Fate of Fumonisin B1 in Naturally Contaminated Corn during Ethanol Fermentation

PubMed Central

Bothast, R. J.; Bennett, G. A.; Vancauwenberge, J. E.; Richard, J. L.

1992-01-01

Two lots of corn naturally contaminated with fumonisin B1 (15 and 36 ppm) and a control lot (no fumonisin B1 detected) were used as substrates for ethanol production in replicate 8.5-liter yeast fermentations. Ethanol yields were 8.8% for both the control and low-fumonisin corn, while the high-fumonisin corn contained less starch and produced 7.2% ethanol. Little degradation of fumonisin occurred during fermentation, and most was recovered in the distillers' grains, thin stillage, and distillers' solubles fractions. No toxin was detected in the distilled alcohol or centrifuge solids. Ethanol fermentation of fumonisin-contaminated corn coupled with effective detoxification of distillers' grains and aqueous stillage is suggested as a practical process strategy for salvaging contaminated corn. PMID:16348623

High Hand Contamination Rates During Norovirus Outbreaks in Long-Term Care Facilities.

PubMed

Park, Geun Woo; Williamson, Keenan J; DeBess, Emilio; Cieslak, Paul R; Gregoricus, Nicole; De Nardo, Elizabeth; Fricker, Christopher; Costantini, Verónica; Vinjé, Jan

2018-02-01

We examined norovirus contamination on hands of ill patients during 12 norovirus outbreaks in 12 long-term care facilities (LTCFs). The higher frequency and norovirus titers on hands of residents compared to hands of heathcare workers highlights the importance of adhering to appropriate hand hygiene practices during norovirus outbreaks in LTCFs. Infect Control Hosp Epidemiol 2018;39:219-221.

Garment selection for cleanrooms and controlled environments for spacecraft

NASA Astrophysics Data System (ADS)

Watts, Ethel J.

Strict contamination control practices are exercised throughout the lifetime of a spacecraft in order to satisfy the performance requirements of the system. Spacecraft materials are carefully selected to have low outgassing values and particulate deposition. Parts are cleaned, and the vehicle is assembled in cleanrooms and work stations having controlled environments. Specifications are examined which govern the selection of special items of clothing designed to protect spacecraft from contaminants released by personnel and by garments. Special clothing includes coveralls, footwear, and head/face covers. Garments appropriate for both hazardous (meltproof as well as flame resistant), and nonhazardous operations are described.

Critical control points for avian influenza A H5N1 in live bird markets in low resource settings.

PubMed

Samaan, Gina; Gultom, Anita; Indriani, Risa; Lokuge, Kamalini; Kelly, Paul M

2011-06-01

Live bird markets can become contaminated with and become a source of transmission for avian influenza viruses including the highly pathogenic H5N1 strain. Many countries affected by the H5N1-virus have limited resources for programs in environmental health, sanitation and disease control in live bird markets. This study proposes five critical control points (CCPs) to reduce the risk of H5N1-virus contamination in markets in low resource settings. The CCPs were developed based on three surveys conducted in Indonesia: a cross-sectional survey in 119 markets, a knowledge, attitudes and practice survey in 3 markets and a microbiological survey in 83 markets. These surveys assessed poultry workflow, market infrastructure, hygiene and regulatory practices and microbiological contamination with the H5N1-virus. The five CCPs identified were (1) reducing risk of receiving infected birds into the market, (2) reducing the risk of virus spread between different bird flocks in holding cages, (3) reducing surface contamination by isolating slaughter processes from other poultry-related processes, (4) minimizing the potential for contamination during evisceration of carcasses and (5) reducing the risk of surface contamination in the sale zone of the market. To be relevant for low resource settings, the CCPs do not necessitate large infrastructure changes. The CCPs are suited for markets that slaughter poultry and have capacity for daily disposal and removal of solid waste from the market. However, it is envisaged that the CCPs can be adapted for the development of risk-based programs in various settings. Copyright © 2011 Elsevier B.V. All rights reserved.

Application and assessment of a regular environmental monitoring of the antineoplastic drug contamination level in pharmacies - the MEWIP project.

PubMed

Kiffmeyer, Thekla K; Tuerk, Jochen; Hahn, Moritz; Stuetzer, Hartmut; Hadtstein, Claudia; Heinemann, André; Eickmann, Udo

2013-05-01

A large-scale study was carried out in order to determine the contamination level of antineoplastic drugs in pharmacies and to investigate the suitability and effects of wipe sample monitoring at regular intervals. A specific study design was developed. The 130 participating pharmacies were divided into a study and a control group, carrying out five and two wipe sampling cycles, respectively. The work practice was analyzed using questionnaires to identify factors that influence the contamination level. From 1269 wipe samples, 774 (61%) were contaminated with at least one of the analyzed cytotoxic drugs: cyclophosphamide, docetaxel, etoposide, 5-fluorouracil, gemcitabine, ifosfamide, methotrexate, and paclitaxel. A significant decrease of the contamination with cyclophosphamide and 5-fluorouracil was observed in the study group. The Monitoring-Effect Study of Wipe Sampling in Pharmacies method has proven to be a reliable and affordable tool for contamination control. Based on the 90th percentile of the contamination values, a substance-independent performance-based guidance value of 0.1ng cm(-2) has been derived.

Alien invasive species and international trade

USDA-ARS?s Scientific Manuscript database

Emergency control measures for invasive species often rely on use of pesticides and other destructive practices. Public concern about pesticide contamination of the ground water and the environment has lead to increased restrictions on the use of pesticides for control of many destructive invasive ...

Biologically Based Methods for Control of Fumonisin-Producing Fusarium Species and Reduction of the Fumonisins

PubMed Central

Alberts, Johanna F.; van Zyl, Willem H.; Gelderblom, Wentzel C. A.

2016-01-01

Infection by the fumonisin-producing Fusarium spp. and subsequent fumonisin contamination of maize adversely affect international trade and economy with deleterious effects on human and animal health. In developed countries high standards of the major food suppliers and retailers are upheld and regulatory controls deter the importation and local marketing of fumonisin-contaminated food products. In developing countries regulatory measures are either lacking or poorly enforced, due to food insecurity, resulting in an increased mycotoxin exposure. The lack and poor accessibility of effective and environmentally safe control methods have led to an increased interest in practical and biological alternatives to reduce fumonisin intake. These include the application of natural resources, including plants, microbial cultures, genetic material thereof, or clay minerals pre- and post-harvest. Pre-harvest approaches include breeding for resistant maize cultivars, introduction of biocontrol microorganisms, application of phenolic plant extracts, and expression of antifungal proteins and fumonisin degrading enzymes in transgenic maize cultivars. Post-harvest approaches include the removal of fumonisins by natural clay adsorbents and enzymatic degradation of fumonisins through decarboxylation and deamination by recombinant carboxylesterase and aminotransferase enzymes. Although, the knowledge base on biological control methods has expanded, only a limited number of authorized decontamination products and methods are commercially available. As many studies detailed the use of natural compounds in vitro, concepts in reducing fumonisin contamination should be developed further for application in planta and in the field pre-harvest, post-harvest, and during storage and food-processing. In developed countries an integrated approach, involving good agricultural management practices, hazard analysis and critical control point (HACCP) production, and storage management, together with selected biologically based treatments, mild chemical and physical treatments could reduce fumonisin contamination effectively. In rural subsistence farming communities, simple, practical, and culturally acceptable hand-sorting, maize kernel washing, and dehulling intervention methods proved to be effective as a last line of defense for reducing fumonisin exposure. Biologically based methods for control of fumonisin-producing Fusarium spp. and decontamination of the fumonisins could have potential commercial application, while simple and practical intervention strategies could also impact positively on food safety and security, especially in rural populations reliant on maize as a dietary staple. PMID:27199904

Bacterial contamination of stethoscopes used by health workers: public health implications.

PubMed

Uneke, Chigozie J; Ogbonna, Annayo; Oyibo, Patrick G; Onu, Christian M

2010-08-04

This study was designed to assess both the potential for bacterial transmission by stethoscopes used by health-care workers in Nigeria and the implications for patient safety and control of hospital-acquired infections. A structured questionnaire was administered to health workers and the surface of the diaphragm of their stethoscopes swabbed for bacteriological analysis using standard techniques. Of the 107 stethoscopes surveyed, 84 (79%) were contaminated with bacteria; 59 (81%) of the contaminated stethoscopes belonged to physicians and 25 (74%) were from other health workers. Isolates included Staphylococcus aureus (54%), Pseudomonas aeruginosa (19%), Enterococcus faecalis (14%), and Escherichia coli (13%). All stethoscopes that had never been cleaned were contaminated while lower levels of contamination were found on those cleaned one week or less before the survey (chi(2) = 22.4, P < .05). Contamination was significantly higher on stethoscopes cleaned with only water (100%) compared to those cleaned with alcohol (49%) (chi(2) = 30.17, P < .05). Significantly fewer (9%) stethoscopes from health workers who washed their hands after seeing each patient were contaminated when compared with the instruments (86%) of those who did not practice hand washing (chi(2) = 23.79, P < .05). E. coli showed the highest antibiotic resistance, while S. aureus showed the highest antibiotic susceptibility. Strict adherence to stethoscope disinfection practices by health workers can minimize cross-contamination and ensure improved patient safety in hospital environments.

Compliance With Recommended Food Safety Practices in Television Cooking Shows.

PubMed

Cohen, Nancy L; Olson, Rita Brennan

Examine compliance with recommended food safety practices in television cooking shows. Using a tool based on the Massachusetts Food Establishment Inspection Report, raters examined 39 episodes from 10 television cooking shows. Chefs demonstrated conformance with good retail practices for proper use and storage of utensils in 78% of episodes; preventing contamination (62%), and fingernail care (82%). However, 50% to 88% of episodes were found to be out of compliance with other personal hygiene practices, proper use of gloves and barriers (85% to 100%), and maintaining proper time and temperature controls (93%). Over 90% failed to conform to recommendations regarding preventing contamination through wiping cloths and washing produce. In only 13% of episodes were food safety practices mentioned. There appears to be little attention to food safety during most cooking shows. Celebrity and competing chefs have the opportunity to model and teach good food safety practices for millions of viewers. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Bacteriophages as Biological Control Agents of Enteric Bacteria Contaminating Edible Oysters.

PubMed

Le, Tuan Son; Southgate, Paul C; O'Connor, Wayne; Poole, Sue; Kurtbӧke, D Ipek

2018-05-01

Bacterial contamination on seafood resulting from unhygienic food-handling practices causes foodborne diseases and significant revenue losses. Moreover, control measures are complicated by a high prevalence of antibiotic-resistant bacteria. Alternative measures such as the phage therapy, therefore, is considered as an environmental and consumer-friendly biological control strategy for controlling such bacterial contamination. In this study, we determined the effectiveness of a bacteriophage cocktail in controlling E. coli strains [JM 109, ATCC 13706 and the, extended spectrum beta-lactamase resistant strain (ATCC BAA 196)] and S. enterica subsp. enterica (ATCC 13311) as single and combined contaminants of the edible oysters. Five different E. coli-specific phages (belonging to the Siphoviridae family) and a Salmonella phage (belonging to the Tectiviridae family) were successfully isolated from sewage water samples taken from a local sewage treatment plan in the Sunshine Coast region of Australia. Phage treatments applied to the pathogens when they were presented on the oysters as either single or combined hosts, resulted in significant decrease of the number of these bacteria on edible oysters. Results obtained indicated that bacteriophages could have beneficial applications in oyster-processing plants in controlling pathogenic bacterial infestations. This study thus contributes towards ongoing international efforts into the effective use of bacteriophages for biological control purposes.

21 CFR 1271.260 - Storage.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Storage. 1271.260 Section 1271.260 Food and Drugs... TISSUE-BASED PRODUCTS Current Good Tissue Practice § 1271.260 Storage. (a) Control of storage areas. You must control your storage areas and stock rooms to prevent: (1) Mix-ups, contamination, and cross...

21 CFR 1271.260 - Storage.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Storage. 1271.260 Section 1271.260 Food and Drugs... TISSUE-BASED PRODUCTS Current Good Tissue Practice § 1271.260 Storage. (a) Control of storage areas. You must control your storage areas and stock rooms to prevent: (1) Mix-ups, contamination, and cross...

21 CFR 1271.260 - Storage.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Storage. 1271.260 Section 1271.260 Food and Drugs... TISSUE-BASED PRODUCTS Current Good Tissue Practice § 1271.260 Storage. (a) Control of storage areas. You must control your storage areas and stock rooms to prevent: (1) Mix-ups, contamination, and cross...

21 CFR 1271.260 - Storage.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Storage. 1271.260 Section 1271.260 Food and Drugs... TISSUE-BASED PRODUCTS Current Good Tissue Practice § 1271.260 Storage. (a) Control of storage areas. You must control your storage areas and stock rooms to prevent: (1) Mix-ups, contamination, and cross...

Evaluation of Bacterial Contamination of Clipper Blades in Small Animal Private Practice.

PubMed

Mount, Rebecca; Schick, Anthea E; Lewis, Thomas P; Newton, Heide M

2016-01-01

Nosocomial infections are a growing concern in veterinary hospitals, and identifying fomites is imperative to reducing the risk of pathogen transmission. In veterinary medicine, shaving of hair is necessary prior to many procedures. Contaminated clipper blades have been cited as potential fomites involved in the transmission of pathogens in veterinary and human medicine. The primary goal of this study was to evaluate bacterial contamination of clipper blades in veterinary practices. A secondary goal was to assess whether there was an association between bacterial contamination of clipper blades and clipper blade cleaning solutions, clipper blade cleaning protocols, clipper blade storage, and type of practice. Sixty clipper blades from 60 different practices were cultured. Information regarding blade cleaning solutions, protocols, and storage was collected from each practice. Fifty-one percent (31/60) of clipper blades sampled were contaminated with bacteria. Category of cleaning solutions had a significant association with bacterial contamination (P < 0.02). Cleaning frequency (P = 0.55), storage location (P = 0.26), and practice type (P = 0.06) had no significant association with bacterial contamination. This study documented bacterial contamination of clipper blades in veterinary practices, and clipper blades should be considered potential fomites.

Evaluation of laminar flow control systems for subsonic commercial transport aircraft: Executive summary

NASA Technical Reports Server (NTRS)

Pearce, W. E.

1982-01-01

An evaluation was made of laminar flow control (LFC) system concepts for subsonic commercial transport aircraft. Configuration design studies, performance analyses, fabrication development, structural testing, wind tunnel testing, and contamination-avoidance techniques were included. As a result of trade studies, a configuration with LFC on the upper wing surface only, utilizing an electron beam-perforated suction surface, and employing a retractable high-lift shield for contamination avoidance, was selected as the most practical LFC system. The LFC aircraft was then compared with an advanced turbulent aircraft designed for the same mission. This comparison indicated significant fuel savings.

Practical Cleanroom Operations Constraints

NASA Technical Reports Server (NTRS)

Hughes, David; Ginyard, Amani

2007-01-01

This viewgraph presentation reviews the GSFC Cleanroom Facility i.e., Spacecraft Systems Development and Integration Facility (SSDIF) with particular interest in its use during the development of the Wide Field Camera 3 (WFC3). The SSDIF is described and a diagram of the SSDIF is shown. A Constraint Table was created for consistency within Contamination Control Team. This table is shown. Another table that shows the activities that were allowed during the integration under given WFC3 condition and activity location is presented. Three decision trees are shown for different phases of the work: (1) Hardware Relocation, Hardware Work, and Contamination Control Operations.

Prevention of DNA contamination during forensic medical examinations in a clinical forensic medical service: A best practice implementation project.

PubMed

Lutz, Tasha

2015-01-01

Contamination of forensic specimens can have significant and detrimental effects on cases presented in court. In 2010 a wrongful conviction in Australia resulted in an inquiry with 25 recommendations to minimize the risk of DNA contamination of forensic specimens. DNA decontamination practices in a clinical forensic medical service currently attempt to comply with these recommendations. Evaluation of these practices has not been undertaken. The aim of this project was to audit the current DNA decontamination practices of forensic medical and nursing examiners in the forensic medical examination process and implement changes based on the audit findings. A re-audit following implementation would be undertaken to identify change and inform further research. The Joanna Briggs Institute's Practical Application of Clinical Evidence System and Getting Research into Practice were used as the audit tool in this project. A baseline audit was conducted; analysis of this audit process was then undertaken. Following education and awareness training targeted at clinicians, a re-audit was completed. There were a total of 24 audit criteria; the baseline audit reflected 20 of these criteria had 100% compliance. The remaining 4 audit criteria demonstrated compliance between 65% and 90%. Education and awareness training resulted in improved compliance in 2 of the 4 audit criteria, with the remaining 2 having unchanged compliance. The findings demonstrated that education and raising awareness can improve clinical practice; however there are also external factors outside the control of the clinicians that influence compliance with best practice.

Escherichia coli O157:H7 in beef cattle: on farm contamination and pre-slaughter control methods.

PubMed

Soon, J M; Chadd, S A; Baines, R N

2011-12-01

This paper addresses food safety in beef cattle production, with particular emphasis on factors that affect the prevalence of Escherichia coli O157:H7 in beef cattle and on control methods that have been investigated. Product recalls and foodborne diseases due to this organism continue to occur even though control measures have been under investigation for over 20 years. Most meatborne outbreaks are due to improper food handling practices and consumption of undercooked meat. However, the majority of pathogenic bacteria that can spread at slaughter by cross-contamination can be traced back to the farm rather than originating from the slaughter plant. This would ideally require the adoption of rigorous on-farm intervention strategies to mitigate risks at the farm level. On-farm strategies to control and reduce E. coli O157:H7 at the farm level will reduce the risk of carcass contamination at slaughter and processing facilities although they will not eliminate E. coli O157:H7. The most successful strategy for reducing the risk of contamination of beef and beef products will involve the implementation of both pre- and post-harvest measures.

Importance of good manufacturing practices in microbiological monitoring in processing human tissues for transplant.

PubMed

Pianigiani, Elisa; Ierardi, Francesca; Fimiani, Michele

2013-12-01

Skin allografts represent an important therapeutic resource in the treatment of severe skin loss. The risk associated with application of processed tissues in humans is very low, however, human material always carries the risk of disease transmission. To minimise the risk of contamination of grafts, processing is carried out in clean rooms where air quality is monitored. Procedures and quality control tests are performed to standardise the production process and to guarantee the final product for human use. Since we only validate and distribute aseptic tissues, we conducted a study to determine what type of quality controls for skin processing are the most suitable for detecting processing errors and intercurrent contamination, and for faithfully mapping the process without unduly increasing production costs. Two different methods for quality control were statistically compared using the Fisher exact test. On the basis of the current study we selected our quality control procedure based on pre- and post-processing tissue controls, operator and environmental controls. Evaluation of the predictability of our control methods showed that tissue control was the most reliable method of revealing microbial contamination of grafts. We obtained 100 % sensitivity by doubling tissue controls, while maintaining high specificity (77 %).

An evaluation of the infection control potential of a UV clinical podiatry unit.

PubMed

Humphreys, Paul N; Davies, Chris S; Rout, Simon

2014-02-28

Infection control is a key issue in podiatry as it is in all forms of clinical practice. Airborne contamination may be particularly important in podiatry due to the generation of particulates during treatment. Consequently, technologies that prevent contamination in podiatry settings may have a useful role. The aims of this investigation were twofold, firstly to determine the ability of a UV cabinet to protect instruments from airborne contamination and secondly to determine its ability to remove microbes from contaminated surfaces and instruments. A UV instrument cabinet was installed in a University podiatry suite. Impact samplers and standard microbiological techniques were used to determine the nature and extent of microbial airborne contamination. Sterile filters were used to determine the ability of the UV cabinet to protect exposed surfaces. Artificially contaminated instruments were used to determine the ability of the cabinet to remove microbial contamination. Airborne bacterial contamination was dominated by Gram positive cocci including Staphylococcus aureus. Airborne fungal levels were much lower than those observed for bacteria. The UV cabinet significantly reduced (p < 0.05) the observed levels of airborne contamination. When challenged with contaminated instruments the cabinet was able to reduce microbial levels by between 60% to 100% with more complex instruments e.g. clippers, remaining contaminated. Bacterial airborne contamination is a potential infection risk in podiatry settings due to the presence of S. aureus. The use of a UV instrument cabinet can reduce the risk of contamination by airborne microbes. The UV cabinet tested was unable to decontaminate instruments and as such could pose an infection risk if misused.

An evaluation of the infection control potential of a UV clinical podiatry unit

PubMed Central

2014-01-01

Background Infection control is a key issue in podiatry as it is in all forms of clinical practice. Airborne contamination may be particularly important in podiatry due to the generation of particulates during treatment. Consequently, technologies that prevent contamination in podiatry settings may have a useful role. The aims of this investigation were twofold, firstly to determine the ability of a UV cabinet to protect instruments from airborne contamination and secondly to determine its ability to remove microbes from contaminated surfaces and instruments. Method A UV instrument cabinet was installed in a University podiatry suite. Impact samplers and standard microbiological techniques were used to determine the nature and extent of microbial airborne contamination. Sterile filters were used to determine the ability of the UV cabinet to protect exposed surfaces. Artificially contaminated instruments were used to determine the ability of the cabinet to remove microbial contamination. Results Airborne bacterial contamination was dominated by Gram positive cocci including Staphylococcus aureus. Airborne fungal levels were much lower than those observed for bacteria. The UV cabinet significantly reduced (p < 0.05) the observed levels of airborne contamination. When challenged with contaminated instruments the cabinet was able to reduce microbial levels by between 60% to 100% with more complex instruments e.g. clippers, remaining contaminated. Conclusions Bacterial airborne contamination is a potential infection risk in podiatry settings due to the presence of S. aureus. The use of a UV instrument cabinet can reduce the risk of contamination by airborne microbes. The UV cabinet tested was unable to decontaminate instruments and as such could pose an infection risk if misused. PMID:24576315

[Control of enterohemorrhagic Escherichia coli (EHEC) in cattle].

PubMed

Mercado, Elsa C

2006-01-01

Cattle are recognized as the major reservoir of STEC and the source of infection for human beings. Until recently, intervention strategies to decrease the contamination of meat products have been focused on the slaughter plant with the application of practices to reduce the contamination and proliferation of STEC. This has now changed following the development of intervention strategies in the farm. This could be one of the most important points of intervention to lower the incidence of human infection. Vaccines, probiotics, bacteriophages, and changes in production practices may be useful as strategies to control EHEC in the cattle. The application of such intervention measures could be difficult due to the fact that this zoonotic agent rarely causes disease in bovines. The HUS is endemic in Argentina, and the factors leading to this epidemiological situation remain unknown. However, intervention strategies undoubtedly will contribute to reduce the incidence of this zoonosis.

Demonstration/Validation of a Surface Cleaning Control Practice to Mitigate Storm Water Metal Contaminants

DTIC Science & Technology

2014-04-01

added to a pre- weighed 125-ml low density polyethylene (LDPE) bottle. The particles were digested with 1.0 ml of concentrated trace metal grade (TMG...consideration to ensure completion of operations.   33 9. REFERENCES Breault, R. F., K. P. Smith, and J. R. Sorenson. 2005. “ Residential Street...of the Contaminants and Toxicity Associated with Particles in Stormwater Runoff.” Caltrans CTSW-RT-03-059.73.15. California Department of

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.

76 FR 29767 - Preventive Controls for Registered Human Food and Animal Food/Feed Facilities; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-23

... associated with specific types of food or specific methods of manufacturing, processing, packing, or holding... specific methods of manufacturing, processing, packing, or holding food. In particular, we welcome input on... controls (e.g., procedures and practices utilized to minimize the risk of contamination) for human food and...

A study of visual and blood contamination on reprocessed endodontic files from general dental practice.

PubMed

Letters, S; Smith, A J; McHugh, S; Bagg, J

2005-10-22

This study examined methods used for reprocessing endodontic instruments in general dental practice and determined the degree of residual visual contamination and blood contamination on 250 reprocessed files collected from 25 general dental practices. A questionnaire was administered to 25 general dental practitioners to obtain information on the re-processing of used endodontic files. Ten files which had been used and reprocessed were also collected from each practice. These were examined visually under a dissecting light microscope for residual contamination and then tested for blood deposits using the Kastle-Meyer test. Nineteen of the 25 practices used stainless steel hand files. No practitioners used endodontic files as single use devices. Ninety-two per cent of the practitioners discarded and replaced files when they were bent or damaged. Several decontamination methods were reported. The two combinations employed most frequently were manual cleaning and autoclaving or manual cleaning, followed by ultrasonic cleaning and autoclaving. Of the 250 files, 75% showed some degree of visual contamination and seven percent tested positive for residual blood. Blood contaminated files were significantly more heavily contaminated when examined visually. Large variations were found in residual contamination of files collected from practices using the same methods of decontamination. While all practitioners re-used endodontic files, the variations in decontamination methods reported indicate a lack of clarity on best practice. This study demonstrates that endodontic files are not reliably decontaminated by methods currently employed in dental practice.

78 FR 37505 - International Standard-Setting Activities

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-21

... Code of Practice for Weed Control to Prevent and Reduce Pyrrolizidine Alkaloid Contamination in Food... DEPARTMENT OF AGRICULTURE Food Safety and Inspection Service [Docket No. FSIS-2013-0002] International Standard-Setting Activities AGENCY: Office of Food Safety, USDA. ACTION: Notice. SUMMARY: This...

ALTERNATIVE OXIDANT AND DISINFECTANT TREATMENT STRATEGIES FOR CONTROLLING TRIHALOMETHANE FORMATION

EPA Science Inventory

To comply with the maximum contaminant level (MCL) for total trihalomethanes (TTHM), many utilities have modified their pre-oxidation and disinfection practices by switching to alternative oxidants and disinfectants in place of free chlorine. To evaluate the impact of these chang...

Surveillance of Environmental and Procedural Measures of Infection Control in the Operating Theatre Setting

PubMed Central

Raggi, Alessandra; Sanna, Tiziana; Mazzetti, Magda; Orsi, Alessandra; Zanni, Angela; Farruggia, Patrizia

2017-01-01

The microbiological contamination of operating theatres and the lack of adherence to best practices by surgical staff represent some of the factors affecting Surgical Site Infections (SSIs). The aim of the present study was to assess the microbiological quality of operating settings and the staff compliance to the SSI evidence-based control measures. Ten operating rooms were examined for microbiological contamination of air and surfaces, after cleaning procedures, in “at rest” conditions. Furthermore, 10 surgical operations were monitored to assess staff compliance to the recommended practices. None of the air samples exceeded microbiological reference standards and only six of the 200 surface samples (3.0%) were slightly above recommended levels. Potentially pathogenic bacteria and moulds were never detected. Staff compliance to best practices varied depending on the type of behaviour investigated and the role of the operator. The major not compliant behaviours were: pre-operative skin antisepsis, crowding of the operating room and hand hygiene of the anaesthetist. The good environmental microbiological quality observed is indicative of the efficacy of the cleaning-sanitization procedures adopted. The major critical point was staff compliance to recommended practices. Awareness campaigns are therefore necessary, aimed at improving the organisation of work so as to facilitate compliance to operative protocols. PMID:29283367

Transfusions and kids: the deadly HIV link in Africa.

PubMed

1997-12-01

Contaminated blood transfusions are responsible for a large proportion of HIV infections, particularly among children, in developing countries. Little attention or money has been provided to control these easily preventable transmissions. According to the Centers for Disease Control and Prevention (CDC), basic remedies such as improving blood-screening and blood-banking practices, reducing the number of unnecessary transfusions, and treating malaria with different drugs could play a key role in reducing infection. The quality of blood-screening is often variable and inconsistent across a single country, and a study in Congo found that contaminated blood accounted for 42 percent of HIV infections in children older than one year. Blood transfusions are a common treatment in Africa, where they are used to treat malaria-related anemias. Malaria remains a major health threat in much of the world, and efforts to treat it more effectively will help reduce the number of HIV infections that result from contaminated blood sources.

Outbreak of Salmonella Typhimurium 44 related to egg consumption.

PubMed

Dyda, Amalie; Hundy, Rebecca; Moffatt, Cameron R M; Cameron, Scott

2009-12-01

ACT Health investigated an outbreak of gastroenteritis associated with a local restaurant in December 2008. The infecting agent was Salmonella serotype Typhimurium phage type 44. A case control study was conducted to identify the source of infection. A total of 22 cases and 9 controls were recruited to take part in the study. Both poached eggs (odds ratio [OR] 42.00) and hollandaise sauce (OR 19.00) had elevated odds ratios that were statistically significant. The major limitation of the study was the small sample size and small number of controls. Despite this, a strong association with illness and consumption of eggs and hollandaise sauce was detected and this was further supported by environmental evidence. The investigation concluded that the cause of the outbreak was putatively contaminated eggs, either on their own or as an ingredient used in hollandaise sauce. The investigation and control measures led to an improvement in hygiene practices at the restaurant and contributed to the voluntary recall of the contaminated batch of eggs from the Australian Capital Territory. The results of the study also build upon other evidence that egg-related salmonellosis is now common in Australia and attention to commercial practices at production and processing is overdue.

[Microbiological verification of a self control plan for a hospital food service].

PubMed

Torre, I; Pennino, F; Crispino, M

2006-01-01

During the past years, it has been an increment of food related infectious diseases. In order to avoid micro biological food contamination, adherence to good manufacturing is required through control measures of food safety practices. Updated national and European regulations underline the need to apply the HACCP system, overcoming the old concept of sample control on the end user product. This work shows results of microbiological controls made along the whole productive chain. Measurements are made using biomolecular techniques (PFGE) in order to assess the management of the micro biological risk of the self control plan applied to a hospital food service of Naples. The use of the PFGE applied on some micro-organisms gram negative potentially pathogen, underlines the circulation, continued in time, of these micro-organisms within the cooking area. In addition, cross contamination between several matrixes of samples has been detected.

Evaluation of laminar flow control systems concepts for subsonic commercial transport aircraft

NASA Technical Reports Server (NTRS)

Pearce, W. E.

1983-01-01

An evaluation was made of laminar flow control (LFC) system concepts for subsonic commercial transport aircraft. Configuration design studies, performance analyses, fabrication development, structural testing, wind tunnel testing, and contamination-avoidance techniques were included. As a result of trade studies, a configuration with LFC on the upper wing surface only, utilizing an electron beam-perforated suction surface, and employing a retractable high-lift shield for contamination avoidance, was selected as the most practical LFC system. The LFC aircraft was then compared with an advanced turbulent aircraft designed for the same mission. This comparison indicated significant fuel savings and reduced direct operating cost benefits would result from using LFC.

Variation in Quarters Dispositions A Force Protection and Readiness Issue Explanations and Control Method

DTIC Science & Technology

1999-08-01

information may be crucial for the early identification of any range of potential health Variation in Quarters Rates 28 threats from food contamination to... GMO Physician 309.89 .0000 Over Family Practice 682.06 .0000 Over Aeromed Physician

A flexible framework for process-based hydraulic and water quality modeling of stormwater green infrastructure performance

EPA Science Inventory

Background Models that allow for design considerations of green infrastructure (GI) practices to control stormwater runoff and associated contaminants have received considerable attention in recent years. While popular, generally, the GI models are relatively simplistic. However,...

Challenges for environmental hygiene practices in Australian paramedic-led health care: A brief report.

PubMed

Barr, Nigel; Holmes, Mark; Roiko, Anne; Dunn, Peter; Lord, Bill

2018-06-01

This study explored the self-reported behaviors and perceptions of Australian paramedics in relation to their environmental hygiene practices. A national online survey was conducted with Paramedics Australasia members (N = 417). Participants reported working in ambulances often contaminated with body fluids. Widespread noncompliance with routine and deep cleaning of ambulances, and misunderstandings about environmental hygiene practices were apparent. Improvements to environmental hygiene practices of Australian paramedics are recommended to avoid pathogen transmission and ensure patient safety. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Testing antimicrobial paint efficacy on gypsum wallboard contaminated with Stachybotrys chartarum.

PubMed

Menetrez, M Y; Foarde, K K; Webber, T D; Dean, T R; Betancourt, D A

2008-02-01

The goal of this research was to reduce occupant exposure to indoor mold through the efficacy testing of antimicrobial paints. An accepted method for handling Stachybotrys chartarum-contaminated gypsum wallboard (GWB) is removal and replacement. This practice is also recommended for water-damaged or mold-contaminated GWB but is not always followed completely. The efficacy of antimicrobial paints to eliminate or control mold regrowth on surfaces can be tested easily on nonporous surfaces. The testing of antimicrobial efficacy on porous surfaces found in the indoor environment, such as gypsum wallboard, can be more complicated and prone to incorrect conclusions regarding residual organisms. The mold S. chartarum has been studied for toxin production and its occurrence in water-damaged buildings. Research to control its growth using seven different antimicrobial paints and two commonly used paints on contaminated, common gypsum wallboard was performed in laboratory testing at high relative humidity. The results indicate differences in antimicrobial efficacy for the period of testing, and that proper cleaning and resurfacing of GWB with an antimicrobial paint can be an option in those unique circumstances when removal may not be possible.

Mycotoxin problem in Africa: current status, implications to food safety and health and possible management strategies.

PubMed

Wagacha, J M; Muthomi, J W

2008-05-10

Mycotoxins are toxic secondary metabolites of fungal origin and contaminate agricultural commodities before or under post-harvest conditions. They are mainly produced by fungi in the Aspergillus, Penicillium and Fusarium genera. When ingested, inhaled or absorbed through the skin, mycotoxins will cause lowered performance, sickness or death on humans and animals. Factors that contribute to mycotoxin contamination of food and feed in Africa include environmental, socio-economic and food production. Environmental conditions especially high humidity and temperatures favour fungal proliferation resulting in contamination of food and feed. The socio-economic status of majority of inhabitants of sub-Saharan Africa predisposes them to consumption of mycotoxin contaminated products either directly or at various points in the food chain. The resulting implications include immuno-suppression, impaired growth, various cancers and death depending on the type, period and amount of exposure. A synergistic effect between mycotoxin exposure and some important diseases in the continent such as malaria, kwashiorkor and HIV/AIDS have been suggested. Mycotoxin concerns have grown during the last few decades because of their implications to human and animal health, productivity, economics of their management and trade. This has led to development of maximum tolerated limits for mycotoxins in various countries. Even with the standards in place, the greatest recorded fatal mycotoxin-poisoning outbreak caused by contamination of maize with aflatoxins occurred in Africa in 2004. Pre-harvest practices; time of harvesting; handling of produce during harvesting; moisture levels at harvesting, transportation, marketing and processing; insect damage all contribute to mycotoxin contamination. Possible intervention strategies include good agricultural practices such as early harvesting, proper drying, sanitation, proper storage and insect management among others. Other possible interventions include biological control, chemical control, decontamination, breeding for resistance as well as surveillance and awareness creation. There is need for efficient, cost-effective sampling and analytical methods that can be used for detection analysis of mycotoxins in developing countries.

Aconitum Alkaloid Poisoning Because of Contamination of Herbs by Aconite Roots.

PubMed

Chan, Thomas Y K

2016-01-01

Aconitum alkaloid poisoning can occur after drinking decoction and soup made from non-toxic herbs contaminated by aconite roots. In the present review, the main objective is to describe the clinical features, investigations and possible sources of contamination. A combination of neurological, gastrointestinal and cardiovascular signs and symptoms was seen. Ventricular tachyarrhythmias could occur in 18% of subjects. Yunaconitine and crassicauline A, mainly found in certain aconite roots from Southwest China, are most commonly involved. Herbal residues and unused herbs should first be inspected for gross contamination. On-site inspection at the retailer should exclude accidental mix-up or cross-contamination when handling aconite roots. Samples of prescribed herbs are examined for gross contamination and analysed for the presence of Aconitum alkaloids. Samples of the implicated herb are also collected from the wholesaler for investigation. If post-import contamination is unlikely, the regulatory authorities of the exporting countries should be notified for follow-up actions. It is a challenging task to work out how non-toxic herbs become contaminated by aconite roots. The source control with good agricultural and collection practices and quality assurance must be enhanced. Copyright © 2015 John Wiley & Sons, Ltd.

Identification and Removal of Contaminant Sequences From Ribosomal Gene Databases: Lessons From the Census of Deep Life

PubMed Central

Sheik, Cody S.; Reese, Brandi Kiel; Twing, Katrina I.; Sylvan, Jason B.; Grim, Sharon L.; Schrenk, Matthew O.; Sogin, Mitchell L.; Colwell, Frederick S.

2018-01-01

Earth’s subsurface environment is one of the largest, yet least studied, biomes on Earth, and many questions remain regarding what microorganisms are indigenous to the subsurface. Through the activity of the Census of Deep Life (CoDL) and the Deep Carbon Observatory, an open access 16S ribosomal RNA gene sequence database from diverse subsurface environments has been compiled. However, due to low quantities of biomass in the deep subsurface, the potential for incorporation of contaminants from reagents used during sample collection, processing, and/or sequencing is high. Thus, to understand the ecology of subsurface microorganisms (i.e., the distribution, richness, or survival), it is necessary to minimize, identify, and remove contaminant sequences that will skew the relative abundances of all taxa in the sample. In this meta-analysis, we identify putative contaminants associated with the CoDL dataset, recommend best practices for removing contaminants from samples, and propose a series of best practices for subsurface microbiology sampling. The most abundant putative contaminant genera observed, independent of evenness across samples, were Propionibacterium, Aquabacterium, Ralstonia, and Acinetobacter. While the top five most frequently observed genera were Pseudomonas, Propionibacterium, Acinetobacter, Ralstonia, and Sphingomonas. The majority of the most frequently observed genera (high evenness) were associated with reagent or potential human contamination. Additionally, in DNA extraction blanks, we observed potential archaeal contaminants, including methanogens, which have not been discussed in previous contamination studies. Such contaminants would directly affect the interpretation of subsurface molecular studies, as methanogenesis is an important subsurface biogeochemical process. Utilizing previously identified contaminant genera, we found that ∼27% of the total dataset were identified as contaminant sequences that likely originate from DNA extraction and DNA cleanup methods. Thus, controls must be taken at every step of the collection and processing procedure when working with low biomass environments such as, but not limited to, portions of Earth’s deep subsurface. Taken together, we stress that the CoDL dataset is an incredible resource for the broader research community interested in subsurface life, and steps to remove contamination derived sequences must be taken prior to using this dataset. PMID:29780369

Identification and Removal of Contaminant Sequences From Ribosomal Gene Databases: Lessons From the Census of Deep Life.

PubMed

Sheik, Cody S; Reese, Brandi Kiel; Twing, Katrina I; Sylvan, Jason B; Grim, Sharon L; Schrenk, Matthew O; Sogin, Mitchell L; Colwell, Frederick S

2018-01-01

Earth's subsurface environment is one of the largest, yet least studied, biomes on Earth, and many questions remain regarding what microorganisms are indigenous to the subsurface. Through the activity of the Census of Deep Life (CoDL) and the Deep Carbon Observatory, an open access 16S ribosomal RNA gene sequence database from diverse subsurface environments has been compiled. However, due to low quantities of biomass in the deep subsurface, the potential for incorporation of contaminants from reagents used during sample collection, processing, and/or sequencing is high. Thus, to understand the ecology of subsurface microorganisms (i.e., the distribution, richness, or survival), it is necessary to minimize, identify, and remove contaminant sequences that will skew the relative abundances of all taxa in the sample. In this meta-analysis, we identify putative contaminants associated with the CoDL dataset, recommend best practices for removing contaminants from samples, and propose a series of best practices for subsurface microbiology sampling. The most abundant putative contaminant genera observed, independent of evenness across samples, were Propionibacterium , Aquabacterium , Ralstonia , and Acinetobacter . While the top five most frequently observed genera were Pseudomonas , Propionibacterium , Acinetobacter , Ralstonia , and Sphingomonas . The majority of the most frequently observed genera (high evenness) were associated with reagent or potential human contamination. Additionally, in DNA extraction blanks, we observed potential archaeal contaminants, including methanogens, which have not been discussed in previous contamination studies. Such contaminants would directly affect the interpretation of subsurface molecular studies, as methanogenesis is an important subsurface biogeochemical process. Utilizing previously identified contaminant genera, we found that ∼27% of the total dataset were identified as contaminant sequences that likely originate from DNA extraction and DNA cleanup methods. Thus, controls must be taken at every step of the collection and processing procedure when working with low biomass environments such as, but not limited to, portions of Earth's deep subsurface. Taken together, we stress that the CoDL dataset is an incredible resource for the broader research community interested in subsurface life, and steps to remove contamination derived sequences must be taken prior to using this dataset.

Water contamination in urban south India: household storage practices and their implications for water safety and enteric infections.

PubMed

Brick, Thomas; Primrose, Beryl; Chandrasekhar, R; Roy, Sheela; Muliyil, Jayaprakash; Kang, Gagandeep

2004-10-01

Water contamination, at source and during household storage, is a major cause of enterically transmitted infections in developing countries. This study assessed contamination of the municipal water in a south Indian town, which obtains its water intermittently from a surface lake and by pumping subsurface water from a dry river bed, and monitored microbial contamination during household storage. All samples of the 'treated' municipal water were contaminated when freshly pumped, and on household storage, 25/37 (67%) showed increased contamination during storage periods from 1 to 9 days. Household storage in brass, but not in containers of other materials significantly decreased contamination of water (p = 0.04). This was confirmed in the laboratory by testing water seeded with 10(3) to 10(5) Escherichia coli per 100 ml stored in containers of different materials (p < 0.01). Despite the requirements for provision of safe drinking water in municipal areas, in practice the water supplied in Vellore is contaminated and current household storage practices increase the level of contamination in at least two-thirds of households. The implementation of locally appropriate point-of-use disinfection and safe household storage practices in developing countries is an urgent need to ensure a safe, reliable year-round supply in areas where clean water is not available.

Sustainability policy and effects on practices in the remediation field

NASA Astrophysics Data System (ADS)

Hou, D.; Al-Tabbaa, A.

2012-12-01

Land is not only a critical component of the earth's life support system, but also a precious resource and an important factor of production in economy. However, historical industrial operations have caused a huge stockpile of contaminated land that is only slowly being remediated. After several decades of clean-up efforts, there are still an estimated 294,000 contaminated sites in the US and over 300,000 hectares of potentially contaminated land in the UK. It is imperative to develop technical solutions as well as socioeconomic and political instruments to achieve sustainable restoration of contaminated land. The inclusion of sustainability in decision making provides an opportunity to integrate a wide range of considerations: risk control, brownfield regeneration, carbon footprint, water footprint, renewable energy, etc. This study explores the behavior patterns and driving forces behind sustainable practices in remediation, aiming at advancing our understanding of the fundamental relationships among changing natural and manipulated geological environments, sustainability, and technology choices. A large-scale survey is being conducted in the US and UK to study behaviour and decision making issues from a stakeholder perspective. Historically stakeholder theories have been extensively applied to study organization management issues in the academia. This study intends to apply stakeholder theories to engineering practice and sustainability science studies. Pilot test results found that sustainability considerations are widely adopted and in a wide variety of ways. Site owners and regulators are found to be most influential in the decision making process. There is no lack of incentives to adopt sustainability practices, but various factors, such as lack of resources and cost considerations, are still considered impeding factors. At the time of the 2012 AGU meeting, further results from the survey will be available.

Best infection control practices for intradermal, subcutaneous, and intramuscular needle injections.

PubMed Central

Hutin, Yvan; Hauri, Anja; Chiarello, Linda; Catlin, Mary; Stilwell, Barbara; Ghebrehiwet, Tesfamicael; Garner, Julia

2003-01-01

OBJECTIVE: To draw up evidence-based guidelines to make injections safer. METHODS: A development group summarized evidence-based best practices for preventing injection-associated infections in resource-limited settings. The development process included a breakdown of the WHO reference definition of a safe injection into a list of potentially critical steps, a review of the literature for each of these steps, the formulation of best practices, and the submission of the draft document to peer review. FINDINGS: Eliminating unnecessary injections is the highest priority in preventing injection-associated infections. However, when intradermal, subcutaneous, or intramuscular injections are medically indicated, best infection control practices include the use of sterile injection equipment, the prevention of contamination of injection equipment and medication, the prevention of needle-stick injuries to the provider, and the prevention of access to used needles. CONCLUSION: The availability of best infection control practices for intradermal, subcutaneous, and intramuscular injections will provide a reference for global efforts to achieve the goal of safe and appropriate use of injections. WHO will revise the best practices five years after initial development, i.e. in 2005. PMID:12973641

Control of scabies, skin sores and haematuria in children in the Solomon Islands: another role for ivermectin.

PubMed Central

Lawrence, Gregor; Leafasia, Judson; Sheridan, John; Hills, Susan; Wate, Janet; Wate, Christine; Montgomery, Janet; Pandeya, Nirmala; Purdie, David

2005-01-01

OBJECTIVE: To assess the effects of a 3-year programme aimed at controlling scabies on five small lagoon islands in the Solomon Islands by monitoring scabies, skin sores, streptococcal skin contamination, serology and haematuria in the island children. METHODS: Control was achieved by treating almost all residents of each island once or twice within 2 weeks with ivermectin (160-250 microg/kg), except for children who weighed less than 15 kg and pregnant women, for whom 5% permethrin cream was used. Reintroduction of scabies was controlled by treating returning residents and visitors, whether or not they had evident scabies. FINDINGS: Prevalence of scabies dropped from 25% to less than 1% (P < 0.001); prevalence of sores from 40% to 21% (P < 0.001); streptococcal contamination of the fingers in those with and without sores decreased significantly (P = 0.02 and 0.047, respectively) and anti-DNase B levels decreased (P = 0.002). Both the proportion of children with haematuria and its mean level fell (P = 0.002 and P < 0.001, respectively). No adverse effects of the treatments were seen. CONCLUSION: The results show that ivermectin is an effective and practical agent in the control of scabies and that control reduces the occurrence of streptococcal skin disease and possible signs of renal damage in children. Integrating community-based control of scabies and streptococcal skin disease with planned programmes for controlling filariasis and intestinal nematodes could be both practical and produce great health benefits. PMID:15682247

Monitoring survey of the use patterns and pesticide residues on vegetables in the Niayes zone, Senegal.

PubMed

Diop, Amadou; Diop, Yérim M; Thiaré, Diène D; Cazier, Fabrice; Sarr, Serigne O; Kasprowiak, Amaury; Landy, David; Delattre, François

2016-02-01

The main objective of this work was to determine the impact of pesticide use practices on vegetables contamination in the Niayes zone of Dakar. A preliminary survey involving 200 farmers, showed the application of pesticides belonging to different groups on vegetable crops. Use practices in terms of application intervals and methods, measuring tools and dosage were not in compliance with good agricultural practices. In view of survey results, investigations on vegetable contamination were conducted. Therefore, 175 vegetable samples including cabbage (31 samples), lettuce (88 samples), tomato (57 samples) collected from four sites of the Niayes zone during four campaigns, were analyzed for residues of 21 pesticides, eighteen of which (18) were cited to be used by farmers. The results indicated that 65% of tomato samples, 71% of lettuce and 93% of cabbage contained one or more detectable residues. Among the monitored pesticides dicofol, chlorpyrifos, DDTs, dimethoate, and λ-cyhalothrin were the most predominant, found in at least 35% of samples for each vegetable. The frequencies of pesticide detection were, generally in agreement with the citation frequencies. The results provided important information on vegetable contamination status and pointed an urgent need to control pesticide use. Copyright © 2015. Published by Elsevier Ltd.

Nosocomial Serratia marcescens infections associated with extrinsic contamination of a liquid nonmedicated soap.

PubMed

Sartor, C; Jacomo, V; Duvivier, C; Tissot-Dupont, H; Sambuc, R; Drancourt, M

2000-03-01

To determine the role of nonmedicated soap as a source of Serratia marcescens nosocomial infections (NIs) in hospital units with endemic S marcescens NI and to examine the mechanisms of soap colonization. University-affiliated tertiary-care hospitals. A prospective case-control study and an environmental investigation were performed to assess the relationship between S marcescens NIs in hospital units and S marcescens-contaminated soap. Soap-bottle use and handwashing practices were reviewed. Cultures of healthcare workers' (HCWs) hands were obtained before and after hand washing with soap. 5 of 7 hospital units with S marcescens NIs had soap bottles contaminated with S marcescens, compared to 1 of 14 other units (P=.006). After hand washing with an S marcescens-contaminated soap pump, HCWs' hands were 54 times more likely to be contaminated with S marcescens (P<.001). Extrinsic contamination of a non-medicated liquid soap by S marcescens resulted in handborne transmission of S marcescens NIs by HCWs in our setting. This finding led to the application of strict guidelines for nonmedicated soap use and to the reinforcement of alcoholic hand disinfection.

[Anticholinergic syndrome caused by contaminated herbal tea; acting swiftly to identify the source].

PubMed

Oerlemans, C; de Vries, I; van Riel, A J H P

2017-01-01

Despite good manufacturing practice and quality control, consumer products can become contaminated. In some cases, this can result in severe and life-threatening intoxication with potentially fatal consequences. A 27-year-old man and a 28-year-old pregnant woman presented to the Emergency Department with severe anticholinergic syndrome after using a marshmallow root (Althaea officinalis) herbal remedy, mixed into hot chocolate drink, to reduce symptoms of common cold. After a short stay in Intensive Care, the symptoms diminished and the patients could be released from hospital. The herbs were found to be contaminated with atropine, most probably derived from deadly nightshade (Atropa belladonna). Analyses of the contaminated product indicated that the patients were exposed to 20-200 mg atropine, while a dose of 2 mg is already considered mildly toxic. Consultation of the Dutch National Poisons Information Center resulted in rapid detection of the contamination; close collaboration with the Netherlands Food and Consumer Product Safety Authority and the manufacturer of the product allowed rapid identification of the source of contamination and facilitated the prevention of an epidemic.

Bacterial contamination and stethoscope disinfection practices: a cross-sectional survey of healthcare workers in Karachi, Pakistan.

PubMed

Rao, Danish Ahmed; Aman, Aiysha; Muhammad Mubeen, Syed; Shah, Ahmed

2017-07-01

Stethoscopes routinely used for clinical examination of patients may potentially transfer micro-organisms and cause iatrogenic infections. This study was undertaken to detect the presence of microorganisms on stethoscopes used clinically in hospitals of Karachi, Pakistan and to ascertain the infection control practices of healthcare workers (HCWs). In a cross-sectional study, 118 samples were collected from public and private institutions. Samples were tested for the presence and sensitivity of pathogenic microorganisms. Microorganisms were found on diaphragms of 33/64 (51.6%) and 19/57 (33.3%) stethoscopes in public and private sector hospitals, respectively. Methycillin resistance was identified in all staphylococcally contaminated samples. Only 33 (18%) respondents reported cleaning their stethoscopes regularly. We highlight the need for more and better on-the-job routines for decontaminating stethoscopes among HCWs in Karachi.

Impact of Regular Soap Provision to Primary Schools on Hand Washing and E. coli Hand Contamination among Pupils in Nyanza Province, Kenya: A Cluster-Randomized Trial

PubMed Central

Saboori, Shadi; Greene, Leslie E.; Moe, Christine L.; Freeman, Matthew C.; Caruso, Bethany A.; Akoko, Daniel; Rheingans, Richard D.

2013-01-01

We assessed whether supplying soap to primary schools on a regular basis increased pupil hand washing and decreased Escherichia coli hand contamination. Multiple rounds of structured observations of hand washing events after latrine use were conducted in 60 Kenyan schools, and hand rinse samples were collected one time in a subset of schools. The proportion of pupils observed practicing hand washing with soap (HWWS) events was significantly higher in schools that received a soap provision intervention (32%) and schools that received soap and latrine cleaning materials (38%) compared with controls (3%). Girls and boys had similar hand washing rates. There were non-significant reductions in E. coli contamination among intervention school pupils compared with controls. Removing the barrier of soap procurement can significantly increase availability of soap and hand washing among pupils; however, we discuss limitations in the enabling policy and institutional environment that may have prevented reaching desired levels of HWWS. PMID:23939707

Impact of regular soap provision to primary schools on hand washing and E. coli hand contamination among pupils in Nyanza Province, Kenya: a cluster-randomized trial.

PubMed

Saboori, Shadi; Greene, Leslie E; Moe, Christine L; Freeman, Matthew C; Caruso, Bethany A; Akoko, Daniel; Rheingans, Richard D

2013-10-01

We assessed whether supplying soap to primary schools on a regular basis increased pupil hand washing and decreased Escherichia coli hand contamination. Multiple rounds of structured observations of hand washing events after latrine use were conducted in 60 Kenyan schools, and hand rinse samples were collected one time in a subset of schools. The proportion of pupils observed practicing hand washing with soap (HWWS) events was significantly higher in schools that received a soap provision intervention (32%) and schools that received soap and latrine cleaning materials (38%) compared with controls (3%). Girls and boys had similar hand washing rates. There were non-significant reductions in E. coli contamination among intervention school pupils compared with controls. Removing the barrier of soap procurement can significantly increase availability of soap and hand washing among pupils; however, we discuss limitations in the enabling policy and institutional environment that may have prevented reaching desired levels of HWWS.

Practical measures for reducing the risk of environmental contamination in shale energy production.

PubMed

Ziemkiewicz, Paul; Quaranta, John D; McCawley, Michael

2014-07-01

Gas recovery from shale formations has been made possible by advances in horizontal drilling and hydraulic fracturing technology. Rapid adoption of these methods has created a surge in natural gas production in the United States and increased public concern about its environmental and human health effects. We surveyed the environmental literature relevant to shale gas development and studied over fifteen well sites and impoundments in West Virginia to evaluate pollution caused by air emissions, light and noise during drilling. Our study also characterized liquid and solid waste streams generated by drilling and hydraulic fracturing and evaluated the integrity of impoundments used to store fluids produced by hydraulic fracturing. While most shale gas wells are completed with little or no environmental contamination, we found that many of the problems associated with shale gas development resulted from inattention to accepted engineering practices such as impoundment construction, improper liner installation and a lack of institutional controls. Recommendations are provided based on the literature and our field studies. They will address not all but a great many of the deficiencies that result in environmental release of contaminants from shale gas development. We also identified areas where new technologies are needed to fully address contaminant releases to air and water.

Fecal contamination of drinking water in Kericho District, Western Kenya: role of source and household water handling and hygiene practices.

PubMed

Too, Johana Kiplagat; Kipkemboi Sang, Willy; Ng'ang'a, Zipporah; Ngayo, Musa Otieno

2016-08-01

Inadequate protection of water sources, and poor household hygienic and handling practices have exacerbated fecal water contamination in Kenya. This study evaluated the rate and correlates of thermotolerant coliform (TTC) household water contamination in Kericho District, Western Kenya. Culture and multiplex polymerase chain reaction (PCR) techniques were used to characterize TTCs. The disk diffusion method was used for antibiotic susceptibility profiling of pathogenic Escherichia coli. Out of the 103 households surveyed, 48 (46.6%) had TTC contaminated drinking water (TTC levels of >10 cfu/100 mL). Five of these households were contaminated with pathogenic E. coli, including 40% enteroaggregative E. coli, 40% enterotoxigenic E. coli, and 20% enteropathogenic E. coli. All these pathogenic E. coli strains were multidrug resistant to sulfamethoxazole/trimethoprim, ampicillin, tetracycline and ampicillin/sulbactam. Rural household locality, drinking water hand contact, water storage container cleaning practice, hand washing before water withdrawal, water source total coliforms <10 cfu/100 mL, temperature, and free chlorine levels were associated with TTC contamination of household drinking water. Significant proportions of household drinking water in Kericho District are contaminated with TTCs including with pathogenic multidrug-resistant E. coli. Source and household hygiene and practices contribute significantly to drinking water contamination.

Measuring organic carbon, nutrients and heavy metals in rivers receiving leachate from controlled and uncontrolled municipal solid waste (MSW) landfills

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

Yusof, N.; Department of Biology, Faculty of Science and Technology, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak; Haraguchi, A.

2009-10-15

Since landfilling is the common method of waste disposal in Malaysia, river water is greatly exposed to the risk of contamination from leachate unless proper leachate management is carried out. In this study, leachates from three different types of landfills, namely active uncontrolled, active controlled and closed controlled, were characterized, and their relationships with river water chemistry were examined monthly for a year. The influence of leachate on river water chemistry from each type of landfill depended on many factors, including the presence of a leachate control mechanism, leachate characteristics, precipitation, surface runoff and the applied treatment. The impact ofmore » leachate from an active uncontrolled landfill was the highest, as the organic content, NH{sub 4}{sup +}-N, Cd and Mn levels appeared high in the river. At the same time, influences of leachate were also observed from both types of controlled landfills in the form of inorganic nitrogen (NH{sub 4}{sup +}-N, NO{sub 3}{sup -}-N and NO{sub 2}{sup -}-N) and heavy metals (Fe, Cr, Ni and Mn). Improper treatment practice led to high levels of some contaminants in the stream near the closed controlled landfill. Meanwhile, the active controlled landfill, which was located near the coastline, was exposed to the risk of contamination resulting from the pyrite oxidation of the surrounding area.« less

Risk factors associated with Salmonella and Listeria monocytogenes contamination of produce fields.

PubMed

Strawn, Laura K; Gröhn, Yrjo T; Warchocki, Steven; Worobo, Randy W; Bihn, Elizabeth A; Wiedmann, Martin

2013-12-01

Identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective Good Agricultural Practices (GAPs). A cross-sectional study was conducted to (i) determine management practices associated with a Salmonella- or Listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. Over 5 weeks, 21 produce farms in New York State were visited. Field-level management practices were recorded for 263 fields, and 600 environmental samples (soil, drag swab, and water) were collected and analyzed for Salmonella and L. monocytogenes. Management practices were evaluated for their association with the presence of a pathogen-positive field. Salmonella and L. monocytogenes were detected in 6.1% and 17.5% of fields (n = 263) and 11% and 30% of water samples (n = 74), respectively. The majority of pathogen-positive water samples were from nonirrigation surface water sources. Multivariate analysis showed that manure application within a year increased the odds of a Salmonella-positive field (odds ratio [OR], 16.7), while the presence of a buffer zone had a protective effect (OR, 0.1). Irrigation (within 3 days of sample collection) (OR, 6.0), reported wildlife observation (within 3 days of sample collection) (OR, 6.1), and soil cultivation (within 7 days of sample collection) (OR, 2.9) all increased the likelihood of an L. monocytogenes-positive field. Our findings provide new data that will assist growers with science-based evaluation of their current GAPs and implementation of preventive controls that reduce the risk of preharvest contamination.

Risk Factors Associated with Salmonella and Listeria monocytogenes Contamination of Produce Fields

PubMed Central

Gröhn, Yrjo T.; Warchocki, Steven; Worobo, Randy W.; Bihn, Elizabeth A.; Wiedmann, Martin

2013-01-01

Identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective Good Agricultural Practices (GAPs). A cross-sectional study was conducted to (i) determine management practices associated with a Salmonella- or Listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. Over 5 weeks, 21 produce farms in New York State were visited. Field-level management practices were recorded for 263 fields, and 600 environmental samples (soil, drag swab, and water) were collected and analyzed for Salmonella and L. monocytogenes. Management practices were evaluated for their association with the presence of a pathogen-positive field. Salmonella and L. monocytogenes were detected in 6.1% and 17.5% of fields (n = 263) and 11% and 30% of water samples (n = 74), respectively. The majority of pathogen-positive water samples were from nonirrigation surface water sources. Multivariate analysis showed that manure application within a year increased the odds of a Salmonella-positive field (odds ratio [OR], 16.7), while the presence of a buffer zone had a protective effect (OR, 0.1). Irrigation (within 3 days of sample collection) (OR, 6.0), reported wildlife observation (within 3 days of sample collection) (OR, 6.1), and soil cultivation (within 7 days of sample collection) (OR, 2.9) all increased the likelihood of an L. monocytogenes-positive field. Our findings provide new data that will assist growers with science-based evaluation of their current GAPs and implementation of preventive controls that reduce the risk of preharvest contamination. PMID:24077713

Survival of Cryptosporidium parvum oocysts in calf housing facilities in the New York City watersheds.

PubMed

Collick, A S; Fogarty, E A; Ziegler, P E; Walter, M T; Bowman, D D; Steenhuis, T S

2006-01-01

Pathogen contamination of the public drinking water supply in the New York City watersheds is a serious concern. New York City's Watershed Agriculture Program is working with dairy farms in the watersheds to implement management practices that will reduce the risk of pathogens contaminating the water supply. Solar calf housing (SCH) was suggested as a best management practice (BMP) to control Cryptosporidium parvum, a common protozoan parasite that causes disease in humans. This BMP targets young calves because they are the primary source of C. parvum in dairy herds. The objective of this project was to assess and compare the survivability of C. parvum in SCH and in conventional calf housing (CCH), usually located in the main barn. C. parvum oocysts were secured in sentinel chambers and placed in SCH and CCH bedding on four farms. The chambers were in thermal, chemical, and moisture equilibrium with their microenvironments. An oocyst-filled control chamber, sealed from its surroundings, was placed near each chamber. Chambers and controls were sampled after 4, 6, and 8 wk. Oocyst viability in the chambers decreased to less than 10% in warm months and between 15 and 30% in the winter months. The viability of the control oocysts was similar to the chambers during warm months and generally higher during winter months. There was no significant (P > 0.05) difference in the viability decrease between SCH and CCH. Although oocyst viability was similar in both types of calf housing, SCH allow contaminated calf manure to be isolated from the main barn manure and potentially managed differently and in a way to decrease the number of viable oocysts entering the environment during field spreading.

Solid amine development program

NASA Technical Reports Server (NTRS)

Lovell, J. S.

1973-01-01

A regenerable solid amine material to perform the functions of humidity control and CO2 removal for space shuttle type vehicle is reported. Both small scale and large scale testing have shown this material to be competitive, especially for the longer shuttle missions. However, it had been observed that the material off-gasses ammonia under certain conditions. This presents two concerns. The first, that the ammonia would contaminate the cabin atmosphere, and second, that the material is degrading with time. An extensive test program has shown HS-C to produce only trace quantities of atmospheric contaminants, and under normal extremes, to have no practical life limitation.

Hospital Clostridium difficile outbreak linked to laundry machine malfunction.

PubMed

Sooklal, Shelini; Khan, Ayesha; Kannangara, Saman

2014-06-01

Clostridium difficile is a gram-positive, spore-forming anaerobic bacillus that is associated with diarrheal disease. C difficile is shed in the feces of affected individuals and its spores can survive on surfaces for prolonged periods of time. These spores can contaminate a hospital environment by spread through health care workers and suboptimal environmental cleaning practices. We report an outbreak of health care facility-onset C difficile infection that was eventually linked to contaminated mop pads after a laundry machine malfunction. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Helminth infections in domestic dogs from Russia

PubMed Central

Moskvina, T. V.; Ermolenko, A. V.

2016-01-01

Dogs are the hosts for a wide helminth spectrum including tapeworms, flatworms, and nematodes. These parasites affect the dog health and cause morbidity and mortality, especially in young and old animals. Some species, as Toxocara canis, Ancylostoma caninum, Dipylidium caninum, and Echinococcus spp. are well-known zoonotic parasites worldwide, resulting in high public health risks. Poor data about canine helminth species and prevalence are available in Russia, mainly due to the absence of official guidelines for the control of dog parasites. Moreover, the consequent low quality of veterinary monitoring and use of preventive measures, the high rate of environmental contamination by dog feces and the increase of stray dog populations, make the control of the environmental contamination by dog helminths very difficult in this country. This paper reviews the knowledge on canine helminth fauna and prevalence in Russia. Practical aspects related to diagnosis, treatment, and control of parasitic diseases of dogs in Russia are discussed. PMID:27956777

Proposed modification to avoidance test with Eisenia fetida to assess metal toxicity in agricultural soils affected by mining activities.

PubMed

Delgadillo, Víctor; Verdejo, José; Mondaca, Pedro; Verdugo, Gabriela; Gaete, Hernán; Hodson, Mark E; Neaman, Alexander

2017-06-01

Use of avoidance tests is a quick and cost-effective method of assessing contaminants in soils. One option for assessing earthworm avoidance behavior is a two-section test, which consists of earthworms being given the choice to move between a test soil and a control substrate. For ecological relevance, tested soils should be field-contaminated soils. For practical reasons, artificial soils are commonly used as the control substrate. Interpretation of the test results compromised when the test soil and the artificial substrate differ in their physico-chemical properties other than just contaminants. In this study we identified the physico-chemical properties that influence avoidance response and evaluated the usefulness of adjusting these in the control substrate in order to isolate metal-driven avoidance of field soils by earthworms. A standardized two-section avoidance test with Eisenia fetida was performed on 52 uncontaminated and contaminated (Cu >155mgkg -1 , As >19mgkg -1 ) agricultural soils from the Aconcagua River basin and the Puchuncaví Valley in Chile. Regression analysis indicated that the avoidance response was determined by soil organic matter (OM), electrical conductivity (EC) and total soil Cu. Organic matter content of the artificial substrate was altered by peat additions and EC by NaCl so that these properties matched those of the field soils. The resultant EC 80 for avoidance (indicative of soils of "limited habitat") was 433mg Cu kg -1 (339 - 528mgkg -1 95% confidence intervals). The earthworm avoidance test can be used to assess metal toxicity in field-contaminated soils by adjusting physico-chemical properties (OM and EC) of the artificial control substrate in order to mimic those of the field-collected soil. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Temperature and Nutrient Concentration on Survival of Foodborne Pathogens in Deciduous Fruit Processing Environments for Effective Hygiene Management.

