Policy Making and Uncertainty

Public policy issues are:

  • Complex, occurring in rapidly changing and turbulent environments characterized by uncertainty; and
  • Involve conflicts among different interests.

Those responsible for creating, implementing, and enforcing policies must be able to reach decisions about ill-defined problem situations that usually are not well understood, do not have a single correct answer, and involve many competing interests.

Risk Management and Precautionary Principle

Policy makers and risk managers will always deal with constraints, including limited and incomplete information.

The Precautionary Principle (Principle 15, Rio Declaration, 1992) provides guidance for protecting public health and the environment in the face of uncertain risks. The precautionary principle states that the absence of full scientific certainty shall not be used as a reason to postpone measures where there is a risk of serious or irreversible harm to public health or the environment.

The precautionary principal includes two key elements:

  • Decision-makers need to anticipate harm before it occurs. It is the responsibility of the proponent to establish that the proposed activity will not (or is very unlikely to) result in significant harm;
  • The need for control measures increases with both the level of possible risk and the degree of uncertainty.

Removing Uncertainty

  • Scientific uncertainties, assumptions and other limitations will be identified during the decision-making process.
  • Estimate level of risk within a precautionary approach.
  • The tendency to over- or under-estimate the risks should be clearly evaluated.
  • Decision makers have to consider the most sensitive sub-group, since variability of exposure within individuals and between sub-groups can be a significant issue.


PCBs can enter the human body through numerous pathways.  Using the precautionary principle all of these pathways would be accounted for when specific exposure information is not known.

The absence of full scientific certainty shall not be used as a reason to postpone measures where there is a risk of serious or irreversible harm to public health or the environment
Source: Thierry Caro
Hatfield Consultants The World Bank funded by the Canadian POPs Trust Fund through the      
Canadian International Development Agency
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