradzhev, Nadir S; Powell, Cedric J

2017-12-01

We discuss the problem of quantifying common sources of statistical uncertainties for analyses of trace levels of surface contamination using X-ray photoelectron spectroscopy. We examine the propagation of error for peak-area measurements using common forms of linear and polynomial background subtraction including the correlation of points used to determine both background and peak areas. This correlation has been neglected in previous analyses, but we show that it contributes significantly to the peak-area uncertainty near the detection limit. We introduce the concept of relative background subtraction variance (RBSV) which quantifies the uncertainty introduced by the method of background determination relative to the uncertainty of the background area itself. The uncertainties of the peak area and atomic concentration and of the detection limit are expressed using the RBSV, which separates the contributions from the acquisition parameters, the background-determination method, and the properties of the measured spectrum. These results are then combined to find acquisition strategies that minimize the total measurement time needed to achieve a desired detection limit or atomic-percentage uncertainty for a particular trace element. Minimization of data-acquisition time is important for samples that are sensitive to x-ray dose and also for laboratories that need to optimize throughput.

Utilization of wavelength-shifting fibers coupled to ZnS(Ag) and plastic scintillator for simultaneous detection of alpha/beta particles

NASA Astrophysics Data System (ADS)

Ifergan, Y.; Dadon, S.; Israelashvili, I.; Osovizky, A.; Gonen, E.; Yehuda-Zada, Y.; Smadja, D.; Knafo, Y.; Ginzburg, D.; Kadmon, Y.; Cohen, Y.; Mazor, T.

2015-06-01

Low level radioactive surface contamination measurements require lightweight, large area and high efficiency detector. In most existing scintillation detectors there is a tradeoff between effective area and scintillation light collection. By using wavelength shifting (WLS) fibers the scintillation light may be collected efficiently also in a large area detector. In this study, WLS fibers were coupled to a beta sensitive plastic scintillator layer and to a alpha sensitive silver-activated zinc sulfide ZnS(Ag) layer for detecting both alpha and beta particles. The WLS fibers collect the scintillation light from the whole detector and transfer it to a single PMT. This first prototype unique configuration enables monitoring radioactive contaminated surfaces by both sides of the detector and provides high gamma rejection. In this paper, the detector structure, as well as the detector's measured linear response, will be described. The measured detection efficiency of 238Pu alpha particles (5.5 MeV) is 63%. The measured detection efficiency for beta particles is 89% for 90Sr-90Y (average energy of 195.8 keV, 934.8 keV), 50% for 36Cl (average energy of 251.3 keV), and 35% for 137Cs (average energy of 156.8 keV).

In Situ Biological Contamination Studies of the Moon: Implications for Future Planetary Protection and Life Detection Missions

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Kminek, Gerhard; Rummel, John D.

2010-01-01

NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moon, and future human exploration of Mars and other destinations. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require that all spacecraft and instrumentation be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there yet a planetary protection category for human missions. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future Mars surface exploration plans for a human mission to Mars.

DNA-labeled micro- and nanoparticles: a new approach to study contaminant transport in the subsurface

NASA Astrophysics Data System (ADS)

McNew, C.; Wang, C.; Kocis, T. N.; Murphy, N. P.; Dahlke, H. E.

2017-12-01

Though our understanding of contaminant behavior in the subsurface has improved, our ability to measure and predict complex contaminant transport pathways at hillslope to watershed scales is still lacking. By utilizing bio-molecular nanotechnology developed for nano-medicines and drug delivery, we are able to produce DNA-labeled micro- and nanoparticles for use in a myriad of environmental systems. Control of the fabrication procedure allows us to produce particles of custom size, charge, and surface functionality to mimic the transport properties of the particulate contaminant or colloid of interest. The use of custom sequenced DNA allows for the fabrication of an enormous number of unique particle labels (approximately 1.61 x 1060 unique sequences) and the ability to discern between varied spatial and temporal applications, or the transport effect of varied particle size, charge, or surface properties. To date, this technology has been utilized to study contaminant transport from lab to field scales, including surface and open channel flow applications, transport in porous media, soil retention, and even subglacial flow pathways. Here, we present the technology for production and detection of the DNA-labeled particles along with the results from a current hillslope study at the Sierra Foothills Research and Extension Center (SFREC). This field study utilizes spatial and temporal variations in DNA-labeled particle applications to identify subsurface pollutant transport pathways through the four distinct soil horizons present at the SFREC site. Results from this and previous studies highlight the tremendous potential of the DNA-labeled particle technology for studying contaminant transport through the subsurface.

Runoff of genotoxic compounds in river basin sediment under the influence of contaminated soils.

PubMed

da Costa, Thatiana Cappi; de Brito, Kelly Cristina Tagliari; Rocha, Jocelita Aparecida Vaz; Leal, Karen Alam; Rodrigues, Maria Lucia Kolowski; Minella, Jean Paolo Gomes; Matsumoto, Silvia Tamie; Vargas, Vera Maria Ferrão

2012-01-01

Contaminated sites must be analyzed as a source of hazardous compounds in the ecosystem. Contaminant mobility in the environment may affect sources of surface and groundwater, elevating potential risks. This study looked at the genotoxic potential of samples from a contaminated site on the banks of the Taquari River, RS, Brazil, where potential environmental problems had been identified (pentachlorophenol, creosote and hydrosalt CCA). Samplers were installed at the site to investigate the drainage material (water and particulate soil matter) collected after significant rainfall events. Organic extracts of this drained material, sediment river samples of the Taquari River (interstitial water and sediment organic extracts) were evaluated by the Salmonella/microsome assay to detect mutagenicity and by Allium cepa bioassays (interstitial water and whole sediment samples) to detect chromosomal alterations. Positive mutagenicity results in the Salmonella/microsome assay of the material exported from the area indicate that contaminant mixtures may have drained into the Taquari River. This was confirmed by the similarity of mutagenic responses (frameshift indirect mutagens) of organic extracts from soil and river sediment exported from the main area under the influence of the contaminated site. The Allium cepa test showed significant results of cytotoxicity, mutagenic index and chromosome aberration in the area under the same influence. However, it also showed the same similarity in positive results at an upstream site, which probably meant different contaminants. Chemical compounds such as PAHs, PCF and chromium, copper and arsenic were present in the runoff of pollutants characteristically found in the area. The strategy employed using the Salmonella/microsome assay to evaluate effects of complex contaminant mixtures, together with information about the main groups of compounds present, allowed the detection of pollutant dispersion routes from the contaminated site to the Taquari River sediment. Copyright © 2011 Elsevier Inc. All rights reserved.

Removing hexazinone from groundwater with microbial bioreactors

USDA-ARS?s Scientific Manuscript database

Hexazinone, a triazine herbicide that is often detected as a ground and surface water contaminant, inhibits electron transport in photosynthetic organisms and is toxic to primary producers that serve as the base of the food chain. This laboratory study evaluated the ability of two types of microbia...

Off site transport of fungicides with snowmelt and rainfall runoff from golf course fairway turf

USDA-ARS?s Scientific Manuscript database

Pesticides associated with the turfgrass industry have been detected in storm runoff and surface waters of urban watersheds; inferring contaminant contributions from residential, urban, and recreational sources. Golf course turf often requires multiple applications of pesticides at rates that exceed...

Joint Services Electronics Program Progress Report.

DTIC Science & Technology

1982-09-30

method has been successfully applied to scattering by submerged targets and to partially buried targets I0 . Other applications of our computational...The AES analyzer will enable us to detect possible contaminants on the sub- strate surface prior to MBR groqh as we have already done and to deter

Occurrence of anthropogenic organic compounds in ground water and finished water of community water systems in Eagle and Spanish Springs Valleys, Nevada, 2002-2004

USGS Publications Warehouse

Rosen, Michael R.; Shaefer, Donald H.; Toccalino, Patricia A.; Delzer, Gregory C.

2006-01-01

As a part of the U.S. Geological Survey's National Water-Quality Assessment Program, an effort to characterize the quality of major rivers and aquifers used as a source of supply to some of the largest community water systems (CWSs) in the United States has been initiated. These studies, termed Source Water-Quality Assessments (SWQAs), consist of two sampling phases. Phase 1 was designed to determine the frequency of detection and concentrations of about 260 volatile organic compounds (VOCs), pesticides and pesticide degradates, and other anthropogenic organic compounds in source water of 15 CWS wells in each study. Phase 2 monitors concentrations in the source water and also the associated finished water of CWSs for compounds most frequently detected during phase 1. One SWQA was completed in the Nevada Basin and Range area in Nevada. Ten CWS wells in Eagle Valley and five CWS wells in Spanish Springs Valley were sampled. For phase 2, two wells were resampled in Eagle Valley. Samples were collected during 2002-2004 for both phases. Water use in Eagle Valley is primarily for domestic purposes and is supplied through CWSs. Ground-water sources provide about 55 percent of the public-water supply, and surface-water sources supply about 45 percent. Lesser amounts of water are provided by domestic wells. Very little water is used for agriculture or manufacturing. Spanish Springs Valley has water-use characteristics similar to those in Eagle Valley, although there is more agricultural water use in Spanish Springs Valley than in Eagle Valley. Maximum contaminant concentrations were compared to two human-health benchmarks, if available, to describe the water-quality data in a human-health context for these findings. Measured concentrations of regulated contaminants were compared to U.S. Environmental Protection Agency and Nevada Maximum Contaminant Level (MCL) values. Measured concentrations of unregulated contaminants were compared to Health-Based Screening Levels, which are not regulatory standards and are not legally enforceable values. All of the contaminants detected in this study were found at concentrations less than available human-health benchmarks. In the source waters sampled in phase 1, 10 contaminants of the approximately 260 measured were detected in samples collected from Eagle Valley, and 4 contaminants were detected in samples from Spanish Springs Valley. The most frequently detected compounds in the Eagle Valley source water were chloroform (a disinfection by-product), which was detected in samples from four wells, and deethylatrazine (a degradation product of the herbicide atrazine), which was detected in samples from three wells. Each of the four contaminants detected in the Spanish Springs Valley source waters was detected in samples from one well. The detection frequencies of VOCs and pesticides in samples from the SWQA wells were similar to those in samples from both shallow and deep monitoring wells in Carson City, Reno, and Spanish Springs. This indicates that the SWQA sampling is representative of the organic chemical compounds likely to be detected in the aquifers sampled. However, more organic compounds were detected at low frequencies and concentrations in samples from the monitoring wells than in samples from SWQA wells. Three contaminants were detected in one finished-water sample collected from Eagle Valley. Comparison of SWQA results in the Nevada Basin and Range Study Unit to results of an SWQA in the larger urban area of Salt Lake City showed that fewer anthropogenic compounds were detected in Eagle and Spanish Springs Valleys and generally at lower concentrations than in the Salt Lake City study.

Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages.

PubMed

Hultman, Jenni; Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K Johanna

2015-10-01

Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected to culturing and amplicon sequence analyses. Abundant mesophilic psychrotrophs were detected within the microbiomes throughout the different compartments of the production plant environment. However, each of the main genera of food safety and quality interest, e.g., Leuconostoc, Brochothrix, and Yersinia, had their own characteristic patterns of contamination. Bacteria from the genus Leuconostoc, commonly causing spoilage of cold-stored, modified-atmosphere-packaged foods, were detected in high abundance (up to >98%) in the sausages studied. The same operational taxonomic units (OTUs) were, however, detected in lower abundances in raw meat and emulsion (average relative abundance of 2%±5%), as well as on the processing plant surfaces (<4%). A completely different abundance profile was found for OTUs phylogenetically close to the species Yersinia pseudotuberculosis. These OTUs were detected in high abundance (up to 28%) on the processing plant surfaces but to a lesser extent (<1%) in raw meat, sausage emulsion, and sausages. The fact that Yersinia-like OTUs were found on the surfaces of a high-hygiene packaging compartment raises food safety concerns related to their resilient existence on surfaces. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Streambed-material characteristics and surface-water quality, Green Pond Brook and tributaries, Picatinny Arsenal, New Jersey, 1983-90

USGS Publications Warehouse

Storck, D.A.; Lacombe, Pierre

1996-01-01

This report presents the results of a study designed to determine whether Green Pond Brook and its tributaries contain contaminated streambed sediments and to characterize the quaity of water in the brook. Results of previous investigations at Picatinny Arsenal, Morris County, New Jersey, indicate that significant contamination of ground water, surface water, and soil is present at the arsenal. Forty-five streambed-material samples were collected for analysis to determine whether contaminants have migrated to the brook from the surrounding area. Samples were analyzed for trace elements, base/neutral- and acid-etractable compounds, insecticides, and other constituents. Results of an electromagnetic-conductivity and natural-gamma-ray survey were used to describe the distribution of particle sizes in streambed and substreambed sediments. Historical results of analyses of streambed-material and surface-water samples also are presented. Samples of streambed material from three areas in Green Pond Brook and its tributaries contained organic and (or) inorganic constituents in concentrations greater than those typically found at the arsenal. These areas are Green Pond Brook, from the area near the outflow of Picatinny Lake downstream to Farley Avenue; Bear Swamp Brook, from the area near building 241 downstream to the confluence with Green Pond Brook; and Green Pond Brook, from the open burning area downstream to the dam near building 1178. Contaminants identified include trace elements, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine insecticides. Surface water in Green Pond Brook contained several volatile organic compounds, including trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene, at maximum concen- trations of 3.8, 4.6, and 11 micrograms per liter, respectively. Volatilization is expected to remove volatile organic compounds in the steep, fast- flowing reaches of the brook. No organic or inorganic constituents were detected in surface- water samples in concentrations greater than the U.S. Environmental Protection Agency primary drinking-water regulations. Only two constituents, iron and manganese, were detected in concen- trations greater than the U.S. Environmental Protection Agency secondary drinking-water regulations.

Assessment of personal airborne exposures and surface contamination from x-ray vaporization of beryllium targets at the National Ignition Facility.

PubMed

Paik, Samuel Y; Epperson, Patrick M; Kasper, Kenneth M

2017-06-01

This article presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 µg/100 cm 2 and 27 results were above the analytical reporting limit of 0.01 µg/100 cm 2 , for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present in workers' breathing zones. All the data thus far have shown that beryllium has been effectively managed to prevent exposures to workers during routine and non-routine work.

Assessment of personal airborne exposures and surface contamination from x-ray vaporization of beryllium targets at the National Ignition Facility

DOE PAGES

Paik, Samuel Y.; Epperson, Patrick M.; Kasper, Kenneth M.

2017-02-28

Here, this article presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measuresmore » in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 µg/100 cm 2 and 27 results were above the analytical reporting limit of 0.01 µg/100 cm 2, for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present in workers' breathing zones. Finally, all the data thus far have shown that beryllium has been effectively managed to prevent exposures to workers during routine and non-routine work.« less

Amchitka Island, Alaska, special sampling project 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

U.S. Department of Energy, Nevada Operations Office

2000-06-28

This 1997 special sampling project represents a special radiobiological sampling effort to augment the 1996 Long-Term Hydrological Monitoring Program (LTHMP) for Amchitka Island in Alaska. Lying in the western portion of the Aleutian Islands arc, near the International Date Line, Amchitka Island is one of the southernmost islands of the Rat Island Chain. Between 1965 and 1971, the U.S. Atomic Energy Commission conducted three underground nuclear tests on Amchitka Island. In 1996, Greenpeace collected biota samples and speculated that several long-lived, man-made radionuclides detected (i.e., americium-241, plutonium-239 and -240, beryllium-7, and cesium-137) leaked into the surface environment from underground cavitiesmore » created during the testing. The nuclides of interest are detected at extremely low concentrations throughout the environment. The objectives of this special sampling project were to scientifically refute the Greenpeace conclusions that the underground cavities were leaking contaminants to the surface. This was achieved by first confirming the presence of these radionuclides in the Amchitka Island surface environment and, second, if the radionuclides were present, determining if the source is the underground cavity or worldwide fallout. This special sampling and analysis determined that the only nonfallout-related radionuclide detected was a low level of tritium from the Long Shot test, which had been previously documented. The tritium contamination is monitored and continues a decreasing trend due to radioactive decay and dilution.« less

The impact of human activities on sediments of San Francisco Bay, California: an overview

USGS Publications Warehouse

van Geen, Alexander; Luoma, Samuel N.

1999-01-01

This note introduces a set of eight papers devoted to a detailed study of two sediment cores from San Francisco Bay with an overview of the region and a chronology of human activities. Data used in this study to constrain the range of sediment ages at different depths include , and  concentrations in the sediment and the  age of shell fragments. In order of first detectable appearance in the record, the indicators of contamination that were analyzed include PAHs>Hg>Ag, Cu, Pb, Zn>DDT, PCB>foraminiferal Cd/Ca. This study also documents a large memory effect for estuarine contamination caused by sediment mixing and resuspension. Once an estuary such as San Francisco Bay has been contaminated, decades must pass before contaminant levels in surface sediment will return to background levels, even if external contaminant inputs have been entirely eliminated.

In situ measurement of radioactive contamination of bottom sediments.

PubMed

Zhukouski, A; Anshakou, O; Kutsen, S

2018-04-30

A gamma spectrometric method is presented for in situ radiation monitoring of bottom sediments with contaminated layer of unknown thickness to be determined. The method, based on the processing of experimental spectra using the results of their simulation by the Monte Carlo method, is proposed and tested in practice. A model for the transport of gamma radiation from deposited radionuclides 137 Cs and 134 Cs to a scintillation detection unit located on the upper surface of the contaminated layer of sediments is considered. The relationship between the effective radius of the contaminated site and the thickness of the layer has been studied. The thickness of the contaminated layer is determined by special analysis of experimental and thickness-dependent simulated spectra. The technique and algorithm developed are verified as a result of full-scale studies performed with the submersible gamma-spectrometer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessment of the Unintentional Reuse of Municipal Wastewater

NASA Astrophysics Data System (ADS)

Okasaki, S.; Fono, L.; Sedlak, D. L.; Dracup, J. A.

2002-12-01

Many surface waters that receive wastewater effluent also serve as source waters for drinking water treatment plants. Recent research has shown that a number of previously undiscovered wastewater-derived contaminants are present in these surface waters, including pharmaceuticals and human hormones, several of which are suspected carcinogens or endocrine disrupters and are, as of yet, unregulated through drinking water standards. This research has been designed to determine the extent of contamination of specific wastewater-derived contaminants in surface water bodies that both receive wastewater effluent and serve as a source of drinking water to a sizeable population. We are testing the hypothesis that surface water supplies during low flow are potentially of worse quality than carefully monitored reclaimed water. The first phase of our research involves: (1) the selection of sites for study; (2) a hydrologic analysis of the selected sites to determine average flow of the source water during median- and low-flow conditions; and (3) the development and testing of chemical analyses, including both conservative and reactive tracers that have been studied in microcosms and wetlands for attenuation rates. The second phase involves the development and use of the hydrologic model QUAL2E to simulate each of the selected watersheds in order to estimate potential stream water quality impairments at the drinking water intake at each site. The results of the model are verified with field sampling at designated locations at each site. We expect to identify several critical river basins where surface water at the drinking water intake contains sufficient wastewater-derived contaminants to warrant concern. If wastewater-derived contaminants are detected, we will estimate the average annual exposure of consumers of this water. We will compare these expected and actual concentrations with typical constituent concentrations found in wastewater that has undergone advanced treatment for reclamation. We may demonstrate that the surface water supplies during low flow are actually of worse quality than carefully monitored reclaimed water.

Efficacy of low-pressure foam cleaning compared to conventional cleaning methods in the removal of bacteria from surfaces associated with convenience food.

PubMed

Lambrechts, A A; Human, I S; Doughari, J H; Lues, J F R

2014-09-01

Food borne illnesses and food poisoning are cause for concern globally. The diseases are often caused by food contamination with pathogenic bacteria due largely to poor sanitary habits or storage conditions. Prevalence of some bacteria on cleaned and sanitised food contact surfaces from eight convenience food plants in Gauteng (South Africa) was investigated with the view to evaluate the efficacy of the cleaning methods used with such food contact surfaces. The microbial load of eight convenience food manufacturing plants was determined by sampling stainless steel food contact surfaces after they had been cleaned and sanitised at the end of a day's shift. Samples were analysed for Total Plate Count (TPC), Escherichia coli, Salmonella species, Staphylococcus aureus and Listeria species. Results showed that 59 % of the total areas sampled for TPC failed to comply with the legal requirements for surfaces, according to the Foodstuffs, Cosmetics and Disinfectants Act (< 100 cfu.cm(-2)). S. aureus and Salmonella were not detected, but Listeria was detected in 23 % and E. coli in 1.3 % of the samples. Fifty percent (50 %) of the plants applied conventional cleaning methods for cleaning and sanitation and 50 % used the low-pressure foam (LPF) method. There was significant difference (P ≤ 0.05) between the mean TPC values of the conventional cleaning method (14 358.82) compared to that of LPF method (2 386.51) but no significant difference (P > 0.05) in terms of Listeria species isolates obtained from both cleaning methods. The LPF method proved to be the superior cleaning option for lowering TPC counts. Regardless of cleaning method used, pathogens continued to flourish on various surfaces, including dry stainless steel, posing a contamination hazard for a considerable period depending on the contamination level and type of pathogen. Intensive training for proper chemical usage and strict procedural compliance among workers for efficient cleaning procedures is recommended.

Could arsenic mitigation lead to increased diarrheal disease in Bangladesh?

NASA Astrophysics Data System (ADS)

van Geen, A.; Ahmed, K.; Akita, Y.; Alam, M.; Culligan, P.; Feighery, J.; Ferguson, A. S.; Emch, M.; Escamilla, V.; Knappett, P.; Layton, A.; Mailloux, B. J.; McKay, L. D.; Mey, J. L.; Serre, M. L.; Streatfield, P. K.; Wu, J.; Yunus, M.

2010-12-01

Could arsenic mitigation lead to increased diarrheal disease in Bangladesh? The health risks of As exposure caused by the installation of millions of shallow tubewells in the Bengal Basin are widely known but fecal contamination of groundwater in this densely populated region with poor sanitation has rarely been studied systematically. In order to examine the degree of microbial contamination of groundwater and, specifically, determine whether arsenic mitigation by switching between shallow wells might affect exposure to microbial pathogens, 125 tubewells ranging between 20 and 120 ft in depth and spanning a wide range of As concentrations were monitored monthly for the fecal indicator E. coli across 7 villages of Matlab and Araihazar, Bangladesh. Overall, the fraction of shallow wells with detectable E. coli ranged from 20% during the dry season to 70% during the monsoon. The linear relation observed between the frequency of E. coli detection in well water during the monsoon and population residing within 25 m of a well (p<0.05) indicates a link between aquifer contamination and population density that might be explained by variations in overlying fecal source strength, coupled with rapid infiltration of surface contaminants into the aquifer. Neither well depth within the 20-120 ft range nor the presence of a concrete platform at the surface had a detectable impact on E. coli levels in well water. PCR analysis of groundwater from 50 wells where E. coli was detected (i.e. >1 CFU/100 mL) indicates that 40% of the wells contained a known pathogen such as Shigella, rotavirus or pathogenic E. coli. Detection of E. coli was on average higher by two-thirds in shallow wells with up to 10 ug/L As compared to shallow wells with >50 ug/L As. This raises the possibility that the most widely applied form of As mitigation, switching to a neighboring household’s low-As well, could result in increased exposure to microbial pathogens. The inverse relation between E. coli detection frequency and groundwater As may reflect the shorter hydraulic travel time to shallow low-As aquifers compared to high-As aquifers that has been reported previously. The relevance to human health of microbial contaminants contained in groundwater in South Asia is supported by significantly higher rates of diarrheal disease in children under 5 recorded in 2000-06 in Matlab for households using a shallow low-As well compared to households using a shallow high-As well, controlling for the effects of population density, socio-economic status, and flood control.