PubMed

Duvenage, Stacey; Korsten, Lise

2016-11-01

Temperature and good sanitation practices are important factors for controlling growth of microorganisms. Fresh produce is stored at various temperatures to ensure quality and to prolong shelf life. When foodborne pathogens survive and grow on fresh produce at storage temperatures, then additional control strategies are needed to inactivate these pathogens. The aim of this study was to determine how temperatures associated with deciduous fruit processing and storage facilities (0.5, 4, and 21°C) affect the growth and/or survival of Escherichia coli O157:H7, Listeria monocytogenes , Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus under different nutrient conditions (nutrient rich and nutrient poor) and on simulated contact surfaces (vinyl coupons). Information on the growth and survival of foodborne pathogens at specific deciduous fruit processing and storage temperatures (0.5°C) is not available. All pathogens except E. coli O157:H7 were able to survive on vinyl coupons at all temperatures. L. monocytogenes proliferated under both nutrient conditions independent of temperature. S. aureus was the pathogen least affected by nutrient conditions. The survival of foodborne pathogens on the vinyl coupons, a model system for studying surfaces in fruit preparation and storage environments, indicates the potential for cross-contamination of deciduous fruit products under poor sanitation conditions. Foodborne pathogens that can proliferate and survive at various temperatures under different nutrient conditions could lead to fruit cross-contamination. Temperature mismanagement, which could allow pathogen proliferation in contaminated fruit packing houses and storage environments, is a concern. Therefore, proper hygiene and sanitation practices, removal of possible contaminants, and proper food safety management systems are needed to ensure food safety.

An evaluation of varying protocols for high-level disinfection of flexible fiberoptic laryngoscopes.

PubMed

Liming, Bryan; Funnell, Ian; Jones, Anthony; Demons, Samandra; Marshall, Kathryn; Harsha, Wayne

2014-11-01

The use of flexible fiberoptic laryngoscopes (FFLs) is ubiquitous in otolaryngology practices. As with any medical device, there exists a small risk for transmission of pathogenic microorganisms between patients, necessitating high-level decontamination between uses. Most of the literature to date has studied channeled scopes such as those used in esophagogastroduodenoscopy and colonoscopy. A recent study of nonchanneled flexible laryngoscopes suggested that current high-level decontamination practices in use at some institutions, including ours, may be overly aggressive. We sought to evaluate and compare the efficacy of varying techniques of high-level disinfection of FFLs. FFLs were used in routine clinical encounters and then disinfected with a variety of techniques. The FFLs were then cultured for bacteria and fungi, and the rates of positive cultures were compared between the techniques and the controls. In this study, we took FFLs following use in routine clinical practice and disinfected them using one of eight decontamination protocols. We compared the bacterial and fungal culture results to positive and negative controls. We demonstrated that each of the eight cleaning protocols was statistically efficacious at removing bacterial contamination. Our results for fungal cultures did not reach statistical significance. Using in vitro inoculation of FFLs, this study demonstrated that quicker and more cost-effective practices are equally efficacious to more time-consuming and expensive techniques with regard to bacterial contamination of FFLs. NA © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Evaluation of hygiene practices and microbiological status of ready-to-eat vegetable salads in Spanish school canteens.

PubMed

Rodríguez-Caturla, Magdevis Y; Valero, Antonio; Carrasco, Elena; Posada, Guiomar D; García-Gimeno, Rosa M; Zurera, Gonzalo

2012-08-30

This study was conducted in eight Spanish school canteens during the period 2008-2009. Food handlers' practices, kitchen equipment, hygiene/sanitation conditions and handling practices were evaluated using checklists. In parallel, the microbiological quality and safety of ready-to-eat (RTE) vegetable salads were assessed. In addition, food contact surfaces and environmental air quality of different areas were analysed. The study determined the relationship between the microbiological quality of RTE foods and food handling practices, together with the degree of contamination of working surfaces and environmental contamination of processing and distribution areas. Some deficiencies were found regarding the use and change of gloves, hand-washing and cleanliness of working surfaces. The microbial levels detected in the foods examined indicated the absence of pathogens in the samples analysed. Surface counts were higher on cutting boards and faucets, showing insufficient cleanliness procedures. This study constitutes a descriptive analysis of the hygiene/sanitation conditions implemented in food service systems in eight Spanish school canteens. The results should help risk managers to better define control measures to be adopted in order to prevent foodborne infections. Copyright © 2012 Society of Chemical Industry.

Diversity and Control of Spoilage Fungi in Dairy Products: An Update

PubMed Central

Valence, Florence; Mounier, Jérôme

2017-01-01

Fungi are common contaminants of dairy products, which provide a favorable niche for their growth. They are responsible for visible or non-visible defects, such as off-odor and -flavor, and lead to significant food waste and losses as well as important economic losses. Control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit fungal spoilage in dairy products. Several traditional methods also called traditional hurdle technologies are implemented and combined to prevent and control such contaminations. Prevention methods include good manufacturing and hygiene practices, air filtration, and decontamination systems, while control methods include inactivation treatments, temperature control, and modified atmosphere packaging. However, despite technology advances in existing preservation methods, fungal spoilage is still an issue for dairy manufacturers and in recent years, new (bio) preservation technologies are being developed such as the use of bioprotective cultures. This review summarizes our current knowledge on the diversity of spoilage fungi in dairy products and the traditional and (potentially) new hurdle technologies to control their occurrence in dairy foods. PMID:28788096

Frequency of inadequate chicken cross-contamination prevention and cooking practices in restaurants.

PubMed

Green Brown, Laura; Khargonekar, Shivangi; Bushnell, Lisa

2013-12-01

This study was conducted by the Environmental Health Specialists Network (EHS-Net) of the Centers for Disease Control and Prevention. The purpose was to examine restaurant chicken preparation and cooking practices and kitchen managers' food safety knowledge concerning chicken. EHS-Net members interviewed managers about chicken preparation practices in 448 restaurants. The study revealed that many restaurants were not following U.S. Food and Drug Administration Food Code guidance concerning cross-contamination prevention and proper cooking and that managers lacked basic food safety knowledge about chicken. Forty percent of managers said that they never, rarely, or only sometimes designated certain cutting boards for raw meat (including chicken). One-third of managers said that they did not wash and rinse surfaces before sanitizing them. Over half of managers said that thermometers were not used to determine the final cook temperature of chicken. Only 43% of managers knew the temperature to which raw chicken needed to be cooked for it to be safe to eat. These findings indicate that restaurant chicken preparation and cooking practices and manager food safety knowledge need improvement. Findings from this study could be used by food safety programs and the restaurant industry to target training and intervention efforts to improve chicken preparation and cooking practices and knowledge concerning safe chicken preparation.

Frequency of Inadequate Chicken Cross-Contamination Prevention and Cooking Practices in Restaurants

PubMed Central

Brown, Laura Green; Khargonekar, Shivangi; Bushnell, Lisa

2017-01-01

This study was conducted by the Environmental Health Specialists Network (EHS-Net) of the Centers for Disease Control and Prevention. The purpose was to examine restaurant chicken preparation and cooking practices and kitchen managers’ food safety knowledge concerning chicken. EHS-Net members interviewed managers about chicken preparation practices in 448 restaurants. The study revealed that many restaurants were not following U.S. Food and Drug Administration Food Code guidance concerning cross-contamination prevention and proper cooking and that managers lacked basic food safety knowledge about chicken. Forty percent of managers said that they never, rarely, or only sometimes designated certain cutting boards for raw meat (including chicken). One-third of managers said that they did not wash and rinse surfaces before sanitizing them. Over half of managers said that thermometers were not used to determine the final cook temperature of chicken. Only 43% of managers knew the temperature to which raw chicken needed to be cooked for it to be safe to eat. These findings indicate that restaurant chicken preparation and cooking practices and manager food safety knowledge need improvement. Findings from this study could be used by food safety programs and the restaurant industry to target training and intervention efforts to improve chicken preparation and cooking practices and knowledge concerning safe chicken preparation. PMID:24290693

Safe injection practices for administration of propofol.

PubMed

King, Cecil A; Ogg, Mary

2012-03-01

Sepsis and postoperative infection can occur as a result of unsafe practices in the administration of propofol and other injectable medications. Investigations of infection outbreaks have revealed the causes to be related to bacterial growth in or contamination of propofol and unsafe medication practices, including reuse of syringes on multiple patients, use of single-use medication vials for multiple patients, and failure to practice aseptic technique and adhere to infection control practices. Surveys conducted by AORN and other researchers have provided additional information on perioperative practices related to injectable medications. In 2009, the US Food and Drug Administration and the Centers for Disease Control and Prevention convened a group of clinicians to gain a better understanding of the issues related to infection outbreaks and injectable medications. The meeting participants proposed collecting data to persuade clinicians to adopt new practices, developing guiding principles for propofol use, and describing propofol-specific, site-specific, and practitioner-specific injection techniques. AORN provides resources to help perioperative nurses reduce the incidence of postoperative infection related to medication administration. Copyright © 2012 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Electrokinetic-enhanced bioaugmentation for remediation of chlorinated solvents contaminated clay

PubMed Central

Mao, Xuhui; Wang, James; Ciblak, Ali; Cox, Evan E.; Riis, Charlotte; Terkelsen, Mads; Gent, David B.; Alshawabkeh, Akram N.

2012-01-01

Successful bioremediation of contaminated soils is controlled by the ability to deliver bioremediation additives, such as bacteria and/or nutrients, to the contaminated zone. Because hydraulic advection is not practical for delivery in clays, electrokinetic (EK) injection is an alternative for efficient and uniform delivery of bioremediation additive into low-permeability soil and heterogeneous deposits. EK–enhanced bioaugmentation for remediation of clays contaminated with chlorinated solvents is evaluated. Dehalococcoides (Dhc) bacterial strain and lactate ions are uniformly injected in contaminated clay and complete dechlorination of chlorinated ethene is observed in laboratory experiments. The injected bacteria can survive, grow, and promote effective dechlorination under EK conditions and after EK application. The distribution of Dhc within the clay suggests that electrokinetic transport of Dhc is primarily driven by electroosmosis. In addition to biodegradation due to bioaugmentation of Dhc, an EK-driven transport of chlorinated ethenes is observed in the clay, which accelerates cleanup of chlorinated ethenes from the anode side. Compared with conventional advection-based delivery, EK injection is significantly more effective forestablis hingmicrobial reductive dechlorination capacity in low-permeability soils. PMID:22365139

Contamination control plan for prelaunch operations

NASA Technical Reports Server (NTRS)

Austin, J. D.

1983-01-01

A unified, systematic plan is presented for contamination control for space flight systems. Allowable contaminant quantities, or contamination budgets, are determined based on system performance margins and system-level allowable degradations. These contamination budgets are compared to contamination rates in ground environments to establish the controls required in each ground environment. The use of feedback from contamination monitoring and some contamination control procedures are discussed.

Implementation of 10 CFR 20.1406 Through Life Cycle Planning for Decommissioning

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

O'Donnell, E.; Ott, W.R.

2008-01-15

The focus of this paper is on a regulatory guide (draft guide DG-4012) being developed by the Office of Nuclear Regulatory Research for the implementation of 10 CFR 20.1406. The draft guide was published in the Federal Register on July 31, 2007 for a 90 day public comment period. Besides being available in the Federal Register, it is also available electronically in NRC's agency data management system (ADAMS). The accession number is ML0712100110. 10 CFR 20.1406 requires license applicants, other than renewals, after August 20, 1997, '..to describe in the application how facility design and procedures for operation will minimize,more » to the extent practicable, contamination of the facility and the environment, facilitate eventual decommissioning, and minimize to the extent practicable, the generation of radioactive waste'. The intent of the regulation is to diminish the occurrence and severity of 'legacy sites' by taking measures that will reduce and control contamination and facilitate eventual decommissioning. 10 CFR 20.1406 is significant because it applies to all new facilities and in the very near future (perhaps as soon as the fall of 2007), the U.S. Nuclear Regulatory Commission (NRC) anticipates receiving one or more license applications for new nuclear power plants. The regulatory guide is intended to facilitate that licensing by providing suggestions of things an applicant can do to minimize contamination of the facility and the environment, minimize generation of waste, and to facilitate decommissioning. Over 100 different kinds of activities are covered by license applications submitted to the NRC. They do not all reflect the same potential for contamination of a facility and the environment, or for the generation of radioactive waste. Therefore, an applicant should use sound judgment to evaluate the potential for contamination and the consequences of such contamination in deciding on the extent to which this guide applies to any given facility or activity. Factors which may enter into this decision include form (e.g., dry solids, liquids, gases), inventory, and environmental mobility of unintended releases. The bulk of the guidance presented in the guide will consist of specific design considerations drawn from nuclear industry experience and lessons learned from decommissioning. These design suggestions provide examples of measures which can be combined to support a contaminant management philosophy for a new facility. The principles embodied in this philosophy are threefold: (1) prevention of unintended release, (2) early detection if there is unintended release of radioactive contamination, and (3) prompt and aggressive clean-up should there be an unintended release of radioactive contamination. If the guiding principles are followed through the use of 'good' engineering and science, as well as careful attention to operational practices, it should result in meeting the requirements of 10 CFR 20.1406. All this should be considered in the context of the life cycle of the facility from the early planning stages through the final plans for decommissioning and waste disposal. Some of the mechanisms which can be employed for life cycle planning are described further in the Discussion section. In summary: The principles of the guide are threefold: prevention, early detection, and prompt response. If these guiding principles are followed through the use of 'good' engineering and science, as well as careful attention to operational practices, it should result in meeting the requirements of 10 CFR 20 In summary, the thrust of this guide is for an applicant to use technically sound engineering judgment and a practical risk-informed approach to achieve the objectives of 10 CFR 20.1406. This approach should consider the materials and processes involved (e.g., solids, liquids, gases) and focus on: (1) the relative significance of potential contamination; (2) areas most susceptible to leaks; and (3) the appropriate level of consideration to prevention and control of contamination that should be incorporated in facility design. Since the applicability of the guidance is a facility-by-facility decision, early consultation with the NRC is strongly suggested.« less

Biotechnological advances for combating Aspergillus flavus and aflatoxin contamination in crops.

PubMed

Bhatnagar-Mathur, Pooja; Sunkara, Sowmini; Bhatnagar-Panwar, Madhurima; Waliyar, Farid; Sharma, Kiran Kumar

2015-05-01

Aflatoxins are toxic, carcinogenic, mutagenic, teratogenic and immunosuppressive byproducts of Aspergillus spp. that contaminate a wide range of crops such as maize, peanut, and cotton. Aflatoxin not only affects crop production but renders the produce unfit for consumption and harmful to human and livestock health, with stringent threshold limits of acceptability. In many crops, breeding for resistance is not a reliable option because of the limited availability of genotypes with durable resistance to Aspergillus. Understanding the fungal/crop/environment interactions involved in aflatoxin contamination is therefore essential in designing measures for its prevention and control. For a sustainable solution to aflatoxin contamination, research must be focused on identifying and improving knowledge of host-plant resistance factors to aflatoxin accumulation. Current advances in genetic transformation, proteomics, RNAi technology, and marker-assisted selection offer great potential in minimizing pre-harvest aflatoxin contamination in cultivated crop species. Moreover, developing effective phenotyping strategies for transgenic as well as precision breeding of resistance genes into commercial varieties is critical. While appropriate storage practices can generally minimize post-harvest aflatoxin contamination in crops, the use of biotechnology to interrupt the probability of pre-harvest infection and contamination has the potential to provide sustainable solution. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Space Stirling Cryocooler Contamination Lessons Learned and Recommended Control Procedures

NASA Astrophysics Data System (ADS)

Glaister, D. S.; Price, K.; Gully, W.; Castles, S.; Reilly, J.

The most important characteristic of a space cryocooler is its reliability over a lifetime typically in excess of 7 years. While design improvements have reduced the probability of mechanical failure, the risk of internal contamination is still significant and has not been addressed in a consistent approach across the industry. A significant fraction of the endurance test and flight units have experienced some performance degradation related to internal contamination. The purpose of this paper is to describe and assess the contamination issues inside long life, space cryocoolers and to recommend procedures to minimize the probability of encountering contamination related failures and degradation. The paper covers the sources of contamination, the degradation and failure mechanisms, the theoretical and observed cryocooler sensitivity, and the recommended prevention procedures and their impact. We begin with a discussion of the contamination sources, both artificial and intrinsic. Next, the degradation and failure mechanisms are discussed in an attempt to arrive at a contaminant susceptibility, from which we can derive a contamination budget for the machine. This theoretical sensitivity is then compared with the observed sensitivity to illustrate the conservative nature of the assumed scenarios. A number of lessons learned on Raytheon, Ball, Air Force Research Laboratory, and NASA GSFC programs are shared to convey the practical aspects of the contamination problem. Then, the materials and processes required to meet the proposed budget are outlined. An attempt is made to present a survey of processes across industry.

Environmental cleaning and disinfection.

PubMed

Traverse, Michelle; Aceto, Helen

2015-03-01

The guidelines in this article provide veterinarians, veterinary technicians, and veterinary health care workers with an overview of evidence-based recommendations for the best practices associated with environmental cleaning and disinfection of a veterinary clinic that deals with small animals. Hospital-associated infections and the control and prevention programs necessary to alleviate them are addressed from an environmental perspective. Measures of hospital cleaning and disinfection include understanding mechanisms and types of contamination in veterinary settings, recognizing areas of potential concern, addressing appropriate decontamination techniques and selection of disinfectants, the management of potentially contaminated equipment, laundry, and waste management, and environmental surveillance strategies. Copyright © 2015 Elsevier Inc. All rights reserved.

Mapping microbial ecosystems and spoilage-gene flow in breweries highlights patterns of contamination and resistance

PubMed Central

Bokulich, Nicholas A; Bergsveinson, Jordyn; Ziola, Barry; Mills, David A

2015-01-01

Distinct microbial ecosystems have evolved to meet the challenges of indoor environments, shaping the microbial communities that interact most with modern human activities. Microbial transmission in food-processing facilities has an enormous impact on the qualities and healthfulness of foods, beneficially or detrimentally interacting with food products. To explore modes of microbial transmission and spoilage-gene frequency in a commercial food-production scenario, we profiled hop-resistance gene frequencies and bacterial and fungal communities in a brewery. We employed a Bayesian approach for predicting routes of contamination, revealing critical control points for microbial management. Physically mapping microbial populations over time illustrates patterns of dispersal and identifies potential contaminant reservoirs within this environment. Habitual exposure to beer is associated with increased abundance of spoilage genes, predicting greater contamination risk. Elucidating the genetic landscapes of indoor environments poses important practical implications for food-production systems and these concepts are translatable to other built environments. DOI: http://dx.doi.org/10.7554/eLife.04634.001 PMID:25756611

Source water assessment and nonpoint sources of acutely toxic contaminants: A review of research related to survival and transport of Cryptosporidium parvum

NASA Astrophysics Data System (ADS)

Walker, Mark J.; Montemagno, Carlo D.; Jenkins, Michael B.

1998-12-01

Amendments to the Safe Drinking Water Act (PL-930123) in 1996 required that public water supply managers identify potential sources of contamination within contributing areas. Nonpoint sources of acutely toxic microbial contaminants, such as Cryptosporidium parvum, challenge current approaches to source identification and management as a first step toward developing management plans for public water supply protection. Little may be known about survival and transport in the field environment, prescribed practices may not be designed to manage such substances, and infective stages may be present in vast numbers and may resist water treatment and disinfection processes. This review summarizes research related to survival and transport of C. parvum oocysts, as an example of an acutely toxic contaminant with nonpoint sources in animal agriculture. It discusses ∥1) significance of infected domesticated animals as potential sources of C. parvum, (2) laboratory and field studies of survival and transport, and (3) approaches to source control in the context of public health protection.

Behavioral Observation and Microbiological Analysis of Older Adult Consumers' Cross-Contamination Practices in a Model Domestic Kitchen.

PubMed

Evans, Ellen W; Redmond, Elizabeth C

2018-04-01

The incidence of foodborne illness is higher in older adults because of their increased susceptibility; therefore, food safety practices are important. However, inadequate knowledge and negative attitudes toward food safety have been reported, which may increase use of unsafe food handling practices. Data on the actual food safety behaviors of older adults are lacking. In this study, food safety practices of older adults were observed and linked to microbiological analysis of kitchen surfaces to identify suspected routes of contamination. Older adults (≥60 years, n = 100) prepared a set meal in a model domestic kitchen sanitized according to a validated protocol to ensure minimal and consistent microbiological loads. Food safety behaviors were observed using ceiling-mounted cameras and recorded using a predetermined behavioral checklist. Surface microbiological contamination also was determined after food preparation. Overall, older adults frequently implemented unsafe food handling practices; 90% failed to implement adequate hand decontamination immediately after handling raw chicken. For older adults who used a larger number of adequate hand decontamination attempts, microbiological contamination levels in the kitchen following the food preparation session were significantly lower ( P < 0.001). The novel utilization of behavioral observation in conjunction with microbiological analysis facilitated identification of potentially unsafe food handling practices as suspected routes of microbiological cross-contamination in a model domestic kitchen. Findings indicate the potential impact on domestic food safety of unsafe food handling practices used by older adult consumers. This innovative approach revealed that a large proportion of older adults implement behaviors resulting in microbiological cross-contamination that may increase the risk of foodborne illness in the home.

Automated control of linear constricted plasma source array

DOEpatents

Anders, Andre; Maschwitz, Peter A.

2000-01-01

An apparatus and method for controlling an array of constricted glow discharge chambers are disclosed. More particularly a linear array of constricted glow plasma sources whose polarity and geometry are set so that the contamination and energy of the ions discharged from the sources are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The quality of film along deposition "tracks" opposite the plasma sources can be measured and compared to desired absolute or relative values by optical and/or electrical sensors. Plasma quality can then be adjusted by adjusting the power current values, gas feed pressure/flow, gas mixtures or a combination of some or all of these to improve the match between the measured values and the desired values.

Survey of the contamination of eyedrops of hospital inpatients and recommendations for the changing of current practice in eyedrop dispensing.

PubMed Central

Stevens, J D; Matheson, M M

1992-01-01

Topical ophthalmic medications used on the ward and from the outpatient area have been taken and cultured for potential bacterial contamination in the laboratory. We examined 143 bottles used by patients who had had routine cataract surgery and trabeculectomy. We also examined for bacterial contamination 216 bottles of eyedrops used in the outpatient area of the hospital. No contamination was found in the postoperative eyedrops, but five bottles were contaminated from the outpatient area (2.3%). The bacterial growth from outpatient drops was of the same order of magnitude as in previous studies. The practice in the UK for postoperative eyedrops to be discarded and fresh, separate bottles to take home is discussed. We recommend that this practice be changed so that the postoperative drops used for 72 hours or less are taken home. PMID:1739689

A food contaminant detection system based on high-Tc SQUIDs

NASA Astrophysics Data System (ADS)

Tanaka, Saburo; Fujita, H.; Hatsukade, Y.; Nagaishi, T.; Nishi, K.; Ota, H.; Otani, T.; Suzuki, S.

2006-05-01

We have designed and constructed a computer controlled food contaminant detection system for practical use, based on high-Tc SQUID detectors. The system, which features waterproof stainless steel construction, is acceptable under the HACCP (Hazard Analysis and Critical Control Point) programme guidelines. The outer dimensions of the system are 1500 mm length × 477 mm width × 1445 mm height, and it can accept objects up to 200 mm wide × 80 mm high. An automatic liquid nitrogen filling system was installed in the standard model. This system employed a double-layered permeable metallic shield with a thickness of 1 mm as a magnetically shielded box. The distribution of the magnetic field in the box was simulated by FEM; the gap between each shield layer was optimized before fabrication. A shielding factor of 732 in the Z-component was achieved. This value is high enough to safely operate the system in a non-laboratory environment, i.e., a factory. During testing, we successfully detected a steel contaminant as small as 0.3 mm in diameter at a distance of 75 mm.

Microbial contamination of nonsterile pharmaceuticals in public hospital settings

PubMed Central

Mugoyela, Veronica; Mwambete, Kennedy D

2010-01-01

Purpose Contamination of pharmaceuticals with microorganisms irrespective whether they are harmful or nonpathogenic can bring about changes in physicochemical characteristics of the medicines. Although sterility is not a requirement in official compendia for nonsterile pharmaceuticals, bioburdens need to be within acceptable limits. Therefore, this study investigated microbial contamination of 10 nonsterile pharmaceuticals frequently delivered to outpatients by identifying and quantifying microbial contaminants and susceptibility pattern testing on the microbes isolated. Methods The study was carried out at Amana Municipal Hospital in Dar es Salaam, Tanzania. The protocol for the study involved structured selection of representative tablets, syrups, and capsules from the hospital’s outpatient pharmacy. Constitutive microorganisms were elaborated and enumerated using standard microbiologic procedures. Results Results showed that 50% of all tested products were heavily contaminated, and the predominant contaminants comprised Klebsiella, Bacillus, and Candida species. Furthermore, the results showed that the isolated Bacillus and Klebsiella species were resistant to Augmentin ® and cloxacillin. The differences in means for cfu/mL and zones of inhibition among the microorganisms isolated were considered significant at P < 0.05. Conclusion The nonsterile pharmaceuticals were presumably microbiologically contaminated due to poor handling during dispensing, repackaging, and/or nonadherence to good manufacturing practice. Therefore, training and educating the dispensers, as well as patients, on the proper handling and use of medicines cannot be overemphasized, because these are key aspects in controlling cross-contamination of medicines. PMID:20957135

Healthcare associated infection: good practices, knowledge and the locus of control in heatlhcare professionals.

PubMed

Taffurelli, Chiara; Sollami, Alfonso; Camera, Carmen; Federa, Francesca; Grandi, Annise; Marino, Marcella; Marrosu, Tiziano; Sarli, Leopoldo

2017-07-18

  The incidence of Healthcare Associated Infections (HAI) is an important indicator of the quality of care. The behaviors associated with the prevention of infections are not only supported by rational knowledge or motivation, but are mediated by social, emotional and often stereotyped behaviors. The awarness of the good practices related to HAI, may be a factor. Other studies, identify how the perception of the problem in healthcare professionals is often influenced by a tendency towards an external Locus of Control: the patient, the family, the other wards, other care settings. The aim of this study is to investigate the perception of healthcare professionals. In particular they have been measured their  awarness of the good practices, perceptions of the potential contamination level of some commonly used objects, knowledge about the management of invasive devices, Locus of Control.   A cross-sectional correlational design was utilized.  An ad hoc questionnaire was interviewed by 222 health professionals nurses and physicians in a northern hospital of Italy. The percentage of professionals who have attended training courses over the last 5 years was quite high, both for upgrades on HAI (78.7%) and Vascular Catheters (78.8%), while the percentage of professionals who updated on bladder catheterization (59.46%) was lower. The mean  score of good practice awareness towards HAI (5.06), is high. The perception of the potential level of contamination of some devices had a  mean ranging from 4.62 (for the drip) to 5.26 (for the door handle). The average value of the Locus of Control (43.54) indicates that participants demonstrated a value that is midway between External and Internal. The correlation test analysis revealed no significant relationships among professionals'age, knowledge about HAI, or infection related venus catheter. Also, results revealed that there were statistically significant positive relationships between professionals' Good Practices awareness about HAI , Knowledge, and Locus of Control. The study findings demonstrated that good practice awareness towards HAI among nurse and physician was good but not completely optimal. Findings revealed that knowledge toward HAI prevention and HAI related device prevention were not completely adequate. The educational courses, according to our correlational findings, should definitely take into account the psycho-social aspects of this phenomenon.

PAH contamination in Beijing’s topsoil: A unique indicator of the megacity’s evolving energy consumption and overall environmental quality

PubMed Central

Li, Jinguo; Zheng, Yi; Luo, Xiaolin; Lin, Zhongrong; Zhang, Wei; Wang, Xuejun

2016-01-01

To improve its air quality, Beijing, the capital of China, has implemented high-cost pollution control measures mainly focused on shifting its energy mix. However, the effectiveness of these measures has long been questioned, especially given the recent problem of severe haze. The main study objectives are to achieve independent, although indirect, information on Beijing’s air pollution by measuring the level of polycyclic aromatic hydrocarbon (PAH) contamination in topsoil and to examine how soil contamination reflects energy consumption. Soil sampling data from two years, 2004 and 2013, were used. The key findings are as follows: 1) although the total PAH content in the topsoil did not significantly decrease from 2004 to 2013, the composition changed considerably; 2) as of 2013, vehicle emissions replaced coal combustion as the leading source of soil PAHs, which validates the existing policy measures regarding vehicle purchasing and traffic volume; 3) the regional transport of atmospheric pollutants, as indicated by the contribution of coking sources in 2013, is not negligible; and 4) appropriate policy measures are needed to control the growing practice of burning biomass. Overall, this study demonstrates that the PAH contamination in topsoil represents an informative indicator of Beijing’s energy consumption and overall environmental quality. PMID:27633056

Using Coupled Energy, Airflow and IAQ Software (TRNSYS/CONTAM) to Evaluate Building Ventilation Strategies

PubMed Central

Dols, W. Stuart.; Emmerich, Steven J.; Polidoro, Brian J.

2016-01-01

Building energy analysis tools are available in many forms that provide the ability to address a broad spectrum of energy-related issues in various combinations. Often these tools operate in isolation from one another, making it difficult to evaluate the interactions between related phenomena and interacting systems, forcing oversimplified assumptions to be made about various phenomena that could otherwise be addressed directly with another tool. One example of such interdependence is the interaction between heat transfer, inter-zone airflow and indoor contaminant transport. In order to better address these interdependencies, the National Institute of Standards and Technology (NIST) has developed an updated version of the multi-zone airflow and contaminant transport modelling tool, CONTAM, along with a set of utilities to enable coupling of the full CONTAM model with the TRNSYS simulation tool in a more seamless manner and with additional capabilities that were previously not available. This paper provides an overview of these new capabilities and applies them to simulating a medium-size office building. These simulations address the interaction between whole-building energy, airflow and contaminant transport in evaluating various ventilation strategies including natural and demand-controlled ventilation. Practical Application CONTAM has been in practical use for many years allowing building designers, as well as IAQ and ventilation system analysts, to simulate the complex interactions between building physical layout and HVAC system configuration in determining building airflow and contaminant transport. It has been widely used to design and analyse smoke management systems and evaluate building performance in response to chemical, biological and radiological events. While CONTAM has been used to address design and performance of buildings implementing energy conserving ventilation systems, e.g., natural and hybrid, this new coupled simulation capability will enable users to apply the tool to couple CONTAM with existing energy analysis software to address the interaction between indoor air quality considerations and energy conservation measures in building design and analysis. This paper presents two practical case studies using the coupled modelling tool to evaluate IAQ performance of a CO2-based demand-controlled ventilation system under different levels of building envelope airtightness and the design and analysis of a natural ventilation system. PMID:27099405

Swabbing of waiting room magazines reveals only low levels of bacterial contamination

PubMed Central

Charnock, Colin

2005-01-01

Previous studies have shown that toys in waiting rooms of general practice surgeries can be contaminated with potentially pathogenic bacteria. The question was raised as to whether magazines might also be sources of contamination. Swabbing of the front page of 15 magazines from 11 general practice surgeries, followed by analysis for total and specific bacteria, revealed low levels of contamination. Among targeted groups of pathogens only two colonies of Staphylococcus aureus were detected. Magazines do not seem to be potentially important vectors of bacterial transfer in the setting examined. PMID:15667764

Mercury contaminated sediment sites-an evaluation of remedial options.

PubMed

Randall, Paul M; Chattopadhyay, Sandip

2013-08-01

Mercury (Hg) is a naturally-occurring element that is ubiquitous in the aquatic environment. Though efforts have been made in recent years to decrease Hg emissions, historically-emitted Hg can be retained in the sediments of aquatic bodies where they may be slowly converted to methylmercury (MeHg). Consequently, Hg in historically-contaminated sediments can result in high levels of significant exposure for aquatic species, wildlife and human populations consuming fish. Even if source control of contaminated wastewater is achievable, it may take a very long time, perhaps decades, for Hg-contaminated aquatic systems to reach relatively safe Hg levels in both water and surface sediment naturally. It may take even longer if Hg is present at higher concentration levels in deep sediment. Hg contaminated sediment results from previous releases or ongoing contributions from sources that are difficult to identify. Due to human activities or physical, chemical, or biological processes (e.g. hydrodynamic flows, bioturbation, molecular diffusion, and chemical transformation), the buried Hg can be remobilized into the overlying water. Hg speciation in the water column and sediments critically affect the reactivity (i.e. conversion of inorganic Hg(II) to MeHg), transport, and its exposure to living organisms. Also, geochemical conditions affect the activity of methylating bacteria and its availability for methylation. This review paper discusses remedial considerations (e.g. key chemical factors in fate and transport of Hg, source characterization and control, environmental management procedures, remediation options, modeling tools) and includes practical case studies for cleaning up Hg-contaminated sediment sites. Published by Elsevier Inc.

Bacteriophages and dairy fermentations

PubMed Central

Marcó, Mariángeles Briggiler; Moineau, Sylvain; Quiberoni, Andrea

2012-01-01

This review highlights the main strategies available to control phage infection during large-scale milk fermentation by lactic acid bacteria. The topics that are emphasized include the factors influencing bacterial activities, the sources of phage contamination, the methods available to detect and quantify phages, as well as practical solutions to limit phage dispersion through an adapted factory design, the control of air flow, the use of adequate sanitizers, the restricted used of recycled products, and the selection and growth of bacterial cultures. PMID:23275866

Operational practices associated with foodborne disease outbreaks in the catering industry in England and Wales.

PubMed

Jones, Sarah L; Parry, Sharon M; O'Brien, Sarah J; Palmer, Stephen R

2008-08-01

Catering businesses continue to be the most common setting for foodborne disease outbreaks. In a study of catering businesses in England and Wales, operational practices relating to the supply, preparation, and service of food in 88 businesses associated with outbreaks were compared with those practices at 88 control businesses. Operational practices did not differ significantly between case and control businesses but larger small medium-size enterprise (SME) businesses were more likely to be associated with foodborne disease outbreaks than were micro-SME businesses. Businesses associated with outbreaks of Salmonella infection were less likely to use local or national suppliers but instead used regional suppliers, especially for eggs. This practice was the only significantly independent operational practice associated with outbreaks of Salmonella infection. Regional egg suppliers also were more likely to be used by businesses associated with outbreaks attributed to food vehicles containing eggs. Businesses associated with egg-associated outbreaks were less likely to use eggs produced under an approved quality assurance scheme, suggesting that the underlying risk associated with using regional suppliers may relate to the use of contaminated eggs.

Validation and Application of Models to Predict Facemask Influenza Contamination in Healthcare Settings

PubMed Central

Fisher, Edward M.; Noti, John D.; Lindsley, William G.; Blachere, Francoise M.; Shaffer, Ronald E.

2015-01-01

Facemasks are part of the hierarchy of interventions used to reduce the transmission of respiratory pathogens by providing a barrier. Two types of facemasks used by healthcare workers are N95 filtering facepiece respirators (FFRs) and surgical masks (SMs). These can become contaminated with respiratory pathogens during use, thus serving as potential sources for transmission. However, because of the lack of field studies, the hazard associated with pathogen-exposed facemasks is unknown. A mathematical model was used to calculate the potential influenza contamination of facemasks from aerosol sources in various exposure scenarios. The aerosol model was validated with data from previous laboratory studies using facemasks mounted on headforms in a simulated healthcare room. The model was then used to estimate facemask contamination levels in three scenarios generated with input parameters from the literature. A second model estimated facemask contamination from a cough. It was determined that contamination levels from a single cough (≈19 viruses) were much less than likely levels from aerosols (4,473 viruses on FFRs and 3,476 viruses on SMs). For aerosol contamination, a range of input values from the literature resulted in wide variation in estimated facemask contamination levels (13–202,549 viruses), depending on the values selected. Overall, these models and estimates for facemask contamination levels can be used to inform infection control practice and research related to the development of better facemasks, to characterize airborne contamination levels, and to assist in assessment of risk from reaerosolization and fomite transfer because of handling and reuse of contaminated facemasks. PMID:24593662

Engineered Hyporheic Zones as Novel Water Quality Best Management Practice: Flow and Contaminant Attenuation in Constructed Stream Experiments

NASA Astrophysics Data System (ADS)

Herzog, S.; McCray, J. E.; Higgins, C. P.

2015-12-01

The hyporheic zone is a hotspot for biogeochemical processing that can attenuate a variety of nonpoint source contaminants in streamwater. However, hyporheic zones in urban and agricultural streams are often degraded and poorly connected with surface water. In order to increase hyporheic exchange and improve water quality, we introduced engineered streambeds as a stormwater and restoration best management practice. Modifications to streambed hydraulic conductivity and reactivity are termed Biohydrochemical Enhancement structures for Streamwater Treatment (BEST). BEST are subsurface modules that utilize low- and high-permeability sediments to drive efficient hyporheic exchange, and reactive geomedia to increase reaction rates within the hyporheic zone. This work presents the first physical performance data of BEST modules at the pilot scale. BEST modules were installed in a constructed stream facility at the Colorado School of Mines in Golden, CO. This facility features two 15m artificial streams, which included an all sand control condition alongside the BEST test condition. Streams were continuously operated at a discharge of 1 L/s using recycled water. Time-lapse electrical resistivity surveys demonstrated that BEST modules provided substantially greater hyporheic exchange than the control condition. Water quality samples at the hyporheic and reach scales also revealed greater attenuation of nitrogen, coliforms, and select metals and trace organics by BEST modules relative to the control condition. These experimental results were also compared to previous numerical model simulations to evaluate model accuracy. Together, these results show that BEST may be an effective best management practice for improving streamwater quality in urban and agricultural settings.

Environmental and body contamination from cleaning vomitus in a health care setting: A simulation study.

PubMed

Phan, Linh; Su, Yu-Min; Weber, Rachel; Fritzen-Pedicini, Charissa; Edomwande, Osayuwamen; Jones, Rachael M

2018-04-01

Environmental service workers may be exposed to pathogens during the cleaning of pathogen-containing bodily fluids. Participants with experience cleaning hospital environments were asked to clean simulated, fluorescein-containing vomitus using normal practices in a simulated patient room. Fluorescein was visualized in the environment and on participants under black lights. Fluorescein was quantitatively measured on the floor, in the air, and on gloves and shoe covers. In all 21 trials involving 7 participants, fluorescein was found on the floor after cleaning and on participants' gloves. Lower levels of floor contamination were associated with the use of towels to remove bulk fluid (ρ = -0.56, P = .01). Glove contamination was not associated with the number or frequency of contacts with environmental surfaces, suggesting contamination occurs with specific events, such as picking up contaminated towels. Fluorescein contamination on shoe covers was measured in 19 trials. Fluorescein was not observed on participants' facial personal protective equipment, if worn, or faces. Contamination on other body parts, primarily the legs, was observed in 8 trials. Fluorescein was infrequently quantified in the air. Using towels to remove bulk fluid prior to mopping is part of the recommended cleaning protocol and should be used to minimize residual contamination. Contamination on shoes and the floor may serve as reservoirs for pathogens. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Bacterial contamination of re-usable laryngoscope blades during the course of daily anaesthetic practice.

PubMed

Lowman, Warren; Venter, Laurissa; Scribante, Juan

2013-02-19

Hospital-acquired infections (HAIs) are largely preventable through risk analysis and modification of practice. Anaesthetic practice plays a limited role in the prevention of HAIs, although laryngoscope use and decontamination is an area of concern. We aimed to assess the level of microbial contamination of re-usable laryngoscope blades at a public hospital in South Africa. The theatre complex of a secondary-level public hospital in Johannesburg. Blades from two different theatres were sampled twice daily, using a standardised technique, over a 2-week period. Samples were quantitatively assessed for microbial contamination, and stratified by area on blade, theatre and time using Fisher's exact test. A contamination rate of 57.3% (63/110) was found, with high-level contamination accounting for 22.2% of these. Common commensals were the most frequently isolated micro-organisms (79.1%), but important hospital pathogens such as Enterobacter species and Acinetobacter baumannii were isolated from blades with high-level contamination. No significant difference in the level of microbial contamination by area on blade, theatre or time was found (p<0.05). A combination of sub-optimal decontamination and improper handling of laryngoscopes after decontamination results in significant microbial contamination of re-usable laryngoscope blades. There is an urgent need to review protocols and policies surrounding the use of these blades.

Soil removal as a decontamination practice and radiocesium accumulation in tadpoles in rice paddies at Fukushima.

PubMed

Sakai, Masaru; Gomi, Takashi; Nunokawa, Masanori; Wakahara, Taeko; Onda, Yuichi

2014-04-01

We investigated the biological accumulation of radiocesium in tadpoles [Rana (Pelophylax) porosa porosa] in rice paddies with and without decontamination practice at Fukushima. Radiocesium was accumulated in surface part of soils both in the control and decontaminated paddies one year after decontamination. Mean (134)Cs and (137)Cs concentrations in tadpoles in the control and decontaminated paddies were 3000 and 4500, and 600 and 890 Bq/kg dry weight, respectively. Radiocesium concentrations in surface soil (0-5 cm depth) and tadpoles in the decontaminated paddy were five times smaller than in the control paddy. These results suggest that decontamination practice can reduce radiocesium concentrations in both soil and tadpoles. However, at the decontaminated paddy, radiocesium concentrations in surface soils became 3.8 times greater one year after decontamination, which indicates that monitoring the subsequent movement of radiocesium in rice paddies and surrounding areas is essential for examining contamination propagation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Space station contamination control study: Internal combustion, phase 1

NASA Technical Reports Server (NTRS)

Ruggeri, Robert T.

1987-01-01

Contamination inside Space Station modules was studied to determine the best methods of controlling contamination. The work was conducted in five tasks that identified existing contamination control requirements, analyzed contamination levels, developed outgassing specification for materials, wrote a contamination control plan, and evaluated current materials of offgassing tests used by NASA. It is concluded that current contamination control methods can be made to function on the Space Station for up to 1000 days, but that current methods are deficient for periods longer than about 1000 days.

An investigation into the bacterial contamination of goniolenses in use in clinical practice.

PubMed

Grundon, Rachael; Scurrell, Emma; Mould, John; Hayton-Lee, Emma; Heinrich, Christine

2017-12-18

Objectives To report the incidence and evaluate the clinical significance of goniolens bacterial contamination in clinical use in dogs with three different usage protocols and one with an added cleaning protocol. Animals Studied and Methods Three groups of twenty dogs undergoing gonioscopy at a private practice in the UK had the goniolenses swabbed for bacteriology culture and identification prior to placement on the cornea. Three protocols of lens use, with 2 different types of goniolens, were studied. One protocol was then repeated with 21 dogs with a lens cleaning protocol prior to storage. Results Low levels of bacterial contamination were found in all 3 initial groups (10-15%). No correlation was found between usage protocol used and rate of contamination and no correlation was found between length of storage between use and contamination. All bacteria cultured were considered naturally occurring commensals for the canine eye and environment. The group with a cleaning protocol had a 4.7% contamination rate. This was not statistically different from the non-cleaning groups. Conclusions The rate of bacterial contamination of goniolenses in clinical practice is low and the bacterial contaminants consist of commensal bacteria, unlikely to be of detriment to the eye. Minimal contamination of the goniolenses was found and this did not appear to be of clinical significance. The introduction of a simple cleaning protocol did not produce a statistically significant reduction in bacterial contamination. © 2017 American College of Veterinary Ophthalmologists.

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

Adams, S.R.

A comprehensive evaluation was conducted of the radiation protection practices and programs at prototype LMFBRs with long operational experience. Installations evaluated were the Fast Flux Test Facility (FFTF), Richland, Washington; Experimental Breeder Reactor II (EBR-II), Idaho Falls, Idaho; Prototype Fast Reactor (PFR) Dounreay, Scotland; Phenix, Marcoule, France; and Kompakte Natriumgekuhlte Kernreak Toranlange (KNK II), Karlsruhe, Federal Republic of Germany. The evaluation included external and internal exposure control, respiratory protection procedures, radiation surveillance practices, radioactive waste management, and engineering controls for confining radiation contamination. The theory, design, and operating experience at LMFBRs is described. Aspects of LMFBR health physics different frommore » the LWR experience in the United States are identified. Suggestions are made for modifications to the NRC Standard Review Plan based on the differences.« less

Contamination Control for Thermal Engineers

NASA Technical Reports Server (NTRS)

Rivera, Rachel B.

2015-01-01

The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard Spaceflight Center (GSFC) Thermal Engineering Branch (Code 545). This course will cover the basics of Contamination Control, including contamination control related failures, the effects of contamination on Flight Hardware, what contamination requirements translate to, design methodology, and implementing contamination control into Integration, Testing and Launch.

Prevention and control practices for human noroviruses in long-term care facilities in South Carolina.

PubMed

Leone, Cortney M; Jayasekara, Lalani; Sharp, Julia; Fraser, Angela

2015-12-01

Long-term care facilities (LTCFs) are the most common setting for human norovirus (HuNoV) outbreak. Our study aimed to determine gaps in prevention and control practices for HuNoV in LTCFs in South Carolina (SC). Two researchers visited a convenience sample of 26 LTCFs in SC during July-November 2013. Directors were interviewed to determine facility prevention and control practices. Relative frequencies and means were calculated using SAS 9.3 (SAS Institute, Cary, NC). Most directors had little knowledge of proper sanitizing and disinfecting products and reported missing written procedures for cleaning staff-visitor bathrooms. Only 18 had recommendations for when residents should wash hands. Many used the wrong products for pathogen removal after vomit-fecal events, had no written procedures for cleaning contaminated soft surfaces, did not remove other individuals during clean-up of vomit-fecal episodes, and did not clean a large area surrounding vomit-fecal episodes. Eighteen did not assign specific staff to care for sick; 16 did not designate specific toilets for sick; and 15 did not restrict visitors during an outbreak. Directors' responses indicated gaps in prevention and control practices for HuNoV in LTCFs in SC. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users.

PubMed

Thakur, Deeksha V; Gaikwad, Ujjwala N

2014-08-01

With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmic infections. Four samples each from 50 participants (n=200) were collected from the lenses, lens care solutions, lens care solution bottles and lens cases along with a questionnaire regarding their lens use. The samples were inoculated onto sheep blood agar, Mac Conkey's agar and Sabouraud's dextrose agar. Organisms were identified using standard laboratory protocols. Overall rate of microbial contamination among the total samples was 52 per cent. The most and the least contaminated samples were found to be lens cases (62%) and lens care solution (42%), respectively. The most frequently isolated contaminant was Staphylococcus aureus (21%) followed by Pseudomonas species (19.5%). Majority (64%) of the participants showed medium grade of compliance to lens cleaning practices. Rate of contamination was 100 and 93.75 per cent respectively in those participants who showed low and medium compliance to lens care practices as compared to those who had high level of compliance (43.75%) (P<0.05). Lens care practices amongst the participants were not optimum which resulted into high level contamination. Hence, creating awareness among the users about the lens care practices and regular cleaning and replacements of lens cases are required.

Space station trace contaminant control

NASA Technical Reports Server (NTRS)

Olcutt, T.

1985-01-01

Different systems for the control of space station trace contaminants are outlined. The issues discussed include: spacecabin contaminant sources, technology base, contaminant control system elements and configuration, approach to contaminant control, contaminant load model definition, spacecraft maximum allowable concentrations, charcoal bed sizing and performance characteristics, catalytic oxidizer sizing and performance characteristics, special sorbent bed sizing, animal and plant research payload problems, and emergency upset contaminant removal. It is concluded that the trace contaminant control technology base is firm, the necessary hardware tools are available, and the previous design philosophy is still applicable. Some concerns are the need as opposed to danger of the catalytic oxidizer, contaminants with very low allowable concentrations, and the impact of relaxing materials requirements.

Evaluation of the sources of contamination in the suburban area of Koropi-Markopoulo, Athens, Greece.

PubMed

Kaitantzian, Agavni; Kelepertzis, Efstratios; Kelepertsis, Akindynos

2013-07-01

Heavy metal concentrations were monitored in agricultural soils and irrigation groundwaters of Koropi-Markopoulo area, a representative agricultural suburb in Athens, Greece, aiming at the identification of the sources of contaminants. Multivariate analyses of geochemical data demonstrated that agricultural practices and industrial activities considerably affected the quality of both environmental compartments. The levels of Ni, Cr, Co, Mn and Fe in agricultural soils were associated with geological parent materials whereas Pb, Zn and Cu mainly originated from anthropic activities. Referring to groundwaters, individual major anions and cations (K⁺, Na⁺, Ca²⁺, Mg²⁺, NO₃⁻, SO₄²⁻, Cl⁻) were influenced by various natural and anthropogenic factors whereas Ni, Cr, Cu and Zn were controlled by industrial and agronomic activities. The identification of the sources of contaminants in soil and groundwater environments is a valuable basis for encouraging mitigation strategies preventing further quality degradation.

Watershed Characteristics and Land Management in the Nonpoint-Source Evaluation Monitoring Watersheds in Wisconsin

USGS Publications Warehouse

Rappold, K.F.; Wierl, J.A.; Amerson, F.U.

1997-01-01

In 1992, the Wisconsin Department of Natural Resources, in cooperation with the U.S. Geological Survey, began a land-use inventory to identify sources of contaminants and track the land-management changes for eight evaluation monitoring watersheds in Wisconsin. An important component of the land-use inventory has been developing descriptions and preliminary assessments for the eight watersheds. These descriptions establish a baseline for future data analysis. The watershed descriptions include sections on location, reference watersheds, climate, land use, soils and topography, and surface-water resources. The land-management descriptions include sections on objectives, sources of nonpoint contamination and goals of contaminant reduction, and implementation of best-management practices. This information was compiled primarily from the nonpoint-source control plans, county soil surveys, farm conservation plans, Federal and State agency data reports, and data collected through the land-use inventory.

30 CFR 57.5005 - Control of exposure to airborne contaminants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Underground § 57.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by prevention of contamination, removal by exhaust...

Reestablishing Public Health and Land Use Planning to Protect Public Water Supplies

PubMed Central

Greenberg, Michael; Mayer, Henry; Miller, K. Tyler; Hordon, Robert; Knee, Daniel

2003-01-01

Objectives. This study measured the extent to which land use, design, and engineering practices could reduce contamination of major public water supplies. Methods. Key parcels of land were identified in New Jersey, and the potential uncontrolled loading of contaminants was estimated with the US Environmental Protection Agency’s Long-Term Hydrologic Impact Assessment model for a variety of land use, design, and engineering scenarios. Results. High-density per-acre development and engineering controls, along with housing and light commercial activity near main railroads, would substantially reduce runoff. Conclusions. In New Jersey, government and purveyor action is being taken as a result of, and in support of, these findings. PMID:12948974

MSFC Skylab contamination control systems mission evaluation

NASA Technical Reports Server (NTRS)

1974-01-01

Cluster external contamination control evaluation was made throughout the Skylab Mission. This evaluation indicated that contamination control measures instigated during the design, development, and operational phases of this program were adequate to reduce the general contamination environment external to the Cluster below the threshold senstivity levels for experiments and affected subsystems. Launch and orbit contamination control features included eliminating certain vents, rerouting vents for minimum contamination impact, establishing filters, incorporating materials with minimum outgassing characteristics and developing operational constraints and mission rules to minimize contamination effects. Prior to the launch of Skylab, contamination control math models were developed which were used to predict Cluster surface deposition and background brightness levels throughout the mission. The report summarizes the Skylab system and experiment contamination control evaluation. The Cluster systems and experiments evaluated include Induced Atmosphere, Corollary and ATM Experiments, Thermal Control Surfaces, Solar Array Systems, Windows and Star Tracker.

41 CFR 109-42.1102-51 - Suspect personal property.

Code of Federal Regulations, 2010 CFR

2010-07-01

... radioactive or chemical contamination may occur shall be considered suspect and shall be monitored using... the level of contamination of excess or surplus personal property to the lowest practicable level. Contaminated personal property that exceeds applicable contamination standards shall not be utilized or...

Nurses' infection-control practice: hand decontamination, the use of gloves and sharp instruments.

PubMed

Gould, D; Wilson-Barnett, J; Ream, E

1996-04-01

Infection is an acknowledged hospital problem. Micro-organisms are disseminated mainly via hands but there is evidence that hand decontamination, the most important means of prevention, is performed too seldom, and not always after activities likely to result in heavy contamination. Nurses themselves are exposed to risks of infection, chiefly through contact with blood and body fluids, yet it has also been reported that gloves are not always worn during contact with patients' secretions and that the handling and disposal of sharp instruments may be performed unsafely. The study reported in this paper documents nursing behaviour in relation to hand decontamination, the use of gloves and sharps, taking into consideration a number of variables which could influence practice: availability of the expertise afforded by an infection-control nurse, clinical setting, nursing workload, knowledge and the resources available to control infection. Hands were decontaminated after 28.78% of patient contacts. Hands were decontaminated after 49.85% of activities likely to result in heavy contamination. Performance was related to nursing workload and the availability of hand decontaminating agents, especially when the nurses became busy. Use of gloves when they were available also proved good, with little evidence of wasteful use. The handling and disposal of sharps were commendable for most subjects but a few grossly unsafe incidents were nevertheless witnessed, apparently not associated with any of the variables examined.

Assessment of metal and PAH profiles in SUDS soil based on an improved experimental procedure.

PubMed

Tedoldi, Damien; Chebbo, Ghassan; Pierlot, Daniel; Kovacs, Yves; Gromaire, Marie-Christine

2017-11-01

The increasing use of infiltration-based systems for stormwater management questions the soil's ability to act as a long-term filter for runoff contaminants, and brings about operational matters regarding the most effective maintenance practices to enhance contaminant retention in SUDS. This paper reports the vertical extent of metal and PAH contamination in the soil of seven source-control devices in operation for more than 10 years, assessed via a two-step sampling strategy to optimize the representativeness of the contamination profiles. Metal distribution was typically characterized by a significant surface buildup, followed by a decrease in concentrations with increasing depth, usually coming close to the background values. PAH were more heterogeneously distributed with depth, but their accumulation was globally restricted to the upper 10-40 cm. This indicates an interesting potential for pollution interception by the upper horizons of soil, but does not necessarily prevent from downward fluxes, even while measuring low surface contents, as deeper strata may have lesser retention capacities. Specific amendments of the surface soil may help prevent this problem. Surface soil renewal - which would be necessary over 2.5-30 cm in four sites, according to the "strictest" standards for soil remediation - may regenerate the soil's sorption potential, but such a practice could disrupt the interactions with the local ecosystem, so this should be carried out exceptionally and not as a preventive measure. Copyright © 2017 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

Monitoring Salmonella, Campylobacter, Escherichia coli and Staphylococcus aureus in traditional free-range 'Label Rouge' broiler production: a 23-year survey programme.

PubMed

Salvat, G; Guyot, M; Protino, J

2017-01-01

'Label Rouge' broiler free-range carcasses have been monitored since 1991, and broiler flocks since 2010, for contamination by the main foodborne zoonotic bacteria. Initially, the monitoring plan mainly focused on the surveillance of Salmonella, and on indicators of the overall microbiological quality of free-range broiler carcasses such as Staphylococcus aureus and coliforms, but was extended in 2007 to include Campylobacter enumeration on carcasses and in 2010, to Salmonella in the environment of live birds. Salmonella contamination of free-range broiler carcasses rose to a peak of 16% in 1994 but less than 1% of carcasses are now regularly found to be positive. Indicators of the overall microbiological quality of carcasses are also improving. These results correlate with the low prevalence of Salmonella in free-range broiler breeding and production flocks, and with the continuous improvement of hazard analysis and critical control points in slaughterhouses, the implementation of a good manufacturing practice guide since 1997 and the application of EU regulations on Salmonella since 1998 in France. Regarding Campylobacter counts on carcasses, the situation has been improving continuously over the last few years, even if 2·5% of the carcasses are still contaminated by more than 1000 Campylobacter per g of skin. Although the current control system focusing on Salmonella is based on firm epidemiologic data and offers effective means of control (e.g. slaughtering of positive breeder flocks), existing information on Campylobacter makes it more difficult to formulate an effective control plan for free-range broilers, due to their particular exposure to environmental contamination. This long-term surveillance programme provided an extended view of the evolution of the contamination of free-range broilers and a direct measurement of the impact of mandatory and profession-driven interventions on the microbiological quality of carcasses. © 2016 The Society for Applied Microbiology.

Stability of safety glasses during sterilization and disinfection.

PubMed

Gleason, M J; Molinari, J A

1987-07-01

Awareness of the necessity for physical barriers as essential components of an infection control program for dental practice has led to increased use of gloves, masks, and protective eyewear. Because eyewear is not disposable, it could serve as a source of cross-contamination and should be disinfected between patients. This study investigates the optical stability of two types of safety glasses after various sterilization/disinfection procedures.

Removal site evaluation report for the Isotope Facilities at Oak Ridge National Laboratory, Oak Ridge, Tennessee

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

NONE

This removal site evaluation (RmSE) report of the Isotope Facilities at Oak Ridge National Laboratory (ORNL) was prepared to provide the Environmental Restoration Program with information necessary to evaluate whether hazardous and/or radiological contaminants in and around the Isotopes Facility pose a substantial risk to human health or the environment and if remedial site evaluations (RSEs) or removal actions are required. The scope of the project included: (1) a review of historical evidence regarding operations and use of the facility; (2) interviews with facility personnel concerning current and past operating practices; (3) a site inspection; and (4) identification of hazardmore » areas requiring maintenance, removal, or remedial actions. The results of RmSE indicate that no substantial risks exist from contaminants present in the Isotope Facilities because adequate controls and practices exist to protect human health and the environment. The recommended correction from the RmSE are being conducted as maintenance actions; accordingly, this RmSE is considered complete and terminated.« less

Catering Gluten-Free When Simultaneously Using Wheat Flour.

PubMed

Miller, Kathryn; McGough, Norma; Urwin, Heidi

2016-02-01

A European law on gluten-free (GF) labeling came into force in 2012, covering foods sold prepacked and in food service establishments, and a similar U.S. Food and Drug Administration (FDA) regulation covers GF labeling from August 2014. Gluten is found in the grains wheat, rye, and barley. A common source of gluten in the kitchen is wheat flour. This research aimed to determine variables that have a significant effect on gluten contamination in commercial kitchens when wheat flour is in use and to establish controls necessary to assure GF production. A pilot study was used to test the following hypotheses: (i) increasing duration of exposure to wheat flour would increase gluten contamination, (ii) increasing distance between the site of preparation and the site of wheat flour would reduce gluten contamination, (iii) the use of a ventilation hood would decrease gluten contamination, and (iv) the use of a barrier segregating the site of preparation of a GF meal and the use of wheat flour would decrease gluten contamination. Petri dishes containing GF rice pudding were placed in three directions at increasing distances (0.5 to 2 m) from a site of wheat flour use. A barrier was in place between a third of samples and the site of wheat flour. After wheat flour was handled for 0.5 and 4.0 h, petri dishes were sealed and the contents were analyzed for gluten. The experiment was duplicated with the ventilation hood on and off. The pilot study revealed that a distance of 2 m from the use of wheat flour was required to control gluten contamination at ≤20 ppm if wheat flour had been in use for 4.0 h. The identified control of distance was tested in five different study sites. In each of the study sites, a test meal was prepared a minimum of 2 m away from the site of wheat flour use. Although kitchens vary and must be considered individually, the established control of a minimum 2 m distance, along with good hygiene practices, was found to be effective in preparing GF meals at all five study sites.

A Geochemical Reaction Model for Titration of Contaminated Soil and Groundwater at the Oak Ridge Reservation

NASA Astrophysics Data System (ADS)

Zhang, F.; Parker, J. C.; Gu, B.; Luo, W.; Brooks, S. C.; Spalding, B. P.; Jardine, P. M.; Watson, D. B.

2007-12-01

This study investigates geochemical reactions during titration of contaminated soil and groundwater at the Oak Ridge Reservation in eastern Tennessee. The soils and groundwater exhibits low pH and high concentrations of aluminum, calcium, magnesium, manganese, various trace metals such as nickel and cobalt, and radionuclides such as uranium and technetium. The mobility of many of the contaminant species diminishes with increasing pH. However, base additions to increase pH are strongly buffered by various precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior and associated geochemical effects is thus critical to evaluate remediation performance of pH manipulation strategies. This study was undertaken to develop a practical but generally applicable geochemical model to predict aqueous and solid-phase speciation during soil and groundwater titration. To model titration in the presence of aquifer solids, an approach proposed by Spalding and Spalding (2001) was utilized, which treats aquifer solids as a polyprotic acid. Previous studies have shown that Fe and Al-oxyhydroxides strongly sorb dissolved Ni, U and Tc species. In this study, since the total Fe concentration is much smaller than that of Al, only ion exchange reactions associated with Al hydroxides are considered. An equilibrium reaction model that includes aqueous complexation, precipitation, ion exchange, and soil buffering reactions was developed and implemented in the code HydroGeoChem 5.0 (HGC5). Comparison of model results with experimental titration curves for contaminated groundwater alone and for soil- water systems indicated close agreement. This study is expected to facilitate field-scale modeling of geochemical processes under conditions with highly variable pH to develop practical methods to control contaminant mobility at geochemically complex sites.

COMBINATION OF A SOURCE REMOVAL REMEDY AND BIOREMEDIATION FOR THE TREATMENT OF A TCE CONTAMINATED AQUIFER

EPA Science Inventory

Historical disposal practices of chlorinated solvents have resulted in the widespread contamination of ground-water resources. These ground-water contaminants exist in the subsurface as free products, residual and vapor phases, and in solution. The remediation of these contamin...

Lessons Learned from the Hubble Space Telescope (HST) Contamination Control Program

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.; Townsend, Jacqueline A.; Hedgeland, Randy J.

2004-01-01

Over the past two decades, the Hubble Space Telescope (HST) Contamination Control Program has evolved from a ground-based integration program to a space-based science-sustaining program. The contamination controls from the new-generation Scientific Instruments and Orbital Replacement Units were incorporated into the HST Contamination Control Program to maintain scientific capability over the life of the telescope. Long-term on-orbit scientific data has shown that these contamination controls implemented for the instruments, Servicing Mission activities (Orbiter, Astronauts, and mission), and on-orbit operations successfully protected the HST &om contamination and the instruments from self-contamination.

Lessons Learned from the Hubble Space Telescope (HST) Contamination Control Program

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.; Townsend, Jacqueline A.; Hedgeland, Randy J.

2004-01-01

Over the past two decades, the Hubble Space Telescope (HST) Contamination Control Program has evolved from a ground-based integration program to a space-based science-sustaining program. The contamination controls from the new-generation Scientific Instruments and Orbital Replacement Units were incorporated into the HST Contamination Control Program to maintain scientific capability over the life of the telescope. Long-term on-orbit scientific data has shown that these contamination controls implemented for the instruments, Servicing Mission activities (Orbiter, Astronauts, and mission), and on-orbit operations successfully protected the HST from contamination and the instruments from self-contamination.

Intensive (pasture) beef cattle operations: the perspective of New Zealand.

PubMed

Hathaway, S C

1997-08-01

Beef production in New Zealand has characteristics typical of a temperate climate and pasture-based animal husbandry. The specific pathogens which may contaminate fresh beef and which are empirically considered to be of public health importance are similar to those in other countries with temperate climates, i.e. Salmonella, Campylobacter, Escherichia coli O157:H7, Listeria monocytogenes and Toxoplasma gondii. With the exception of T. gondii, it is likely that almost all transmission of these hazards through consumption of beef results from unseen microbial cross-contamination from gastrointestinal sources during slaughter, dressing and further processing. Gaining comprehensive information on carcass contamination levels is an essential first step in establishing food safety objectives for a particular beef production system, and in designing risk-based hazard analysis and critical control point (HACCP) plans. It is likely that the lower mean and maximum numbers of indicator micro-organisms on New Zealand carcasses (when compared with other countries) are in part due to the pre-slaughter cleanliness status of cattle reared under temperate, pasture conditions. Similarly, the failure to detect specific pathogens of gastrointestinal origin in a comprehensive baseline survey most probably reflects the limited pathway for faecal contamination during slaughter and dressing under processing conditions in New Zealand. The New Zealand example provides strong evidence for the need to design HACCP plans according to the specific national (or regional) situation. Reducing all pathways for faecal contamination of products to the maximum extent practicable will be the most important factor in achieving desired food safety objectives for fresh beef. Variable densities of microbial pathogens in gastrointestinal contents are also likely to have a significant effect on subsequent contamination levels of beef carcasses: however, effective controls for limiting the presence of most pathogens of concern in the live animal have yet to be identified.

Tenax TA extraction to understand the rate-limiting factors in methyl-β-cyclodextrin-enhanced bioremediation of PAH-contaminated soil.

