Risk-assessment model

Brown, D. F., W. E. Dunn, and M. A. Lazaro, 1997a, CASRAM The Chemical Accident Stochastic Risk Assessment Model Technical Documentation, BetaVersion 0.8, ANL,... 

Carroll J, Boisson F, Teyssie J-L, et al. 1999. Distribution coefficients (Kd s) for use in risk assessment models of the Kara Sea. Appl Radiat Isot 51 121-129. 

In conclusion, there is no risk assessment model better than another. All models have their strengths and weaknesses. Many of them are focused on one particular aspect such as a single environmental compartment or in a kind of pollutant. It is important to remark that the selection of the data source is essential to obtain quality results. 

Keywords Environmental and risk assessment models, Life-cycle Impact assessment models, Physicochemical and toxicological database... 

Multimedia Agricultural Fate and Risk Assessment Model. 102... 

Apart from the risk assessment models, there exist models for assessing impacts to human health and the environment in LCA. Both tools [risk assessment and life cycle impact assessment (LCIA)] have different purposes and aims that are summarized in Table 1 [7]. 

BREEZE Risk Human health and ecological risk assessment modeling system designed... 

Analyst to conduct multipathway human health risk assessments and food-web based ecological risk assessment modeling. BREEZE risk analyst combines databases, GIS functionality, fate, transport, and exposure modeling equations into one software application... 

In addition to the models presented above, there are a number of other risk assessment models available. Table 2 briefly presents some of these models that can be used to assess the risk of human health and the environment. 

Fazil AM (2005) A primer on risk assessment modelling focus on seafood products. Food and Agriculture Organization of United Fisheries technical Paper, Rome... 

The then-current pesticide exposure data and risk assessment models failed to reflect real world exposures and risks. Deficiencies can only be rectified by carrying out cumulative risk assessments (CRA) across all... 

A ruling has been passed by the European Commission s scientific committee on toxicity, ecotoxicity and the environment, (the CSTEE), that the use of acetyl tributyl citrate as a plasticiser in children s toys is safe. It has also ruled that the current risk assessment models are reliable. Brief details are given in this little article. 

The bioavailability of contaminants to wildlife and humans is also an area of critical importance, where contaminants can be taken up in pore water and by dermal contact, particle ingestion, or particle inhalation. The dynamics of sorption/desorption are not currently incorporated into exposure and risk assessment models for organic compounds, where availability, in most cases, is assumed to be 100% [224]. Recently, the following have been demonstrated and reported ... 

Generally, slow sorption or desorption has made complete remediation technology difficult. However, there have recently been legitimate questions raised by some researchers [163,187] about whether we even need to be concerned about residues that desorb so slowly and thus are apparently largely bio-unavailable. At a minimum, it is important that we understand the factors which govern slow sorption/desorption rates, their kinetics and causes at the intra-particle level of different solid phase materials (e.g., surface/subsurface and aquatic sediment particles), and how these phenomena can relate to contaminant transport, bioavailability, toxicity, remediation, and risk assessment modeling. 

Most scientists would hold that these unknowns and uncertainties in the regulatory risk-assessment model would tend to favor risk overestimation rather than underestimation or accurate prediction. While this view seems correct, it must be admitted that there is no epidemiological method available to test the hypothesis of an extra lifetime cancer risk of about 10 per 1000 000 from methylene chloride in drinking water. The same conclusion holds for most environmental carcinogens. It is also the case that more uncertainties attend the risk assessment process than we have indicated above. 

Regulators in the United States and in Europe, and other public health institutes, appear to have found UF refinements such as those proposed by Renwick to be valuable additions to the risk assessment model for threshold agents, and we should not be surprised to see many examples in the future in which data are judged sufficient to replace the default UFs in just the way we have described. 

Risk Assessment. This model successfully described the disposition of chloroform in rats, mice and humans following various exposure scenarios and developed dose surrogates more closely related to toxicity response. With regard to target tissue dosimetry, the Corley model predicts the relative order of susceptibility to chloroform toxicity consequent to binding to macromolecules (MMB) to be mouse > rat > human. Linking the pharmacokinetic parameters of this model to the pharmacodynamic cancer model of Reitz et al. (1990) provides a biologically based risk assessment model for chloroform. 

The Risk Assessment model comprises (1) prediction of the concentration that will reach the enviromnent (PEC), (2) prediction of the no-effect concentration (PNEC) on a small selection of organisms (3 species), and (3) propose possible minimization measures which will be inserted, in form of standard sentences, in summary of product characteristics (SPC) and/or patient information leaflet of respective Medicinal Product [125]. 

The OECD Database on Chemical Risk Assessment Models includes information on models (computerized or capable of being computerized) that are used by OECD Member governments and industry to predict health or environmental effects (e.g., QSARs), exposure potential, and possible risks. The methods described have not been evaluated or validated by OECD. 

Regional variation in sensitivity or concern for nontarget organisms rors in the structure of risk assessment models Presence of sensitive life stages... 

Risk assessors often encounter situations in which the available datasets may appear, on 1st consideration, to be of limited capacity to support the parameterization of distributions for a given risk assessment model variable. 

An initial step in addressing such situations should be the performance of an analysis of the sensitivity of a risk assessment model to changes in the variable. If the model proves relatively insensitive to conservative bounds to the variable, then further consideration of uncertainty for this variable may be unnecessary and a point estimate may suffice. 

If the risk assessment model is found to be sensitive to the variable in question, a number of options are available to address its parameterization and may include the following ... 

To take a simple case, a pharmaceutical product which is in development may have a tremendous potential value if it reaches the market, but it will have to pass many hurdles before it can generate sales and repay an investment. There are sophisticated risk assessment models which have been produced by Tufts University in the USA and these have become accepted as an industry... 

Electric Power Research Institute. "Air Quality Models Update Decision Frameworks and Risk Assessment Models. Energy Analysis and Environment Division Technical Newsletter, Issue 1. February 10, 1984. 

Organisation for Economic Co-operation and Development [OECD]. 2005b. OECD s database on chemical risk assessment models, http //webdominol.oecd.org/comnet/env/ models.nsf (accessed December 15, 2005). 

Kruizinga, A.G., Briggs, D., Crevel, A., Knulst, A., Van den Bosch, L., and Houben, G.F. 2008. Probabilistic risk assessment model for allergens in food Sensitivity analysis of the minimum eliciting dose and food consumption. Food and Chemical Toxicology 46(5) 1437-1443 doi 10.1016/j.fct.09.109. 

Calculate the transport component of a risk assessment model... 

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