Slit lamps and lenses: a potential source of nosocomial infections?

PubMed

Sobolewska, Bianka; Buhl, Michael; Liese, Jan; Ziemssen, Focke

2018-01-30

The aim of the study was to evaluate the bacterial contamination level of contact surfaces on slit lamps and the grip areas of lenses. Within unannounced audits, two regions of the slit lamps (headrest and joystick), indirect ophthalmoscopy devices, and ultrasound probes were obtained with rayon-tipped swab. Non-contact lenses used for indirect fundoscopy were pressed on RODAC (Replicate Organism Detection and Counting) plates. One hundred and eighty-one surfaces were sampled. The total number of colony-forming units was assessed and bacterial species were identified. Spa-typing and antimicrobial susceptibility testing were performed from Staphylococcus aureus isolates. Among the total bacterial isolates from ophthalmological equipment (lenses: 51 of 78, slit lamps: 43 of 88, ophthalmoscopy helmets: 3 of 8, ultrasound probes: 2 of 7), coagulase-negative staphylococci (CNS) was most frequently found, followed by Micrococcus spp. (lenses vs. slit lamps: P < 0.001 and P = 0.01, respectively). The bacterial contamination of lenses (76%) was significantly higher than that of slit lamps (54%) (P < 0.003). A significantly higher contamination with CNS was observed on lenses from residents vs. from consultants (78% vs. 35%, P = 0.01). A total of seven different spa-types of S. aureus were isolated. No correlation was found between S. aureus contamination of different ophthalmological equipments (Spearman's rank correlation coefficient, ρ = 0.04, P = 0.75). Methicillin-resistant S. aureus was not detected. Bacterial species of the normal skin flora were isolated from the ophthalmological equipment. The bacterial contamination of the portable devices was significantly higher than that of slit lamps. Therefore, proper hygiene of the mobile instruments should be monitored in order to prevent transmission of bacteria in residents and consultants.

Male-specific coliphages for source tracking fecal contamination in surface waters and prevalence of Shiga-toxigenic Escherichia coli in a major produce production region of the Central Coast of California.

PubMed

Ravva, Subbarao V; Sarreal, Chester Z; Cooley, Michael B

2015-07-01

To provide data for traditional trace-back studies from fork to farm, it is necessary to determine the environmental sources for Shiga-toxigenic Escherichia coli. We developed SYBR green based reverse-transcriptase PCR methods to determine the prevalence of F+ RNA coliphages (FRNA) as indicators of fecal contamination. Male-specific coliphages, determined using a single-agar overlay method, were prevalent in all surface waters sampled for 8 months. F+ DNA coliphages (FDNA) were predominant compared to FRNA in water samples from majority of sampling locations. Most (90%) of the FRNA were sourced to humans and originated from human-impacted sites. Members of genogroup III represented 77% of FRNA originated from human sources. Furthermore, 93% of FRNA sourced to animals were also detected in water samples from human-impacted sites. Eighty percent of all FRNA were isolated during the winter months indicating seasonality in prevalence. In contrast, FDNA were more prevalent during summer months. E. coli O157:H7 and Shiga-toxigenic E. coli were detected in water samples from locations predominantly influenced by agriculture. Owing to their scarcity, their numbers could not be correlated with the prevalence of FRNA or FDNA in water samples. Both coliform bacteria and generic E. coli from agricultural or human-impacted sites were similar in numbers and thus could not be used to determine the sources of fecal contamination. Data on the prevalence of male-specific coliphages may be invaluable for predicting the sources of fecal contamination and aid in developing methods to prevent enteric pathogen contamination from likely sources during produce production.

Extensive severe fever with thrombocytopenia syndrome virus contamination in surrounding environment in patient rooms.

PubMed

Ryu, B-H; Kim, J Y; Kim, T; Kim, M-C; Kim, M J; Chong, Y-P; Lee, S-O; Choi, S-H; Kim, Y S; Woo, J H; Kim, S-H

2018-01-31

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease in Korea and China. Although there is previous evidence of person-to-person transmission via direct contact with body fluids, the role of environmental contamination by SFTS virus (SFTSV) in healthcare settings has not been established. We therefore investigated the contamination of the healthcare environment by SFTSV. We investigated the possible contamination of hospital air and surfaces with SFTSV transmission by collecting air and swabbing environmental surface samples in two hospitals treating six SFTS patients between March and September 2017. The samples were tested using real-time RT-PCR for SFTS M and S segments. Of the six SFTS patients, four received mechanical ventilation and three died. Five rooms were occupied by those using mechanical ventilation or total plasma exchange therapy in isolation rooms without negative pressure and one room was occupied by a patient bedridden due to SFTS. SFTSV was detected in 14 (21%) of 67 swab samples. Five of 24 swab samples were obtained from fomites including stethoscopes, and 9 of 43 were obtained from fixed structures including doorknobs and bed guardrails. Some samples from fixed structures such as television monitors and sink tables were obtained in areas remote from the patients. SFTSV RNA was not detected in five air samples from three patients' rooms. Our data suggest that SFTSV contamination was extensive in surrounding environments in SFTS patients' rooms. Therefore, more strict isolation methods and disinfecting procedures should be considered when managing SFTS patients. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Spatiotemporal appraisal of TBT contamination and imposex along a tropical bay (Todos os Santos Bay, Brazil).

PubMed

Artifon, Vanda; Castro, Ítalo Braga; Fillmann, Gilberto

2016-08-01

A spatiotemporal evaluation of butyltin contamination was performed between 2010 and 2012 along Todos os Santos Bay (Northeast Brazil) using surface sediments, bivalve tissues (Anomalocardia brasiliana and Mytella guyanensis), and imposex occurrence (Stramonita rustica). The spatial study detected high tributyltin (TBT) levels (maximum values of 262 ng Sn g (-1) - 21,833 ng Sn g(-1) of total organic carbon - for surface sediments and 421 ng Sn g(-1) for bivalve tissues) in the innermost part of the bay. The TBT levels detected in M. guyanensis tissues might cause human health risk since local population consumes these organisms. These high concentrations observed in the bivalves might result in ingestions higher than the safe limits established by European Food Safety Authority (250 ng TBT kg(-1) day(-1)). Considering the temporal evaluation, no difference (p > 0.05) was observed between TBT concentrations in sediments obtained during the two sampling campaigns (2010/2011 and 2012). However, the increasing predominance of TBT metabolites (butyltin degradation index (BDI) >1) in more recent sediments indicates further degradation of old TBT inputs. In spite of that, recent inputs are still evident at this region. Nevertheless, a reduction of imposex parameters in S. rustica over the last decade suggests an overall decline in the TBT contamination, at least in the outermost and possible less impacted region of the bay. The TBT contamination is probably reducing due to the national and international legislative restrictions on the use of TBT as antifouling biocide. The contamination levels, however, are still relevant especially in the inner part of Todos os Santos Bay since they are above those that are likely to cause toxicity to the biota.

Monitoring for Pesticides in Groundwater and Surface Water in Nevada, 2008

USGS Publications Warehouse

Thodal, Carl E.; Carpenter, Jon; Moses, Charles W.

2009-01-01

Commercial pesticide applicators, farmers, and homeowners apply about 1 billion pounds of pesticides annually to agricultural land, non-crop land, and urban areas throughout the United States (Gilliom and others, 2006, p. 1). The U.S. Environmental Protection Agency (USEPA) defines a pesticide as any substance used to kill or control insects, weeds, plant diseases, and other pest organisms. Although there are important benefits from the proper use of pesticides, like crop protection and prevention of human disease outbreaks, there are also risks. One risk is the contamination of groundwater and surface-water resources. Data collected during 1992-2001 from 51 major hydrologic systems across the United States indicate that one or more pesticide or pesticide breakdown product was detected in more than 50 percent of 5,057 shallow (less than 20 feet below land surface) wells and in all of the 186 stream sites that were sampled in agricultural and urban areas (Gilliom and others, 2006, p. 2-4). Pesticides can contaminate surface water and groundwater from both point sources and non-point sources. Point sources are from specific locations such as spill sites, disposal sites, pesticide drift during application, and application of pesticides to control aquatic pests. Non-point sources represent the dominant source of surface water and groundwater contamination and may include agricultural and urban runoff, erosion, leaching from application sites, and precipitation that has become contaminated by upwind applications. Pesticides typically enter surface water when rainfall or irrigation exceeds the infiltration capacity of soil and resulting runoff then transports pesticides to streams, rivers, and other surface-water bodies. Contamination of groundwater may result directly from spills near poorly sealed well heads and from pesticide applications through improperly designed or malfunctioning irrigation systems that also are used to apply pesticides (chemigation; Carpenter and Johnson, 1997). Groundwater contamination also may come indirectly by the percolation of agricultural and urban irrigation water through soil layers and into groundwater and from pesticide residue in surface water, such as drainage ditches, streams, and municipal wastewater. To protect surface water and groundwater from pesticide contamination, the USEPA requires that all states establish a pesticide management plan. The Nevada Department of Agriculture (NDOA), with assistance from the USEPA, developed a management program of education (Hefner and Donaldson, 2006), regulation (Johnson and others, 2006), and monitoring (Pennington and others, 2001) to protect Nevada's water resources from pesticide contaminants. Sampling sites are located in areas where urban or agricultural pesticide use may affect groundwater, water bodies, endangered species, and other aquatic life. Information gathered from these sites is used by NDOA to help make regulatory decisions that will protect human and environmental health by reducing and eliminating the occurrence of pesticide contamination. This fact sheet describes current (2008) pesticide monitoring of groundwater and streams by the NDOA in Nevada and supersedes Pennington and others (2001).

Soil, Groundwater, Surface Water, and Sediments of Kennedy Space Center, Florida: Background Chemical and Physical Characteristics

NASA Technical Reports Server (NTRS)

Shmalzer, Paul A.; Hensley, Melissa A.; Mota, Mario; Hall, Carlton R.; Dunlevy, Colleen A.

2000-01-01

This study documented background chemical composition of soils, groundwater, surface; water, and sediments of Kennedy Space Center. Two hundred soil samples were collected, 20 each in 10 soil classes. Fifty-one groundwater wells were installed in 4 subaquifers of the Surficial Aquifer and sampled; there were 24 shallow, 16 intermediate, and 11 deep wells. Forty surface water and sediment samples were collected in major watershed basins. All samples were away from sites of known contamination. Samples were analyzed for organochlorine pesticides, aroclors, chlorinated herbicides, polycyclic aromatic hydrocarbons (PAH), total metals, and other parameters. All aroclors (6) were below detection in all media. Some organochlorine pesticides were detected at very low frequencies in soil, sediment, and surface water. Chlorinated herbicides were detected at very low frequencies in soil and sediments. PAH occurred in low frequencies in soiL, shallow groundwater, surface water, and sediments. Concentrations of some metals differed among soil classes, with subaquifers and depths, and among watershed basins for surface water but not sediments. Most of the variation in metal concentrations was natural, but agriculture had increased Cr, Cu, Mn, and Zn.

Design and analysis of surface plasmon resonance (SPR) sensor to check the quality of food from adulteration

NASA Astrophysics Data System (ADS)

Kumar, Manish; Raghuwanshi, Sanjeev Kumar

2018-02-01

In recent years, food safety issues caused by contamination of chemical substances or microbial species have raised a major area of concern to mankind. The conventional chromatography-based methods for detection of chemical are based on human-observation and slow for real-time monitoring. The surface plasmon resonance (SPR) sensors offers the capability of detection of very low concentrations of adulterated chemical and biological agents for real-time by monitoring. Thus, adulterant agent in food gives change in refractive index of pure food result in corresponding phase change. These changes can be detected at the output and can be related to the concentration of the chemical species present at the point.

Assumptions of acceptance sampling and the implications for lot contamination: Escherichia coli O157 in lots of Australian manufacturing beef.

PubMed

Kiermeier, Andreas; Mellor, Glen; Barlow, Robert; Jenson, Ian

2011-04-01

The aims of this work were to determine the distribution and concentration of Escherichia coli O157 in lots of beef destined for grinding (manufacturing beef) that failed to meet Australian requirements for export, to use these data to better understand the performance of sampling plans based on the binomial distribution, and to consider alternative approaches for evaluating sampling plans. For each of five lots from which E. coli O157 had been detected, 900 samples from the external carcass surface were tested. E. coli O157 was not detected in three lots, whereas in two lots E. coli O157 was detected in 2 and 74 samples. For lots in which E. coli O157 was not detected in the present study, the E. coli O157 level was estimated to be <12 cells per 27.2-kg carton. For the most contaminated carton, the total number of E. coli O157 cells was estimated to be 813. In the two lots in which E. coli O157 was detected, the pathogen was detected in 1 of 12 and 2 of 12 cartons. The use of acceptance sampling plans based on a binomial distribution can provide a falsely optimistic view of the value of sampling as a control measure when applied to assessment of E. coli O157 contamination in manufacturing beef. Alternative approaches to understanding sampling plans, which do not assume homogeneous contamination throughout the lot, appear more realistic. These results indicate that despite the application of stringent sampling plans, sampling and testing approaches are inefficient for controlling microbiological quality.

Risk screening for exposure to groundwater pollution in a wastewater irrigation district of the Mexico City region.

PubMed

Downs, T J; Cifuentes-García, E; Suffet, I M

1999-07-01

Untreated wastewater from the Mexico City basin has been used for decades to irrigate cropland in the Mezquital Valley, State of Hidalgo, Mexico. Excess irrigation water recharges the near-surface aquifer that is used as a domestic water supply source. We assessed the groundwater quality of three key groundwater sources of domestic water by analyzing for 24 trace metals, 67 target base/neutral/acid (BNA) organic compounds, nontarget BNA organics, 23 chlorinated pesticides, 20 polychlorinated biphenyls, and nitrate, as well as microbiological contaminants--coliforms, Vibrio cholerae, and Salmonella. Study participants answered a questionnaire that estimated ingestion and dermal exposure to groundwater; 10% of the sample reported frequent diarrhea and 9% reported persistent skin irritations. Detection of V. cholerae non-01 in surface waters at all sites suggested a potential risk (surrogate indicator present) of diarrheal disease for canal and river bathers by accidental ingestion, as well as potential Vibrio contamination of near-surface groundwater and potential cholera risk, magnified by lapses in disinfection. High total coliform levels in surface water and lower levels in groundwater at all sites indicated fecal contamination and a potential risk of gastrointestinal disease in populations exposed to inadequately disinfected groundwater. Using chemical criteria, no significant risk from ingestion or dermal contact was identified at the method detection limits at any site, except from nitrate exposure: infants and young children are at risk from methemoglobinemia at all sites. Results suggest that pathogen risk interventions are a priority, whereas nitrate risk needs further characterization to determine if formal treatment is needed. The risks exist inside and outside the irrigation district. The method was highly cost-effective.

Risk screening for exposure to groundwater pollution in a wastewater irrigation district of the Mexico City region.

PubMed Central

Downs, T J; Cifuentes-García, E; Suffet, I M

1999-01-01

Untreated wastewater from the Mexico City basin has been used for decades to irrigate cropland in the Mezquital Valley, State of Hidalgo, Mexico. Excess irrigation water recharges the near-surface aquifer that is used as a domestic water supply source. We assessed the groundwater quality of three key groundwater sources of domestic water by analyzing for 24 trace metals, 67 target base/neutral/acid (BNA) organic compounds, nontarget BNA organics, 23 chlorinated pesticides, 20 polychlorinated biphenyls, and nitrate, as well as microbiological contaminants--coliforms, Vibrio cholerae, and Salmonella. Study participants answered a questionnaire that estimated ingestion and dermal exposure to groundwater; 10% of the sample reported frequent diarrhea and 9% reported persistent skin irritations. Detection of V. cholerae non-01 in surface waters at all sites suggested a potential risk (surrogate indicator present) of diarrheal disease for canal and river bathers by accidental ingestion, as well as potential Vibrio contamination of near-surface groundwater and potential cholera risk, magnified by lapses in disinfection. High total coliform levels in surface water and lower levels in groundwater at all sites indicated fecal contamination and a potential risk of gastrointestinal disease in populations exposed to inadequately disinfected groundwater. Using chemical criteria, no significant risk from ingestion or dermal contact was identified at the method detection limits at any site, except from nitrate exposure: infants and young children are at risk from methemoglobinemia at all sites. Results suggest that pathogen risk interventions are a priority, whereas nitrate risk needs further characterization to determine if formal treatment is needed. The risks exist inside and outside the irrigation district. The method was highly cost-effective. Images Figure 1 PMID:10398590

Concentrations of organic contaminants detected during managed flow conditions, San Joaquin River and Old River, California, 2001

USGS Publications Warehouse

Orlando, James L.; Kuivila, Kathryn

2005-01-01

Concentrations of organic contaminants were determined in water samples collected at six surface-water sites located along the San Joaquin and Old Rivers during April through June 2001. Water samples were collected, coincident with salmon smolt caging studies conducted by researchers from the Bodega Marine Laboratory at the University of California at Davis to characterize exposure of the salmon smolt to organic contaminants. Sampling occurred prior to, during, and following the implementation of managed streamflow conditions on the San Joaquin and Old Rivers as part of the Vernalis Adaptive Management Plan. Thirteen pesticides were detected in water samples collected during this study, and at least five pesticides were detected in each sample. The total number of pesticide detections varied little between river systems and between sites, but the maximum concentrations of most pesticides occurred in San Joaquin River samples. The total number of pesticides detected varied little over the three time periods. However, during the period of managed streamflow, the fewest number of pesticides were detected at their absolute maximum concentration. Nine wastewater compounds were detected during this study. Suspended-sediment concentrations were similar for the San Joaquin and Old Rivers except during the period of managed streamflow conditions, when suspended-sediment concentration was higher at sites on the San Joaquin River than at sites on the Old River. Values for water parameters (pH, specific conductance, and hardness) were lowest during the period of managed flows.

Sources and ages of fine-grained sediment to streams using fallout radionuclides in the Midwestern United States

USGS Publications Warehouse

Gellis, Allen; Fuller, Christopher C.; Van Metre, Peter C.

2017-01-01

Fallout radionuclides, 7Be and 210Pbex, sampled in bed sediment for 99 watersheds in the Midwestern region of the United States and in 15 samples of suspended sediment from 3 of these watersheds were used to partition upland from channel sources and to estimate the age or the time since the surface-derived portion of sediment was on the land surface (0–∼1 year). Channel sources dominate: 78 of the 99 bed material sites (79%) have >50% channel-derived sediment, and 9 of the 15 suspended-sediment samples (60%) have >50% channel-derived sediment. 7Be was detected in 82 bed sediment samples and all 15 suspended-sediment samples. The surface-derived portion of 54 of the 80 (68%) streams with detectable 7Be and 210Pbex were ≤ 100 days old and the surface-derived portion of all suspended-sediment samples were ≤ 100 days old, indicating that surface-derived fine-grained sediment moves rapidly though these systems. The concentrations of two hydrophobic pesticides–DDE and bifenthrin–are correlated with the proportion of surface-derived sediment, indicating a link between geomorphic processes and particle-associated contaminants in streams. Urban areas had the highest pesticide concentrations and the largest percentage of surface-derived sediment. Although the percentage of surface-derived sediment is less than channel sources at most of the study sites, the relatively young age of the surface-derived sediment might indicate that management actions to reduce sediment contamination where the land surface is an important source could have noticeable effects.

Detection of hepatitis E virus and other livestock-related pathogens in Iowa streams

USDA-ARS?s Scientific Manuscript database

Manure application is a major source of pathogens to the environment. Through overland runoff and tile drainage, these pathogens contaminate surface water and stream bed sediment. Some of these pathogens are zoonotic that can potentially affect both animal and human health. This study examined the p...

Challenging a bioinformatic tool's ability to detect microbial contaminants using in silico whole genome sequencing data.

PubMed

Olson, Nathan D; Zook, Justin M; Morrow, Jayne B; Lin, Nancy J

2017-01-01

High sensitivity methods such as next generation sequencing and polymerase chain reaction (PCR) are adversely impacted by organismal and DNA contaminants. Current methods for detecting contaminants in microbial materials (genomic DNA and cultures) are not sensitive enough and require either a known or culturable contaminant. Whole genome sequencing (WGS) is a promising approach for detecting contaminants due to its sensitivity and lack of need for a priori assumptions about the contaminant. Prior to applying WGS, we must first understand its limitations for detecting contaminants and potential for false positives. Herein we demonstrate and characterize a WGS-based approach to detect organismal contaminants using an existing metagenomic taxonomic classification algorithm. Simulated WGS datasets from ten genera as individuals and binary mixtures of eight organisms at varying ratios were analyzed to evaluate the role of contaminant concentration and taxonomy on detection. For the individual genomes the false positive contaminants reported depended on the genus, with Staphylococcus , Escherichia , and Shigella having the highest proportion of false positives. For nearly all binary mixtures the contaminant was detected in the in-silico datasets at the equivalent of 1 in 1,000 cells, though F. tularensis was not detected in any of the simulated contaminant mixtures and Y. pestis was only detected at the equivalent of one in 10 cells. Once a WGS method for detecting contaminants is characterized, it can be applied to evaluate microbial material purity, in efforts to ensure that contaminants are characterized in microbial materials used to validate pathogen detection assays, generate genome assemblies for database submission, and benchmark sequencing methods.

Demonstration and Evaluation of Solid Phase Microextraction for the Assessment of Bioavailability and Contaminant Mobility

DTIC Science & Technology

2012-05-01

methods demonstrated that desorption into solvents suitable for subsequent chemical analysis (into acetonitrile for HPLC analysis or hexane for GC...SPME. Analysis by HPLC with EPA 8310 with fluorescent detection. a) surface water quality criteria (NRWQC) are given for comparison to detection... analysis ) or hexane (for PCB analysis ) was added to the inserts. The vials were then analyzed directly by HPLC (PAHs) or GC-ECD (PCBs). Fiber achieved

Selective flow path alpha particle detector and method of use

DOEpatents

Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

2002-01-01

A method and apparatus for monitoring alpha contamination are provided in which ions generated in the air surrounding the item, by the passage of alpha particles, are moved to a distant detector location. The parts of the item from which ions are withdrawn can be controlled by restricting the air flow over different portions of the apparatus. In this way, detection of internal and external surfaces separately, for instance, can be provided. The apparatus and method are particularly suited for use in undertaking alpha contamination measurements during the commissioning operations.