PubMed

Sun, Mingming; Luo, Yongming; Teng, Ying; Christie, Peter; Jia, Zhongjun; Li, Zhengao

2013-06-01

The effectiveness of many bioremediation systems for PAH-contaminated soil may be constrained by low contaminant bioaccessibility due to limited aqueous solubility or large sorption capacity. Information on the extent to which PAHs can be readily biodegraded is of vital importance in the decision whether or not to remediate a contaminated soil. In the present study the rate-limiting factors in methyl-β-cyclodextrin (MCD)-enhanced bioremediation of PAH-contaminated soil were evaluated. MCD amendment at 10 % (w/w) combined with inoculation with the PAH-degrading bacterium Paracoccus sp. strain HPD-2 produced maximum removal of total PAHs of up to 35 %. The desorption of PAHs from contaminated soil was determined before and after 32 weeks of bioremediation. 10 % (w/w) MCD amendment (M2) increased the Tenax extraction of total PAHs from 12 to 30 % and promoted degradation by up to 26 % compared to 6 % in the control. However, the percentage of Tenax extraction for total PAHs was much larger than that of degradation. Thus, in the control and M2 treatment it is likely that during the initial phase the bioaccessibility of PAHs is high and biodegradation rates may be limited by microbial processes. On the other hand, when the soil was inoculated with the PAH-degrading bacterium (CKB and MB2), the slowly and very slowly desorbing fractions (F sl and F vl ) became larger and the rate constants of slow and very slow desorption (k sl and k vl ) became extremely small after bioremediation, suggesting that desorption is likely rate limiting during the second, slow phase of biotransformation. These results have practical implications for site risk assessment and cleanup strategies.

Agricultural and Management Practices and Bacterial Contamination in Greenhouse versus Open Field Lettuce Production

PubMed Central

Holvoet, Kevin; Sampers, Imca; Seynnaeve, Marleen; Jacxsens, Liesbeth; Uyttendaele, Mieke

2014-01-01

The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards. PMID:25546272

Agricultural and management practices and bacterial contamination in greenhouse versus open field lettuce production.

PubMed

Holvoet, Kevin; Sampers, Imca; Seynnaeve, Marleen; Jacxsens, Liesbeth; Uyttendaele, Mieke

2014-12-23

The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards.

Effectiveness of practices to reduce blood culture contamination: a Laboratory Medicine Best Practices systematic review and meta-analysis.

PubMed

Snyder, Susan R; Favoretto, Alessandra M; Baetz, Rich Ann; Derzon, James H; Madison, Bereneice M; Mass, Diana; Shaw, Colleen S; Layfield, Christopher D; Christenson, Robert H; Liebow, Edward B

2012-09-01

This article is a systematic review of the effectiveness of three practices for reducing blood culture contamination rates: venipuncture, phlebotomy teams, and prepackaged preparation/collection (prep) kits. The CDC-funded Laboratory Medicine Best Practices Initiative systematic review methods for quality improvement practices were used. Studies included as evidence were: 9 venipuncture (vs. versus intravenous catheter), 5 phlebotomy team; and 7 prep kit. All studies for venipuncture and phlebotomy teams favored these practices, with meta-analysis mean odds ratios for venipuncture of 2.69 and phlebotomy teams of 2.58. For prep kits 6 studies' effect sizes were not statistically significantly different from no effect (meta-analysis mean odds ratio 1.12). Venipuncture and the use of phlebotomy teams are effective practices for reducing blood culture contamination rates in diverse hospital settings and are recommended as evidence-based "best practices" with high overall strength of evidence and substantial effect size ratings. No recommendation is made for or against prep kits based on uncertain improvement. Copyright © 2012 The Canadian Society of Clinical Chemists. All rights reserved.

Risk of contamination of nasal sprays in otolaryngologic practice

PubMed Central

Aydin, Erdinc; Hizal, Evren; Akkuzu, Babur; Azap, Ozlem

2007-01-01

Background Reusable nasal-spray devices are frequently used in otolaryngologic examinations, and there is an increasing concern about the risk of cross-contamination from these devices. The aim of our study was to determine, by means of microbiologic analysis, the safety of a positive-displacement or pump-type atomizer after multiple uses. Methods A reusable nasal spray bottle, pump, and tips were used in the nasal physical examination of 282 patients admitted to a tertiary otolaryngology clinic. The effectiveness of 2 different methods of prophylaxis against microbiologic contamination (the use of protective punched caps or rinsing the bottle tip with alcohol) was compared with that of a control procedure. Results Although there was no statistically significant difference in positive culture rates among the types of nasal spray bottles tested, methicillin-resistant coagulase-negative staphylococci were isolated in 4 of 198 cultures. Conclusion Given these findings, we concluded that additional precautions (such as the use of an autoclave between sprays, disposable tips, or disposable devices) are warranted to avoid interpatient cross-contamination from a reusable nasal spray device. PMID:17352835

Using Optically Stimulated Electron Emission as an Inspection Method to Monitor Surface Contamination

NASA Technical Reports Server (NTRS)

Lingbloom, Mike S.

2008-01-01

During redesign of the Space Shuttle reusable solid rocket motor (RSRM), NASA amended the contract with ATK Launch Systems (then Morton Thiokol Inc.) with Change Order 966 to implement a contamination control and cleanliness verification method. The change order required: (1) A quantitative inspection method (2) A written record of actual contamination levels versus a known reject level (3) A method that is more sensitive than existing methods of visual and black light inspection. Black light inspection is only useful for inspection of contaminants that fluoresce near the 365 nm spectral line and is not useful for inspection of most silicones that will not produce strong fluorescence. Black light inspection conducted by a qualified inspector under controlled light is capable of detecting Conoco HD-2 grease in gross amounts and is very subjective due to operator sensitivity. Optically stimulated electron emission (OSEE), developed at the Materials and Process Laboratory at Marshall Space Flight Center (MSFC), was selected to satisfy Change Order 966. OSEE offers several important advantages over existing laboratory methods with similar sensitivity, e.g., spectroscopy and nonvolatile residue sampling, which provide turn around time, real time capability, and full coverage inspection capability. Laboratory methods require sample gathering and in-lab analysis, which sometimes takes several days to get results. This is not practical in a production environment. In addition, these methods do not offer full coverage inspection of the large components

Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users

PubMed Central

Thakur, Deeksha V.; Gaikwad, Ujjwala N.

2014-01-01

Background & objectives: With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmic infections. Methods: Four samples each from 50 participants (n=200) were collected from the lenses, lens care solutions, lens care solution bottles and lens cases along with a questionnaire regarding their lens use. The samples were inoculated onto sheep blood agar, Mac Conkey's agar and Sabouraud's dextrose agar. Organisms were identified using standard laboratory protocols. Results: Overall rate of microbial contamination among the total samples was 52 per cent. The most and the least contaminated samples were found to be lens cases (62%) and lens care solution (42%), respectively. The most frequently isolated contaminant was Staphylococcus aureus (21%) followed by Pseudomonas species (19.5%). Majority (64%) of the participants showed medium grade of compliance to lens cleaning practices. Rate of contamination was 100 and 93.75 per cent respectively in those participants who showed low and medium compliance to lens care practices as compared to those who had high level of compliance (43.75%) (P<0.05). Interpretation & conclusions: Lens care practices amongst the participants were not optimum which resulted into high level contamination. Hence, creating awareness among the users about the lens care practices and regular cleaning and replacements of lens cases are required. PMID:25297366

Waste Isolation Pilot Plant Salt Decontamination Testing

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

Demmer, Ricky Lynn; Reese, Stephen Joseph

2015-03-01

On February 14, 2014, americium and plutonium contamination was released in the Waste Isolation Pilot Plant (WIPP) salt caverns. Several practical, easily deployable methods of decontaminating WIPP salt, using a surrogate contaminant and americium (241Am), were developed and tested. The effectiveness of the methods is evaluated qualitatively, and to the extent practical, quantitatively. Of the methods tested (dry brushing, vacuum cleaning, water washing, mechanical grinding, strippable coatings, and fixative barriers), the most practical seems to be water washing. Effectiveness is very high, and water washing is easy and rapid to deploy. The amount of wastewater produced (~2 L/m2) would bemore » substantial and may not be easy to manage, but the method is the clear winner from a usability perspective. Removable surface contamination levels (smear results) from water washed coupons found no residual removable contamination. Thus, whatever contamination is left is likely adhered to (or trapped within) the salt. The other option that shows promise is the use of a fixative barrier. Bartlett Nuclear, Inc.’s Polymeric Barrier System proved the most durable of the coatings tested. The coatings were not tested for contaminant entrapment, only for coating integrity and durability.« less

Foliar sorption of emerging and priority contaminants under controlled conditions.

PubMed

Calderón-Preciado, Diana; Matamoros, Víctor; Biel, Carmen; Save, Robert; Bayona, Josep M

2013-09-15

Agricultural irrigation water contains a variety of contaminants that can be introduced into the food chain through intake by irrigated crops. This paper describes an experiment under controlled conditions designed to simulate sprinkle irrigation with polluted water at two different relative humidities (40 and 90%). Specifically, shed lettuce-heart leaves were spiked with an aqueous solution containing organic microcontaminants, including pharmaceuticals (ibuprofen, diclofenac, clofibric acid, and carbamazepine), fragrances (tonalide), biocides (triclosan), insecticides (lindane), herbicides (atrazine), phenolic estrogen (bisphenol A), and polycyclic aromatic hydrocarbons (phenanthrene and pyrene). Following an incubation period (48 h), the treated leaves were rinsed with water, and both the solution used to rinse them and the leaves themselves were independently analyzed to investigate the foliar sorption and uptake of the spiked organic contaminants through cuticle. The results showed that the foliar sorption of emerging and priority microcontaminants in leaves wetted by irrigation practices is related to their polarity (logD(ow)) and volatility (logk(H)), regardless of their compound class and the relative humidity. The results thus underscore the need to improve the quality of reclaimed water in crop irrigation, particularly when sprinkle irrigation is used. Copyright © 2013 Elsevier B.V. All rights reserved.

Economic analysis of recycling contaminated concrete

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

Stephen, A.; Ayers, K.W.; Boren, J.K.

1997-02-01

Decontamination and Decommissioning activities in the DOE complex generate large volumes of radioactively contaminated and uncontaminated concrete. Currently, this concrete is usually decontaminated, the contaminated waste is disposed of in a LLW facility and the decontaminated concrete is placed in C&D landfills. A number of alternatives to this practice are available including recycling of the concrete. Cost estimates for six alternatives were developed using a spreadsheet model. The results of this analysis show that recycling alternatives are at least as economical as current practice.

Assessing the status of food safety management systems for fresh produce production in East Africa: evidence from certified green bean farms in Kenya and noncertified hot pepper farms in Uganda.

PubMed

Nanyunja, J; Jacxsens, L; Kirezieva, K; Kaaya, A N; Uyttendaele, M; Luning, P A

2015-06-01

The farms of fresh produce farmers are major sources of food contamination by microbiological organisms and chemical pesticides. In view of their choice for farming practices, producers are influenced by food safety requirements. This study analyzes the role of food safety standard certification toward the maturity of food safety management systems (FSMS) in the primary production of fresh produce. Kenya and Uganda are two East African countries that export green beans and hot peppers, respectively, to the European Union but have contrasting features in terms of agricultural practices and certification status. In the fresh produce chain, a diagnostic instrument for primary production was used to assess context factors, core control and assurance activities, and system output to measure the performance of FSMS for certified green bean farms in Kenya and noncertified hot pepper farms in Uganda. Overall, our findings show that in Uganda, noncertified hot pepper farms revealed only a "basic level of control and assurance" activities in their FSMS, which was not satisfactory, because no insight into potential pesticide microbial contamination was presented by these farmers. On the other hand, certified green bean farms in Kenya had an "average level of control and assurance," providing insight into the delivered food safety and quality by the farmers. Farm size did not impact the maturity level of FSMS. This study confirms the role played by food safety standard certification toward the maturity of FSMS implemented in developing countries and demonstrates the possibility of Ugandan farms to upgrade agricultural practices in the fresh produce sector.

Egg Safety in the Realm of Preharvest Food Safety.

PubMed

Singh, Manpreet; Brar, Jagpinder

2016-08-01

Eggs are nutritious, yet they are a highly perishable commodity like other protein sources such as meat. Even though steps are taken all along the production process of shell eggs, from farm to table, the potential for contamination of the shells and egg contents poses a high risk to consumers. The main sources of contamination can be categorized as vertical transmission, in which the layers can be carriers of pathogens and can pass them on during egg formation, and horizontal transmission, in which environmental factors such as water, feed, layer houses, and personnel are the main source of contamination. Ongoing preharvest practices might not be enough to completely eliminate pathogens from shell eggs; however, consistently following good practices along with proper handling during transportation and retail sale and by consumers can be significant in reducing the risk. This article discusses the various aspects of production practices, their potential for cross-contamination, and decontamination technologies for shell eggs.

Minimizing Sources of Airborne, Aerosolized, and Contact Contaminants in the OR Environment.

PubMed

Armellino, Donna

2017-12-01

Surgical site infections are unintended consequences of surgery that can cause harm to patients and place financial burdens on health care organizations. Extrinsic factors in the OR-including health care providers' behavior and practices that modify air movement, the physical environment, equipment, or surgical instruments-can increase microbial contamination. Microbes can be transported into the surgical incision by airborne or contact routes and contribute to a surgical site infection. Simple practices to prevent infection-such as minimizing airborne particles and contaminants, maintaining equipment according to the manufacturer's recommendations, cleaning and disinfecting the environment and surgical instruments, and performing proper hand hygiene-can reduce the degree of microbial contamination. Perioperative leaders and health care providers can help decrease the patient's risk of surgical site infection with proactive preventive practices that break the chain of infection. Copyright © 2017 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Evaluation of nonpoint-source contamination, Wisconsin; selected streamwater-quality data, land-use and best-management practices inventory, and quality assurance and quality control, water year 1993

USGS Publications Warehouse

Corsi, Steven R.; Walker, John F.; Graczyk, D.J.; Greb, S.R.; Owens, D.W.; Rappold, K.F.

1995-01-01

A special study was done to determine the effect of holding time on fecal coliform colony counts. A linear regression indicated that the mean decrease in colony counts over 72 hours was 8.2 percent per day. Results after 24 hours showed that colony counts increased in some samples and decreased in others.

Correlation of the Hubble Space Telescope (HST) Space Telescope Imaging Spectrometer (STIS) On-Orbit Data with Pre-launch Predictions and Ground Contamination Controls

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.

2003-01-01

The Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) was deployed on-orbit in February 1997. The contamination program for STIS was stringently controlled as the five-year end-of-life deposition was set at 158, per optical element. Contamination was controlled through materials selection, extensive vacuum outgassing certifications, cleaning techniques, and environmental controls. In addition to ground contamination controls, on-orbit contamination controls were implemented for both the HST servicing mission activities and early post-servicing mission checkout. The extensive contamination control program will be discussed and the STIS on-orbit data will be correlated with the prelaunch analytical predictions.

Quantification of contamination levels and particular risk of Salmonella spp. in pigs in slaughterhouses in Chiang Mai and Lamphun provinces, Thailand.

PubMed

Tadee, Pakpoom; Boonkhot, Phacharaporn; Patchanee, Prapas

2014-11-01

Salmonella spp. is one of the important foodborne pathogens, and the slaughtering process is recognized as a potential point of contamination and the spread of the pathogens. The three objectives of this study are first, to quantify the contamination levels of Salmonella spp. in pig skins and carcasses, second, to evaluate the outcomes from different pig supply sources and different practices at three critical steps (scalding, splitting, and washing) for Salmonella spp. contamination, and third, to assess risk of Salmonella spp. contamination in pork products after slaughtering level. The study was performed in three representative slaughterhouses in Chiang Mai and Lamphun provinces, Thailand. Investigation conducted from May 2013 through October 2013 found the overall prevalence and contamination levels mean to be 11.85% and 0.34 MPN/cm2, respectively. There was no statistically significant in Salmonella spp. prevalence and contamination levels detected with different patterns at the slaughterhouses which were supplied pigs from either co-operative or integrated farms. Factors found to reduce Salmonella spp. loads on carcasses included good practices, e.g., regular changing of water in the scalding tank after each batch and the use of chlorine in the washing step. Risk of Salmonella spp. contamination of pork products at the final stage of slaughtering was nearly 10%. Good practices and proper hygiene measures should be applied to minimize the risk of Salmonella spp. exposure in the slaughtering line, which can reduce the contamination pressure downstream at retail shops as well as for end consumers.

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.

Sources and Practices Contributing to Soil Contamination

Treesearch

A.S. Knox; A.P. Gamerdinger; D.C. Adriano; R.K. Kolka; D.I. Kaplan

1999-01-01

The term soil contamination can have different connotations because anthropogehic sources of contaminants have affected virtually every natural ecosystem in the world; a commonly held view is that contamination occurs when the soil composition deiiates from the normal composition (Adriano et al., 1997). Other specialists have defined soil pollution as the presence of...

Restaurant industry preparedness against intentional food contamination: results of a South Carolina survey.

PubMed

Xirasagar, Sudha; Kanwat, C P; Smith, Lillian U; Li, Yi-Jhen; Sros, Lekhena; Shewchuk, Richard M

2010-01-01

Food safety and food defense are both responsibilities of public health agencies. Food safety practices within restaurants are regulated by state and local public health laws based on the US Food and Drug Administration Model Food Code. However, little is known about preemptive practices against intentional food-borne outbreaks within restaurants. The researchers administered a survey to a 50 percent random sample of South Carolina's restaurants, a state that relies heavily on tourism and the restaurant industry for its economic well-being. The survey received a response rate of 15 percent. The food defense practice items fall under three functional categories: employee management and training practices; vendor and delivery-related practices; and physical facilities and operational security practices. This study presents the results, classified by geographic region. Findings indicate some key areas of vulnerability that need attention to protect the public from mass food outbreaks due to intentional contamination. Of concern, there is much variation in practices by geographic region. On the basis of the survey, recommendations are made to improve restaurant preparedness against food-borne outbreaks from terrorism and malevolent contamination.

Effectiveness of practices to reduce blood culture contamination: A Laboratory Medicine Best Practices systematic review and meta-analysis☆

PubMed Central

Snyder, Susan R.; Favoretto, Alessandra M.; Baetz, Rich Ann; Derzon, James H.; Madison, Bereneice M.; Mass, Diana; Shaw, Colleen S.; Layfield, Christopher D.; Christenson, Robert H.; Liebow, Edward B.

2015-01-01

Objectives This article is a systematic review of the effectiveness of three practices for reducing blood culture contamination rates: venipuncture, phlebotomy teams, and prepackaged preparation/collection (prep) kits. Design and methods The CDC-funded Laboratory Medicine Best Practices Initiative systematic review methods for quality improvement practices were used. Results Studies included as evidence were: 9 venipuncture (vs. versus intravenous catheter), 5 phlebotomy team; and 7 prep kit. All studies for venipuncture and phlebotomy teams favored these practices, with meta-analysis mean odds ratios for venipuncture of 2.69 and phlebotomy teams of 2.58. For prep kits 6 studies’ effect sizes were not statistically significantly different from no effect (meta-analysis mean odds ratio 1.12). Conclusions Venipuncture and the use of phlebotomy teams are effective practices for reducing blood culture contamination rates in diverse hospital settings and are recommended as evidence-based “best practices” with high overall strength of evidence and substantial effect size ratings. No recommendation is made for or against prep kits based on uncertain improvement. PMID:22709932

Contamination of tomatoes with coliforms and Escherichia coli on farms and in markets of northwest Nigeria.

PubMed

Shenge, Kenneth C; Whong, Clement M Z; Yakubu, Lydia L; Omolehin, Raphael A; Erbaugh, J Mark; Miller, Sally A; LeJeune, Jeffrey T

2015-01-01

Although recent reports indicated that produce contamination with foodborne pathogens is widespread in Nigeria, the sources and magnitude of microbial contamination of fruits and vegetables on farms and in markets have not been thoroughly identified. To ascertain possible pathways of contamination, the frequency and magnitude of coliform and Escherichia coli contamination of tomatoes produced in northwest Nigeria was assessed on farms and in markets. Eight hundred twenty-six tomato fruit samples and 36 irrigation water samples were collected and assessed for fecal indicator organisms. In addition, the awareness and use of food safety practices by tomato farmers and marketers were determined. Median concentration of coliforms on all field- and market-sourced tomato fruit samples, as well as in irrigation water sources, in Kaduna, Kano, and Katsina states exceeded 1,000 most probable number (MPN) per g. Median E. coli counts from 73 (17%) of 420 field samples and 231 (57%) of 406 market tomato fruit samples exceeded 100 MPN/g. Median E. coli concentrations on tomato fruits were higher (P < 0.01) in the rainy season (2.45 Log MPN/g), when irrigation was not practiced than in the dry (1.10 Log MPN/g) and early dry (0.92 Log MPN/g) seasons. Eighteen (50%) of 36 irrigation water samples had E. coli counts higher than 126 MPN/100 ml. Median E. coli contamination on market tomato fruit samples (2.66 Log MPN/g) were higher (P < 0.001) than those from tomatoes collected on farms (0.92 Log MPN/g). Farmers and marketers were generally unaware of the relationship between food safety practices and microbial contamination on fresh produce. Good agricultural practices pertaining to food safety on farms and in local markets were seldom used. Adoption of food safety practices on-farm, during transport, and during marketing could improve the microbial quality of tomatoes available to the public in this region of the world.

30 CFR 56.5005 - Control of exposure to airborne contaminants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by prevention...

Elimination of high titre HIV from fibreoptic endoscopes.

PubMed

Hanson, P J; Gor, D; Jeffries, D J; Collins, J V

1990-06-01

Concern about contamination of fibreoptic endoscopes with human immunodeficiency virus (HIV) has generated a variety of disruptive and possibly unnecessary infection control practices in endoscopy units. Current recommendations on the cleaning and disinfection of endoscopes have been formulated without applied experimental evidence of the effective removal of HIV from endoscopes. To study the kinetics of elimination of HIV from endoscope surfaces, we artificially contaminated the suction-biopsy channels of five Olympus GIF XQ20 endoscopes with high titre HIV in serum. The air and water channels of two instruments were similarly contaminated. Contamination was measured by irrigating channels with viral culture medium and collecting 3 ml at the distal end for antigen immunoassay. Endoscopes were then cleaned manually in neutral detergent according to the manufacturer's recommendations and disinfected in 2% alkaline glutaraldehyde (Cidex, Surgikos) for two, four, and ten minutes. Contamination with HIV antigens was measured before and after cleaning and after each period of disinfection. Initial contamination comprised 4.8 x 10(4) to 3.5 x 10(6) pg HIV antigen/ml. Cleaning in detergent achieved a reduction to 165 pg/ml (99.93%) on one endoscope and to undetectable levels (100%) on four. After two minutes in alkaline glutaraldehyde all samples were negative and remained negative after the longer disinfection times. Air and water channels, where contaminated, were tested after 10 minutes' disinfection and were negative. These findings underline the importance of cleaning in removing HIV from endoscope and indicate that the use of dedicated equipment and long disinfection times are unnecessary.

Monitoring radionuclide contamination in the unsaturated zone - Lessons learned at the Amargosa Desert Research Site, Nye County, Nevada

USGS Publications Warehouse

Stonestrom, David A.; Abraham, Jared D.; Andraski, Brian J.; Baker, Ronald J.; Mayers, C. Justin; Michel, Robert L.; Prudic, David E.; Striegl, Robert G.; Walvoord, Michelle Ann

2004-01-01

Contaminant-transport processes are being investigated at the U.S. Geological Survey’s Amargosa Desert Research Site (A DRS), adjacent to the Nation’s first commercial disposal facility for low-level radioactive waste. Gases containing tritium and radiocarbon are migrating through a 110-m thick unsaturated zone from unlined trenches that received waste from 1962 to 1992. Results relevant to long- term monitoring of radionuclides are summarized as follows. Contaminant plumes have unexpected histories and spatial configurations due to uncertainties in the: (1) geologic framework, (2) biochemical reactions involving waste components, (3) interactions between plume components and unsaturated-zone materials, (4) disposal practices, and (5) physical transport processes. Information on plume dynamics depends on ex-situ wet-chemical techniques because in-situ sensors for the radionuclides of interest do not exist. As at other radioactive-waste disposal facilities, radionuclides at the ADRS are mixed with varying amounts of volatile organic compounds (VOCs). Carbon-dioxide and VOC anomalies provide proxies for radioactive contamination. Contaminants in the unsaturated zone migrate along preferential pathways. Effective monitoring thus requires accurate geologic characterization. Direct- current electrical-resistivity imaging successfully mapped geologic units controlling preferential transport at the ADRS. Direct sampling of water from the unsaturated zone is complex and time consuming. Sampling plant water is an efficient alternative for mapping shallow tritium contamination.

Handling Practices of Fresh Leafy Greens in Restaurants: Receiving and Training†

PubMed Central

COLEMAN, ERIK; DELEA, KRISTIN; EVERSTINE, KAREN; REIMANN, DAVID; RIPLEY, DANNY

2015-01-01

Multiple foodborne illness outbreaks have been associated with the consumption of fresh produce. Investigations have indicated that microbial contamination throughout the farm-to-fork continuum often contributed to these outbreaks. Researchers have hypothesized that handling practices for leafy greens in restaurants may support contamination by and proliferation and amplification of pathogens that cause foodborne illness outbreaks. However, limited data are available on how workers handle leafy greens in restaurants. The purpose of this study was to collect descriptive data on handling practices of leafy greens in restaurants, including restaurant characteristics, types of leafy greens used, produce receipt, and food safety training and certification. As a federal collaborative partner with the Environmental Health Specialists Network (EHS-Net) of the Centers for Disease Control and Prevention, the U.S. Food and Drug Administration (FDA) recommended that EHS-Net participants survey handling practices for leafy greens in restaurants. The recommendations in the FDA’s Guide to Minimize Microbial Food Safety Hazards of Leafy Greens are significant to this study for comparison of the results. The survey revealed that appropriate handling procedures assist in the mitigation of other unsafe handling practices for leafy greens. These results are significant because the FDA guidance for the safe handling of leafy greens was not available until 2009, after the survey had been completed. The information provided from this study can be used to promote additional efforts that will assist in developing interventions to prevent future foodborne illness outbreaks associated with leafy greens. PMID:24290691

Ineffective hand washing and the contamination of carrots after using a field latrine.

PubMed

Monaghan, J M; Hutchison, M L

2016-04-01

A study was undertaken to simulate the likely effects of a field worker with poor hygienic practices that had returned to work too soon after recovering from an infection by an enteric pathogen. The studies simulated a variety of hand-washing practices from no washing to washing with soap and water followed by an application of alcohol gel after using a field latrine. The numbers of generic Escherichia coli isolated from workers' hands declined with increasing thoroughness of hand-washing treatments with unwashed hands > water > water and soap > water, soap and alcohol gel. Where gloves were worn the counts obtained for the treatments were significantly reduced, but it was observed that unwashed hands contaminated gloves during the process of putting them on. Hand contamination following the use of a field latrine transferred contamination to carrots. These results suggest that if no gloves are worn it would be best practice to wash hands with water and soap and apply alcohol gel after using a field latrine. Wearing gloves reduced the risk of contaminating handled produce but workers should still wash their hands after using a field latrine before applying gloves. This study shows that inadequate hand hygiene in the field following the use of a field latrine can transfer bacterial contamination to hand-harvested carrots. Where fresh produce crops are to be handled by workers, wearing gloves reduces the risk of contaminating produce but workers should still wash their hands after using a field latrine before applying gloves. If no gloves are worn it would be best practice to wash hands with water and soap and apply alcohol gel after using a field latrine. © 2016 The Society for Applied Microbiology.

Compliance with infection control practices in an university hospital dental clinic

PubMed Central

Mutters, Nico T.; Hägele, Ulrike; Hagenfeld, Daniel; Hellwig, Elmar; Frank, Uwe

2014-01-01

Aim: Compliance with infection control practices is the key to quality care and excellence in dentistry. Infection control remains one of the most cost-beneficial interventions available. However, implementing control procedures requires full compliance of the whole dental team. The aim of our study was to measure the compliance in daily clinical practice. Methods: The compliance with infection control practices in dentistry by dental health care personnel (DHCP) in a German university dental clinic was observed during clinical work. In addition, a survey was conducted to assess the individual knowledge about infection control procedures. Contamination of the workplace during invasive dental procedures was tested, as well. Results: A total of 58 invasive dental treatments implying close contacts between HCWs and patients were scrutinized. All HCWs (100%) wore gloves during dental work, but in some cases (female dentists: 14.3%; dental assistants: 28.6%) gloves were neither changed nor hands were disinfected between different activities or patient contacts (female dentists: 68.6%; male dentists: 60.9%; dental assistants: 93%). Only 31.4% of female and 39.1% of male dentists carried out adequate hygienic hand disinfection after removing gloves. Male dentists wore significantly more often (100%) protective eyewear compared to 77.1% of female dentists (p<0.05). In addition, most of female dentists (62.9%) and dental assistants (80.7%) wore jewelry during dental procedures. Conclusion: Despite the knowledge of distinct hygiene procedures only a small percentage of dental staff performs hygiene practices according to recommended guidelines. Strict audit is clearly needed in the dental setting to ensure compliance with infection control guidelines to prevent transmission of pathogens. Our results provide insights for the development of a targeted education and training strategy to enhance compliance of dental staff especially of dental assistants with infection control procedures. PMID:25285262

Compliance with infection control practices in an university hospital dental clinic.

PubMed

Mutters, Nico T; Hägele, Ulrike; Hagenfeld, Daniel; Hellwig, Elmar; Frank, Uwe

2014-01-01

Compliance with infection control practices is the key to quality care and excellence in dentistry. Infection control remains one of the most cost-beneficial interventions available. However, implementing control procedures requires full compliance of the whole dental team. The aim of our study was to measure the compliance in daily clinical practice. The compliance with infection control practices in dentistry by dental health care personnel (DHCP) in a German university dental clinic was observed during clinical work. In addition, a survey was conducted to assess the individual knowledge about infection control procedures. Contamination of the workplace during invasive dental procedures was tested, as well. A total of 58 invasive dental treatments implying close contacts between HCWs and patients were scrutinized. All HCWs (100%) wore gloves during dental work, but in some cases (female dentists: 14.3%; dental assistants: 28.6%) gloves were neither changed nor hands were disinfected between different activities or patient contacts (female dentists: 68.6%; male dentists: 60.9%; dental assistants: 93%). Only 31.4% of female and 39.1% of male dentists carried out adequate hygienic hand disinfection after removing gloves. Male dentists wore significantly more often (100%) protective eyewear compared to 77.1% of female dentists (p<0.05). In addition, most of female dentists (62.9%) and dental assistants (80.7%) wore jewelry during dental procedures. Despite the knowledge of distinct hygiene procedures only a small percentage of dental staff performs hygiene practices according to recommended guidelines. Strict audit is clearly needed in the dental setting to ensure compliance with infection control guidelines to prevent transmission of pathogens. Our results provide insights for the development of a targeted education and training strategy to enhance compliance of dental staff especially of dental assistants with infection control procedures.

10 CFR 835.1101 - Control of material and equipment.

Code of Federal Regulations, 2010 CFR

2010-01-01

....1101 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Radioactive Contamination Control... section, material and equipment in contamination areas, high contamination areas, and airborne radioactivity areas shall not be released to a controlled area if: (1) Removable surface contamination levels on...

Urine culture contamination: a College of American Pathologists Q-Probes study of 127 laboratories.

PubMed

Bekeris, Leonas G; Jones, Bruce Allen; Walsh, Molly K; Wagar, Elizabeth A

2008-06-01

While urine culture contamination may not be completely avoidable, some laboratories have lower contamination rates than others. A College of American Pathologists (CAP) 1998 Q-Probes study showed that many interventions commonly assumed to reduce contamination were not demonstrably effective. This article revisits the issue. To examine the frequency of urine culture contamination, review current laboratory practices in the collection of urine culture specimens, and determine practice characteristics that may be associated with the contamination rate. Laboratories participating in a CAP Q-Probes study were required to prospectively collect data on 120 consecutive urine culture specimens and provide information on the patient's demographics (age and sex), the location where the specimen was collected, how the specimen was handled, the number of isolates in quantities greater than or equal to 10,000 colony-forming units (CFU)/mL, and whether the laboratory considered the specimen to be contaminated. Specific inclusion and exclusion criteria were provided to the participants. Each laboratory completed a supplemental questionnaire that probed for specific laboratory urine culture collection practices. One hundred twenty-seven laboratories participated in the study. Results from a total of 14,739 urine specimens were received. For the purpose of this study, a urine specimen was determined to be contaminated if the culture yielded more than 2 isolates in quantities greater than or equal to 10,000 CFU/mL. Using these criteria the median institution had a contamination rate of 15.0%. Laboratories in the 10th percentile (low performance) had an average contamination rate of 41.7%, while laboratories in the 90th percentile had an average rate of 0.8%. The collection site had no influence on the contamination rate, but postcollection processing, especially refrigeration of the specimen, had a substantial effect. Providing instruction to patients produced a statistically significant lowering of contamination rates for specimens from male patients (P = .006) but not for female patients, except when written instructions were provided in the emergency room, in which case specimen contamination rates for both male and female patients dropped (P = .01). The median contamination rates remain at a level comparable to the results seen in a previous Q-Probes study, and some laboratories have very high contamination rates. Specimen refrigeration is associated with lower overall urine culture specimen contamination rate. Providing patient instruction is also associated with lower contamination rates under specific circumstances.

Evaluation methods for assessing effectiveness of in situ remediation of soil and sediment contaminated with organic pollutants and heavy metals.

PubMed

Song, Biao; Zeng, Guangming; Gong, Jilai; Liang, Jie; Xu, Piao; Liu, Zhifeng; Zhang, Yi; Zhang, Chen; Cheng, Min; Liu, Yang; Ye, Shujing; Yi, Huan; Ren, Xiaoya

2017-08-01

Soil and sediment contamination has become a critical issue worldwide due to its great harm to the ecological environment and public health. In recent years, many remediation technologies including physical, chemical, biological, and combined methods have been proposed and adopted for the purpose of solving the problems of soil and sediment contamination. However, current research on evaluation methods for assessing these remediation technologies is scattered and lacks valid and integrated evaluation methods for assessing the remediation effectiveness. This paper provides a comprehensive review with an environmental perspective on the evaluation methods for assessing the effectiveness of in situ remediation of soil and sediment contaminated with organic pollutants and heavy metals. The review systematically summarizes recent exploration and attempts of the remediation effectiveness assessment based on the content of pollutants, soil and sediment characteristics, and ecological risks. Moreover, limitations and future research needs of the practical assessment are discussed. These limitations are not conducive to the implementation of the abatement and control programs for soil and sediment contamination. Therefore, more attention should be paid to the evaluation methods for assessing the remediation effectiveness while developing new in situ remediation technologies in future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Skin decontamination: principles and perspectives.

PubMed

Chan, Heidi P; Zhai, Hongbo; Hui, Xiaoying; Maibach, Howard I

2013-11-01

Skin decontamination is the primary intervention needed in chemical, biological and radiological exposures, involving immediate removal of the contaminant from the skin performed in the most efficient way. The most readily available decontamination system on a practical basis is washing with soap and water or water only. Timely use of flushing with copious amounts of water may physically remove the contaminant. However, this traditional method may not be completely effective, and contaminants left on the skin after traditional washing procedures can have toxic consequences. This article focuses on the principles and practices of skin decontamination.

Foodborne protozoan parasites.

PubMed

Dawson, David

2005-08-25

This report addresses Cryptosporidium, Giardia, Cyclospora, and more briefly, Toxoplasma as the main parasitic protozoa of concern to food production worldwide. Other parasitic protozoa may be spread in food or water but are not considered as great a risk to food manufacture. The protozoan parasites Cryptosporidium, Giardia, and Cyclospora have proven potential to cause waterborne and foodborne disease. Toxoplasma gondii has been considered a risk in specific cases, but humans are not its primary host. Cryptosporidium and Giardia are widespread in the environment, particularly the aquatic environment, and major outbreaks of cryptosporidiosis and giardiasis have occurred as a result of contaminated drinking water. Large outbreaks of waterborne cyclosporiasis have not been identified. Cryptosporidium, Giardia, and Cyclospora have potential significance in the preparation and consumption of fresh produce and in catering practice, in which ready-to-eat foods may be served that have not received heat treatment. None of the three organisms Cryptosporidium, Giardia, and Cyclospora has been shown to be a problem for heat processed food or tap water that has undergone appropriate treatment at a water treatment works. All three are sensitive to standard pasteurisation techniques. Although humans are not a primary host for T. gondii, the potential exists for both waterborne and foodborne toxoplasmosis. Parasitic protozoa do not multiply in foods, but they may survive in or on moist foods for months in cool, damp environments. Their ecology makes control of these parasites difficult. For general control of parasitic protozoa in the food chain, the following steps are necessary: - Follow good hygienic practice in food service and catering industries.- Minimise dissemination of cysts and oocysts in the farming environment and via human waste management.- Include these microorganisms in Hazard Analysis Critical Control Point (HACCP) plans of water suppliers, industries or sectors that use fresh produce, and operations in which contaminated process or ingredient water could end up in the product (e.g., where water supplies may become contaminated).

NORM management in the oil and gas industry.

PubMed

Cowie, M; Mously, K; Fageeha, O; Nassar, R

2012-01-01

It has been established that naturally occurring radioactive material (NORM) may accumulate at various locations along the oil and gas production process. Components such as wellheads, separation vessels, pumps, and other processing equipment can become contaminated with NORM, and NORM can accumulate in the form of sludge, scale, scrapings, and other waste media. This can create a potential radiation hazard to workers, the general public, and the environment if certain controls are not established. Saudi Aramco has developed NORM management guidelines, and is implementing a comprehensive strategy to address all aspects of NORM management that aim to enhance NORM monitoring; control of NORM-contaminated equipment; control of NORM waste handling and disposal; and protection, awareness, and training of workers. The benefits of shared knowledge, best practice, and experience across the oil and gas industry are seen as key to the establishment of common guidance. This paper outlines Saudi Aramco's experience in the development of a NORM management strategy, and its goals of establishing common guidance throughout the oil and gas industry. Copyright © 2012. Published by Elsevier Ltd.

Improving water quality through California's Clean Beach Initiative: an assessment of 17 projects.

PubMed

Dorsey, John H

2010-07-01

California's Clean Beach Initiative (CBI) funds projects to reduce loads of fecal indicator bacteria (FIB) impacting beaches, thus providing an opportunity to judge the effectiveness of various CBI water pollution control strategies. Seventeen initial projects were selected for assessment to determine their effectiveness on reducing FIB in the receiving waters along beaches nearest to the projects. Control strategies included low-flow diversions, sterilization facilities, sewer improvements, pier best management practices (BMPs), vegetative swales, and enclosed beach BMPs. Assessments were based on statistical changes in pre- and postproject mean densities of FIB at shoreline monitoring stations targeted by the projects. Most low-flow diversions and the wetland swale project were effective in removing all contaminated runoff from beaches. UV sterilization was effective when coupled with pretreatment filtration and where effluent was released within a few hundred meters of the beach to avoid FIB regrowth. Other BMPs were less effective because they treated only a portion of contaminant sources impacting their target beach. These findings should be useful to other coastal states and agencies faced with similar pollution control problems.

Evaluation of beach grooming techniques on Escherichia coli density in foreshore sand at North Beach, Racine, WI

USGS Publications Warehouse

Kinzelman, Julie L.; Whitman, Richard L.; Byappanahalli, Muruleedhara N.; Jackson, Emma; Bagley, Robert C.

2003-01-01

Elevated levels of Escherichia coli(E. coli) in bathing waters at North Beach, a popular recreational site in Racine, Wisconsin, have been a persistent problem often resulting in the issuance of poor water quality advisories. Moreover, waterfowl (mostly Larus delawarensis and L. argentatus) in nearshore and offshore areas are common and may serve as non-point sources for bacterial contamination of recreational waters. Current beach management practice involves daily mechanical grooming of the nearshore sand for aesthetics and removal of hazardous debris. However, this practice has not been evaluated in terms of its effects on E. coli loading to beach sand and potential introduction to contiguous swimming water. In this study, we tested E. coli responses to three treatments: mechanical groomer, daily and twice weekly hand raking, and a control (no raking/grooming). A randomized block design consisted of replicated treatments and one control (10 each), for a total of 40 blocks sampled daily for 10 days. Foreshore sand samples were collected by hand coring to an average depth of 10 cm. Median E. colirecovered were 73 (mechanically groomed), 27 (hand-raked daily), 32 (hand-raked twice weekly), and 22 (control) colony-forming units (CFU) per gram dry weight sand. E. colicounts in sand that was groomed were significantly higher than hand rakings and control (p <0.0001), and there was no significant difference between control and raking treatments (p<0.01). This study demonstrates the beach management implications related to grooming efficacy and the importance of understanding non-point sources of bacterial contamination.

Food Safety Practices Linked with Proper Refrigerator Temperatures in Retail Delis.

PubMed

Brown, Laura G; Hoover, Edward Rickamer; Faw, Brenda V; Hedeen, Nicole K; Nicholas, David; Wong, Melissa R; Shepherd, Craig; Gallagher, Daniel L; Kause, Janell R

2018-05-01

Listeria monocytogenes (L. monocytogenes) causes the third highest number of foodborne illness deaths annually. L. monocytogenes contamination of sliced deli meats at the retail level is a significant contributing factor to L. monocytogenes illness. The Centers for Disease Control and Prevention's Environmental Health Specialists Network (EHS-Net) conducted a study to learn more about retail delis' practices concerning L. monocytogenes growth and cross-contamination prevention. This article presents data from this study on the frequency with which retail deli refrigerator temperatures exceed 41°F, the Food and Drug Administration (FDA)-recommended maximum temperature for ready-to-eat food requiring time and temperature control for safety (TCS) (such as retail deli meat). This provision was designed to control bacterial growth in TCS foods. This article also presents data on deli and staff characteristics related to the frequency with which retail delis refrigerator temperatures exceed 41°F. Data from observations of 445 refrigerators in 245 delis showed that in 17.1% of delis, at least one refrigerator was >41°F. We also found that refrigeration temperatures reported in this study were lower than those reported in a related 2007 study. Delis with more than one refrigerator, that lacked refrigerator temperature recording, and had a manager who had never been food safety certified had greater odds of having a refrigerator temperature >41°F. The data from this study suggest that retail temperature control is improving over time. They also identify a food safety gap: some delis have refrigerator temperatures that exceed 41°F. We also found that two food safety interventions were related to better refrigerated storage practices: kitchen manager certification and recording refrigerated storage temperatures. Regulatory food safety programs and the retail industry may wish to consider encouraging or requiring kitchen manager certification and recording refrigerated storage temperatures.

Archaeological recording and chemical stratigraphy applied to contaminated land studies.

PubMed

Photos-Jones, Effie; Hall, Allan J

2011-11-15

The method used by archaeologists for excavation and recording of the stratigraphic evidence, within trenches with or without archaeological remains, can potentially be useful to contaminated land consultants (CLCs). The implementation of archaeological practice in contaminated land assessments (CLAs) is not meant to be an exercise in data overkill; neither should it increase costs. Rather, we suggest, that if the excavation and recording, by a trained archaeologist, of the stratigraphy is followed by in-situ chemical characterisation then it is possible that much uncertainty associated with current field sampling practices, may be removed. This is because built into the chemical stratigraphy is the temporal and spatial relationship between different parts of the site reflecting the logic behind the distribution of contamination. An archaeological recording with chemical stratigraphy approach to sampling may possibly provide 'one method fits all' for potentially contaminated land sites (CLSs), just as archaeological characterisation of the stratigraphic record provides 'one method fits all' for all archaeological sites irrespective of period (prehistoric to modern) or type (rural, urban or industrial). We also suggest that there may be practical and financial benefits to be gained by pulling together expertise and resources stemming from different disciplines, not simply at the assessment phase, but also subsequent phases, in contaminated land improvement. Copyright © 2011 Elsevier B.V. All rights reserved.

Assessing the hydrocarbon degrading potential of indigenous bacteria isolated from crude oil tank bottom sludge and hydrocarbon-contaminated soil of Azzawiya oil refinery, Libya.

PubMed

Mansur, Abdulatif A; Adetutu, Eric M; Kadali, Krishna K; Morrison, Paul D; Nurulita, Yuana; Ball, Andrew S

2014-09-01

The disposal of hazardous crude oil tank bottom sludge (COTBS) represents a significant waste management burden for South Mediterranean countries. Currently, the application of biological systems (bioremediation) for the treatment of COTBS is not widely practiced in these countries. Therefore, this study aims to develop the potential for bioremediation in this region through assessment of the abilities of indigenous hydrocarbonoclastic microorganisms from Libyan Hamada COTBS for the biotreatment of Libyan COTBS-contaminated environments. Bacteria were isolated from COTBS, COTBS-contaminated soil, treated COTBS-contaminated soil, and uncontaminated soil using Bushnell Hass medium amended with Hamada crude oil (1 %) as the main carbon source. Overall, 49 bacterial phenotypes were detected, and their individual abilities to degrade Hamada crude and selected COBTS fractions (naphthalene, phenanthrene, eicosane, octadecane and hexane) were evaluated using MT2 Biolog plates. Analyses using average well colour development showed that ~90 % of bacterial isolates were capable of utilizing representative aromatic fractions compared to 51 % utilization of representative aliphatics. Interestingly, more hydrocarbonoclastic isolates were obtained from treated contaminated soils (42.9 %) than from COTBS (26.5 %) or COTBS-contaminated (30.6 %) and control (0 %) soils. Hierarchical cluster analysis (HCA) separated the isolates into two clusters with microorganisms in cluster 2 being 1.7- to 5-fold better at hydrocarbon degradation than those in cluster 1. Cluster 2 isolates belonged to the putative hydrocarbon-degrading genera; Pseudomonas, Bacillus, Arthrobacter and Brevundimonas with 57 % of these isolates being obtained from treated COTBS-contaminated soil. Overall, this study demonstrates that the potential for PAH degradation exists for the bioremediation of Hamada COTBS-contaminated environments in Libya. This represents the first report on the isolation of hydrocarbonoclastic bacteria from Libyan COTBS and COTBS-contaminated soil.

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.

50 CFR 260.104 - Personnel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... abnormal sources of microbiological contamination, shall work in a food plant in any capacity in which... hygenic practices while on duty, to the extent necessary to prevent contamination of food products. (2... precautions to prevent contamination of foods with microorganisms or foreign substances including, but not...

Reliability and Validity of a Questionnaire to Measure Consumer Knowledge regarding Safe Practices to Prevent Microbiological Contamination in Restaurants

ERIC Educational Resources Information Center

Uggioni, Paula Lazzarin; Salay, Elisabette

2013-01-01

Objective: The objective of this study was to develop a validated and reliable questionnaire to measure consumer knowledge regarding safe practices to prevent microbiological contamination in restaurants and commercial kitchens. Methods: Non-probabilistic samples of individuals were interviewed in the city of Campinas, Brazil. Questionnaire items…

Working conditions and public health risks in slaughterhouses in western Kenya.

PubMed

Cook, Elizabeth Anne Jessie; de Glanville, William Anson; Thomas, Lian Francesca; Kariuki, Samuel; Bronsvoort, Barend Mark de Clare; Fèvre, Eric Maurice

2017-01-05

Inadequate facilities and hygiene at slaughterhouses can result in contamination of meat and occupational hazards to workers. The objectives of this study were to assess current conditions in slaughterhouses in western Kenya and the knowledge, and practices of the slaughterhouse workers toward hygiene and sanitation. Between February and October 2012 all consenting slaughterhouses in the study area were recruited. A standardised questionnaire relating to facilities and practices in the slaughterhouse was administered to the foreperson at each site. A second questionnaire was used to capture individual slaughterhouse workers' knowledge, practices and recent health events. A total of 738 slaughterhouse workers from 142 slaughterhouses completed questionnaires. Many slaughterhouses had poor infrastructure, 65% (95% CI 63-67%) had a roof, cement floor and walls, 60% (95% CI 57-62%) had a toilet and 20% (95% CI 18-22%) had hand-washing facilities. The meat inspector visited 90% (95% CI 92-95%) of slaughterhouses but antemortem inspection was practiced at only 7% (95% CI 6-8%). Nine percent (95% CI 7-10%) of slaughterhouses slaughtered sick animals. Only half of workers wore personal protective clothing - 53% (95% CI 51-55%) wore protective coats and 49% (95% CI 46-51%) wore rubber boots. Knowledge of zoonotic disease was low with only 31% (95% CI 29-33%) of workers aware that disease could be transmitted from animals. The current working conditions in slaughterhouses in western Kenya are not in line with the recommendations of the Meat Control Act of Kenya. Current facilities and practices may increase occupational exposure to disease or injury and contaminated meat may enter the consumer market. The findings of this study could enable the development of appropriate interventions to minimise public health risks. Initially, improvements need to be made to facilities and practices to improve worker safety and reduce the risk of food contamination. Simultaneously, training programmes should target workers and inspectors to improve awareness of the risks. In addition, education of health care workers should highlight the increased risks of injury and disease in slaughterhouse workers. Finally, enhanced surveillance, targeting slaughterhouse workers could be used to detect disease outbreaks. This "One Health" approach to disease surveillance is likely to benefit workers, producers and consumers.

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

JOHNSON, A.R.

Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the qualitymore » of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response.« less

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

JOHNSON, A.R.

Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects, and microorganisms such as molds that adversely affect the qualitymore » of the workplace environment). Biological control activities may be either preventive (a priori) or in response to existing contamination spread (a posteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and a priori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, a posteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response.« less

Bioremediation of copper-contaminated soils by bacteria.

PubMed

Cornu, Jean-Yves; Huguenot, David; Jézéquel, Karine; Lollier, Marc; Lebeau, Thierry

2017-02-01

Although copper (Cu) is an essential micronutrient for all living organisms, it can be toxic at low concentrations. Its beneficial effects are therefore only observed for a narrow range of concentrations. Anthropogenic activities such as fungicide spraying and mining have resulted in the Cu contamination of environmental compartments (soil, water and sediment) at levels sometimes exceeding the toxicity threshold. This review focuses on the bioremediation of copper-contaminated soils. The mechanisms by which microorganisms, and in particular bacteria, can mobilize or immobilize Cu in soils are described and the corresponding bioremediation strategies-of varying levels of maturity-are addressed: (i) bioleaching as a process for the ex situ recovery of Cu from Cu-bearing solids, (ii) bioimmobilization to limit the in situ leaching of Cu into groundwater and (iii) bioaugmentation-assisted phytoextraction as an innovative process for in situ enhancement of Cu removal from soil. For each application, the specific conditions required to achieve the desired effect and the practical methods for control of the microbial processes were specified.

Initially unrecognized distribution of a commercially cooked meat product contaminated over several months with Salmonella serotype Infantis.

PubMed

Kohl, K S; Farley, T A

2000-12-01

An outbreak of salmonellosis occurred among 63 wedding participants. The outbreak was investigated through cohort, laboratory, and environmental studies. Consumption of rice-dressing made from a commercially cooked, meat-based, rice-dressing mix was strongly associated with illness. Nineteen patient isolates, six company/grocery store isolates cultured from the rice-dressing mix, and one environmental isolate from a pump in the production line were of an identical outbreak strain of Salmonella Infantis characterized by pulsed-field gel electrophoresis. In the production line, cooked rice-dressing mix tested negative for S. Infantis before and positive after contact with the contaminated pump. The dressing-mix had an estimated 200 colony-forming units of salmonella per gram of product, and > 180,000 pounds were distributed in 9 states for > or = 2 months before contamination was recognized. Food manufacturers should be required to use systematic, hazard analysis critical control point risk management practices for all processed meat products, validated by periodic microbiologic monitoring of the end product.

Interim results of quality-control sampling of surface water for the Upper Colorado River National Water-Quality Assessment Study Unit, water years 1995-96

USGS Publications Warehouse

Spahr, N.E.; Boulger, R.W.

1997-01-01

Quality-control samples provide part of the information needed to estimate the bias and variability that result from sample collection, processing, and analysis. Quality-control samples of surface water collected for the Upper Colorado River National Water-Quality Assessment study unit for water years 1995?96 are presented and analyzed in this report. The types of quality-control samples collected include pre-processing split replicates, concurrent replicates, sequential replicates, post-processing split replicates, and field blanks. Analysis of the pre-processing split replicates, concurrent replicates, sequential replicates, and post-processing split replicates is based on differences between analytical results of the environmental samples and analytical results of the quality-control samples. Results of these comparisons indicate that variability introduced by sample collection, processing, and handling is low and will not affect interpretation of the environmental data. The differences for most water-quality constituents is on the order of plus or minus 1 or 2 lowest rounding units. A lowest rounding unit is equivalent to the magnitude of the least significant figure reported for analytical results. The use of lowest rounding units avoids some of the difficulty in comparing differences between pairs of samples when concentrations span orders of magnitude and provides a measure of the practical significance of the effect of variability. Analysis of field-blank quality-control samples indicates that with the exception of chloride and silica, no systematic contamination of samples is apparent. Chloride contamination probably was the result of incomplete rinsing of the dilute cleaning solution from the outlet ports of the decaport sample splitter. Silica contamination seems to have been introduced by the blank water. Sampling and processing procedures for water year 1997 have been modified as a result of these analyses.

Assessment of contamination and misclassification biases in a randomized controlled trial of a social network peer education intervention to reduce HIV risk behaviors among drug users and risk partners in Philadelphia, PA and Chiang Mai, Thailand.

PubMed

Simmons, Nicole; Donnell, Deborah; Ou, San-San; Celentano, David D; Aramrattana, Apinun; Davis-Vogel, Annet; Metzger, David; Latkin, Carl

2015-10-01

Controlled trials of HIV prevention and care interventions are susceptible to contamination. In a randomized controlled trial of a social network peer education intervention among people who inject drugs and their risk partners in Philadelphia, PA and Chiang Mai, Thailand, we tested a contamination measure based on recall of intervention terms. We assessed the recall of test, negative and positive control terms among intervention and control arm participants and compared the relative odds of recall of test versus negative control terms between study arms. The contamination measures showed good discriminant ability among participants in Chiang Mai. In Philadelphia there was no evidence of contamination and little evidence of diffusion. In Chiang Mai there was strong evidence of diffusion and contamination. Network structure and peer education in Chiang Mai likely led to contamination. Recall of intervention materials can be a useful method to detect contamination in experimental interventions.

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.

Transport of organic contaminants in subsoil horizons and effects of dissolved organic matter related to organic waste recycling practices.

PubMed

Chabauty, Florian; Pot, Valérie; Bourdat-Deschamps, Marjolaine; Bernet, Nathalie; Labat, Christophe; Benoit, Pierre

2016-04-01

Compost amendment on agricultural soil is a current practice to compensate the loss of organic matter. As a consequence, dissolved organic carbon concentration in soil leachates can be increased and potentially modify the transport of other solutes. This study aims to characterize the processes controlling the mobility of dissolved organic matter (DOM) in deep soil layers and their potential impacts on the leaching of organic contaminants (pesticides and pharmaceutical compounds) potentially present in cultivated soils receiving organic waste composts. We sampled undisturbed soil cores in the illuviated horizon (60-90 cm depth) of an Albeluvisol. Percolation experiments were made in presence and absence of DOM with two different pesticides, isoproturon and epoxiconazole, and two pharmaceutical compounds, ibuprofen and sulfamethoxazole. Two types of DOM were extracted from two different soil surface horizons: one sampled in a plot receiving a co-compost of green wastes and sewage sludge applied once every 2 years since 1998 and one sampled in an unamended plot. Results show that DOM behaved as a highly reactive solute, which was continuously generated within the soil columns during flow and increased after flow interruption. DOM significantly increased the mobility of bromide and all pollutants, but the effects differed according the hydrophobic and the ionic character of the molecules. However, no clear effects of the origin of DOM on the mobility of the different contaminants were observed.

Food safety concerns regarding paratuberculosis.

PubMed

Collins, Michael T

2011-11-01

Both ante mortem and post mortem contamination of foods of animal origin commonly occurs. Food manufacturing practices fail to reliably kill Mycobacterium avium subsp. paratuberculosis (MAP) due to its innate resistance to heat and other physical factors. While medical science does not agree on the human health consequences of MAP exposure, this potentially zoonotic pathogen is found in a significant proportion of people with a disease bearing marked similarity to Johne’s disease (ie, Crohn’s disease). Control of MAP infections in farm animals to mitigate the risk of human exposure is one additional reason for on-farm measures to control Johne’s disease.

High-Level Disinfection of Otorhinolaryngology Clinical Instruments: An Evaluation of the Efficacy and Cost-effectiveness of Instrument Storage.

PubMed

Yalamanchi, Pratyusha; Yu, Jason; Chandler, Laura; Mirza, Natasha

2018-01-01

Objectives Despite increasing interest in individual instrument storage, risk of bacterial cross-contamination of otorhinolaryngology clinic instruments has not been assessed. This study is the first to determine the clinical efficacy and cost-effectiveness of standard high-level disinfection and clinic instrument storage. Methods To assess for cross-contamination, surveillance cultures of otorhinolaryngology clinic instruments subject to standard high-level disinfection and storage were obtained at the start and end of the outpatient clinical workday. Rate of microorganism recovery was compared with cultures of instruments stored in individual peel packs and control cultures of contaminated instruments. Based on historical clinic data, the direct allocation method of cost accounting was used to determine aggregate raw material cost and additional labor hours required to process and restock peel-packed instruments. Results Among 150 cultures of standard high-level disinfected and co-located clinic instruments, 3 positive bacterial cultures occurred; 100% of control cultures were positive for bacterial species ( P < .001). There was no statistical difference between surveillance cultures obtained before and after the clinic day. While there was also no significant difference in rate of contamination between peel-packed and co-located instruments, peel packing all instruments requires 6250 additional labor hours, and conservative analyses place the cost of individual semicritical instrument storage at $97,852.50 per year. Discussion With in vitro inoculation of >200 otorhinolaryngology clinic instruments, this study demonstrates that standard high-level disinfection and storage are equally efficacious to more time-consuming and expensive individual instrument storage protocols, such as peel packing, with regard to bacterial contamination. Implications for Practice Standard high-level disinfection and storage are equally effective to labor-intensive and costly individual instrument storage protocols.

Role of Fungicides, Application of Nozzle Types, and the Resistance Level of Wheat Varieties in the Control of Fusarium Head Blight and Deoxynivalenol

PubMed Central

Mesterházy, Ákos; Tóth, Beáta; Varga, Monika; Bartók, Tibor; Szabó-Hevér, Ágnes; Farády, László; Lehoczki-Krsjak, Szabolcs

2011-01-01

Fungicide application is a key factor in the control of mycotoxin contamination in the harvested wheat grain. However, the practical results are often disappointing. In 2000-2004, 2006-2008 and 2007 and 2008, three experiments were made to test the efficacy of fungicide control on Fusarium Head Blight (FHB) in wheat and to find ways to improve control of the disease and toxin contamination. In a testing system we have used for 20 years, tebuconazole and tebuconazole + prothioconazole fungicides regularly reduced symptoms by about 80% with a correlating reduction in toxin contamination. Averages across the years normally show a correlation of r = 0.90 or higher. The stability differences (measured by the stability index) between the poorest and the best fungicides are about 10 or more times, differing slightly in mycotoxin accumulation, FHB index (severity) and Fusarium damaged kernels (FDK). The weak fungicides, like carbendazim, were effective only when no epidemic occurred or epidemic severity was at a very low level. Similar fungicide effects were seen on wheat cultivars which varied in FHB resistance. In this study, we found three fold differences in susceptibility to FHB between highly susceptible and moderately resistant cultivars when treated with fungicides. In the moderately resistant cultivars, about 50% of the fungicide treatments lowered the DON level below the regulatory limit. In the most susceptible cultivars, all fungicides failed to reduce mycotoxin levels low enough for grain acceptance, in spite of the fact that disease was significantly reduced. The results correlated well with the results of the large-scale field tests of fungicide application at the time of natural infection. The Turbo FloodJet nozzle reduced FHB incidence and DON contamination when compared to the TeeJet XR nozzle. Overall, the data suggest that significant decreases in FHB incidence and deoxynivalenol contamination in field situations are possible with proper fungicide applications. Additionally, small plot tests can be used to evaluate the quality of the field disease and toxin production. PMID:22174980

Metrics for Nitrate Contamination of Ground Water at CAFO Land Application Site - Iowa Swine Study

EPA Science Inventory

Nitrate (NO3-) is the most common chemical contaminant found in ground water and there are increasing indications that agriculture contributes to this contamination. In the United States, concentrated animal feeding operations (CAFO) are a common agricultural practice. CAFO lea...

JPL Contamination Control Engineering

NASA Technical Reports Server (NTRS)

Blakkolb, Brian

2013-01-01

JPL has extensive expertise fielding contamination sensitive missions-in house and with our NASA/industry/academic partners.t Development and implementation of performance-driven cleanliness requirements for a wide range missions and payloads - UV-Vis-IR: GALEX, Dawn, Juno, WFPC-II, AIRS, TES, et al - Propulsion, thermal control, robotic sample acquisition systems. Contamination control engineering across the mission life cycle: - System and payload requirements derivation, analysis, and contamination control implementation plans - Hardware Design, Risk trades, Requirements V-V - Assembly, Integration & Test planning and implementation - Launch site operations and launch vehicle/payload integration - Flight ops center dot Personnel on staff have expertise with space materials development and flight experiments. JPL has capabilities and expertise to successfully address contamination issues presented by space and habitable environments. JPL has extensive experience fielding and managing contamination sensitive missions. Excellent working relationship with the aerospace contamination control engineering community/.

Skin and surface lead contamination, hygiene programs, and work practices of bridge surface preparation and painting contractors.

PubMed

Virji, M Abbas; Woskie, Susan R; Pepper, Lewis D

2009-02-01

A 2005 regulatory review of the lead in construction standard by the Occupational Safety and Health Administration (OSHA) noted that alternative pathways of exposure can be as significant as inhalation exposure and that noncompliance with the standard pertaining to hygiene facilities and practices was the second most commonly violated section of the standard. Noncompliance with provisions of the standard and unhealthy work and hygiene practices likely increase the likelihood of take-home lead via contaminated clothing, automobiles, and skin, thus contributing to elevated blood lead levels (BLL) among construction workers and their family members. We performed a cross-sectional study of bridge painters working for small contractors in Massachusetts to investigate causes of persistent elevated BLLs and to assess lead exposures. Thirteen work sites were evaluated for a 2-week period during which surface and skin wipe samples were collected and qualitative information was obtained on personal hygiene practices, decontamination and hand wash facilities, and respiratory protection programs. Results showed lead contamination on workers' skin, respirators, personal automobiles, and the decontamination unit, indicating a significant potential for take-home lead exposure. Overall, the geometric mean (GM) skin lead levels ranged from 373 microg on workers' faces at end of shift to 814 microg on hands at break time. The overall GM lead level inside respirators was 143 microg before work and 286 microg after work. Lead contamination was also present inside workers' personal vehicles as well as on surfaces inside the clean side of the decontamination unit. Review of the respiratory protection programs, work site decontamination and hand wash facilities, and personal hygiene practices indicated that these factors had significant impact on skin and surface contamination levels and identified significant opportunities for improving work site facilities and personal practices. Elevated lead exposure and BLL can be minimized by strict adherence to the OSHA provisions for functioning decontamination and hygiene facilities and healthy personal hygiene practices.

Real and perceived risks for mycotoxin contamination in foods and feeds: challenges for food safety control.

PubMed

Milićević, Dragan R; Skrinjar, Marija; Baltić, Tatjana

2010-04-01

Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption of mycotoxins have occurred for many centuries. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health in general, and induce diverse and powerful toxic effects in test systems: some are carcinogenic, mutagenic, teratogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermotoxic and neurotoxic. Although mycotoxin contamination of agricultural products still occurs in the developed world, the application of modern agricultural practices and the presence of a legislatively regulated food processing and marketing system have greatly reduced mycotoxin exposure in these populations. However, in developing countries, where climatic and crop storage conditions are frequently conducive to fungal growth and mycotoxin production, much of the population relies on subsistence farming or on unregulated local markets. Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot of food commodity and, consequently, of the impact of mycotoxins on human and animal health.

Controlled field evaluation of water flow rate effects on sampling polar organic compounds using polar organic chemical integrative samplers.

PubMed

Li, Hongxia; Vermeirssen, Etiënne L M; Helm, Paul A; Metcalfe, Chris D

2010-11-01

The uptake of polar organic contaminants into polar organic chemical integrative samplers (POCIS) varies with environmental factors, such as water flow rate. To evaluate the influence of water flow rate on the uptake of contaminants into POCIS, flow-controlled field experiments were conducted with POCIS deployed in channel systems through which treated sewage effluent flowed at rates between 2.6 and 37 cm/s. Both pharmaceutical POCIS and pesticide POCIS were exposed to effluent for 21 d and evaluated for uptake of pharmaceuticals and personal care products (PPCPs) and endocrine disrupting substances (EDS). The pesticide POCIS had higher uptake rates for PPCPs and EDS than the pharmaceutical POCIS, but there are some practical advantages to using pharmaceutical POCIS. The uptake of contaminants into POCIS increased with flow rate, but these effects were relatively small (i.e., less than twofold) for most of the test compounds. There was no relationship observed between the hydrophobicity (log octanol/water partition coefficient, log K(OW)) of model compounds and the effects of flow rate on the uptake kinetics by POCIS. These data indicate that water flow rate has a relatively minor influence on the accumulation of PPCPs and EDS into POCIS. © 2010 SETAC.

