Conservation assessments

Tiered approach a conservative assessment of, particularly, the exposure can be used in the preliminary steps... 

A conservative assessment is unwanted a true measure of the environmental impact is aimed... 

Suter et al. 1993 Society of Environmental Toxicology and Chemistry [SETAC] 1994 European Union 1997 Ecological Committee on FIFRA Risk Assessment Methods [ECOFRAM] 1999 Campbell et al. 1999). The initial use of conservative assessment criteria (i.e., err on the side of caution) allows substances that do not present a risk to be eliminated from the risk assessment process early, thus allowing the focus of resources and expertise to be shifted to potentially more problematic substances or situations. As one ascends through the tiers, the estimates of exposure and effects become more realistic with the acquisition of more accurate and/or representative data, and uncertainty in the extrapolation of effects is thus reduced or at least better characterized. Likewise, the methods of extrapolation may become more sophisticated as one ascends through the tiers (Figure 1.2). 

Analysis in this area gives more conservative assessment of safety than the results obtained through the analysis under the first area in this case the probability of emergency events is assumed equal to 1. However under such approach the obtained numerical estimates are more reliable because the analysis excludes estimates of the probabilities of accident occurrence that is always a rather vulnerable point. 

It would be quite appropriate to draw here an analogy with the generally accepted approach to safety assessment of nuclear power plants where, along with the probabilistic safety analysis, each NPP is calculated for the maximum possible (i.e. beyond the design basis) accident in order to obtain as conservative assessment as possible. 

C.A.M.P. (1998). Selected medicinal plants of northern, northeastern and central India conservation assessment and management plans (CAMP). Forest Department of Uattar Pradesh, Lucknow. 

The MOS values reported in this chapter arc the multiples of the EEC values necessary to reach the respective risk criteria (Table R.6, column 2), based on the appropriate effects values. The MOS values provide a measure of how far the exposure level is from the respective risk criteria. MOS values are discussed below to highlight the gap between the very conservative assessment of risk and the regulatory risk criteria defined by the USEPA. 

The EPP health risk study, which was based on highly conservative assessment criteria, showed that no measurable increase in health risks for workers or the general population in district communities would result from the proposed incineration. 

The Predicted No Effect Concentration may be derived from laboratory, field or theoretical data. Studies conducted on single species such as acute toxicity to fish (IX so) over a relatively short time scale (normally 40 or % h) and with death as the only recorded endpoint is, by itself, only of limited value in deciding whether or not a predicted environmental level of a dye is, or, is not, acceptable. Extrapolation from acute effects to chronic and ecosystems effects involves numerous uncertainties. In order to protect the ecosystem, conservative assessment factors have been introduced based on the statistical analysis of a set of data [17] for chronic exposure. The US-EPA [18] has proposed to apply a factor of KXX) for a single acute L(E)Cso value or 100 to the lowest value if all 3 tests are available (fish, daphniae, algae). These models have in common that they assume steady state concentrations in the aquatic environment. 

Creative but Conservative. Finding new and economical solutions to civil engineering problems requires a creative mind that thinks beyond the accepted and regular practices, but the reliability and safety of the created product requires a conservative assessment in every aspect, because for every civil engineering product, failure is not an option. 

If there are differences in the working conditions between the component to be assessed and the one which has been observed it has to be examined to what extent these working conditions are encountered in any of the observed plants. An analysis of dependencies is helpful in this context. For example, generally reliability data of components exposed to aggressive media are worse than those to be expected in case of exposure to water. They then may serve as conservative estimates. The same is tme for cases of strong mechanical loads like, for instance, strong vibrations. Values obtained for such cases may also serve as conservative assessments for components under normal loads. 

If the compartment specific fire load density exceeds 90 MJ/m2 and a conservative assessment provides a value of Fhs,(comp) of less than 1.0 E-07/a for this compartment, no detailed, realistic calculation is required for this compartment. (The decision criterion of 1.0 E-07/a must be modified, if the summarized frequencies of fire induced hazard states of all compartments with Fhs,comp < 10 E-07/a exceeds 1 % of the frequency estimated for all compartments). 

If the conservative assessment provides a value for Fhs,comp exceeding 1.0 E-07/a, the frequency of fire induced plant hazard states must be calculated in detail for the corresponding eompartment. 

Li order to conservatively assess the damage fi-om the draindown event, the feOowing concerns were addressed ... 

Criticality safety analysis is a discipline aimed at the prevention or termination of inadvertent nuclear chain reactions in nonreactor environments. Although the physics and mathematics are the same as for reactor analysis, the basic approach is different because the goal is different. Because the analysis goal of criticality safety exclusively is to establish a conservative assessment of the criticality state of a given proposed operation, and the systems being analyzed have so much variety, the methodology takes a completely different form than reactor analysis methodology. 

This represents a conservative assessment for the following reasons ... 

Another variable is the area of area of skin that can come in direct skin contact with these surfaces. Some of the original work on this issue was done by the New York State Department of Health. Under the New York State method, the activity is evaluated as to exposure potential and the surface area in cm specified for individuals and tasks. Assessments are then made as to the percent of uptake off surfaces. Empirical evidence suggest that 80-90% of the surface PCB contamination can be removed by wiping a surface with a hexane saturated wiping cloth. It is thus seen as a very conservative assessment that the dry skin of the hand would have significantly less uptake efficiency. Variations on this uptake efficiency can significantly vary the outcome. 

Dinerstein, E. et al., A conservation assessment of the terrestrial ecoregions of Latin America and the Caribbean, World Bank, Washington, D.C., 1995. 

Canister stress and stability analyses have shown that a canister suffering pitting corrosion to a depth of 50 mm will still survive the maximum external isostatic pressure of 30 MPa (Steag Motor Columbus 1985), indicating that the conservative assessment of 30 mm canister corrosion in 1000 years still leaves a high margin of safety in the design. 

In this case, the accuracy of the assessment method used should be adjusted to the desired goal. For instance, an approximate, yet conservative, assessment method is sufficient to demonstrate the adequacy of the existing structural system against vertical loads. When the existing structural system is apparently inadequate and is expected to be fully demolished, its assessment is not necessary. 

Figure 2.2 (A-C) Hypothetical relationships bettveen utility, effort and completeness for species inventory (grey curves) and conservation assessment (black curves). Figure adapted tvitb permission from Green et al. (2005).

The next stage of guide preparation involved using the databased specimen information to calculate provisional conservation assessments. A GIS programme, ArcMap, was used to create distribution maps for each species, with individual localities represented as points. These data were used to calculate two measures of range size, the Extent of Occurrence and the Area of Occupancy, used to determine threat rating thresholds in International Union for the Conservation of Nature... 

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