Laboratory investigations: Low Earth orbit environment chemistry with spacecraft surfaces

NASA Technical Reports Server (NTRS)

Cross, Jon B.

1990-01-01

Long-term space operations that require exposure of material to the low earth orbit (LEO) environment must take into account the effects of this highly oxidative atmosphere on material properties and the possible contamination of the spacecraft surroundings. Ground-based laboratory experiments at Los Alamos using a newly developed hyperthermal atomic oxygen (AO) source have shown that not only are hydrocarbon based materials effected but that inorganic materials such as MoS2 are also oxidized and that thin protective coatings such as Al2O3 can be breached, producing oxidation of the underlying substrate material. Gas-phase reaction products, such as SO2 from oxidation of MoS2 and CO and CO2 from hydrocarbon materials, have been detected and have consequences in terms of spacecraft contamination. Energy loss through gas-surface collisions causing spacecraft drag has been measured for a few select surfaces and has been found to be highly dependent on the surface reactivity.

Modeling Cryptosporidium and Giardia in Ground and Surface Water Sources in Rural India: Associations with Latrines, Livestock, Damaged Wells, and Rainfall Patterns

PubMed Central

2016-01-01

Surface and groundwater contamination with fecal pathogens is a public health concern especially in low-income settings where these sources are used untreated. We modeled observed Cryptosporidium and Giardia contamination in community ponds (n = 94; 79% contaminated), deep tubewells (DTWs) (n = 107; 17%), and shallow tubewells (STWs) (n = 96; 19%) during the 2012 and 2013 monsoon seasons (June–August) in 60 villages in Puri District, India to understand sources and processes of contamination. Detection of Cryptosporidium and/or Giardia in a tubewell was positively associated with damage to the well pad for DTWs, the amount of human loading into pour-flush latrine pits nearby (≤15 m) for STWs, and the village literacy rate (for Giardia in STWs). Pond concentration levels were positively associated with the number of people practicing open defecation within 50 m and the sheep population for Cryptosporidium, and with the village illiteracy rate for Giardia. Recent rainfall increased the risk of Cryptosporidium in STWs (an extreme event) and ponds (any), while increasing seasonal rainfall decreased the risk of Giardia in STWs and ponds. Full latrine coverage in this setting is expected to marginally reduce pond Cryptosporidium contamination (16%) while increasing local groundwater protozoal contamination (87–306%), with the largest increases predicted for Cryptosporidium in STWs. PMID:27310009

Characterization of Listeria monocytogenes isolated from a fresh mixed sausage processing line in Pelotas-RS by PFGE

PubMed Central

von Laer, Ana Eucares; de Lima, Andréia Saldanha; Trindade, Paula dos Santos; Andriguetto, Cristiano; Destro, Maria Teresa; da Silva, Wladimir Padilha

2009-01-01

Listeria monocytogenes is a bacterium capable to adhere to the surfaces of equipment and utensils and subsequently form biofilms. It can to persist in the food processing environmental for extended periods of time being able to contaminate the final product. The aim of this study was to trace the contamination route of L. monocytogenes on a fresh mixed sausage processing line, from raw material to the final product. The isolates obtained were characterized by serotyping and molecular typing by pulsed-field gel electrophoresis (PFGE) using the restriction enzymes ApaI and AscI. L. monocytogenes was detected in 25% of the samples. The samples of raw material were not contaminated, however, the microorganism was detected in 21% of the environmental samples (food contact and non-food contact), 20.8% of the equipments, 20% of the food worker’s hands, 40% of the mass ready to packaging and in all the final products samples, demonstrating that the contamination of final product occurred during the processing and the importance of cross contamination. PFGE yielded 22 pulsotypes wich formed 7 clusters, and serotyping yielded 3 serotypes and 1 serogroup, however, the presence of serotypes 4b and 1/2b in the final product is of great concern for public health. The tracing of contamination showed that some strains are adapted and persisted in the processing environment in this industry. PMID:24031402

A national-scale assessment of micro-organic contaminants in groundwater of England and Wales.

PubMed

Manamsa, Katya; Crane, Emily; Stuart, Marianne; Talbot, John; Lapworth, Dan; Hart, Alwyn

2016-10-15

A large variety of micro-organic (MO) compounds is used in huge quantities for a range of purposes (e.g. manufacturing, food production, healthcare) and is now being frequently detected in the aquatic environment. Interest in the occurrence of MO contaminants in the terrestrial and aquatic environments continues to grow, as well as in their environmental fate and potential toxicity. However, the contamination of groundwater resources by MOs has a limited evidence base compared to other freshwater resources. Of particular concern are newly 'emerging contaminants' such as pharmaceuticals and lifestyle compounds, particularly those with potential endocrine disrupting properties. While groundwater often has a high degree of protection from pollution due to physical, chemical and biological attenuation processes in the subsurface compared to surface aquatic environments, trace concentrations of a large range of compounds are still detected in groundwater and in some cases may persist for decades due to the long residence times of groundwater systems. This study provides the first national-scale assessment of micro-organic compounds in groundwater in England and Wales. A large set of monitoring data was analysed to determine the relative occurrence and detected concentrations of different groups of compounds and to determine relationships with land-use, aquifer type and groundwater vulnerability. MOs detected including emerging compounds such as caffeine, DEET, bisphenol A, anti-microbial agents and pharmaceuticals as well as a range of legacy contaminants including chlorinated solvents and THMs, petroleum hydrocarbons, pesticides and other industrial compounds. There are clear differences in MOs between land-use types, particularly for urban-industrial and natural land-use. Temporal trends of MO occurrence are assessed but establishing long-term trends is not yet possible. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

Surface-enhanced Raman as a water monitor for warfare agents

NASA Astrophysics Data System (ADS)

Spencer, Kevin M.; Sylvia, James M.; Clauson, Susan L.; Janni, James A.

2002-02-01

The threat of chemical warfare agents being released upon civilian and military personnel continues to escalate. One aspect of chemical preparedness is to analyze and protect the portable water supply for the military. Chemical nerve, blister, and choking agents, as well as biological threats must all be analyzed and low limits of detection must be verified. For chemical agents, this generally means detection down to the low ppb levels. Surface-Enhanced Raman Spectroscopy (SERS) is a spectroscopic technique that can detect trace levels of contaminants directly in the aqueous environment. In this paper, results are presented on the use of SERS to detect chemical and biological agent simulants with an end goal of creating a Joint Service Agent Water Monitor. Detection of cyanide, 2-chloroethyl ethyl sulfide, phosphonates, Gram-positive and Gram-negative bacteria using SERS has been performed and is discussed herein. Aspects of transferring laboratory results to an unattended field instrument are also discussed.

In-situ protein determination to monitor contamination in a centrifugal partition chromatograph.

PubMed

Bouiche, Feriel; Faure, Karine

2017-05-15

Centrifugal partition chromatography (CPC) works with biphasic liquid systems including aqueous two-phase systems. Metallic rotors are able to retain an aqueous stationary phase able to purify proteins. But the adhesion of proteins to solid surface may pose a cross-contamination risk during downstream processes. So it is of utmost importance to ensure the cleanliness of the equipment and detect possible protein contamination in a timely manner. Thereby, a direct method that allows the determination of the effective presence of proteins and the extent of contamination in the metallic CPC rotors was developed. This in-situ method is derived from the Amino Density Estimation by Colorimetric Assay (ADECA) which is based on the affinity of a dye, Coomassie Brillant Blue (CBB), with protonated N + groups of the proteins. In this paper, the ADECA method was developed dynamically, on a 25 mL stainless-steel rotor with various extents of protein contaminations using bovine serum albumin (BSA) as a fouling model. The eluted CBB dye was quantified and found to respond linearly to BSA contamination up to 70 mg injected. Limits of detection and quantification were recorded as 0.9 mg and 3.1 mg, respectively. While the non-specific interactions between the dye and the rotor cannot currently be neglected, this method allows for in situ determination of proteins contamination and should contribute to the development of CPC as a separation tool in protein purification processes. Copyright © 2017 Elsevier Inc. All rights reserved.

Tracking persistent pharmaceutical residues from municipal sewage to drinking water

NASA Astrophysics Data System (ADS)

Heberer, Thomas

2002-09-01

In urban areas such as Berlin (Germany) with high municipal sewage water discharges and low surface water flows there is a potential risk of drinking water contamination by polar organic compounds when groundwater recharge is used in drinking water production. Thus, some pharmaceutically active compounds (PhACs) are not eliminated completely in the municipal sewage treatment plants (STPs) and they are discharged as contaminants into the receiving waters. In terms of several monitoring studies carried out in Berlin between 1996 and 2000, PhACs such as clofibric acid, diclofenac, ibuprofen, propyphenazone, primidone and carbamazepine were detected at individual concentrations up to the μg/l-level in influent and effluent samples from STPs and in all surface water samples collected downstream from the STPs. Under recharge conditions, several compounds were also found at individual concentrations up to 7.3 μg/l in samples collected from groundwater aquifers near to contaminated water courses. A few of the PhACs were also identified at the ng/l-level in Berlin tap water samples.

Synthetic ultraviolet light filtering chemical contamination of coastal waters of Virgin Islands National Park, St. John, U.S. Virgin Islands

USGS Publications Warehouse

Bargar, Timothy A.; Alvarez, David; Garrison, Virginia H.

2015-01-01

Contamination of surface waters by synthetic ultraviolet light (UV) filtering chemicals is a concern for the Virgin Islands National Park (VINP). Discrete water samples were collected from VINP bays to determine UV filter chemical presence in the coastal waters. Spatial distribution and the potential for partitioning between subsurface waters and the sea surface microlayer (SML) were also examined. The UV filter chemicals 4-methylbenzylidene camphor, benzophenone-3, octinoxate, homosalate, and octocrylene were detected at concentrations up to 6073 ng/L (benzophenone-3). Concentrations for benzophenone-3 and homosalate declined exponentially (r2 = 0.86 to 0.98) with distance from the beach. Limited data indicate that some UV filter chemicals may partition to the SML relative to the subsurface waters. Contamination of VINP coastal waters by UV filter chemicals may be a significant issue, but an improved understanding of the temporal and spatial variability of their concentrations would be necessary to better understand the risk they present.

Microplastic contamination in the San Francisco Bay, California, USA.

PubMed

Sutton, Rebecca; Mason, Sherri A; Stanek, Shavonne K; Willis-Norton, Ellen; Wren, Ian F; Box, Carolynn

2016-08-15

Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000particles/km(2), Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution of tributyltin in surface sediments from transitional marine-lagoon system of the south-eastern Baltic Sea, Lithuania.

PubMed

Suzdalev, Sergej; Gulbinskas, Saulius; Blažauskas, Nerijus

2015-02-01

The current research paper presents the results of contamination by tributyltin (TBT) compounds in Klaipėda Port, which is situated in a unique marine-lagoon water interaction zone. One hundred fifty-four surface sediment samples have been taken along the whole transition path from lagoon to the sea and analysed in order to quantify the contamination rate in specific environment of high anthropogenic pressure. The detected TBT concentrations ranged from 1 to 5,200 ng Sn g(-1) of dry weight of sediment. The back-trace of horizontal distribution of TBT-contaminated sediments show obvious increase of tributyltin concentrations closer to port areas dealing with ship repair and places of dry-docking facilities. This is a clear indication that those activities are the main source of contamination in the study area. The estimated correlation of TBT concentration in sediments with total organic carbon and the amount of fine fraction (<0.063 mm) was significant for most of the stations. The TBT concentration in those sites varies from 1 to 100 ng Sn g(-1). This fact indicates that the most intensive accumulation of tributyltin is related to potential contamination source areas (ship repairing, dockyards) due to direct input of hazardous substances into the water.

Utilization of fluorescent microspheres and a green fluorescent protein-marked strain for assessment of microbiological contamination of permafrost and ground ice core samples from the Canadian High Arctic.

PubMed

Juck, D F; Whissell, G; Steven, B; Pollard, W; McKay, C P; Greer, C W; Whyte, L G

2005-02-01

Fluorescent microspheres were applied in a novel fashion during subsurface drilling of permafrost and ground ice in the Canadian High Arctic to monitor the exogenous microbiological contamination of core samples obtained during the drilling process. Prior to each drill run, a concentrated fluorescent microsphere (0.5-microm diameter) solution was applied to the interior surfaces of the drill bit, core catcher, and core tube and allowed to dry. Macroscopic examination in the field demonstrated reliable transfer of the microspheres to core samples, while detailed microscopic examination revealed penetration levels of less than 1 cm from the core exterior. To monitor for microbial contamination during downstream processing of the permafrost and ground ice cores, a Pseudomonas strain expressing the green fluorescent protein (GFP) was painted on the core exterior prior to processing. Contamination of the processed core interiors with the GFP-expressing strain was not detected by culturing the samples or by PCR to detect the gfp marker gene. These methodologies were quick, were easy to apply, and should help to monitor the exogenous microbiological contamination of pristine permafrost and ground ice samples for downstream culture-dependent and culture-independent microbial analyses.

Utilization of Fluorescent Microspheres and a Green Fluorescent Protein-Marked Strain for Assessment of Microbiological Contamination of Permafrost and Ground Ice Core Samples from the Canadian High Arctic

PubMed Central

Juck, D. F.; Whissell, G.; Steven, B.; Pollard, W.; McKay, C. P.; Greer, C. W.; Whyte, L. G.

2005-01-01

Fluorescent microspheres were applied in a novel fashion during subsurface drilling of permafrost and ground ice in the Canadian High Arctic to monitor the exogenous microbiological contamination of core samples obtained during the drilling process. Prior to each drill run, a concentrated fluorescent microsphere (0.5-μm diameter) solution was applied to the interior surfaces of the drill bit, core catcher, and core tube and allowed to dry. Macroscopic examination in the field demonstrated reliable transfer of the microspheres to core samples, while detailed microscopic examination revealed penetration levels of less than 1 cm from the core exterior. To monitor for microbial contamination during downstream processing of the permafrost and ground ice cores, a Pseudomonas strain expressing the green fluorescent protein (GFP) was painted on the core exterior prior to processing. Contamination of the processed core interiors with the GFP-expressing strain was not detected by culturing the samples or by PCR to detect the gfp marker gene. These methodologies were quick, were easy to apply, and should help to monitor the exogenous microbiological contamination of pristine permafrost and ground ice samples for downstream culture-dependent and culture-independent microbial analyses. PMID:15691963

Removal of organic wastewater contaminants in septic systems using advanced treatment technologies

USGS Publications Warehouse

Wilcox, J.D.; Bahr, J.M.; Hedman, C.J.; Hemming, J.D.C.; Barman, M.A.E.; Bradbury, K.R.

2009-01-01

The detection of pharmaceuticals and other organic wastewater contaminants (OWCs) in ground water and surface-water bodies has raised concerns about the possible ecological impacts of these compounds on nontarget organisms. On-site wastewater treatment systems represent a potentially significant route of entry for organic contaminants to the environment. In this study, effluent samples were collected and analyzed from conventional septic systems and from systems using advanced treatment technologies. Six of 13 target compounds were detected in effluent from at least one septic system. Caffeine, paraxanthine, and acetaminophen were the most frequently detected compounds, and estrogenic activity was detected in 14 of 15 systems. The OWC concentrations were significantly lower in effluent after sand filtration (p < 0.01) or aerobic treatment (p < 0.05) as compared with effluent that had not undergone advanced treatment. In general, concentrations in conventional systems were comparable to those measured in previous studies of municipal wastewater treatment plant (WWTP) influent, and concentrations in systems after advanced treatment were comparable to previously measured concentrations in WWTP effluent. These data indicate that septic systems using advanced treatment can reduce OWCs in treated effluent to similar concentrations as municipal WWTPs. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Assessment of soil-gas contamination at building 310 underground storage tank area, Fort Gordon, Georgia, 2010-2011

USGS Publications Warehouse

Guimaraes, Wladmir B.; Falls, W. Fred; Caldwell, Andral W.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

2012-01-01

Soil gas was assessed for contaminants in the building 310 underground storage tank area adjacent to the Dwight D. Eisenhower Army Medical Center at Ft. Gordon, Georgia, from October 2010 to September 2011. The assessment, which also included the detection of organic compounds in soil gas, provides environmental contamination data to Fort Gordon personnel pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The study was conducted by the U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon. Soil-gas samplers were deployed below land surface at 37 locations in the building 310 underground storage tank area. Soil-gas samplers were deployed in a grid pattern near the storage tank area as well as downslope of the tank area in the direction of groundwater flow toward an unnamed tributary to Butler Creek. Total petroleum hydrocarbons were detected in 35 of the 37 soil-gas samplers at levels above the method detection level, and the combined mass of benzene, toluene, ethylbenzene, and total xylenes were detected above their detection levels in 8 of the 37 samplers. In addition, the combined masses of undecane, tridecane, and pentadecane were detected at or above their method detection levels in 9 of the 37 samplers. Other volatile organic compounds detected above their respective method detection levels were chloroform, 1,2,4-trimethylbenzene, and perchloroethylene. In addition, naphthalene, 2-methyl naphthalene, and 1,2,4-trimethylbenzene were detected below the method detection levels, but above the nondetection level.

Rapid detection of single E. coli bacteria using a graphene-based field-effect transistor device.

PubMed

Thakur, Bhawana; Zhou, Guihua; Chang, Jingbo; Pu, Haihui; Jin, Bing; Sui, Xiaoyu; Yuan, Xiaochen; Yang, Ching-Hong; Magruder, Matthew; Chen, Junhong

2018-07-01

Contamination of surface and drinking water due to the presence of Escherichia coli bacteria is a major cause of water-borne disease outbreak. To address unmet challenges for practical pathogen detection in contaminated samples, we report fabrication of thermally reduced graphene oxide-based field-effect transistor (rGO FET) passivated with an ultrathin layer of Al 2 O 3 for real-time detection of E. coli bacteria. The sensor could detect a single E. coli cell within 50 s in a 1 µL sample volume. The ultrathin layer of Al 2 O 3 acted as a barrier between rGO and potential interferents present in the sample. E. coli specific antibodies anchored on gold nanoparticles acted as probes for selective capture of E. coli. The high density of negative charge on the surface of E. coli cells strongly modulates the concentration of majority charge carriers in the rGO monolayer, thereby allowing real-time monitoring of E. coli concentration in a given sample. With a low detection limit of single cell, the FET sensor had a linear range of 1-100 CFU in 1 µL volume of sample (i.e., 10 3 to 10 5 CFU/ mL). The biosensor with good selectivity and rapid detection was further successfully demonstrated for E. coli sensing in river water. The rGO-based FET sensor provides a low cost and label-free approach, and can be mass produced for detection of a broad spectrum of pathogens in water or other liquid media. Copyright © 2018 Elsevier B.V. All rights reserved.

Challenging a bioinformatic tool’s ability to detect microbial contaminants using in silico whole genome sequencing data

PubMed Central

Zook, Justin M.; Morrow, Jayne B.; Lin, Nancy J.

2017-01-01

High sensitivity methods such as next generation sequencing and polymerase chain reaction (PCR) are adversely impacted by organismal and DNA contaminants. Current methods for detecting contaminants in microbial materials (genomic DNA and cultures) are not sensitive enough and require either a known or culturable contaminant. Whole genome sequencing (WGS) is a promising approach for detecting contaminants due to its sensitivity and lack of need for a priori assumptions about the contaminant. Prior to applying WGS, we must first understand its limitations for detecting contaminants and potential for false positives. Herein we demonstrate and characterize a WGS-based approach to detect organismal contaminants using an existing metagenomic taxonomic classification algorithm. Simulated WGS datasets from ten genera as individuals and binary mixtures of eight organisms at varying ratios were analyzed to evaluate the role of contaminant concentration and taxonomy on detection. For the individual genomes the false positive contaminants reported depended on the genus, with Staphylococcus, Escherichia, and Shigella having the highest proportion of false positives. For nearly all binary mixtures the contaminant was detected in the in-silico datasets at the equivalent of 1 in 1,000 cells, though F. tularensis was not detected in any of the simulated contaminant mixtures and Y. pestis was only detected at the equivalent of one in 10 cells. Once a WGS method for detecting contaminants is characterized, it can be applied to evaluate microbial material purity, in efforts to ensure that contaminants are characterized in microbial materials used to validate pathogen detection assays, generate genome assemblies for database submission, and benchmark sequencing methods. PMID:28924496

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Adrian Municipal Well Field site is in Adrian, Nobles County, Minnesota, a city which relies solely on ground water for its municipal water supply. In 1983 the State detected VOC contamination in two of the six wells at the site, and by 1985 the city had replaced the VOC-contaminated wells with two new wells. Subsequent ground water sampling indicated that petroleum releases from underground storage tanks (UST) are sources for soil and ground water contamination. Although ground water contaminant concentrations exceed Federal and State drinking water and surface water standards, no further action will be taken by the Superfundmore » program because the program does not have the authority to address clean up of petroleum releases. EPA will, however, formally transfer the site to its UST program in October 1989 for further action. There are no costs associated with this remedial action.« less

Health assessment for Kaiser Aluminum and Chemical Corporation, Mead, Spokane County, Washington, Region 10. CERCLIS No. WAD000065508. Preliminary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-04-12

The 240-acre Kaiser Aluminum Site is on the National Priorities List. The plant was built in 1942 as an aluminum-reduction facility. Concentrations of cyanide (total) in the river range from 0.011 to 1.7 parts per million (ppm) and free cyanide concentrations ranged from non-detected (ND) to 0.58 ppm. Soils on-site are contaminated with cyanide and fluoride; total cyanide levels range from ND to 985 ppm. The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of exposure to hazardous substances via ingestion of contaminated ground water, dermal absorptionmore » of contaminants found in the surface soils on-site, and inhalation of and dermal contact with reentrained contaminated dust.« less

Assessing the susceptibility to contamination of two aquifer systems used for public water supply in the Modesto and Fresno metropolitan areas, California, 2001 and 2002

USGS Publications Warehouse

Wright, Michael T.; Belitz, Kenneth; Johnson, Tyler D.

