Risk assessment, microbial

Buchanan R L, Smith J L and Long W (2000), Microbial risk assessment dose-response relations and risk characterization , International Journal of Food Microbiology, 58, 159-172. 

The risk assessment framework we have described for chemical toxicity is applicable to microbial risk assessment. Once the information is available on microbial hazards, which are for the most part acute (immediately observable) conditions resulting from acute (one-time) exposures, and their dose (pathogen count)-response characteristics, we should be ready to assess the risks associated with any dose of interest. Hazard information for the important pathogens is readily available but, as expected, their dose-response characteristics are much harder to come by. So with pathogen risk assessment we see the same types of uncertainties creeping into the framework as we have encountered for chemicals. 

A range of alternative methods exists at each tier, each with its own advantages and disadvantages. Although there is substantial experience with uncertainty analysis in some fields (e.g. climate change), it would be premature to make prescriptive recommendations on which methods to use in exposure assessment. For example, when discussing the use of probabilistic methods for microbial risk assessment, the former European Commission Scientific Steering Committee concluded that a quick harmonisation at the present state-of-... 

Whyte, W., and Eaton,T. (2004), Microbial risk assessment in pharmaceutical cleanrooms, Eur J Parenteral Pharm Sci, 9(1). 

Armstrong (USA) 2007 Quantitative microbial risk assessment (QMRA) model for Legionnaires disease at whirlpool spa Legionella Exposure estimate range (CFU/m )... 

Armstrong, T. W., and Haas, C. N. (2007). A quantitative microbial risk assessment model for Legionnaires disease Animal model selection and dose-response modeling. Risk Anal 27, 1581-1596. 

LL Gibson, JB Rose, CN Haas. Use of quantitative microbial risk assessment for evaluation of the benefits of laundry sanitation. Am J Infect Control 27(6) S34-S39, 1999. 

CN Haas, JB Rose, CP Gerba. Quantitative Microbial Risk Assessment. New York John Wiley Sons, Inc., 1999. 

Food Control. 1990-. Amsterdam Elsevier (0956-7135). Online ScienceDirect. Covers research in all aspects of food safety, such as microbial food safety and antimicrobial systems, mycotoxins, hazard analysis, HACCP and food safety objectives, risk assessment, including microbial risk assessment, quality assurance and control, food packaging and rapid methods of analysis and detection, including sensor technology. 

WestreU, T., Schormingen, C., Stenstrom, T.A., Ashbolt, NJ., 2004. QMRA (quantitative microbial risk assessment) and HACCP (hazard analysis and critical control points) for management of pathogens in wastewater and sewage sludge treatment and reuse. Water Science and Technology 2, 23—30. 

The ECPI approach has been adopted by the European Commission in their "Technical Guidance Document on the Risk Assessment of Notified New Substances" as the model for assessment of environmental exposure from additives in plastics. It is important to note, however, that due to the effect of ultraviolet degradation and microbial attack, a significant proportion of the emissions from flexible PVC consists of plasticizer degradation products. In these instances, therefore, the level of plasticizers appearing in the environment will be significantly less than indicated by the plasticizer loss data. 

Quantitative risk assessment is now used extensively for determination of chemical and microbial risks in food. This concept helps to systematically and scientifically judge whether certain hazardous compounds may reach unacceptable risk levels when ingested. Quantitative risk assessment can support both quality design and quality assurance but, we discuss it from the assurance perspective. In the past decade, much attention has been paid to assessment of microbial risks due to then-typical differences as compared to chemical risks ... 

Bioavailability of Metals, Nonmetals and Xenobiotics Immobilized on Soil Components, (4) Distribution and Activity of Biomolecules in Terrestrial Systems, (5) Interactions between Soil Microbial Biomass and Organic Matter/Nutrient Transformations, and (6) Impact of Interactions among Soil Mineral Colloids, Organic Matter and Biota on Risk Assessment and Restoration of Terrestrial Ecosystems. There were 2 plenary lectures, 9 invited speakers, 36 oral presentations and 45 posters. Dr. N. Senesi from University of Bari, Italy, presented an IUPAC lecture entitled Metal-Humic... 

