What must be done before a health risk assessment is conducted?

Obtaining informed consent from affected individuals or populations is crucial before conducting a health risk assessment because it ensures that those involved are fully aware of the assessment's purpose, procedures, and potential risks. This consent respects the autonomy of individuals and aligns with ethical standards in public health practice. It allows participants to make an informed decision about their involvement in the assessment, fostering trust and cooperation between health professionals and the community.

The other options, while they may be important in different contexts, do not take precedence over the necessity of informed consent. Notifying local authorities might be relevant, but it does not pertain directly to the rights of the individuals being assessed. Conducting preliminary surveys and gathering existing health data can provide valuable background information, but these steps do not replace the need for consent and ethical considerations regarding individual participation in the assessment.