2004-01-01

Ground-water samples were collected from 90 active public supply wells in the Fresno and Modesto metropolitan areas as part of the California Aquifer Susceptibility (CAS) program. The CAS program was formed to examine the susceptibility to contamination of aquifers that are tapped by public supply wells to serve the citizens of California. The objectives of the program are twofold: (1) to evaluate the quality of ground water used for public supply using volatile organic compound (VOC) concentrations in ground-water samples and (2) to determine if the occurrence and distribution of low level VOCs in ground water and characteristics, such as land use, can be used to predict aquifer susceptibility to contamination from anthropogenic activities occurring at, or near, land surface. An evaluation was made of the relation between VOC occurrence and the explanatory variables: depth to the top of the uppermost well perforation, land use, relative ground-water age, high nitrate concentrations, density of leaking underground fuel tanks (LUFT), and source of recharge water. VOCs were detected in 92 percent of the wells sampled in Modesto and in 72 percent of the wells sampled in Fresno. Trihalomethanes (THM) and solvents were frequently detected in both study areas. Conversely, the gasoline components?benzene, toluene ethylbenzene, and xylenes (BTEX)?were rarely, if at all, detected, even though LUFTs were scattered throughout both study areas. The rare occurrence of BTEX compounds may be the result of their low solubility and labile nature in the subsurface environment. Samples were analyzed for 85 VOCs; 25 were detected in at least one sample. The concentrations of nearly all VOCs detected were at least an order of magnitude below action levels set by drinking water standards. Concentrations of four VOCs exceeded federal and state maximum contaminant levels (MCL): the solvent trichloroethylene (TCE) and the fumigant 1, 2-dibromo-3-chloropropane (DBCP) in Fresno, and the solvents TCE and tetrachloroethylene (PCE) in Modesto. Chloroform, which is a by product of water disinfection and a constituent used in industrial processes since the 1920s, was the most frequently detected compound, whereas the gasoline oxygenate methyl tert-butyl ether (MTBE), which has been in widespread production and use only since the 1990s, was detected in only 2 percent of the samples. Downward migration of contaminants appears to be a viable pathway of contamination in the unconfined and semi-confined aquifers underlying the Fresno and Modesto study areas. Within the individual study areas, VOCs were detected more frequently and in greater numbers in shallower wells than in deeper wells. Additionally, VOCs were detected more frequently and in greater numbers in Modesto than in Fresno. Wells sampled in Modesto were significantly shallower than the wells sampled in Fresno; the other explanatory variables examined in this report were not significantly different between the two study areas. VOCs occurred more frequently in younger ground water (water recharged after 1952) than in older ground water (water recharged prior to 1952). Additionally, wells withdrawing younger ground water had a higher number of VOCs detected per well than did wells withdrawing older ground water. Younger ground water was at or near the land surface during a period when VOCs came into widespread production and use. Therefore, wells from which younger ground water is withdrawn may be more susceptible to contamination. Of the explanatory variables examined in this study, land use was the best predictor of aquifer susceptibility in the Fresno and Modesto study areas. VOCs were detected more frequently in wells located in heavily urbanized areas. The number of VOCs detected in ground water was positively correlated to the degree of urbanization. VOCs are produced and used primarily in urban land use settings; therefore, aquifers underlying urban areas may be more susceptible to

Surface analysis of anodized aluminum clamps from NASA-LDEF satellite

NASA Technical Reports Server (NTRS)

Grammer, H. L.; Wightman, J. P.; Young, Philip R.

1992-01-01

Surface analysis results of selected anodized aluminum clamps containing black (Z306) and white (A276) paints which received nearly six years of Low Earth Orbit (LEO) exposure on the Long Duration Exposure Facility are reported. Surface analytical techniques, including x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and scanning electron microscopy/energy dispersive analysis by x-ray (SEM/EDAX), showed significant differences in the surface composition of these materials depending upon the position on the LDEF. Differences in the surface composition are attributed to varying amounts of atomic oxygen and vacuum ultraviolet radiation (VUV). Silicon containing compounds were the primary contaminant detected on the materials.

Surface characterization of selected LDEF tray clamps

NASA Technical Reports Server (NTRS)

Cromer, T. F.; Grammer, H. L.; Wightman, J. P.; Young, Philip R.; Slemp, Wayne S.

1993-01-01

The surface characterization of chromic acid anodized 6061-T6 aluminum alloy tray clamps has shown differences in surface chemistry depending upon the position on the Long Duration Exposure Facility (LDEF). Water contact angle results showed no changes in wettability of the tray clamps. The overall surface topography of the control, trailing edge(E3) and leading edge(D9) samples was similar. The thickness of the aluminum oxide layer for all samples determined by Auger depth profiling was less than one micron. X-ray photoelectron spectroscopy (XPS) analysis of the tray clamps showed significant differences in the surface composition. Carbon and silicon containing compounds were the primary contaminants detected.

Potential microbial contamination during sampling of permafrost soil assessed by tracers

NASA Astrophysics Data System (ADS)

Bang-Andreasen, Toke; Schostag, Morten; Priemé, Anders; Elberling, Bo; Jacobsen, Carsten S.

2017-02-01

Drilling and handling of permanently frozen soil cores without microbial contamination is of concern because contamination e.g. from the active layer above may lead to incorrect interpretation of results in experiments investigating potential and actual microbial activity in these low microbial biomass environments. Here, we present an example of how microbial contamination from active layer soil affected analysis of the potentially active microbial community in permafrost soil. We also present the development and use of two tracers: (1) fluorescent plastic microspheres and (2) Pseudomonas putida genetically tagged with Green Fluorescent Protein production to mimic potential microbial contamination of two permafrost cores. A protocol with special emphasis on avoiding microbial contamination was developed and employed to examine how far microbial contamination can penetrate into permafrost cores. The quantity of tracer elements decreased with depth into the permafrost cores, but the tracers were detected as far as 17 mm from the surface of the cores. The results emphasize that caution should be taken to avoid microbial contamination of permafrost cores and that the application of tracers represents a useful tool to assess penetration of potential microbial contamination into permafrost cores.

Potential microbial contamination during sampling of permafrost soil assessed by tracers.

PubMed

Bang-Andreasen, Toke; Schostag, Morten; Priemé, Anders; Elberling, Bo; Jacobsen, Carsten S

2017-02-23

Drilling and handling of permanently frozen soil cores without microbial contamination is of concern because contamination e.g. from the active layer above may lead to incorrect interpretation of results in experiments investigating potential and actual microbial activity in these low microbial biomass environments. Here, we present an example of how microbial contamination from active layer soil affected analysis of the potentially active microbial community in permafrost soil. We also present the development and use of two tracers: (1) fluorescent plastic microspheres and (2) Pseudomonas putida genetically tagged with Green Fluorescent Protein production to mimic potential microbial contamination of two permafrost cores. A protocol with special emphasis on avoiding microbial contamination was developed and employed to examine how far microbial contamination can penetrate into permafrost cores. The quantity of tracer elements decreased with depth into the permafrost cores, but the tracers were detected as far as 17 mm from the surface of the cores. The results emphasize that caution should be taken to avoid microbial contamination of permafrost cores and that the application of tracers represents a useful tool to assess penetration of potential microbial contamination into permafrost cores.

Potential microbial contamination during sampling of permafrost soil assessed by tracers

PubMed Central

Bang-Andreasen, Toke; Schostag, Morten; Priemé, Anders; Elberling, Bo; Jacobsen, Carsten S.

2017-01-01

Drilling and handling of permanently frozen soil cores without microbial contamination is of concern because contamination e.g. from the active layer above may lead to incorrect interpretation of results in experiments investigating potential and actual microbial activity in these low microbial biomass environments. Here, we present an example of how microbial contamination from active layer soil affected analysis of the potentially active microbial community in permafrost soil. We also present the development and use of two tracers: (1) fluorescent plastic microspheres and (2) Pseudomonas putida genetically tagged with Green Fluorescent Protein production to mimic potential microbial contamination of two permafrost cores. A protocol with special emphasis on avoiding microbial contamination was developed and employed to examine how far microbial contamination can penetrate into permafrost cores. The quantity of tracer elements decreased with depth into the permafrost cores, but the tracers were detected as far as 17 mm from the surface of the cores. The results emphasize that caution should be taken to avoid microbial contamination of permafrost cores and that the application of tracers represents a useful tool to assess penetration of potential microbial contamination into permafrost cores. PMID:28230151

Surface cleanliness measurement procedure

DOEpatents

Schroder, Mark Stewart; Woodmansee, Donald Ernest; Beadie, Douglas Frank

2002-01-01

A procedure and tools for quantifying surface cleanliness are described. Cleanliness of a target surface is quantified by wiping a prescribed area of the surface with a flexible, bright white cloth swatch, preferably mounted on a special tool. The cloth picks up a substantial amount of any particulate surface contamination. The amount of contamination is determined by measuring the reflectivity loss of the cloth before and after wiping on the contaminated system and comparing that loss to a previous calibration with similar contamination. In the alternative, a visual comparison of the contaminated cloth to a contamination key provides an indication of the surface cleanliness.

Tools for measuring surface cleanliness

DOEpatents

Schroder, Mark Stewart; Woodmansee, Donald Ernest; Beadie, Douglas Frank

2002-01-01

A procedure and tools for quantifying surface cleanliness are described. Cleanliness of a target surface is quantified by wiping a prescribed area of the surface with a flexible, bright white cloth swatch, preferably mounted on a special tool. The cloth picks up a substantial amount of any particulate surface contamination. The amount of contamination is determined by measuring the reflectivity loss of the cloth before and after wiping on the contaminated system and comparing that loss to a previous calibration with similar contamination. In the alternative, a visual comparison of the contaminated cloth to a contamination key provides an indication of the surface cleanliness.

Design and Practices for Use of Automated Drilling and Sample Handling in MARTE While Minimizing Terrestrial and Cross Contamination

NASA Astrophysics Data System (ADS)

Miller, David P.; Bonaccorsi, Rosalba; Davis, Kiel

2008-10-01

Mars Astrobiology Research and Technology Experiment (MARTE) investigators used an automated drill and sample processing hardware to detect and categorize life-forms found in subsurface rock at Río Tinto, Spain. For the science to be successful, it was necessary for the biomass from other sources -- whether from previously processed samples (cross contamination) or the terrestrial environment (forward contamination) -- to be insignificant. The hardware and practices used in MARTE were designed around this problem. Here, we describe some of the design issues that were faced and classify them into problems that are unique to terrestrial tests versus problems that would also exist for a system that was flown to Mars. Assessment of the biomass at various stages in the sample handling process revealed mixed results; the instrument design seemed to minimize cross contamination, but contamination from the surrounding environment sometimes made its way onto the surface of samples. Techniques used during the MARTE Río Tinto project, such as facing the sample, appear to remove this environmental contamination without introducing significant cross contamination from previous samples.

Design and practices for use of automated drilling and sample handling in MARTE while minimizing terrestrial and cross contamination.

PubMed

Miller, David P; Bonaccorsi, Rosalba; Davis, Kiel

2008-10-01

Mars Astrobiology Research and Technology Experiment (MARTE) investigators used an automated drill and sample processing hardware to detect and categorize life-forms found in subsurface rock at Río Tinto, Spain. For the science to be successful, it was necessary for the biomass from other sources--whether from previously processed samples (cross contamination) or the terrestrial environment (forward contamination)-to be insignificant. The hardware and practices used in MARTE were designed around this problem. Here, we describe some of the design issues that were faced and classify them into problems that are unique to terrestrial tests versus problems that would also exist for a system that was flown to Mars. Assessment of the biomass at various stages in the sample handling process revealed mixed results; the instrument design seemed to minimize cross contamination, but contamination from the surrounding environment sometimes made its way onto the surface of samples. Techniques used during the MARTE Río Tinto project, such as facing the sample, appear to remove this environmental contamination without introducing significant cross contamination from previous samples.

Microbiological contamination in peanut confectionery processing plants.

PubMed

Carminati, J de A; Amorim Neto, D P; Morishita, K N; Takano, L V; Olivier Bernardi, A; Copetti, M V; do Nascimento, M da S

2016-10-01

In order to investigate Enterobacteriaceae, coliforms, Escherichia coli and Salmonella contamination, a survey was conducted at three peanut confectionery processing companies (A, B and C) in Brazil. Samples of different peanut confectionery products (n = 59), peanut raw material (n = 30), manufacturing environment (n = 116) and workers' hand surfaces (n = 12) were analysed. Salmonella and E. coli were not detected in any final product or raw material analysed. Enterobacteriaceae was isolated from 15% of final products. Coliforms were detected in only one sample. Referring to the raw material, six samples showed contamination by Enterobacteriaceae and three samples by coliforms. For the process environment, 19% and 11% of samples presented Enterobacteriaceae and coliforms. Escherichia coli was detected in 5% of samples, and one of these samples tested positive for Salmonella; this strain was serotyping as S. Heidelberg. All food handlers surveyed in Company C showed Enterobacteriaceae and coliforms on their hands. Escherichia coli was isolated from one food worker's hand. The results showed that the manufacturing environment, including food handlers were considered the main sources for possible contamination of peanut confectionery products. This has been the first study to investigate the occurrence of Salmonella and other Enterobacteriaceae throughout peanut confectionery processing lines. The results might be used to assist risk assessment studies and to establish more effective control measures. © 2016 The Society for Applied Microbiology.

Public health assessment for McCormick and Baxter Creosoting Company, Stockton, San Joaquin County, California, Region 9. Cerclis No. CAD009106527. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-04-06

In February 1992, the United State Environmental Protection Agency (USEPA) proposed that the McCormick and Baster Creosoting Company in Stockton, California be listed on the National Priorities List (NPL) because of contamination resulting from a wood preserving plant that operated there from 1942 until 1990. Chemicals used in the preservative solutions included creosote, pentachlorophenol, arsenic, copper, and chromium. Contamination has been detected in the on-site surface soil, subsurface soil, on-site air when the site was in operation, nearby off-site surface, soil, on-sit groundwater, off-site groundwater to a small extent, and perhaps in the fish living in the Old Mormon Slough,more » New Mormon Slough, and the Port of Stockton.« less

Pulse granuloma as a complication following dental trauma in children.

PubMed

Padmanabhan, Makkada Yuvaraj; Aparna, Radhakrishnan; Karthikeyani, Shanmugasundaram; Dinakar, Jayakumar; Manickaraj, Menaka

2013-01-01

Contamination and subsequent retention of foreign bodies within wound surfaces may negatively influence healing following maxillofacial injuries. Larger foreign bodies that produce embedded or impalement injuries of soft tissues are easily detected. However, smaller contaminants, such as sand, gravel, food particles, wood splinters, and glass fibers, may not be easily identified in the initial examination, and their remnants may remain within the injury site even after debridement. Tissue reactions depend on the host response, type of foreign body, and nature of the wound surface. The purposes of this report are to: (1) detail the diagnosis and management of a peripheral pulse granuloma following retention of food particles within gingival sulci during a dental injury; and (2) provide a brief review of the diagnosis of foreign body-induced granulomas following maxillofacial injuries in children.

Natural attenuation in a surface water channel and a coastal aquifer by monitoring presence and removal of indicator bacteria, pathogens and antibiotic resistance gene: model development

NASA Astrophysics Data System (ADS)

Masciopinto, Costantino; Visino, Fabrizio; Luprano, Maria Laura; Levantesi, Caterina; Tandoi, Valter

2015-04-01

The spreading of microbial contamination into the environment, represents a very relevant problem, which leads to an increasing health concern. For this reason, it is important to identify and characterize the extent of natural depuration in water environmental particularly for reducing the presence of faecal contamination indicator bacteria, pathogens and antibiotic resistance genes (ARG). In this study, the presence of the above reported microbial parameters was analyzed in a surface water channel and in a coastal aquifer in southern Italy (Ostuni) southern Italy, both affected by Ostuni municipal treatment plant effluents and by local run-off. Several samples were collected from surface water, flowing in channels, and from wells in our study area. In particular, the water samples were analyzed to detect 7 fecal contamination indicators (E. coli, total coliforms, Clostridium p. spores, somatic coliphages, Enterococci and heterotrophic bacteria), Salmonella spp and the presence of ARGs. The water samples were also tested for chemical constituents. Finally a mathematical model has been developed in order to simulate pathogen migration pathways in the fractured groundwater and corresponding possible mitigation of pathogens in pumping wells.

Effectiveness of Hypochlorous Acid to Reduce the Biofilms on Titanium Alloy Surfaces in Vitro

PubMed Central

Chen, Chun-Ju; Chen, Chun-Cheng; Ding, Shinn-Jyh

2016-01-01

Chemotherapeutic agents have been used as an adjunct to mechanical debridement for peri-implantitis treatment. The present in vitro study evaluated and compared the effectiveness of hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) at eliminating Gram-negative (E. coli and P. gingivalis) and Gram-positive (E. faecalis and S. sanguinis) bacteria. The effect of irrigating volume and exposure time on the antimicrobial efficacy of HOCl was evaluated, and a durability analysis was completed. Live/dead staining, morphology observation, alamarBlue assay, and lipopolysaccharide (LPS) detection were examined on grit-blasted and biofilm-contaminated titanium alloy discs after treatment with the three chemotherapeutic agents. The results indicated that HOCl exhibited better antibacterial efficacy with increasing irrigating volumes. HOCl achieved greater antibacterial efficacy as treatment time was increased. A decrease in antimicrobial effectiveness was observed when HOCl was unsealed and left in contact with the air. All the irrigants showed antibacterial activity and killed the majority of bacteria on the titanium alloy surfaces of biofilm-contaminated implants. Moreover, HOCl significantly lowered the LPS concentration of P. gingivalis when compared with NaOCl and CHX. Thus, a HOCl antiseptic may be effective for cleaning biofilm-contaminated implant surfaces. PMID:27447617

Assessment of shallow ground-water quality in recently urbanized areas of Sacramento, California, 1998

USGS Publications Warehouse

Shelton, Jennifer L.

2005-01-01

Evidence for anthropogenic impact on shallow ground-water quality beneath recently developed urban areas of Sacramento, California, has been observed in the sampling results from 19 monitoring wells in 1998. Eight volatile organic compounds (VOCs), four pesticides, and one pesticide transformation product were detected in low concentrations, and nitrate, as nitrogen, was detected in elevated concentrations; all of these concentrations were below National and State primary and secondary maximum contaminant levels. VOC results from this study are more consistent with the results from urban areas nationwide than from agricultural areas in the Central Valley, indicating that shallow ground-water quality has been impacted by urbanization. VOCs detected may be attributed to either the chlorination of drinking water, such as trichloromethane (chloroform) detected in 16 samples, or to the use of gasoline additives, such as methyl tert-butyl ether (MTBE), detected in 2 samples. Pesticides detected may be attributed to use on household lawns and gardens and rights-of-way, such as atrazine detected in three samples, or to past agricultural practices, and potentially to ground-water/surface-water interactions, such as bentazon detected in one sample from a well adjacent to the Sacramento River and downstream from where bentazon historically was used on rice. Concentrations of nitrate may be attributed to natural sources, animal waste, old septic tanks, and fertilizers used on lawns and gardens or previously used on agricultural crops. Seven sample concentrations of nitrate, as nitrogen, exceeded 3.0 milligrams per liter, a level that may indicate impact from human activities. Ground-water recharge from rainfall or surface-water runoff also may contribute to the concentrations of VOCs and pesticides observed in ground water. Most VOCs and pesticides detected in ground-water samples also were detected in air and surface-water samples collected at sites within or adjacent to the recently developed urban areas. Five arsenic sample concentrations exceeded the U.S. Environmental Protection Agency (USEPA) primary maximum contaminant level (MCL) of 10 milligrams per liter adopted in 2001. Measurements that exceeded USEPA or California Department of Health Services recommended secondary maximum contaminant levels include manganese, iron, chloride, total dissolved solids, and specific conductance. These exceedances are probably a result of natural processes. Variations in stable isotope ratios of hydrogen (2H/1H) and oxygen (18O/16O) may indicate different sources or a mixing of recharge waters to the urban ground water. These variations also may indicate recharge directly from surface water in one well adjacent to the Sacramento River. Tritium concentrations indicate that most shallow ground water has been recharged since the mid-1950s, and tritium/helium-3 age dates suggest that recharge has occurred in the last 2 to 30 years in some areas. In areas where water table depths exceed 20 meters and wells are deeper, ground-water recharge may have occurred prior to 1950, but low concentrations of pesticides and VOCs detected in these deeper wells indicate a mixing of younger and older waters. Overall, the recently urbanized areas can be divided into two groups. One group contains wells where few VOCs and pesticides were detected, nitrate mostly was not detected, and National and State maximum contaminant levels, including the USEPA MCL for arsenic, were exceeded; these wells are adjacent to rivers and generally are characterized by younger water, shallow (1 to 4 meters) water table, chemically reducing conditions, finer grained sediments, and higher organics in the soils. In contrast, the other group contains wells where more VOCs, pesticides, and elevated nitrate concentrations were detected; these wells are farther from rivers and are generally characterized by a mixture of young and old waters, intermediate to deep (7 to 35 meters) wate

Analysis of emerging contaminants in water and solid samples using high resolution mass spectrometry with a Q Exactive orbital ion trap and estrogenic activity with YES-assay.

PubMed

Comtois-Marotte, Simon; Chappuis, Thomas; Vo Duy, Sung; Gilbert, Nicolas; Lajeunesse, André; Taktek, Salma; Desrosiers, Mélanie; Veilleux, Éloïse; Sauvé, Sébastien

2017-01-01

Trace emerging contaminants (ECs) occur in both waste and surface waters that are rich in particulates that have been found to sorb several organic contaminants. An analytical method based on off-line solid-phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS) analysis was developed for the detection and quantification of 31 ECs from surface water, wastewater, suspended particulate matter (SPM) as well as sediments. Lyophilized sediments and air-dried SPM were subjected to ultrasonic extraction. Water samples and extracts were then concentrated and cleaned-up by off-line SPE. Quantification was realized using a Q Exactive mass spectrometer in both full scan (FS) and MS 2 modes. These two modes were optimized and compared to determine which one was the most suitable for each matrix studied. Yeast estrogen screen assay (YES-assay) adapted from the direct measurement of estrogenic activity without sample extraction was tested on filtered wastewater samples. An endocrine disrupting effect was detected in all effluent samples analyzed with estradiol equivalent concentrations ranging from 4.4 to 720 ng eq E2 L -1 for the WWTP-1 and 6.5-42 ng eq E2 L -1 for the WWTP-2. The analytical methods were also applied on six samples of surface water, the corresponding SPM, the sediments and thirty-nine effluent samples from two wastewater treatment plants (WWTPs) sampled over a period of five months (February to June 2014). Copyright © 2016 Elsevier Ltd. All rights reserved.

A genetic inventory of spacecraft and associated surfaces.

