Qualitative risk assessment consequence evaluation

Abstract. Environmental risk assessment evaluates the quantitative and qualitative characteristics of the environment, in order to highlight the risk on environment and human health due to the potential presence or use of specific pollutants. Risk is a probability of an adverse direct or indirect effect, on the environment or human health. It is a combination of the probability of occurrence of an event and the possible extent of that event s adverse effects and consequences, in terms of adverse effects on the ecosystem and human injury. Risk is defined as the probability of an event to occur, related to the seriousness and extent of its consequences. An environmental risk assessment should be conducted, by adopting a systematic approach, when it is determined that a management action may have consequences to either the state of the environment or human health or well-being. 

Safety analyses principally comprise qualitative Hazard Analysis and probabilistic Safety Risk Assessment. Hazard Analysis models and evaluates the system s hazardous conditions and related system functions in order to identify the possible hazardous consequences which may occur as the result of initiating events such as failures or environmental aggressions. Probabilistic Safety Risk Assessment evaluates the... 

It is one of the aims of the lUPAC project to qualitatively and quantitatively assess the impact of altered pesticide use on GM crops. Furthermore, otho impacts will also be taken into account, which may include weed eeology and soil conservation. Finally a risk-benefit analysis of these impacts will be made by evaluating the various outcomes of our research, which may provide a tool for further polieies in the area of GM crop cultivation and pest management. This is an important endeavour given the public concerns regarding large scale cultivation of GM crops and its environmental consequences. 

Qualitative analysis of risk is a subjective measure, based upon the risk assessor s judgement. As with all methods of risk evaluation, a qualitative assessment will need to allow consideration of the two aspects of risk, i.e. the likelihood of a particular occurrence and the severity of the consequences. 

A common method employed in qualitative safety artalysis is the use of a risk matrix method (Halebsky (1989), Tummsda and Leung (1995)). The two parartreters that are considered are the occurrence likelihood of the failure event and the severity of its possible consequences. Upon identifying all the hazards within the system under consideration, each hazard is evaluated in terms of these two parameters. The severity of all the failure events could be assessed in terms of the four categories (i.e. Negligible, Marginal, Critical and Catastrophic) as shown in Table 3.1. 

---