Contamination control research activities for space optics in JAXA RANDD

NASA Astrophysics Data System (ADS)

Kimoto, Y.

2017-11-01

Contamination control research activities for space optics projects in JAXA R&D are described. More accurate contamination control techniques are requested because of intensified recent science mission requirements. One approach to control the contamination effects is analysis by software. JAXA has been developing a contamination analytical tool "J-SPICE" (Japanese Spacecraft Induced Contamination analysis software) as well as experiment facilities to improve the J-SPICE. A reflection model in J-SPICE has been experimentally verified and outgassing model data has been acquired by a facility. JAXA has developed a facility which could determine the influence of the contamination at a specific wavelength by combining a vacuum chamber with an I-R spectrometer and performed an experiment to inspect the effect of baking. Space material exposure experiment results reveal the actual thickness of the contamination layer in ISS orbit.

U.S. Geological Survey toxic Waste-Groundwater Contamination Program, fiscal year 1985

NASA Astrophysics Data System (ADS)

Ragone, Stephen E.

1986-09-01

In fiscal year 1982, the U S Geological Survey began an interdisciplinary research thrust entitled Toxic Waste-Groundwater Contamination Program The objective of the thrust was to provide earth sciences information necessary to evaluate and mitigate existing groundwater contamination problems resulting from the planned or inadvertant disposal of wastes and from certain land-use practices, and to improve future waste disposal and land-use practices The program supports process-oriented and interdisciplinary field research, and regional groundwater quality studies This article provides an overview of the current (Fiscal Year 1985) activities of the Toxic Waste Program

The challenge of documenting water quality benefits of conservation practices: a review of USDA-ARS's conservation effects assessment project watershed studies.

PubMed

Tomer, M D; Locke, M A

2011-01-01

The Conservation Effects Assessment Project was established to quantify water quality benefits of conservation practices supported by the U.S. Department of Agriculture (USDA). In 2004, watershed assessment studies were begun in fourteen agricultural watersheds with varying cropping systems, landscapes, climate, and water quality concerns. This paper reviews USDA Agricultural Research Service 'Benchmark' watershed studies and the challenge of identifying water quality benefits in watersheds. Study goals included modeling and field research to assess practices, and evaluation of practice placement in watersheds. Not all goals were met within five years but important lessons were learned. While practices improved water quality, problems persisted in larger watersheds. This dissociation between practice-focused and watershed-scale assessments occurred because: (1) Conservation practices were not targeted at critical sources/pathways of contaminants; (2) Sediment in streams originated more from channel and bank erosion than from soil erosion; (3) Timing lags, historical legacies, and shifting climate combined to mask effects of practice implementation; and (4) Water quality management strategies addressed single contaminants with little regard for trade-offs among contaminants. These lessons could help improve conservation strategies and set water quality goals with realistic timelines. Continued research on agricultural water quality could better integrate modeling and monitoring capabilities, and address ecosystem services.

Assessment of contamination and misclassification biases in a randomized controlled trial of a social network peer education intervention to reduce HIV risk behaviors among drug users and risk partners in Philadelphia, PA and Chiang Mai, Thailand

PubMed Central

Simmons, Nicole; Donnell, Deborah; Ou, San-san; Celentano, David D.; Aramrattana, Apinun; Davis-Vogel, Annet; Metzger, David; Latkin, Carl

2015-01-01

Context Controlled trials of educational interventions are susceptible to contamination. Objectives To test a contamination measure based on recall of terms. Main study A randomized controlled trial of a social network peer education intervention among 1,123 injection drug users and risk partners in Philadelphia, PA and Chiang Mai, Thailand. Methods We assessed the recall of test, negative and positive control terms by intervention and control arm participants and compared the relative odds (OR) of recall of test vs. negative control terms between study arms. Results The contamination measure showed good discriminant ability only among participants from Chiang Mai. In Philadelphia there was no evidence of contamination and little evidence of diffusion. In Chiang Mai there was evidence of diffusion and contamination of 4 of 5 terms tested. Conclusions Network structure and peer education in Chiang Mai likely led to contamination. Recall of intervention materials can be a useful method to detect contamination in trials of educational interventions. PMID:25935214

Reduction in Blood Culture Contamination Through Use of Initial Specimen Diversion Device

PubMed Central

Cavalieri, R. Jennifer; Marolf, Cole; Lyden, Elizabeth

2017-01-01

Abstract Background. Blood culture contamination is a clinically significant problem that results in patient harm and excess cost. Methods. In a prospective, controlled trial at an academic center Emergency Department, a device that diverts and sequesters the initial 1.5–2 mL portion of blood (which presumably carries contaminating skin cells and microbes) was tested against standard phlebotomy procedures in patients requiring blood cultures due to clinical suspicion of serious infection. Results. In sum, 971 subjects granted informed consent and were enrolled resulting in 904 nonduplicative subjects with 1808 blood cultures. Blood culture contamination was significantly reduced through use of the initial specimen diversion device™ (ISDD) compared to standard procedure: (2/904 [0.22%] ISDD vs 16/904 [1.78%] standard practice, P = .001). Sensitivity was not compromised: true bacteremia was noted in 65/904 (7.2%) ISDD vs 69/904 (7.6%) standard procedure, P = .41. No needlestick injuries or potential bloodborne pathogen exposures were reported. The monthly rate of blood culture contamination for all nurse-drawn and phlebotomist-drawn blood cultures was modeled using Poisson regression to compare the 12-month intervention period to the 6 month before and after periods. Phlebotomists (used the ISDD) experienced a significant decrease in blood culture contamination while the nurses (did not use the ISDD) did not. In sum, 73% of phlebotomists completed a post-study anonymous survey and widespread user satisfaction was noted. Conclusions. Use of the ISDD was associated with a significant decrease in blood culture contamination in patients undergoing blood cultures in an Emergency Department setting. Clinical Trials Registration. NCT02102087. PMID:28379370

Elimination of high titre HIV from fibreoptic endoscopes.

PubMed Central

Hanson, P J; Gor, D; Jeffries, D J; Collins, J V

1990-01-01

Concern about contamination of fibreoptic endoscopes with human immunodeficiency virus (HIV) has generated a variety of disruptive and possibly unnecessary infection control practices in endoscopy units. Current recommendations on the cleaning and disinfection of endoscopes have been formulated without applied experimental evidence of the effective removal of HIV from endoscopes. To study the kinetics of elimination of HIV from endoscope surfaces, we artificially contaminated the suction-biopsy channels of five Olympus GIF XQ20 endoscopes with high titre HIV in serum. The air and water channels of two instruments were similarly contaminated. Contamination was measured by irrigating channels with viral culture medium and collecting 3 ml at the distal end for antigen immunoassay. Endoscopes were then cleaned manually in neutral detergent according to the manufacturer's recommendations and disinfected in 2% alkaline glutaraldehyde (Cidex, Surgikos) for two, four, and ten minutes. Contamination with HIV antigens was measured before and after cleaning and after each period of disinfection. Initial contamination comprised 4.8 x 10(4) to 3.5 x 10(6) pg HIV antigen/ml. Cleaning in detergent achieved a reduction to 165 pg/ml (99.93%) on one endoscope and to undetectable levels (100%) on four. After two minutes in alkaline glutaraldehyde all samples were negative and remained negative after the longer disinfection times. Air and water channels, where contaminated, were tested after 10 minutes' disinfection and were negative. These findings underline the importance of cleaning in removing HIV from endoscope and indicate that the use of dedicated equipment and long disinfection times are unnecessary. PMID:2379868

THE OCCURRENCE OF CONTAMINANT ACCUMULATION IN LEAD PIPE SCALES FROM DOMESTIC DRINKING WATER DISTRIBUTION SYSTEMS

EPA Science Inventory

Previous work has shown that contaminants, such as Al, As and Ra, can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could result in elevated levels at consumers’ taps, and current monitoring practices d...

ISSUES IN UNDERSTANDING DERMAL EXPOSURES RESULTING FROM CONTACT WITH CONTAMINATED SURFACES, MEASURING SURFACE CONTAMINATION, AND CHARACTERIZING TRANSFERS

EPA Science Inventory

Although monitoring for surface contamination in work with radioactive materials and dermal monitoring of pesticide exposure to agricultural workers have been standard practice for 50 years, regular surface sampling and dermal monitoring methods have only been applied to indust...

Contamination Control in Hybrid Microelectronic Modules. Part 1: Identification of Critical Process and Contaminants

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Various hybrid processing steps, handling procedures, and materials are examined in an attempt to identify sources of contamination and to propose methods for the control of these contaminants. It is found that package sealing, assembly, and rework are especially susceptible to contamination. Moisture and loose particles are identified as the worst contaminants. The points at which contaminants are most likely to enter the hybrid package are also identified, and both general and specific methods for their detection and control are developed. In general, the most effective controls for contaminants are: clean working areas, visual inspection at each step of the process, and effective cleaning at critical process steps. Specific methods suggested include the detection of loose particles by a precap visual inspection, by preseal and post-seal electrical testing, and by a particle impact noise test. Moisture is best controlled by sealing all packages in a clean, dry, inert atmosphere after a thorough bake-out of all parts.

The Challenges and Solutions for Cadmium-contaminated Rice in China: A Critical Review.

PubMed

Hu, Yuanan; Cheng, Hefa; Tao, Shu

2016-01-01

The wide occurrence of Cd-contaminated rice in southern China poses significant public health risk and deserves immediate action, which arises primarily from extensive metal (including Cd) contamination of paddies with the fast expansion of nonferrous metal mining and smelting activities. Accumulation of Cd in rice grains can be reduced by removing Cd from the contaminated paddy soils, reducing its bioavailability, and controlling its uptake by rice plants. Although a range of measures can be taken to rehabilitate Cd-contaminated lands, including soil replacement and turnover, chemical washing, and phytoremediation, they are either too expensive and/or too slow. Various amendment materials, including lime, animal manures, and biochar, can be used to immobilize Cd in soils, but such fixation approach can only temporarily reduce Cd availability to rice uptake. Cultivation of alternative crops with low Cd accumulation in edible plant parts is impractical on large scales due to extensive contamination and food security concerns in southern China. Transgenic techniques can help develop rice cultivars with low Cd accumulation in grains, but little public acceptance is expected for such products. As an alternative, selection and development of low-Cd rice varieties and hybrids through plant biotechnology and breeding, particularly, by integration of marker-assisted selection (MAS) with traditional breeding, could be a practical and acceptable option that would allow continued rice production in soils with high bioavailability of Cd. Plant biotechnology and breeding can also help develop Cd-hyperaccumulating rice varieties, which can greatly facilitate phytoremediation of contaminated paddies. To eliminate the long-term risk of Cd entering the food chain, soils contaminated by Cd should be cleaned up when cost-effective remediation measures are available. Copyright © 2016 Elsevier Ltd. All rights reserved.

Water quality concerns due to forest fires: polycyclic aromatic hydrocarbons (PAH) contamination of groundwater from mountain areas.

PubMed

Mansilha, C; Carvalho, A; Guimarães, P; Espinha Marques, J

2014-01-01

Water quality alterations due to forest fires may considerably affect aquatic organisms and water resources. These impacts are cumulative as a result of pollutants mobilized from fires, chemicals used to fight fire, and postfire responses. Few studies have examined postfire transport into water resources of trace elements, including the polycyclic aromatic hydrocarbons (PAH), which are organic pollutants produced during combustion and are considered carcinogenic and harmful to humans. PAH are also known to adversely affect survival, growth, and reproduction of many aquatic species. This study assessed the effects of forest wildfires on groundwater from two mountain regions located in protected areas from north and central Portugal. Two campaigns to collect water samples were performed in order to measure PAH levels. Fifteen of 16 studied PAH were found in groundwater samples collected at burned areas, most of them at concentrations significantly higher than those found in control regions, indicating aquifer contamination. The total sum of PAH in burned areas ranged from 23.1to 95.1 ng/L with a median of 62.9 ng/L, which is one- to sixfold higher than the average level measured in controls (16.2 ng/L). In addition, in control samples, the levels of light PAH with two to four rings were at higher levels than heavy PAH with five or six rings, thus showing a different profile between control and burned sites. The contribution of wildfires to groundwater contamination by PAH was demonstrated, enabling a reliable assessment of the impacts on water quality and preparation of scientifically based decision criteria for postfire forest management practices.

Dairy farms testing positive for Mycobacterium avium ssp. paratuberculosis have poorer hygiene practices and are less cautious when purchasing cattle than test-negative herds.

PubMed

Wolf, R; Barkema, H W; De Buck, J; Orsel, K

2016-06-01

Mycobacterium avium ssp. paratuberculosis (MAP), the causative agent of Johne's disease, is present on most dairy farms in Alberta, causing economic losses and presenting a potential public health concern. The objective of this cross-sectional study was to identify risk factors for Alberta dairy herds being MAP-positive based on environmental samples (ES). Risk assessments were conducted and ES were collected on 354 Alberta dairy farms (62% of eligible producers) voluntarily participating in the Alberta Johne's Disease Initiative. In univariate logistic regression, risk factors addressing animal and pen hygiene, as well as the use of feeding equipment to remove manure and manure application on pastures, were all associated with the number of positive ES. Furthermore, based on factor analysis, risk factors were clustered and could be summarized as 4 independent factors: (1) animal, pen, and feeder contamination; (2) shared equipment and pasture contamination; (3) calf diet; and (4) cattle purchase. Using these factor scores as independent variables in multivariate logistic regression models, a 1-unit increase in animal, pen, and feeder contamination resulted in 1.31 times higher odds of having at least 1 positive ES. Furthermore, a 1-unit increase in cattle purchase also resulted in 1.31 times the odds of having at least 1 positive ES. Finally, a 100-cow increase in herd size resulted in an odds ratio of 2.1 for having at least 1 positive ES. In conclusion, cleanliness of animals, pens, and feeders, as well as cattle purchase practices, affected risk of herd infection with MAP. Therefore, improvements in those management practices should be the focus of effective tools to control MAP on dairy farms. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evaluating the Sensitivity of a Media-Fill Challenge Test Under Various Situations as a Reliable Method for Recommended Aseptic Technique Competency Assessment

PubMed Central

Moody, Colleen A.; Eckel, Stephen F.; Amerine, Lindsey B.

2015-01-01

Background: Microbial contamination of compounded medications is a serious concern within hospital pharmacies as it can lead to severe patient injury. The United States Pharmacopeia <797> mandates that pharmacy personnel responsible for preparing compounded sterile preparations must annually demonstrate competency in aseptic technique by performing a media-fill challenge test. Objective: The purpose of this study is to evaluate the sensitivity of a commonly used media-fill test through proper and improper compounding techniques. Methods: Two aseptically trained pharmacy technicians performed media-fill challenge testing by carrying out 5 separate manipulations 5 times each for a total of 25 trials. Sterile vials, syringes, and intravenous bags were prepared. The first manipulation followed best-practice aseptic technique and sterile compounding procedures. Each of the following 4 manipulations removed one aspect of best-practice aseptic technique. The prepared products were incubated at 20°C to 25°C. A positive result for microbial contamination is indicated by visible turbidity within the vials, syringes, and intravenous bags at the following check points: 24 hours, 72 hours, 7 days, 14 days, 21 days, and >30 days. Results: Twenty-five trials, each containing 10 distinct admixtures, resulted in a total of 250 compounded preparations. No single preparation showed signs of turbidity, sedimentation, or visible microbial growth at any of the 6 checkpoints yielding a 0% contamination rate. However, the positive controls inoculated with bacteria did have positive microbial growth results. Conclusion: A more sensitive test needs to be developed to provide assurances that all poor aseptic practices are detected in compounding personnel.

Contamination control in hybrid microelectronic modules. Identification of critical process and contaminants, part 1

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Hybrid processes, handling procedures, and materials were examined to identify the critical process steps in which contamination is most likely to occur, to identify the particular contaminants associated with these critical steps, and to propose method for the control of these contaminants.

Bacterial contamination of ex vivo processed PBPC products under clean room conditions.

PubMed

Ritter, Markus; Schwedler, Joachim; Beyer, Jörg; Movassaghi, Kamran; Mutters, Reinier; Neubauer, Andreas; Schwella, Nimrod

2003-11-01

Patients undergoing high-dose radio- and/or chemotherapy and autologous or allogeneic PBPC transplantation are at high risk for infections owing to profound immunosuppression. In this study, the rate of microbial contamination of ex vivo processed PBPC products was analyzed, comparing preparation under clean room conditions to standard laboratory conditions. After implementation of good manufacturing practice conditions in the two participating institutions, the microbial contamination rate of 366 PBPC harvests from 198 patients was determined under certified clean room conditions (Group A) from 2000 until 2002. To investigate influence of improved environmental conditions along with other parameters, this set of samples was compared with a historical control set of 1413 PBPC products, which have been processed ex vivo under a clean bench in a regular laboratory room and were harvested from 626 patients (Group B) from 1989 until 2000. In Group B microbial contamination was found in 74 PBPC products (5.2%) from 57 patients. In Group A microbial growth was detected in 3 leukapheresis products (0.8%) from 3 patients. After exclusion of PBPC products, which were probably contaminated before manipulation, statistical analysis showed a significant difference (chi2= 10.339; p < 0.001). These data suggest an impact of clean room conditions on the bacterial contamination rate of PBPC products. To identify confounding variables, variables like technique of leukapheresis, culture methodology, and microbial colonization of central venous catheters were taken into account. Further variables might be identified in following studies.

Retail Deli Slicer Inspection Practices: An EHS-Net Study.

PubMed

Lipcsei, Lauren E; Brown, Laura G; Hoover, E Rickamer; Faw, Brenda V; Hedeen, Nicole; Matis, Bailey; Nicholas, David; Ripley, Danny

2018-05-01

The Centers for Disease Control and Prevention (CDC) estimates that 3,000 people die in the United States each year from foodborne illness, and Listeria monocytogenes causes the third highest number of deaths. Risk assessment data indicate that L. monocytogenes contamination of particularly delicatessen meats sliced at retail is a significant contributor to human listeriosis. Mechanical deli slicers are a major source of L. monocytogenes cross-contamination and growth. In an attempt to prevent pathogen cross-contamination and growth, the U.S. Food and Drug Administration (FDA) created guidance to promote good slicer cleaning and inspection practices. The CDC's Environmental Health Specialists Network conducted a study to learn more about retail deli practices concerning these prevention strategies. The present article includes data from this study on the frequency with which retail delis met the FDA recommendation that slicers should be inspected each time they are properly cleaned (defined as disassembling, cleaning, and sanitizing the slicer every 4 h). Data from food worker interviews in 197 randomly selected delis indicate that only 26.9% of workers ( n = 53) cleaned and inspected their slicers at this frequency. Chain delis and delis that serve more than 300 customers on their busiest day were more likely to have properly cleaned and inspected slicers. Data also were collected on the frequency with which delis met the FDA Food Code provision that slicers should be undamaged. Data from observations of 685 slicers in 298 delis indicate that only 37.9% of delis ( n = 113) had slicers that were undamaged. Chain delis and delis that provide worker training were more likely to have slicers with no damage. To improve slicer practices, food safety programs and the retail food industry may wish to focus on worker training and to focus interventions on independent and smaller delis, given that these delis were less likely to properly inspect their slicers and to have undamaged slicers.

Evaluation of Nonpoint-Source Contamination, Wisconsin: Selected Topics for Water Year 1995

USGS Publications Warehouse

Owens, D.W.; Corsi, Steven R.; Rappold, K.F.

1997-01-01

The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMP's) for controlling nonpoint-source contamination in eight rural and four urban watersheds. This report, the fourth in an annual series of reports, presents a summary of the data collected for the program by the U.S. Geological Survey and the results of several detailed analyses of the data. To complement assessments of water quality, a land-use and BMP inventory is ongoing for 12 evaluation monitoring projects to track nonpoint sources of contamination in each watershed and to document implementation of BMP's that were designed to cause changes in the water quality of streams. Each year, updated information is gathered, mapped, and stored in a geographic-information-system data base. Summaries of land-use, BMP implementation, and water-quality data collected during water years 1989-95 are presented. Storm loads, snowmelt-period loads, and annual loads of suspended sediment and total phosphorus are summarized for eight rural sites. Storm-load data for suspended solids, total phosphorus, total recoverable lead, copper, zinc, and cadmium are summarized for four urban sites. Quality-assurance and quality-control (QA/QC) samples were collected at the eight rural sites to evaluate inorganic sample contamination and at one urban site to evaluate sample-collection and filtration techniques for polycyclic aromatic hydrocarbons (PAR's). Some suspended solids and fecal coliform contamination was detected at the rural sites. Corrective actions will be taken to address this contamination. Evaluation of PAR sample-collection techniques did not uncover any deficiencies, but the small amount of data collected was not sufficient to draw any definite conclusions. Evaluation of PAR filtration techniques indicate that water-sample filtration with O.7-um glass-fiber filters in an aluminum filter unit does not result in significant loss of PAR.

Predicting and preventing mold spoilage of food products.

PubMed

Dagnas, Stéphane; Membré, Jeanne-Marie

2013-03-01

This article is a review of how to quantify mold spoilage and consequently shelf life of a food product. Mold spoilage results from having a product contaminated with fungal spores that germinate and form a visible mycelium before the end of the shelf life. The spoilage can be then expressed as the combination of the probability of having a product contaminated and the probability of mold growth (germination and proliferation) up to a visible mycelium before the end of the shelf life. For products packed before being distributed to the retailers, the probability of having a product contaminated is a function of factors strictly linked to the factory design, process, and environment. The in-factory fungal contamination of a product might be controlled by good manufacturing hygiene practices and reduced by particular processing practices such as an adequate air-renewal system. To determine the probability of mold growth, both germination and mycelium proliferation can be mathematically described by primary models. When mold contamination on the product is scarce, the spores are spread on the product and more than a few spores are unlikely to be found at the same spot. In such a case, models applicable for a single spore should be used. Secondary models can be used to describe the effect of intrinsic and extrinsic factors on either the germination or proliferation of molds. Several polynomial models and gamma-type models quantifying the effect of water activity and temperature on mold growth are available. To a lesser extent, the effect of pH, ethanol, heat treatment, addition of preservatives, and modified atmospheres on mold growth also have been quantified. However, mold species variability has not yet been properly addressed, and only a few secondary models have been validated for food products. Once the probability of having mold spoilage is calculated for various shelf lives and product formulations, the model can be implemented as part of a risk management decision tool.

International Space Station External Contamination Status

NASA Technical Reports Server (NTRS)

Mikatarian, Ron; Soares, Carlos

2000-01-01

PResentation slides examine external contamination requirements; International Space Station (ISS) external contamination sources; ISS external contamination sensitive surfaces; external contamination control; external contamination control for pre-launch verification; flight experiments and observations; the Space Shuttle Orbiter waste water dump, materials outgassing, active vacuum vents; example of molecular column density profile, modeling and analysis tools; sources of outgassing induced contamination analyzed to date, quiescent sources, observations on optical degradation due to induced external contamination in LEO; examples of typical contaminant and depth profiles; and status of the ISS system, material outgassing, thruster plumes, and optical degradation.

Engineering hyporheic zones for the attenuation of urban pesticides and other stormwater trace organic contaminants

NASA Astrophysics Data System (ADS)

Portmann, A. C.; Halpin, B. N.; Herzog, S.; Higgins, C.; McCray, J. E.

2017-12-01

The hyporheic zone (HZ) is a natural bioreactor that can provide in-stream attenuation of various nonpoint source contaminants. Main contributions of nonpoint source pollution are coming from urban stormwater and agricultural runoff, which both adversely impact aquatic life. Stormwater pollutants of concern commonly include nutrients, metals, pathogens, and trace organic contaminants (TOrCs). Despite substantial water quality challenges, current stormwater management typically focuses on water quantity issues rather than pollutant removal. Furthermore, current HZ restoration best management practices do not explicitly control HZ residence times, and generally only induce localized effects. To increase hyporheic exchange and therefore improving water quality, we introduced engineered streambeds featuring modifications to subsurface hydraulic conductivity (K) and reactivity - termed Biohydrochemical Enhancements for Streamwater Treatment (BEST). BEST modifications comprise subsurface modules that employ 1) low-permeability sediments to drive hyporheic exchange and control subsurface residence times, and 2) permeable reactive geomedia to change reaction rates within the HZ. Here we present performance data collected in constructed stream experiments, comparing an all-sand control condition with a stream containing BEST modules and a mixture of 70/30 sand/woodchips (v/v). We evaluated the attenuation of a suite of TOrCs in the BEST versus the control system for two different streambed media: a coarse sand with K = 0.48 cm/s and a fine sand with K = 0.16 cm/s. The range of TOrCs investigated comprises urban pesticides and other stormwater relevant TOrCs. Benefits of applying BEST include increased exchange between streamwater and HZ water, leading to diverse redox conditions that are beneficial for aquatic organisms and will facilitate in-stream pollutant transformation. Future work will focus on tailoring the BEST design for specific pollutants, thereby controlling HZ residence times to match reaction timescales and conditions of interest.

Quantitative contamination assessment of Escherichia coli in baby spinach primary production in Spain: Effects of weather conditions and agricultural practices.

PubMed

Allende, Ana; Castro-Ibáñez, Irene; Lindqvist, Roland; Gil, María Isabel; Uyttendaele, Mieke; Jacxsens, Liesbeth

2017-09-18

A quantitative microbial contamination model of Escherichia coli during primary production of baby spinach was developed. The model included only systematic contamination routes (e.g. soil and irrigation water) and it was used to evaluate the potential impact of weather conditions, agricultural practices as well as bacterial fitness in soil on the E. coli levels present in the crop at harvest. The model can be used to estimate E. coli contamination of baby spinach via irrigation water, via soil splashing due to irrigation water or rain events, and also including the inactivation of E. coli on plants due to solar radiation during a variable time of culturing before harvest. Seasonality, solar radiation and rainfall were predicted to have an important impact on the E. coli contamination. Winter conditions increased E. coli prevalence and levels when compared to spring conditions. As regards agricultural practices, both water quality and irrigation system slightly influenced E. coli levels on baby spinach. The good microbiological quality of the irrigation water (average E. coli counts in positive water samples below 1 log/100mL) could have influenced the differences observed among the tested agricultural practices (water treatment and irrigation system). This quantitative microbial contamination model represents a preliminary framework that assesses the potential impact of different factors and intervention strategies affecting E. coli concentrations at field level. Taking into account that E. coli strains may serve as a surrogate organism for enteric bacterial pathogens, obtained results on E. coli levels on baby spinach may be indicative of the potential behaviour of these pathogens under defined conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Internal contamination in the space station

NASA Technical Reports Server (NTRS)

Poythress, C.

1985-01-01

Atmosphere trace contaminant control systems used in the past (Lunar Module and Skylab) and present (nuclear submarines and Shuttle) are discussed. Recommendations are made for the future Space Station contaminant control system. The prevention and control methods used are judicious material selection, detection, and specific removal equipment. Sources and effects of contamination relating to crew and equipment are also discussed.

[Hygiene practices and contamination risks of surface waters by schistosome eggs: the case of an infested village in Northern Senegal].

PubMed

Sow, S; de Vlas, S J; Polman, K; Gryseels, B

2004-02-01

The transmission of intestinal schistosomiasis presumes that faecal materials containing viable schistosome eggs reach natural water bodies infested with snail intermediate host. So far there is little knowledge about the contamination dynamics of streams with schistosome eggs. We conducted a pilot study on defecating behaviour and hygienic practices in an Schistosoma mansoni endemic focus in Northern Senegal. Questionnaires were used to obtain quantitative data on hygienic practices and the use of latrines in 59 children. Although the community was well endowed with pit latrines, most of the children declared that they usually defecated somewhere else, in particular near the streams where the vegetation offers hideouts. Observations based on mapping of defecation sites showed that a considerable number of stools were left just a few meters from the riverbank, thus bearing a high risk of being washed off into the water. All these practices can easily lead to contamination of water bodies with schistosomae eggs. In order to improve hygienic practices and reduce fecal pollution of the environment, a health education model respecting local beliefs and customs would be indispensable.

Zero-tolerance for faecal contamination of carcasses as a tool in the control of O157 VTEC infections.

PubMed

Heuvelink, A E; Roessink, G L; Bosboom, K; de Boer, E

2001-05-21

The Dutch government, the meat producers organisation and the meat industry have recognised O157 VTEC as an important public health hazard, and agreed on the necessity to improve the hygiene in Dutch cattle- and calf-slaughtering establishments. This paper reports activities within a national action programme to achieve this objective, "Zero-tolerance for faecal contamination during slaughter of cattle and calves". The study included inspection of hygienic performances in slaughterhouses, and visual and microbiological (aerobic plate counts, Enterobacteriaceae counts and O157 VTEC presence/absence on visually clean cattle and calf carcasses) assessment of carcass cleanliness. Initial studies concluded that the hygienic performances in the Dutch cattle and calf slaughterhouses should be immediately improved. In 52% of the slaughterhouses inspected, carcasses were observed to be contaminated with hide, hair or faeces. Around 45% of the slaughterhouses had constructural deficiencies likely to lead to structural cross-contamination of carcasses, by direct carcass-carcass contact, or by indirect contacts with floors, walls or steps. In 39% of the slaughterhouses, cleaning and disinfection procedures were inadequate. Visual inspection of chilled carcasses found that in 11 of the 27 slaughterhouses visited, more than 10% of the carcasses were visibly contaminated. In 6 of the 27 slaughterhouses visited, more than 50% of the carcasses inspected were visibly contaminated. Microbiological analysis of visually clean carcasses noted contamination levels similar to those reported from other countries. O157 VTEC were not isolated during this study. Circulation of these findings lead to increased efforts by all parties to fulfil the requirements of the statutory "Zero-tolerance" programme. A follow-up study noted a significant decrease in the proportions of faecally contaminated carcasses, i.e., 7% of chilled carcasses were visibly contaminated with faeces, as opposed to 22% contamination during the initial study. The follow-up study also noted a greater awareness of the importance of good hygienic practices among slaughterhouse personnel and government meat inspectors.

Development of a preprototype trace contaminant control system. [for space stations

NASA Technical Reports Server (NTRS)

1977-01-01

The steady state contaminant load model based on shuttle equipment and material test programs, and on the current space station studies was revised. An emergency upset contaminant load model based on anticipated emergency upsets that could occur in an operational space station was defined. Control methods for the contaminants generated by the emergency upsets were established by test. Preliminary designs of both steady state and emergency contaminant control systems for the space station application are presented.

Using Coupled Energy, Airflow and IAQ Software (TRNSYS/CONTAM) to Evaluate Building Ventilation Strategies.

PubMed

Dols, W Stuart; Emmerich, Steven J; Polidoro, Brian J

2016-03-01

Building energy analysis tools are available in many forms that provide the ability to address a broad spectrum of energy-related issues in various combinations. Often these tools operate in isolation from one another, making it difficult to evaluate the interactions between related phenomena and interacting systems, forcing oversimplified assumptions to be made about various phenomena that could otherwise be addressed directly with another tool. One example of such interdependence is the interaction between heat transfer, inter-zone airflow and indoor contaminant transport. In order to better address these interdependencies, the National Institute of Standards and Technology (NIST) has developed an updated version of the multi-zone airflow and contaminant transport modelling tool, CONTAM, along with a set of utilities to enable coupling of the full CONTAM model with the TRNSYS simulation tool in a more seamless manner and with additional capabilities that were previously not available. This paper provides an overview of these new capabilities and applies them to simulating a medium-size office building. These simulations address the interaction between whole-building energy, airflow and contaminant transport in evaluating various ventilation strategies including natural and demand-controlled ventilation. CONTAM has been in practical use for many years allowing building designers, as well as IAQ and ventilation system analysts, to simulate the complex interactions between building physical layout and HVAC system configuration in determining building airflow and contaminant transport. It has been widely used to design and analyse smoke management systems and evaluate building performance in response to chemical, biological and radiological events. While CONTAM has been used to address design and performance of buildings implementing energy conserving ventilation systems, e.g., natural and hybrid, this new coupled simulation capability will enable users to apply the tool to couple CONTAM with existing energy analysis software to address the interaction between indoor air quality considerations and energy conservation measures in building design and analysis. This paper presents two practical case studies using the coupled modelling tool to evaluate IAQ performance of a CO 2 -based demand-controlled ventilation system under different levels of building envelope airtightness and the design and analysis of a natural ventilation system.

The use of powdered gloves in dental practice: a cause for concern?

PubMed

Field, E A

1997-01-01

To critically review the potential hazards associated with the use of powdered, natural rubber latex (NRL) gloves in dental practice and to report some practical difficulties which may be encountered when handling dental materials with powdered NRL gloves. Articles published in the international literature over the last 10 years. A number of recent studies in the medical and surgical literature have confirmed that NRL proteins leach out of latex gloves and bind to surgical glove powders. The most serious, potential hazard associated with the continued use of powdered NRL gloves in dental practice is that of latex sensitization by exposure to aerosolized NRL proteins. Hand dermatitis is now recognized as an occupational hazard in dentistry and has been associated with the continuous wearing of protective gloves. Studies, in the dermatological literature, have suggested that glove powders may exacerbate an irritant dermatitis and enhance the potential for adverse reactions to other components of NRL gloves. The surgical literature has already highlighted the risks of post-operative granuloma formation, due to glove powder contamination of the surgical wound. The possible effects of powder contamination of dental implant sites, on the outcome and success of implants has yet to be established. Recent in vitro studies have investigated the effect of latex glove contamination on the shear-bond strength of porcelain laminate veneers: one study demonstrated that starch powder significantly affected the bond strength, whereas the other showed that latex glove contamination of the porcelain surface did not have any significant effect. Long-term, in vivo studies are now required. Dental practitioners should consider the potential health risks which are associated with the use of powdered NRL in dental practice. Powder contamination may affect the long-term results and success of clinical procedures in dentistry.

Demonstration of an In-Situ Friction-Sound Probe for Mapping Particle Size at Contaminated Sediment Sites

DTIC Science & Technology

2013-09-01

management practices resulting in the release of contaminants to soil , sediment, and groundwater in coastal environments. At contaminated sediment sites it...the release of contaminants to soil , sediment, and groundwater in coastal environments. Areas of potential concern at these sites are identified by...study will acquire additional soil and groundwater data necessary to satisfactorily evaluate remedial technologies and develop cleanup goals supporting

Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens.

PubMed

Heiger-Bernays, W; Fraser, A; Burns, V; Diskin, K; Pierotti, D; Merchant-Borna, K; McClean, M; Brabander, D; Hynes, H P

2009-01-01

Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil.

Leaching of glyphosate and AMPA under two soil management practices in Burgundy vineyards (Vosne-Romanée, 21-France).

PubMed

Landry, David; Dousset, Sylvie; Fournier, Jean-Claude; Andreux, Francis

2005-11-01

Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for 1 year. The soil was managed under two vineyard soil practices: a chemically treated bare calcosol, and a vegetated calcosol. After 680 mm of rainfall, the vegetated calcosol leachates contained lower amounts of glyphosate and AMPA (0.02% and 0.03%, respectively) than the bare calcosol leachates (0.06% and 0.15%, respectively). No glyphosate and only low amounts of AMPA (<0.01%) were extracted from the soil. Glyphosate, and to a greater extent, AMPA, leach through the soils; thus, both molecules may be potential contaminants of groundwater. However, the alternative soil management practice of grass cover could reduce groundwater contamination by the pesticide.

Perceived Benefits of Participation and Risks of Soil Contamination in St. Louis Urban Community Gardens.

PubMed

Wong, Roger; Gable, Leah; Rivera-Núñez, Zorimar

2018-06-01

Community gardens are credited for promoting health within neighborhoods, by increasing healthy food intake and exercise frequency. These benefits, however, are potentially undermined as urban soils are often contaminated from industrial legacies. The purpose of this study was to examine the perceived benefits of participation and risks of soil contamination within urban community gardens, and factors associated with soil contamination concerns. Ninety-three gardeners were interviewed across 20 community gardens in St. Louis, Missouri between June and August 2015. Surveys included questions on demographics, gardening practices, and perceptions of community gardening. Multilevel logistic models assessed how gardener demographics, gardening practices, and garden characteristics were associated with soil contamination concerns. Common perceived benefits of community gardening were community building (68.8%), healthy and fresh food (35.5%), and gardening education (18.3%). Most gardeners (62.4%) were not concerned about soil contamination, but nearly half (48.4%) stated concerns about heavy metals. Black race was significantly associated with soil contamination concerns (OR 5.47, 95% CI 1.00-30.15, p = .04). Community gardens offer numerous social and health benefits. Although most gardeners were not concerned about soil contamination, black gardeners were more likely to have concerns. Garden leaders should provide resources to gardeners to learn about soil contamination and methods to manage their risk, particularly in minority neighborhoods.

10 CFR 850.31 - Release criteria.

Code of Federal Regulations, 2010 CFR

2010-01-01

... lowest contamination level practicable, but not to exceed the levels established in paragraphs (b) and (c... contamination level of equipment or item surfaces does not exceed the higher of 0.2 µg/100 cm 2 or the... the equipment or item and its future use and the nature of the beryllium contamination. (c) Before...

Plan for the control of Legionella infections in long-term care facilities: role of environmental monitoring.

PubMed

Cristino, Sandra; Legnani, Pier Paolo; Leoni, Erica

2012-04-01

In accordance with the international and national guidelines, the Emilia-Romagna Region (Italy) has established regional guidelines for the surveillance and prevention of legionellosis based on the concept of risk assessment, with particular attention to environmental monitoring. The aim of this study was to verify how environmental surveillance in the context of risk assessment plans could help to guide decisions about preventive strategies against Legionella infections in Long Term Care Facilities (LTCF). In six LTCFs in the city of Bologna (Emilia-Romagna Region) a self-control plan was implemented that included the environmental monitoring of Legionella spp. and the surveillance of hospital-acquired Legionnaires' Disease. At baseline, four hot water systems were colonized by Legionella pneumophila (3 LCTFs) and Legionella londiniensis (1 LCTF). In each establishment specific control measures were adopted based on the characteristics of the system, the virulence of the strain and the level of the contamination. The monitoring, carried out for around two years, was also extended to the ways in which the system and the distal water distribution points were used and maintained with respect to the good practices in operation and management. The adopted actions (shock and/or continuous disinfection treatments) and the implementation of the good practice measures reduced the contamination to acceptable and stable levels. No cases of hospital-acquired legionellosis occurred during the period of study. The environmental surveillance was successful in evaluating the risk and identifying the most suitable preventive strategies. Copyright © 2011 Elsevier GmbH. All rights reserved.

Development of a sorber trace contaminant control system including pre- and post-sorbers for a catalytic oxidizer

NASA Technical Reports Server (NTRS)

Olcott, T. M.

1972-01-01

A general methodology was developed for spacecraft contaminant control system design. Elements considered for contaminant control were catalytic oxidation with isotope or electrical heat and pre- and post-sorbers, charcoal with regeneration and non-regeneration, and reactive constituents. A technique is described for sizing a charcoal bed for a multiple contaminant load.

U.S. Geological Survey toxic Waste-Groundwater Contamination Program, fiscal year 1985

USGS Publications Warehouse

Ragone, S.E.

1986-01-01

In fiscal year 1982, the U S Geological Survey began an interdisciplinary research thrust entitled Toxic Waste-Groundwater Contamination Program The objective of the thrust was to provide earth sciences information necessary to evaluate and mitigate existing groundwater contamination problems resulting from the planned or inadvertant disposal of wastes and from certain land-use practices, and to improve future waste disposal and land-use practices The program supports process-oriented and interdisciplinary field research, and regional groundwater quality studies This article provides an overview of the current (Fiscal Year 1985) activities of the Toxic Waste Program ?? 1986 Springer-Verlag New York Inc.

Microbial populations in contaminant plumes

USGS Publications Warehouse

Haack, S.K.; Bekins, B.A.

2000-01-01

Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation.

Requirements and Sizing Investigation for Constellation Space Suit Portable Life Support System Trace Contaminant Control

NASA Technical Reports Server (NTRS)

Paul, Heather L.; Jennings, Mallory A.; Waguespack, Glenn

2010-01-01

The Trace Contaminant Control System (TCCS), located within the ventilation loop of the Constellation Space Suit Portable Life Support System (PLSS), is responsible for removing hazardous trace contaminants from the space suit ventilation flow. This paper summarizes the results of a trade study that evaluated if trace contaminant control could be accomplished without a TCCS, relying on suit leakage, ullage loss from the carbon dioxide and humidity control system, and other factors. Trace contaminant generation rates were revisited to verify that values reflect the latest designs for Constellation Space Suit System (CSSS) pressure garment materials and PLSS hardware. Additionally, TCCS sizing calculations were performed and a literature survey was conducted to review the latest developments in trace contaminant technologies.

Meat Safety: An Evaluation of Portuguese Butcher Shops.

PubMed

Santos, Ana; Cardoso, Margarida Fonseca; Costa, José M Correia da; Gomes-Neves, Eduarda

2017-07-01

Butcher shops are end points in the meat chain, and they can have a determinant role in cross-contamination control. This study aims to determine whether Portuguese butcher shops comply with European and Portuguese law regarding the sale of fresh meat and meat products. Butcher shops (n = 73) were assessed for meat handler and facility hygiene and for maintenance of the premises. Handlers (n = 88) were given a questionnaire composed of questions about knowledge and practice, including hazard analysis and critical control point (HACCP) and good practice in food industry, to assess their knowledge of and compliance with food safety practices. A checklist of 27 items was used to evaluate facility and meat handler hygiene and butcher shop maintenance. Our results revealed some lack of compliance in all the areas evaluated. The mean knowledge and practice score among the operators was 68.0%, and the mean "visual inspection" score for the butcher shops was 64.0%. Severe deficiencies were observed in the mandatory implementation of HACCP principles in this type of small food business. These findings indicate a need to modify training to enhance compliance with European food safety regulations at this step of the meat chain.

Applications of aerospace technology in industry, a technology transfer profile: Contamination control

NASA Technical Reports Server (NTRS)

1971-01-01

The strong influence NASA-sponsored research has had on the development of solutions to difficult contamination problems is considered. The contamination control field is comprised of an industrial base, supplying the tools of control; a user base, adopting control techniques; and a technical base, expanding the concepts of control. Both formal and informal mechanisms used by NASA to communicate a variety of technical advances are reviewed and certain examples of the expansion of the user base through technology transfer are given. Issues related to transfer of NASA-generated contamination control technology are emphasized.

Plasma processing conditions substantially influence circulating microRNA biomarker levels.

PubMed

Cheng, Heather H; Yi, Hye Son; Kim, Yeonju; Kroh, Evan M; Chien, Jason W; Eaton, Keith D; Goodman, Marc T; Tait, Jonathan F; Tewari, Muneesh; Pritchard, Colin C

2013-01-01

Circulating, cell-free microRNAs (miRNAs) are promising candidate biomarkers, but optimal conditions for processing blood specimens for miRNA measurement remain to be established. Our previous work showed that the majority of plasma miRNAs are likely blood cell-derived. In the course of profiling lung cancer cases versus healthy controls, we observed a broad increase in circulating miRNA levels in cases compared to controls and that higher miRNA expression correlated with higher platelet and particle counts. We therefore hypothesized that the quantity of residual platelets and microparticles remaining after plasma processing might impact miRNA measurements. To systematically investigate this, we subjected matched plasma from healthy individuals to stepwise processing with differential centrifugation and 0.22 µm filtration and performed miRNA profiling. We found a major effect on circulating miRNAs, with the majority (72%) of detectable miRNAs substantially affected by processing alone. Specifically, 10% of miRNAs showed 4-30x variation, 46% showed 30-1,000x variation, and 15% showed >1,000x variation in expression solely from processing. This was predominantly due to platelet contamination, which persisted despite using standard laboratory protocols. Importantly, we show that platelet contamination in archived samples could largely be eliminated by additional centrifugation, even in frozen samples stored for six years. To minimize confounding effects in microRNA biomarker studies, additional steps to limit platelet contamination for circulating miRNA biomarker studies are necessary. We provide specific practical recommendations to help minimize confounding variation attributable to plasma processing and platelet contamination.

Trace Contaminant Control for the International Space Station's Node 1- Analysis, Design, and Verification

NASA Technical Reports Server (NTRS)

Perry, J. L.

2017-01-01

Trace chemical contaminant generation inside crewed spacecraft cabins is a technical and medical problem that must be continuously evaluated. Although passive control through materials selection and active control by adsorption and catalytic oxidation devices is employed during normal operations of a spacecraft, contaminant buildup can still become a problem. Buildup is particularly troublesome during the stages between the final closure of a spacecraft during ground processing and the time that a crewmember enters for the first time during the mission. Typically, the elapsed time between preflight closure and first entry on orbit for spacecraft such as Spacelab modules was 30 days. During that time, the active contamination control systems are not activated and contaminants can potentially build up to levels which exceed the spacecraft maximum allowable concentrations (SMACs) specified by NASA toxicology experts. To prevent excessively high contamination levels at crew entry, the Spacelab active contamination control system was operated for 53 hours just before launch.

49 CFR 176.715 - Contamination control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination control. 176.715 Section 176.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Radioactive Materials § 176.715 Contamination control. Each hold, compartment, or deck area...

49 CFR 176.715 - Contamination control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Contamination control. 176.715 Section 176.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Radioactive Materials § 176.715 Contamination control. Each hold, compartment, or deck area...

49 CFR 176.715 - Contamination control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Contamination control. 176.715 Section 176.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Radioactive Materials § 176.715 Contamination control. Each hold, compartment, or deck area...

49 CFR 176.715 - Contamination control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Contamination control. 176.715 Section 176.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Requirements for Radioactive Materials § 176.715 Contamination control. Each hold, compartment, or deck area...

Influence of blood contamination during multimode adhesive application on the microtensile bond strength to dentin.

PubMed

Kucukyilmaz, E; Celik, E U; Akcay, M; Yasa, B

2017-12-01

The present study evaluated the effects of blood contamination performed at different steps of bonding on the microtensile bond strength (μTBS) of multimode adhesives to dentin when using the self-etch approach. Seventy-five molars were randomly assigned to three adhesive groups comprising 25 specimens each: two multimode adhesives [Single Bond Universal (SBU) and All-Bond Universal (ABU)] and a conventional one-step self-etch adhesive [Clearfil S3 Bond Plus (CSBP)]. Each group was subdivided as follows: (1) uncontaminated (control): bonding application/light curing as a positive control; (2) contamination-1 (cont-1): bonding application/light curing/blood contamination/dry as a negative control; (3) contamination-2 (cont-2): bonding application/light curing/blood contamination/rinse/dry; (4) contamination-3 (cont-3): bonding application/blood contamination/dry/bonding re-application/light curing; and (5) contamination-4 (cont-4): bonding application/blood contamination/rinse/dry/bonding re-application/light curing. Dentin specimens were prepared for μTBS testing after the composite resin application. Data were analyzed with two-way ANOVA and post-hoc tests (α = 0.05). μTBS values were similar in cont-3 groups, and ABU/cont-4 and corresponding control groups, but were significantly lower in the other groups than in their control groups (P < 0.05). Cont-1 groups showed the lowest μTBS values (P < 0.05). Neither decontamination method prevented the decrease in μTBS when contamination occurred after light curing. Drying the blood contaminants and reapplying the adhesive may regain the dentin adhesion when contamination occurs before light curing. Alternatively, rinsing and drying contaminants followed by adhesive re-application may be effective depending on adhesive type.

iPads, droids, and bugs: Infection prevention for mobile handheld devices at the point of care.

PubMed

Manning, Mary Lou; Davis, James; Sparnon, Erin; Ballard, Raylene M

2013-11-01

Health care providers are increasingly using wireless media tablets, such as the Apple iPad, especially in the hospital setting. In the absence of specific tablet disinfection guidelines the authors applied what is known about the contamination of other nonmedical mobile communication devices to create a "common sense" bundle to guide wireless media tablet infection prevention practices. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Best Management Practices (BMPs) for Soils Treatment Technologies

EPA Pesticide Factsheets

Document providing guidance on how to design and conduct soil remediation activities at RCRA and other hazardous waste sites so that transfers of contaminants from contaminated soil to other media are minimized.

Disinfection of human skin allografts in tissue banking: a systematic review report.

PubMed

Johnston, C; Callum, J; Mohr, J; Duong, A; Garibaldi, A; Simunovic, N; Ayeni, O R

2016-12-01

The use of skin allografts to temporarily replace lost or damaged skin is practiced worldwide. Naturally occurring contamination can be present on skin or can be introduced at recovery or during processing. This contamination can pose a threat to allograft recipients. Bacterial culture and disinfection of allografts are mandated, but the specific practices and methodologies are not dictated by standards. A systematic review of literature from three databases found 12 research articles that evaluated bioburden reduction processes of skin grafts. The use of broad spectrum antibiotics and antifungal agents was the most frequently identified disinfection method reported demonstrating reductions in contamination rates. It was determined that the greatest reduction in the skin allograft contamination rates utilized 0.1 % peracetic acid or 25 kGy of gamma irradiation at lower temperatures.

Removal of mercury by adsorption: a review.

PubMed

Yu, Jin-Gang; Yue, Bao-Yu; Wu, Xiong-Wei; Liu, Qi; Jiao, Fei-Peng; Jiang, Xin-Yu; Chen, Xiao-Qing

2016-03-01

Due to natural and production activities, mercury contamination has become one of the major environmental problems over the world. Mercury contamination is a serious threat to human health. Among the existing technologies available for mercury pollution control, the adsorption process can get excellent separation effects and has been further studied. This review is attempted to cover a wide range of adsorbents that were developed for the removal of mercury from the year 2011. Various adsorbents, including the latest adsorbents, are presented along with highlighting and discussing the key advancements on their preparation, modification technologies, and strategies. By comparing their adsorption capacities, it is evident from the literature survey that some adsorbents have shown excellent potential for the removal of mercury. However, there is still a need to develop novel, efficient adsorbents with low cost, high stability, and easy production and manufacture for practical utility.

Metabolic engineering of microbial competitive advantage for industrial fermentation processes.

PubMed

Shaw, A Joe; Lam, Felix H; Hamilton, Maureen; Consiglio, Andrew; MacEwen, Kyle; Brevnova, Elena E; Greenhagen, Emily; LaTouf, W Greg; South, Colin R; van Dijken, Hans; Stephanopoulos, Gregory

2016-08-05

Microbial contamination is an obstacle to widespread production of advanced biofuels and chemicals. Current practices such as process sterilization or antibiotic dosage carry excess costs or encourage the development of antibiotic resistance. We engineered Escherichia coli to assimilate melamine, a xenobiotic compound containing nitrogen. After adaptive laboratory evolution to improve pathway efficiency, the engineered strain rapidly outcompeted a control strain when melamine was supplied as the nitrogen source. We additionally engineered the yeasts Saccharomyces cerevisiae and Yarrowia lipolytica to assimilate nitrogen from cyanamide and phosphorus from potassium phosphite, and they outcompeted contaminating strains in several low-cost feedstocks. Supplying essential growth nutrients through xenobiotic or ecologically rare chemicals provides microbial competitive advantage with minimal external risks, given that engineered biocatalysts only have improved fitness within the customized fermentation environment. Copyright © 2016, American Association for the Advancement of Science.

Occurrence and risk assessment of phthalate esters (PAEs) in agricultural soils of the Sanjiang Plain, northeast China.

PubMed

Wang, He; Liang, Hong; Gao, Da-Wen

2017-08-01

This study looks at the pollution status of six priority control phthalate esters (PAEs) under different cultivation of agricultural soils in the Sanjiang Plain, northeast China. Results show the total concentration of PAEs ranged from 162.9 to 946.9 μg kg -1 with an average value of 369.5 μg kg -1 . PAE concentrations in three types of cultivated soils exhibited decreasing order paddy field (532.1 ± 198.1 μg kg -1 ) > vegetable field (308.2 ± 87.5 μg kg -1 ) > bean field (268.2 ± 48.3 μg kg -1 ). Di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the most abundant PAEs congeners. Compared with previous studies, agricultural soils in the Sanjiang Plain showed relatively low contamination levels. Anthropogenic activities such as cultivation practices and industrial emissions were associated with the distribution pattern of PAEs. Furthermore, human health risks of PAEs were estimated and the non-cancer risk shown negligible but carcinogenic risk of DEHP exceeded the threshold limits value. PAE contaminants originated from cultivation practices and intense anthropogenic activities result in placing the agricultural soils under a potential risk to human health and also to ecosystems in the Sanjiang Plain. Therefore, the contamination status of PAEs in agricultural soil and potential impacts on human health should attract considerable attention.

Process Upsets Involving Trace Contaminant Control Systems

NASA Technical Reports Server (NTRS)

Graf, John C.; Perry, Jay; Wright, John; Bahr, Jim

2000-01-01

Paradoxically, trace contaminant control systems that suffer unexpected upsets and malfunctions can release hazardous gaseous contaminants into a spacecraft cabin atmosphere causing potentially serious toxicological problems. Trace contaminant control systems designed for spaceflight typically employ a combination of adsorption beds and catalytic oxidation reactors to remove organic and inorganic trace contaminants from the cabin atmosphere. Interestingly, the same design features and attributes which make these systems so effective for purifying a spacecraft's atmosphere can also make them susceptible to system upsets. Cabin conditions can be contributing causes of phenomena such as adsorbent "rollover" and catalyst poisoning can alter a systems performance and in some in stances release contamination into the cabin. Evidence of these phenomena has been observed both in flight and during ground-based tests. The following discussion describes specific instances of system upsets found in trace contaminant control systems, groups these specific upsets into general hazard classifications, and recommends ways to minimize these hazards.

10 CFR 835.1102 - Control of areas.

Code of Federal Regulations, 2010 CFR

2010-01-01

... DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Radioactive Contamination Control § 835.1102 Control... transfer of removable contamination to locations outside of radiological areas under normal operating conditions. (b) Any area in which contamination levels exceed the values specified in appendix D of this part...

49 CFR 173.443 - Contamination control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Contamination control. 173.443 Section 173.443 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.443 Contamination control. (a) The level of...

49 CFR 173.443 - Contamination control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination control. 173.443 Section 173.443 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.443 Contamination control. (a) The level of...

49 CFR 173.443 - Contamination control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Contamination control. 173.443 Section 173.443 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.443 Contamination control. (a) The level of...

49 CFR 173.443 - Contamination control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Contamination control. 173.443 Section 173.443 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.443 Contamination control. (a) The level of...

Requirements and Sizing Investigation for the Constellation Space Suit Portable Life Support System Trace Contaminant Control

NASA Technical Reports Server (NTRS)

Jennings, Mallory A.; Paul, Heather L.; Waguespack, Glenn M.

2010-01-01

This presentation summarized the results of a trade study that evaluated whether trace contaminant control within the Constellation Spacesuit PLSS could be achieved without a Trace Contaminant Control System (TCCS) by relying on suit leakage, ullage loss from the carbon dioxide and humidity control system, and other factors. Mallory Jennings and Dr. Glenn Waguespack studied trace contaminant generation rates to verify that values reflected the latest designs for Constellation spacesuit system pressure garment materials and PLSS hardware. They also calculated TCCS sizing and conducted a literature survey to review the latest developments in trace contaminant technologies.

A Design Basis for Spacecraft Cabin Trace Contaminant Control

NASA Technical Reports Server (NTRS)

Perry, Jay L.

2009-01-01

Successful trace chemical contamination control is one of the components necessary for achieving good cabin atmospheric quality. While employing seemingly simple process technologies, sizing the active contamination control equipment must employ a reliable design basis for the trace chemical load in the cabin atmosphere. A simplified design basis that draws on experience gained from the International Space Station program is presented. The trace chemical contamination control design load refines generation source magnitudes and includes key chemical functional groups representing both engineering and toxicology challenges.

Quantification of BMPs Selection and Spatial Placement Impact on Water Quality Controlling Plans in Lower Bear River Watershed, Utah

NASA Astrophysics Data System (ADS)

Salha, A. A.; Stevens, D. K.

2016-12-01

The aim of the watershed-management program in Box Elder County, Utah set by Utah Division of Water Quality (UDEQ) is to evaluate the effectiveness and spatial placement of the implemented best-management practices (BMP) for controlling nonpoint-source contamination at watershed scale. The need to evaluate the performance of BMPs would help future policy and program decisions making as desired end results. The environmental and costs benefits of BMPs in Lower Bear River watershed have seldom been measured beyond field experiments. Yet, implemented practices have rarely been evaluated at the watershed scale where the combined effects of variable soils, climatic conditions, topography and land use/covers and management conditions may significantly change anticipated results and reductions loads. Such evaluation requires distributed watershed models that are necessary for quantifying and reproducing the movement of water, sediments and nutrients. Soil and Water Assessment Tool (SWAT) model is selected as a watershed level tool to identify contaminant nonpoint sources (critical zones) and areas of high pollution risks. Water quality concerns have been documented and are primarily attributed to high phosphorus and total suspended sediment concentrations caused by agricultural and farming practices (required load is 460 kg/day of total phosphorus based on 0.075 mg/l and an average of total suspended solids of 90 mg/l). Input data such as digital elevation model (DEM), land use/Land cover (LULC), soils, and climate data for 10 years (2000-2010) is utilized along with observed water quality at the watershed outlet (USGS) and some discrete monitoring points within the watershed. Statistical and spatial analysis of scenarios of management practices (BMP's) are not implemented (before implementation), during implementation, and after BMP's have been studied to determine whether water quality of the two main water bodies has improved as required by the LBMR watershed's TMDL and if the BMPs are cost-effectively targeting the critical zones.

Scaleable processes for the manufacture of therapeutic quantities of plasmid DNA.

PubMed

Shamlou, Parviz Ayazi

2003-06-01

The need for scaleable processes to manufacture therapeutic plasmid DNA (pDNA) is easy to overlook when attention is focused primarily on vector design and establishment of early clinical results. pDNA is a large molecule and has properties that are similar to those of the contaminating chromosomal DNA. These, combined with the low initial concentration of plasmids in the host cell, provide unique process challenges that require significant upfront design to establish robust manufacturing processes that can also comply with current Good Manufacturing Practice ('cGMP') and produce milligram-to-kilogram quantities of pDNA product. This review describes promising scaleable processes that are currently being assessed for production of therapeutic supercoiled pDNA. Fermentation strategies for improving supercoiled plasmid yield and reducing contaminant concentrations are reviewed, and downstream processes are assessed for their ability to efficiently remove cellular contaminants, separate the supercoiled form of the pDNA from its open circular and linear forms, and prepare the purified drug substance for formulation. Current strategies are presented for developing stable delivery systems, and approaches to quality assurance and quality control are discussed.

A Risk-Based Characterization of Sediment Contamination by Legacy and Emergent Contaminants of Concern in Coastal British Columbia, Canada.

PubMed

Morales-Caselles, Carmen; Desforges, Jean-Pierre W; Dangerfield, Neil; Ross, Peter S

2017-08-01

Sediments have long been used to help describe pollution sources, contaminated sites, trends over time, and habitat quality for marine life. We collected surficial sediments from 12 sites at an average seawater depth of 25 m in three near-urban areas of the Salish Sea (British Columbia, Canada) to investigate habitat quality for marine life, including heavily contaminated killer whales. Samples were analyzed using high-resolution instrumentation for a wide variety of congeners of polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCDD), polybrominated biphenyls, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans, organochlorine pesticides, and polychlorinated naphthalenes (PCNs). The top six contaminant classes detected in sediments were ∑PCB > ∑PBDE > ∑PCDD/F > DDT > ∑HBCDD > ∑PCN. Near-urban harbor sediments had up to three orders of magnitude higher concentrations of contaminants than more remote sites. With limited tools available to characterize biological risks associated with complex mixtures in the real world, we applied several available approaches to prioritize the pollutant found in our study: (1) sediment quality guidelines from the Canadian Council of Ministers of the Environment where available; (2) US NOAA effects range low and other international guidelines; (3) total TEQ for dioxin-like PCBs for the protection of mammals; and (4) the calculation of risk quotients. Our findings provide an indication of the state of contamination of coastal environments in British Columbia and guidance for chemical regulations and priority setting, as well as management actions including best-practices, dredging, disposal at sea, and source control. In this regard, the legacy PCB and the emergent PBDEs should command continued priority monitoring.

Reduction in Blood Culture Contamination Through Use of Initial Specimen Diversion Device.

PubMed

Rupp, Mark E; Cavalieri, R Jennifer; Marolf, Cole; Lyden, Elizabeth

2017-07-15

Blood culture contamination is a clinically significant problem that results in patient harm and excess cost. In a prospective, controlled trial at an academic center Emergency Department, a device that diverts and sequesters the initial 1.5-2 mL portion of blood (which presumably carries contaminating skin cells and microbes) was tested against standard phlebotomy procedures in patients requiring blood cultures due to clinical suspicion of serious infection. In sum, 971 subjects granted informed consent and were enrolled resulting in 904 nonduplicative subjects with 1808 blood cultures. Blood culture contamination was significantly reduced through use of the initial specimen diversion device™ (ISDD) compared to standard procedure: (2/904 [0.22%] ISDD vs 16/904 [1.78%] standard practice, P = .001). Sensitivity was not compromised: true bacteremia was noted in 65/904 (7.2%) ISDD vs 69/904 (7.6%) standard procedure, P = .41. No needlestick injuries or potential bloodborne pathogen exposures were reported. The monthly rate of blood culture contamination for all nurse-drawn and phlebotomist-drawn blood cultures was modeled using Poisson regression to compare the 12-month intervention period to the 6 month before and after periods. Phlebotomists (used the ISDD) experienced a significant decrease in blood culture contamination while the nurses (did not use the ISDD) did not. In sum, 73% of phlebotomists completed a post-study anonymous survey and widespread user satisfaction was noted. Use of the ISDD was associated with a significant decrease in blood culture contamination in patients undergoing blood cultures in an Emergency Department setting. NCT02102087. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Trace Contaminant Control During the International Space Station's On-Orbit Assembly and Outfitting

NASA Technical Reports Server (NTRS)

Perry, J. L.

2017-01-01

Achieving acceptable cabin air quality must balance competing elements during spacecraft design, assembly, ground processing, and flight operations. Among the elements that contribute to the trace chemical contaminant load and, therefore, the cabin air quality aboard crewed spacecraft are the vehicle configuration, crew size and activities, mission duration and objectives, materials selection, and vehicle manufacturing and preflight ground processing methods. Trace chemical contaminants produced from pervasive sources such as equipment offgassing, human metabolism, and cleaning fluids during preflight ground processing present challenges to maintaining acceptable cabin air quality. To address these challenges, both passive and active contamination control techniques are used during a spacecraft's design, manufacturing, preflight preparation, and operational phases. Passive contamination control methods seek to minimize the equipment offgassing load by selecting materials, manufacturing processes, preflight preparation processes, and in-flight operations that have low chemical offgassing characteristics. Passive methods can be employed across the spacecraft's entire life cycle from conceptual design through flight operations. However, because the passive contamination control techniques cannot fully eliminate the contaminant load, active contamination control equipment must be deployed aboard the spacecraft to purify and revitalize the cabin atmosphere during in-flight operations. Verifying that the passive contamination control techniques have successfully maintained the total trace contaminant load within the active contamination control equipment's capabilities occurs late in the preflight preparation stages. This verification consists of subjecting the spacecraft to an offgassing test to determine the trace contaminant load. This load is then assessed versus the active contamination control equipment's capabilities via trace contaminant control (TCC) engineering analysis. During the International Space Station's (ISS's) on-orbit assembly and outfitting, a series of engineering analyses were conducted to evaluate how effective the passive TCC methods were relative to providing adequate operational margin for the active TCC equipment's capabilities aboard the ISS. These analyses were based on habitable module and cargo vehicle offgassing test results. The offgassing test for a fully assembled module or cargo vehicle is an important preflight spacecraft evaluation method that has been used successfully during all crewed spacecraft programs to provide insight into how effectively the passive contamination control methods limit the equipment offgassing component of the overall trace contaminant generation load. The progression of TCC assessments beginning in 1998 with the ISS's first habitable element launch and continuing through the final pressurized element's arrival in 2010 are presented. Early cargo vehicle flight assessments between 2008 and 2011 are also presented as well as a discussion on predictive methods for assessing cargo via a purely analytical technique. The technical approach for TCC employed during this 13-year period successfully maintained the cabin atmospheric quality within specified parameters during the technically challenging ISS assembly and outfitting stages. The following narrative provides details on the important role of spacecraft offgassing testing, trace contaminant performance requirements, and flight rules for achieving the ultimate result-a cabin environment that enables people to live and work safely in space.