PubMed

La Duc, Myron T; Venkateswaran, Kasthuri; Conley, Catharine A

2014-01-01

Terrestrial organisms or other contaminants that are transported to Mars could interfere with efforts to study the potential for indigenous martian life. Similarly, contaminants that make the round-trip to Mars and back to Earth could compromise the ability to discriminate an authentic martian biosignature from a terrestrial organism. For this reason, it is important to develop a comprehensive inventory of microbes that are present on spacecraft to avoid interpreting their traces as authentic extraterrestrial biosignatures. Culture-based methods are currently used by NASA to assess spacecraft cleanliness but deliberately detect only a very small subset of total organisms present. The National Research Council has recommended that molecular (DNA)-based identification techniques should be developed as one aspect of managing the risk that terrestrial contamination could interfere with detection of life on (or returned from) Mars. The current understanding of the microbial diversity associated with spacecraft and clean room surfaces is expanding, but the capability to generate a comprehensive inventory of the microbial populations present on spacecraft outbound from Earth would address multiple considerations in planetary protection, relevant to both robotic and human missions. To this end, a 6-year genetic inventory study was undertaken by a NASA/JPL team. It was completed in 2012 and included delivery of a publicly available comprehensive final report. The genetic inventory study team evaluated the utility of three analytical technologies (conventional cloning techniques, PhyloChip DNA microarrays, and 454 tag-pyrosequencing) and combined them with a systematic methodology to collect, process, and archive nucleic acids as the first steps in assessing the phylogenetic breadth of microorganisms on spacecraft and associated surfaces.

Influence of Blood Contamination on Bond Strength of a Self-Etching System

PubMed Central

de Carvalho Mendonça, Ellen Cristina; Vieira, Samuel Nilo; Kawaguchi, Fernando Aparecido; Powers, John; Matos, Adriana Bona

2010-01-01

Objectives: To detect the influence of blood contamination (BC) on the bond strength (BS) of a self-etching bonding system (SES) to enamel and dentine. Methods: 25 human molars were longitudinally sectioned on the mesio-distal axis in order to obtain 50 specimens, which were embedded in acrylic resin. At first, the specimens were ground to expose a flat surface of enamel, and a bond strength test was performed. Afterwards, the samples were ground again in order to obtain a flat surface of dentine. Ten groups (total: n=100) were assigned according to substrate (enamel and dentine), step in the bonding sequence when contamination occurred (before the acidic primer and after the bonding resin), and contamination treatment (dry or rinse and dry procedure). Fresh human blood was introduced either before or after SES application (Clearfil SE Bond) and treated with air drying, or by rinsing and drying following application. Composite resin (Filtek Z-250,3M ESPE) was applied as inverted, truncated cured cones that were debonded in tension. Results: The mean tensile BS values (MPa) for enamel/dentine were 19.4/23.0 and 17.1/10.0 for rinse-and-dry treatment (contamination before and after SES, respectively); while the measurements for the dry treatment, 16.2/23.3 and 0.0/0.0 contamination before and after SES, respectively. Conclusions: It was determined that blood contamination impaired adhesion to enamel and dentine when it occurred after bond light curing. Among the tested contamination treatments, the rinse-and-dry treatment produced the highest bond strength with BC after SES application, but it was not sufficient to recover the BS in the contamination-free group. PMID:20613916

In Situ Biological Contamination Studies of the Moon: Implications for Planetary Protection and Life Detection Missions

NASA Technical Reports Server (NTRS)

Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Williams, David R.; Kminek, Gerhard; Rummel, John D.

2010-01-01

NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moan, and future human exploration of Mars and other destinations, including possibly asteroids. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require careful operations, and that all systems be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there a different planetary protection category for human missions, although preliminary C SPAR policy guidelines for human missions to Mars have been developed. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future: Mars surface exploration plans for a human mission to Mars.

DNA decontamination of fingerprint brushes.

PubMed

Szkuta, Bianca; Oorschot, Roland A H van; Ballantyne, Kaye N

2017-08-01

Genetic profiling of DNA collected from fingerprints that have been exposed to various enhancement techniques is routine in many forensic laboratories. As a result of direct contact with fingermark residues during treatment, there is concern around the DNA contamination risk of dusting fingermarks with fingerprint brushes. Previous studies have demonstrated the potential for cross-contamination between evidentiary items through various mechanisms, highlighting the risk of using the same fingerprint brush to powder multiple surfaces within and between crime-scenes. Experiments were performed to assess the contamination risk of reused fingerprint brushes through the transfer of dried saliva and skin deposits from and to glass surfaces with new unused squirrel hair and fiberglass brushes. Additional new unused brushes and brushes previously used in casework were also tested for their ability to contaminate samples. In addition, the ability to eradicate DNA from used squirrel hair and fiberglass fingerprint brushes was assessed using a 1% sodium hypochlorite solution and a 5% solution of a commercially available alternative, Virkon. DNA profiling results from surfaces contacted by treated and untreated brushes were compared to determine the effectiveness of the devised cleaning protocol. Brush durability was also assessed over multiple wash/rinse/dry cycles with both agents. Varying amounts of DNA-containing material were collected and transferred by squirrel hair and fiberglass brushes, with detectability on the secondary surface dependent on the biological nature of the material being transferred. The impact of DNA contamination from dirty fingerprint brushes was most apparent in simulations involving the transfer of dried saliva and brushes previously used in casework, while minimal transfer of touch DNA was observed. Alarmingly, large quantities of DNA were found to reside on new unused squirrel hair brushes, while no DNA was detected on new unused fiberglass brushes or brushes sold as DNA-free. Squirrel hair brushes were easily and effectively cleaned with both hypochlorite and Virkon, with no evidence of DNA transfer between exhibits by treated brushes. Brushes were still deemed useable after multiple cleaning cycles with either agent. In contrast, fiberglass bristles became tangled and matted when wet and could not be cleaned effectively using either method. It is recommended they are disposed of following use. Each laboratory should consider their current circumstances before adapting a cleaning method. The implementation of a program to monitor the effectiveness of the cleaning regime is also advised. Copyright © 2017 Elsevier B.V. All rights reserved.

Sampling and Homogenization Strategies Significantly Influence the Detection of Foodborne Pathogens in Meat.

PubMed

Rohde, Alexander; Hammerl, Jens Andre; Appel, Bernd; Dieckmann, Ralf; Al Dahouk, Sascha

2015-01-01

Efficient preparation of food samples, comprising sampling and homogenization, for microbiological testing is an essential, yet largely neglected, component of foodstuff control. Salmonella enterica spiked chicken breasts were used as a surface contamination model whereas salami and meat paste acted as models of inner-matrix contamination. A systematic comparison of different homogenization approaches, namely, stomaching, sonication, and milling by FastPrep-24 or SpeedMill, revealed that for surface contamination a broad range of sample pretreatment steps is applicable and loss of culturability due to the homogenization procedure is marginal. In contrast, for inner-matrix contamination long treatments up to 8 min are required and only FastPrep-24 as a large-volume milling device produced consistently good recovery rates. In addition, sampling of different regions of the spiked sausages showed that pathogens are not necessarily homogenously distributed throughout the entire matrix. Instead, in meat paste the core region contained considerably more pathogens compared to the rim, whereas in the salamis the distribution was more even with an increased concentration within the intermediate region of the sausages. Our results indicate that sampling and homogenization as integral parts of food microbiology and monitoring deserve more attention to further improve food safety.

Sampling and Homogenization Strategies Significantly Influence the Detection of Foodborne Pathogens in Meat

PubMed Central

Rohde, Alexander; Hammerl, Jens Andre; Appel, Bernd; Dieckmann, Ralf; Al Dahouk, Sascha

2015-01-01

Efficient preparation of food samples, comprising sampling and homogenization, for microbiological testing is an essential, yet largely neglected, component of foodstuff control. Salmonella enterica spiked chicken breasts were used as a surface contamination model whereas salami and meat paste acted as models of inner-matrix contamination. A systematic comparison of different homogenization approaches, namely, stomaching, sonication, and milling by FastPrep-24 or SpeedMill, revealed that for surface contamination a broad range of sample pretreatment steps is applicable and loss of culturability due to the homogenization procedure is marginal. In contrast, for inner-matrix contamination long treatments up to 8 min are required and only FastPrep-24 as a large-volume milling device produced consistently good recovery rates. In addition, sampling of different regions of the spiked sausages showed that pathogens are not necessarily homogenously distributed throughout the entire matrix. Instead, in meat paste the core region contained considerably more pathogens compared to the rim, whereas in the salamis the distribution was more even with an increased concentration within the intermediate region of the sausages. Our results indicate that sampling and homogenization as integral parts of food microbiology and monitoring deserve more attention to further improve food safety. PMID:26539462

Microbiological quality and safe handling of enteral diets in a hospital in Minas Gerais, Brazil.

PubMed

Pinto, Raquel Oliveira Medrado; Correia, Eliznara Fernades; Pereira, Keyla Carvalho; Costa Sobrinho, Paulo de Souza; da Silva, Daniele Ferreira

2015-06-01

Contamination of enteral diets represents a high risk of compromising the patient's medical condition. To assess the microbiological quality and aseptic conditions in the preparation and administration of handmade and industrialized enteral diets offered in a hospital in the Valley of Jequitinhonha, MG, Brazil, we performed a microbiological analysis of 50 samples of diets and 27 samples of surfaces, utensils, and water used in the preparation of the diets. In addition, we assessed the good handling practices of enteral diets according to the requirements specified by the Brazilian legislation. Both kinds of enteral diets showed contamination by coliforms and Pseudomonas spp. No sample was positive for Staphylococcus aureus and Salmonella spp. On the other hand, Listeria spp. was detected in only one sample of handmade diets. Contamination was significantly higher in the handmade preparations (p < 0.05). Nonconformities were detected with respect to good handling practices, which may compromise the diet safety. The results indicate that the sanitary quality of the enteral diets is unsatisfactory, especially handmade diets. Contamination by Pseudomonas spp. is significant because it is often involved in infection episodes. With regard to aseptic practices, it was observed the need of implementing new procedures for handling enteral diets.

Elemental analyses of hypervelocity micro-particle impact sites on interplanetary dust experiment sensor surfaces

NASA Technical Reports Server (NTRS)

Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. R.; Wortman, Jim J.

1992-01-01

The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity micro-particles that struck the active sensors with enough energy to breakdown the 0.4 to 1.0 micron thick SiO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. These discharge features, which include 50 micron diameter areas where the aluminum top layer has been vaporized, facilitate the location of the impacts. The high purity Al-SiO2-Si substrates allow detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) is used to create two-dimensional elemental ion intensity maps of micro-particle impact sites on the IDE sensors. The element intensities in the central craters of the impacts are corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results are used to classify the particles' origins as 'manmade', 'natural' or 'indeterminate'. The last classification results from the presence of too little impactor residue (a frequent occurrence on leading edge impacts), analytical interference from high background contamination, the lack of information on silicon residue, the limited usefulness of data on aluminum in the central craters, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters, of these features. A total of 35 impacts on leading edge sensors and 22 impacts on trailing edge sensors were analyzed.

Determination of micro-organic contaminants in groundwater (Maribor, Slovenia).

PubMed

Koroša, A; Auersperger, P; Mali, N

2016-11-15

Micro-organic (MO) contaminants in groundwater can have adverse effects on both the environment and on human health. They enter the natural environment as a result of various processes, their presence in groundwater is the result of current anthropogenic activity and pollution loads from the past. A study on the occurrence and concentrations levels of selected contaminants in water was performed in the city of Maribor, Slovenia. A total of 56 groundwater and 4 surface water samples were collected in together four rounds in different hydrogeological periods (dry and wet seasons), and a total of 13 selected contaminants were analysed in this study. Carbamazepine, propyphenazone, caffeine, 2-methyl-2H-benzotriazole (2-MBT) and 2.4-dimethyl-2H-benzotriazole (2.4-DMBT) were determined as indicators of urban pollution, while pesticides and their metabolites (atrazine, desethylatrazine, deisopropylatrazine, terbuthylazine, desethylterbuthylazine, metolachlor, simazine, propazine) were mainly defined as indicators of crop production. All of the selected MO contaminants were detected both in the aquifer and Drava River. The most frequently detected MO compounds in groundwater were desethylatrazine (frequency of detection 98.2%; max. concentration 103.0ngL(-1)), atrazine (94.6%; 229ngL(-1)), 2.4-DMBT (92.9%; 273ngL(-1)), carbamazepine (80.4%; 88.00ngL(-1)), desethylterbuthylazine (76.8%; 7.0ngL(-1)) and simazine (76.8%; 29.6ngL(-1)), whereas propyphenazone (14.3%; 10.7ngL(-1)) was the least frequently detected. Detected MO concentrations in the study were compared with results published elsewhere around the world. Concentrations in groundwater indicate specific land use in their recharge areas. On the basis of correlations and the spatial distribution of selected MOs, groundwater origin for every sampling point was determined. Sampling sites were divided into three different groups for which indicative groundwater quality properties were defined. Copyright © 2016 Elsevier B.V. All rights reserved.

77 FR 58804 - Testing of Product Samples for Listeria monocytogenes: Changes in Procedures

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-24

... risk-based program designed to detect L. monocytogenes contamination from three types of samples: Food.... An IVT, similar to a RLm, is designed to analyze three types of samples: food-contact surfaces..., Pouillot R, et al. A comparative risk assessment for Listeria monocytogenes in prepackaged versus retail...

Screening for contaminants of emerging concern in Northern Colorado Plateau Network waters: 2015 surface-water data

USGS Publications Warehouse

Weissinger, R; Battaglin, William A.; Bradley, Paul M.

2016-01-01

Patterns of detections at other sampling locations will be explored in future reports. This is an interim report. Limited sampling will continue in 2016 at selected sites in coordination with the USGS. A final report is expected upon completion of the USGS project in 2017.

Detection of Campylobacter in 100 commercial flocks - evaluation of plating media and filtration method

USDA-ARS?s Scientific Manuscript database

Campylobacter is a natural member of the gut microflora in many commercial broilers and as such can become a contaminant on edible surfaces during processing. Culturing gut contents or feces can be a means to determine flock status prior to live-haul. The wide variety of non-Campylobacter backgrou...

Rapid Screening Assay for the Detection of Nivalenol and Deoxynivalenol using Monoclonal Antibody and Surface Plasmon Resonance

USDA-ARS?s Scientific Manuscript database

Nivalenol (NIV) and Deoxynivalenol (DON) are trichothecene mycotoxins produced by Fusarium spp that contaminate mainly cereal crops, such as wheat, barley, and maize. These mycotoxins are serious health hazards to human and domestic animals. The study reports a rapid screening method of NIV and DO...

Evaluation of filter-plating methods for simplified detection of Campylobacter associated with broiler cecal samples

USDA-ARS?s Scientific Manuscript database

Introduction: Campylobacter is natural member of the gut microflora in many commercial broilers and as such can become a contaminant on edible surfaces during processing. Culturing gut contents or feces can be a means to determine flock status prior to live-haul. However, the wide variety of non...

49 CFR 177.843 - Contamination of vehicles.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) or § 173.443(c) of this subchapter must be surveyed with radiation detection instruments after each use. A vehicle may not be returned to service until the radiation dose rate at every accessible... if a survey of the interior surface shows that the radiation dose rate does not exceed 0.1 mSv per...

49 CFR 177.843 - Contamination of vehicles.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) or § 173.443(c) of this subchapter must be surveyed with radiation detection instruments after each use. A vehicle may not be returned to service until the radiation dose rate at every accessible... if a survey of the interior surface shows that the radiation dose rate does not exceed 0.1 mSv per...

49 CFR 177.843 - Contamination of vehicles.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) or § 173.443(c) of this subchapter must be surveyed with radiation detection instruments after each use. A vehicle may not be returned to service until the radiation dose rate at every accessible... if a survey of the interior surface shows that the radiation dose rate does not exceed 0.1 mSv per...

Decontaminating the DOE-STD-3013 Inner Container to Meet 10-CFR-835 Appendix D Requirements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, H.E.; Nelson, T.O.; Rivera, Y.M.

The United States Department of Energy (DOE) has published a standard that specifies the criteria for preparation and packaging of plutonium metals and oxides for safe long-term storage (DOE-STD-3013-96). This standard is followed for the packaging of materials resulting from the disassembly of nuclear weapons at Los Alamos National Laboratory under the Advanced Retirement and Integrated Extraction System (ARIES) project. Declassified plutonium metal or oxide material from the ARES project is packaged into doubly contained and welded type 304L stainless steel containers that comply with the DOE standard. The 3013-96 standard describes requirements for maximum contamination limits on the outermore » surface of the sealed inner container. These limits are 500 dpm per 100 cm2 for direct measurements and 20 dpm per 100 cm2 for removable contamination. For containers filled, welded, and handled inside a highly contaminated glovebox line, these limits are difficult to obtain. Simple handling within the line is demonstrated to contaminate surfaces from 10,000 to 10,000,000 dpm alpha per 100 cm2. To routinely achieve contamination levels below the maximum contamination levels specified by the 3013-96 standard within a processing operation, a decontamination step must be included. In the ARIES line, this decontamination step is an electrolytic process that produces a controlled uniform etch of the container surfaces. Decontamination of the 3013-96 compliant ARIES inner container is well demonstrated. Within 30 to 50 minutes electrolysis time, tixed contamination is reduced to hundreds of dpm generally occurring only at electrode contact points and welds. Removable contamination is routinely brought to non-detectable levels. The total process time for the cycle (includes electrolysis, rinse, and dry stages) is on the order of 1.5 to 2 hours per container. The ARIES inner container decontamination system highly automated and consists of a plumbing loop, electronic controls and process monitors, and a decontamination chamber or "fixture". The tixture is situated like an air lock between a contaminated and an uncontaminated section of a processing glovebox. The welded and leak tested container is placed into the fixture through a door on the contaminated side and the electrolysis process is run, including rinse and dry cycles. The container is then removed through a second door into the uncontaminated side where it is monitored for surface alpha contamination, leak checked, and reweighed.« less

Occurrence of Antibiotics in Surface and Groundwater of a Drinking Water Catchment Area in Germany.

PubMed

Burke, Victoria; Richter, Doreen; Greskowiak, Janek; Mehrtens, Anne; Schulz, Lena; Massmann, Gudrun

2016-07-01

The contamination of the aquatic environment with organic micropollutants, such as veterinary pharmaceuticals, has become an increasingly serious problem and has aroused attention in the course of the last decades. This study presents a screening for a series of veterinary antibiotics, potentially introduced by the application of liquid manure, in ground- and surface water of a drinking water catchment in Lower Saxony, Germany. Of the 26 compounds analyzed, eight, including sulfadiazine, sulfapyridine, sulfamethoxazole, trimethoprim, dehydrato-erythromycin, sulfadimidine, tylosin, and tetracycline were detected in surface water samples. Trimethoprim was detected in 11 out of 15 shallow groundwater samples, indicating its high environmental relevance. Column sorption experiments conducted on trimethoprim show a comparatively moderate sorption affinity to sandy aquifer material with a retardation coefficient of 5.7.

Monitoring of selected priority and emerging contaminants in the Guadalquivir River and other related surface waters in the province of Jaén, South East Spain.

PubMed

Robles-Molina, José; Gilbert-López, Bienvenida; García-Reyes, Juan F; Molina-Díaz, Antonio

2014-05-01

The province of Jaén counts with four natural parks, numerous rivers, reservoirs and wetlands; moreover, it is probably the region with higher olive oil production in the world, which makes this zone a proper target to be studied based on the European Water Framework Directive 2000/60/CE. The aim of this survey is to monitor a total number of 373 compounds belonging to different families (pesticides, PAHs, nitrosamines, drugs of abuse, pharmaceuticals and life-style compounds) in surface waters located at different points of the province of Jaén. Among these compounds some priority organic substances (regulated by the EU Directive 2008/105/EC) and pollutants of emerging concern (not regulated yet) can be found. A liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) method covering 340 compounds was developed and applied, together with a gas chromatography triple-quadrupole mass spectrometry (GC-MS/MS) method which enabled the analysis of 63 organic contaminants (30 of these compounds are analyzed by LC-TOFMS as well). From April 2009 to November 2010 a total of 83 surface water samples were collected (rivers, reservoirs and wetlands). In this period numerous organic contaminants were detected, most of them at the ng L(-1) level. The most frequently priority substances found were chlorpyrifos ethyl, diuron and hexachlorobenzene. Within the other groups, the most frequently detected compounds were: terbuthylazine, oxyfluorfen, desethyl terbuthylazine, diphenylamine (pesticide family); fluorene, phenanthrene, pyrene (PAHs group), codeine, paracetamol (pharmaceuticals compounds) and caffeine, nicotine (life-style compounds). As is could be expected, the total concentration of emerging contaminants is distinctly larger than that of priority pollutants, highlighting the importance of continuing with the study of their presence, fate and effects in aquatic environments. However, concentration levels (at the ng per liter level) are low in general for both kinds of contaminants which minimizes the possible harmful effect on the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Identifying fecal sources in a selected catchment reach using multiple source-tracking tools

USGS Publications Warehouse

Vogel, J.R.; Stoeckel, D.M.; Lamendella, R.; Zelt, R.B.; Santo, Domingo J.W.; Walker, S.R.; Oerther, D.B.

2007-01-01

Given known limitations of current microbial source-tracking (MST) tools, emphasis on small, simple study areas may enhance interpretations of fecal contamination sources in streams. In this study, three MST tools - Escherichia coli repetitive element polymerase chain reaction (rep-PCR), coliphage typing, and Bacteroidales 16S rDNA host-associated markers - were evaluated in a selected reach of Plum Creek in sooth-central Nebraska. Water-quality samples were collected from six sites. One reach was selected for MST evaluation based on observed patterns of E. coli contamination. Despite high E. coli concentrations, coliphages were detected only once among water samples, precluding their use as a MST tool in this setting. Rep-PCR classification of E. coli isolates from both water and sediment samples supported the hypothesis that cattle and wildlife were dominant sources of fecal contamination, with minor contributions by horses and humans. Conversely, neither ruminant nor human sources were detected by Bacteroidales markers in most water samples. In bed sediment, ruminant- and human-associated Bacteroidales markers were detected throughout the interval from 0 to 0.3 m, with detections independent of E. coli concentrations in the sediment. Although results by E. coli-based and Bacteroidales-based MST methods led to similar interpretations, detection of Bacteroidales markers in sediment more commonly than in water indicates that different tools to track fecal contamination (in this case, tools based on Bacteroidales DNA and E. coli isolates) may have varying relevance to the more specific goal of tracking the sources of E. coli in watersheds. This is the first report of simultaneous, toolbox approach application of a library-based and marker-based MST analyses to lowing surface water. ?? ASA, CSSA, SSSA.

The effect of contaminant on skid resistance of pavement surface

NASA Astrophysics Data System (ADS)

Lubis, A. S.; Muis, Z. A.; Gultom, E. M.

