Impact evaluation case examples

In many cases, it is not readily apparent how the potential impacts from different hazards can be translated into some common scale or measure. For example, how do you compare long term environmental damage and health risks from use of CFG refrigerants to the immediate risk of fatality from the fire, explosion, and toxicity hazards associated with many alternative refrigerants This question does not have a right answer. It is not really a scientific question, but instead it is a question of values. Individuals, companies, and society must determine how to value different kinds of risks relative to each other, and base decisions on this evaluation. 

The theoretical examples supplied should give the reader an idea what kind of costs may be considered in case Chemical Leasing is evaluated before implementation. Main purpose is to show how "fair sharing of added-value" can be realised and what kind of factors have major impacts. 

Exposure may take place at one point in space and time, but effects may not arise until another place or time. Both life history characteristics and the circumstances of exposure influence susceptibility in this case. For example, exposure of a population to endocrine-modulating chemicals can affect the sex ratio of offspring, but the population impacts of this exposure may not become apparent until years later when the cohort of affected animals begins to reproduce. Delayed effects and multiple stressor exposures add complexity to evaluations of susceptibility. For example, although toxicity... 

Annex 1 provides a case-study of a qualitative characterization of uncertainties in an exposure assessment. Table A1.2 in Annex 1 details the evaluation throughout the three-dimensional characteristics. Included is an overall conclusion on sensitivity—that is, those aspects that have the most significant impact on the outcome of the assessment, as better data collected on these features would considerably reduce the measure of uncertainty. An example of the overall conclusion is given in section A 1.5 of Annex 1. The main uncertainties identified in the assessment are tabulated, as illustrated in Table 5, and a brief explanation of the weights given to them in reaching an overall conclusion is provided. In addition, a textual description of the qualitative characterization of tabular output should include an indication of overall uncertainty, based on the collective impact of each of the sources. 

The variety of reactions which have been described indicate the large number of chemical species which enter in the troposphere and which may have an impact upon the environment. It is necessary to emphasize that all species are in a dynamic equilibrium for the meteorological turbulence so that in some cases redox and acid-base reactions occur with the formation of stable compounds with high formation constants but nevertheless the reagent species are detectable in the atmosphere. A typical example is the evaluation of the atmospheric aerosol where besides the presence of ammonium sulphates, free ammonia and sulphuric acid may coexist. 

In the dilution experiments, on which the aroma models are based, the odour impact of the volatiles is evaluated after separation by GC (cf. 6.2.4.2.2). Perceptual interactions of odorants, which in most cases were characterised by inhibition and suppression [8, 36], are excluded by this procedure. Therefore, the question as to which compound among the volatiles evaluated by the dilution experiments actually contributes to the aroma has to be answered by omission experiments (step 7 in Table 6.23). Examples of such experiments are given in 6.2.4.3. 

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