Biological Remediation of Petroleum Contaminants

NASA Astrophysics Data System (ADS)

Kuhad, Ramesh Chander; Gupta, Rishi

Large volumes of hazardous wastes are generated in the form of oily sludges and contaminated soils during crude oil transportation and processing. Although many physical, chemical and biological treatment technologies are available for petroleum contaminants petroleum contaminants in soil, biological methods have been considered the most cost-effective. Practical biological remediation methods typically involve direct use of the microbes naturally occurring in the contaminated environment and/or cultured indigenous or modified microorganisms. Environmental and nutritional factors, including the properties of the soil, the chemical structure of the hydrocarbon(s), oxygen, water, nutrient availability, pH, temperature, and contaminant bioavailability, can significantly affect the rate and the extent of hydrocarbon biodegradation hydrocarbon biodegradation by microorganisms in contaminated soils. This chapter concisely discusses the major aspects of bioremediation of petroleum contaminants.

Outbreak of escherichia coli O157: H7 infections after Petting Zoo visits, North Carolina State Fair, October-November 2004.

PubMed

Goode, Brant; O'Reilly, Ciara; Dunn, John; Fullerton, Kathleen; Smith, Stacey; Ghneim, George; Keen, James; Durso, Lisa; Davies, Megan; Montgomery, Sue

2009-01-01

To identify cases, describe the outbreak, implement control measures, and identify factors associated with infection or protection from infection, including contact with animals and hand hygiene practices. Case finding, a case-control study of 45 cases and 188 controls, environmental investigation, and molecular subtyping of clinical and environmental Escherichia coli O157:H7 isolates. The 2004 North Carolina State Fair. Case patients were fair visitors who had laboratory-confirmed E coli O157 infections, hemolytic uremic syndrome (HUS) diagnoses, or bloody diarrheal illnesses. Control subjects were recruited from a randomized list of persons who had purchased fair tickets online. Environmental samples from the fairgrounds were obtained from locations that had held animals during the fair. Main Exposure Visiting a petting zoo. Case finding: Summary descriptive statistics of suspected, probable, or confirmed E coli O157:H7 infections, signs, symptoms, and HUS. Environmental investigation: E coli O157:H7 isolates, pulsed-field gel electrophoresis patterns, and spatial distribution of source locations. Case-control study: Odds ratios (ORs) comparing reported fair-related activities, hygiene practices, and zoonotic disease knowledge with outcome. A total of 108 case patients were ascertained, including 41 with laboratory-confirmed illness and 15 who experienced HUS. Forty-five case patients and 188 controls were enrolled in the case-control study. Visits to a petting zoo having substantial environmental E coli O157:H7 contamination were associated with illness (age-adjusted OR, 8.2; 95% confidence interval [CI], 3.3-20.3). Among children 5 years or younger who had visited the implicated petting zoo, contact with animal manure (OR, 6.9; 95% CI, 2.2-21.9) and hand-to-mouth behaviors (OR, 10.6; 95% CI, 2.0-55.0) were associated with illness. Reported hand hygiene practices did not differ significantly (OR, 1.8; 95% CI, 0.3-9.5). Reported awareness of the risk for zoonotic disease was protective (OR, 0.1; 95% CI, 0.03-0.5). Environmental samples from the petting zoo implicated in the case-control study yielded E coli O157:H7, with indistinguishable pulsed-field gel electrophoresis patterns from the predominant strain. We describe one of the largest petting zoo outbreaks of E coli O157:H7 to date. Persons became infected after contact with manure and engaging in hand-to-mouth behaviors in a petting zoo having substantial E coli O157:H7 contamination. Use of alcohol-based hand-sanitizing gels was not protective, although knowledge of the risk for zoonotic infection was protective. Future investigations in similar outbreaks should assess risks for infection and protective measures (eg, physical barriers separating visitors from animal manure, education, and appropriate hand hygiene practices).

Widespread legacy brine contamination from oil production reduces survival of chorus frog larvae

USGS Publications Warehouse

Hossack, Blake R.; Puglis, Holly J.; Battaglin, William A.; Anderson, Chauncey; Honeycutt, Richard; Smalling, Kelly

2017-01-01

Advances in drilling techniques have facilitated a rapid increase in hydrocarbon extraction from energy shales, including the Williston Basin in central North America. This area overlaps with the Prairie Pothole Region, a region densely populated with wetlands that provide numerous ecosystem services. Historical (legacy) disposal practices often released saline co-produced waters (brines) with high chloride concentrations, affecting wetland water quality directly or persisting in sediments. Despite the potential threat of brine contamination to aquatic habitats, there has been little research into its ecological effects. We capitalized on a gradient of legacy brine-contaminated wetlands in northeast Montana to conduct laboratory experiments to assess variation in survival of larval Boreal Chorus Frogs (Pseudacris maculata) reared on sediments from 3 local wetlands and a control source. To help provide environmental context for the experiment, we also measured chloride concentrations in 6 brine-contaminated wetlands in our study area, including the 2 contaminated sites used for sediment exposures. Survival of frog larvae during 46- and 55-day experiments differed by up to 88% among sediment sources (Site Model) and was negatively correlated with potential chloride exposure (Chloride Model). Five of the 6 contaminated wetlands exceeded the U.S. EPA acute benchmark for chloride in freshwater (860 mg/L) and all exceeded the chronic benchmark (230 mg/L). However, the Wetland Site model explained more variation in survival than the Chloride Model, suggesting that chloride concentration alone does not fully reflect the threat of contamination to aquatic species. Because the profiles of brine-contaminated sediments are complex, further surveys and experiments are needed across a broad range of conditions, especially where restoration or remediation actions have reduced brine-contamination. Information provided by this study can help quantify potential ecological threats and help land managers prioritize conservation strategies as part of responsible and sustainable energy development.

Payload/orbiter contamination control requirement study: Preliminary contamination mission support plan. [a management analysis of project planning of spacecraft sterilization

NASA Technical Reports Server (NTRS)

Bareiss, L. E.; Hooper, V. W.; Ress, E. B.

1976-01-01

Progress is reported on the mission support plan and those support activities envisioned to be applicable and necessary during premission and postmission phases of the Spacelab program. The purpose, role, and requirements of the contamination control operations for the first two missions of the Spacelab equipped Space Transportation System are discussed. The organization of the contamination control operation and its relationship to and interfaces with other mission support functions is also discussed. Some specific areas of contamination to be investigated are treated. They are: (1) windows and viewports, (2) experiment equipment, (3) thermal control surfaces, (4) the contaminant induced atmosphere (as differentiated from the normal ambient atmosphere at the orbit altitude), and (5) optical navigation instruments.

Results of the Trace Contaminant Control Needs Evaluation and Sizing Study for Space Suit Life Support Development

NASA Technical Reports Server (NTRS)

Paul, Heather L.; Jennings, Mallory A.

2009-01-01

The Trace Contaminant Control System (TCCS), located within the ventilation loop of the Portable Life Support System (PLSS) of the Constellation Space Suit Element (CSSE), is responsible for removing hazardous trace contaminants from the space suit ventilation flow. This paper summarizes the results of a trade study that evaluated if trace contaminant control could be accomplished without a TCCS, relying on suit leakage, ullage loss from the carbon dioxide and humidity control system, and other factors. Trace contaminant generation rates were revisited to verify that values reflect the latest designs for CSSE pressure garment materials and PLSS hardware. Additionally, TCCS sizing calculations were performed and a literature survey was conducted to review the latest developments in trace contaminant technologies.

Panel summary of recommendations

NASA Technical Reports Server (NTRS)

Dunbar, Bonnie J.; Coleman, Martin E.; Mitchell, Kenneth L.

1990-01-01

The following Space Station internal contamination topics were addressed: past flight experience (Skylab and Spacelab missions); present flight activities (Spacelabs and Soviet Space Station Mir); future activities (materials science and life science experiments); Space Station capabilities (PPMS, FMS, ECLSS, and U.S. Laboratory overview); manned systems/crew safety; internal contamination detection; contamination control - stowage and handling; and contamination control - waste gas processing. Space Station design assumptions are discussed. Issues and concerns are discussed as they relate to (1) policy and management, (2) subsystem design, (3) experiment design, and (4) internal contamination detection and control. The recommendations generated are summarized.

The Fate of Trace Contaminants in a Crewed Spacecraft Cabin Environment

NASA Technical Reports Server (NTRS)

Perry, Jay L.; Kayatin, Matthew J.

2016-01-01

Trace chemical contaminants produced via equipment offgassing, human metabolic sources, and vehicle operations are removed from the cabin atmosphere by active contamination control equipment and incidental removal by other air quality control equipment. The fate of representative trace contaminants commonly observed in spacecraft cabin atmospheres is explored. Removal mechanisms are described and predictive mass balance techniques are reviewed. Results from the predictive techniques are compared to cabin air quality analysis results. Considerations are discussed for an integrated trace contaminant control architecture suitable for long duration crewed space exploration missions.

Analysis of Food Contaminants, Residues, and Chemical Constituents of Concern

NASA Astrophysics Data System (ADS)

Ismail, Baraem; Reuhs, Bradley L.; Nielsen, S. Suzanne

The food chain that starts with farmers and ends with consumers can be complex, involving multiple stages of production and distribution (planting, harvesting, breeding, transporting, storing, importing, processing, packaging, distributing to retail markets, and shelf storing) (Fig. 18.1). Various practices can be employed at each stage in the food chain, which may include pesticide treatment, agricultural bioengineering, veterinary drug administration, environmental and storage conditions, processing applications, economic gain practices, use of food additives, choice of packaging material, etc. Each of these practices can play a major role in food quality and safety, due to the possibility of contamination with or introduction (intentionally and nonintentionally) of hazardous substances or constituents. Legislation and regulation to ensure food quality and safety are in place and continue to develop to protect the stakeholders, namely farmers, consumers, and industry. [Refer to reference (1) for information on regulations of food contaminants and residues.

Evaluation of a Candidate Trace Contaminant Control Subsystem Architecture: The High Velocity, Low Aspect Ratio (HVLA) Adsorption Process

NASA Technical Reports Server (NTRS)

Kayatin, Matthew J.; Perry, Jay L.

2017-01-01

Traditional gas-phase trace contaminant control adsorption process flow is constrained as required to maintain high contaminant single-pass adsorption efficiency. Specifically, the bed superficial velocity is controlled to limit the adsorption mass-transfer zone length relative to the physical adsorption bed; this is aided by traditional high-aspect ratio bed design. Through operation in this manner, most contaminants, including those with relatively high potential energy are readily adsorbed. A consequence of this operational approach, however, is a limited available operational flow margin. By considering a paradigm shift in adsorption architecture design and operations, in which flows of high superficial velocity are treated by low-aspect ratio sorbent beds, the range of well-adsorbed contaminants becomes limited, but the process flow is increased such that contaminant leaks or emerging contaminants of interest may be effectively controlled. To this end, the high velocity, low aspect ratio (HVLA) adsorption process architecture was demonstrated against a trace contaminant load representative of the International Space Station atmosphere. Two HVLA concept packaging designs (linear flow and radial flow) were tested. The performance of each design was evaluated and compared against computer simulation. Utilizing the HVLA process, long and sustained control of heavy organic contaminants was demonstrated.

Cell lines authentication and mycoplasma detection as minimun quality control of cell lines in biobanking.

PubMed

Corral-Vázquez, C; Aguilar-Quesada, R; Catalina, P; Lucena-Aguilar, G; Ligero, G; Miranda, B; Carrillo-Ávila, J A

2017-06-01

Establishment of continuous cell lines from human normal and tumor tissues is an extended and useful methodology for molecular characterization of cancer pathophysiology and drug development in research laboratories. The exchange of these cell lines between different labs is a common practice that can compromise assays reliability due to contamination with microorganism such as mycoplasma or cells from different flasks that compromise experiment reproducibility and reliability. Great proportions of cell lines are contaminated with mycoplasma and/or are replaced by cells derived for a different origin during processing or distribution process. The scientific community has underestimated this problem and thousand of research experiment has been done with cell lines that are incorrectly identified and wrong scientific conclusions have been published. Regular contamination and authentication tests are necessary in order to avoid negative consequences of widespread misidentified and contaminated cell lines. Cell banks generate, store and distribute cell lines for research, being mandatory a consistent and continuous quality program. Methods implementation for guaranteeing both, the absence of mycoplasma and authentication in the supplied cell lines, has been performed in the Andalusian Health System Biobank. Specifically, precise results were obtained using real time PCR detection for mycoplasma and 10 STRs identification by capillary electrophoresis for cell line authentication. Advantages and disadvantages of these protocols are discussed.

Aflatoxin M1 contamination of milk and ice cream in Abeokuta and Odeda local governments of Ogun State, Nigeria.

PubMed

Atanda, Olusegun; Oguntubo, Adenike; Adejumo, Oloyede; Ikeorah, John; Akpan, Iyang

2007-07-01

A survey was undertaken to determine the aflatoxin M(1) contamination of milk and some locally produced dairy products in Abeokuta and Odeda local governments of Ogun State, Nigeria. Samples of human and cow milk, yoghurt, "wara", ice cream and "nono" were collected randomly within the local governments and analysed for aflatoxin M(1) using the two-dimensional TLC. Aflatoxin M(1) contamination in the range of 2.04-4.00 microg l(-1) was noticed only in milk and ice cream. In particular, samples of human milk, cow milk and ice cream recorded high scores of 4.0 microg l(-1), 2.04 microg l(-1) and 2.23 microg l(-1), respectively in Abeokuta local governments and a score of 4.0 microg l(-1) for cow milk in Odeda local government. This indicates a high level contamination in the local governments since the weighted mean concentration of aflatoxin M1 in milk for African diet is 0.002 microg l(-1). Therefore the concentration of AFB1 in feeds which is transformed to AFM1 in milk should be reduced by good manufacturing and good storage practices. Furthermore, there is need for stringent quality control during processing and distribution of these products.

Impact of wastewater-irrigation on in-household water contamination. A cohort study among urban farmers in Ahmedabad, India.

PubMed

Falkenberg, Timo; Saxena, Deepak; Kistemann, Thomas

2018-10-15

This cohort study explores the contribution of wastewater irrigation, in the context of WASH (Water, Sanitation, Hygiene), on in-household water contamination among urban farming households in Ahmedabad, India. Drinking water samples of 204 households in four peri-urban farming communities were collected from the point-of-source (PoS) and point-of-use (PoU) of each household four times over the 12-month follow-up period. Next to the quantification of E. coli, three household surveys (baseline, hygiene and farm) were conducted. Additionally, an observational spot-check was undertaken in bi-monthly intervals throughout the follow-up period. Significant positive differences in water quality between PoS and PoU samples were identified in 78% of households. During the monsoon, the peak of contamination, only 6% of households had access to safe drinking water at PoU. The Average Treatment Effect (ATE) of wastewater irrigation indicates an adverse effect on in-household water contamination, larger in effect size than the mitigation effect of access to sanitation or personal hygiene. To control transmission of fecal pathogens, effective barriers are required for wastewater irrigation similar to the necessity of ensuring access to sanitation and practicing adequate hygiene behavior. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Quantifying the rambunctious journey of the anesthesia provider's hands during simulated, routine care.

PubMed

Biddle, Chuck; Robinson, Kathryn; Pike, Benjamin; Kammerman, Michael; Gay, Beverly; Verhulst, Brad

2016-08-01

The role of anesthesia providers in dispersing potentially pathogenic material from one patient to another during intraoperative care needs further study. In this study we aimed (1) to quantify the dispersion of a surrogate pathogen from a simulated patient's mouth to the anesthesia workstation during routine anesthetic induction, (2) to test the hypothesis that there would be fewer contamination sites by providers who used a double-gloving technique, and (3) to examine the effectiveness of between-case anesthesia apparatus disinfection. Twenty subjects were randomized to a single pair of gloves group (group 1) or a double-gloved group (group 2) and completed a simulated general anesthesia induction, completing a standardized set of interventions. Dispersion of a surrogate pathogen dye placed in the oral cavity of the simulated patient was tracked by a blinded observer and photography. Standard cleaning of the workstation was performed, and residual dye was quantified. Group performance was plotted using regression analysis and rate of contamination compared using parametric statistics. Group 1 contaminated an average of 16.0 (SEM = 0.89) sites compared with group 2, who contaminated an average of 7.6 (SEM = 0.85). The cart drawers, gas flow dials, medication vials, and ventilator controls were significantly contaminated by group 1, but not by group 2 (P < .05 in all cases). There were similar rates of contamination in both groups for the airway equipment, breathing system, intravenous access ports, and the roll of tape used to secure the endotracheal tube. Once the airway management phase of the induction ended, new site contamination continued at a high rate in group 1 but not group 2. A double-gloving technique was associated with less spread of an oral inoculum to the workstation but was not uniformly protective. Between-case cleaning was ineffective in removing the contaminant, indicating that biologic material from one patient may be present when subsequent patients are cared for. This suggests risks for the current patient (eg, skin or oral site transfer to an intravenous site) and also may place future patients at risk. Importantly, using models that simulate actual clinical events can inform clinical practice and decipher challenging areas of ergonomics. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Practical applications of nondestructive materials characterization

NASA Astrophysics Data System (ADS)

Green, Robert E., Jr.

1992-10-01

Nondestructive evaluation (NDE) techniques are reviewed for applications to the industrial production of materials including microstructural, physical, and chemical analyses. NDE techniques addressed include: (1) double-pulse holographic interferometry for sealed-package leak testing; (2) process controls for noncontact metals fabrication; (3) ultrasonic detections of oxygen contamination in titanium welds; and (4) scanning acoustic microscopy for the evaluation of solder bonds. The use of embedded sensors and emerging NDE concepts provides the means for controlling the manufacturing and quality of quartz crystal resonators, nickel single-crystal turbine blades, and integrated circuits. Advances in sensor technology and artificial intelligence algorithms and the use of embedded sensors combine to make NDE technology highly effective in controlling industrial materials manufacturing and the quality of the products.

Installation Restoration Program. Preliminary Assessment: 192nd Tactical Fighter Group, Virginia Air National Guard, Richmond International Airport, Sandston, Virginia

DTIC Science & Technology

1989-02-01

contaminated by past disposal practices. Sampling and analysis was not included in the PA. B. MAJOR FINDINGS The Air National Guard has utilized...with 23 Base personnel and the field surveys identified 3 potentially contaminated sites resulting from past disposal, storage, and/or spills and leaks...characteristic petroleum odor. With visible evidence of released contaminants , there is potential for contaminant migration by shallow groundwater. Site No. 3

Chemical coagulation-based processes for trace organic contaminant removal: current state and future potential.

PubMed

Alexander, Jonathan T; Hai, Faisal I; Al-Aboud, Turki M

2012-11-30

Trace organic contaminants have become an increasing cause of concern for governments and water authorities as they attempt to respond to the potential challenges posed by climate change by implementing sustainable water cycle management practices. The augmentation of potable water supplies through indirect potable water reuse is one such method currently being employed. Given the uncertainty surrounding the potential human health impacts of prolonged ingestion of trace organic contaminants, it is vital that effective and sustainable treatment methods are utilized. The purpose of this article is to provide a comprehensive literature review of the performance of the chemical coagulation process in removing trace organic contaminants from water. This study evaluated the removal data collated from recent research relating to various trace organic contaminants during the coagulation process. It was observed that there is limited research data relating to the removal of trace organic contaminants using coagulation. The findings of this study suggest that there is a gap in the current research investigating the potential of new types of coagulants and exploring coagulation-based hybrid processes to remove trace organic contaminants from water. The data analysed in this study regarding removal efficiency suggests that, even for the significantly hydrophobic compounds, hydrophobicity is not the sole factor governing removal of trace organic contaminants by coagulation. This has important implications in that the usual practice of screening coagulants based on turbidity (suspended solid) removal proves inadequate in the case of trace organic contaminant removal. Copyright © 2012 Elsevier Ltd. All rights reserved.

Real and Perceived Risks for Mycotoxin Contamination in Foods and Feeds: Challenges for Food Safety Control

PubMed Central

Milićević, Dragan R.; Škrinjar, Marija; Baltić, Tatjana

2010-01-01

Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption of mycotoxins have occurred for many centuries. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health in general, and induce diverse and powerful toxic effects in test systems: some are carcinogenic, mutagenic, teratogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermotoxic and neurotoxic. Although mycotoxin contamination of agricultural products still occurs in the developed world, the application of modern agricultural practices and the presence of a legislatively regulated food processing and marketing system have greatly reduced mycotoxin exposure in these populations. However, in developing countries, where climatic and crop storage conditions are frequently conducive to fungal growth and mycotoxin production, much of the population relies on subsistence farming or on unregulated local markets. Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot of food commodity and, consequently, of the impact of mycotoxins on human and animal health. PMID:22069600

Tracking sources of Clostridium botulinum type E contamination in seal meat.

PubMed

Leclair, Daniel; Farber, Jeffrey M; Pagotto, Franco; Suppa, Sandy; Doidge, Bill; Austin, John W

2017-01-01

Botulism in Nunavik, Quebec is associated with the consumption of aged marine mammal meat and fat. The objective was to identify meat handling practices presenting a risk of contamination of seal meat with C. botulinum. Potential sources of contamination were assessed through interviews with igunaq producers from five communities of Nunavik. These sources were verified by detection and isolation of C. botulinum from igunaq prepared in the field from seal carcasses. Interviews indicated practices presenting a risk for contamination included: placing meat or fat on coastal rocks, using seawater for rinsing, and ageing meat in inverted seal skin pouches. Although the presence of C. botulinum type E spores was detected in only two of 32 (6.3%) meat or fat samples collected during the butchering process, two of four igunaq preparations from these samples contained type E botulinum toxin. Analysis of C. botulinum type E isolates recovered from these preparations indicated that shoreline soil may be a source of contamination. Seal meat and fat may be contaminated with C. botulinum type E during the butchering process. Measures can be adopted to reduce the risks of contamination in the field and possibly decrease the incidence of type E botulism in Nunavik.

Controlling droplet-transmitted respiratory infections

PubMed Central

Hogg, William; Huston, Patricia

2006-01-01

OBJECTIVE To promote incorporation of new guidelines on control of respiratory infections into family physicians’ practices. SOURCES OF INFORMATION The World Health Organization website on pandemic influenza, the Canadian Pandemic Influenza Plan, the Ontario guidelines on respiratory infection control, and research on implementing guidelines into family practice were reviewed. We also researched and calculated what the costs of implementing the guidelines would be. MAIN MESSAGE Effective control of respiratory infections in physicians’ offices can be achieved by displaying signs in the waiting room, having reception staff give masks to patients with cough and fever, instructing these patients to clean their hands with alcohol gel and to sit at least 1 m from others, inquiring about patients’ or their close contacts’ recent travel, using disinfectant wipes to clean possibly contaminated surfaces in waiting rooms and examining areas, and having staff and care providers wear masks and wash hands or use alcohol gel. The approximate annual cost of incorporating the guidelines is about $800 per physician. CONCLUSION Because the outbreak of an influenza pandemic is likely imminent, implementing standard guidelines for control of respiratory infections in primary care offices seems wise. Following these guidelines would help prevent patients and staff from contracting serious respiratory illnesses. PMID:17279182

Prevention of EP Migratory Contamination in a Cluster Randomized Trial to Increase tPA Use in Stroke (The INSTINCT Trial)

PubMed Central

Weston, Victoria C.; Meurer, William J.; Frederiksen, Shirley M.; Fox, Allison K.; Scott, Phillip A.

2016-01-01

Objectives Cluster randomized trials (CRTs) are increasingly utilized to evaluate quality improvement interventions aimed at healthcare providers. In trials testing emergency department interventions, migration of emergency physicians (EPs) between hospitals is an important concern, as contamination may affect both internal and external validity. We hypothesized that geographically isolating emergency departments would prevent migratory contamination in a CRT designed to increase ED delivery of tPA in stroke (The INSTINCT Trial). Methods INSTINCT was a prospective, cluster randomized, controlled trial. 24 Michigan community hospitals were randomly selected in matched pairs for study. Contamination was defined at the cluster level, with substantial contamination defined a priori as >10% of EPs affected. Non-adherence, total crossover (contamination + non-adherence), migration distance and characteristics were determined. Results 307 emergency physicians were identified at all sites. Overall, 7 (2.3%) changed study sites. 1 moved between control sites, leaving 6 (2.0%) total crossovers. Of these, 2 (0.7%) moved from intervention to control (contamination) and 4 (1.3%) moved from control to intervention (non-adherence). Contamination was observed in 2 of 12 control sites, with 17% and 9% contamination of the total site EP workforce at follow-up, respectively. Average migration distance was 42 miles for all EPs moving in the study and 35 miles for EPs moving from intervention to control sites. Conclusion The mobile nature of emergency physicians should be considered in the design of quality improvement CRTs. Increased reporting of contamination in CRTs is encouraged to clarify thresholds and facilitate CRT design. PMID:25440230

Reprocessing and reuse of urological armamentarium: How correct are we!

PubMed Central

Raval, Krutik Vipulbhai; Chaudhari, Rajeev; Khant, Shahil Rameshbhai; Joglekar, Omkar; Patel, Dipen

2017-01-01

Healthcare is expensive for a large proportion of the population in spite of high per capita income and good health insurance penetration. In an effort to reduce cost of the procedure, reprocessing of devices was started in the late 1970s. Reprocessing practice includes various measures such as proper cleaning, disinfection, and sterilization procedures. As reprocessing is aimed at reducing cost, there is a potential risk of compromising patient safety due to cross contamination after inadequate sterilization. There is also risk of performance alteration of urological reprocessed devices during sterilization/disinfection processing. Therefore, there is a need for formulating proper guidelines to decide methods of reprocessing for various urological equipment. There is also need to discuss the problematic areas that urologists face and to find their solutions. A PubMed search was made in September 2016, using key words “reprocessing of medical devices,” “Single Use Devices,” “methods of reprocessing of devices in clinical practice,” “use of formalin chamber,” “urological disposable sterilization,” etc., After excluding duplicates, all English articles were reviewed by title and abstract. Full texts of selected articles were obtained, and these articles were cross-referenced to find any other related articles. All the articles were reviewed. A product can be reused if it can be economically reprocessed with validated protocols with preservation of its function. There is no reason to discard it after one use. This practice is useful for controlling economics of a urological case and to reduce the financial burden. Current Food and Drug Administration guidelines are stringent. The contamination described to test the sterilization process in the suggested guidelines actually does never exist in clinical practice. Therefore, new guidelines considering the clinical practice scenario are desirable. PMID:28479760

Hot and steamy: outbreak of Bacillus cereus in Singapore associated with construction work and laundry practices.

PubMed

Balm, M N D; Jureen, R; Teo, C; Yeoh, A E J; Lin, R T P; Dancer, S J; Fisher, D A

2012-08-01

A sudden increase in invasive infections caused by Bacillus cereus group organisms prompted an investigation at the National University Hospital in Singapore. To describe the investigation and management and subsequent difficulties controlling the outbreak. Clinical case reviews were performed on all patients with B. cereus group recovered from clinical samples. Widespread environmental sampling was performed followed by review of hospital ventilation systems, domestic cleaning and laundry practices. B. cereus was recovered from 171 patients during a six-month period coinciding with large-scale construction work beside the hospital. Most patients presented with bacteraemia (146/171; 85.4%) with 46/171 (26.9%) requiring extended treatment courses with vancomycin or other interventions. Sampling confirmed extensive airborne dispersal inside the hospital, including isolation rooms and air-conditioned wards. Hospital linen was heavily contaminated [7403 cfu/cm(2); 95% confidence interval (CI): 6349-8457; for 30 towels sampled], encouraged by inappropriate storage in airtight plastic bags (4437 cfu/cm(2); CI: 3125-5750) compared with storage in porous canvas bags (166 cfu/cm(2); CI: 76-256; P < 0.001). Interventions introduced included revision of laundry practices, transport and storage of hospital linen and towels; bleach-based environmental cleaning; and upgrading of ventilation systems throughout the hospital. Clinical case numbers returned to baseline levels within three months, only to rise again following relaxation of laundry practices. Construction work beside this Singapore hospital encouraged heavy contamination of air and environment with Bacillus spp., assumed to be responsible for the outbreak described. Failure to maintain revised laundry practices allowed resurgence of clinical cases, particularly among immunocompromised patients. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Contamination control requirements implementation for the James Webb Space Telescope (JWST), part 2: spacecraft, sunshield, observatory, and launch

NASA Astrophysics Data System (ADS)

Wooldridge, Eve M.; Schweiss, Andrea; Henderson-Nelson, Kelly; Woronowicz, Michael; Patel, Jignasha; Macias, Matthew; McGregor, R. Daniel; Farmer, Greg; Schmeitzky, Olivier; Jensen, Peter; Rumler, Peter; Romero, Beatriz; Breton, Jacques

2014-09-01

This paper will continue from Part 1 of JWST contamination control implementation. In addition to optics, instruments, and thermal vacuum testing, JWST also requires contamination control for a spacecraft that must be vented carefully in order to maintain solar array and thermal radiator thermal properties; a tennis court-sized sunshield made with 1-2 mil Kapton™ layers that must be manufactured and maintained clean; an observatory that must be integrated, stowed and transported to South America; and a rocket that typically launches commercial payloads without contamination sensitivity. An overview of plans developed to implement contamination control for the JWST spacecraft, sunshield, observatory and launch vehicle will be presented.

Recommended Practices to Improve Nurse Tank Safety: Phase II

DOT National Transportation Integrated Search

2013-12-01

This project addressed four topics: Pinhole leaks in nurse tanks were studied by radiography, serial milling, and side-angle ultrasound. These measurements indicated that welding surfaces contaminated by water, mill scale, rust, or other contamin...

Groundwater Flow Through a Constructed Treatment Wetland

DTIC Science & Technology

2003-03-01

the treatment wetland is to biodegrade perchloroethylene, which is present in the groundwater as a contaminant. Contaminated water enters the...characterizing groundwater flow through a constructed treatment wetland, one can visualize the flow paths of water through various types of soil. With...flowing groundwater and are now appearing in drinking water wells. Since contamination originated from government practices at many of these sites

Effect of fecal contamination and cross-contamination on numbers of coliform, Escherichia coli, Campylobacter, and Salmonella on immersion-chilled broiler carcasses.

PubMed

Smith, D P; Cason, J A; Berrang, M E

2005-07-01

The effect of prechill fecal contamination on numbers of bacteria on immersion-chilled carcasses was tested in each of three replicate trials. For each trial, 16 eviscerated broiler carcasses were split into 32 halves and assigned to one of two groups. Cecal contents (0.1 g inoculated with Campylobacter and nalidixic acid-resistant Salmonella) were applied to each of eight halves in one group (direct contamination) that were placed into one paddle chiller (contaminated), whereas the other paired halves were placed into another chiller (control). From the second group of eight split birds, one of each paired half was placed in the contaminated chiller (to determine cross-contamination) and the other half was placed in the control chiller. Postchill carcass halves were sampled by a 1-min rinse in sterile water, which was collected and cultured. Bacterial counts were reported as log CFU per milliliter of rinsate. There were no significant statistical differences (paired t test, P < 0.05) from direct contamination for coliforms (mean 3.0 log CFU) and Escherichia coli (mean 2.7 log CFU), although Campylobacter numbers significantly increased from control values because of direct contamination (1.5 versus 2.1 log CFU), and the incidence increased from 79 to 100%. There was no significant effect of cross-contamination on coliform (mean 2.9 log CFU) or E. coli (mean 2.6 log CFU) numbers. Nevertheless, Campylobacter levels were significantly higher after exposure to cross-contamination (1.6 versus 2.0 log CFU), and the incidence of this bacterium increased from 75 to 100%. Salmonella-positive halves increased from 0 to 42% postchill because of direct contamination and from 0 to 25% as a result of cross-contamination after chilling. Water samples and surface swabs taken postchill from the contaminated chiller were higher for Campylobacter than those taken from the control chiller. Immersion chilling equilibrated bacterial numbers between contaminated and control halves subjected to either direct contamination or cross-contamination for coliforms and E. coli. Campylobacter numbers, Campylobacter incidence, and Salmonella incidence increased because of both direct contamination and cross-contamination in the chiller. Postchill E. coli numbers did not indicate which carcass halves were contaminated with feces before chilling.

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.

External Contamination Control of Attached Payloads on the International Space Station

NASA Technical Reports Server (NTRS)

Soares, Carlos E.; Mikatarian, Ronald R.; Olsen, Randy L.; Huang, Alvin Y.; Steagall, Courtney A.; Schmidl, William D.; Wright, Bruce D.; Koontz, Steven

2012-01-01

The International Space Station (ISS) is an on-orbit platform for science utilization in low Earth orbit with multiple sites for external payloads with exposure to the natural and induced environments. Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle. This paper describes the external contamination control requirements and integration process for externally mounted payloads on the ISS. The external contamination control requirements are summarized and a description of the integration and verification process is detailed to guide payload developers in the certification process of attached payloads on the vehicle. A description of the required data certification deliverables covers the characterization of contamination sources. Such characterization includes identification, usage and operational data for each class of contamination source. Classes of external contamination sources covered are vacuum exposed materials, sources of leakage, vacuum venting and thrusters. ISS system level analyses are conducted by the ISS Space Environments Team to certify compliance with external contamination control requirements. This paper also addresses the ISS induced contamination environment at attached payload sites, both at the requirements level as well as measurements made on ISS.

Diazinon reduction and partitioning between water, sediment and vegetation in stormwater runoff mitigation through rice fields.

PubMed

Moore, Matthew T; Kröger, Robert; Cooper, Charles M; Cullum, Robert F; Smith, Sammie; Locke, Martin A

2009-11-01

Contamination of surface waters by pesticides is a concern in the United States and around the world. Innovative mitigation strategies are needed to remediate this potential environmental contaminant. One potential solution is to divert pesticide-laden drainage or surface water through agricultural rice fields. With a hydroperiod, hydrosoil and hydrophyte (rice), these systems serve essentially as a type of constructed wetland. In both summer and fall experiments, diazinon-amended water was diverted through two rice ponds at the University of Mississippi Field Station. Likewise, a non-vegetated control pond was amended with diazinon-laden water. Water, sediment and plant samples were taken spatially and temporally to determine the distribution of diazinon within systems. Outflow diazinon concentrations decreased significantly (P < 0.05) from inflow in both vegetated ponds for both preharvest and post-harvest experiments. Although sorption to rice plants was minimal in the overall mass distribution of diazinon (1-3%), temporal data indicated that diazinon concentrations reached the outflow sediment of the non-vegetated control twice as fast as in either vegetated (rice) system. In both vegetated systems, sediment diazinon concentrations decreased (77 and 100%) from inflow to outflow, while a decrease of <2% was noted in the non-vegetated control. Diversion of pesticide-contaminated water through rice fields demonstrated potential as a low-cost, environmentally efficient mitigation practice. Studies on these systems are continuing to evaluate the optimal chemical retention time for rice field mitigation, as well as diazinon transfer to rice grain seeds that may be used as a food source.

Enclosure design for flock-level, chronic exposure of birds to air contaminant mixtures.

PubMed

North, Michelle A; Kinniburgh, David W; Smits, Judit E G

2018-05-01

The objective of this study was to design an enclosure suitable for studying the ecotoxicological effects of vehicle emissions on groups of wild birds without compromising welfare. Two, adjacent enclosures sheltered from sunlight, wind and rain, were bird-proofed and wrapped with thick polyethylene sheeting. Emissions were directed into the treatment enclosure from the exhaust of a light-duty gasoline truck, using flexible, heat-proof pipe, with joins sealed to prevent leakage. During active exposure, the engine was idled for 5 h/day, 6 days/week for 4 weeks. Fans maintained positive pressure (controls) and negative pressure (treatment), preventing cross-contamination of enclosures and protecting investigators. Four sets of passive, badge-type samplers were distributed across each enclosure, measuring nitrogen dioxide, sulfur dioxide and volatile organic compounds (NO 2 , SO 2 and VOCs, respectively), and were complemented by active monitors measuring VOCs and particulate matter (2.5 µm diameter, PM 2.5 ). We found that the concentrations of NO 2 , SO 2 and PM 2.5 were not different between treatment and control enclosures. Volatile organic compounds (e.g. benzene, toluene, ethylbenzene and xylenes) were approximately six times higher in the treatment enclosure than control (13.23 and 2.13 µg m -1 , respectively). In conclusion, this represents a successful, practical design for studying the effects of sub-chronic to chronic exposure to realistic mixtures of vehicle exhaust contaminants, in groups of birds. Recommended modifications for future research include a chassis dynamometer (vehicle treadmill), to better replicate driving conditions including acceleration and deceleration.

Identification of beer spoilage microorganisms using the MALDI Biotyper platform.

PubMed

Turvey, Michelle Elizabeth; Weiland, Florian; Meneses, Jon; Sterenberg, Nick; Hoffmann, Peter

2016-03-01

Beer spoilage microorganisms present a major risk for the brewing industry and can lead to cost-intensive recall of contaminated products and damage to brand reputation. The applicability of molecular profiling using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in combination with Biotyper software was investigated for the identification of beer spoilage microorganisms from routine brewery quality control samples. Reference mass spectrum profiles for three of the most common bacterial beer spoilage microorganisms (Lactobacillus lindneri, Lactobacillus brevis and Pediococcus damnosus), four commercially available brewing yeast strains (top- and bottom-fermenting) and Dekkera/Brettanomyces bruxellensis wild yeast were established, incorporated into the Biotyper reference library and validated by successful identification after inoculation into beer. Each bacterial species could be accurately identified and distinguished from one another and from over 5600 other microorganisms present in the Biotyper database. In addition, wild yeast contaminations were rapidly detected and distinguished from top- and bottom-fermenting brewing strains. The applicability and integration of mass spectrometry profiling using the Biotyper platform into existing brewery quality assurance practices within industry were assessed by analysing routine microbiology control samples from a local brewery, where contaminating microorganisms could be reliably identified. Brewery-isolated microorganisms not present in the Biotyper database were further analysed for identification using LC-MS/MS methods. This renders the Biotyper platform a promising candidate for biological quality control testing within the brewing industry as a more rapid, high-throughput and cost-effective technology that can be tailored for the detection of brewery-specific spoilage organisms from the local environment.

Impact of intensive horticulture practices on groundwater content of nitrates, sodium, potassium, and pesticides.

PubMed

Melo, Armindo; Pinto, Edgar; Aguiar, Ana; Mansilha, Catarina; Pinho, Olívia; Ferreira, Isabel M P L V O

2012-07-01

A monitoring program of nitrate, nitrite, potassium, sodium, and pesticides was carried out in water samples from an intensive horticulture area in a vulnerable zone from north of Portugal. Eight collecting points were selected and water-analyzed in five sampling campaigns, during 1 year. Chemometric techniques, such as cluster analysis, principal component analysis (PCA), and discriminant analysis, were used in order to understand the impact of intensive horticulture practices on dug and drilled wells groundwater and to study variations in the hydrochemistry of groundwater. PCA performed on pesticide data matrix yielded seven significant PCs explaining 77.67% of the data variance. Although PCA rendered considerable data reduction, it could not clearly group and distinguish the sample types. However, a visible differentiation between the water samples was obtained. Cluster and discriminant analysis grouped the eight collecting points into three clusters of similar characteristics pertaining to water contamination, indicating that it is necessary to improve the use of water, fertilizers, and pesticides. Inorganic fertilizers such as potassium nitrate were suspected to be the most important factors for nitrate contamination since highly significant Pearson correlation (r = 0.691, P < 0.01) was obtained between groundwater nitrate and potassium contents. Water from dug wells is especially prone to contamination from the grower and their closer neighbor's practices. Water from drilled wells is also contaminated from distant practices.

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.

A study of blood contamination of Siqveland matrix bands.

PubMed

Lowe, A H; Bagg, J; Burke, F J T; MacKenzie, D; McHugh, S

2002-01-12

AIMS To use a sensitive forensic test to measure blood contamination of used Siqveland matrix bands following routine cleaning and sterilisation procedures in general dental practice. Sixteen general dental practices in the West of Scotland participated. Details of instrument cleaning procedures were recorded for each practice. A total of 133 Siqveland matrix bands were recovered following cleaning and sterilisation and were examined for residual blood contamination by the Kastle-Meyer test, a well-recognised forensic technique. Ultrasonic baths were used for the cleaning of 62 (47%) bands and retainers and the remainder (53%) were hand scrubbed prior to autoclaving. Overall, 21% of the matrix bands and 19% of the retainers gave a positive Kastle-Meyer test, indicative of residual blood contamination, following cleaning and sterilisation. In relation to cleaning method, 34% of hand-scrubbed bands and 32% of hand-scrubbed retainers were positive for residual blood by the Kastle-Meyer test compared with 6% and 3% respectively of ultrasonically cleaned bands and retainers (P < 0.001). If Siqveland matrix bands are re-processed in the assembled state, then adequate pre-sterilisation cleaning cannot be achieved reliably. Ultrasonic baths are significantly more effective than hand cleaning for these items of equipment.

Brownfields to green fields: Realising wider benefits from practical contaminant phytomanagement strategies.

PubMed

Cundy, A B; Bardos, R P; Puschenreiter, M; Mench, M; Bert, V; Friesl-Hanl, W; Müller, I; Li, X N; Weyens, N; Witters, N; Vangronsveld, J

2016-12-15

Gentle remediation options (GROs) are risk management strategies or technologies involving plant (phyto-), fungi (myco-), and/or bacteria-based methods that result in a net gain (or at least no gross reduction) in soil function as well as effective risk management. GRO strategies can be customised along contaminant linkages, and can generate a range of wider economic, environmental and societal benefits in contaminated land management (and in brownfields management more widely). The application of GROs as practical on-site remedial solutions is still limited however, particularly in Europe and at trace element (typically metal and metalloid) contaminated sites. This paper discusses challenges to the practical adoption of GROs in contaminated land management, and outlines the decision support tools and best practice guidance developed in the European Commission FP7-funded GREENLAND project aimed at overcoming these challenges. The GREENLAND guidance promotes a refocus from phytoremediation to wider GROs- or phyto-management based approaches which place realisation of wider benefits at the core of site design, and where gentle remediation technologies can be applied as part of integrated, mixed, site risk management solutions or as part of "holding strategies" for vacant sites. The combination of GROs with renewables, both in terms of biomass generation but also with green technologies such as wind and solar power, can provide a range of economic and other benefits and can potentially support the return of low-level contaminated sites to productive usage, while combining GROs with urban design and landscape architecture, and integrating GRO strategies with sustainable urban drainage systems and community gardens/parkland (particularly for health and leisure benefits), has large potential for triggering GRO application and in realising wider benefits in urban and suburban systems. Quantifying these wider benefits and value (above standard economic returns) will be important in leveraging funding for GRO application and soft site end-use more widely at vacant or underutilized sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

Retrograde contamination and practical handling of urine-meters: a comparison of three systems for the measurement of hourly diuresis in an experimental bladder-drainage model and in clinical use.

PubMed

Rasmussen, A; Frimodt-Møller, N; Espersen, F; Roed, M; Frimodt-Møller, C

1996-08-01

To compare three different urine metering systems for their ability to prevent retrograde contamination in an in vitro model of a closed urinary drainage system and for qualities important to their practical handling in a clinical setting. Using three urine-meters (the Braun Ureofix 511, the Kendall Curity 4000 and the Unoplast Unometer 500) the in vitro model was constantly flushed with a solution of Mueller-Hinton broth diluted with saline. On the first day, the urine collecting bag was inoculated with 10(8) cells of Pseudomonas aeruginosa. The system was operated for 12 days with daily sampling of the model bladder to detect any contamination. After 12 days the experiment was stopped and sampling performed at various locations, including the urine-meter and the tubing. Nine of each type of urine-meter were tested, i.e. three in three different experiments. In the clinical study, 45 patients were randomized to each of the three urine-meters and the nurses attending them were asked to complete a questionnaire on the practical handling of the urine-meters. When the urine-meters was omitted from the model system, the 'bladder' became contaminated with the test bacteria within 3 days. None of the nine Unometer 500 systems became contaminated, compared with four of each of the other two systems (P < 0.05). In clinical use, the Unometer 500 and Ureofix 511 were easier to suspend and empty than was the Curity 4000. The Unometer 500 was significantly easier to handle when the collecting bag was emptied. Urine-meters can prevent retrograde contamination in a closed bladder-drainage model, but the degree of prevention depends upon the type of urine-meter. In daily practice, there were differences in the ease of suspension of the systems and in the emptying of the urine-meter and collecting bag.

Environmental Assessment for Selection and Operation of the Proposed Field Research Centers for the Natural and Accelerated Bioremediation Research (NABIR) Program

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

N /A

2000-04-18

The US Department of Energy (DOE) Office of Biological and Environmental Research (OBER), within the Office of Science (SC), proposes to add a Field Research Center (FRC) component to the existing Natural and Accelerated Bioremediation Research (NABIR) Program. The NABIR Program is a ten-year fundamental research program designed to increase the understanding of fundamental biogeochemical processes that would allow the use of bioremediation approaches for cleaning up DOE's contaminated legacy waste sites. An FRC would be integrated with the existing and future laboratory and field research and would provide a means of examining the fundamental biogeochemical processes that influence bioremediationmore » under controlled small-scale field conditions. The NABIR Program would continue to perform fundamental research that might lead to promising bioremediation technologies that could be demonstrated by other means in the future. For over 50 years, DOE and its predecessor agencies have been responsible for the research, design, and production of nuclear weapons, as well as other energy-related research and development efforts. DOE's weapons production and research activities generated hazardous, mixed, and radioactive waste products. Past disposal practices have led to the contamination of soils, sediments, and groundwater with complex and exotic mixtures of compounds. This contamination and its associated costs and risks represents a major concern to DOE and the public. The high costs, long duration, and technical challenges associated with remediating the subsurface contamination at DOE sites present a significant need for fundamental research in the biological, chemical, and physical sciences that will contribute to new and cost-effective solutions. One possible low-cost approach for remediating the subsurface contamination of DOE sites is through the use of a technology known as bioremediation. Bioremediation has been defined as the use of microorganisms to biodegrade or biotransform hazardous organic contaminants to environmentally safe levels in soils, subsurface materials, water, sludges, and residues.. While bioremediation technology is promising, DOE managers and non-DOE scientists have recognized that the fundamental scientific information needed to develop effective bioremediation technologies for cleanup of the legacy waste sites is lacking in many cases. DOE believes that field-based research is needed to realize the full potential of bioremediation. The Department of Energy faces a unique set of challenges associated with cleaning up waste at its former weapons production and research sites. These sites contain complex mixtures of contaminants in the subsurface, including radioactive compounds. In many cases, the fundamental field-based scientific information needed to develop safe and effective remediation and cleanup technologies is lacking. DOE needs fundamental research on the use of microorganisms and their products to assist DOE in the decontamination and cleanup of its legacy waste sites. The existing NABIR program to-date has focused on fundamental scientific research in the laboratory. Because subsurface hydrologic and geologic conditions at contaminated DOE sites cannot easily be duplicated in a laboratory, however, the DOE needs a field component to permit existing and future laboratory research results to be field-tested on a small scale in a controlled outdoor setting. Such field-testing needs to be conducted under actual legacy waste field conditions representative of those that DOE is most in need of remediating. Ideally, these field conditions should be as representative as practicable of the types of subsurface contamination conditions that resulted from legacy wastes from the nuclear weapons program activities. They should also be representative of the types of hydrologic and geologic conditions that exist across the DOE complex.« less

Correlation of Trace Contaminants to Wastewater Management Practices in Small Watersheds

EPA Science Inventory

Ten low-order streams draining headwatersheds were evaluated over one year for the presence of ten organic contaminants including steroidal hormones, the antibiotic sulfamethoxazole, the antimicrobials triclosan and triclocarban, and the artificial sweetener sucralose. The wastew...

A Best Practices Guide to Talking to your Customers about Chronic Contaminants in Drinking Water

EPA Pesticide Factsheets

This fact sheet will help you understand the importance of communicating with the public about chronic contaminants - both regulated and unregulated. It also describes effective strategies for getting your message out.

A Best Practices Guide for Talking to your Customers about Chronic Contaminants in Drinking Water

EPA Pesticide Factsheets

This fact sheet helps one to understand the importance of communicating with the public about chronic contaminants – both regulated and unregulated. It also describes effective strategies for getting your message out.

Microbiological Safety and Food Handling Practices of Seed Sprout Products in the Australian State of Victoria.

PubMed

Symes, Sally; Goldsmith, Paul; Haines, Heather

2015-07-01

Seed sprouts have been implicated as vehicles for numerous foodborne outbreaks worldwide. Seed sprouts pose a unique food safety concern because of the ease of microbiological seed contamination, the inherent ability of the sprouting process to support microbial growth, and their consumption either raw or lightly cooked. To examine seed sprout safety in the Australian state of Victoria, a survey was conducted to detect specific microbes in seed sprout samples and to investigate food handling practices relating to seed sprouts. A total of 298 seed sprout samples were collected from across 33 local council areas. Escherichia coli was detected in 14.8%, Listeria spp. in 12.3%, and Listeria monocytogenes in 1.3% of samples analyzed. Salmonella spp. were not detected in any of the samples. A range of seed sprout handling practices were identified as potential food safety issues in some food businesses, including temperature control, washing practices, length of storage, and storage in proximity to unpackaged ready-to-eat potentially hazardous foods.

Prevention of emergency physician migratory contamination in a cluster randomized trial to increase tissue plasminogen activator use in stroke (the INSTINCT trial).

PubMed

Weston, Victoria C; Meurer, William J; Frederiksen, Shirley M; Fox, Allison K; Scott, Phillip A

2014-12-01

Cluster randomized trials (CRTs) are increasingly used to evaluate quality improvement interventions aimed at health care providers. In trials testing emergency department (ED) interventions, migration of emergency physicians (EPs) between hospitals is an important concern, as contamination may affect both internal and external validity. We hypothesized that geographically isolating EDs would prevent migratory contamination in a CRT designed to increase ED delivery of tissue plasminogen activator (tPA) in stroke (the INSTINCT trial). INSTINCT was a prospective, cluster randomized, controlled trial. Twenty-four Michigan community hospitals were randomly selected in matched pairs for study. Contamination was defined at the cluster level, with substantial contamination defined a priori as greater than 10% of EPs affected. Nonadherence, total crossover (contamination+nonadherence), migration distance, and characteristics were determined. Three hundred seven EPs were identified at all sites. Overall, 7 (2.3%) changed study sites. One moved between control sites, leaving 6 (2.0%) total crossovers. Of these, 2 (0.7%) moved from intervention to control (contamination); and 4 (1.3%) moved from control to intervention (nonadherence). Contamination was observed in 2 of 12 control sites, with 17% and 9% contamination of the total site EP workforce at follow-up, respectively. Average migration distance was 42 miles for all EPs moving in the study and 35 miles for EPs moving from intervention to control sites. The mobile nature of EPs should be considered in the design of quality improvement CRTs. Increased reporting of contamination in CRTs is encouraged to clarify thresholds and facilitate CRT design. Copyright © 2014 Elsevier Inc. All rights reserved.

Earth Observing System/Meteorological Satellite (EOS/METSAT). Advanced Microwave Sounding Unit-A (AMSU-A) Contamination Control Plan

NASA Technical Reports Server (NTRS)

Fay, M.

1998-01-01

This Contamination Control Plan is submitted in response the Contract Document requirements List (CDRL) 007 under contract NAS5-32314 for the Earth Observing System (EOS) Advanced Microwave Sounding Unit A (AMSU-A). In response to the CDRL instructions, this document defines the level of cleanliness and methods/procedures to be followed to achieve adequate cleanliness/contamination control, and defines the required approach to maintain cleanliness/contamination control through shipping, observatory integration, test, and flight. This plan is also applicable to the Meteorological Satellite (METSAT) except where requirements are identified as EOS-specific. This plan is based on two key factors: a. The EOS/METSAT AMSU-A Instruments are not highly contamination sensitive. b. Potential contamination of other EOS Instruments is a key concern as addressed in Section 9/0 of the Performance Assurance Requirements for EOS/METSAT Integrated Programs AMSU-A Instrument (MR) (NASA Specification S-480-79).

Comparison of hand hygiene procedures for removing Bacillus cereus spores.

PubMed

Sasahara, Teppei; Hayashi, Shunji; Hosoda, Kouichi; Morisawa, Yuji; Hirai, Yoshikazu

2014-01-01

Bacillus cereus is a spore-forming bacterium. B. cereus occasionally causes nosocomial infections, in which hand contamination with the spores plays an important role. Therefore, hand hygiene is the most important practice for controlling nosocomial B. cereus infections. This study aimed to determine the appropriate hand hygiene procedure for removing B. cereus spores. Thirty volunteers' hands were experimentally contaminated with B. cereus spores, after which they performed 6 different hand hygiene procedures. We compared the efficacy of the procedures in removing the spores from hands. The alcohol-based hand-rubbing procedures scarcely removed them. The soap washing procedures reduced the number of spores by more than 2 log10. Extending the washing time increased the spore-removing efficacy of the washing procedures. There was no significant difference in efficacy between the use of plain soap and antiseptic soap. Handwashing with soap is appropriate for removing B. cereus spores from hands. Alcohol-based hand-rubbing is not effective.

Alternatives to Antibiotics in Semen Extenders: A Review

PubMed Central

Morrell, Jane M.; Wallgren, Margareta

2014-01-01

Antibiotics are added to semen extenders to be used for artificial insemination (AI) in livestock breeding to control bacterial contamination in semen arising during collection and processing. The antibiotics to be added and their concentrations for semen for international trade are specified by government directives. Since the animal production industry uses large quantities of semen for artificial insemination, large amounts of antibiotics are currently used in semen extenders. Possible alternatives to antibiotics are discussed, including physical removal of the bacteria during semen processing, as well as the development of novel antimicrobials. Colloid centrifugation, particularly Single Layer Centrifugation, when carried out with a strict aseptic technique, offers a feasible method for reducing bacterial contamination in semen and is a practical method for semen processing laboratories to adopt. However, none of these alternatives to antibiotics should replace strict attention to hygiene during semen collection and handling. PMID:25517429

Effects of natural and human factors on groundwater quality of basin-fill aquifers in the southwestern United States-conceptual models for selected contaminants

USGS Publications Warehouse

Bexfield, Laura M.; Thiros, Susan A.; Anning, David W.; Huntington, Jena M.; McKinney, Tim S.

2011-01-01

As part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program, the Southwest Principal Aquifers (SWPA) study is building a better understanding of the factors that affect water quality in basin-fill aquifers in the Southwestern United States. The SWPA study area includes four principal aquifers of the United States: the Basin and Range basin-fill aquifers in California, Nevada, Utah, and Arizona; the Rio Grande aquifer system in New Mexico and Colorado; and the California Coastal Basin and Central Valley aquifer systems in California. Similarities in the hydrogeology, land- and water-use practices, and water-quality issues for alluvial basins within the study area allow for regional analysis through synthesis of the baseline knowledge of groundwater-quality conditions in basins previously studied by the NAWQA Program. Resulting improvements in the understanding of the sources, movement, and fate of contaminants are assisting in the development of tools used to assess aquifer susceptibility and vulnerability.This report synthesizes previously published information about the groundwater systems and water quality of 15 information-rich basin-fill aquifers (SWPA case-study basins) into conceptual models of the primary natural and human factors commonly affecting groundwater quality with respect to selected contaminants, thereby helping to build a regional understanding of the susceptibility and vulnerability of basin-fill aquifers to those contaminants. Four relatively common contaminants (dissolved solids, nitrate, arsenic, and uranium) and two contaminant classes (volatile organic compounds (VOCs) and pesticide compounds) were investigated for sources and controls affecting their occurrence and distribution above specified levels of concern in groundwater of the case-study basins. Conceptual models of factors that are important to aquifer vulnerability with respect to those contaminants and contaminant classes were subsequently formed. The conceptual models are intended in part to provide a foundation for subsequent development of regional-scale statistical models that relate specific constituent concentrations or occurrence in groundwater to natural and human factors.

Real-time contaminant sensing and control in civil infrastructure systems

NASA Astrophysics Data System (ADS)

Rimer, Sara; Katopodes, Nikolaos

2014-11-01

A laboratory-scale prototype has been designed and implemented to test the feasibility of real-time contaminant sensing and control in civil infrastructure systems. A blower wind tunnel is the basis of the prototype design, with propylene glycol smoke as the ``contaminant.'' A camera sensor and compressed-air vacuum nozzle system is set up at the test section portion of the prototype to visually sense and then control the contaminant; a real-time controller is programmed to read in data from the camera sensor and administer pressure to regulators controlling the compressed air operating the vacuum nozzles. A computational fluid dynamics model is being integrated in with this prototype to inform the correct pressure to supply to the regulators in order to optimally control the contaminant's removal from the prototype. The performance of the prototype has been evaluated against the computational fluid dynamics model and is discussed in this presentation. Furthermore, the initial performance of the sensor-control system implemented in the test section of the prototype is discussed. NSF-CMMI 0856438.

Overview of the International Space Station System Level Trace Contaminant Injection Test

NASA Technical Reports Server (NTRS)

Tatara, James D.; Perry, Jay L.; Franks, Gerald D.

1997-01-01

Trace contaminant control onboard the International Space Station will be accomplished not only by the Trace Contaminant Control Subassembly but also by other Environmental Control and Life Support System subassemblies. These additional removal routes include absorption by humidity condensate in the Temperature and Humidity Control Condensing Heat Exchanger and adsorption by the Carbon Dioxide Removal Assembly. The Trace Contaminant Injection Test, which was performed at NASA's Marshall Space Flight Center, investigated the system-level removal of trace contaminants by the International Space Station Atmosphere Revitalization, and Temperature/Humidity Control Subsystems, (November-December 1997). It is a follow-on to the Integrated Atmosphere Revitalization Test conducted in 1996. An estimate for the magnitude of the assisting role provided by the Carbon Dioxide Removal Assembly and the Temperature and Humidity Control unit was obtained. In addition, data on the purity of Carbon Dioxide Removal Assembly carbon dioxide product were obtained to support Environmental Control and Life Support System Air Revitalization Subsystem loop closure.

Implementation of the TOMS contamination control requirements in the former USSR

NASA Technical Reports Server (NTRS)

Abrams, Eve M.

1992-01-01

The American Total Ozone Mapping Spectrometer (TOMS) was integrated with the Russian Meteor-3 spacecraft and launched on August 15, 1991. Although the TOMS instrument was sensitive to both particulate and molecular contamination, the program for Meteor-3 had not formerly addressed contamination control in ground operations. In order to accommodate the TOMS cleanliness requirements, a contamination control program was successfully established from inception at both the Meteor-3 spacecraft plant near Moscow and at the launch site in Plesetsk.

The Hubble Space Telescope Servicing Mission 3A Contamination Control Program

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.

2000-01-01

After nearly 10 years on-orbit, the Hubble Space Telescope (HST) external thermal control materials and paint have degraded due to exposure to the low Earth orbit environment. This presented a potentially large on-orbit contamination source (particles and/or debris). Contamination mitigation techniques were developed to augment existing on-orbit servicing contamination controls. They encompassed mission management, crew training, and crew aids and tools. These techniques were successfully employed during the HST Servicing Mission 3A, December 1999.

The trade network in the dairy industry and its implication for the spread of contamination.

PubMed

Pinior, B; Konschake, M; Platz, U; Thiele, H D; Petersen, B; Conraths, F J; Selhorst, T

2012-11-01

In case of an outbreak of a foodborne disease, administrative decisions in the context of crisis management are only efficient if they follow standard practices and are specifically adapted to the outbreak situation in a timely manner. These goals are hard to achieve. The complexity of national and global trade structures obscures a clear view of trade flows and, consequently, it is often impossible to unravel complex trade links quickly. Furthermore, increasing public concerns about possible health hazards caused by global trade put additional pressure on decision makers. The aim of this paper was to unveil the specific trade structures of the German milk supply chain, to highlight how these structures could affect the spatial spread of a hypothetical contaminant, and to quantify the risk of the contaminant reaching the consumer. To achieve this goal, the vertical and horizontal trade links between milk producers, dairies, and consumers were taken into account. The horizontal flow of milk between dairies (inter-dairy trade), which is intended to compensate a temporary over- or undersupply of milk, is of special importance in this respect. We hypothesized that the extent of inter-dairy trade would significantly influence the spatial spread of contaminated milk and the contamination risk. This hypothesis was tested using a computer simulation model that predicts the hypothetical spread of a contaminant via trade of milk. The model parameters were estimated using trade data collected in 2004 and 2010. The results of our study indicate that inter-dairy trade significantly influenced the contamination risk. Compared with a scenario with no inter-dairy trade, the risk that contaminated milk will reach the consumer was up to 4 times higher, even with moderate inter-dairy trade. The contamination risk depended on the extent of inter-dairy trade in a nonlinear way and reached its maximum asymptotically when inter-dairy trade increased. The contamination risk exhibited considerable spatial variation, which could be utilized to implement more accurate food control interventions in times of crisis caused by a foodborne disease. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Pathogen and biological contamination management in plant tissue culture: phytopathogens, vitro pathogens, and vitro pests.

PubMed

Cassells, Alan C

2012-01-01

The ability to establish and grow plant cell, organ, and tissue cultures has been widely exploited for basic and applied research, and for the commercial production of plants (micro-propagation). Regardless of whether the application is for research or commerce, it is essential that the cultures be established in vitro free of biological contamination and be maintained as aseptic cultures during manipulation, growth, and storage. The risks from microbial contamination are spurious experimental results due to the effects of latent contaminants or losses of valuable experimental or commercial cultures. Much of the emphasis in culture contamination management historically focussed on the elimination of phytopathogens and the maintenance of cultures free from laboratory contamination by environmental bacteria, fungi (collectively referred to as "vitro pathogens", i.e. pathogens or environmental micro-organisms which cause culture losses), and micro-arthropods ("vitro pests"). Microbial contamination of plant tissue cultures is due to the high nutrient availability in the almost universally used Murashige and Skoog (Physiol Plant 15:473-497, 1962) basal medium or variants of it. In recent years, it has been shown that many plants, especially perennials, are at least locally endophytically colonized intercellularly by bacteria. The latter, and intracellular pathogenic bacteria and viruses/viroids, may pass latently into culture and be spread horizontally and vertically in cultures. Growth of some potentially cultivable endophytes may be suppressed by the high salt and sugar content of the Murashige and Skoog basal medium and suboptimal temperatures for their growth in plant tissue growth rooms. The management of contamination in tissue culture involves three stages: disease screening (syn. disease indexing) of the stock plants with disease and endophyte elimination where detected; establishment and pathogen and contaminant screening of established initial cultures; observation, random sampling, and culture screening for micro-organism in multiplication and stored cultures. The increasing accessibility of both broad-spectrum and specific molecular diagnostics has resulted in advances in multiple pathogen and latent contaminant detection. The hazard analysis critical control point management strategy for tissue culture laboratories is underpinned by staff training in aseptic technique and good laboratory practice.

Contaminant concentration versus flow velocity: drivers of biodegradation and microbial growth in groundwater model systems.

PubMed

Grösbacher, Michael; Eckert, Dominik; Cirpka, Olaf A; Griebler, Christian

2018-06-01

Aromatic hydrocarbons belong to the most abundant contaminants in groundwater systems. They can serve as carbon and energy source for a multitude of indigenous microorganisms. Predictions of contaminant biodegradation and microbial growth in contaminated aquifers are often vague because the parameters of microbial activity in the mathematical models used for predictions are typically derived from batch experiments, which don't represent conditions in the field. In order to improve our understanding of key drivers of natural attenuation and the accuracy of predictive models, we conducted comparative experiments in batch and sediment flow-through systems with varying concentrations of contaminant in the inflow and flow velocities applying the aerobic Pseudomonas putida strain F1 and the denitrifying Aromatoleum aromaticum strain EbN1. We followed toluene degradation and bacterial growth by measuring toluene and oxygen concentrations and by direct cell counts. In the sediment columns, the total amount of toluene degraded by P. putida F1 increased with increasing source concentration and flow velocity, while toluene removal efficiency gradually decreased. Results point at mass transfer limitation being an important process controlling toluene biodegradation that cannot be assessed with batch experiments. We also observed a decrease in the maximum specific growth rate with increasing source concentration and flow velocity. At low toluene concentrations, the efficiencies in carbon assimilation within the flow-through systems exceeded those in the batch systems. In all column experiments the number of attached cells plateaued after an initial growth phase indicating a specific "carrying capacity" depending on contaminant concentration and flow velocity. Moreover, in all cases, cells attached to the sediment dominated over those in suspension, and toluene degradation was performed practically by attached cells only. The observed effects of varying contaminant inflow concentration and flow velocity on biodegradation could be captured by a reactive-transport model. By monitoring both attached and suspended cells we could quantify the release of new-grown cells from the sediments to the mobile aqueous phase. Studying flow velocity and contaminant concentrations as key drivers of contaminant transformation in sediment flow-through microcosms improves our system understanding and eventually the prediction of microbial biodegradation at contaminated sites.

Risk-based remediation of polluted sites: A critical perspective.