2018-03-01

Skid resistance of the pavement surface is the force generated by the movement of the wheels of the vehicle on the surface of the pavement. Contaminants are materials that cover the surface of the pavement affecting the skid resistance of the pavement surface. The contaminant acts as a coating interface or direct contact of the pavement surface with the wheels of the vehicle which can cause adverse effects, such as the decreasing value of skid resistance of the pavement surface. This study aims to analyze the effect of some types of contaminants on skid resistance of pavement surfaces. The contaminants that used in this study were water, sand, salt, and lubricating oil. The study was conducted by direct testing on two types of pavement: flexible pavement and rigid pavement. The measurements of the skid resistance were made using the British Pendulum Tester with British Pendulum Number for two conditions: before and after the pavement surface was covered with contaminants. The results showed that there was a contaminant effect on skid resistance of pavement surface. Skid resistance of pavement surfaces decreased after the contaminants were covered in water, sand, salt, and lubricant by 20.1%, 22.8%, 37.1% and 50.5% respectively.

Environmental setting, water quality, and ecological indicators of surface-water quality in the Mermentau River Basin, southwestern Louisiana, 1998-2001

USGS Publications Warehouse

Skrobialowski, Stanley C.; Mize, Scott V.; Demcheck, Dennis K.

2004-01-01

The U.S. Geological Survey collected data from 29 wells and 24 surface-water sites in the Mermentau River Basin, 1998-2001, to better understand ground-water and surface-water quality; aquatic invertebrate communities; and habitat conditions, in relation to land use. This study was apart of the National Water-Quality Assessment Program, which was designed to assess water quality as it relates to various land uses. Water-quality data were evaluated with criteria established for the protection of drinking water and aquatic life, and bed-sediment data were compared to aquatic life criteria. Water-quality and ecological data were analyzed statistically in relation to drainage area and agricultural land-use integrity. Concentrations of nutrients and major inorganic ions in ground water and surface water generally were highest in the southeastern part of the study area where soils contain thick loess deposits. Peak concentrations of nutrients in surface water occurred March-may at two sites with high agricultural intensity; the lowest concentrations occurred August-January. The greatest potential for eutrophic conditions in surface water, based on nutrient concentrations, existed March-May, at about the same time or shortly after ricefields were drained. Secondary Maximum Contaminant Levels established by the U.S. Environmental Protection Agency (USEPA) were exceeded for sulfate, chloride, iron, or manganese in samples from 20 wells, and for iron or manganese in samples from all surface-water sites. Fewer pesticides were detected in ground water than in surface water. In 11 of of the 29 wells sampled, at least one pesticide or pesticide degradation product was detected. The most frequently detected pesticides or pesticide degradation products in ground water were the herbicides benzaton and atrazine. Concentrations of 47 pesticides and degradation products were detected in surface water. At least 3 pesticides were detected in all surface-water samples. In 72 percent of the samples at least 5 hydrophilic pesticides were detected, and in more than 70 percent of the samples at least 3 hydrophobic pesticides were detected. Although atrazine concentrations in three samples collected in the spring exceeded 3 micrograms per liter, the USEPA Maximum Contaminant Level of 3 micrograms per liter was not exceeded because it is based on an annual average of quarterly samples. Concentrations larger than 3.0 micrograms per liter were not detected in samples collected during other times of the year. Tebuthiuron was detected at all surface-water sites; the largest concentration (6.33 micrograms per liter) was detected at a site on Bayou des Cannes, and was the only detection that exceeded the criterion (1.6 micrograms per liter) for the protection of aquatic life. Malathion was detected at 16 surface-water sites; the largest concentration (0.113 micrograms per liter) was detected at a site on Bayou Lacassine and was the only detection that exceeded the criterion (0.1 micrograms per liter) for the protection of aquatic life. Concentrations of fipronil exceeded numeric targets for acute total maximum daily loads (2.3 micrograms per liter) at 3 sites and chronic total maximum daily loads (4.6 micrograms per liter) at 14 sites. Maximum pesticide concentrations in surface water usually occurred in the spring at about the same time or shortly after ricefields were drained. Concentrations of DDE in bed sediment at two sites exceeded interim freshwater sediment quality guidelines for the protection of aquatic life. Fipronil sulfide and desulfinylpronil were detected at all 17 sites from which bed-sediment samples were collected, but there are no current (2002) guidelines with which to evaluate the environmental effects of fipronil and degradation products. Two methods were used to group the ecological data-collection sites: (1) Sites were grouped before data collection (according to the study design) using drainage area

Measurements on low level plutonium sources using Rad Elec Electret Ion Chambers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levinskas, D.; Teagarden, J.; Wilkes, E.

1998-11-01

This is a technique for measuring gross alpha particle emission from interior contaminated surfaces. The technique utilizes electret ionization chambers (EICs), which consist of a charged Teflon plate (the electret) and an electrically-conductive plastic chamber of 145 ml volume. To measure very low levels of alpha contamination, the EIC is left in place on the surface to be measured for about 48 hours. The change in the surface charge of the electret is a measure of the ionization during the measurement period. The rate of change of the charge is converted into an activity using an appropriate calibration factor. Thismore » system has the ability to make accurate gross alpha contamination measurements while being subject to a high airborne radon concentration, such as might occur in certain buildings or during an atmospheric inversion. Previous studies of the effectiveness of these EIC`s focused on levels of alpha contamination much higher than is allowed for unrestricted release of material at the Rocky Flats Environmental Technology Site (RFETS). This study evaluated the performance of EIC`s at levels from 100 disintegrations per minute (dpm) per 100 cm{sup 2} to below 20 dpm per 100 cm{sup 2} (all measurements are referenced to a 4{pi} geometry). The EIC`s were found to be within 5% accuracy, as compared to a gas flow proportional counter calibrated with a NIST-traceable source. Test results indicate that the EIC, left in place for 48 hours, can detect alpha contamination as low as 6.4 {+-} 3.0 dpm/100 cm{sup 2} to a 95% confidence level.« less

Method for remote detection of trace contaminants

DOEpatents

Simonson, Robert J.; Hance, Bradley G.

2003-09-09

A method for remote detection of trace contaminants in a target area comprises applying sensor particles that preconcentrate the trace contaminant to the target area and detecting the contaminant-sensitive fluorescence from the sensor particles. The sensor particles can have contaminant-sensitive and contaminant-insensitive fluorescent compounds to enable the determination of the amount of trace contaminant present in the target are by relative comparison of the emission of the fluorescent compounds by a local or remote fluorescence detector. The method can be used to remotely detect buried minefields.

Fungal contamination assessment in Portuguese elderly care centers.

PubMed

Viegas, C; Almeida-Silva, M; Gomes, A Quintal; Wolterbeek, H T; Almeida, S M

2014-01-01

Individuals spend 80-90% of their day indoors and elderly subjects are likely to spend even a greater amount of time indoors. Thus, indoor air pollutants such as bioaerosols may exert a significant impact on this age group. The aim of this study was to characterize fungal contamination within Portuguese elderly care centers. Fungi were measured using conventional as well as molecular methods in bedrooms, living rooms, canteens, storage areas, and outdoors. Bioaerosols were evaluated before and after the microenvironments' occupancy in order to understand the role played by occupancy in fungal contamination. Fungal load results varied from 32 colony-forming units CFU m(-3) in bedrooms to 228 CFU m(-3) in storage areas. Penicillium sp. was the most frequently isolated (38.1%), followed by Aspergillus sp. (16.3%) and Chrysonilia sp. (4.2%). With respect to Aspergillus genus, three different fungal species in indoor air were detected, with A. candidus (62.5%) the most prevalent. On surfaces, 40 different fungal species were isolated and the most frequent was Penicillium sp. (22.2%), followed by Aspergillus sp. (17.3%). Real-time polymerase chain reaction did not detect the presence of A. fumigatus complex. Species from Penicillium and Aspergillus genera were the most abundant in air and surfaces. The species A. fumigatus was present in 12.5% of all indoor microenvironments assessed. The living room was the indoor microenvironment with lowest fungal concentration and the storage area was highest.

Novel Laser Ablation Technology for Surface Decontamination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Chung H.

2004-06-01

Laser ablation for surface cleaning has been pursued for the removal of paint on airplanes. It has also been pursued for the cleaning of semiconductor surfaces. However, all these approaches have been pursued by laser ablation in air. For highly contaminated surface, laser ablation in air can easily cause secondary contamination. Thus it is not suitable to apply to achieve surface decontamination for DOE facilities since many of these facilities have radioactive contaminants on the surface. Any secondary contamination will be a grave concern. The objective of this project is to develop a novel technology for laser ablation in liquidmore » for surface decontamination. It aims to achieve more efficient surface decontamination without secondary contamination and to evaluate the economic feasibility for large scale surface decontamination with laser ablation in liquid. When laser ablation is pursued in the solution, all the desorbed contaminants will be confined in liquid. The contaminants can be precipitated and subsequently contained in a small volume for disposal. It can reduce the risk of the decontamination workers. It can also reduce the volume of contaminants dramatically.« less

Results of Geoenvironmental Studies (2013-2014) Applied to a Monitoring Water Quality Network in Real Time in the Atoyac River (upstream) Puebla, Mexico.

NASA Astrophysics Data System (ADS)

Rodriguez-Espinosa, P. F.; Tavera, E. M.; Morales-Garcia, S. S.; Muñoz-Sevilla, N. P.

2014-12-01

Results of geoenvironment studies, referents to geochemistry, weathering, size, mineral composition, and metals contained in sediments and physicochemical parameters of water in urban rivers associated with dam are presented. Emphasis on the interpretation of these results, was detect environmental susceptibility areas associated at the water quality in Upper basin of Atoyac River, Puebla, Mexico. The environmental sub secretary of the state government of Puebla, Mexico has initiated actions to clean up the urban Atoyac River, with measurements of physicochemical parameters associated of the water quality in real-time monitoring and sampling network along the river. The results identified an important role in the rivers, not only to receive and transport the contaminants associated with sedimentological and geochemical conditions, but magnified the effects of pollutant discharges. A significant concentration of hazardous metals in sediments of the dam, reflecting the geo-environmental conditions of anthropogenic Valsequillo Dam induction was determined. For example, a moderately contaminated Pb contaminated extreme class, and Cu and Zn contaminated with moderate to heavy contaminated under geoenvironment class index. Large concentration of clay minerals with larger surface areas was found there in the study, the minerals are definitely the fittest in nature to accept on their surfaces constitution of metals, metalloids and other contaminants which were reflected in the Geoenvironmental index. The results of the studies performed here enable us to locate monitoring stations and sampling network to physicochemical parameters in real time, in the areas of higher contamination found in geoenvironmental studies Atoyac High River Basin. Similarly, we can elucidate the origin of pollutants and monitoring agents reflected in BOD5 (223 mg / l) and COD (610 mg / l), suspended solids totals (136 mg / l) and dissolved solids totals (840 mg / l), in others. Recent hydrometric data associated with the concentration of pollutants, allow us to report COD transportation charges up to 1690 ton/day and 616 ton/day of BOD5. Where clearly detect the contributions of domestic sewage, industrial and agricultural in non-meteoric water.

A Complete Analytical Screening Identifies the Real Pesticide Contamination of Surface Waters

NASA Astrophysics Data System (ADS)

Moschet, Christoph; Wittmer, Irene; Simovic, Jelena; Junghans, Marion; Singer, Heinz; Stamm, Christian; Leu, Christian; Hollender, Juliane

2014-05-01

A comprehensive assessment of pesticides in surface waters is challenging due to the large number of potential contaminants. In Switzerland for example, roughly 500 active ingredients are registered as either plant protection agent (PPA) or as biocide. In addition, an unlimited number of transformations products (TPs) can enter or be formed in surfaced waters. Most scientific publications or regulatory monitoring authorities have implemented 15-40 pesticides in their analytics. Only a few TPs are normally included. Interpretations of the surface water quality based on these subsets remains error prone. In the presented study, we carried out a nearly complete analytical screening covering 86% of all polar organic pesticides (from agricultural and urban sources) in Switzerland (300 substances) and 134 TPs with limits of quantification in the low ng/L range. The comprehensive pesticide screening was conducted by liquid-chromatography coupled to high-resolution tandem mass spectrometry. Five medium-sized rivers (Strahler stream order 3-4, catchment size 35-105 km2), containing high percentiles of diverse crops, orchards and urban settlements in their catchments, were sampled from March till July 2012. Nine subsequent time-proportional bi-weekly composite samples were taken in order to quantify average concentrations. In total, 104 different active ingredients could be detected in at least one of the five rivers. Thereby, 82 substances were only registered as PPA, 20 were registered as PPA and as biocide and 2 were only registered as biocide. Within the PPAs, herbicides had the most frequent detections and the highest concentrations, followed by fungicides and insecticides. Most concentrations were found between 1 and 50 ng/L; however 31 substances (mainly herbicides) had concentrations above 100 ng/L and 3 herbicides above 1000 ng/L. It has to be noted that the measured concentrations are average concentrations over two weeks in medium sized streams and that maximum concentrations, especially in smaller streams, can be much higher. In each sample, between 30-50 pesticides were detected and the concentration sum of all active ingredients exceeded 1000 ng/L in 78% of the samples. Forty of the 134 investigated TPs could be detected in all the five rivers. As for the active ingredients, herbicide TPs dominated the detection frequency and the concentration range. Twelve TPs exceeded 100 ng/L in at least one sample. Between 15 and 25 TPs were detected in each sample, and 35% of all samples had a concentration sum of more than 1000 ng/L. The comparison of the measured concentrations of the parent compounds with chronic environmental quality standards (AA-EQS), revealed that 70% of all surface water samples exceeded at least one of them; in some samples up to seven AA-EQS exceedances were observed. In total, 19 substances (mainly herbicides and insecticides) exceeded critical concentrations in at least one sample. The conducted study showed that the investigated medium-sized rivers were exposed to a large number of pesticides and TPs over the whole sampling period. For a correct assessment of the surface water quality, it is therefore crucial to measure as many pesticides as possible in order to get the real contamination of pesticides in surface waters.

Selected veterinary pharmaceuticals in agricultural water and soil from land application of animal manure.

PubMed

Song, Wenlu; Ding, Yunjie; Chiou, Cary T; Li, Hui

2010-01-01

Veterinary pharmaceuticals are commonly administered to animals for disease control, and added into feeds at subtherapeutic levels to improve feeding efficiency. As a result of these practices, a certain fraction of the pharmaceuticals are excreted into animal manures. Land application of these manures contaminates soils with the veterinary pharmaceuticals, which can subsequently lead to contamination of surface and groundwaters. Information on the occurrence and fate of pharmaceuticals in soil and water is needed to assess the potential for exposure of at-risk populations and the impacts on agricultural ecosystems. In this study, we investigated the occurrence and fate of four commonly used veterinary pharmaceuticals (amprolium, carbadox, monensin, and tylosin) in a farm in Michigan. Amprolium and monensin were frequently detected in nearby surface water, with concentrations ranging from several to hundreds of nanograms per liter, whereas tylosin or carbadox was rarely found. These pharmaceuticals were more frequently detected in surface runoff during nongrowing season (October to April) than during growing season (May to September). Pharmaceuticals resulting from postharvest manure application appeared to be more persistent than those from spring application. High concentrations of pharmaceuticals in soils were generally observed at the sites where the respective concentrations in surface water were also high. For monensin, the ratios of soil-sorbed to aqueous concentrations obtained from field samples were within the order of the distribution coefficients obtained from laboratory studies. These results suggest that soil is a reservoir for veterinary pharmaceuticals that can be disseminated to nearby surface water via desorption from soil, surface runoff, and soil erosion.

Organic cleanliness of the Mars Science Laboratory sample transfer chain.

PubMed

Blakkolb, B; Logan, C; Jandura, L; Okon, A; Anderson, M; Katz, I; Aveni, G; Brown, K; Chung, S; Ferraro, N; Limonadi, D; Melko, J; Mennella, J; Yavrouian, A

2014-07-01

One of the primary science goals of the Mars Science Laboratory (MSL) Rover, Curiosity, is the detection of organics in Mars rock and regolith. To achieve this, the Curiosity rover includes a robotic sampling system that acquires rock and regolith samples and delivers it to the Sample Analysis at Mars (SAM) instrument on board the rover. In order to provide confidence that any significant organics detection result was Martian and not terrestrial in origin, a requirement was levied on the flight system (i.e., all sources minus the SAM instrument) to impart no more than 36 parts per billion (ppb by weight) of total reduced carbon terrestrial contamination to any sample transferred to the SAM instrument. This very clean level was achieved by a combination of a rigorous contamination control program on the project, and then using the first collected samples for a "dilution cleaning" campaign of the sample chain prior to delivering a sample to the SAM instrument. Direct cleanliness assays of the sample-contacting and other Flight System surfaces during pre-launch processing were used as inputs to determine the number of dilution cleaning samples needed once on Mars, to enable delivery of suitably clean samples to the SAM experiment. Taking into account contaminant redistribution during launch thorough landing of the MSL on Mars, the amount of residue present on the sampling hardware prior to the time of first dilution cleaning sample acquisition was estimated to be 60 ng/cm(2) on exposed outer surfaces of the sampling hardware and 20 ng/cm(2) on internal sample contacting surfaces; residues consisting mainly of aliphatic hydrocarbons and esters. After three dilution cleaning samples, estimated in-sample contamination level for the first regolith sample delivered to the SAM instrument at the Gale Crater "Rocknest" site was bounded at ≤10 ppb total organic carbon. A Project decision to forego ejecting the dilution cleaning sample and instead transfer the first drill-acquired sample at the "John Klein" site to SAM resulted in an estimated level of terrestrial contamination of ≤430 ppb. The estimated terrestrial contamination for portions from the second drill-acquired sample, at Cumberland, was ≤69 ppb; the estimate for a future, third, drilled sample is ≤38 ppb. These levels are comparable in magnitude to the SAM instrument blanks at the nanomole level (as chlorohydrocarbon).

Detecting and Estimating Contamination of Human DNA Samples in Sequencing and Array-Based Genotype Data

PubMed Central

Jun, Goo; Flickinger, Matthew; Hetrick, Kurt N.; Romm, Jane M.; Doheny, Kimberly F.; Abecasis, Gonçalo R.; Boehnke, Michael; Kang, Hyun Min

2012-01-01

DNA sample contamination is a serious problem in DNA sequencing studies and may result in systematic genotype misclassification and false positive associations. Although methods exist to detect and filter out cross-species contamination, few methods to detect within-species sample contamination are available. In this paper, we describe methods to identify within-species DNA sample contamination based on (1) a combination of sequencing reads and array-based genotype data, (2) sequence reads alone, and (3) array-based genotype data alone. Analysis of sequencing reads allows contamination detection after sequence data is generated but prior to variant calling; analysis of array-based genotype data allows contamination detection prior to generation of costly sequence data. Through a combination of analysis of in silico and experimentally contaminated samples, we show that our methods can reliably detect and estimate levels of contamination as low as 1%. We evaluate the impact of DNA contamination on genotype accuracy and propose effective strategies to screen for and prevent DNA contamination in sequencing studies. PMID:23103226

Occurrence and distribution of enteric viruses in shallow ground water and factors affecting well vulnerability to microbiological contamination in Worcester and Wicomico counties, Maryland

USGS Publications Warehouse

Banks, William S.L.; Klohe, Cheryl A.; Battigelli, David A.

2001-01-01

The U.S. Geological Survey, in cooperation with the Maryland Department of the Environment and the Wisconsin State Laboratory of Hygiene, conducted a study to characterize the occurrence and distribution of viral contamination in small (withdrawing less than 10,000 gallons per day) public water-supply wells screened in the water-table aquifer in the Coastal Plain in Worcester and Wicomico Counties, Maryland.Two hundred seventy-eight well sites were evaluated with regard to simulated ground-water flow paths, land use, natural soils groups, and well characteristics, such as well depth and well age. Flow and transport simulations of the water-table aquifer indicated that wells screened less than about 50 feet below land surface (shallow wells) were most vulnerable to surface contamination, which in some cases could originate from as far as 2,000 feet upgradient of the well. Animal-feeding and agricultural-storage operations were considered among the most likely sources for viral contamination; therefore, sites close to these activities were considered most vulnerable. Soil groups were evaluated with regard to depth to water and moisture-holding capacity. Wells with shallow depths to water or in very sandy soils were considered more vulnerable to contamination than deep wells (greater than 50 feet) and those completed in finer-grained soils. Older wells and wells where coliform bacteria had been detected in the past were classified as highly vulnerable. On the basis of this evaluation, 27 sites considered to be susceptible were sampled.Samples were collected by pumping up to 400 gallons of untreated well water through an electropositive filter. Water concentrates were subjected to cell-culture assay for the detection of culturable viruses and reverse-transcription polymerase chain reaction/gene probe assays to detect nonculturable viruses; grab samples were analyzed for somatic and male-specific coliphages, Bacteroides fragilis, Clostridium perfringens, enterococci, Escherichia coli, total coliforms, total oxidized nitrogen, dissolved organic carbon, organic nitrogen, total phosphate, orthophosphate, acid-neutralizing capacity, pH, specific conductance, temperature, and dissolved oxygen.Eleven percent of the samples analyzed (3 of 27) tested positive for either culturable viruses or the presence of viral ribonucleic acid. Approximately 15 percent of the samples (4 of 27) tested positive for one or more bacterial contaminants.

Detection of pathogenic Escherichia coli and microbiological quality of chilled shrimp sold in street markets.

PubMed

Barbosa, L J; Ribeiro, L F; Lavezzo, L F; Barbosa, M M C; Rossi, G A M; do Amaral, L A

2016-05-01

Foodborne illnesses caused by Escherichia coli are one of the most important gastrointestinal diseases and therefore represent a public health risk. The presence of E. coli in water or in products such as shrimp indicates faecal contamination. However, indicator micro-organisms can be used to evaluate the microbiological quality of food sold in markets. This study focused on detecting isolates of E. coli containing the genes stx1A, stx2A, eae, LTI, STa, STb, aggR and pCVD432 in chilled shrimp sold in street markets in the municipality of São Paulo, Brazil, and to assess the microbiological quality of this product. Enteropathogenic and enterotoxigenic E. coli pathotypes were detected on the surface of two chilled shrimp samples. Salmonella spp. was not isolated. In addition, contamination of surface and muscle of the shrimp samples was found to be correlated. The detection of EPEC and ETEC pathotypes in chilled shrimp sold in street markets in Brazil provides useful epidemiological information for public health authorities to improve food safety and public health. Shrimps are crustaceans commonly produced and consumed in Brazil. Specimens of Farfantepenaeus brasiliensis and Litopenaeus schmitti sold in street markets were examined by PCR to detect the presence of Escherichia coli pathotypes (enteropathogenic, enterotoxigenic, enterohemorrhagic and enteroinvasive). EPEC and ETEC strains were detected in whole shrimp. These findings provide useful information for public health authorities to improve the food safety and health of the Brazilian population. © 2016 The Society for Applied Microbiology.

Hepatitis A and E Viruses in Wastewaters, in River Waters, and in Bivalve Molluscs in Italy.