In this paper I have tried to show that measurement of health benefits attributable to TSCA is not feasible. I hope that in doing so I have not belabored the obvious. For new chemicals and for most existing chemicals, prospective evaluation of health benefits to be achieved by various exposure controls will have to be based on extrapolation from microbial and animal data. However, while such extrapolation may be useful in a qualitative sense, quantitative risk assessment techniques involve considerable uncertainty, and in any case have not been developed for chronic effects other than cancer. 

Retrospective identification of risk from waterborne infectious disease is a relatively simpler task compared with carcinogenic risks. Many acute effects can be identified with proper population surveillance, related to probable origin, and quantified. Assessments of microbial risks from theoretical projections would be extremely complex. They... 

In the selection of a microbial system and bioremediation method, some examination of the degradation pathway is necessary. At a minimum, the final degradation products must be tested for toxicity and other regulatory demands for closure. Recent advances in the study of microbial metabolism of xenobiotics have identified potentially toxic intermediate products (Singleton, 1994). A regulatory agency sets treatment objectives for site remediation, and process analysis must determine whether bioremediation can meet these site objectives. Specific treatment objectives for some individual compounds have been established. In other cases total petroleum hydrocarbons total benzene, toluene, ethyl benzene, and xylene (BTEX) or total polynuclear aromatics objectives are set, while in yet others, a toxicology risk assessment must be performed. 

Gabrielson, J., Kuhn, I., Colque-Navarro, P., Hart, M., Iversen, A., McKenzie, D. and Mollby, R. (2003) Microplate-based microbial assay for risk assessment and (eco)toxic fingerprinting of chemicals,... 

Mokhtari A, Frey HC (2005) Recommended practice regarding selection of sensitivity analysis methods applied to microbial food safety process risk models. Human and Ecological Risk Assessment, 11(3) 591-605. 

Gaylor, D. W. (1995). Risk assessment for toxic chemicals in the environment. In Microbial Transformation and Degradation of Toxic Organic Chemicals, ed. L. Y. Young C. E. Cerniglia. New York Wiley-Liss, pp. 579-601. 

Microbial pesticides are evaluated for toxicity and infectivity prior to making regulatory decisions. As traditional dose-response-based risk assessments are not considered appropriate for microbial pesticides, regulatory jurisdictions do not typically require occupational and bystander exposure data. However, a small number of studies have monitored airborne concentrations (colony forming units/m ) of microbial pesticides following application (Teschke et al 2001), and the utility of these data should be considered by the regulatory community. 

The non- and mono-ortho CBs have been quantitated accurately in the principal source, namely, commercial PCB mixtures [15, 16] additional environmental sources such as incineration have been identified [17,18] their presence in every ecosystem including the pristine polar regions has been shown [19,20] estimates of their flux in air, water, soil, and the removal mechanisms such as OH reactions in atmosphere and sediment burial in rivers and oceans have been proposed [21] their microbial degradation and biotransformation in organisms have been studied [22,23] a battery of in-vitro and in-vivo bioassays using mammalian, avian, and piscian models for the benefit of risk-assessment of these CBs have been developed [24]. Studies like these in the last decade have resulted in a new awareness of these important class of industrial contaminants. 

These linear kinetic models and diffusion models of skin absorption kinetics have a number of features in common they are subject to similar constraints and have a similar theoretical basis. The kinetic models, however, are more versatile and are potentially powerful predictive tools used to simulate various aspects of percutaneous absorption. Techniques for simulating multiple-dose behavior evaporation, cutaneous metabolism, microbial degradation, and other surface-loss processes dermal risk assessment transdermal drug delivery and vehicle effects have all been described. Recently, more sophisticated approaches involving physiologically relevant perfusion-limited models for simulating skin absorption pharmacokinetics have been described. These advanced models provide the conceptual framework from which experiments may be designed to simultaneously assess the role of the cutaneous vasculature and cutaneous metabolism in percutaneous absorption. 

Application of Microbial Assay for Risk Assessment (MARA) to Evaluate Toxicity of Chemicals and Environmental Samples... 

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