PubMed

Kuppusamy, Saranya; Venkateswarlu, Kadiyala; Megharaj, Mallavarapu; Mayilswami, Srinithi; Lee, Yong Bok

2017-11-01

Sites contaminated with chemical pollutants represent a growing challenge, and remediation of such lands is of international concern. Risk-based land management (RBLM) is an emerging approach that integrates risk assessment practices with more traditional site-specific investigations and remediation activities. Developing countries are yet to adopt RBLM strategies for remediation. RBLM is considered to be practical, scientifically defensible and cost-efficient. However, it is inherently limited by: firstly, the accuracy of risk assessment models used; secondly, ramifications of the fact that they are more likely to leave contamination in place; and thirdly, uncertainties involved and having to consider the total concentrations of all contaminants in soils that overestimate the potential risks from exposure to the contaminants. Consideration of contaminant bioavailability as the underlying basis for risk assessment and setting remediation goals of those contaminated lands that pose a risk to environmental and human health may lead to the development of a more sophisticated risk-based approach. However, employing the bioavailability concept in RBLM has not been extensively studied and/or legalized. This review highlights the extent of global land contamination, and the concept of risk-based assessment and management of contaminated sites including its advantages and disadvantages. Furthermore, the concept of bioavailability-based RBLM strategy has been proposed, and the challenges of RBLM and the priority areas for future research are summarized. Thus, the present review may help achieve a better understanding and successful implementation of a sustainable bioavailability-based RBLM strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quality Assurance and Quality Control, Part 2.

PubMed

Akers, Michael J

2015-01-01

The tragedy surrounding the New England Compounding Center and contaminated steroid syringe preparations clearly points out what can happen if quality-assurance and quality-control procedures are not strictly practiced in the compounding of sterile preparations. This article is part 2 of a two-part article on requirements to comply with United States Pharmacopeia general chapters <797> and <1163> with respect to quality assurance of compounded sterile preparations. Part 1 covered documentation requirements, inspection procedures, compounding accuracy checks, and part of a discussion on bacterial endotoxin testing. Part 2 covers sterility testing, the completion from part 1 on bacterial endotoxin testing, a brief dicussion of United States Pharmacopeia <1163>, and advances in pharmaceutical quality systems.

Radiological health risk evaluation of radium contaminated land: a real life implementation.

PubMed

Paridaens, J

2005-01-01

A plot of land, currently used for dairy farming, has been contaminated over the years with radium due to the operation of one of the world's largest radium production plants. Within the framework of a global remediation approach for the plant surroundings, the land owner needed advice for a future destination of the land. Therefore, the radium contamination was accurately mapped, and on the basis of its severity a practically feasible subdivision of the land into four plots was proposed. For all four plots, the radiological risk was evaluated for the current type of land use and for possible alternative types. Hence a clear and useable advice could be formulated to the authorities reconciling public health, economic and practical issues.

Food safety

MedlinePlus

... conditions and practices that preserve the quality of food. These practices prevent contamination and foodborne illnesses. ... not handled properly. Improperly cooking, preparing, or storing ... Properly handling, storing, and preparing food greatly reduces ...

Survival of Escherichia coli on strawberries grown under greenhouse conditions.

PubMed

Shaw, Angela Laury; Svoboda, Amanda; Jie, Beatrice; Nonnecke, Gail; Mendonca, Aubrey

2015-04-01

Strawberries are soft fruit that are not recommended to have a post-harvest wash due to quality concerns. Escherichia coli O157:H7 has been linked to outbreaks with strawberries but little is known about the survival of E. coli during the growth cycle of strawberries. The survival of E. coli on strawberry plants during growing under greenhouses conditions was evaluated. Soil, leaves, and strawberries (if present) were artificially contaminated with an E. coli surrogate either at the time of planting, first runner removal (4 wk), second runner removal (8 wk), or one week prior to harvest. At harvest E. coli was recovered from the leaves, soil, and strawberries regardless of the contamination time. Time of contamination influenced (P < 0.05) numbers of viable E. coli on the plant. The highest survival of E. coli (P < 0.0001) was detected in soil that was contaminated at planting (4.27 log10 CFU g soil(-1)), whereas, the survival of E. coli was maximal at later contamination times (8 wk and 1 wk prior to harvest) for the leaves (4.40 and 4.68 log10 CFU g leaves(-1)) and strawberries (3.37 and 3.53 log10 CFU strawberry(-1)). Cross contamination from leaves to fruit was observed during this study, with the presence of E. coli on strawberries which had not been present at the time of contamination. These results indicate that good agricultural best practices to avoid contamination are necessary to minimize the risk of contamination of these popular fruit with enteric pathogens. Practices should include soil testing prior to harvest and avoiding contamination of the leaves. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Simulation on contamination forecast and control of groundwater in a certain hazardous waste landfill].

PubMed

Ma, Zhi-Fei; An, Da; Jiang, Yong-Hai; Xi, Bei-Dou; Li, Ding-Long; Zhang, Jin-Bao; Yang, Yu

2012-01-01

On the basis of site investigation and data collection of a certain hazardous waste landfill, the groundwater flow and solute transport coupled models were established by applying Visual Modflow software, which was used to conduct a numerical simulation that forecast the transport process of Cr6+ in groundwater and the effects of three control measures (ground-harden, leakage-proof barriers and drainage ditches) of contaminants transport after leachate leakage happened in impermeable layer of the landfill. The results show that the contamination plume of Cr6+ transports with groundwater flow direction, the contamination rang would reach the pool's boundary in 10 years, and the distance of contamination transport is 1 450 m. But the diffusion range of contamination plume would not be obviously expanded between 10 and 20 years. While the ground is hardened, the contamination plume would not reach the pool's boundary in 20 years. When the leakage-proof barrier is set in the bottom of water table aquifer, the concentration of Cr6+ is higher than that the leakage-proof barrier is unset, but the result is just opposite when setting the leakage-proof barrier in the bottom of underlying aquifer. The range of contamination plume is effectively controlled by setting drainage ditches that water discharge is 2 642 m3 x d(-1), which makes the monitoring wells would not be contaminated in 20 years. Moreover, combining the ground-harden with drainage ditches can get the best effect in controlling contaminants diffusion, and meanwhile, the drainage ditches' daily discharge is reduced to 1 878 m3 x d(-1). Therefore, it is suggested that the control measure combining the ground-harden with drainage ditches should apply to prevent contamination diffusion in groundwater when leachate leakage have happened in impermeable layer of the landfill.

Genital region cleansing wipes: Effects on urine culture contamination.

PubMed

Selek, Mehmet Burak; Bektöre, Bayhan; Sezer, Ogün; Kula Atik, Tuğba; Baylan, Orhan; Özyurt, Mustafa

2017-01-30

Urine culture is the gold standard test for revealing the microbial agent causing urinary tract infection (UTI). Culture results are affected by sampling techniques; improper sampling leads to contamination of urine and thus contamination of the culture with urogenital flora. We aimed to evaluate the effect of urogenital cleansing, performed with chlorhexidine-containing genital region cleansing wipes (GRCW) on contamination rates. A total of 2,665 patients with UTI-related complaints and with urine culture requests from various outpatient clinics were enrolled in the study. Of the patients, 1,609 in the experimental group used GRCW before sampling, while 1,046 in the control group did not use any wipes. The contamination rate in the experimental group patients was 7.7%, while it was 15.8% in the control group. Contamination rates were significantly higher in the control group than in the experimental group for both women and men. Contamination rates for children and adults were also significantly lower in the experimental group than in the control group. Our study, conducted in a large population, showed that the use of chlorhexidine-containing cleansing wipes significantly reduced urine culture contamination rates in both genders, in both child and adult age groups. Using GRCW, collection of urine after urogenital area cleansing will decrease the contamination problem.

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.

Prevention of Salmonella cross-contamination in an oilmeal manufacturing plant.

PubMed

Morita, T; Kitazawa, H; Iida, T; Kamata, S

2006-08-01

The mechanisms of Salmonella contamination in an oilmeal plant were investigated and the basic data were collected in order to achieve control of Salmonella in oilmeal. Salmonella was detected in all contamination vectors and environmental factors investigated, namely: operators, processing floor, dust in the air and rodents. In particular, high concentrations of Salmonella were detected on the processing floor of the manufacturing area, which has high oil content. Steam was the most effective disinfection method used for the processing floor, as the effects of heat sterilization and disinfection may work in tandem. In addition, restricting the movement of operators of the production chain remarkably reduced Salmonella contamination, even in areas of otherwise high contamination. Within the oilmeal plant, high Salmonella contamination rates for the processing floor represent the greatest risk of contamination of oilmeal via operators, dust in the air and rodents. Therefore, control of the processing floor is the most important means for reducing the oilmeal contamination rate. Specific Salmonella control methods for oilmeal plants have been established.

Outbreak of Pantoea agglomerans Bloodstream Infections at an Oncology Clinic-Illinois, 2012-2013.

PubMed

Yablon, Brian R; Dantes, Raymund; Tsai, Victoria; Lim, Rachel; Moulton-Meissner, Heather; Arduino, Matthew; Jensen, Bette; Patel, Megan Toth; Vernon, Michael O; Grant-Greene, Yoran; Christiansen, Demian; Conover, Craig; Kallen, Alexander; Guh, Alice Y

2017-03-01

OBJECTIVE To determine the source of a healthcare-associated outbreak of Pantoea agglomerans bloodstream infections. DESIGN Epidemiologic investigation of the outbreak. SETTING Oncology clinic (clinic A). METHODS Cases were defined as Pantoea isolation from blood or catheter tip cultures of clinic A patients during July 2012-May 2013. Clinic A medical charts and laboratory records were reviewed; infection prevention practices and the facility's water system were evaluated. Environmental samples were collected for culture. Clinical and environmental P. agglomerans isolates were compared using pulsed-field gel electrophoresis. RESULTS Twelve cases were identified; median (range) age was 65 (41-78) years. All patients had malignant tumors and had received infusions at clinic A. Deficiencies in parenteral medication preparation and handling were identified (eg, placing infusates near sinks with potential for splash-back contamination). Facility inspection revealed substantial dead-end water piping and inadequate chlorine residual in tap water from multiple sinks, including the pharmacy clean room sink. P. agglomerans was isolated from composite surface swabs of 7 sinks and an ice machine; the pharmacy clean room sink isolate was indistinguishable by pulsed-field gel electrophoresis from 7 of 9 available patient isolates. CONCLUSIONS Exposure of locally prepared infusates to a contaminated pharmacy sink caused the outbreak. Improvements in parenteral medication preparation, including moving chemotherapy preparation offsite, along with terminal sink cleaning and water system remediation ended the outbreak. Greater awareness of recommended medication preparation and handling practices as well as further efforts to better define the contribution of contaminated sinks and plumbing deficiencies to healthcare-associated infections are needed. Infect Control Hosp Epidemiol 2017;38:314-319.

Commencement Bay Nearshore/Tideflats Superfund Site, Tacoma, Washington Remedial Investigations. Evaluation of Alternative Dredging Methods and Equipment, Disposal Methods and Sites, and Site Control and Treatment Practices for Contaminated Sediments.

DTIC Science & Technology

1985-06-01

material may have on ground water and drain- age systems and the possible burial of hazardous materials already existing on the site. The Port of Tacoma is...good resistance to inorganic chemicals; high gas permeability Asphalt- Core layer Of blown asphalt M Flexible enough to conform to Ages rapidly in hot...Tendst to harden on aging ; low polyethylene reacting polyethylene with acids, and alkalis tensile strength; tenoericy to chlorine and sulfur dioxide

Glucosinolate-Containing Seed Meal as a Soil Amendment to Control Plant Pests: 2000-2002

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

Brown, J.; Morra, M. J.

Plants may produce compounds that directly or indirectly affect their biological environment. These compounds fall within a broad category of compounds called allelochemicals, and are exclusive of food that influences growth, health, or behavior of other organisms (Whittaker and Feeney 1971). One reason for interest in allelochemicals is their potential for use in alternative pest management systems. Using plant-produced allelochemicals in agricultural and horticultural practices could minimize synthetic pesticide use, reduce the associated potential for environmental contamination, and contribute to a more sustainable agricultural system.

Design, Qualification, and On Orbit Performance of the CALIPSO Aerosol Lidar Transmitter

NASA Technical Reports Server (NTRS)

Hovis, Floyd E.; Witt, Greg; Sullivan, Edward T.; Le, Khoa; Weimer, Carl; Applegate, Jeff; Luck, William S., Jr.; Verhapen, Ron; Cisewski, Michael S.

2007-01-01

The laser transmitter for the CALIPSO aerosol lidar mission has been operating on orbit as planned since June 2006. This document discusses the optical and laser system design and qualification process that led to this success. Space-qualifiable laser design guidelines included the use of mature laser technologies, the use of alignment sensitive resonator designs, the development and practice of stringent contamination control procedures, the operation of all optical components at appropriately derated levels, and the proper budgeting for the space-qualification of the electronics and software.

On-site monitoring of construction of Terror Lake hydroelectric project, Kodiak, Alaska. Final report

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

Hosking, H.

The report describes the effort by the Fish and Wildlife Service to monitor the construction of the first hydroelectric project built on national wildlife refuge lands under license by the Federal Energy Regulatory Commission. Recommendations are offered for use in planning other projects. Fish and wildlife species of concern included brown bears, Sitka black-tailed deer, mountain goats, raptors (including bald eagles), and several species of salmonid fish. Construction practices relating to erosion control, contaminant management, culvert placement, and siting of project structures are covered.

Optimizing methods and dodging pitfalls in microbiome research.

PubMed

Kim, Dorothy; Hofstaedter, Casey E; Zhao, Chunyu; Mattei, Lisa; Tanes, Ceylan; Clarke, Erik; Lauder, Abigail; Sherrill-Mix, Scott; Chehoud, Christel; Kelsen, Judith; Conrad, Máire; Collman, Ronald G; Baldassano, Robert; Bushman, Frederic D; Bittinger, Kyle

2017-05-05

Research on the human microbiome has yielded numerous insights into health and disease, but also has resulted in a wealth of experimental artifacts. Here, we present suggestions for optimizing experimental design and avoiding known pitfalls, organized in the typical order in which studies are carried out. We first review best practices in experimental design and introduce common confounders such as age, diet, antibiotic use, pet ownership, longitudinal instability, and microbial sharing during cohousing in animal studies. Typically, samples will need to be stored, so we provide data on best practices for several sample types. We then discuss design and analysis of positive and negative controls, which should always be run with experimental samples. We introduce a convenient set of non-biological DNA sequences that can be useful as positive controls for high-volume analysis. Careful analysis of negative and positive controls is particularly important in studies of samples with low microbial biomass, where contamination can comprise most or all of a sample. Lastly, we summarize approaches to enhancing experimental robustness by careful control of multiple comparisons and to comparing discovery and validation cohorts. We hope the experimental tactics summarized here will help researchers in this exciting field advance their studies efficiently while avoiding errors.

Contamination control of the space shuttle Orbiter crew compartment

NASA Technical Reports Server (NTRS)

Bartelson, Donald W.

1986-01-01

Effective contamination control as applied to manned space flight environments is a discipline characterized and controlled by many parameters. An introduction is given to issues involving Orbiter crew compartment contamination control. An effective ground processing contamination control program is an essential building block to a successful shuttle mission. Personnel are required to don cleanroom-grade clothing ensembles before entering the crew compartment and follow cleanroom rules and regulations. Prior to crew compartment entry, materials and equipment must be checked by an orbiter integrity clerk stationed outside the white-room entrance for compliance to program requirements. Analysis and source identification of crew compartment debris studies have been going on for two years. The objective of these studies is to determine and identify particulate generating materials and activities in the crew compartment. Results show a wide spectrum of many different types of materials. When source identification is made, corrective action is implemented to minimize or curtail further contaminate generation.

Public health implications of contamination of Franc CFA (XAF) circulating in Buea (Cameroon) with drug resistant pathogens.

PubMed

Akoachere, Jane-Francis Tatah Kihla; Gaelle, Nana; Dilonga, Henry Meriki; Nkuo-Akenji, Theresa K

2014-01-08

Studies in different parts of the world have implicated money as a vehicle for transmission of pathogens. Such information which is necessary to facilitate infection control strategies is lacking in many sub-Saharan countries including Cameroon. This study analyzed the Franc de la Communauté Financiere d'Afrique (Franc CFA), the currency used in Cameroon and other countries in the Central African sub-region, as a potential vehicle for transmission of pathogenic bacteria and fungi, particularly drug-resistant strains, to generate findings which could create awareness on currency contamination and serve as a guide when formulating health policies on currency. Two hundred and thirteen currency samples representing various denominations of notes and coins randomly collected from diverse sources in Buea, Cameroon were analyzed for bacteria and fungi. The sensitivity of bacterial isolates to antibiotics was tested using the disc diffusion method. The relationship between contamination and physical state, source or denomination of currency was assessed using the χ2 test. All statistics were discussed at 0.05 significance level. Two hundred (93.9%) samples were contaminated with notes (96.6%) showing higher contamination than coins (88.2%). Uncirculated (mint) samples showed no contamination. There was a significant difference (P<0.05) in contamination with respect to currency denomination, physical state and source. All samples from butchers and patients/personnel in hospitals were contaminated. Lower denominations showed significantly higher (P = 0.008) levels of contamination than higher denominations. Dirty currency was more contaminated than clean currency. Nine bacterial species were isolated. Coagulase-negative Staphylococcus (CoNS) (54.9%) and Staphylococcus aureus (20.1%) predominated. Among the fungi detected, Aspergillus sp (17.3%) and Penicillium sp (15.9%) showed higher frequency of occurrence. Bacteria were susceptible (100%) to ceftriaxone, gentamicin, norfloxacin and ofloxacin. Susceptibility to amoxicillin, penicillin, ampicillin, vancomycin and cotrimoxazole was low. Staphylococci were resistant (100%) to vancomycin, penicillin G, and amoxicillin. CoNS in addition showed resistance (100%) to cotrimoxazole. The CFA franc circulating in Buea could serve as a vehicle for transmission of drug resistant pathogenic or potential organisms and contamination could be due to currency usage and handling as mint notes were not contaminated. Hygiene practices during or after handling currency is greatly encouraged to prevent infection.

Potential contaminants in the food chain: identification, prevention and issue management.

PubMed

Scanlan, Francis P

2007-01-01

Contaminants are a vast subject area of food safety and quality. They are generally divided into chemical, microbiological and physical classes and are present in our food chain from raw materials to finished products. They are the subject of international and national legislation that has widened to cover more and more contaminant classes and food categories. In addition, consumers have become increasingly aware of and alarmed by their risks, whether rightly or not. What is the food industry doing to ensure the safety and quality of the products we feed our children? This is a valid question which this article attempts to address from an industrial viewpoint. Chemical food safety is considered a complex field where the risk perception of consumers is often the highest. The effects of chronic or acute exposure to chemical carcinogens may cause disease conditions long after exposure that can be permanently debilitating or even fatal. It is also a moving target, as knowledge about the toxicity and occurrence data of new chemical contaminants continues to be generated. Their identification, prevention and management are challenges to the food industry as a whole. A reminder of the known chemical hazards in the food chain will be presented with an emphasis on the use of early warning to identify potential new contaminants. Early warning is also a means of prevention, anticipating food safety concerns before they become issues to manage. Current best management practices including Hazard Analysis and Critical Control Points relating to the supply chain of baby foods and infant formulae will be developed. Finally, key lessons from a case study on recent contamination issues in baby food products will be presented.

Nebraska's groundwater legacy: Nitrate contamination beneath irrigated cropland

PubMed Central

Exner, Mary E; Hirsh, Aaron J; Spalding, Roy F

2014-01-01

A 31 year record of ∼44,000 nitrate analyses in ∼11,500 irrigation wells was utilized to depict the decadal expansion of groundwater nitrate contamination (N ≥ 10 mg/L) in the irrigated corn-growing areas of eastern and central Nebraska and analyze long-term nitrate concentration trends in 17 management areas (MAs) subject to N fertilizer and budgeting requirements. The 1.3 M contaminated hectares were characterized by irrigation method, soil drainage, and vadose zone thickness and lithology. The areal extent and growth of contaminated groundwater in two predominately sprinkler-irrigated areas was only ∼20% smaller beneath well-drained silt loams with thick clayey-silt unsaturated layers and unsaturated thicknesses >15 m (400,000 ha and 15,000 ha/yr) than beneath well and excessively well-drained soils with very sandy vadose zones (511,000 ha and 18,600 ha/yr). Much slower expansion (3700 ha/yr) occurred in the 220,000 contaminated hectares in the central Platte valley characterized by predominately gravity irrigation on thick, well-drained silt loams above a thin (∼5.3 m), sandy unsaturated zone. The only reversals in long-term concentration trends occurred in two MAs (120,500 ha) within this contaminated area. Concentrations declined 0.14 and 0.20 mg N/L/yr (p < 0.02) to ∼18.3 and 18.8 mg N/L, respectively, during >20 years of management. Average annual concentrations in 10 MAs are increasing (p < 0.05) and indicate that average nitrate concentrations in leachates below the root zone and groundwater concentrations have not yet reached steady state. While management practices likely have slowed increases in groundwater nitrate concentrations, irrigation and nutrient applications must be more effectively controlled to retain nitrate in the root zone. PMID:25558112

Sorption of Pharmaceuticals, Heavy Metals, and Herbicides to Biochar in the Presence of Biosolids.

PubMed

Bair, Daniel A; Mukome, Fungai N D; Popova, Inna E; Ogunyoku, Temitope A; Jefferson, Allie; Wang, Daoyuan; Hafner, Sarah C; Young, Thomas M; Parikh, Sanjai J

2016-11-01

Agricultural practices are increasingly incorporating recycled waste materials, such as biosolids, to provide plant nutrients and enhance soil functions. Although biosolids provide benefits to soil, municipal wastewater treatment plants receive pharmaceuticals and heavy metals that can accumulate in biosolids, and land application of biosolids can transfer these contaminants to the soil. Environmental exposure of these contaminants may adversely affect wildlife, disrupt microbial communities, detrimentally affect human health through long-term exposure, and cause the proliferation of antibiotic-resistant bacteria. This study considers the use of biochar co-amendments as sorbents for contaminants from biosolids. The sorption of pharmaceuticals (ciprofloxacin, triclocarban, triclosan), and heavy metals (Cu, Cd, Ni, Pb) to biochars and biochar-biosolids-soil mixtures was examined. Phenylurea herbicide (monuron, diuron, linuron) sorption was also studied to determine the potential effect of biochar on soil-applied herbicides. A softwood (SW) biochar (510°C) and a walnut shell (WN) biochar (900°C) were used as contrasting biochars to highlight potential differences in biochar reactivity. Kaolinite and activated carbon served as mineral and organic controls. Greater sorption for almost all contaminants was observed with WN biochar over SW biochar. The addition of biosolids decreased sorption of herbicides to SW biochar, whereas there was no observable change with WN biochar. The WN biochar showed potential for reducing agrochemical and contaminant transport but may inhibit the efficacy of soil-applied herbicides. This study provides support for minimizing contaminant mobility from biosolids using biochar as a co-amendment and highlights the importance of tailoring biochars for specific characteristics through feedstock selection and pyrolysis-gasification conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The use of reference materials in quality assurance programmes in food microbiology laboratories.

PubMed

In't Veld, P H

1998-11-24

Nine different reference materials (RMs) for use in food and water microbiology have been developed with the support of the European Commission (EC). The production process of RMs is based on spray drying bacteria suspended in milk. The highly contaminated milk powder (HCMP) obtained is mixed with sterile milk powder to achieve the desired level of contamination and is subsequently filled into gelatine capsules. The HCMP may need to be stabilised by storage for more than a year before a stable RM can be prepared. The HCMP are mixed with sterile milk powder using a pestle and mortar in order to produce homogeneous RMs. For routine use of RMs Shewhart control charts can be produced. Based on log10 transformed counts, control limits are calculated. Rules for the interpretation of results facilitate the detection of out of control situations. Besides RMs there are also CRMs (Certified Reference Materials) that are certified by the EC Community Bureau of Reference (BCR) and are intended for occasional use. Based on the BCR certificate, user tables are produced presenting the 95% confidence limits for the number of capsules likely to be examined in practice. Also power analysis is made to indicate the minimum difference between the certified value and the observed geometric mean value in relation to the number of capsules examined.

COLLECTION OF DESIGN DATA: SITE CHARACTERIZATION FOR PERMEABLE REACTIVE BARRIERS

EPA Science Inventory

Permeable reactive barriers (PRBs) for the restoration of contaminated ground water are no longer innovative. PRBs have evolved from innovative to accepted, standard practice, for the containment and treatment of a variety of contaminants in ground water. Like any remedial tech...

21 CFR 110.10 - Personnel.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD General... contamination of food. The methods for maintaining cleanliness include, but are not limited to: (1) Wearing outer garments suitable to the operation in a manner that protects against the contamination of food...

Beyond hand hygiene: a qualitative study of the everyday work of preventing cross-contamination on hospital wards.

PubMed

Hor, Su-Yin; Hooker, Claire; Iedema, Rick; Wyer, Mary; Gilbert, Gwendolyn L; Jorm, Christine; O'Sullivan, Matthew Vincent Neil

2017-07-01

Hospital-acquired infections are the most common adverse event for inpatients worldwide. Efforts to prevent microbial cross-contamination currently focus on hand hygiene and use of personal protective equipment (PPE), with variable success. Better understanding is needed of infection prevention and control (IPC) in routine clinical practice. We report on an interventionist video-reflexive ethnography study that explored how healthcare workers performed IPC in three wards in two hospitals in New South Wales, Australia: an intensive care unit and two general surgical wards. We conducted 46 semistructured interviews, 24 weeks of fieldwork (observation and videoing) and 22 reflexive sessions with a total of 177 participants (medical, nursing, allied health, clerical and cleaning staff, and medical and nursing students). We performed a postintervention analysis, using a modified grounded theory approach, to account for the range of IPC practices identified by participants. We found that healthcare workers' routine IPC work goes beyond hand hygiene and PPE. It also involves, for instance, the distribution of team members during rounds, the choreography of performing aseptic procedures and moving 'from clean to dirty' when examining patients. We account for these practices as the logistical work of moving bodies and objects across boundaries, especially from contaminated to clean/vulnerable spaces, while restricting the movement of micro-organisms through cleaning, applying barriers and buffers, and trajectory planning. Attention to the logistics of moving people and objects around healthcare spaces, especially into vulnerable areas, allows for a more comprehensive approach to IPC through better contextualisation of hand hygiene and PPE protocols, better identification of transmission risks, and the design and promotion of a wider range of preventive strategies and solutions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Management practices and forage quality affecting the contamination of milk with anaerobic spore-forming bacteria.

PubMed

Zucali, Maddalena; Bava, Luciana; Colombini, Stefania; Brasca, Milena; Decimo, Marilù; Morandi, Stefano; Tamburini, Alberto; Crovetto, G Matteo

2015-04-01

Anaerobic spore-forming bacteria (ASFB) in milk derive from the farm environment, and the use of silages and management practices are the main responsible of milk ASFB contamination. The aim of this study was to evaluate the relationships between feeding, milking routine and cow hygiene and milk and Grana Padano cheese (produced with and without lysozyme) ASFB contamination. The study involved 23 dairy farms. ASFB in corn silage were on average 2.34 ± 0.87 log10 MPN g(-1). For grass, Italian ryegrass and alfalfa, ASFB (log10 MPN g(-1)) were numerically higher for silages (3.22) than hays (2.85). The use of corn silages of high quality (high lactic and acetic acids concentrations) decreased the milk ASFB contamination, whilst the use of herbage silages did not affect it. The presence (>40%) of cows with dirty udders increased the ASFB contamination of milk, while forestripping had a positive effect (-9% ASFB). Ripened Grana Padano had an ASFB count below the analytical limit; Clostridium tyrobutyricum DNA was found only in wheels produced without lysozyme, which also showed late blowing. The factors increasing milk spore contamination were corn silage quality, cow udder hygiene and inadequate milking routine. Late blowing was present only in cheeses without lysozyme. © 2014 Society of Chemical Industry.

Healthcare workers mobile phone usage: A potential risk for viral contamination. Surveillance pilot study.

PubMed

Cavari, Yuval; Kaplan, Or; Zander, Aviva; Hazan, Guy; Shemer-Avni, Yonat; Borer, Abraham

2016-01-01

Mobile phones are commonly used by healthcare workers (HCW) in the working environment, as they allow instant communication and endless resource utilisation. Studies suggest that mobile phones have been implicated as reservoirs of bacterial pathogens, with the potential to cause nosocomial infection. This study aimed to investigate the presence of Respiratory Syncytial Virus, Adenovirus and Influenza Virus on HCWs mobile phones and to identify risk factors implied by HCWs practice of mobile phones in a clinical paediatric environment. Fifty HCWs' mobile phones were swabbed over both sides of the mobile phone, for testing of viral contamination during 8 days in January 2015. During the same period, a questionnaire investigating usage of mobile phones was given to 101 HCWs. Ten per cent of sampled phones were contaminated with viral pathogens tested for. A total of 91% of sampled individuals by questionnaire used their mobile phone within the workplace, where 37% used their phone at least every hour. Eighty-nine (88%) responders were aware that mobile phones could be a source of contamination, yet only 13 (13%) disinfect their cell phone regularly. Mobile phones in clinical practice may be contaminated with viral pathogenic viruses. HCWs use their mobile phone regularly while working and, although the majority are aware of contamination, they do not disinfect their phones.

Polychlorinated biphenyl contamination of nursing mothers' milk in Michigan

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

Wickizer, T.M.; Brilliant, L.B.; Copeland, R.

As part of an effort to assess the extent and distribution of PCB contamination in the human population of Michigan, PCB levels in the breast milk of Michigan nursing mothers were investigated. All of the 1057 samples collected from 68 counties contained PCB residues ranging from trace amounts to 5.1 ppm. The mean PCB level was 1.496 ppm. The public health significance of PCB contamination in human populations and the implications of PCB contamination of human milk for current breast-feeding practices are discussed. Several precautionary measures for nursing mothers are recommended.

Contamination control engineering design guidelines for the aerospace community

NASA Technical Reports Server (NTRS)

Tribble, A. C. (Principal Investigator); Boyadjian, B.; Davis, J.; Haffner, J.; McCullough, E.

1996-01-01

Thermal control surfaces, solar arrays, and optical devices may be adversely affected by a small quantity of molecular and/or particulate contamination. What is rarely discussed is how one: (1) quantifies the level of contamination that must be maintained in order for the system to function properly, and (2) enforces contamination control to ensure compliance with requirements. This document is designed to address these specific issues and is intended to serve as a handbook on contamination control for the reader, illustrating process and methodology while providing direction to more detailed references when needed. The effects of molecular contamination on reflecting and transmitting surfaces are examined and quantified in accordance with MIL STD 1246C. The generation, transportation, and deposition of molecular contamination is reviewed and specific examples are worked to illustrate the process a design engineer can use to estimate end of life cleanliness levels required by solar arrays, thermal control surfaces, and optical surfaces. A similar process is used to describe the effect of particulate contamination as related to percent area coverage (PAC) and bi-directional reflectance distribution function (BRDF). Relationships between PAC and surface cleanliness, which include the effects of submicron sized particles, are developed and BRDF is related to specific sensor design parameters such as Point Source Transmittance (PST). The pros and cons of various methods of preventing, monitoring, and cleaning surfaces are examined and discussed.

Post-harvest practices linked with ochratoxin A contamination of coffee in three provinces of Cordillera Administrative Region, Philippines.

PubMed

Barcelo, Jonathan M; Barcelo, Racquel C

2018-02-01

One of the emerging concerns in the Cordillera Administrative Region, Philippines is ochratoxin A (OTA) contamination in coffee. During 2015 to 2016, a total of 51 Arabica (Coffea arabica) coffee samples from Benguet province and 71 Robusta (Coffea canephora var. Robusta) coffee samples from the provinces of Ifugao and Kalinga were analysed for OTA contamination. The OTA-producing fungal contaminants during drying and storage of Arabica and Robusta coffee were Aspergillus niger and Aspergillus ochraceus. Ochratoxin A was more commonly detected in Robusta coffee (36.6%) than in Arabica coffee (21.6%). Among the contaminated samples, Robusta coffee cherries in the drying yard had the highest mean OTA level (120.2 μg kg -1 , n = 10) while roasted Robusta coffee beans had the lowest mean level (4.8 μg kg -1 , n = 9). The onset of contamination of Arabica coffee occurred during storage, with a mean OTA level of 46.7 μg kg -1 (n = 9). Roasted coffee had lower OTA content although five samples had levels >5.0 μg kg -1 . Pearson Chi-square analysis (χ 2 ) and Fisher's exact test revealed that several post-harvest practices involving non-removal of the husk or hull and mixing of defective coffee were significantly associated with the occurrence of OTA during drying and storage (p < 0.05). No significant associations, however, were identified during roasting. This study suggests that the post-harvest practices in Cordillera Administrative Region should focus on the removal of defective coffee in all stages of post-harvest and rapid reduction of moisture content particularly during drying.

The rationale for simple approaches for sustainability assessment and management in contaminated land practice.

PubMed

Bardos, R Paul; Bone, Brian D; Boyle, Richard; Evans, Frank; Harries, Nicola D; Howard, Trevor; Smith, Jonathan W N

2016-09-01

The scale of land-contamination problems, and of the responses to them, makes achieving sustainability in contaminated land remediation an important objective. The Sustainable Remediation Forum in the UK (SuRF-UK) was established in 2007 to support more sustainable remediation practice in the UK. The current international interest in 'sustainable remediation' has achieved a fairly rapid consensus on concepts, descriptions and definitions for sustainable remediation, which are now being incorporated into an ISO standard. However the sustainability assessment methods being used remain diverse with a range of (mainly) semi-quantitative and quantitative approaches and tools developed, or in development. Sustainability assessment is site specific and subjective. It depends on the inclusion of a wide range of considerations across different stakeholder perspectives. Taking a tiered approach to sustainability assessment offers important advantages, starting from a qualitative assessment and moving through to semi-quantitative and quantitative assessments on an 'as required' basis only. It is also clear that there are a number of 'easy wins' that could improve performance against sustainability criteria right across the site management process. SuRF-UK has provided a checklist of 'sustainable management practices' that describes some of these. This paper provides the rationale for, and an outline of, and recently published SuRF-UK guidance on preparing for and framing sustainability assessments; carrying out qualitative sustainability assessment; and simple good management practices to improve sustainability across contaminated land management activities. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Atmosphere Resource Recovery and Environmental Monitoring Trace Contaminant Control Through FY 2012

NASA Technical Reports Server (NTRS)

Perry, J. L.; Pruitt, M. W.; Wheeler, R. M.; Monje, O.

2013-01-01

Trace contaminant control has been a concern of spacecraft designers and operators from early in the progression of manned spaceflight. Significant technological advancement has occurred since the first designs were implemented in the 1960s, culminating in the trace contaminant control system currently in use aboard the International Space Station as part of the atmosphere revitalization system.

Potential sources of Campylobacter infection on chicken farms: contamination and control of broiler-harvesting equipment, vehicles and personnel.

PubMed

Ridley, A; Morris, V; Gittins, J; Cawthraw, S; Harris, J; Edge, S; Allen, V

2011-07-01

To test the efficacy of enhanced biosecurity measures on poultry farms for reducing environmental contamination with Campylobacter during partial depopulation of broiler flocks prior to normal slaughter age. The study has also evaluated the risk of infection from live-bird transport crates that are routinely cleaned at the slaughterhouse, but may remain contaminated. On-farm sampling and Campylobacter isolation was undertaken to compare the prevalence of contamination on vehicles, equipment and catching personnel during farm visits that took place under normal or enhanced biosecurity. Campylobacters were found in almost all types of sample examined and enhanced biosecurity reduced the prevalence. However, the additional measures failed to prevent colonisation of the flocks. For transport crates, challenge trials involved exposure of broilers to commercially cleaned crates and genotyping of any campylobacters isolated. The birds were rapidly colonised with the same genotypes as those isolated from the cleaned crates. The enhanced biosecurity measures were insufficient to prevent flock colonisation, and the problem was exacerbated by inadequate cleaning of transport crates at the slaughterhouse. Current commercial practices in the United Kingdom facilitate the spread of campylobacters among broiler chicken flocks. Prevention of flock infection appears to require more stringent biosecurity than that studied here. © 2011 Crown Copyright. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Contamination control program for the Extreme Ultraviolet Explorer instruments

NASA Technical Reports Server (NTRS)

Ray, David C.; Malina, Roger F.; Welsh, Barry Y.; Austin, James D.; Teti, Bonnie Gray

1989-01-01

A contamination-control program has been instituted for the optical components of the EUV Explorer satellite, whose 80-900 A range performance is easily degraded by particulate and molecular contamination. Cleanliness requirements have been formulated for the design, fabrication, and test phases of these instruments; in addition, contamination-control steps have been taken which prominently include the isolation of sensitive components in a sealed optics cavity. Prelaunch monitoring systems encompass the use of quartz crystal microbalances, particle witness plates, direct flight hardware sampling, and optical witness sampling of EUV scattering and reflectivity.

Managing dredged material in the coastal zone of the Baltic Sea.

PubMed

Staniszewska, Marta; Boniecka, Helena

2017-01-01

This article deals with the legal and practical recommendations for the management of dredged material in the riparian countries of the Baltic Sea. The recommendations are contained in three conventions: LC, 2000. London Convention (1972), Convention on the Protection of the Marine Environment of the Baltic Sea area (Helsinki Convention) (1992), the OSPAR Convention (1972). Different approaches to evaluating the contamination level of dredge spoils, used by the Baltic Sea riparian countries, have been characterized. The differences in those approaches manifest themselves by various concentration limits for contaminants, which form a basis for the classification of dredged material as either contaminated or non-contaminated, and thus determine how the spoils will be processed further. Based on the collected information about the concentration limits for contaminants of surface sediments in the coastal ports, it was pointed out that it is necessary to conduct routine monitoring of heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, tributyltin, and petroleum hydrocarbons in dredged sediments in all the Baltic Sea states. On the other hand, the monitoring of polychlorinated dibenzo-p-dioxins/furans, organochlorine, and organophosphoric pesticides is only needed in locations that are suspected of historical or being the local contamination sources. Due to significant economic limitations of chemical determinations, it is important to consider a simple screening test of sediment that would say whether sediment may be "contaminated" and qualifies for more detailed and costly chemical research. It may be typical basic physical-chemical analysis of sediments or ecotoxicological classification of sediments.Despite environmentally friendly tendencies, the practical application of dredged material within the Baltic Sea area is very limited. Dredged material is most frequently stored at the specifically designated sites. From among the practical uses of dredge spoils, beach nourishment is of the highest significance.In the conclusion, the new proposed management procedure of dredged material was presented.

Supercritical CO2 Cleaning System for Planetary Protection and Contamination Control Applications

NASA Technical Reports Server (NTRS)

Lin, Ying; Zhong, Fang; Aveline, David C.; Anderson, Mark S.

2012-01-01

Current spacecraft-compatible cleaning protocols involve a vapor degreaser, liquid sonication, and alcohol wiping. These methods are not very effective in removing live and dead microbes from spacecraft piece parts of slightly complicated geometry, such as tubing and loosely fitted nuts and bolts. Contamination control practices are traditionally focused on cleaning and monitoring of particulate and oily residual. Vapor degreaser and outgassing bakeout have not been proven to be effective in removing some less volatile, hydrophilic biomolecules of significant relevance to life detection. A precision cleaning technology was developed using supercritical CO2 (SCC). SCC is used as both solvent and carrier for removing organic and particulate contaminants. Supercritical fluid, like SCC, is characterized by physical and thermal properties that are between those of the pure liquid and gas phases. The fluid density is a function of the temperature and pressure. Its solvating power can be adjusted by changing the pressure or temperature, or adding a secondary solvent such as alcohol or water. Unlike a regular organic solvent, SCC has higher diffusivities, lower viscosity, and lower surface tension. It readily penetrates porous and fibrous solids and can reach hard-to-reach surfaces of the parts with complex geometry. Importantly, the CO2 solvent does not leave any residue. The results using this new cleaning device demonstrated that both supercritical CO2 with 5% water as a co-solvent can achieve cleanliness levels of 0.01 mg/cm2 or less for contaminants of a wide range of hydrophobicities. Experiments under the same conditions using compressed Martian air mix, which consists of 95% CO2, produced similar cleaning effectiveness on the hydrophobic compounds. The main components of the SCC cleaning system are a high-pressure cleaning vessel, a boil-off vessel located downstream from the cleaning vessel, a syringe-type high-pressure pump, a heat exchanger, and a back pressure regulator (BPR). After soaking the parts to be cleaned in the clean vessel for a period, the CO2 with contaminants is flushed out of the cleaning vessel using fresh CO2 in a first-in-first-out (FIFO) method. The contaminants are either precipitating out in the boil-off container or being trapped in a filter subsystem. The parts to be cleaned are secured in a basket inside and can be rotated up to 1,400 rpm by a magnetic drive. The fluid flows within the vessel generate tangential forces on the parts surfaces, enhancing the cleaning effectiveness and shortening the soaking time. During the FIFO flushing, the pump subsystem pushes fresh CO2 into the cleaning vessel at a constant flow rate between 0.01 and 200 mL/min, while the BPR regulates the pressure in the cleaning vessel to within 0.1 bar by controlling the needle position in an outlet valve. The fresh CO2 gas flows through the heat exchanger at a given temperature before entering the cleaning vessel. A platinum resistance thermometer (PRT) reads the cleaning vessel interior temperature that can be controlled to within 0.1 K. As a result, cleaning vessel temperature remains constant during the FIFO flushing. There is no change in solvent power during FIFO flushing since both temperature and pressure inside the cleaning vessel remain unchanged, thus minimizing contaminants left behind. During decompression, both temperature and pressure are strictly controlled to prevent bubbles from generating in the cleaning vessel that could stir up the contaminants that sank to the bottom by gravity.

Internalization of Listeria monocytogenes in cantaloupes during dump tank washing and hydrocooling

USDA-ARS?s Scientific Manuscript database

Recent listeriosis outbreaks and recalls associated with cantaloupes urge for studies to understand the mechanisms of cantaloupe contamination by Listeria monocytogenes. Postharvest practices such as washing and hydrocooling were suggested to facilitate the contamination of fresh fruits by human pat...

Green Remediation: Incorporating Sustainable Practices into Remediation of Contaminated Sites (Technology Primer)

EPA Science Inventory

As part of its mission to protect human health and the environment, the U. S. Environmental Protection Agency is dedicated to developing and promoting innovative cleanup strategies that restore contaminated sites to productive use, reduce associated costs, and promote environment...

21 CFR 110.35 - Sanitary operations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... against contamination of food. (1) Food-contact surfaces used for manufacturing or holding low-moisture... HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD... for contamination. Only the following toxic materials may be used or stored in a plant where food is...

Directional phytoscreening: contaminant gradients in trees for plume delineation.

PubMed

Limmer, Matt A; Shetty, Mikhil K; Markus, Samantha; Kroeker, Ryan; Parker, Beth L; Martinez, Camilo; Burken, Joel G

2013-08-20

Tree sampling methods have been used in phytoscreening applications to delineate contaminated soil and groundwater, augmenting traditional investigative methods that are time-consuming, resource-intensive, invasive, and costly. In the past decade, contaminant concentrations in tree tissues have been shown to reflect the extent and intensity of subsurface contamination. This paper investigates a new phytoscreening tool: directional tree coring, a concept originating from field data that indicated azimuthal concentrations in tree trunks reflected the concentration gradients in the groundwater around the tree. To experimentally test this hypothesis, large diameter trees were subjected to subsurface contaminant concentration gradients in a greenhouse study. These trees were then analyzed for azimuthal concentration gradients in aboveground tree tissues, revealing contaminant centroids located on the side of the tree nearest the most contaminated groundwater. Tree coring at three field sites revealed sufficiently steep contaminant gradients in trees reflected nearby groundwater contaminant gradients. In practice, trees possessing steep contaminant gradients are indicators of steep subsurface contaminant gradients, providing compass-like information about the contaminant gradient, pointing investigators toward higher concentration regions of the plume.

Transverse bacterial migration induced by chemotaxis in a packed column with structured physical heterogeneity.

PubMed

Wang, Meng; Ford, Roseanne M

2009-08-01

The significance of chemotaxis in directing bacterial migration toward contaminants in natural porous media was investigated under groundwater flow conditions. A laboratory-scale column, with a coarse-grained sand core surrounded by a fine-grained annulus, was used to simulate natural aquifers with strata of different hydraulic conductivities. A chemoattractant source was placed along the central axis of the column to model contaminants trapped in the heterogeneous subsurface. Chemotactic bacterial strains, Escherichia coli HCB1 and Pseudomonas putida F1, introduced into the column by a pulse injection, were found to alter their transport behaviors under the influence of the attractant chemical emanating from the central source. For E. coil HCB1, approximately 18% more of the total population relative to the control without attractant exited the column from the coarse sand layer due to the chemotactic effects of alpha-methylaspartate under an average fluid velocity of 5.1 m/d. Although P. putida F1 demonstrated no observable changes in migration pathways with the model contaminant acetate under the same flow rate, when the flow rate was reduced to 1.9 m/d, approximately 6-10% of the population relative to the control migrated from the fine sand layer toward attractant into the coarse sand layer. Microbial transport properties were further quantified by a mathematical model to examine the significance of bacterial motility and chemotaxis under different hydrodynamic conditions, which suggested important considerations for strain selection and practical operation of bioremediation schemes.

Dynamics of indigenous bacterial communities associated with crude oil degradation in soil microcosms during nutrient-enhanced bioremediation.

PubMed

Chikere, Chioma B; Surridge, Karen; Okpokwasili, Gideon C; Cloete, Thomas E

2012-03-01

Bacterial population dynamics were examined during bioremediation of an African soil contaminated with Arabian light crude oil and nutrient enrichment (biostimulation). Polymerase chain reaction followed by denaturing gradient gel electrophoresis (DGGE) were used to generate bacterial community fingerprints of the different treatments employing the 16S ribosomal ribonucleic acid (rRNA) gene as molecular marker. The DGGE patterns of the nutrient-amended soils indicated the presence of distinguishable bands corresponding to the oil-contaminated-nutrient-enriched soils, which were not present in the oil-contaminated and pristine control soils. Further characterization of the dominant DGGE bands after excision, reamplification and sequencing revealed that Corynebacterium spp., Dietzia spp., Rhodococcus erythropolis sp., Nocardioides sp., Low G+C (guanine plus cytosine) Gram positive bacterial clones and several uncultured bacterial clones were the dominant bacterial groups after biostimulation. Prominent Corynebacterium sp. IC10 sequence was detected across all nutrient-amended soils but not in oil-contaminated control soil. Total heterotrophic and hydrocarbon utilizing bacterial counts increased significantly in the nutrient-amended soils 2 weeks post contamination whereas oil-contaminated and pristine control soils remained fairly stable throughout the experimental period. Gas chromatographic analysis of residual hydrocarbons in biostimulated soils showed marked attenuation of contaminants starting from the second to the sixth week after contamination whereas no significant reduction in hydrocarbon peaks were seen in the oil-contaminated control soil throughout the 6-week experimental period. Results obtained indicated that nutrient amendment of oil-contaminated soil selected and enriched the bacterial communities mainly of the Actinobacteria phylogenetic group capable of surviving in toxic contamination with concomitant biodegradation of the hydrocarbons. The present study therefore demonstrated that the soil investigated harbours hydrocarbon-degrading bacterial populations which can be biostimulated to achieve effective bioremediation of oil-contaminated soil.

21 CFR 211.113 - Control of microbiological contamination.

Code of Federal Regulations, 2011 CFR

2011-04-01

... shall include validation of all aseptic and sterilization processes. [43 FR 45077, Sept. 29, 1978, as... Process Controls § 211.113 Control of microbiological contamination. (a) Appropriate written procedures...

21 CFR 211.113 - Control of microbiological contamination.

Code of Federal Regulations, 2012 CFR

2012-04-01

... shall include validation of all aseptic and sterilization processes. [43 FR 45077, Sept. 29, 1978, as... Process Controls § 211.113 Control of microbiological contamination. (a) Appropriate written procedures...

21 CFR 211.113 - Control of microbiological contamination.

Code of Federal Regulations, 2014 CFR

2014-04-01

... shall include validation of all aseptic and sterilization processes. [43 FR 45077, Sept. 29, 1978, as... Process Controls § 211.113 Control of microbiological contamination. (a) Appropriate written procedures...

21 CFR 211.113 - Control of microbiological contamination.

Code of Federal Regulations, 2013 CFR

2013-04-01

... shall include validation of all aseptic and sterilization processes. [43 FR 45077, Sept. 29, 1978, as... Process Controls § 211.113 Control of microbiological contamination. (a) Appropriate written procedures...

Microbiological quality and safe handling of enteral diets in a hospital in Minas Gerais, Brazil

PubMed Central

Pinto, Raquel Oliveira Medrado; Correia, Eliznara Fernades; Pereira, Keyla Carvalho; Costa, Paulo de Souza; da Silva, Daniele Ferreira

2015-01-01

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. PMID:26273278

'Unfit for human consumption': a study of the contamination of formula milk fed to young children in East Java, Indonesia.

PubMed

Gibson, Sarah; Sahanggamu, Daniel; Fatmaningrum, Dewi; Curtis, Val; White, Sian

2017-10-01

To examine levels of bacterial contamination in formula feeding bottles in Sidoarjo, East Java, and to assess the preparation practices that may have been responsible. A cross-sectional study was conducted among 92 randomly selected households with children under the age of two who were bottle-fed formula. In each household, we carried out video observation of mothers/caregivers preparing bottles, and examined samples of formula for coliform bacteria and Escherichia coli (E. coli). In-depth interviews were conducted with a subsample of 20 mothers. A total of 88% of the formula feeds were contaminated with total coliforms at a level >10 MPN/ml, and 45% contained E. coli. These feeds were defined as 'unfit for human consumption'. In the video observations, none of the mothers complied with all five WHO-recommended measures of hygienic formula feed preparation. Only two mothers washed their hands with soap prior to formula preparation. Most mothers also failed to clean or sterilise the bottle and clean the preparation area. In-depth interviews confirmed that such suboptimal hygiene practices were common. The high levels of contamination found highlight that bottles are an important faecal-oral exposure pathway resulting from poor hygiene practices during bottle preparation. © 2017 John Wiley & Sons Ltd.

Installation-Restoration Program environmental-technology development. Task order 3. Use of activated carbon for treatment of explosives-contaminated ground water at the Badger Army Ammunition Plant (BAAP). Final report Jun 88-Aug 89

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

Wujcik, W.J.; Lowe, W.L.; Marks, P.J.

1989-08-01

The United States Army operates explosives manufacturing plants to produce various forms of explosives used in military ordnance. Manufacturing activities at such plants result in the production of organic wastewaters that contain both explosive residues and other organic chemicals. Several treatment technologies have been developed to treat these wastewaters for final discharge. Past waste handling practices at explosives manufacturing plants commonly included the use of the unlined lagoons or pits for containing process wastewaters. As a result of these past practices, some explosives residues may leach through the soil and contaminated groundwater. Therefore, the treatment of contaminated groundwater may bemore » required.« less

Flow-through bioassay for measuring bioaccumulation of toxic substances from sediment

USGS Publications Warehouse

Mac, Michael J.; Edsall, Carol C.; Hesselberg, Robert J.; Sayers, Richard E.

1984-01-01

Over 10 million cubic meters of sediment are dredged annually from Great Lakes waterways. Because much of this material is taken from harbors, connecting channels, and other nearshore areas that often are contaminated with toxic substances, the sediments proposed for dredging need to be evaluated for the presence of bioavailable contaminants and the potential for toxicity to the biota. Sound decisions on the appropriate disposal of the dredged material can be made only after such an evaluation. Presently, no standardized procedure exists for evaluating dredged material in freshwater systems although current criteria for discharge of dredged material into marine water have been developed (USEPA/CE 1977). In the ocean discharge guideline, it is recommended that bioassays be conducted on liquid, solid, and suspended particulate phases of dredged material. because it appears that the solid phase has the greatest potential for environmental damage and because measurement of bioaccumulation must be made to evaluate sediments for disposal (USEPA/CE 1977, Seeyle and Mac 1983), we developed a bioassay for testing the solid phase of dredged material that measures the survival of organisms and, perhaps more important, the bioaccumulation of toxic substances by aquatic organisms from naturally contaminated sediments (Peddicord et al. 1980; Rubinstein et al. 1980, 1983; Seeyle st al. 1982), several have used testing methods that result in unacceptable mortality to control organisms (Bahnick et al. 1981, Prater et al. 1983). Our bioassay is intended to estimate the potential for bioaccumlation of contaminants from sediments that are not acutely toxic to test organisms, but are suspected of containing persistent contaminants. By using test organisms that are not highly susceptible to toxic compounds, the bioaccumulation test allows estimation of the potential food-chain accumulation of contaminants that may occur in local biota from surficial sediments. In practice, bioaccumulation observed in this bioassay by organisms exposed to test sediments (sediments to be dredged) would be compared to bioaccumulation observed from sediments collected from a reference site (e.g. a disposal site or open lake), and also from control sediments (relatively clean sediment). Decisions could then be based on a comparison of results between tests and reference sediments to determine if disposal would cause dehydration to the habitat, and between reference and control sediment to determine if even the reference material is seriously contaminated. Although the test is not intended to be a toxicity test per se, use of test, reference, and control sediments enables interpretation of any mortality of organisms that may occur during the bioassays. High mortality in bioassays with test or reference sediment would indicate acute toxicity of sediments in the project area. However if high mortality occurs in all three sediments, it can be assumed that the organisms were not in a healthy state at the time of testing. We describe the results of 10-day sediment bioassays in which both mortality and bioaccumulation were measured in four aquatic organisms. We exposed two infaunal organisms and two species of fish to test and control sediments in the laboratory.

Bacterial Contamination of Hospital Bed-Control Handsets in a Surgical Setting: A Potential Marker of Contamination of the Healthcare Environment

PubMed Central

Brady, RRW; Kalima, P; Damani, NN; Wilson, RG; Dunlop, MG

2007-01-01

INTRODUCTION Patients undergoing colorectal surgical resections have a high incidence of surgical site infection (SSI). Many patient-specific risk factors have been recognised in association with SSI in such patients, but environmental contamination is increasingly recognised as a contributor to hospital-acquired infection (HAI). This study set out to describe the bacterial contamination of the patient environment, using hospital bed-control handsets, as they are frequently handled by both staff and patients and represent a marker of environmental contamination. PATIENTS AND METHODS On two unannounced sampling events, 1 week apart, 140 bacteriological assessments were made of 70 hospital bed control handsets within a specialist colorectal surgical unit. RESULTS Of the handsets examined, 67 (95.7%) demonstrated at least one bacterial species (52.9% grew 1, 30% grew 2 and 12.9% grew 3 or more bacterial species). Of these, 29 (41.4%) bed-control handsets grew bacteria known to cause nosocomial infection, including 22 (31.4%) handsets which grew Enterococcus spp., 9 (12.9%) which grew MRSA, 2 (2.9%) which grew MSSA, 2 (2.9%) which grew coliforms, and 1 (1.4%) handset which grew anaerobes. At 1-week follow-up, 31 bed-control handsets showed evidence of contamination by the same bacterial species. CONCLUSIONS This study revealed high levels of bacteria known to cause HAI, contaminating hospital bed-control handsets in a surgical setting. Further study is now required to confirm whether hospital environmental contamination is causally involved in SSI. PMID:17959000

Salmonella and produce: survival in the plant environment and implications in food safety.

PubMed

Fatica, Marianne K; Schneider, Keith R

2011-01-01

There has been a continuous rise in the number of produce-based foodborne outbreaks in the recent decades despite the perception that foodborne diseases were primarily linked to animal-based products. The Centers for Disease Control and Prevention (CDC) estimates that 95% of Salmonella-based infections originate from foodborne sources, with multiple produce-based salmonellosis outbreaks occurring since 1990. The contamination of produce in both the pre-harvest and post-harvest produce environments is challenging to eliminate since produce is consumed as a raw, fresh commodity. Salmonella spp. contamination is possible through contact with the produce in the field as well as in the processing facility. The field contamination of produce infers the ability of Salmonella spp. to survive on the plant surface. The fitness of Salmonella spp. in the plant habitat is limited as opposed to naturally plant-associated bacteria, but survival is possible. The use of intensive farming practices, globalization of food products, high demand for convenience food products, and increased foodborne disease surveillance also have unknown ramifications in the ascending trends of produce-based outbreaks. A better understanding of the ecology of Salmonella spp. in the plant environment as well as the processing, food handling, and surveillance factors affecting the incidence of foodborne outbreaks will provide a comprehensive view of the etiology and epidemiology of produce-associated foodborne outbreaks. An understanding of the outbreaks and the factors facilitating produce contamination will allow for the development of intervention procedures and strategies to reduce the risk of produce contamination by Salmonella spp.

Phytosiderophore effects on subsurface actinide contaminants: potential for phytostabilization and phytoextraction.

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

Ruggiero, C. E.; Twary, S. N.; Deladurantaye, E.

2003-01-01

In recognition of the need for a safe, effective technology for long term Pu/Th/Actinide stabilization or removal from soils, we have begun an investigation of the potential for phytoremediation (phytostabilization and/or phytoextraction) of Pu and other actinide soil contaminants at DOE sites using phytosiderophore producing plants, and are investigating the contribution of phytosiderophores to actinide mobility in the subsurface environment. Phytoremediation and Phytostabilization have been proven to be a cost-effective, safe, efficient, and publicly acceptable technology for clean up and/or stabilization of contaminant metals . However, no phyto-based technologies have been developed for stabilization or removal of plutonium from soilsmore » and groundwater, and very few have been investigated for other actinides . Current metal-phytostabilization and phytoremediation techniques, predominately based around lead, nickel, and other soft-metal phytoextraction, will almost certainly be inadequate for plutonium due its distinct chemical properties . Phytosiderophore-based phytoremediation may provide technically and financially practical methods for remediation and long-term stewardship of soils that have low to moderate, near surface actinide contamination . We plan to demonstrate potential benefits of phytosiderophore-producing plants for long-term actinide contaminant stabilization by the plant's prevention of soil erosion and actinide migration through hydraulic control and/or through actinide removal through phytoextraction . We may also show possible harm caused by these plants through increased presence of actinide chelators that could increase actinide mobilization and migration in the subsurface environment. This information can then be directly applied by either removal of harmful plants, or be used to develop plant-based soil stabilization/remediation technologies .« less

Pre- and postharvest preventive measures and intervention strategies to control microbial food safety hazards of fresh leafy vegetables.

PubMed

Gil, Maria I; Selma, Maria V; Suslow, Trevor; Jacxsens, Liesbeth; Uyttendaele, Mieke; Allende, Ana

2015-01-01

This review includes an overview of the most important preventive measures along the farm to fork chain to prevent microbial contamination of leafy greens. It also includes the technological and managerial interventions related to primary production, postharvest handling, processing practices, distribution, and consumer handling to eliminate pathogens in leafy greens. When the microbiological risk is already present, preventive measures to limit actual contamination events or pathogen survival are considered intervention strategies. In codes of practice the focus is mainly put on explaining preventive measures. However, it is also important to establish more focused intervention strategies. This review is centered mainly on leafy vegetables as the commodity identified as the highest priority in terms of fresh produce microbial safety from a global perspective. There is no unique preventive measure or intervention strategy that could be applied at one point of the food chain. We should encourage growers of leafy greens to establish procedures based on the HACCP principles at the level of primary production. The traceability of leafy vegetables along the chain is an essential element in ensuring food safety. Thus, in dealing with the food safety issues associated with fresh produce it is clear that a multidisciplinary farm to fork strategy is required.

A flexible framework for process-based hydraulic and water ...

EPA Pesticide Factsheets

Background Models that allow for design considerations of green infrastructure (GI) practices to control stormwater runoff and associated contaminants have received considerable attention in recent years. While popular, generally, the GI models are relatively simplistic. However, GI model predictions are being relied upon by many municipalities and State/Local agencies to make decisions about grey vs. green infrastructure improvement planning. Adding complexity to GI modeling frameworks may preclude their use in simpler urban planning situations. Therefore, the goal here was to develop a sophisticated, yet flexible tool that could be used by design engineers and researchers to capture and explore the effect of design factors and properties of the media used in the performance of GI systems at a relatively small scale. We deemed it essential to have a flexible GI modeling tool that is capable of simulating GI system components and specific biophysical processes affecting contaminants such as reactions, and particle-associated transport accurately while maintaining a high degree of flexibly to account for the myriad of GI alternatives. The mathematical framework for a stand-alone GI performance assessment tool has been developed and will be demonstrated.Framework Features The process-based model framework developed here can be used to model a diverse range of GI practices such as green roof, retention pond, bioretention, infiltration trench, permeable pavement and

Trace chemical contaminant generation rates for spacecraft contamination control system design

NASA Technical Reports Server (NTRS)

Perry, J. L.

1995-01-01

A spacecraft presents a unique design challenge with respect to providing a comfortable environment in which people can live and work. All aspects of the spacecraft environmental design including the size of the habitable volume, its temperature, relative humidity, and composition must be considered to ensure the comfort and health of the occupants. The crew members and the materials selected for outfitting the spacecraft play an integral part in designing a habitable spacecraft because material offgassing and human metabolism are the primary sources for continuous trace chemical contaminant generation onboard a spacecraft. Since these contamination sources cannot be completely eliminated, active control processes must be designed and deployed onboard the spacecraft to ensure an acceptably clean cabin atmosphere. Knowledge of the expected rates at which contaminants are generated is very important to the design of these processes. Data from past spacecraft missions and human contaminant production studies have been analyzed to provide this knowledge. The resulting compilation of contaminants and generation rates serve as a firm basis for past, present, and future contamination control system designs for space and aeronautics applications.

An Outbreak of Human Listeriosis in England between 2010 and 2012 Associated with the Consumption of Pork Pies.

PubMed

Awofisayo-Okuyelu, A; Arunachalam, N; Dallman, T; Grant, K A; Aird, H; McLauchlin, J; Painset, A; Amar, C

2016-05-01

An outbreak of listeriosis in England affecting 14 people between 2010 and 2012 and linked to the consumption of pork pies was investigated. All 14 individuals were older than 55 years, 12 were men, and 10 reported the presence of an underlying condition. All were resident in or had visited either of two English regions and were infected with the same strain of Listeria monocytogenes. In interviews with 12 patients, 9 reported eating pork pies, and individuals that consumed pork pies were significantly more likely to be infected with an outbreak strain than were individuals with sporadic cases of listeriosis infections in England from 2010 to 2012. Pork pies were purchased from seven retailers in South Yorkshire or the East Midlands, and the outbreak strain was recovered from pork pies supplied by only the producer in South Yorkshire. The outbreak strain was also recovered from samples of finished product and from environmental samples collected from the manufacturer. The likely source of contamination was environmental sites within the manufacturing environment, and the contamination was associated with the process of adding gelatin to the pies after cooking. Inadequate temperature control and poor hygienic practices at one of the retailers were also identified as possible contributory factors allowing growth of the pathogen. Following improvements in manufacturing practices and implementation of additional control measures at the retailers' premises, L. monocytogenes was not recovered from subsequent food and environmental samples, and the outbreak strain was not detected in further individuals with listeriosis in England.

21 CFR 111.15 - What sanitation requirements apply to your physical plant and grounds?

Code of Federal Regulations, 2014 CFR

2014-04-01

... PRACTICE IN MANUFACTURING, PACKAGING, LABELING, OR HOLDING OPERATIONS FOR DIETARY SUPPLEMENTS Physical... contamination of components, dietary supplements, or contact surfaces. The methods for adequate ground... constitute a source of contamination in areas where components, dietary supplements, or contact surfaces are...

21 CFR 111.15 - What sanitation requirements apply to your physical plant and grounds?

Code of Federal Regulations, 2012 CFR

2012-04-01

... PRACTICE IN MANUFACTURING, PACKAGING, LABELING, OR HOLDING OPERATIONS FOR DIETARY SUPPLEMENTS Physical... contamination of components, dietary supplements, or contact surfaces. The methods for adequate ground... constitute a source of contamination in areas where components, dietary supplements, or contact surfaces are...

DEVELOPING TOOLS FOR MONITORED NATURAL RECOVERY OF PCB-CONTAMINATED SEDIMENTS AT LAKE HARTWELL, SC

EPA Science Inventory

Contaminated sediments pose a risk to human health and the environment . The management of this risk is currently limited practically to three technologies: dredging, capping, and natural recovery. Monitored natural recovery relies on the natural burial and removal mechanisms to...

CONTAMINANT FLUX RESPONSES TO THERMAL TREATMENT OF DNAPL SOURCE ZONES (ABSTRACT ONLY)

EPA Science Inventory

Contaminant flux is being proposed as a metric to help elucidate the benefits of DNAPL source-zone remedial efforts. While it is clear that aggressive remediation technologies can rapidly remove DNAPL mass, experience has shown that complete removal is often not practicable. H...

Contamination control in hybrid microelectronic modules. Part 3: Specifications for coating material and process controls

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Resin systems for coating hybrids prior to hermetic sealing are described. The resin systems are a flexible silicone junction resin system and a flexible cycloaliphatic epoxy resin system. The coatings are intended for application to the hybrid after all the chips have been assembled and wire bonded, but prior to hermetic sealing of the package. The purpose of the coating is to control particulate contamination by immobilizing particles and by passivating the hybrid. Recommended process controls for the purpose of minimizing contamination in hybrid microcircuit packages are given. Emphasis is placed on those critical hybrid processing steps in which contamination is most likely to occur.

Control group design, contamination and drop-out in exercise oncology trials: a systematic review.