PubMed

Iaconelli, M; Purpari, G; Della Libera, S; Petricca, S; Guercio, A; Ciccaglione, A R; Bruni, R; Taffon, S; Equestre, M; Fratini, M; Muscillo, M; La Rosa, Giuseppina

2015-12-01

Several studies have reported the detection of hepatitis A (HAV) and E (HEV) virus in sewage waters, indicating a possibility of contamination of aquatic environments. The objective of the present study was to assess the occurrence of HAV and HEV in different water environments, following the route of contamination from raw sewage through treated effluent to the surface waters receiving wastewater discharges . Bivalve molluscan shellfish samples were also analyzed, as sentinel of marine pollution. Samples were tested by RT-PCR nested type in the VP1/2A junction for HAV, and in the ORF1 and ORF2 regions for HEV. Hepatitis A RNA was detected in 12 water samples: 7/21 (33.3%) raw sewage samples, 3/21 (14.3%) treated sewage samples, and 2/27 (7.4%) river water samples. Five sequences were classified as genotype IA, while the remaining 7 sequences belonged to genotype IB. In bivalves, HAV was detected in 13/56 samples (23.2%), 12 genotype IB and one genotype IA. Whether the presence of HAV in the matrices tested indicates the potential for waterborne and foodborne transmission is unknown, since infectivity of the virus was not demonstrated. HEV was detected in one raw sewage sample and in one river sample, both belonging to genotype 3. Sequences were similar to sequences detected previously in Italy in patients with autochthonous HEV (no travel history) and in animals (swine). To our knowledge, this is the first detection of HEV in river waters in Italy, suggesting that surface water can be a potential source for exposure .

Hazardous Drug Residue on Exterior Vial Surfaces: Evaluation of a Commercial Manufacturing Process

PubMed Central

Power, Luci A.; Sessink, Paul J. M.; Charbonneau, Flay

2014-01-01

Abstract Purpose: Hazardous drug residue on the exterior surface of drug vials poses a potential risk for exposure of health care workers involved in handling these products. The purpose of this article is to heighten the awareness of this serious issue and to evaluate a commercial manufacturing process for removing and containing hazardous drug (HD) residue on exterior vial surfaces. Additionally, findings from this study are interpreted, incorporated into the current body of evidence, and discussed by experts in this field. Methods: This study includes separate evaluations for the presence or absence of surface drug contamination on the vials of 3 HD products: 5-fluorouracil, cisplatin, and methotrexate. The drug products were packaged in vials using a patented prewashing/decontamination method, application of a polyvinylchloride (PVC) base, and use of clear glass vials. An additional step of encasing the vial in a shrink-wrapped sheath was used for 5-fluorouracil and cisplatin. Results: Of all 5-fluorouracil (110 vials), methotrexate (60 vials), and cisplatin (60 vials) tested, only 2 had detectable amounts of surface residue. One 5-fluorouracil vial was found to have approximately 4 mg of 5-fluorouracil on the surface of the vial. The second contaminated vial was cisplatin, which was discovered to have 131 ng of platinum, equal to 200 ng of cisplatin or 0.2 μL of cisplatin solution, on the vial sheath. Conclusion: Using validated extraction and analytic methods, all but 2 of the 230 tested vials were found to be free of surface drug contamination. Pharmacy leaders need to take an active role in promoting the need for clean HD vials. Manufacturers should be required to provide their clients with data derived from externally validated analytic studies, reporting the level of HD contamination on the exterior of their vial products. PMID:24958942

Fabrication of flexible gold nanorods polymer metafilm via phase transfer method as SERS substrate for detecting food contaminants.

PubMed

Yang, Nan; You, Ting-Ting; Gao, Yu-Kun; Zhang, Chen-Meng; Yin, Penggang

2018-06-08

Surface enhanced Raman scattering (SERS) has been widely used in detection of food safety due to the nondestructive examination property. Here, we reported a flexible SERS film based on polymer immobilized gold nanorods polymer metafilm. Polystyrene-polyisoprene-polystyrene (SIS), a transparent and flexible along with excellent elasticity polymer was chosen as main support of gold nanorods. A simple phase transfer progress was adopted to mix the gold nanorods with polymer which can further used in most water-insoluble polymers. The SERS film performed satisfactorily while tested in a series of standard Raman probes like crystal violet (CV) and malachite green (MG). Moreover, the excellent reproducibility and elastic properties make the film promising substrates in practical detection. Hence, the MG detection on fish surface and trace thiram detection on orange pericarp were inspected with the detection result of 1 × 10-10 M and 1 × 10-6 M which below the demand of National standard of China, exactly matching the realistic application requirements.

Hydrogeologic framework, hydrology, and refined conceptual model of groundwater flow for Coastal Plain aquifers at the Standard Chlorine of Delaware, Inc. Superfund Site, New Castle County, Delaware, 2005-12

USGS Publications Warehouse

Brayton, Michael J.; Cruz, Roberto M.; Myers, Luke; Degnan, James R.; Raffensperger, Jeff P.

2015-01-01

The regional hydrogeologic framework indicates that the site is underlain by Coastal Plain sediments of the Columbia, Merchantville, and Potomac Formations. Two primary aquifers underlying the site, the Columbia and the upper Potomac, are separated by the Merchantville Formation confining unit. Local groundwater flow in the surficial (Columbia) aquifer is controlled by topography and generally flows northward and discharges to nearby surface water. Regional flow within the Potomac aquifer is towards the southeast, and is strongly influenced by major water withdrawals locally. Previous investigations at the site indicated that contaminants, primarily benzene and chlorinated benzene compounds, were present in the Columbia aquifer in most locations; however, there were only limited detections in the upper Potomac aquifer as of 2004. From 2005 through 2012, the USGS designed a monitoring network, assisted with exploratory drilling, collected data at monitoring wells, conducted geophysical surveys, evaluated water-level responses in wells during pumping of a production well, and evaluated major aquifer withdrawals. Data collected through these efforts were used to refine the local conceptual flow system. The refined conceptual flow system for the site includes: (a) identification of gaps in confining units in the study area, (b) identification and correlation of multiple water-bearing sand intervals within the upper Potomac Formation, (c) connections between groundwater and surface water, (d) connections between shallow and deeper groundwater, (e) new water-level (or potentiometric surface) maps and inferred flow directions, and (f) identification of major local pumping well influences. The implications of the revised conceptual flow system on the occurrence and movement of site contaminants are that the resulting detection of contaminants in the upper Potomac aquifer at specific well locations can be attributed primarily to either advective lateral transport, direct vertical contaminant transport, or a combination of vertical and lateral movement resulting from changes in water withdrawal rates over time.

Assessment of Enterotoxin Production and Cross-Contamination of Staphylococcus aureus between Food Processing Materials and Ready-To-Eat Cooked Fish Paste.

PubMed

Tango, Charles Nkufi; Hong, Sung-Sam; Wang, Jun; Oh, Deog-Hwan

2015-12-01

This study evaluated Staphylococcus aureus growth and subsequent staphylococcal enterotoxin A production in tryptone soy broth and on ready-to-eat cooked fish paste at 12 to 37 °C, as well as cross-contamination between stainless steel, polyethylene, and latex glove at room temperature. A model was developed using Barany and Roberts's growth model, which satisfactorily described the suitable growth of S. aureus with R(2)-adj from 0.94 to 0.99. Except at 12 °C, S. aureus cells in TSB presented a lag time lower (14.64 to 1.65 h), grew faster (0.08 to 0.31 log CFU/h) and produced SEA at lower cell density levels (5.65 to 6.44 log CFU/mL) compare to those inoculated on cooked fish paste with data of 16.920 to 1.985 h, 0.02 to 0.23 log CFU/h, and 6.19 to 7.11 log CFU/g, respectively. Staphylococcal enterotoxin type A (SEA) visual immunoassay test showed that primary SEA detection varied considerably among different storage temperature degrees and media. For example, it occurred only during exponential phase at 30 and 37 °C in TSB, but in cooked fish paste it took place at late exponential phase of S. aureus growth at 20 and 25 °C. The SEA detection test was negative on presence of S. aureus on cooked fish paste stored at 12 and 15 °C, although cell density reached level of 6.12 log CFU/g at 15 °C. Cross-contamination expressed as transfer rate of S. aureus from polyethylene surface to cooked fish paste surface was slower than that observed with steel surface to cooked fish paste under same conditions. These results provide helpful information for controlling S. aureus growth, SEA production and cross-contamination during processing of cooked fish paste. © 2015 Institute of Food Technologists®

An innate immune system-mimicking, real-time biosensing of infectious bacteria.

PubMed

Seo, Sung-Min; Jeon, Jin-Woo; Kim, Tae-Yong; Paek, Se-Hwan

2015-09-07

An animal cell-based biosensor was investigated to monitor bacterial contamination in an unattended manner by mimicking the innate immune response. The cells (RAW 264.7 cell line) were first attached onto the solid surfaces of a 96-well microtiter plate and co-incubated in the culture medium with a sample that might contain bacterial contaminants. As Toll-like receptors were present on the cell membrane surfaces, they acted as a sentinel by binding to pathogen-associated molecular patterns (PAMPs) of any contaminant. Such biological recognition initiates signal transmission along various pathways to produce different proinflammatory mediators, one of which, tumor necrosis factor-α (TNF-α) was measured using an immunosensor. To demonstrate automated bacterium monitoring, a capture antibody specific for TNF-α was immobilized on an optical fiber sensor tip and then used to measure complex formation in a label-free sensor system (e.g., Octet Red). The sensor response time depended significantly on the degree of agitation of the culture medium, controlling the biological recognition and further autocrine/paracrine signaling by cytokines. The response, particularly under non-agitated conditions, was also influenced by the medium volume, revealing a local gradient change of the cytokine concentration and also acidity, caused by bacterial growth near the bottom surfaces. A biosensor system retaining 50 μL medium and not employing agitation could be used for the early detection of bacterial contamination. This novel biosensing model was applied to the real-time monitoring of different bacteria, Shigella sonnei, Staphylococcus aureus, and Listeria monocytogenes. They (<100 CFU mL(-1)) could be detected automatically within the working time. Such analysis was carried out without any manual handling regardless of the bacterial species, suggesting the concept of non-targeted bacterial real-time monitoring. This technique was further applied to real sample testing (e.g., with milk) to exemplify, for example, the food quality control process without using any additional sample pretreatment such as magnetic concentration.

Vertical Distribution and Estimated Doses from Artificial Radionuclides in Soil Samples around the Chernobyl Nuclear Power Plant and the Semipalatinsk Nuclear Testing Site

PubMed Central

Taira, Yasuyuki; Hayashida, Naomi; Tsuchiya, Rimi; Yamaguchi, Hitoshi; Takahashi, Jumpei; Kazlovsky, Alexander; Urazalin, Marat; Rakhypbekov, Tolebay; Yamashita, Shunichi; Takamura, Noboru

2013-01-01

For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides (241Am, 134Cs, 137Cs, and 60Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides (241Am, 57Co, 137Cs, 95Zr, 95Nb, 58Co, and 60Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public. PMID:23469013

Vertical distribution and estimated doses from artificial radionuclides in soil samples around the Chernobyl nuclear power plant and the Semipalatinsk nuclear testing site.

PubMed

Taira, Yasuyuki; Hayashida, Naomi; Tsuchiya, Rimi; Yamaguchi, Hitoshi; Takahashi, Jumpei; Kazlovsky, Alexander; Urazalin, Marat; Rakhypbekov, Tolebay; Yamashita, Shunichi; Takamura, Noboru

2013-01-01

For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides ((241)Am, (134)Cs, (137)Cs, and (60)Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides ((241)Am, (57)Co, (137)Cs, (95)Zr, (95)Nb, (58)Co, and (60)Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public.

Areal studies aid protection of ground-water quality in Illinois, Indiana, and Wisconsin

USGS Publications Warehouse

Mills, Patrick C.; Kay, Robert T.; Brown, Timothy A.; Yeskis, Douglas J.

1999-01-01

In 1991, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, initiated studies designed to characterize the ground-water quality and hydrogeology in northern Illinois, and southern and eastern Wisconsin (with a focus on the north-central Illinois cities of Belvidere and Rockford, and the Calumet region of northeastern Illinois and northwestern Indiana). These areas are considered especially susceptible to ground-water contamination because of the high density of industrial and waste-disposal sites and the shallow depth to the unconsolidated sand and gravel aquifers and the fractured, carbonate bedrock aquifers that underlie the areas. The data and conceptual models of ground-water flow and contaminant distribution and movement developed as part of the studies have allowed Federal, State, and local agencies to better manage, protect, and restore the water supplies of the areas. Water-quality, hydrologic, geologic, and geophysical data collected as part of these areal studies indicate that industrial contaminants are present locally in the aquifers underlying the areas. Most of the contaminants, particularly those at concentrations that exceeded regulatory water-quality levels, were detected in the sand and gravel aquifers near industrial or waste-disposal sites. In water from water-supply wells, the contaminants that were present generally were at concentrations below regulatory levels. The organic compounds detected most frequently at concentrations near or above regulatory levels varied by area. Trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane (volatile chlorinated compounds) were most prevalent in north-central Illinois; benzene (a petroleum-related compound) was most prevalent in the Calumet region. Differences in the type of organic compounds that were detected in each area likely reflect differences in the types of industrial sites that predominate in the areas. Nickel and aluminum were the trace metals detected most frequently at concentrations above regulatory levels in both areas. Contaminants in the shallow sand and gravel aquifers and carbonate aquifers appear to have moved with ground water discharging to local lakes, streams, and wetlands. Ground-water flow and possibly contaminant movement is concentrated in the weathered surface zones and in deeper fractures of the carbonate aquifers underlying both areas.

Virus occupational exposure in solid waste processing facilities.

PubMed

Carducci, Annalaura; Federigi, Ileana; Verani, Marco

2013-11-01

It is well known that workers involved in the management of solid waste are at risk of exposure to bioaerosol, which is generally studied in relation to bacteria, fungi, and endotoxins. However, to date, there have been no reports on the incidence of work-related infectious diseases. To determine if occupational exposure to viruses occurs upon exposure to waste-related activities, monitoring was carried out in a landfill, a waste recycling plant, an incineration plant, and a waste collection vehicles. Air and surfaces were sampled and analyzed for torque teno virus (TTV), human adenovirus (HAdV), norovirus, rotavirus, and enterovirus using polymerase chain reaction (PCR)-based techniques. Positivity was confirmed by sequencing and quantification with real-time PCR; infectivity was also tested for culturable viruses. Samples were analyzed in parallel for mean total bacterial and fungi counts in both the summer and winter. In total, 30% (12/40) of air and 13.5% (5/37) of surface samples collected in plants were positive for HAdV and TTV. Among the eight HAdV-positive samples, six (75%), revealed in landfill and recycling plant air and in incinerator and waste vehicles surfaces, were able to replicate in cell culture and were subsequently confirmed as infective. The frequency of detection of virus-positive samples was similar in both seasons, but with evident differences in the type of virus detected: TTV and HAdV were more frequently detected in the summer and winter, respectively. The area of highest viral contamination was the paper selection landfill. Fungi and bacterial contamination did not correlate with viral presence or concentration. In conclusion, we evidence that working with solid and liquid waste can lead to infectious viruses, included in Group 2 of the European Directive 90/679/CEE pathogens list; thus, further investigation on the sources and routes of contamination is needed in order to assess the occupational risk.

Development of a human-specific B. thetaiotaomicron IMS ...

EPA Pesticide Factsheets

Immunomagnetic separation/adenosine triphosphate (IMS/ATP) assays utilize paramagnetic beads and target-specific antibodies to isolate target organisms. Following isolation, adenosine tri-phosphate (ATP) is extracted from the target population and quantified. An inversely-coupled (Inv-IMS/ATP)assay for detection of Bacteroides thetaiotaomicron was developed and applied for rapid detection of human-associated fecal contamination in surface waters in Baja California. Specificity of the assay was tested against challenge solutions of varying concentrations of dog, gull, horse and chicken feces, and a field validation survey of coastal and WWTP effluent water quality in Rosarito and Enseneda, Baja California was conducted. Inv IMS/ATP measurements made shown to be specific and sensitive to human fecal contamination. At test concentrations of less than 1000 MPN ENT/100 mL, sensitivity and specificity of the assay both exceeded 80%. Moreover, the Inv-IMS/ATP assay yielded measurements of viable B. thetaiotaomicron that were comparable to the HF183 human marker in complex surface waters impacted with both wastewater and runoff, and the Inv-IMS/ATP assay was able to effectively differentiate between surface waters impacted with adequately and inadequately treated wastewater. The Inv-IMS/ATP assays shows promise for rapid evaluation of recreational water quality in areas where access to more expensive methods is limited and in areas where water quality in unpredicta

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of Salmonella contamination... REQUIREMENTS Standard Procedures § 113.30 Detection of Salmonella contamination. The test for detection of Salmonella contamination provided in this section shall be conducted when such a test is prescribed in an...

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Detection of Salmonella contamination... REQUIREMENTS Standard Procedures § 113.30 Detection of Salmonella contamination. The test for detection of Salmonella contamination provided in this section shall be conducted when such a test is prescribed in an...

Pushpoint sampling for defining spatial and temporal variations in contaminant concentrations in sediment pore water near the ground-water / surface-water interface

USGS Publications Warehouse

Zimmerman, Marc J.; Massey, Andrew J.; Campo, Kimberly W.

2005-01-01

During four periods from April 2002 to June 2003, pore-water samples were taken from river sediment within a gaining reach (Mill Pond) of the Sudbury River in Ashland, Massachusetts, with a temporary pushpoint sampler to determine whether this device is an effective tool for measuring small-scale spatial variations in concentrations of volatile organic compounds and selected field parameters (specific conductance and dissolved oxygen concentration). The pore waters sampled were within a subsurface plume of volatile organic compounds extending from the nearby Nyanza Chemical Waste Dump Superfund site to the river. Samples were collected from depths of 10, 30, and 60 centimeters below the sediment surface along two 10-meter-long, parallel transects extending into the river. Twenty-five volatile organic compounds were detected at concentrations ranging from less than 1 microgram per liter to hundreds of micrograms per liter (for example, 1,2-dichlorobenzene, 490 micrograms per liter; cis-1,2-dichloroethene, 290 micrograms per liter). The most frequently detected compounds were either chlorobenzenes or chlorinated ethenes. Many of the compounds were detected only infrequently. Quality-control sampling indicated a low incidence of trace concentrations of contaminants. Additional samples collected with passive-water-diffusion-bag samplers yielded results comparable to those collected with the pushpoint sampler and to samples collected in previous studies at the site. The results demonstrate that the pushpoint sampler can yield distinct samples from sites in close proximity; in this case, sampling sites were 1 meter apart horizontally and 20 or 30 centimeters apart vertically. Moreover, the pushpoint sampler was able to draw pore water when inserted to depths as shallow as 10 centimeters below the sediment surface without entraining surface water. The simplicity of collecting numerous samples in a short time period (routinely, 20 to 30 per day) validates the use of a pushpoint sampler as a highly effective tool for mapping the extent of contaminated subsurface plumes, determining their constituents and loadings, and performing technical studies that may be relevant to bioremediation and other activities.

Visualization of hospital cleanliness in three Japanese hospitals with a tendency toward long-term care

PubMed Central

2014-01-01

Background Hospital cleanliness in hospitals with a tendency toward long-term care in Japan remains unevaluated. We therefore visualized hospital cleanliness in Japan over a 2-month period by two distinct popular methods: ATP bioluminescence (ATP method) and the standard stamp agar method (stamp method). Methods The surfaces of 752 sites within nurse and patient areas in three hospitals located in a central area of Sapporo, Japan were evaluated by the ATP and stamp methods, and each surface was sampled 8 times in 2 months. These areas were located in different ward units (Internal Medicine, Surgery, and Obstetrics and Gynecology). Detection limits for the ATP and stamp methods were determined by spike experiments with a diluted bacterial solution and a wipe test on student tables not in use during winter vacation, respectively. Values were expressed as the fold change over the detection limit, and a sample with a value higher than the detection limit by either method was defined as positive. Results The detection limits were determined to be 127 relative light units (RLU) per 100 cm2 for the ATP method and 5.3 colony-forming units (CFU) per 10 cm2 for the stamp method. The positive frequency of the ATP and stamp methods was 59.8% (450/752) and 47.7% (359/752), respectively, although no significant difference in the positive frequency among the hospitals was seen. Both methods revealed the presence of a wide range of organic contamination spread via hand touching, including microbial contamination, with a preponderance on the entrance floor and in patient rooms. Interestingly, the data of both methods indicated considerable variability regardless of daily visual assessment with usual wiping, and positive surfaces were irregularly seen. Nurse areas were relatively cleaner than patient areas. Finally, there was no significant correlation between the number of patients or medical personnel in the hospital and organic or microbiological contamination. Conclusions Ongoing daily hospital cleanliness is not sufficient in Japanese hospitals with a tendency toward long-term care. PMID:24593868

Visualization of hospital cleanliness in three Japanese hospitals with a tendency toward long-term care.

PubMed

Watanabe, Reina; Shimoda, Tomoko; Yano, Rika; Hayashi, Yasuhiro; Nakamura, Shinji; Matsuo, Junji; Yamaguchi, Hiroyuki

2014-03-04

Hospital cleanliness in hospitals with a tendency toward long-term care in Japan remains unevaluated. We therefore visualized hospital cleanliness in Japan over a 2-month period by two distinct popular methods: ATP bioluminescence (ATP method) and the standard stamp agar method (stamp method). The surfaces of 752 sites within nurse and patient areas in three hospitals located in a central area of Sapporo, Japan were evaluated by the ATP and stamp methods, and each surface was sampled 8 times in 2 months. These areas were located in different ward units (Internal Medicine, Surgery, and Obstetrics and Gynecology). Detection limits for the ATP and stamp methods were determined by spike experiments with a diluted bacterial solution and a wipe test on student tables not in use during winter vacation, respectively. Values were expressed as the fold change over the detection limit, and a sample with a value higher than the detection limit by either method was defined as positive. The detection limits were determined to be 127 relative light units (RLU) per 100 cm2 for the ATP method and 5.3 colony-forming units (CFU) per 10 cm2 for the stamp method. The positive frequency of the ATP and stamp methods was 59.8% (450/752) and 47.7% (359/752), respectively, although no significant difference in the positive frequency among the hospitals was seen. Both methods revealed the presence of a wide range of organic contamination spread via hand touching, including microbial contamination, with a preponderance on the entrance floor and in patient rooms. Interestingly, the data of both methods indicated considerable variability regardless of daily visual assessment with usual wiping, and positive surfaces were irregularly seen. Nurse areas were relatively cleaner than patient areas. Finally, there was no significant correlation between the number of patients or medical personnel in the hospital and organic or microbiological contamination. Ongoing daily hospital cleanliness is not sufficient in Japanese hospitals with a tendency toward long-term care.

A fundamental approach to the sticking of insect residues to aircraft wings

NASA Technical Reports Server (NTRS)

Eiss, N. S., Jr.; Wightman, J. P.; Gilliam, D. R.; Siochi, E. J.

