Who defines the question ?

Questions about potential health impacts from the environment may arise in different ways, and from different sources.

For example:

• Policy-makers may ask ‘What will be the effects of this policy’, or ‘How well are our current policies working’?
• Scientific studies may suggest that specific substances or practices pose a risk to health, which merit investigation.
• Long-term monitoring of the environment or of health may show patterns or trends that give cause for concern.
• Practitioners (e.g. doctors), the media or members of the public may believe that they have observed anomalous patterns or trends (e.g. disease clusters or growing rates of illness) that imply some form of environmental threat to health.

Each of these may merit some form of impact assessment, and if the issues are complex or have wide-ranging implications then an integrated assessment may be appropriate. However, the opportunity actually to undertake an assessment may vary greatly. For example, while policy-makers usually have the authority to commission an assessment, and scientific evidence (if validated by repeated studies) are often powerful enough to motivate action, the costs and complexities involved may limit the ability of members of the public to have an issue assessed in any formal way. How the question originates may greatly condition the type of assessment that is done (and the sorts of issues that are addressed)