PubMed

Steins Bisschop, Charlotte N; Courneya, Kerry S; Velthuis, Miranda J; Monninkhof, Evelyn M; Jones, Lee W; Friedenreich, Christine; van der Wall, Elsken; Peeters, Petra H M; May, Anne M

2015-01-01

Important considerations for exercise trials in cancer patients are contamination and differential drop-out among the control group members that might jeopardize the internal validity. This systematic review provides an overview of different control groups design characteristics of exercise-oncology trials and explores the association with contamination and drop-out rates. Randomized controlled exercise-oncology trials from two Cochrane reviews were included. Additionally, a computer-aided search using Medline (Pubmed), Embase and CINAHL was conducted after completion date of the Cochrane reviews. Eligible studies were classified according to three control group design characteristics: the exercise instruction given to controls before start of the study (exercise allowed or not); and the intervention the control group was offered during (any (e.g., education sessions or telephone contacts) or none) or after (any (e.g., cross-over or exercise instruction) or none) the intervention period. Contamination (yes or no) and excess drop-out rates (i.e., drop-out rate of the control group minus the drop-out rate exercise group) were described according to the three design characteristics of the control group and according to the combinations of these three characteristics; so we additionally made subgroups based on combinations of type and timing of instructions received. 40 exercise-oncology trials were included based on pre-specified eligibility criteria. The lowest contamination (7.1% of studies) and low drop-out rates (excess drop-out rate -4.7±9.2) were found in control groups offered an intervention after the intervention period. When control groups were offered an intervention both during and after the intervention period, contamination (0%) and excess drop-out rates (-10.0±12.8%) were even lower. Control groups receiving an intervention during and after the study intervention period have lower contamination and drop-out rates. The present findings can be considered when designing future exercise-oncology trials.

Contaminants in milk and impact of heating: an assessment study.

PubMed

Awasthi, Vandana; Bahman, Sanjivan; Thakur, Lalit K; Singh, Santosh Kumar; Dua, Ajit; Ganguly, Sanjeev

2012-01-01

The major contaminants usually encountered in milk and milk products include pesticide residues, heavy metals, and aflatoxin M1 (AFM1). Primarily, milk get contaminated before milching, from the cattle feed, from sources/materials used during the processing of milk as well as improper handling of the milk during the pre- and postprocessing period. The purpose of this study was to evaluate the effect of household practices on milk contaminants. Samples of pasteurized as well as unpasteurized milk (Vendor's milk) were analyzed for AFM1, pesticide residues, and heavy metals. Simulating the household practices, the impact of boiling on these contaminants was assessed. The contaminant Aflatoxin M1 (AFM1) was detected at a concentration ranging from 0.071-0.075 ppb in unpasteurized as well as pasteurized milk samples analyzed during the course of study. Moreover, boiling had no impact on the quantity of AFM1 present in the milk. Pesticides and heavy metal contents were found to be within acceptable limits in all the milk samples tested. Mycotoxins especially aflatoxins in cattle feed and their consequential presence in milk and milk products is a serious concern world over as they are reported carcinogens. These fungal toxins are resistant to high temperatures and may lead to various health hazards. Preventive steps must be taken at each stage to ensure good quality of milk and milk products free from these contaminants. Awareness programs and education for the dairy farmers and milk processors may be helpful in this regard.

Bioremediation of petroleum hydrocarbon-contaminated ground water: The perspectives of history and hydrology

USGS Publications Warehouse

Chapelle, F.H.

1999-01-01

Bioremediation, the use of microbial degradation processes to detoxify environmental contamination, was first applied to petroleum hydrocarbon-contaminated ground water systems in the early 1970s. Since that time, these technologies have evolved in some ways that were clearly anticipated early investigators, and in other ways that were not foreseen. The expectation that adding oxidants and nutrients to contaminated aquifers would enhance biodegradation, for example, has been born out subsequent experience. Many of the technologies now in common use such as air sparging, hydrogen peroxide addition, nitrate addition, and bioslurping, are conceptually similar to the first bioremediation systems put into operation. More unexpected, however, were the considerable technical problems associated with delivering oxidants and nutrients to heterogeneous ground water systems. Experience has shown that the success of engineered bioremediation systems depends largely on how effectively directions and rates of ground water flow can be controlled, and thus how efficiently oxidants and nutrients can be delivered to contaminated aquifer sediments. The early expectation that injecting laboratory-selected or genetically engineered cultures of hydrocarbon-degrading bacteria into aquifers would be a useful bioremediation technology has not been born out subsequent experience. Rather, it appears that petroleum hydrocarbon-degrading bacteria are ubiquitous in ground water systems and that bacterial addition is usually unnecessary. Perhaps the technology that was least anticipated early investigators was the development of intrinsic bioremediation. Experience has shown that natural attenuation mechanisms - biodegradation, dilution, and sorption - limit the migration of contaminants to some degree in all ground water systems. Intrinsic bioremediation is the deliberate use of natural attenuation processes to treat contaminated ground water to specified concentration levels at predetermined points in the aquifer. In current practice, intrinsic bioremediation of petroleum hydrocarbons requires a systematic assessment to show that ambient natural attenuation mechanisms are efficient enough to meet regulatory requirements and a monitoring program to verify that performance requirements are met in the future.

Evaluating the potential use of Tamarix gallica L. for phytoremediation practices in heavy-metal polluted soils

NASA Astrophysics Data System (ADS)

Abou Jaoudé, R.; Pricop, A.; Laffont-Schwob, I.; Prudent, P.; Rabier, J.; Masotti, V.; de Dato, G.; De Angelis, P.

2012-04-01

The rapid growth of population, the increased urbanisation and the expansion of industrial activities have provoked an augmented occurrence of soil contamination by heavy-metals. Important sources of contamination are industrial, mining and military infrastructures, which are often abandoned without performing the appropriate reclamation work. In the Mediterranean Basin, where coastal areas are largely affected by human overexploitation, the use of species able to tolerate heavy-metals and other abiotic stresses may represent a low-cost solution for phytoremediation in these harsh environments. Tamarix gallica L. is a widespread species in coastal Mediterranean areas, showing a high adaptability to different environments and a high tolerance of adversity. With the objective of testing local species as candidates for phytoremediation practices in heavy-metal contaminated coastal soils, cuttings of T. gallica from a wild population around Marseille (France) were planted in pots containing: 1) control soil (loamy soil and sand (2/1)), 2) half-polluted soil (loamy soil, sand and heavy-metal polluted soil (1/1/1)), and 3) polluted soil (sand and heavy-metal polluted soil (1/2)). The contaminated soils were collected in the surrounding of a former lead industry of Marseille littoral and characterised by the presence of Fe, Pb, Zn, As and Al. After three months from planting, leaf functionality was evaluated by measuring leaf gas exchanges, leaf chlorophyll fluorescence and, chlorophyll, phenols, flavonoids and anthocyanins contents. SEM observations coupled to EDXS analysis were used to determine elements (Pb, As and Al) presence and location on the leaf surface and in leaf and root tissues. T. gallica was moderately affected by the presence of heavy-metals in the soil treatments. In fact, a reduction in stomatal conductance was only observed in plants grown in the polluted soil. This reduction did not cause a significant decrease in CO2 assimilation rates. Moreover, the presence of Al on the root surface was observed in plants grown in polluted soils; this element was not detected in leaf tissues or in the leaf extruded material, suggesting a phytostabilization effect for this element. In conclusion, T. gallica could be a potential candidate for phytoremediation practices. Nevertheless, field experiments will be necessary to assess growth performances and phytoremediation potential of this species in heavy-metal polluted areas.

Socioeconomic status and exposure to disinfection by-products in drinking water in Spain.

PubMed

Castaño-Vinyals, Gemma; Cantor, Kenneth P; Villanueva, Cristina M; Tardon, Adonina; Garcia-Closas, Reina; Serra, Consol; Carrato, Alfredo; Malats, Núria; Rothman, Nathaniel; Silverman, Debra; Kogevinas, Manolis

2011-03-16

Disinfection by-products in drinking water are chemical contaminants that have been associated with cancer and other adverse effects. Exposure occurs from consumption of tap water, inhalation and dermal absorption. We determined the relationship between socioeconomic status and exposure to disinfection by-products in 1271 controls from a multicentric bladder cancer case-control study in Spain. Information on lifetime drinking water sources, swimming pool attendance, showering-bathing practices, and socioeconomic status (education, income) was collected through personal interviews. The most highly educated subjects consumed less tap water (57%) and more bottled water (33%) than illiterate subjects (69% and 17% respectively, p-value = 0.003). These differences became wider in recent time periods. The time spent bathing or showering was positively correlated with attained educational level (p < 0.001). Swimming pool attendance was more frequent among highly educated subjects compared to the illiterate (odds ratio = 3.4; 95% confidence interval 1.6-7.3). The most highly educated subjects were less exposed to chlorination by-products through ingestion but more exposed through dermal contact and inhalation in pools and showers/baths. Health risk perceptions and economic capacity may affect patterns of water consumption that can result in differences in exposure to water contaminants.

A pilot cluster randomized controlled trial of structured goal-setting following stroke.

PubMed

Taylor, William J; Brown, Melanie; William, Levack; McPherson, Kathryn M; Reed, Kirk; Dean, Sarah G; Weatherall, Mark

2012-04-01

To determine the feasibility, the cluster design effect and the variance and minimal clinical importance difference in the primary outcome in a pilot study of a structured approach to goal-setting. A cluster randomized controlled trial. Inpatient rehabilitation facilities. People who were admitted to inpatient rehabilitation following stroke who had sufficient cognition to engage in structured goal-setting and complete the primary outcome measure. Structured goal elicitation using the Canadian Occupational Performance Measure. Quality of life at 12 weeks using the Schedule for Individualised Quality of Life (SEIQOL-DW), Functional Independence Measure, Short Form 36 and Patient Perception of Rehabilitation (measuring satisfaction with rehabilitation). Assessors were blinded to the intervention. Four rehabilitation services and 41 patients were randomized. We found high values of the intraclass correlation for the outcome measures (ranging from 0.03 to 0.40) and high variance of the SEIQOL-DW (SD 19.6) in relation to the minimally importance difference of 2.1, leading to impractically large sample size requirements for a cluster randomized design. A cluster randomized design is not a practical means of avoiding contamination effects in studies of inpatient rehabilitation goal-setting. Other techniques for coping with contamination effects are necessary.

Contamination control concepts for space station customer servicing

NASA Technical Reports Server (NTRS)

Maruya, K. A.; Ryan, L. E.; Rosales, L. A.; Medler, E. H.

1986-01-01

The customer servicing operations envisioned for the space station, which include instrument repair, orbital replacement unit (ORU) changeout, and fluid replenishment for free-flying and attached payloads, are expected to create requirements for a unique contamination control subsystem for the customer servicing facility (CSF). Both the core space station and the CSF users present unique requirements/sensitivities, not all of which are currently defined with common criteria. Preliminary results from an assessment of the effects of the CSF-induced contamination environment are reported. Strategies for a comprehensive contamination control approach and a description of specific hardware devices and their applicability are discussed.

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.

Contamination control program results from three years of ground operations on the Extreme Ultraviolet Explorer instruments

NASA Technical Reports Server (NTRS)

Ray, David C.; Jelinsky, Sharon; Welsh, Barry Y.; Malina, Roger F.

1990-01-01

A stringent contamination-control plan has been developed for the optical components of the Extreme Ultraviolet Explorer instruments, whose performance in the 80-900 A wavelength range is highly sensitive to particulate and molecular contamination. The contamination-control program has been implemented over the last three years during assembly, test and calibration phases of the instrument. These phases have now been completed and the optics cavities of the instruments have been sealed until deployment in space. Various approaches are discussed which have been used during ground operations to meet optics' contamination goals within the project schedule and budget. The measured optical properties of EUV witness mirrors are also presented which remained with the flight mirrors during ground operations. These were used to track optical degradation due to contamination from the cleanroom and high-vacuum test-chamber environments.

The influence of tree species composition on the storage and mobility of semivolatile organic compounds in forest soils.

PubMed

Komprdová, Klára; Komprda, Jiří; Menšík, Ladislav; Vaňková, Lenka; Kulhavý, Jiří; Nizzetto, Luca

2016-05-15

Soil contamination with PCBs and PAHs in adjacent forest plots, characterized by a distinct composition in tree species (spruce only, mixed and beech only), was analyzed to investigate the influence of ecosystem type on contaminant mobility in soil under very similar climate and exposure conditions. Physical-chemical properties and contaminant concentrations in litter (L), organic (F, H) and mineral (A, B) soil horizons were analyzed. Contaminant distribution in the soil core varied both in relation to forest type and contaminant group/properties. Contaminant mobility in soil was assessed by examining the ratios of total organic carbon (TOC)-standardized concentrations across soil horizons (Enrichment factors, EFTOC) and the relationship between EFTOC and the octanol-water equilibrium partitioning coefficient (KOW). Contaminant distribution appeared to be highly unsteady, with pedogenic/biogeochemical drivers controlling contaminant mobility in organic layers and leaching controlling accumulation in mineral layers. Lighter PCBs displayed higher mobility in all forest types primarily controlled by leaching and, to a minor extent, diffusion. Pedogenic processes controlling the formation of soil horizons were found to be crucial drivers of PAHs and heavier PCBs distribution. All contaminants appeared to be more mobile in the soil of the broadleaved plot, followed by mixed canopy and spruce forest. Increasing proportion of deciduous broadleaf species in the forest can thus lead to faster degradation or the faster leaching of PAHs and PCBs. The composition of humic substances was found to be a better descriptor of contaminant concentration than TOC. Copyright © 2016 Elsevier B.V. All rights reserved.

Possibility of cross-contamination between dental patients by means of the saliva ejector.

PubMed

Watson, C M; Whitehouse, R L

1993-04-01

Concern about cross-contamination between dental patients prompted investigation of current suctioning practices. The possibility of the suck-back phenomenon and the presence of oral bacteria in vacuum lines were studied, and dental offices were surveyed concerning the use and disinfection of suction equipment.

SURFACE DECONTAMINATION EFFICACY STUDIES FOR ...

EPA Pesticide Factsheets

Technical Brief This Technical Brief summarizes the findings from three studies in which the decontamination efficacy was determined for various liquid contaminants when applied to various surfaces that are contaminated with blister agents (vesicants).This may provide decision-makers with practical information on surface decontaminations options during a blister agent response.

Evaluation of a Sustainable Remediation Option: Beneficial Reuse of Petroleum-Contaminated Sediment as an Energy Source

EPA Science Inventory

The characteristics of petroleum-contaminated sediment (PCS) have been evaluated to assess whether the practice of its beneficial reuse as a sole or supplemental energy source is sustainable relative to other sediment remediation options such as monitored natural recovery (MNR), ...

78 FR 22887 - Guidance for Industry on Non-Penicillin Beta-Lactam Drugs: A Current Good Manufacturing Practices...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-17

... for Preventing Cross- Contamination; Availability AGENCY: Food and Drug Administration, HHS. ACTION... require separation of manufacturing facilities to avoid cross-contamination, the only class of products... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-D-0104...

21 CFR 110.20 - Plant and grounds.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD Buildings and... operator shall be kept in a condition that will protect against the contamination of food. The methods for..., yards, and parking lots so that they do not constitute a source of contamination in areas where food is...

Comparison of enterococci and cow-specific qPAR markers in streams impacted by farms under different management practices

EPA Science Inventory

Nonpoint Sources (NPS) of pollution (e.g., agriculture, wildlife, urban runoff) are major contributors of microbial contaminants to surface waters. However, little is known about the behavior and the effect of environmental determinants on molecular markers of fecal contamination...

Modelling-based identification of factors influencing campylobacters in chicken broiler houses and on carcasses sampled after processing and chilling.

PubMed

Hutchison, M L; Taylor, M J; Tchòrzewska, M A; Ford, G; Madden, R H; Knowles, T G

2017-05-01

To identify production and processing practices that might reduce Campylobacter numbers contaminating chicken broiler carcasses. The numbers of campylobacters were determined on carcass neck skins after processing or in broiler house litter samples. Supplementary information that described farm layouts, farming conditions for individual flocks, the slaughterhouse layouts and operating conditions inside plants was collected, matched with each Campylobacter test result. Statistical models predicting the numbers of campylobacters on neck skins and in litter were constructed. Carcass microbial contamination was more strongly influenced by on-farm production practices compared with slaughterhouse activities. We observed correlations between the chilling, washing and defeathering stages of processing and the numbers of campylobacters on carcasses. There were factors on farm that also correlated with numbers of campylobacters in litter. These included bird gender, the exclusion of dogs from houses, beetle presence in the house litter and the materials used to construct the house frame. Changes in farming practices have greater potential for reducing chicken carcass microbial contamination compared with processing interventions. Routine commercial practices were identified that were correlated with lowered numbers of campylobacters. Consequently, these practices are likely to be both cost-effective and suitable for adoption into established farms and commercial processing. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

Institutional Controls: A Guide to Preparing Institutional Control Implementation and Assurance Plans at Contaminated Sites

EPA Pesticide Factsheets

The purpose of this document is to provide guidance to the EPA Regions for developing Institutional Control Implementation and Assurance Plans (ICIAPs) at contaminated sites where the response action includes an institutional controls (ICs) component.

Development of a risk-based index for source water protection planning, which supports the reduction of pathogens from agricultural activity entering water resources.

PubMed

Goss, Michael; Richards, Charlene

2008-06-01

Source water protection planning (SWPP) is an approach to prevent contamination of ground and surface water in watersheds where these resources may be abstracted for drinking or used for recreation. For SWPP the hazards within a watershed that could contribute to water contamination are identified together with the pathways that link them to the water resource. In rural areas, farms are significant potential sources of pathogens. A risk-based index can be used to support the assessment of the potential for contamination following guidelines on safety and operational efficacy of processes and practices developed as beneficial approaches to agricultural land management. Evaluation of the health risk for a target population requires knowledge of the strength of the hazard with respect to the pathogen load (massxconcentration). Manure handling and on-site wastewater treatment systems form the most important hazards, and both can comprise confined and unconfined source elements. There is also a need to understand the modification of pathogen numbers (attenuation) together with characteristics of the established pathways (surface or subsurface), which allow the movement of the contaminant species from a source to a receptor (water source). Many practices for manure management have not been fully evaluated for their impact on pathogen survival and transport in the environment. A key component is the identification of potential pathways of contaminant transport. This requires the development of a suitable digital elevation model of the watershed for surface movement and information on local groundwater aquifer systems for subsurface flows. Both require detailed soils and geological information. The pathways to surface and groundwater resources can then be identified. Details of land management, farm management practices (including animal and manure management) and agronomic practices have to be obtained, possibly from questionnaires completed by each producer within the watershed. To confirm that potential pathways are active requires some microbial source tracking. One possibility is to identify the molecular types of Escherichia coli present in each hazard on a farm. An essential part of any such index is the identification of mitigation strategies and practices that can reduce the magnitude of the hazard or block open pathways.

Insight into the prevalence and distribution of microbial contamination to evaluate water management in the fresh produce processing industry.

PubMed

Holvoet, Kevin; Jacxsens, Liesbeth; Sampers, Imca; Uyttendaele, Mieke

2012-04-01

This study provided insight into the degree of microbial contamination in the processing chain of prepacked (bagged) lettuce in two Belgian fresh-cut produce processing companies. The pathogens Salmonella and Listeria monocytogenes were not detected. Total psychrotrophic aerobic bacterial counts (TPACs) in water samples, fresh produce, and environmental samples suggested that the TPAC is not a good indicator of overall quality and best manufacturing practices during production and processing. Because of the high TPACs in the harvested lettuce crops, the process water becomes quickly contaminated, and subsequent TPACs do not change much throughout the production process of a batch. The hygiene indicator Escherichia coli was used to assess the water management practices in these two companies in relation to food safety. Practices such as insufficient cleaning and disinfection of washing baths, irregular refilling of the produce wash baths with water of good microbial quality, and the use of high product/water ratios resulted in a rapid increase in E. coli in the processing water, with potential transfer to the end product (fresh-cut lettuce). The washing step in the production of fresh-cut lettuce was identified as a potential pathway for dispersion of microorganisms and introduction of E. coli to the end product via cross-contamination. An intervention step to reduce microbial contamination is needed, particularly when no sanitizers are used as is the case in some European Union countries. Thus, from a food safety point of view proper water management (and its validation) is a critical point in the fresh-cut produce processing industry.

Use of Maize (Zea mays L.) for phytomanagement of Cd-contaminated soils: a critical review.

PubMed

Rizwan, Muhammad; Ali, Shafaqat; Qayyum, Muhammad Farooq; Ok, Yong Sik; Zia-Ur-Rehman, Muhammad; Abbas, Zaheer; Hannan, Fakhir

2017-04-01

Maize (Zea mays L.) has been widely adopted for phytomanagement of cadmium (Cd)-contaminated soils due to its high biomass production and Cd accumulation capacity. This paper reviewed the toxic effects of Cd and its management by maize plants. Maize could tolerate a certain level of Cd in soil while higher Cd stress can decrease seed germination, mineral nutrition, photosynthesis and growth/yields. Toxicity response of maize to Cd varies with cultivar/varieties, growth medium and stress duration/extent. Exogenous application of organic and inorganic amendments has been used for enhancing Cd tolerance of maize. The selection of Cd-tolerant maize cultivar, crop rotation, soil type, and exogenous application of microbes is a representative agronomic practice to enhance Cd tolerance in maize. Proper selection of cultivar and agronomic practices combined with amendments might be successful for the remediation of Cd-contaminated soils with maize. However, there might be the risk of food chain contamination by maize grains obtained from the Cd-contaminated soils. Thus, maize cultivation could be an option for the management of low- and medium-grade Cd-contaminated soils if grain yield is required. On the other hand, maize can be grown on Cd-polluted soils only if biomass is required for energy production purposes. Long-term field trials are required, including risks and benefit analysis for various management strategies aiming Cd phytomanagement with maize.

Contaminant treatment method

DOEpatents

Shapiro, Andrew Philip; Thornton, Roy Fred; Salvo, Joseph James

2003-01-01

The present invention provides a method for treating contaminated media. The method comprises introducing remediating ions consisting essentially of ferrous ions, and being peroxide-free, in the contaminated media; applying a potential difference across the contaminated media to cause the remediating ions to migrate into contact with contaminants in the contaminated media; chemically degrading contaminants in the contaminated media by contact with the remediating ions; monitoring the contaminated media for degradation products of the contaminants; and controlling the step of applying the potential difference across the contaminated media in response to the step of monitoring.

Evaluation of Commercial Off-the-Shelf Sorbents and Catalysts for Control of Ammonia and Carbon Monoxide

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Somi, George; Winchester, J. Parker; Grose, Jeffrey; Mulloth, Lila; Perry, Jay L.

2010-01-01

Designers of future space vehicles envision simplifying the Atmosphere Revitalization (AR) system by combining the functions of trace contaminant (TC) control and carbon dioxide removal into one swing-bed system. Flow rates and bed sizes of the TC and CO2 systems have historically been very different. There is uncertainty about the ability of trace contaminant sorbents to adsorb adequately in high-flow or short bed length configurations, and to desorb adequately during short vacuum exposures. There is also concern about ambient ammonia levels in the absence of a condensing heat exchanger. In addition, new materials and formulations have become commercially available, formulations never evaluated by NASA for purposes of trace contaminant control. The optimal air revitalization system for future missions may incorporate a swing-bed system for carbon dioxide (CO2) and partial trace contaminant control, with a reduced-size, low-power, targeted trace contaminant system supplying the remaining contaminant removal capability. This paper describes the results of a comparative experimental investigation into materials for trace contaminant control that might be part of such a system. Ammonia sorbents and low temperature carbon monoxide (CO) oxidation catalysts are the foci. The data will be useful to designers of AR systems for future flexible path missions. This is a continuation of work presented in a prior year, with extended test results.

Evaluation of Commercial Off-the-Shelf Sorbents and Catalysts for Control of Ammonia and Carbon Monoxide

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Somi, George; Winchester, J. Parker; Grose, Jeffrey; Mulloth, Lila; Perry, Jay L.

2013-01-01

Designers of future space vehicles envision simplifying the Atmosphere Revitalization (AR) system by combining the functions of trace contaminant (TC) control and carbon dioxide removal into one swing-bed system. Flow rates and bed sizes of the TC and CO2 systems have historically been very different. There is uncertainty about the ability of trace contaminant sorbents to adsorb adequately in high-flow or short bed length configurations, and to desorb adequately during short vacuum exposures. There is also concern about ambient ammonia levels in the absence of a condensing heat exchanger. In addition, new materials and formulations have become commercially available, formulations never evaluated by NASA for purposes of trace contaminant control. The optimal air revitalization system for future missions may incorporate a swing-bed system for carbon dioxide (CO2) and partial trace contaminant control, with a reduced-size, low-power, targeted trace contaminant system supplying the remaining contaminant removal capability. This paper describes the results of a comparative experimental investigation into materials for trace contaminant control that might be part of such a system. Ammonia sorbents and low temperature carbon monoxide (CO) oxidation catalysts are the foci. The data will be useful to designers of AR systems for future flexible path missions. This is a continuation of work presented in a prior year, with extended test results.

Multi-Phase Extraction: State-of-the-Practice

EPA Pesticide Factsheets

This report describes the state-of-the-practice for multi-phase extraction (MPE) of contaminated soil and groundwater, focusing primarily on the application and use of MPE at sites with halogenated volatile organic compounds (VOCs).

Public health assessment for El Toro Marine Corps Air Station, Santa Ana, Orange County, California, Region 9. CERCLIS No. CA6170023208. Final report

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

Not Available

El Toro Marine Corps Air Station is in Orange County, California, near the city of Irvine. The Marine Corps established El Toro in 1943, and it currently serves as the center for marine aviation operations on the Pacific Coast. El Toro Marine Corps Air Station was proposed for listing on EPA's National Priorities List (NPL) in 1989 because past operations and disposal practices contaminated local groundwater. Agricultural farm workers and well operators are exposed to contaminants in groundwater through unintentional ingestion of contaminated groundwater, dermal contact with contaminated groundwater, and inhalation of aerosolized groundwater contaminants. Future exposure could occur throughmore » two potable water wells that are located 10 miles downgradient of the contaminant plume. At the current rate of contaminant migration, those wells will be affected in one and a half to five years.« less

Infection control in hemodialysis units: a quick access to essential elements.

PubMed

Karkar, Ayman; Bouhaha, Betty Mandin; Dammang, Mienalyn Lim

2014-05-01

Infection is the most common cause of hospitalization and the second most common cause of mortality among hemodialysis (HD) patients, after cardiovascular disease. HD patients as well as the dialysis staff are vulnerable to contracting health-care-associated infections (HAIs) due to frequent and prolonged exposure to many possible contaminants in the dialysis environment. The extracorporeal nature of the therapy, the associated common environmental conditions and the immune compromised status of HD patients are major predisposing factors. The evident increased potential for transmission of infections in the HD settings led to the creation and implementation of specific and stricter infection prevention and control measures in addition to the usual standard precautions. Different international organizations have generated guidelines and recommendations on infection prevention and control for implementation in the HD settings. These include the Centers for Disease Control and Prevention (CDC), the Association of Professionals in Infection Control (APIC), the Kidney Disease Outcomes Quality Initiative (K/DOQI), the European Best Practice Guidelines/European Renal Best Practice (EBPG/ERBP) and the Kidney Disease: Improving Global Outcomes (KDIGO). However, these guidelines are extensive and sometimes vary among different guideline-producing bodies. Our aim in this review is to facilitate the access, increase the awareness and encourage implementation among dialysis providers by reviewing, extracting and comparing the essential elements of guidelines and recommendations on infection prevention and control in HD units.

System to control contamination during retrieval of buried TRU waste

DOEpatents

Menkhaus, Daniel E.; Loomis, Guy G.; Mullen, Carlan K.; Scott, Donald W.; Feldman, Edgar M.; Meyer, Leroy C.

1993-01-01

A system to control contamination during the retrieval of hazardous waste comprising an outer containment building, an inner containment building, within the outer containment building, an electrostatic radioactive particle recovery unit connected to and in communication with the inner and outer containment buildings, and a contaminate suppression system including a moisture control subsystem, and a rapid monitoring system having the ability to monitor conditions in the inner and outer containment buildings.

System to control contamination during retrieval of buried TRU waste

DOEpatents

Menkhaus, D.E.; Loomis, G.G.; Mullen, C.K.; Scott, D.W.; Feldman, E.M.; Meyer, L.C.

1993-04-20

A system is described to control contamination during the retrieval of hazardous waste comprising an outer containment building, an inner containment building, within the outer containment building, an electrostatic radioactive particle recovery unit connected to and in communication with the inner and outer containment buildings, and a contaminate suppression system including a moisture control subsystem, and a rapid monitoring system having the ability to monitor conditions in the inner and outer containment buildings.

Environmental Verification Experiment for the Explorer Platform (EVEEP)

NASA Technical Reports Server (NTRS)

Norris, Bonnie; Lorentson, Chris

1992-01-01

Satellites and long-life spacecraft require effective contamination control measures to ensure data accuracy and maintain overall system performance margins. Satellite and spacecraft contamination can occur from either molecular or particulate matter. Some of the sources of the molecular species are as follows: mass loss from nonmetallic materials; venting of confined spacecraft or experiment volumes; exhaust effluents from attitude control systems; integration and test activities; and improper cleaning of surfaces. Some of the sources of particulates are as follows: leaks or purges which condense upon vacuum exposure; abrasion of movable surfaces; and micrometeoroid impacts. The Environmental Verification Experiment for the Explorer Platform (EVEEP) was designed to investigate the following aspects of spacecraft contamination control: materials selection; contamination modeling of existing designs; and thermal vacuum testing of a spacecraft with contamination monitors.

Use of cryopumps on large space simulation systems

NASA Technical Reports Server (NTRS)

Mccrary, L. E.

1980-01-01

The need for clean, oil free space simulation systems has demanded the development of large, clean pumping systems. The assurance of optically dense liquid nitrogen baffles over diffusion pumps prevents backstreaming to a large extent, but does not preclude contamination from accidents or a control failure. Turbomolecular pumps or ion pumps achieve oil free systems but are only practical for relatively small chambers. Large cryopumps were developed and checked out which do achieve clean pumping of very large chambers. These pumps can be used as the original pumping system or can be retrofitted as a replacement for existing diffusion pumps.

Auditing Operating Room Recycling: A Management Case Report.

PubMed

McGain, Forbes; Jarosz, Katherine Maria; Nguyen, Martin Ngoc Hoai Huong; Bates, Samantha; O'Shea, Catherine Jane

2015-08-01

Much waste arises from operating rooms (ORs). We estimated the practical and financial feasibility of an OR recycling program, weighing all waste from 6 ORs in Melbourne, Australia. Over 1 week, 237 operations produced 1265 kg in total: general waste 570 kg (45%), infectious waste 410 kg (32%), and recyclables 285 kg (23%). The achieved recycling had no infectious contamination. The achieved recycling/potential recycling rate was 285 kg/517 kg (55%). The average waste disposal costs were similar for general waste and recycling. OR recycling rates of 20%-25% total waste were achievable without compromising infection control or financial constraints.

Payload/orbiter contamination control requirement study: Spacelab configuration contamination study

NASA Technical Reports Server (NTRS)

Bareiss, L. E.; Hetrick, M. A.; Ress, E. B.; Strange, D. A.

1976-01-01

The assessment of the Spacelab carrier induced contaminant environment was continued, and the ability of Spacelab to meet established contamination control criteria for the space transportation system program was determined. The primary areas considered included: (1) updating, refining, and improving the Spacelab contamination computer model and contamination analysis methodology, (2) establishing the resulting adjusted induced environment predictions for comparison with the applicable criteria, (3) determining the Spacelab design and operational requirements necessary to meet the criteria, (4) conducting mission feasibility analyses of the combined Spacelab/Orbiter contaminant environment for specific proposed mission and payload mixes, and (5) establishing a preliminary Spacelab mission support plan as well as model interface requirements; A summary of those activities conducted to date with respect to the modelling, analysis, and predictions of the induced environment, including any modifications in approach or methodology utilized in the contamination assessment of the Spacelab carrier, was presented.

Feed contamination with Fusarium mycotoxins induces a corticosterone stress response in broiler chickens.

PubMed

Antonissen, G; De Baere, S; Devreese, M; Van Immerseel, F; Martel, A; Croubels, S

2017-01-01

The aim of the present study was to evaluate the effect of the Fusarium mycotoxins deoxynivalenol (DON) and fumonisins (FBs) on the stress response in broiler chickens, using corticosterone (CORT) in plasma as a biomarker. Chickens were fed either a control diet, a DON contaminated diet, a FBs contaminated diet, or a DON and FBs contaminated diet for 15 d at concentrations close to the European Union maximum guidance levels for DON and FBs in poultry. Mean plasma CORT levels were significantly higher in broiler chickens fed a DON contaminated and a DON and FBs contaminated diet compared to birds fed a control diet. A similar trend was observed for animals fed a FBs contaminated diet. Consequently, feeding broilers a diet contaminated with DON and/or FBs induced a CORT stress response, which may indicate a negative effect on animal welfare. © 2016 Poultry Science Association Inc.

Contamination during criminal investigation: Detecting police contamination and secondary DNA transfer from evidence bags.

PubMed

Fonneløp, Ane Elida; Johannessen, Helen; Egeland, Thore; Gill, Peter

2016-07-01

As the profiling systems used in forensic analyses have become more sensitive in recent years, the risk of detecting a contamination in a DNA sample has increased proportionally. This requires more stringent work protocols and awareness to minimize the chance of contamination. Although there is high consciousness on contamination and best practice procedures in forensic labs, the same requirements are not always applied by the police. In this study we have investigated the risk of contamination from police staff. Environmental DNA was monitored by performing wipe tests (sampling of hot spots) at two large police units (scenes of crime departments). Additionally, the DNA profiles of the scenes of crime officers were compared to casework samples that their own unit had investigated in the period of 2009-2015. Furthermore, a pilot study to assess whether DNA from the outside package of an exhibit could be transferred to a DNA sample was carried out. Environmental DNA was detected in various samples from hot spots. Furthermore, 16 incidences of previously undetected police-staff contamination were found in casework that had been submitted between 2009 and 2015. In 6 cases the police officers with a matching DNA profile reported that they had not been involved with the case. We have demonstrated that DNA from the outside package can be transferred to an exhibit during examination. This experience demonstrates that when implementing the new multiplex systems, it is important to ensure that 'best practice' procedures are upgraded, and appropriate training is provided in order to ensure that police are aware of the increased contamination risks. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Tackling the Challenge of Deep Vadose Zone Remediation at the Hanford Site

NASA Astrophysics Data System (ADS)

Morse, J. G.; Wellman, D. M.; Gephart, R.

2010-12-01

The Central Plateau of the Hanford Site in Washington State contains some 800 waste disposal sites where 1.7 trillion liters of contaminated water was once discharged into the subsurface. Most of these sites received liquids from the chemical reprocessing of spent uranium fuel to recover plutonium. In addition, 67 single shell tanks have leaked or are suspected to have leaked 3.8 million liters of high alkali and aluminate rich cesium-contaminated liquids into the sediment. Today, this inventory of subsurface contamination contains an estimated 550,000 curies of radioactivity and 150 million kg (165,000 tons) of metals and hazardous chemicals. Radionuclides range from mobile 99Tc to more immobilized 137Cs, 241Am, uranium, and plutonium. A significant fraction of these contaminants likely remain within the deep vadose zone. Plumes of groundwater containing tritium, nitrate, 129I and other contaminants have migrated through the vadose zone and now extend outward from the Central Plateau to the Columbia River. During most of Hanford Site history, subsurface studies focused on groundwater monitoring and characterization to support waste management decisions. Deep vadose zone studies were not a priority because waste practices relied upon that zone to buffer contaminant releases into the underlying aquifer. Remediation of the deep vadose zone is now central to Hanford Site cleanup because these sediments can provide an ongoing source of contamination to the aquifer and therefore to the Columbia River. However, characterization and remediation of the deep vadose zone pose some unique challenges. These include sediment thickness; contaminant depth; coupled geohydrologic, geochemical, and microbial processes controlling contaminant spread; limited availability and effectiveness of traditional characterization tools and cleanup remedies; and predicting contaminant behavior and remediation performance over long time periods and across molecular to field scales. The U.S Department of Energy recognizes these challenges and is committed to a sustained, focused effort of continuing to apply existing technologies where feasible while investing and developing in new innovative, field-demonstrated capabilities supporting longer-term basic and applied research to establish the technical underpinning for solving intractable deep vadose zone problems and implementing final remedies. This approach will rely upon Multi-Project Teams focusing on coordinated projects across multiple DOE offices, programs, and site contractors plus the facilitation of basic and applied research investments through implementing a Deep Vadose Zone Applied Field Research Center and other scientific studies.

Relationships between groundwater contamination and major-ion chemistry in a karst aquifer

NASA Astrophysics Data System (ADS)

Scanlon, B. R.

1990-11-01

Groundwater contamination was examined within a rural setting of the Inner Bluegrass Karst Region of central Kentucky where potential contaminant sources include soil-organic matter, organic and inorganic fertilizer, and septic-tank effluent. To evaluate controls on groundwater contamination, data on nitrate concentrations and indicator bacteria in water from wells and springs were compared with physical and chemical attributes of the groundwater system. Bacterial densities greater than the recommended limit were found in all springs and approximately half of the wells, whereas nitrate concentrations >45 mg l -1 were restricted to 20% of the springs and 10% of the wells. Nitrate concentrations varied markedly in closely spaced wells and springs, which indicates that land use is not the primary control on groundwater contamination. Groundwater contamination is related to the distribution of chemical water types in the study area. All Ca subtype water was contaminated with nitrate and bacteria. Ca subtype water occurs in the shallow, rapidly circulating groundwater zone, which is most susceptible to contamination. The similarity in nitrate concentrations between local springs, major springs, and wells that contain Ca subtype water indicates that the occurrence of large conduits is not the main control on nitrate and bacterial contamination of groundwater. Temporal fluctuations in nitrate concentrations of Ca subtype water are attributed to seasonal fluctuations in recharge and in plant growth. Ca-Mg water subtype was generally not contaminated, and Na-HCO 3 and Na-Cl water types were not contaminated. Ca-Mg water subtype, and Na-HCO 3 and Na-Cl water types are associated with longer residence times and reducing conditions, which allow bacterial die-off and denitrification, respectively. Differences in residence time and reducing conditions among the chemical water types and subtypes are attributed to variations in rock permeability and to the occurrence of horizontal shales that control the rate and depth of active groundwater circulation. This relationship between chemical water types and contaminant concentrations is important for groundwater monitoring programs and the siting of waste-disposal facilities.

A Pilot Assessment of Occupational Health Hazards in the US Electronic Scrap Recycling Industry

PubMed Central

Ceballos, Diana M.; Gong, Wei; Page, Elena

2015-01-01

The National Institute for Occupational Safety and Health (NIOSH) surveyed a randomly selected sample of electronic scrap (e-scrap) recycling facilities nationwide to characterize work processes, exposures, and controls. Despite multiple attempts to contact 278 facilities, only 47 responded (17% response rate). Surveyed facilities reported recycling a wide variety of electronics. The most common recycling processes were manual dismantling and sorting. Other processes included shredding, crushing, and automated separation. Many facilities reported that they had health and safety programs in place. However, some facilities reported the use of compressed air for cleaning, a practice that can lead to increased employee dust exposures, and some facilities allowed food and drinks in the production areas, a practice that can lead to ingestion of contaminants. Although our results may not be generalizable to all US e-scrap recycling facilities, they are informative regarding health and safety programs in the industry. We concluded that e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the frequent use of manual processes. On-site evaluations of e-scrap recyclers are needed to determine if reported work processes, practices, and controls are effective and meet current standards and guidelines. Educating the e-scrap recycling industry about health and safety best practices, specifically related to safe handling of metal dust, would help protect employees. PMID:25738822

A Pilot Assessment of Occupational Health Hazards in the US Electronic Scrap Recycling Industry.

PubMed

Ceballos, Diana M; Gong, Wei; Page, Elena

2015-01-01

The National Institute for Occupational Safety and Health (NIOSH) surveyed a randomly selected sample of electronic scrap (e-scrap) recycling facilities nationwide to characterize work processes, exposures, and controls. Despite multiple attempts to contact 278 facilities, only 47 responded (17% response rate). Surveyed facilities reported recycling a wide variety of electronics. The most common recycling processes were manual dismantling and sorting. Other processes included shredding, crushing, and automated separation. Many facilities reported that they had health and safety programs in place. However, some facilities reported the use of compressed air for cleaning, a practice that can lead to increased employee dust exposures, and some facilities allowed food and drinks in the production areas, a practice that can lead to ingestion of contaminants. Although our results may not be generalizable to all US e-scrap recycling facilities, they are informative regarding health and safety programs in the industry. We concluded that e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the frequent use of manual processes. On-site evaluations of e-scrap recyclers are needed to determine if reported work processes, practices, and controls are effective and meet current standards and guidelines. Educating the e-scrap recycling industry about health and safety best practices, specifically related to safe handling of metal dust, would help protect employees.

Evaluating best practices for Campylobacter and Salmonella reduction in poultry processing plants.

PubMed

Wideman, N; Bailey, M; Bilgili, S F; Thippareddi, H; Wang, L; Bratcher, C; Sanchez-Plata, M; Singh, M

2016-02-01

Poultry processing plants in the United States were surveyed on their current Campylobacter and Salmonella control practices. Following surveys, data were collected to develop a baseline for prevalence rates of Salmonella and Campylobacter; then changes in practices were implemented and evaluated for improvements in pathogen control. Surveys were sent to the plant Quality Assurance managers to determine production levels, antimicrobial interventions, and current pathogen testing practices. Initial sampling was performed at 6 plants with similar production volumes, at sites that included carcass samples before any pre-evisceration intervention, after exiting the inside-outside bird washer (IOBW), after exiting the pre-chiller, after exiting the primary chiller, and after exiting any post-chill intervention, as well as a water sample from each scalder, pre-chiller, primary chiller, and post-chill dip tank or finishing chiller. Enumerations and enrichments were performed for Campylobacter and Salmonella. Following the baseline sampling, changes in practices were suggested for each plant and a second sampling was conducted to determine their effectiveness. Results demonstrated that peracetic acid (PAA) was the most effective (P < 0.05) antimicrobial currently in use. The use of a post-chill antimicrobial immersion tank and/or use of a cetylpyridinium chloride (CPC) spray cabinet also displayed a further reduction in microbial levels (P < 0.05) when the primary chiller was not sufficient (P > 0.05). Microbial buildup in the immersion tanks demonstrates the need for effective cleaning, sanitation practices, and chiller maintenance to reduce contamination of poultry with Campylobacter and Salmonella. © 2015 Poultry Science Association Inc.

Airborne emissions of carcinogens and respiratory sensitizers during thermal processing of plastics.

PubMed

Unwin, John; Coldwell, Matthew R; Keen, Chris; McAlinden, John J

2013-04-01

Thermoplastics may contain a wide range of additives and free monomers, which themselves may be hazardous substances. Laboratory studies have shown that the thermal decomposition products of common plastics can include a number of carcinogens and respiratory sensitizers, but very little information exists on the airborne contaminants generated during actual industrial processing. The aim of this work was to identify airborne emissions during thermal processing of plastics in real-life, practical applications. Static air sampling was conducted at 10 industrial premises carrying out compounding or a range of processes such as extrusion, blown film manufacture, vacuum thermoforming, injection moulding, blow moulding, and hot wire cutting. Plastics being processed included polyvinyl chloride, polythene, polypropylene, polyethylene terephthalate, and acrylonitrile-butadiene-styrene. At each site, static sampling for a wide range of contaminants was carried out at locations immediately adjacent to the prominent fume-generating processes. The monitoring data indicated the presence of few carcinogens at extremely low concentrations, all less than 1% of their respective WEL (Workplace Exposure Limit). No respiratory sensitizers were detected at any sites. The low levels of process-related fume detected show that the control strategies, which employed mainly forced mechanical general ventilation and good process temperature control, were adequate to control the risks associated with exposure to process-related fume. This substantiates the advice given in the Health and Safety Executive's information sheet No 13, 'Controlling Fume During Plastics Processing', and its broad applicability in plastics processing in general.

Green Remediation Best Management Practices: Overview of EPA's Methodology to Address the Environmental Footprint of Site Cleanup

EPA Pesticide Factsheets

Contaminated site cleanups involving complex activities may benefit from a detailed environmental footprint analysis to inform decision-making about application of suitable best management practices for greener cleanups.

Gonadal steroidogenesis in vitro from juvenile alligators obtained from contaminated or control lakes.

PubMed Central

Guillette, L J; Gross, T S; Gross, D A; Rooney, A A; Percival, H F

1995-01-01

The ubiquitous distribution of many contaminants and the nonlethal, multigenerational effects of such contaminants on reproductive, endocrine, and immune systems have led to concerns that wildlife worldwide are affected. Although the causal agents and effects are known for some species, the underlying physiological mechanisms associated with contaminant-induced reproductive modifications are still poorly understood and require extensive research. We describe a study examining the steroidogenic activity of gonads removed from juvenile alligators (Alligator mississippiensis) obtained from contaminated or control lakes in central Florida. Synthesis of estradiol-17 beta (E2) was significantly different when ovaries from the contaminated and control lakes were compared in vitro. Additionally, testes from males obtained from the contaminated lake. Lake Apopka, synthesized significantly higher concentrations of E2 when compared to testes obtained from control males. In contrast, testosterone (T) synthesis from all testes examined in this study displayed a normal pattern and produced concentrations greater than that observed from ovaries obtained from either lake. Interestingly, the pattern of gonadal steroidogenesis differs from previously reported plasma concentrations of these hormones obtained from the same individuals. We suggest that the differences between the in vivo and in vitro patterns are due to modifications in the hepatic degradation of plasma sex steroid hormones. PMID:7556021

Cosmet'eau-Changes in the personal care product consumption practices: from whistle-blowers to impacts on aquatic environments.

PubMed

Bressy, Adèle; Carré, Catherine; Caupos, Émilie; de Gouvello, Bernard; Deroubaix, José-Frédéric; Deutsch, Jean-Claude; Mailler, Romain; Marconi, Anthony; Neveu, Pascale; Paulic, Laurent; Pichon, Sébastien; Rocher, Vincent; Severin, Irina; Soyer, Mathilde; Moilleron, Régis

2016-07-01

The Cosmet'eau project (2015-2018) investigates the "changes in the personal care product (PCP) consumption practices: from whistle-blowers to impacts on aquatic environments." In this project, the example of PCPs will be used to understand how public health concerns related to micropollutants can be addressed by public authorities-including local authorities, industries, and consumers. The project aims to characterize the possible changes in PCP consumption practices and to evaluate the impact of their implementation on aquatic contamination. Our goals are to study the whistle-blowers, the risk perception of consumers linked with their practices, and the contamination in parabens and their substitutes, triclosan, and triclocarban from wastewater to surface water. The project investigates the following potential solutions: modifications of industrial formulation or changes in consumption practices. The final purpose is to provide policy instruments for local authorities aiming at building effective strategies to fight against micropollutants in receiving waters.

SIX YEARS OF INTENSIVE MONITORING OF THE 1ST PRB TO TREAT A MIXED WASTE PLUME: USCG SITE IN ELIZABETH CITY, NC

EPA Science Inventory

Permeable reactive barriers (PRBs) for the restoration of contaminated ground water are no longer innovative. PRBs have evolved from innovative to accepted, standard practice, for the containment and treatment of a variety of contaminants in ground water. Like any remedial tech...

Ecosystem recovery following selenium contamination in a freshwater reservoir

Treesearch

A. Dennis Lemly

1997-01-01

Belews Lake, North Carolina, was contaminated by selenium in wastewater released from a coal-fired electric generating facility during 1974-1985. Selenium bioaccumulated in aquatic food chains and caused severe reproductive failure and teratogenic deformities in fish. Beginning in 1986, the electric utility company changed its ash disposal practices and selenium-laden...

PERFORMANCE OF AIR SPARGING AND SOIL VACUUM EXTRACTION FOR TREATMENT OF MTBE AND BENZENE AT UST SITES IN KANSAS

EPA Science Inventory

The efficacy of soil vacuum extraction or air sparging and soil vacuum extraction for remediation of ground water contamination with MTBE was compared to remediation of contamination with benzene. There was no practical difference.
Sites were identified that met the followin...

21 CFR 111.365 - What precautions must you take to prevent contamination?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false What precautions must you take to prevent contamination? 111.365 Section 111.365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN...

The reactive bed plasma system for contamination control

NASA Technical Reports Server (NTRS)

Birmingham, Joseph G.; Moore, Robert R.; Perry, Tony R.

1990-01-01

The contamination control capabilities of the Reactive Bed Plasma (RBP) system is described by delineating the results of toxic chemical composition studies, aerosol filtration work, and other testing. The RBP system has demonstrated its capabilities to decompose toxic materials and process hazardous aerosols. The post-treatment requirements for the reaction products have possible solutions. Although additional work is required to meet NASA requirements, the RBP may be able to meet contamination control problems aboard the Space Station.

Review: Nutritional ecology of heavy metals.

PubMed

Hejna, M; Gottardo, D; Baldi, A; Dell'Orto, V; Cheli, F; Zaninelli, M; Rossi, L

2018-01-08

The aim of this review is to focus the attention on the nutrition ecology of the heavy metals and on the major criticisms related to the heavy metals content in animal feeds, manure, soil and animal-origin products. Heavy metals are metallic elements that have a high density that have progressively accumulated in the food chain with negative effects for human health. Some metals are essential (Fe, I, Co, Zn, Cu, Mn, Mo, Se) to maintain various physiological functions and are usually added as nutritional additives in animal feed. Other metals (As, Cd, F, Pb, Hg) have no established biological functions and are considered as contaminants/undesirable substances. The European Union adopted several measures in order to control their presence in the environment, as a result of human activities such as: farming, industry or food processing and storage contamination. The control of the animal input could be an effective strategy to reduce human health risks related to the consumption of animal-origin products and the environmental pollution by manure. Different management of raw materials and feed, animal species as well as different legal limits can influence the spread of heavy metals. To set up effective strategies against heavy metals the complex interrelationships in rural processes, the widely variability of farming practices, the soil and climatic conditions must be considered. Innovative and sustainable approaches have discussed for the heavy metal nutrition ecology to control the environmental pollution from livestock-related activities.

NV/YMP radiological control manual, Revision 2

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

Gile, A.L.

The Nevada Test Site (NTS) and the adjacent Yucca Mountain Project (YMP) are located in Nye County, Nevada. The NTS has been the primary location for testing nuclear explosives in the continental US since 1951. Current activities include operating low-level radioactive and mixed waste disposal facilities for US defense-generated waste, assembly/disassembly of special experiments, surface cleanup and site characterization of contaminated land areas, and non-nuclear test operations such as controlled spills of hazardous materials at the hazardous Materials (HAZMAT) Spill Center (HSC). Currently, the major potential for occupational radiation exposure is associated with the burial of low-level nuclear waste andmore » the handling of radioactive sources. Planned future remediation of contaminated land areas may also result in radiological exposures. The NV/YMP Radiological Control Manual, Revision 2, represents DOE-accepted guidelines and best practices for implementing Nevada Test Site and Yucca Mountain Project Radiation Protection Programs in accordance with the requirements of Title 10 Code of Federal Regulations Part 835, Occupational Radiation Protection. These programs provide protection for approximately 3,000 employees and visitors annually and include coverage for the on-site activities for both personnel and the environment. The personnel protection effort includes a DOE Laboratory Accreditation Program accredited dosimetry and personnel bioassay programs including in-vivo counting, routine workplace air sampling, personnel monitoring, and programmatic and job-specific As Low as Reasonably Achievable considerations.« less

The mouse mammary gland as a sentinel organ: distinguishing 'control' populations with diverse environmental histories.

PubMed

Kolla, SriDurgaDevi; Pokharel, Aastha; Vandenberg, Laura N

2017-03-09

There are numerous examples of laboratory animals that were inadvertently exposed to endocrine disrupting chemicals (EDCs) during the process of conducting experiments. Controlling contaminations in the laboratory is challenging, especially when their source is unknown. Unfortunately, EDC contaminations can interfere with the interpretation of data during toxicological evaluations. We propose that the male CD-1 mouse mammary gland is a sensitive bioassay to evaluate the inadvertent contamination of animal colonies. We evaluated mammary glands collected from two CD-1 mouse populations with distinct environmental histories. Population 1 was born and raised in a commercial laboratory with unknown EDC exposures; Population 2 was the second generation raised in an animal facility with limited exposures to xenoestrogens from caging, feed, etc. Mammary glands were collected from all animals and evaluated using morphometric techniques to quantify morphological characteristics of the mammary gland. Population 1 (with suspected history of environmental chemical exposure) and Population 2 (with known limited history of xenoestrogen exposure) were morphologically distinguishable in adult males, prepubertal females, and pubertal females. Mammary glands from males raised in the commercial animal facility were significantly more developed, with larger ductal trees and more branching points. The appearance of these mammary glands was consistent with prior reports of male mice exposed to low doses of bisphenol A (BPA) during early development. In females, the two populations were morphologically distinct at both prepuberty and puberty, with the most striking differences observed in the number, size, and density of terminal end buds, e.g. highly proliferative structures found in the developing mammary gland. Collectively, these results suggest that the mouse mammary gland has the potential to be used as a sentinel organ to evaluate and distinguish animal colonies raised in different environmental conditions including potential EDC exposures. Our findings could help researchers that wish to perform a posteriori evaluations to determine whether inadvertent contamination with xenoestrogens (and potentially other EDCs) has occurred in their animal colonies, especially after new materials (feed, caging, water bottles) have been introduced. Finally, our results challenge the relatively common practice of using historical controls in toxicological experiments.

Pooling raw shell eggs: Salmonella contamination and high risk practices in the United Kingdom food service sector.

PubMed

Gormley, F J; Little, C L; Murphy, N; de Pinna, E; McLauchlin, J

2010-03-01

Salmonella contamination of pooled raw shelled egg mix (RSEM) used as an ingredient in lightly cooked or uncooked foods and high-risk kitchen hygiene practices in United Kingdom food service establishments using RSEM were investigated. Samples were collected from 934 premises. Salmonella was found in 1 (0.13%) of 764 RSEM samples, 2 (0.3%) of 726 samples from surfaces where ready-to-eat foods were prepared, and 7 (1.3%) of 550 cleaning cloths. Poor RSEM storage and handling practices were highlighted. Workers in 40% of the premises sampled failed to use designated utensils when RSEM was added to other ingredients, workers in 17% of the premises did not clean surfaces and utensils thoroughly after use with RSEM and before preparing other foods, only 42% of workers washed and dried their hands after handling eggs or RSEM, workers in 41% of the premises did not store RSEM at refrigeration temperature before use, and workers in 8% of the premises added RSEM to cooked rice at the end of cooking when preparing egg fried rice. Take-away premises, especially those serving Chinese cuisine, were least likely to have a documented food safety management system and awareness of the key food safety points concerning the use of RSEM compared with other food service premises (P < 0.0001). Food service businesses using RSEM must be aware of the continuing hazard from Salmonella, must adopt appropriate control measures, and must follow advice provided by national food agencies to reduce the risk of Salmonella infection.

Untangling the web of European regulations for the preparation of unlicensed radiopharmaceuticals: a concise overview and practical guidance for a risk-based approach.

PubMed

Lange, Rogier; ter Heine, Rob; Decristoforo, Clemens; Peñuelas, Iván; Elsinga, Philip H; van der Westerlaken, Monique M L; Hendrikse, N Harry

2015-05-01

Radiopharmaceuticals are highly regulated, because they are controlled both as regular medicinal products and as radioactive substances. This can pose a hurdle for their development and clinical use. Radiopharmaceuticals are fundamentally different from other medicinal products and these regulations are not always adequate for their production. Strict compliance may have a huge resource impact, without further improving product quality. In this paper we give an overview of the applicable legislation and guidelines and propose a risk-based approach for their implementation. We focus on a few controversial Good Manufacturing Practice topics: cleanroom classification, air pressure regime, cleanroom qualification and microbiological monitoring. We have developed an algorithm to assess the combined risk of microbiological contamination of a radiopharmaceutical preparation process and propose corresponding Good Manufacturing Practice classification levels. In our opinion, the risk of carry-over of radiopharmaceuticals by individuals cannot be contained by pressure differences, and complicated regimes with underpressured rooms are not necessary in most situations. We propose a sterility assurance level of 10 for radiopharmaceuticals that are administered within a working day, irrespective of their use. We suggest the adoption of limits for environmental monitoring of microbial contamination, as proposed by Bruel and colleagues, on behalf of the French Society of Radiopharmacy. Recently launched regulatory documents seem to breathe a more liberal spirit than current legislation and recognize the need for the use of risk assessment. We argue that future legislation be further harmonized and state risk assessment as the gold standard for implementation of drug quality regulations for the preparation of unlicensed radiopharmaceuticals.

Comparison of food safety cognitions and self-reported food-handling behaviors with observed food safety behaviors of young adults.

PubMed

Abbot, J M; Byrd-Bredbenner, C; Schaffner, D; Bruhn, C M; Blalock, L

2009-04-01

Developing tailored and effective food safety education for young adults is critical given their future roles as caregivers likely to be preparing food for populations who may be at greater risk for foodborne disease (FBD). The objective of this study was to examine the relationship between food safety self-reported food-handling behaviors and cognitions of young adults to observed food-handling behaviors. Participants were 153 young adults (mean age 20.74+/-1.30 s.d.) attending a major American university. Each prepared a meal under observation in a controlled laboratory setting, permitted researchers to observe their home kitchen and completed an online survey assessing food safety knowledge, behavior and psychosocial measures. Descriptive statistics were generated for participants' self-reported food-handling behaviors, psychosocial characteristics, knowledge, food preparation observations and home kitchen observations. Determinants of compliance with safe food-handling procedures while preparing a meal and home food storage/rotation practices were identified using backward regression models. Participants engaged in less than half of the recommended safe food-handling practices evaluated and correctly answered only two-thirds of the food safety knowledge items. They reported positive food safety beliefs and high food safety self-efficacy. Self-reported compliance with cross-contamination prevention, disinfection procedures and knowledge of groups at greatest risk for FBD were the best measures for predicting compliance with established safe food-handling practices. Food safety education directed toward young adults should focus on increasing awareness of FBD and knowledge of proper cross-contamination prevention procedures to help promote better compliance with actual safe food handling.

Making Child Care Centers SAFER: A Non-Regulatory Approach to Improving Child Care Center Siting

PubMed Central

Somers, Tarah S; Harvey, Margaret L.; Rusnak, Sharee Major

2011-01-01

Licensed child care centers are generally considered to be safe because they are required to meet state licensing regulations. As part of their licensing requirements, many states inspect child care centers and include an assessment of the health and safety of the facility to look for hazardous conditions or practices that may harm children. However, most states do not require an environmental assessment of the child care center building or land to prevent a center from being placed on, next to, or inside contaminated buildings. Having worked on several sites where child care centers were affected by environmental contaminants, the Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry (ATSDR) endeavor to raise awareness of this issue. One of ATSDR's partner states, Connecticut, took a proactive, non-regulatory approach to the issue with the development its Child Day Care Screening Assessment for Environmental Risk Program. PMID:21563710

An outbreak of hepatitis A associated with a bakery, New York, 1994: the 1968 "West Branch, Michigan' outbreak repeated.

PubMed Central

Weltman, A. C.; Bennett, N. M.; Ackman, D. A.; Misage, J. H.; Campana, J. J.; Fine, L. S.; Doniger, A. S.; Balzano, G. J.; Birkhead, G. S.

1996-01-01

In a community hepatitis A outbreak in the Rochester, New York area, 64 of 79 (81%) people with anti-hepatitis A IgM-antibodies and onset of symptoms from 9 April-31 May 1994, recalled eating food obtained from a retail buyer's club. Eleven (65%) of 17 households with cases contained club members compared with 7 (21%) of 34 neighbourhood-matched control-households (matched odds ratio 8.5; 95% CI 1.7-41.6). Club employees who ate sugar-glazed baked goods were at fourfold increased risk for hepatitis. The source of infection was an IgM-positive baker who contaminated baked goods while applying sugar glaze. Computer-generated purchase lists implicated 11-12 March and 21-24 March as the most likely dates when contamination occurred. This investigation demonstrates the importance of food workers adhering to established hygiene practices. Computer-generated commercial datasets can be useful in epidemiologic investigations. PMID:8870631

Hemodialysis and Water Quality

PubMed Central

Coulliette, Angela D.; Arduino, Matthew J.

2015-01-01

Over 383,900 individuals in the U.S. undergo maintenance hemodialysis that exposes them to water, primarily in the form of dialysate. The quality of water and associated dialysis solutions have been implicated in adverse patient outcomes and is therefore critical. The Association for the Advancement of Medical Instrumentation has published both standards and recommended practices that address both water and the dialyzing solutions. Some of these recommendations have been adopted into Federal Regulations by the Centers for Medicare and Medicaid Services as part of the Conditions for Coverage, which includes limits on specific contaminants within water used for dialysis, dialysate, and substitution fluids. Chemical, bacterial, and endotoxin contaminants are health threats to dialysis patients, as shown by the continued episodic nature of outbreaks since the 1960s causing at least 592 cases and 16 deaths in the U.S. The importance of the dialysis water distribution system, current standards and recommendations, acceptable monitoring methods, a review of chemical, bacterial, and endotoxin outbreaks, and infection control programs are discussed. PMID:23859187

Temporal-Spatial Evolution of Groundwater Nitrogen Pollution Over Seven Years in a Highly Urbanized City in the Southern China.

PubMed

He, Xiaorui; Qian, Jiazhong; Liu, Zufa; Lu, Yuehan; Ma, Lei; Zhao, Weidong; Kang, Bo

2017-12-01

Understanding the temporospatial variation in nitrogen pollution in groundwater and the associated controlling factors is important to establish management practices that ensure sustainable use of groundwater. In this study, we analyzed inorganic nitrogen content (nitrate, nitrite, and ammonium) in 1164 groundwater samples from shallow, middle-deep, and deep aquifers in Zhanjiang, a highly urbanized city in the southern China. Our data span a range of 7 years from 2005 to 2011. Results show that shallow aquifers had been heavily contaminated by nitrate and ammonium. Temporal patterns show that N contamination levels remained high and relatively stable over time in urban areas. This stability and high concentration is hypothesized as a result of uncontrolled, illicit sewer discharges from nearby business facilities. Groundwater in urban land and farmland displays systematic differences in geochemical characteristics. Collectively, our findings demonstrate the importance of continuously monitoring groundwater quality and strictly regulating sewage discharges in Zhanjiang.

[Research advances in eco-toxicological diagnosis of soil pollution].

PubMed

Liu, Feng; Teng, Hong-Hui; Ren, Bai-Xiang; Shi, Shu-Yun

2014-09-01

Soil eco-toxicology provides a theoretical basis for ecological risk assessment of contaminated soils and soil pollution control. Research on eco-toxicological effects and molecular mechanisms of toxic substances in soil environment is the central content of the soil eco-toxicology. Eco-toxicological diagnosis not only gathers all the information of soil pollution, but also provides the overall toxic effects of soil. Therefore, research on the eco-toxicological diagnosis of soil pollution has important theoretical and practical significance. Based on the research of eco-toxicological diagnosis of soil pollution, this paper introduced some common toxicological methods and indicators, with the advantages and disadvantages of various methods discussed. However, conventional biomarkers can only indicate the class of stress, but fail to explain the molecular mechanism of damage or response happened. Biomarkers and molecular diagnostic techniques, which are used to evaluate toxicity of contaminated soil, can explore deeply detoxification mechanisms of organisms under exogenous stress. In this paper, these biomarkers and techniques were introduced systematically, and the future research trends were prospected.

Noise suppression methods for robust speech processing

NASA Astrophysics Data System (ADS)

Boll, S. F.; Ravindra, H.; Randall, G.; Armantrout, R.; Power, R.

1980-05-01

Robust speech processing in practical operating environments requires effective environmental and processor noise suppression. This report describes the technical findings and accomplishments during this reporting period for the research program funded to develop real time, compressed speech analysis synthesis algorithms whose performance in invariant under signal contamination. Fulfillment of this requirement is necessary to insure reliable secure compressed speech transmission within realistic military command and control environments. Overall contributions resulting from this research program include the understanding of how environmental noise degrades narrow band, coded speech, development of appropriate real time noise suppression algorithms, and development of speech parameter identification methods that consider signal contamination as a fundamental element in the estimation process. This report describes the current research and results in the areas of noise suppression using the dual input adaptive noise cancellation using the short time Fourier transform algorithms, articulation rate change techniques, and a description of an experiment which demonstrated that the spectral subtraction noise suppression algorithm can improve the intelligibility of 2400 bps, LPC 10 coded, helicopter speech by 10.6 point.

Avian influenza: public health and food safety concerns.