1984-01-01

A proposed testing scheme is described for obtaining data on the effects of surface roughness and surface energy on insect adhesion. The road test apparatus is discussed as well as surface preparation techniques. Uncoated and polymer coated metal substrates were analyzed by SEM/ESCA/IRS before and following collision with insects. Critical surface tensions of unexposed Nyebar and poly sulfone coatings were 10 and 33 dynes/cm, respectively, as determined from contact angles. A total of 95% of insect residues collected belong to order Diptera. Significantly less insect debris was detected on the coated plates as compared to the uncoated plates. Minimal contamination at the 5 nm level of both coated and uncoated plates occurs even after hours of exposure to road conditions as determined by ESCA analysis. The presence of nitrogen detected by ESCA on exposed plates is unequivocal evidence for insect residues left on plates.

Scatter from optical components; Proceedings of the Meeting, San Diego, CA, Aug. 8-10, 1989

NASA Astrophysics Data System (ADS)

Stover, John C.

Various papers on scatter from optical components are presented. Individual topics addressed include: BRDF of SiC and Al foam compared to black paint at 3.39 microns, characterization of optical baffle materials, bidirectional transmittance distribution function of several IR materials at 3.39 microns, thermal cycling effects on the BRDF of beryllium mirrors, BTDV of ZnSe with multilayer coatings at 3.39 microns, scattering from contaminated surfaces, cleanliness correlation by BRDF and PFO instruments, contamination effects on optical surfaces, means of eliminating the effects of particulate contamination on scatter measurements of superfine optical surfaces, vacuum BRDF measurement of cryogenic optical surfaces, Monte Carlo simulation of contaminant transport to and deposition on complex spacecraft surfaces, surface particle observation and BRDF predictions, satellite material contaminant optical properties, dark field photographic techniques for documenting optical surface contamination, design of a laboratory study of contaminant film darkening in space, contamination monitoring approaches for EUV space optics.

Public health assessment for petitioned Phelps Dodge Corp Douglas Reduction Works, Douglas, Cochise County, Arizona, Region 9. Cerclis No. AZD008397143. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The Phelps-Dodge site, a former copper-smelting operation just outside Douglas and possibly Agua Prieta, Sonora, Mexico. This site contributed to lead-contaminated surface soils in residential areas in Douglas. Exposure to the lead-contaminated soils may have contributed and/or caused elevated blood levels in children living in both Douglas, AZ and Agua Prieta, Sonora, Mexico. Past emissions from the smelter included arsenic, lead, sulfur dioxide, inhalable particulate matter, and other heavy metals. The levels detected by air monitoring were elevated above health guidelines.

Organic and metal contamination in marine surface sediments of Guánica Bay, Puerto Rico.

PubMed

Whitall, David; Mason, Andrew; Pait, Anthony; Brune, Lia; Fulton, Michael; Wirth, Ed; Vandiver, Lisa

2014-03-15

Land based sources of pollution have the potential to adversely impact valuable coral reef ecosystems. In Guánica Bay (Puerto Rico) sediment samples collected and analyzed in 2009 demonstrate unusually high concentrations of total chlordane, total PCBs, nickel and chromium. A variety of other contaminants (total DDT, total PAHs, As, Cu, Hg, and Zn) were also at levels which may indicate sediment toxicity. With the exception of chromium, all of these contaminants were detected in coral tissues (Porites astreoides), although it is unclear at what level these contaminants affect coral health. PCBs and chlordane are environmentally persistent and likely represent legacy pollution from historical uses in close geographic proximity to the Bay. We hypothesize that the high nickel and chromium levels are due to a combination of naturally high Ni and Cr in rock and soils in the watershed, and enhanced (human driven) erosional rates. Published by Elsevier Ltd.

Ignition of contaminants by impact of high-pressure oxygen

NASA Technical Reports Server (NTRS)

Pedley, Michael D.; Pao, Jenn-Hai; Bamford, Larry; Williams, Ralph E.; Plante, Barry

1988-01-01

The ignition of oil-film contaminants in high-pressure gaseous oxygen systems, caused by rapid pressurization, was investigated using the NASA/White Sands Test Facility's large-volume pneumatic impact test system. The test section consisted of stainless steel lines, contaminated on the inside surface with known amounts of Mobil DTE 24 oil and closed at one end, which was attached to a high-pressure oxygen system; the test section was pressurized to 48 MPa by opening a high-speed valve. Ignition of the oil was detected by a photocell attached to the closed end of the line. It was found that the frequency of ignition increased as a function of both the concentration of oil and of the pressure of the impacting oxygen. The threshold of ignition was between 25 and 65 mg/sq m. The results were correlated with the present NASA and Compressed Gas Association requirements for maximum levels of organic contaminants.

Highly contaminated areas as sources of pollution for adjoining ecosystems: The case of Augusta Bay (Central Mediterranean).

PubMed

Di Leonardo, R; Mazzola, A; Tramati, C D; Vaccaro, A; Vizzini, S

2014-12-15

An assessment of trace element and polycyclic aromatic hydrocarbon (PAH) contamination based on surface sediments collected in summer 2012 was carried out in Priolo Bay adjoining one of the most polluted areas of the Mediterranean Sea, the industrial Augusta harbour (Italy, Central Mediterranean). Inorganic and organic contaminants were generally not remarkable. Occasional elevated concentrations of Hg, Cd, Ni and PAHs exceeding sediment quality guidelines were detected in the northern sector of Priolo Bay, close to Augusta harbour, possibly as a result of water drainage of industrialised and urbanised areas and/or potential direct export of contaminated material from Augusta harbour, whose influence on the adjoining Priolo Bay ecosystem cannot be ruled out. By domino effect, Priolo sediments may therefore become a potential source of pollutants and may represent a threat to the biota. Copyright © 2014 Elsevier Ltd. All rights reserved.

Suppression of stimulus artifact contaminating electrically evoked electromyography.

PubMed

Liu, Jie; Li, Sheng; Li, Xiaoyan; Klein, Cliff; Rymer, William Z; Zhou, Ping

2014-01-01

Electrical stimulation of muscle or nerve is a very useful technique for understanding of muscle activity and its pathological changes for both diagnostic and therapeutic purposes. During electrical stimulation of a muscle, the recorded M wave is often contaminated by a stimulus artifact. The stimulus artifact must be removed for appropriate analysis and interpretation of M waves. The objective of this study was to develop a novel software based method to remove stimulus artifacts contaminating or superimposing with electrically evoked surface electromyography (EMG) or M wave signals. The multiple stage method uses a series of signal processing techniques, including highlighting and detection of stimulus artifacts using Savitzky-Golay filtering, estimation of the artifact contaminated region with Otsu thresholding, and reconstruction of such region using signal interpolation and smoothing. The developed method was tested using M wave signals recorded from biceps brachii muscles by a linear surface electrode array. To evaluate the performance, a series of semi-synthetic signals were constructed from clean M wave and stimulus artifact recordings with different degrees of overlap between them. The effectiveness of the developed method was quantified by a significant increase in correlation coefficient and a significant decrease in root mean square error between the clean M wave and the reconstructed M wave, compared with those between the clean M wave and the originally contaminated signal. The validity of the developed method was also demonstrated when tested on each channel's M wave recording using a linear electrode array. The developed method can suppress stimulus artifacts contaminating M wave recordings.

Contamination assessments of surface water in coastal lagoon (Maluan Bay, China) incorporating biomarker responses and bioaccumulation in hepatopancreas of exposed shrimp (Litopenaeus vannamei)--an integrative approach.

PubMed

Wang, Zaosheng; Dong, Xiaoxia; Zhou, Shilei; Yan, Changzhou; Yan, Yijun; Chi, Qiaoqiao

2014-01-01

Maluan Bay, characterized by various degrees of anthropogenic contamination, is considered as one of the most industrialized and urbanized coastal lagoon in China, where large amounts of metal contaminants in surface water and biota were detected in previous studies. However, no clear discriminating power among sampling sites could be made only through comparisons between contaminant levels and Environmental Quality Standards and especially biological-based monitoring integrating biomarkers and bioaccumulation of exposure are scarce. For this purpose, antioxidants enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and glutathione-S-transferase were assessed using the hepatopancreas of shrimp Litopenaeus vannamei after 7 days laboratory exposure under controlled conditions to characterize the effects of polluted waters to shrimps. The metal concentrations of sampled water and bioaccumulation in hepatopancreatic tissues were also analyzed, and data were linked to biomarkers' responses by multivariate (principal component analysis-factor) analysis. A representation of estimated factor scores was performed to confirm the factor descriptions classifying the pollution status and characterizing the studied sites, which pointed out the impact of multiple sources of contaminants to the water quality and provided further evidences to the existence of clear pollution and toxicological gradients in critical areas. The results of the present investigation underlined that the integrated approach could be a powerful tool for the identification of causal toxic contaminants in complex mixtures and the assessment of human-induced environmental quality of the system in coastal zones.

Real-time surrogate analysis for potential oil and gas contamination of drinking water resources

NASA Astrophysics Data System (ADS)

Son, Ji-Hee; Carlson, Kenneth H.

2015-09-01

Public concerns related to the fast-growing shale oil and gas industry have increased during recent years. The major concern regarding shale gas production is the potential of fracturing fluids being injected into the well or produced fluids flowing out of the well to contaminate drinking water resources such as surface water and groundwater. Fracturing fluids contain high total dissolved solids (TDS); thus, changes in TDS concentrations in groundwater might indicate influences of fracturing fluids. An increase of methane concentrations in groundwater could also potentially be due to hydraulic fracturing activities. To understand the possible contamination of groundwater by fracturing activities, real-time groundwater monitoring is being implemented in the Denver-Julesburg basin of northeast Colorado. A strategy of monitoring of surrogate parameters was chosen instead of measuring potential contaminants directly, an approach that is not cost effective or operationally practical. Contaminant surrogates of TDS and dissolved methane were proposed in this study, and were tested for correlation and data distribution with laboratory experiments. Correlations between TDS and electrical conductivity (EC), and between methane contamination and oxidation-reduction potential (ORP) were strong at low concentrations of contaminants (1 mg/L TDS and 0.3 mg/L CH4). Dissolved oxygen (DO) was only an effective surrogate at higher methane concentrations (≥2.5 mg/L). The results indicated that EC and ORP are effective surrogates for detecting concentration changes of TDS and methane, respectively, and that a strategy of monitoring for easy to measure parameters can be effective detecting real-time, anomalous behavior relative to a predetermined baseline.

Occurrence of selected contaminants in water, fish tissue, and streambed sediments in central Nebraska, 1992-95

USGS Publications Warehouse

Frenzel, Steven A.

1996-01-01

Surface and ground water in Nebraska may contain contaminants resulting from human activities. For purposes of this publication, a contaminant is any element or compound whose presence may affect the water's suitability for certain uses. For example, herbicide concentrations may exceeed the U.S. Environmental Protection Agency's (USEPA) Health Advisory Levels (HAL) for drinking water or trace-element concentrations may exceed guidelines for the protection of aquatic life. In general, the contaminats discussed in this report enter the aquatic system through nonpoint-source runoff from agricultural lands that dominate the Nebraska landscape. However,because this assessment was conducted as part of a larger, national program, a screening for contaminants with non-agricultural origins was included.The measurement of water quality involves a variety of steps, each contributing unique information while also aggregating to an overall assessment. One aspect of water-quality assesment is to describe the occurrence and distribution of contaminants. Some contaminants may be hundreds or thousands of times more concentrated in the tissues of aquatic organisms or in fine sediments than they are in the water. As a result, fish tissue and streambed sediments are well suited for the detection of certain contaminants. For example, pesticides used in the United States prior to the early 1970's, such as DDT, may have degraded into more stable but still toxic compounds that are highly concentrated in fish tissues. Conversely, other contaminants are not concentrated in sediments or tissues but are readily detected in water samples. Organonitrogen herbicides (such as atrazine), the most commonly used herbicides in Nebraska, are examples of water-soluble contaminants.Several sampling strategies were used to address specific questions. Some sites were sampled repeatedly through time and during all hydrologic conditions, whereas others were sampled only once to determine presence of contaminants. Because a strong relation between concentration and streamflow often exists for contaminants originating from nonpoint sources, streams typically were sampled near gaging stations that monitor streamflow.

Bioinspired Surface Treatments for Improved Decontamination: Commercial Products

DTIC Science & Technology

2017-07-28

simulants paraoxon, methyl salicylate, dimethyl methylphosphate, and diisopropyl fluorophosphates following treatment of contaminated surfaces with a...treatment of contaminated surfaces with a soapy water solution is reported along with droplet diffusion on the surfaces and wetting angles...Defense Program (CBDP) seeks to provide protection of forces in a contaminated environment including contamination avoidance, individual protection

Differential Group-Velocity Detection of Fluid Paths Leland Timothy Long

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Leland Timothy

2003-06-01

The objective of differential surface-wave interpretation is to identify and locate temporal perturbations in the shear-wave velocity. Perturbations in phase velocity are created when the stress and/or fluid content of soils changes, such as in pumping to remove or flush out contaminants. Differential surface wave analysis is a potential method to track the movement of fluids during remediation programs. This proposal is to develop and test this new technology to aid in the selection and design of remediation options in shallow aquifers.

Harvesting contaminants from liquid

DOEpatents

Simpson, John T.; Hunter, Scott R.

2016-05-31

Disclosed are examples of apparatuses for evaporative purification of a contaminated liquid. In each example, there is a vessel for storing the contaminated fluid. The vessel includes a surface coated with a layer of superhydrophobic material and the surface is at least partially in contact with the contaminated liquid. The contaminants do not adhere to the surface as the purified liquid evaporates, thus allowing the contaminants to be harvested.

Impedance biosensor based on interdigitated electrode array for detection of E.coli O157:H7 in food products

NASA Astrophysics Data System (ADS)

Ghosh Dastider, Shibajyoti; Barizuddin, Syed; Dweik, Majed; Almasri, Mahmoud F.

2012-05-01

An impedance biosensor was designed, fabricated and tested for detection of viable Escherichia coli O157:H7 in food samples. This device consists of interdigitated microelectrode array (IDEA) fabricated using thin layer of sputtered gold, embedded under a polydimethylsiloxane (PDMS) microchannel. The array of electrodes is designed to detect viable EColi in different food products. The active surface area of the detection array was modified using goat anti-E.coli polyclonal IgG antibody. Contaminated food samples were tested by infusing the supernatant containing bacteria over the IDEA's, through the microchannel. Antibody-antigen binding on the electrodes results in impedance change. Four serial concentrations of E.coli contaminated food samples (3x102 CFUmL-1 to 3x105 CFUmL-1) were tested. The biosensor successfully detected the E.coli samples, with the lower detection limit being 3x103 CFUmL-1 (up to 3cells/μl). Comparing the test results with an IDEA impedance biosensor without microchannel (published elsewhere) indicates that this biosensor have two order of magnitude times higher sensitivity. The proposed biosensor provides qualitative and quantitative detection, and potentially could be used for detection of other type of bacteria by immobilizing the specific type of antibody.

Removal of hydrocarbon contaminant film from spacecraft optical surfaces using a radiofrequency-excited oxygen plasma.

NASA Technical Reports Server (NTRS)

Beverly, W. D.; Gillete, R. B.; Cruz, G. A.

1973-01-01

Results of a study on the feasibility of removing contaminant films from optical surfaces in vacuum, using an oxygen plasma, are discussed. Contaminant films were deposited onto optical surfaces from butadiene and methane gases at a pressure of about 4 torr in the presence of ultraviolet radiation. Optical surfaces evaluated included ultraviolet-reflecting mirrors, gratings, quartz disks, and spacecraft thermal control surfaces. In general, it was found that contaminants could be removed successfully from surfaces using an oxygen plasma. Exceptions were the white-paint thermal control surfaces, which, when contaminated, degraded further during exposure to the oxygen plasma.

Long-term recovery of PCB-contaminated surface sediments at the Sangamo-westonl Twelvemile Creek/lake Hartwell Superfund Site.

PubMed

Brenner, Richard C; Magar, Victor S; Ickes, Jennifer A; Foote, Eric A; Abbott, James E; Bingler, Linda S; Crecelius, Eric A

2004-04-15

Natural recovery of contaminated sediments relies on burial of contaminated sediments with increasingly clean sediments over time (i.e., natural capping). Natural capping reduces the risk of resuspension of contaminated surface sediments, and it reduces the potential for contaminant transport into the food chain by limiting bioturbation of contaminated surface or near-surface sediments. This study evaluated the natural recovery of surface sediments contaminated with polychlorinated biphenyls (PCBs) at the Sangamo-Weston/Twelvemile Creek/Lake Hartwell Superfund Site (Lake Hartwell), Pickens County, SC. The primary focus was on sediment recovery resulting from natural capping processes. Total PCB (t-PCB), lead-210 (210Pb), and cesium-137 (137Cs) sediment core profiles were used to establish vertical t-PCB concentration profiles, age date sediments, and determine surface sedimentation and surface sediment recovery rates in 18 cores collected along 10 transects. Four upgradient transects in the headwaters of Lake Hartwell were impacted by historical sediment releases from three upgradient sediment impoundments. These transects were characterized by silt/ clay and sand layering. The highest PCB concentrations were associated with silt/clay layers (1.8-3.5% total organic carbon (TOC)), while sand layers (0.05-0.32% TOC) contained much lower PCB concentrations. The historical sediment releases resulted in substantial burial of PCB-contaminated sediment in the vicinity of these four cores; each core contained less than 1 mg/kg t-PCBs in the surface sand layers. Cores collected from six downgradient Lake Hartwell transects consisted primarily of silt and clay (0.91-5.1% TOC) and were less noticeably impacted by the release of sand from the impoundments. Vertical t-PCB concentration profiles in these cores began with relatively low PCB concentrations at the sediment-water interface and increased in concentration with depth until maximum PCB concentrations were measured at approximately 30-60 cm below the sediment-water interface, ca. 1960-1980. Maximum t-PCB concentrations were followed by progressively decreasing concentrations with depth until the t-PCB concentrations approached the detection limit, where sediments were likely deposited before the onset of PCB use at the Sangamo-Weston plant. The sediments containing the maximum PCB concentrations are associated with the period of maximum PCB release into the watershed. Sedimentation rates averaged 2.1 +/- 1.5 g/(cm2 yr) for 12 of 18 cores collected. The 1994 Record of Decision cleanup requirement is 1.0 mg/kg; two more goals (0.4 and 0.05 mg/kg t-PCBs) also were identified. Average surface sedimentation requirements to meet the three goals were 1.4 +/- 3.7, 11 +/- 4.2, and 33 +/- 11 cm, respectively. Using the age dating results, the average recovery dates to meet these goals were 2000.6 +/- 2.7, 2007.4 +/- 3.5, and 2022.7 +/- 11 yr, respectively. (The 95% prediction limits for these values also are provided.) Despite the reduction in surface sediment PCB concentrations, PCB concentrations measured in largemouth bass and hybrid bass filets continue to exceed the 2.0 mg/kg FDA fish tolerance level.

Water-quality conditions at selected landfills in Mecklenburg County, North Carolina, 1986-92

USGS Publications Warehouse

Ferrell, G.M.; Smith, D.G.

1995-01-01

Water-quality conditions at five municipal landfills in Mecklenburg County, North Carolina, were studied during 1986-92. Analytical results of water samples from monitoring wells and streams at and near the landfills were used to evaluate effects of leachate on surface and ground water. Ground-water levels at monitoring wells were used to determine directions of ground-water flow at the landfills. Data from previous studies were used for analysis of temporal trends in selected water-quality properties and chemical constituents. Effects of leachate, such as large biochemical- and chemical-oxygen demands, generally were evident in small streams originating within the landfills, whereas effects of leachate generally were not evident in most of the larger streams. In larger streams, surface-water quality upstream and downstream from most of the landfills was similar. However, the chemical quality of water in Irwin Creek appears to have been affected by the Statesville Road landfill. Concentrations of several constituents indicative of leachate were larger in samples collected from Irwin Creek downstream from the Statesville Road landfill than in samples collected from Irwin Creek upstream from the landfill. The effect of leachate on ground-water quality generally was largest in water from wells adjacent to waste-disposal cells. Concentrations of most constituents considered indicative of leachate generally were smaller with increasing distance from waste-disposal cells. Water samples from offsite wells generally indicated no effect or very small effects of leachate. Action levels designated by the Mecklenburg County Engineering Department and maximum contaminant levels established by the U.S. Environmental Protection Agency were exceeded in some samples from the landfills. Ground-water samples exceeded action levels and maximum contaminant levels more commonly than surface-water samples. Iron and manganese were the constituents that most commonly exceeded action levels in water samples from the landfills. Synthetic organic compounds were detected more commonly and in larger concentrations in ground-water samples than in surface-water samples. Concentrations of synthetic organic compounds detected in water samples from monitoring sites at the landfills generally were much less than maximum contaminant levels. However, concentrations of some chlorinated organic compounds exceeded maximum contaminant levels in samples from several monitoring wells at the Harrisburg Road and York Road landfills. Trend analysis indicated statistically significant temporal changes in concentrations of selected water-quality constituents and properties at some of the monitoring sites. Trends detected for the Holbrooks Road and Statesville Road landfills generally indicated an improvement in water quality and a decrease in effects of leachate at most monitoring sites at these landfills from 1979 to 1992. Water-quality trends detected for monitoring sites at the Harrisburg Road and York Road landfills, the largest landfills in the study, differed in magnitude and direction. Upward trends generally were detected for sites near recently closed waste-disposal cells, whereas downward trends generally were detected for sites near older waste-disposal cells. Temporal trends in water quality generally reflected changes in degradation processes associated with the aging of landfill wastes.

Capabilities of the Materials Contamination Team at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Burns, H. D.; Finckenor, M. M.; Boothe, R. E.; Albyn, K. C.; Finchum, C. A.

2003-01-01

The Materials Contamination Team of the Environmental Effects Group, Materials, Processes, and Manufacturing Department, has been recognized for its contribution to space flight, including space transportation, space science and flight projects, such as the reusable solid rocket motor, Chandra X-Ray Observatory, and the International Space Station. The Materials Contamination Team s realm of responsibility encompasses all phases of hardware development including design, manufacturing, assembly, test, transportation, launch-site processing, on-orbit exposure, return, and refurbishment if required. Contamination is a concern in the Space Shuttle with sensitivity bondlines and reactive fluid (liquid oxygen) compatibility as well as for sensitive optics, particularly spacecraft such as Hubble Space Telescope and Chandra X-Ray Observatory. The Materials Contamination Team has a variety of facilities and instrumentation capable of contaminant detection identification, and monitoring. The team addresses material applications dealing with environments, including production facilities, clean rooms, and on-orbit exposure. The team of engineers and technicians also develop and evaluates new surface cleanliness inspection technologies. Databases are maintained by the team for proces! materials as well as outgassing and optical compatibility test results for specific environments.