The purpose of this article is to describe the system established in France to ensure effective handling of environmental health inquiries, which, in some cases, require an urgent response. In this field, several ministries, agencies, and public bodies are involved, given the wide range of environmental health issues. Whether the initial signal is environmental, health-related, or societal, the various public health stakeholders coordinate their efforts to provide, within a timeframe appropriate to the situation, the necessary response to control the situation and minimize its health impact as much as possible. (R.A.)