PubMed

Chmielewski, Revis; Swayne, David E

2011-01-01

Avian influenza (AI) is a disease or asymptomatic infection caused by Influenzavirus A. AI viruses are species specific and rarely cross the species barrier. However, subtypes H5, H7, and H9 have caused sporadic infections in humans, mostly as a result of direct contact with infected birds. H5N1 high pathogenicity avian influenza (HPAI) virus causes a rapid onset of severe viral pneumonia and is highly fatal (60% mortality). Outbreaks of AI could have a severe economic and social impact on the poultry industry, trade, and public health. Surveillance data revealed that H5N1 HPAI has been detected in imported frozen duck meat from Asia, and on the surface and in contaminated eggs. However, there is no direct evidence that AI viruses can be transmitted to humans via the consumption of contaminated poultry products. Implementing management practices that incorporate biosecurity principles, personal hygiene, and cleaning and disinfection protocols, as well as cooking and processing standards, are effective means of controlling the spread of the AI viruses.

Fetal Tissues Tested for Microbial Sterility by Culture- and PCR-Based Methods Can be Safely Used in Clinics.

PubMed

Vitrenko, Yakov; Kostenko, Iryna; Kulebyakina, Kateryna; Duda, Alla; Klunnyk, Mariya; Sorochynska, Khrystyna

2017-02-16

Cell preparations to be used in clinical practice must be free of infectious agents. Safety concerns are especially elevated upon the use of human fetal tissues, which are otherwise highly advantageous in cell therapy. We demonstrate that treating fetal samples with antibiotic, extensive washing, and homogenization prior to cryoconservation efficiently removes microbes in general. Screening a large collection by an automatic culture system showed that 89.2% fetal tissue samples were sterile, while contamination was detected in 10.8% samples. Liver and chorion were contaminated more than the brain, kidney, lung, and soft tissues. Broad-range PCR from the bacterial 16s rRNA gene was adopted as a confirmatory assay; however, the concordance between the culture-based and PCR assays was weak. Taxonomic identification was done for contaminated samples by bacteriological methods and sequencing 16s rRNA PCR products. The two approaches revealed different spectra of taxonomic groups sharing only Lactobacillus, the most frequently found genus. In addition, other representatives of vaginal microbiota were detected by culture-based identification, while PCR product sequencing has also revealed a subset of nosocomial microorganisms. Importantly, species known to cause sepsis were identified by both techniques, arguing for their indispensability and mutual complementarity. We suggest that most contaminations are taken up during collection of fetal material rather than originating from an in utero infection. In conclusion, a rigorous microbiological control by culture and PCR is a prerequisite for safe clinical use of fetal tissue suspensions.

Modeling bacterial contamination of fuel ethanol fermentation.

PubMed

Bischoff, Kenneth M; Liu, Siqing; Leathers, Timothy D; Worthington, Ronald E; Rich, Joseph O

2009-05-01

The emergence of antibiotic-resistant bacteria may limit the effectiveness of antibiotics to treat bacterial contamination in fuel ethanol plants, and therefore, new antibacterial intervention methods and tools to test their application are needed. Using shake-flask cultures of Saccharomyces cerevisiae grown on saccharified corn mash and strains of lactic acid bacteria isolated from a dry-grind ethanol facility, a simple model to simulate bacterial contamination and infection was developed. Challenging the model with 10(8) CFU/mL Lactobacillus fermentum decreased ethanol yield by 27% and increased residual glucose from 6.2 to 45.5 g/L. The magnitude of the effect was proportional to the initial bacterial load, with 10(5) CFU/mL L. fermentum still producing an 8% decrease in ethanol and a 3.2-fold increase in residual glucose. Infection was also dependent on the bacterial species used to challenge the fermentation, as neither L. delbrueckii ATCC 4797 nor L. amylovorus 0315-7B produced a significant decrease in ethanol when inoculated at a density of 10(8) CFU/mL. In the shake-flask model, treatment with 2 microg/mL virginiamycin mitigated the infection when challenged with a susceptible strain of L. fermentum (MIC for virginiamycin < or =2 ppm), but treatment was ineffective at treating infection by a resistant strain of L. fermentum (MIC = 16 ppm). The model may find application in developing new antibacterial agents and management practices for use in controlling contamination in the fuel ethanol industry. Copyright 2008 Wiley Periodicals, Inc.

RESEARCH & DEVELOPMENT OF PREVENTION AND CONTROL MEASURES FOR MOLD CONTAMINATION

EPA Science Inventory

The U.S. Environmental Protection Agency, Air Pollution Prevention and Control Division, Indoor Environment Management Branch has, since 1995, conducted research into controlling biological contamination in the indoor environment. In this paper four areas of research are discusse...

Trends in blood culture contamination: a College of American Pathologists Q-Tracks study of 356 institutions.

PubMed

Bekeris, Leonas G; Tworek, Joseph A; Walsh, Molly K; Valenstein, Paul N

2005-10-01

Blood culture contamination extends hospital stays and increases the cost of care. To measure blood culture contamination rates in a large number of institutions over time and to elucidate practice patterns and demographic factors associated with sustained reduction in contamination rates. Longitudinal cohort study of 356 clinical laboratories that provided quarterly data about blood culture results, using a uniform definition of contamination. Mixed linear model analysis of the 1999 through 2003 data set. Blood culture contamination was significantly higher in institutions that used nonlaboratory personnel to collect blood (P = .03) and significantly lower in facilities that used a dedicated phlebotomy team (P < .001). Higher volume of blood collection was significantly associated with lower contamination rates (P < .001). Continued participation in the Q-Tracks monitoring program was associated with significant and progressive reduction in contamination rates. By the fifth year of participation, the median institution had reduced its blood culture contamination rate by 0.67% (P < .001). Institutions that use decentralized patient-centered personnel rather than dedicated phlebotomy teams to collect blood cultures experience significantly higher contamination rates. Long-term monitoring of contamination is associated with sustained improvement in performance.

Contamination Control Changes to the Reusable Solid Rocket Motor Program: A Ten Year Review

NASA Technical Reports Server (NTRS)

Bushman, David M.

1998-01-01

During the post Challenger period, the National Aeronautics and Space Administration and Thiokol implemented changes to the Reusable Solid Rocket Motor (RSRM) contract to include provisions for contamination control to enhance the production environment. During the ten years since those agreements for contamination controls were made, many changes have taken place in the production facilities at Thiokol. These changes have led to the production of much higher quality shuttle solid rocket motors and improved cleanliness and safety of operations in the production facilities. The experience in contamination control over this past decade highlights the value these changes have brought to the RSRM program, and how the system can be improved to meet the challenges the program will face in the next ten years.

Chinese proprietary medicine in Singapore: regulatory control of toxic heavy metals and undeclared drugs.

PubMed

Koh, H L; Woo, S O

2000-11-01

Traditional Chinese medicine (TCM) is gaining popularity as a form of complementary and alternative medicine. Reports of efficacy of TCM are increasing in numbers. TCM includes both crude Chinese medicinal materials (plants, animal parts and minerals) and Chinese proprietary medicine (CPM) [final dosage forms]. Despite the belief that CPM and herbal remedies are of natural origin, unlike Western medicine, and are hence safe and without many adverse effects, there have been numerous reports of adverse effects associated with herbal remedies. Factors affecting the safety of herbal medicines include intrinsic toxicity, adulteration, substitution, contamination, misidentification, lack of standardisation, incorrect preparation and/or dosage and inappropriate labelling and/or advertising. Hence, new regulations on the control of CPM were enforced in Singapore with effect from 1 September 1999. These include licensing and labelling requirements, as well as control of microbial contamination. This article also reviews reports of excessive toxic heavy metals and undeclared drugs in CPM in Singapore between 1990 and 1997. The names, uses, toxic heavy metal or drug detected and the year of detection are tabulated. Information on the brand or manufacturer's name are provided whenever available. The public and healthcare professionals should be better informed of the basic concept of TCM and its usefulness, as well as the potential adverse effects associated with its use. Greater control over the safety and quality of CPM could be achieved through good manufacturing practice, regulatory control, research, education, reporting usage of Chinese medicine (as in drug history) as well as reporting of adverse events.

Use of rotifers for the maintenance of monoalgal mass cultures of Spirulina

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

Mitchell, S.A.; Richmond, A.

1987-01-01

Zooplankton was successfully used for the biological control of unicellular algal contaminants in Spirulina mass cultures even under conditions adverse to the growth of Spirulina (maximal winter daily temperature of approximately 10 degrees C and very low bicarbonate concentration). Brachionus plicatilis (Rotifera) was the most successful species of zooplankton used. The interrelationships between Spirulina, green unicellular contaminant, and B. plicatilis were studied under various conditions. Two species of unicellular contaminant were used; Monoraphidium minutum was isolated from local cultures and Chlorella vulgaris, obtained from contaminated Spirulina cultures in Israel. The rotifer B. plicatilis successfully controlled the population size of bothmore » contaminants whether they were introduced in a single addition or as a daily dose. The biological control of the unicellular contaminants allows Spirulina to be cultured in a medium low in bicarbonate, thereby reducing the cost of the medium and increasing the quantity of CO2 that may be freely absorbed from the atmosphere at the optimal pH for Spirulina cultivation. (Refs. 9).« less

Sterility of pediatric lipid emulsions repackaged by an automated compounding device.

PubMed

Ybarra, Joseph V; Rose, Warren E; Curtis, Caitlin S; Sacks, Gordon S

2011-05-01

The daily requirement of intravenous (IV) lipid in pediatric patients is often less than the volumes and sizes available in prepackaged, commercially available preparations. In clinical practice, IV lipid emulsions (IVLEs) have been repackaged into syringes to prevent infusions from exceeding 12 hours, to reduce waste, and to improve patient safety. Recent data suggest an increasing risk of contamination when these preparations are repackaged manually. This study investigates the sterility of small volumes of IVLE that have been repackaged into empty IV bags by means of an automated compounding device (ACD). A total of 152 IVLE bags were repackaged with an ACD in an International Standards Organization class 5 environment. IVLE repackaging was conducted over a period of 3 weeks (week 1, n = 52; week 2, n = 52; week 3, n = 48). Forty commercially available bags of IVLE served as controls. At 0, 24, 48, and 120 hours after repackaging, IVLEs were filtered and placed onto blood agar medium. Microbial growth occurred in 12 of the 152 repackaged preparations compared with 0 of the 40 controls (7.9% vs 0%, P = .07). Positive cultures consisted of gram-positive cocci (n = 5, 3.3%), gram-positive rods (n = 5, 3.3%), and yeast (n = 2, 1.3%). There was no difference in positive bacterial or yeast growth between weeks 1, 2, and 3, suggesting an absence of outside contamination during preparation. The positive microbial growth suggests a concerning incidence of contamination of IVLEs repackaged with an ACD. Additional research is needed to further identify and validate the clinical impact of these preparations.

IMPACT OF REDOX DISEQUILIBRIA ON CONTAMINANT TRANSPORT AND REMEDIATION IN SUBSURFACE SYSTEMS

EPA Science Inventory

Partitioning to mineral surfaces exerts significant control on inorganic contaminant transport in subsurface systems. Remedial technologies for in-situ treatment of subsurface contamination are frequently designed to optimize the efficiency of contaminant partitioning to solid s...

Evolution of Toxoplasma-PCR methods and practices: a French national survey and proposal for technical guidelines.

PubMed

Roux, Guillaume; Varlet-Marie, Emmanuelle; Bastien, Patrick; Sterkers, Yvon

2018-06-08

The molecular diagnosis of toxoplasmosis lacks standardisation due to the use of numerous methods with variable performance. This diversity of methods also impairs robust performance comparisons between laboratories. The harmonisation of practices by diffusion of technical guidelines is a useful way to improve these performances. The knowledge of methods and practices used for this molecular diagnosis is an essential step to provide guidelines for Toxoplasma-PCR. In the present study, we aimed (i) to describe the methods and practices of Toxoplasma-PCR used by clinical microbiology laboratories in France and (ii) to propose technical guidelines to improve molecular diagnosis of toxoplasmosis. To do so, a yearly self-administered questionnaire-based survey was undertaken in proficient French laboratories from 2008 to 2015, and guidelines were proposed based on the results of those as well as previously published work. This period saw the progressive abandonment of conventional PCR methods, of Toxoplasma-PCR targeting the B1 gene and of the use of two concomitant molecular methods for this diagnosis. The diversity of practices persisted during the study, in spite of the increasing use of commercial kits such as PCR kits, DNA extraction controls and PCR inhibition controls. We also observed a tendency towards the automation of DNA extraction. The evolution of practices did not always go together with an improvement in those, as reported notably by the declining use of Uracil-DNA Glycosylase to avoid carry-over contamination. We here propose technical recommendations which correspond to items explored during the survey, with respect to DNA extraction, Toxoplasma-PCR and good PCR practices. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Escherichia coli O157:H7 infections associated with consumption of locally grown strawberries contaminated by deer.

PubMed

Laidler, Matthew R; Tourdjman, Mathieu; Buser, Genevieve L; Hostetler, Trevor; Repp, Kimberly K; Leman, Richard; Samadpour, Mansour; Keene, William E

2013-10-01

An outbreak of Escherichia coli O157:H7 was identified in Oregon through an increase in Shiga toxin-producing E. coli cases with an indistinguishable, novel pulsed-field gel electrophoresis (PFGE) subtyping pattern. We defined confirmed cases as persons from whom E. coli O157:H7 with the outbreak PFGE pattern was cultured during July-August 2011, and presumptive cases as persons having a household relationship with a case testing positive for E. coli O157:H7 and coincident diarrheal illness. We conducted an investigation that included structured hypothesis-generating interviews, a matched case-control study, and environmental and traceback investigations. We identified 15 cases. Six cases were hospitalized, including 4 with hemolytic uremic syndrome (HUS). Two cases with HUS died. Illness was significantly associated with strawberry consumption from roadside stands or farmers' markets (matched odds ratio, 19.6; 95% confidence interval, 2.9-∞). A single farm was identified as the source of contaminated strawberries. Ten of 111 (9%) initial environmental samples from farm A were positive for E. coli O157:H7. All samples testing positive for E. coli O157:H7 contained deer feces, and 5 tested farm fields had ≥ 1 sample positive with the outbreak PFGE pattern. The investigation identified fresh strawberries as a novel vehicle for E. coli O157:H7 infection, implicated deer feces as the source of contamination, and highlights problems concerning produce contamination by wildlife and regulatory exemptions for locally grown produce. A comprehensive hypothesis-generating questionnaire enabled rapid identification of the implicated product. Good agricultural practices are key barriers to wildlife fecal contamination of produce.

Tritium contamination at EG&G/EM in North Las Vegas, Nevada

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

Sowell, C.V.; Arent, L.J.

1996-06-01

The tritium contamination discovered at the EG&G Energy Measurements (EG&G/EM) facility in North Las Vegas, Nevada, on 20 April 1995, could have been averted by good health physics practices and/or adequate management oversight. Scandium tritide (ScT{sub 3}) targets were installed for use in sealed tube neutron generators at EG&G/EM. In addition, EG&G/EM was also storing zirconium tritide (ZrT{sub 3}) and titanium tritide (TiT{sub 3}) foils. Since the targets were classified as sealed sources, the appropriate administrative and engineering control measures such as relocating targets/sources, air monitoring, bioassay, waste stream management, labeling/posting and training were not implemented. In all there weremore » six unreported incidents of tritium contamination from March 1994 to July 1995. Swipe surveys revealed areas exceeding the action level of 10,000 dpm/100 cm{sup 2} by up to three orders of magnitude. After reclassifying the targets as unsealed sources, a bioassay program was instituted, and the results were higher than expected for three employees. The doses assigned to the three individuals working in the contaminated area were 35, 58, and 61 mrem committed effective dose equivalent. Though the doses were low, the decontamination costs were in excess of $350,000.00. An investigation, was initiated by the U.S. Department of Energy Nevada Operations Office to analyze the events that led to the tritium contamination and recommend actions to prevent recurrence. Event and causal factor charting, Project Evaluation Tree (PET) analysis techniques, and root cause analysis, were used to evaluate management systems, causal sequences, and systems factors contributing to the tritium release.« less

Freshwater Vulnerability to Nitrate Contamination as an Indicator of Sustainability and Resilience within the Water-Energy-Food Nexus of the California Coastal Basins

NASA Astrophysics Data System (ADS)

Nanus, L.; Geyer, G.; Gurdak, J. J.; Orencio, P. M.; Endo, A.; Taniguchi, M.

2014-12-01

The California Coastal Basin (CCB) aquifers are representative of many coastal aquifers that are vulnerable to nonpoint-source (NPS) contamination from intense agriculture and increased urbanization combined with historical groundwater use and overdraft conditions. Overdraft has led to seawater intrusion along parts of the central California coast, which negatively affects food production because of high salinity concentrations in groundwater used for irrigation. Recent drought conditions in California have led to an increased need to further understand freshwater sustainability and resilience within the water-energy-food (WEF) nexus. Assessing the vulnerability of NPS contamination in groundwater provides valuable information for optimal resource management and policy. Vulnerability models of nitrate contamination in the CCB were developed as one of many indicators to evaluate risk in terms of susceptibility of the physical environment at local and regional scales. Multivariate logistic regression models were developed to predict the probability of NPS nitrate contamination in recently recharged groundwater and to identify significant explanatory variables as controlling factors in the CCB. Different factors were found to be significant in the sub-regions of the CCB and issues of scale are important. For example, land use is scale dependent because of the difference in land management practices between the CCB sub-regions. However, dissolved oxygen concentrations in groundwater, farm fertilizer, and soil thickness are scale invariant because they are significant both regionally and sub-regionally. Thus, the vulnerability models for the CCB show that different explanatory variables are scale invariant. This finding has important implications for accurately quantifying linkages between vulnerability and consequences within the WEF nexus, including inherent tradeoffs in water and food production in California and associated impacts on the local and regional economy, governance, environment, and society at multiple scales.

Potential value of phosphate compounds in enhancing immobilization and reducing bioavailability of mixed heavy metal contaminants in shooting range soil.

PubMed

Seshadri, B; Bolan, N S; Choppala, G; Kunhikrishnan, A; Sanderson, P; Wang, H; Currie, L D; Tsang, Daniel C W; Ok, Y S; Kim, G

2017-10-01

Shooting range soils contain mixed heavy metal contaminants including lead (Pb), cadmium (Cd), and zinc (Zn). Phosphate (P) compounds have been used to immobilize these metals, particularly Pb, thereby reducing their bioavailability. However, research on immobilization of Pb's co-contaminants showed the relative importance of soluble and insoluble P compounds, which is critical in evaluating the overall success of in situ stabilization practice in the sustainable remediation of mixed heavy metal contaminated soils. Soluble synthetic P fertilizer (diammonium phosphate; DAP) and reactive (Sechura; SPR) and unreactive (Christmas Island; CPR) natural phosphate rocks (PR) were tested for Cd, Pb and Zn immobilization and later their mobility and bioavailability in a shooting range soil. The addition of P compounds resulted in the immobilization of Cd, Pb and Zn by 1.56-76.2%, 3.21-83.56%, and 2.31-74.6%, respectively. The reactive SPR significantly reduced Cd, Pb and Zn leaching while soluble DAP increased their leachate concentrations. The SPR reduced the bioaccumulation of Cd, Pb and Zn in earthworms by 7.13-23.4% and 14.3-54.6% in comparison with earthworms in the DAP and control treatment, respectively. Bioaccessible Cd, Pb and Zn concentrations as determined using a simplified bioaccessibility extraction test showed higher long-term stability of P-immobilized Pb and Zn than Cd. The differential effect of P-induced immobilization between P compounds and metals is due to the variation in the solubility characteristics of P compounds and nature of metal phosphate compounds formed. Therefore, Pb and Zn immobilization by P compounds is an effective long-term remediation strategy for mixed heavy metal contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Probability-based nitrate contamination map of groundwater in Kinmen.

PubMed

Liu, Chen-Wuing; Wang, Yeuh-Bin; Jang, Cheng-Shin

2013-12-01

Groundwater supplies over 50% of drinking water in Kinmen. Approximately 16.8% of groundwater samples in Kinmen exceed the drinking water quality standard (DWQS) of NO3 (-)-N (10 mg/L). The residents drinking high nitrate-polluted groundwater pose a potential risk to health. To formulate effective water quality management plan and assure a safe drinking water in Kinmen, the detailed spatial distribution of nitrate-N in groundwater is a prerequisite. The aim of this study is to develop an efficient scheme for evaluating spatial distribution of nitrate-N in residential well water using logistic regression (LR) model. A probability-based nitrate-N contamination map in Kinmen is constructed. The LR model predicted the binary occurrence probability of groundwater nitrate-N concentrations exceeding DWQS by simple measurement variables as independent variables, including sampling season, soil type, water table depth, pH, EC, DO, and Eh. The analyzed results reveal that three statistically significant explanatory variables, soil type, pH, and EC, are selected for the forward stepwise LR analysis. The total ratio of correct classification reaches 92.7%. The highest probability of nitrate-N contamination map presents in the central zone, indicating that groundwater in the central zone should not be used for drinking purposes. Furthermore, a handy EC-pH-probability curve of nitrate-N exceeding the threshold of DWQS was developed. This curve can be used for preliminary screening of nitrate-N contamination in Kinmen groundwater. This study recommended that the local agency should implement the best management practice strategies to control nonpoint nitrogen sources and carry out a systematic monitoring of groundwater quality in residential wells of the high nitrate-N contamination zones.

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.

Construction, Part of Indoor Air Quality Design Tools for Schools

EPA Pesticide Factsheets

Poor job-site construction practices can frustrate even the best design by allowing moisture and other contaminants to become potential long term problems. Preventive job-site practices will reduce the potential for residual problems with IAQ

AGRICULTURAL DRAINAGE WELLS: IMPACT ON GROUND WATER

EPA Science Inventory

This document discusses agricultural drainage well practices, potential contamination problems that may occur, and possible management practices or regulatory solutions that could be used to alleviate those problems. The document has been written for use by state and Agency deci...

Using spacecraft trace contaminant control systems to cure sick building syndrome

NASA Technical Reports Server (NTRS)

Graf, John C.

1994-01-01

Many residential and commercial buildings with centralized, recirculating, heating ventilation and air conditioning systems suffer from 'Sick Building Syndrome.' Ventilation rates are reduced to save energy costs, synthetic building materials off-gas contaminants, and unsafe levels of volatile organic compounds (VOC's) accumulate. These unsafe levels of contaminants can cause irritation of eyes and throat, fatigue and dizziness to building occupants. Increased ventilation, the primary method of treating Sick Building Syndrome is expensive (due to increased energy costs) and recently, the effectiveness of increased ventilation has been questioned. On spacecraft venting is not allowed, so the primary methods of air quality control are; source control, active filtering, and destruction of VOC's. Four non-venting contaminant removal technologies; strict material selection to provide source control, ambient temperature catalytic oxidation, photocatalytic oxidation, and uptake by higher plants, may have potential application for indoor air quality control.

A Bayesian geostatistical approach for evaluating the uncertainty of contaminant mass discharges from point sources

NASA Astrophysics Data System (ADS)

Troldborg, M.; Nowak, W.; Binning, P. J.; Bjerg, P. L.

2012-12-01

Estimates of mass discharge (mass/time) are increasingly being used when assessing risks of groundwater contamination and designing remedial systems at contaminated sites. Mass discharge estimates are, however, prone to rather large uncertainties as they integrate uncertain spatial distributions of both concentration and groundwater flow velocities. For risk assessments or any other decisions that are being based on mass discharge estimates, it is essential to address these uncertainties. We present a novel Bayesian geostatistical approach for quantifying the uncertainty of the mass discharge across a multilevel control plane. The method decouples the flow and transport simulation and has the advantage of avoiding the heavy computational burden of three-dimensional numerical flow and transport simulation coupled with geostatistical inversion. It may therefore be of practical relevance to practitioners compared to existing methods that are either too simple or computationally demanding. The method is based on conditional geostatistical simulation and accounts for i) heterogeneity of both the flow field and the concentration distribution through Bayesian geostatistics (including the uncertainty in covariance functions), ii) measurement uncertainty, and iii) uncertain source zone geometry and transport parameters. The method generates multiple equally likely realizations of the spatial flow and concentration distribution, which all honour the measured data at the control plane. The flow realizations are generated by analytical co-simulation of the hydraulic conductivity and the hydraulic gradient across the control plane. These realizations are made consistent with measurements of both hydraulic conductivity and head at the site. An analytical macro-dispersive transport solution is employed to simulate the mean concentration distribution across the control plane, and a geostatistical model of the Box-Cox transformed concentration data is used to simulate observed deviations from this mean solution. By combining the flow and concentration realizations, a mass discharge probability distribution is obtained. Tests show that the decoupled approach is both efficient and able to provide accurate uncertainty estimates. The method is demonstrated on a Danish field site contaminated with chlorinated ethenes. For this site, we show that including a physically meaningful concentration trend and the co-simulation of hydraulic conductivity and hydraulic gradient across the transect helps constrain the mass discharge uncertainty. The number of sampling points required for accurate mass discharge estimation and the relative influence of different data types on mass discharge uncertainty is discussed.

Multiscale Structure of UXO Site Characterization: Spatial Estimation and Uncertainty Quantification

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

Ostrouchov, George; Doll, William E.; Beard, Les P.

2009-01-01

Unexploded ordnance (UXO) site characterization must consider both how the contamination is generated and how we observe that contamination. Within the generation and observation processes, dependence structures can be exploited at multiple scales. We describe a conceptual site characterization process, the dependence structures available at several scales, and consider their statistical estimation aspects. It is evident that most of the statistical methods that are needed to address the estimation problems are known but their application-specific implementation may not be available. We demonstrate estimation at one scale and propose a representation for site contamination intensity that takes full account of uncertainty,more » is flexible enough to answer regulatory requirements, and is a practical tool for managing detailed spatial site characterization and remediation. The representation is based on point process spatial estimation methods that require modern computational resources for practical application. These methods have provisions for including prior and covariate information.« less

Mobile phones in clinical practice: reducing the risk of bacterial contamination.

PubMed

Mark, D; Leonard, C; Breen, H; Graydon, R; O'Gorman, C; Kirk, S

2014-09-01

Mobile smart phones have become increasingly integrated into the practice of doctors and allied medical professionals. Recent studies suggest them to represent reservoirs for pathogens with potential to cause nosocomial infections. This study aimed to investigate the level of contamination on phones used on surgical wards and identify strategies for their safe use within clinical areas. Fifty mobile phones were taken from members of the multidisciplinary team working in a surgical unit. Phones were swabbed by two trained investigators using a standardised technique and samples streaked out using an automated specimen inoculator onto two types of culture media (Columbia blood agar and MacConkey agar). Colonies were identified and counted by a single trained investigator in a blinded fashion. Simultaneously a questionnaire investigating usage levels of phones was given to 150 healthcare workers. Sixty per cent of phones sampled had some form of contaminant isolated from their phone. Thirty-one (62%) of phones had only three colonies or less isolated on medium. No pathogenic or drug resistant strains of bacteria were identified. A total of 88% of individuals sampled by questionnaire used their phone within the workplace of which 55% used it for clinical purposes. Sixty-three per cent expected there to be some form of contaminant on their phone with only 37% admitting to cleaning it regularly. Seventy-five per cent of people did not view a ban on phones as a practical solution was they found to be an infection risk. Touch screen smart phones may be used safely in a clinical environment, with a low risk of cross-contamination of nosocomial bacteria to patients, in the setting of effective adherence to hand hygiene policies. © 2014 John Wiley & Sons Ltd.

Assessment of groundwater vulnerability in the Daule aquifer, Ecuador, using the susceptibility index method.

PubMed

Ribeiro, Luís; Pindo, Juan Carlos; Dominguez-Granda, Luis

2017-01-01

The Guayas region in Ecuador is economically very important, producing 68% of the national crops. The main agricultural activities threaten the groundwater therein with nitrate contamination given the large fertiliser and water needs. The present work tests the applicability of the susceptibility index assessment method in evaluating the impact of agricultural activities on groundwater quality, using as a case study an aquifer of the Guayas river basin in Ecuador. The index adapts four parameters of the DRASTIC method and incorporated a new land use parameter. Results show that the areas highly vulnerable to contamination are located in irrigation perimeters of dominant paddy fields associated with the high recharge rates in the alluvial deposits. Respectively, moderately vulnerable and low-vulnerability areas correspond to aquatic environments and forests, semi-natural zones and water bodies. One of the main contributions of the Daule aquifer vulnerability is likely its wide, flat topography. A great part of the aquifer is at high risk of contamination by nitrates if a code of good agricultural practices is not applied. Therefore the implementation of a monitoring network to control the nitrates concentrations is the first step to assure groundwater quality for drinking purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Residues of legacy organochlorine contaminants in the milk of Alpine and Saanen goats from the central region of Mexico.

PubMed

Schettino, Beatriz; Gutiérrez, Rey; Ortiz, Rutilio; Vega, Salvador; Urban, Georgina; Ramírez, Acacia

2013-08-01

This study investigated a suite of legacy organochlorine contaminants in the milk of two breeds of goats raised in the central region of Mexico, where this agricultural production is of national (Mexican) economic importance. Forty milk samples from Alpine and Saanen goats were assessed. It was found that the concentrations of the majority of organochlorine pesticides in milk samples were lower than those stipulated in Mexican and international regulation. The values in both breeds of goat exceeded the upper permissible limits of Codex Alimentarius for delta hexachloro cyclohexane (HCH) (17.3 of samples of Saanen) and heptachlor plus heptachlor epoxide (50 % and 13 % of samples). It may be concluded that milk from these goat breeds from central Mexico showed some risks of contamination in certain times of the year (dry season). However, under further assessment and use of pesticides the goat's milk will likely be safe for human consumption and for use in products such as cheeses, regional candies and desserts (cajeta). In recent years, goat milk production has increased in the central regions and it is an economic alternative to milk from livestock. It is necessary to continue the monitoring of goat's milk to assess the presence and control of HCHs through best management practices.

Resistivity profiling for mapping gravel layers that may control contaminant migration at the Amargosa Desert Research Site, Nevada

USGS Publications Warehouse

Lucius, Jeffrey E.; Abraham, Jared D.; Burton, Bethany L.

2008-01-01

Gaseous contaminants, including CFC 113, chloroform, and tritiated compounds, move preferentially in unsaturated subsurface gravel layers away from disposal trenches at a closed low-level radioactive waste-disposal facility in the Amargosa Desert about 17 kilometers south of Beatty, Nevada. Two distinct gravel layers are involved in contaminant transport: a thin, shallow layer between about 0.5 and 2.2 meters below the surface and a layer of variable thickness between about 15 and 30 meters below land surface. From 2003 to 2005, the U.S. Geological Survey used multielectrode DC and AC resistivity surveys to map these gravel layers. Previous core sampling indicates the fine-grained sediments generally have higher water content than the gravel layers or the sediments near the surface. The relatively higher electrical resistivity of the dry gravel layers, compared to that of the surrounding finer sediments, makes the gravel readily mappable using electrical resistivity profiling. The upper gravel layer is not easily distinguished from the very dry, fine-grained deposits at the surface. Two-dimensional resistivity models, however, clearly identify the resistive lower gravel layer, which is continuous near the facility except to the southeast. Multielectrode resistivity surveys provide a practical noninvasive method to image hydrogeologic features in the arid environment of the Amargosa Desert.

Sensor array for the detection of organic and inorganic contaminants in post-consumer recycled plastics for food contact.

PubMed

Davis, Nathan; Danes, Jeffrey E; Vorst, Keith

2017-10-01

Post-consumer recycled (PCR) plastic material is made by collecting used plastic products (e.g., bottles and other plastic packaging materials) and reprocessing them into solid-state pellets or flakes. Plastic recycling has positive environmental benefits, but may also carry potential drawbacks due to unwanted organic and inorganic contaminants. These contaminants can migrate into food packaging made from these recycled plastic materials. The purpose of this research was to identify economically viable real-time monitoring technologies that can be used during the conversion of virgin and recycled resin feedstocks (i.e., various blends of virgin pellets and recycled solid-state pellet or mechanically ground flake) to final articles to ensure the safety, quality and sustainability of packaging feedstocks. Baseline analysis (validation) of real-time technologies was conducted using industry-standard practices for polymer analysis. The data yielded supervised predictive models developed by training sessions completed in a controlled laboratory setting. This technology can be employed to evaluate compliance and aid converters in commodity sourcing of resin without exceeding regulatory thresholds. Furthermore, this technology allowed for real-time decision and diversion strategies during the conversion of resin and flake to final articles or products to minimise the negative impact on human health and environmental exposure.

Occurrence and diversity of both bacterial and fungal communities in dental unit waterlines subjected to disinfectants.

PubMed

Costa, Damien; Mercier, Anne; Gravouil, Kevin; Lesobre, Jérôme; Verdon, Julien; Imbert, Christine

2016-10-01

Chemical disinfectants are widely advocated to reduce the microbial contamination in dental unit waterlines (DUWL). However, until now their efficacy has been poorly examined after long-term application. In this study, through quantitative PCR and high-throughput sequencing, both bacterial and fungal communities were profiled from 8- to 12-year-old DUWL treated with disinfectants commonly used by European dentists. Water was collected from the tap water supplying units to the output exposure point of the turbine handpiece following a stagnation period and dental care activity. Results showed that (i) the unit itself is the principal source of microbial contamination and (ii) water stagnation, DU maintenance practices and quality of water supplying DU appeared as parameters driving the water quality. Despite disinfecting treatment combined to flushing process, the microbial contamination remained relevant in the studied output water, in association with a high bacterial and fungal diversity. The occurrence of potentially pathogenic microorganisms in these treated DUWL demonstrated a potential infectious risk for both patients and dental staff. A disinfectant shock before a prolonged stagnation period could limit the microbial proliferation inside DUWL. Necessity to proceed to regular water quality control of DUWL was highlighted. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Numerical Simulation of Potential Groundwater Contaminant Pathways from Hydraulically Fractured Oil Shale in the Nevada Basin and Range Province

NASA Astrophysics Data System (ADS)

Rybarski, S.; Pohll, G.; Pohlmann, K.; Plume, R.

2014-12-01

In recent years, hydraulic fracturing (fracking) has become an increasingly popular method for extraction of oil and natural gas from tight formations. Concerns have been raised over a number of environmental risks associated with fracking, including contamination of groundwater by fracking fluids, upwelling of deep subsurface brines, and methane migration. Given the potentially long time scale for contaminant transport associated with hydraulic fracturing, numerical modeling remains the best practice for risk assessment. Oil shale in the Humboldt basin of northeastern Nevada has now become a target for hydraulic fracturing operations. Analysis of regional and shallow groundwater flow is used to assess several potential migration pathways specific to the geology and hydrogeology of this basin. The model domain in all simulations is defined by the geologic structure of the basin as determined by deep oil and gas well bores and formation outcrops. Vertical transport of gaseous methane along a density gradient is simulated in TOUGH2, while fluid transport along faults and/or hydraulic fractures and lateral flow through more permeable units adjacent to the targeted shale are modeled in FEFLOW. Sensitivity analysis considers basin, fault, and hydraulic fracturing parameters, and results highlight key processes that control fracking fluid and methane migration and time scales under which it might occur.

Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance, hematology, metabolism, and immunocompetence of turkeys.

PubMed

Girish, C K; Smith, T K; Boermans, H J; Karrow, N A

2008-03-01

An experiment was conducted to investigate the effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance, hematology, metabolism, and immunological parameters of turkeys. The efficacy of polymeric glucomannan mycotoxin adsorbent (GMA) in preventing these adverse effects was also evaluated. Three hundred 1-d-old male turkey poults were fed wheat-, corn-, and soybean meal-based starter (0 to 3 wk), grower (4 to 6 wk), developer (7 to 9 wk), and finisher (10 to 12 wk) diets formulated with uncontaminated grains, contaminated grains, and contaminated grains + 0.2% GMA. Feeding contaminated grains significantly decreased BW gains during the grower and developer phases, and GMA supplementation prevented these effects. There was no effect of diet, however, on feed intake or feed efficiency. The feeding of contaminated grains reduced total lymphocyte counts at wk 3 (P < 0.05). Dietary supplementation with GMA increased plasma total protein concentrations compared with controls and birds fed the contaminated diet. Plasma uric acid concentrations in birds fed contaminated grains were increased at the end of the experiment compared with controls, and the feeding of GMA prevented this effect. Feeding contaminated grains significantly increased the percentage of CD4(+) lymphocyte populations during wk 6; however, there was no change in the percentage of CD8(+) and B-lymphocyte populations. Contact hypersensitivity to dinitrochlorobenzene, which is a CD8(+) T cell-mediated delayed-type hypersensitivity response, was significantly decreased after 24 and 72 h by feedborne mycotoxins compared with controls. Supplementation of the contaminated diet with GMA prevented the decrease in response after 24 h. Secondary antibody (IgG titer) response against SRBC antigens (CD4(+) T cell-dependent) was significantly decreased after feeding contaminated grains compared with controls. It was concluded that turkey performance and some blood and immunological parameters were adversely affected by feedborne Fusarium mycotoxins, and GMA prevented many of these effects.

Low-Contamination Vibrating Feeder for Silicon Chips

NASA Technical Reports Server (NTRS)

Mackintosh, B. H.

1984-01-01

Vibratory feeding is method of controlling flow of small oddly shaped particles. Technique applied to other materials that require contamination control by feeding material through vibrating troughs topped by particular material.

Bioremediation of cadmium- and zinc-contaminated soil using Rhodobacter sphaeroides.

PubMed

Peng, Weihua; Li, Xiaomin; Song, Jingxiang; Jiang, Wei; Liu, Yingying; Fan, Wenhong

2018-04-01

Bioremediation using microorganisms is a promising technique to remediate soil contaminated with heavy metals. In this study, Rhodobacter sphaeroides was used to bioremediate soils contaminated with cadmium (Cd) and zinc (Zn). The study found that the treatment reduced the overall bioavailable fractions (e.g., exchangeable and carbonate bound phases) of Cd and Zn. More stable fractions (e.g., Fe-Mn oxide, organic bound, and residual phases (only for Zn)) increased after bioremediation. A wheat seedling experiment revealed that the phytoavailability of Cd was reduced after bioremediation using R. sphaeroides. After bioremediation, the exchangeable phases of Cd and Zn in soil were reduced by as much as 30.7% and 100.0%, respectively; the Cd levels in wheat leaf and root were reduced by as much as 62.3% and 47.2%, respectively. However, when the soils were contaminated with very high levels of Cd and Zn (Cd 54.97-65.33 mg kg -1 ; Zn 813.4-964.8 mg kg -1 ), bioremediation effects were not clear. The study also found that R. sphaeroides bioremediation in soil can enhance the Zn/Cd ratio in the harvested wheat leaf and root overall. This indicates potentially favorable application in agronomic practice and biofortification. Although remediation efficiency in highly contaminated soil was not significant, R. sphaeroides may be potentially and practically applied to the bioremediation of soils co-contaminated by Cd and Zn. Copyright © 2018 Elsevier Ltd. All rights reserved.

Simulation Evaluation of Pilot Inputs for Real Time Modeling During Commercial Flight Operations

NASA Technical Reports Server (NTRS)

Martos, Borja; Ranaudo, Richard; Oltman, Ryan; Myhre, Nick

2017-01-01

Aircraft dynamics characteristics can only be identified from flight data when the aircraft dynamics are excited sufficiently. A preliminary study was conducted into what types and levels of manual piloted control excitation would be required for accurate Real-Time Parameter IDentification (RTPID) results by commercial airline pilots. This includes assessing the practicality for the pilot to provide this excitation when cued, and to further understand if pilot inputs during various phases of flight provide sufficient excitation naturally. An operationally representative task was evaluated by 5 commercial airline pilots using the NASA Ice Contamination Effects Flight Training Device (ICEFTD). Results showed that it is practical to use manual pilot inputs only as a means of achieving good RTPID in all phases of flight and in flight turbulence conditions. All pilots were effective in satisfying excitation requirements when cued. Much of the time, cueing was not even necessary, as just performing the required task provided enough excitation for accurate RTPID estimation. Pilot opinion surveys reported that the additional control inputs required when prompted by the excitation cueing were easy to make, quickly mastered, and required minimal training.

A Flexible framework for forward and inverse modeling of stormwater control measures

NASA Astrophysics Data System (ADS)

Aflaki, S.; Massoudieh, A.

2016-12-01

Models that allow for design considerations of green infrastructure (GI) practices to control stormwater runoff and associated contaminants have received considerable attention in recent years. While popular, generally, the GI models are relatively simplistic. However, GI model predictions are being relied upon by many municipalities and State/Local agencies to make decisions about grey vs. green infrastructure improvement planning. Adding complexity to GI modeling frameworks may preclude their use in simpler urban planning situations. Therefore, the goal here was to develop a sophisticated, yet flexible tool that could be used by design engineers and researchers to capture and explore the effect of design factors and properties of the media used in the performance of GI systems at a relatively small scale. We deemed it essential to have a flexible GI modeling tool that is capable of simulating GI system components and specific biophysical processes affecting contaminants such as reactions, and particle-associated transport accurately while maintaining a high degree of flexibly to account for the myriad of GI alternatives. The mathematical framework for a stand-alone GI performance assessment tool has been developed and will be demonstrated. The process-based model framework developed here can be used to model a diverse range of GI practices such as green roof, retention pond, bioretention, infiltration trench, permeable pavement and other custom-designed combinatory systems. Four demonstration applications covering a diverse range of systems will be presented. The example applications include a evaluating hydraulic performance of a complex bioretention system, hydraulic analysis of porous pavement system, flow colloid-facilitated transport, reactive transport and groundwater recharge underneath an infiltration pond and finally reactive transport and bed-sediment interactions in a wetland system will be presented.

Storm water runoff for the Y-12 Plant and selected parking lots

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

Collins, E.T.

1996-01-01

A comparison of storm water runoff from the Y-12 Plant and selected employee vehicle parking lots to various industry data is provided in this document. This work is an outgrowth of and part of the continuing Non-Point Source Pollution Elimination Project that was initiated in the late 1980s. This project seeks to identify area pollution sources and remediate these areas through the Resource Conservation and Recovery Act/Comprehensive Environmental Response, Compensation, and Liability Act (RCRA/CERCLA) process as managed by the Environmental Restoration Organization staff. This work is also driven by the Clean Water Act Section 402(p) which, in part, deals withmore » establishing a National Pollutant Discharge Elimination System (NPDES) permit for storm water discharges. Storm water data from events occurring in 1988 through 1991 were analyzed in two reports: Feasibility Study for the Best Management Practices to Control Area Source Pollution Derived from Parking Lots at the DOE Y-12 Plant, September 1992, and Feasibility Study of Best Management Practices for Non-Point Source Pollution Control at the Oak Ridge Y-12 Plant, February 1993. These data consisted of analysis of outfalls discharging to upper East Fork Poplar Creek (EFPC) within the confines of the Y-12 Plant (see Appendixes D and E). These reports identified the major characteristics of concern as copper, iron, lead, manganese, mercury, nitrate (as nitrogen), zinc, biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), fecal coliform, and aluminum. Specific sources of these contaminants were not identifiable because flows upstream of outfalls were not sampled. In general, many of these contaminants were a concern in many outfalls. Therefore, separate sampling exercises were executed to assist in identifying (or eliminating) specific suspected sources as areas of concern.« less

9 CFR 318.309 - Finished product inspection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... microbiological contamination; (2) An FSIS-approved total quality control system; (3) Alternative documented... associated with microbial contamination, where there is no approved total quality control system, or where... Office of Management and Budget under control number 0583-0015) [51 FR 45619, Dec. 19, 1986, as amended...

Sequence analysis of the canine mitochondrial DNA control region from shed hair samples in criminal investigations.

PubMed

Berger, C; Berger, B; Parson, W

2012-01-01

In recent years, evidence from domestic dogs has increasingly been analyzed by forensic DNA testing. Especially, canine hairs have proved most suitable and practical due to the high rate of hair transfer occurring between dogs and humans. Starting with the description of a contamination-free sample handling procedure, we give a detailed workflow for sequencing hypervariable segments (HVS) of the mtDNA control region from canine evidence. After the hair material is lysed and the DNA extracted by Phenol/Chloroform, the amplification and sequencing strategy comprises the HVS I and II of the canine control region and is optimized for DNA of medium-to-low quality and quantity. The sequencing procedure is based on the Sanger Big-dye deoxy-terminator method and the separation of the sequencing reaction products is performed on a conventional multicolor fluorescence detection capillary electrophoresis platform. Finally, software-aided base calling and sequence interpretation are addressed exemplarily.

Developing sediment remediation goals at superfund sites based on pore water for the protection of benthic organisms from direct toxicity to non-ionic organic contaminants (presentation)

EPA Science Inventory

Passive sampling is becoming a frequently used measurement technique at Superfund sites with contaminated sediments. Passive sampling measures the concentrations of freely dissolved chemicals (Cfrees) in the sediment pore water. Cfree has been found to be a very practical means f...

PRELIMINARY SURVEY OF CHEMICAL CONTAMINANTS IN WATER, SEDIMENT, AND AQUATIC BIOTA AT SELECTED SITES IN NORTHEASTERN FLORIDA BAY AND CANAL C-111

EPA Science Inventory

Several actions are under way to alter water management capabilities and practices in south Florida in order to restore a more natural hydroperiod for the Everglades. Because relatively little research has been conducted on contaminants entering Florida Bay, we undertook a prelim...

21 CFR 111.10 - What requirements apply for preventing microbial contamination from sick or infected personnel...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false What requirements apply for preventing microbial contamination from sick or infected personnel and for hygienic practices? 111.10 Section 111.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

Assessment of Adoption Gaps in Management of Aflatoxin Contamination of Groundnut ("Arachis Hypogaea" L.)

ERIC Educational Resources Information Center

Kumar, G. D. S.; Popat, M. N.

2010-01-01

One of the major impediments for diversification of groundnut ("Arachis Hypogaea" L.) as food crop is aflatoxin contamination. The study was conducted with an objective to assess the adoption gaps in aflatoxin management practices of groundnut (AMPG) and the farmer's characteristics influencing these gaps. The study used an expost-facto…

Contamination concerns in the modular containerless processing facility

NASA Technical Reports Server (NTRS)

Seshan, P. K.; Trinh, E. H.

1989-01-01

This paper describes the problems of the control and management of contamination in the Modular Containerless Processing Facility (MCPF), that is being currently developed at the JPL for the Space Station, and in the MCPF's precursor version, called the Drop Physics Module (DPM), which will be carried aboard one or more Space Shuttle missions. Attention is given to the identification of contamination sources, their mode of transport to the sample positioned within the chamber, and the protection of the sample, as well as to the mathematical simulatiom of the contaminant transport. It is emphasized that, in order to choose and implement the most appropriate contamination control strategy for each investigator, a number of simplified mathematical simulations will have to be developed, and ground-based contamination experiments will have to be carried out with identical materials.

Influence of surface contamination on the wettability of heat transfer surfaces

DOE PAGES

Forrest, Eric Christopher; Schulze, Roland; Liu, Cheng; ...

2015-08-08

In this study, the wettability of heat transfer surfaces plays an important role in liquid–vapor phase change phenomena, including boiling incipience, the critical heat flux, the Leidenfrost transition, and condensation. The influence of adsorbed surface contamination at the nanoscale, though seldom considered, can have a profound impact on wetting behavior. This study quantitatively investigates the impact of contaminant layer thickness on wettability. Various cleaning treatments are explored on zirconium and 6061 aluminum to determine the effect on contaminant and oxide layer thickness. Angle-resolved X-ray photoelectron spectroscopy can be used to measure the thickness of oxide and contaminant layers, which ismore » then correlated to wettability by measuring the equilibrium contact angle. Results indicate that even after solvent cleaning, the contact angle of water on practical heat transfer surfaces is dominated by a hydrocarbon contaminant overlayer around five nanometers thick.« less

Influence of surface contamination on the wettability of heat transfer surfaces

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

Forrest, Eric Christopher; Schulze, Roland; Liu, Cheng

In this study, the wettability of heat transfer surfaces plays an important role in liquid–vapor phase change phenomena, including boiling incipience, the critical heat flux, the Leidenfrost transition, and condensation. The influence of adsorbed surface contamination at the nanoscale, though seldom considered, can have a profound impact on wetting behavior. This study quantitatively investigates the impact of contaminant layer thickness on wettability. Various cleaning treatments are explored on zirconium and 6061 aluminum to determine the effect on contaminant and oxide layer thickness. Angle-resolved X-ray photoelectron spectroscopy can be used to measure the thickness of oxide and contaminant layers, which ismore » then correlated to wettability by measuring the equilibrium contact angle. Results indicate that even after solvent cleaning, the contact angle of water on practical heat transfer surfaces is dominated by a hydrocarbon contaminant overlayer around five nanometers thick.« less

Phytoremediation of Metal-Contaminated Soils

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

Shtangeeva, I.; Laiho, J.V-P.; Kahelin, H.

2004-03-31

Recent concerns regarding environmental contamination have necessitated the development of appropriate technologies to assess the presence and mobility of metals in soil and estimate possible ways to decrease the level of soil metal contamination. Phytoremediation is an emerging technology that may be used to cleanup contaminated soils. Successful application of phytoremediation, however, depends upon various factors that must be carefully investigated and properly considered for specific site conditions. To efficiently affect the metal removal from contaminated soils we used the ability of plants to accumulate different metals and agricultural practices to improve soil quality and enhance plant biomass. Pot experimentsmore » were conducted to study metal transport through bulk soil to the rhizosphere and stimulate transfer of the metals to be more available for plants' form. The aim of the experimental study was also to find fertilizers that could enhance uptake of metals and their removal from contaminated soil.« less

Radioactive contamination incidents involving protective clothing

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

Reichelt, R.A.; Clay, M.E.; Eichorst, A.J.

1998-01-01

The study focuses on incidents at Department of Energy facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work, (2) working conditions, (3) type of anti-contamination material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-contamination clothing most often identified was cotton or water-resistantmore » disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled. 1 ref., 6 figs., 1 tab.« less

Post-Contamination Vapour Hazards from Military Vehicles Contaminated with Thickened and Unthickened GD

DTIC Science & Technology

1979-02-01

The residual vapour hazards from four types of military vehicles previously contaminated with either thickened or unthickened GD have been measured...magnitude of these hazards have been investigated and an assessment made of their relevance to contamination control. It was found that on permeable... contamination had been applied were ineffective in reducing the subsequent vapour hazard; the vapour hazard arising from thickened GD contamination was less

Large-scale contamination of microbial isolate genomes by Illumina PhiX control.

PubMed

Mukherjee, Supratim; Huntemann, Marcel; Ivanova, Natalia; Kyrpides, Nikos C; Pati, Amrita

2015-01-01

With the rapid growth and development of sequencing technologies, genomes have become the new go-to for exploring solutions to some of the world's biggest challenges such as searching for alternative energy sources and exploration of genomic dark matter. However, progress in sequencing has been accompanied by its share of errors that can occur during template or library preparation, sequencing, imaging or data analysis. In this study we screened over 18,000 publicly available microbial isolate genome sequences in the Integrated Microbial Genomes database and identified more than 1000 genomes that are contaminated with PhiX, a control frequently used during Illumina sequencing runs. Approximately 10% of these genomes have been published in literature and 129 contaminated genomes were sequenced under the Human Microbiome Project. Raw sequence reads are prone to contamination from various sources and are usually eliminated during downstream quality control steps. Detection of PhiX contaminated genomes indicates a lapse in either the application or effectiveness of proper quality control measures. The presence of PhiX contamination in several publicly available isolate genomes can result in additional errors when such data are used in comparative genomics analyses. Such contamination of public databases have far-reaching consequences in the form of erroneous data interpretation and analyses, and necessitates better measures to proofread raw sequences before releasing them to the broader scientific community.

30 CFR 56.5005 - Control of exposure to airborne contaminants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne contaminants... Administration. (c) When respiratory protection is used in atmospheres immediately harmful to life, the presence...

Systems and methods for dismantling a nuclear reactor

DOEpatents

Heim, Robert R; Adams, Scott Ryan; Cole, Matthew Denver; Kirby, William E; Linnebur, Paul Damon

2014-10-28

Systems and methods for dismantling a nuclear reactor are described. In one aspect the system includes a remotely controlled heavy manipulator ("manipulator") operatively coupled to a support structure, and a control station in a non-contaminated portion of a workspace. The support structure provides the manipulator with top down access into a bioshield of a nuclear reactor. At least one computing device in the control station provides remote control to perform operations including: (a) dismantling, using the manipulator, a graphite moderator, concrete walls, and a ceiling of the bioshield, the manipulator being provided with automated access to all internal portions of the bioshield; (b) loading, using the manipulator, contaminated graphite blocks from the graphite core and other components from the bioshield into one or more waste containers; and (c) dispersing, using the manipulator, dust suppression and contamination fixing spray to contaminated matter.

Catchment-scale environmental controls of sediment-associated contaminant dispersal

NASA Astrophysics Data System (ADS)

Macklin, Mark

2010-05-01

Globally river sediment associated contaminants, most notably heavy metals, radionuclides, Polychlorinated Biphenyls (PCBs), Organochlorine pesticides (OCs) and phosphorous, constitute one the most significant long-term risks to ecosystems and human health. These can impact both urban and rural areas and, because of their prolonged environmental residence times, are major sources of secondary pollution if contaminated soil and sediment are disturbed by human activity or by natural processes such as water or wind erosion. River catchments are also the primary source of sediment-associated contaminants to the coastal zone, and to the ocean, and an understanding of the factors that control contaminated sediment fluxes and delivery in river systems is essential for effective environmental management and protection. In this paper the catchment-scale controls of sediment-associated contaminant dispersal are reviewed, including climate-related variations in flooding regime, land-use change, channel engineering, restoration and flood defence. Drawing on case studies from metal mining impacted catchments in Bolivia (Río Pilcomayo), Spain (Río Guadiamar), Romania (River Tisa) and the UK (River Swale) some improved methodologies for identifying, tracing, modelling and managing contaminated river sediments are proposed that could have more general application in similarly affected river systems worldwide.

Epidemiology of hepatitis C virus exposure in Egypt: Opportunities for prevention and evaluation

PubMed Central

Miller, F DeWolfe; Elzalabany, Mahmoud S; Hassani, Sara; Cuadros, Diego F

2015-01-01

AIM: To critically evaluate the current epidemiology data on exposures, rather than infection, to hepatitis C virus (HCV) transmission and recommend epidemiologic strategies to fill gaps. METHODS: Standard methods for identifying and evaluating relevant epidemiologic literature and available data were used. RESULTS: There is a large body of literature on the epidemiology of HCV transmission in Egypt that collectively identifies ongoing iatrogenic exposures as the major driver for HCV transmission due to short comings in infection control and standard procedures. Additional epidemiologic studies on HCV transmission that requires the participation of human subject is unwarranted. Alternatively, very little literature was found on the epidemiology of exposure to HCV, infection control, and safe injection practices. The information that is available on patterns of HCV exposure shows high frequencies of inadequate infection control, problems in sterilization in health care facilities, low rates of hand washing, untrained personnel, lack of stated policies in facilities, HCV contamination of instruments and very large injection frequencies with low but very significant syringe and needle reuse. There is an important need to increase the number, size, and diversity of epidemiologic studies on HCV exposures, patterns of risk factors for infection, infection control, and safe injection practices. In addition to health care facilities evaluation, relevant knowledge attitude and practice studies are recommended. CONCLUSION: Epidemiologic methods on HCV exposure can be used to characterize the magnitude of exposures to HCV infection, target interventions to reduce exposures, and provide the best method for evaluating interventions by demonstrating the reduction of exposure to HCV infection. PMID:26668697

Legionella species colonization in cooling towers: risk factors and assessment of control measures.

PubMed

Mouchtouri, Varvara A; Goutziana, Georgia; Kremastinou, Jenny; Hadjichristodoulou, Christos

2010-02-01

Cooling towers can be colonized by Legionella spp, and inhalation of aerosols generated by their operation may cause Legionnaires' disease in susceptible hosts. Environmental investigations of Legionnaires' disease outbreaks linked with cooling towers have revealed poorly maintained systems, lack of control measures, and failure of system equipment. The purpose of this study was to identify Legionella-contaminated cooling towers, identify risk factors for contamination, and assess the effectiveness of control measures. A total of 96 cooling towers of public buildings were registered and inspected, and 130 samples were collected and microbiologically tested. Microbiological test results were associated with characteristics of cooling towers, water samples, inspection results, and maintenance practices. Of the total 96 cooling towers examined, 47 (48.9%) were colonized by Legionella spp, and 22 (22.9%) required remedial action. A total of 65 samples (50.0%) were positive (> or = 500 cfu L(-1)), and 30 (23%) were heavily contaminated (> or = 10(4) cfu L(-1)). Of the 69 isolates identified, 55 strains (79.7.%) were L pneumophila. Legionella colonization was positively associated with the absence of training on Legionella control (relative risk [RR] = 1.66; P = .02), absence of regular Legionella testing (RR = 2.07: P = .002), absence of sunlight protection (RR = 1.63: P = .02), with samples in which the free residual chlorine level in the water sample was < 0.5 mg/L (RR = 2.23; P = .01), and with total plate count (P =.001). Colonization was negatively associated with chemical disinfection (RR = 0.2; P = .0003) and with the presence of a risk assessment and management plan (RR = 0.12; P = .0005). A statistically significant higher age (P =.01) was found in legionellae-positive cooling towers (median, 17 years; interquartile range [IQR] =5.0 to 26.0 years) compared with noncolonized cooling towers (median age, 6 years; IQR =1.0 to 13.5 years). After the 22 legionellae-positive cooling towers were disinfected with chlorine, 2 (9%) of them remained positive for Legionella spp with a concentration > or = 1000 cfu L(-1). Cooling towers can be heavily colonized by Legionella spp and thus present a potential risk for infection. This study demonstrates the importance of a risk assessment and management plan. Water chlorination effectively reduces legionellae contamination. Proper training of cooling tower operators is paramount. Copyright 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Farm Management, Environment, and Weather Factors Jointly Affect the Probability of Spinach Contamination by Generic Escherichia coli at the Preharvest Stage

PubMed Central

Navratil, Sarah; Gregory, Ashley; Bauer, Arin; Srinath, Indumathi; Szonyi, Barbara; Nightingale, Kendra; Anciso, Juan; Jun, Mikyoung; Han, Daikwon; Lawhon, Sara; Ivanek, Renata

2014-01-01

The National Resources Information (NRI) databases provide underutilized information on the local farm conditions that may predict microbial contamination of leafy greens at preharvest. Our objective was to identify NRI weather and landscape factors affecting spinach contamination with generic Escherichia coli individually and jointly with farm management and environmental factors. For each of the 955 georeferenced spinach samples (including 63 positive samples) collected between 2010 and 2012 on 12 farms in Colorado and Texas, we extracted variables describing the local weather (ambient temperature, precipitation, and wind speed) and landscape (soil characteristics and proximity to roads and water bodies) from NRI databases. Variables describing farm management and environment were obtained from a survey of the enrolled farms. The variables were evaluated using a mixed-effect logistic regression model with random effects for farm and date. The model identified precipitation as a single NRI predictor of spinach contamination with generic E. coli, indicating that the contamination probability increases with an increasing mean amount of rain (mm) in the past 29 days (odds ratio [OR] = 3.5). The model also identified the farm's hygiene practices as a protective factor (OR = 0.06) and manure application (OR = 52.2) and state (OR = 108.1) as risk factors. In cross-validation, the model showed a solid predictive performance, with an area under the receiver operating characteristic (ROC) curve of 81%. Overall, the findings highlighted the utility of NRI precipitation data in predicting contamination and demonstrated that farm management, environment, and weather factors should be considered jointly in development of good agricultural practices and measures to reduce produce contamination. PMID:24509926

Viral Tracer Studies Indicate Contamination of Marine Waters by Sewage Disposal Practices in Key Largo, Florida

PubMed Central

Paul, J. H.; Rose, J. B.; Brown, J.; Shinn, E. A.; Miller, S.; Farrah, S. R.

1995-01-01

Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys. PMID:16535046

Viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, Florida.

PubMed

Paul, J H; Rose, J B; Brown, J; Shinn, E A; Miller, S; Farrah, S R

1995-06-01

Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys.

Computerized atmospheric trace contaminant control simulation for manned spacecraft

NASA Technical Reports Server (NTRS)

Perry, J. L.

1993-01-01

Buildup of atmospheric trace contaminants in enclosed volumes such as a spacecraft may lead to potentially serious health problems for the crew members. For this reason, active control methods must be implemented to minimize the concentration of atmospheric contaminants to levels that are considered safe for prolonged, continuous exposure. Designing hardware to accomplish this has traditionally required extensive testing to characterize and select appropriate control technologies. Data collected since the Apollo project can now be used in a computerized performance simulation to predict the performance and life of contamination control hardware to allow for initial technology screening, performance prediction, and operations and contingency studies to determine the most suitable hardware approach before specific design and testing activities begin. The program, written in FORTRAN 77, provides contaminant removal rate, total mass removed, and per pass efficiency for each control device for discrete time intervals. In addition, projected cabin concentration is provided. Input and output data are manipulated using commercial spreadsheet and data graphing software. These results can then be used in analyzing hardware design parameters such as sizing and flow rate, overall process performance and program economics. Test performance may also be predicted to aid test design.

Family caregivers in public tertiary care hospitals in Bangladesh: risks and opportunities for infection control.

PubMed

Islam, M Saiful; Luby, Stephen P; Sultana, Rebeca; Rimi, Nadia Ali; Zaman, Rashid Uz; Uddin, Main; Nahar, Nazmun; Rahman, Mahmudur; Hossain, M Jahangir; Gurley, Emily S

2014-03-01

Family caregivers are integral to patient care in Bangladeshi public hospitals. This study explored family caregivers' activities and their perceptions and practices related to disease transmission and prevention in public hospitals. Trained qualitative researchers conducted a total of 48 hours of observation in 3 public tertiary care hospitals and 12 in-depth interviews with family caregivers. Family caregivers provided care 24 hours a day, including bedside nursing, cleaning care, and psychologic support. During observations, family members provided 2,065 episodes of care giving, 75% (1,544) of which involved close contact with patients. We observed family caregivers washing their hands with soap on only 4 occasions. The majority of respondents said diseases are transmitted through physical contact with surfaces and objects that have been contaminated with patient secretions and excretions, and avoiding contact with these contaminated objects would help prevent disease. Family caregivers are at risk for hospital-acquired infection from their repeated exposure to infectious agents combined with their inadequate hand hygiene and knowledge about disease transmission. Future research should explore potential strategies to improve family caregivers' knowledge about disease transmission and reduce family caregiver exposures, which may be accomplished by improving care provided by health care workers. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.

Estimating aquatic toxicity as determined through laboratory tests of great lakes sediments containing complex mixtures of environmental contaminants

USGS Publications Warehouse

1996-01-01

We developed and evaluated a total toxic units modeling approach for predicting mean toxicity as measured in laboratory tests for Great Lakes sediments containing complex mixtures of environmental contaminants (e.g., polychlorinated biphenyls, polycyclic aromatic hydrocarbons, pesticides, chlorinated dioxins, and metals). The approach incorporates equilibrium partitioning and organic carbon control of bioavailability for organic contaminants and acid volatile sulfide (AVS) control for metals, and includes toxic equivalency for planar organic chemicals. A toxic unit is defined as the ratio of the estimated pore-water concentration of a contaminant to the chronic toxicity of that contaminant, as estimated by U.S. Environmental Protection Agency Ambient Water Quality Criteria (AWQC). The toxic unit models we developed assume complete additivity of contaminant effects, are completely mechanistic in form, and were evaluated without any a posteriori modification of either the models or the data from which the models were developed and against which they were tested. A linear relationship between total toxic units, which included toxicity attributable to both iron and un-ionized ammonia, accounted for about 88% of observed variability in mean toxicity; a quadratic relationship accounted for almost 94%. Exclusion of either bioavailability components (i.e., equilibrium partitioning control of organic contaminants and AVS control of metals) or iron from the model substantially decreased its ability to predict mean toxicity. A model based solely on un-ionized ammonia accounted for about 47% of the variability in mean toxicity. We found the toxic unit approach to be a viable method for assessing and ranking the relative potential toxicity of contaminated sediments.

Assessing the bioavailability and risk from metal-contaminated ...

EPA Pesticide Factsheets

Exposure to contaminated soil and dust is an important pathway in human health risk assessment. Physical and chemical characteristics, as well as biological factors, determine the bioaccessibility/bioavailability of soil and dust contaminants. Within a single sample, contamination may arise from multiple sources of toxic elements that may exist as different forms (species) which impact bioavailability. In turn, the bioaccessibility/bioavailability of soil and dust contaminants has a direct impact on human health risk assessment and risk management practices. Novel research efforts focusing on development and application of in vitro and in vivo methods to measure the bioaccessibility/bioavailability of metal contaminated soils have advanced in the past few years. The objective of this workshop was to focus on recent developments in assessing the bioaccessibility/bioavailability of arsenic contaminated soils, metal contamination in urban residences in Canada and potential children’s exposures to toxic elements in house dust, a community-based study known as the West Oakland Residential Lead Assessment , studies of the bioavailability of soil cadmium, chromium, nickel and mercury and human exposures to contaminated Brownfield soils. These presentations covered issues related to human health and bioavailability along with the most recent studies on community participation in assessing metal contamination, studies of exposures to residential contamination, and