Risk Assessment service

Courtesy: Risk Assessment service

Assessment of risk

The process of risk assessment may be somewhat informal at the individual social level, managing economic and household risks, or a sophisticated process at the strategic corporate level. However, in both cases, ability to anticipate future events and create effective strategies for mitigating them when deemed unacceptable is vital.

At the individual level, a simple process of identifying objectives and risks, weighing their importance, and creating plans, may be all that’s necessary. At the strategic organisational level, more elaborate policies are necessary, specifying acceptable levels of risk, procedures to be followed within the organisation, priorities, and allocation of resources.^: 10 At the systematic level, management involved with the project produce project level risk assessments with the assistance of the available expertise as part of the planning process and set up systems to ensure that required actions to manage the assessed risk are in place. At the dynamic level, the personnel directly involved may be required to deal with unforeseen problems in real time. The tactical decisions made at this level should be reviewed after the operation to provide feedback on the effectiveness of both the planned procedures and decisions made in response to the contingency.

The first step in risk assessment is to establish the context. This restricts the range of hazards to be considered.

This is followed by identification of visible and implied hazards that may threaten the project, and determining the qualitative nature of the potential adverse consequences of each hazard. Without a potential adverse consequence, there is no hazard.

It is also necessary to identify the potential parties or assets which may be affected by the threat, and the potential consequences to them if the hazard is activated.

If the consequences are dependent on dose, i.e. the amount of exposure, the relationship between dose and severity of consequence must be established, and the risk depends on the probable dose, which may depend on concentration or amplitude and duration or frequency of exposure. This is the general case for many health hazards where the mechanism of injury is toxicity or repetitive injury, particularly where the effect is cumulative.

For other hazards, the consequences may either occur or not, and the severity may be extremely variable even when the triggering conditions are the same. This is typical of many biological hazards as well as a large range of safety hazards. Exposure to a pathogen may or may not result in actual infection, and the consequences of infection may also be variable. Similarly, a fall from the same place may result in minor injury or death, depending on unpredictable details. In these cases, estimates must be made of reasonably likely consequences and associated probability of occurrence.

In cases where statistical records are available, they may be used to evaluate risk, but in many cases, there are no data or insufficient data available to be useful. Mathematical or experimental models may provide useful input.

Dose dependent risk

1. Dose-Response Analysis, is determining the relationship between dose and the type of adverse response and/or probability or the incidence of effect (dose-response assessment). The complexity of this step in many contexts derives mainly from the need to extrapolate results from experimental animals (e.g. mouse, rat) to humans, and/or from high to lower doses, including from high acute occupational levels to low chronic environmental levels. In addition, the differences between individuals due to genetics or other factors mean that the hazard may be higher for particular groups, called susceptible populations. An alternative to dose-response estimation is to determine a concentration unlikely to yield observable effects, that is, a no effect concentration. In developing such a dose, to account for the largely unknown effects of animal to human extrapolations, increased variability in humans, or missing data, a prudent approach is often adopted by including safety or uncertainty factors in the estimate of the “safe” dose, typically a factor of 10 for each unknown step.
2. Exposure Quantification, aims to determine the amount of a contaminant (dose) that individuals and populations will receive, either as a contact level (e.g., concentration in ambient air) or as intake (e.g., daily dose ingested from drinking water). This is done by examining the results of the discipline of exposure assessment. As a different location, lifestyle, and other factors likely influence the amount of contaminant that is received, a range or distribution of possible values is generated in this step. Particular care is taken to determine the exposure of the susceptible population(s).

The results of these steps are combined to produce an estimate of risk. Because of the different susceptibilities and exposures, this risk will vary within a population. An uncertainty analysis is usually included in a health risk assessment.