Exceptional Public Health Situations

In the event of an exceptional public health situation, Santé publique France assesses the health consequences for exposed populations in order to guide the management measures implemented by public health authorities.

Exceptional public health situations (EPS)—whether caused by environmental factors (industrial disasters, extreme weather events) or infectious agents (epidemics, pandemics)—disrupt people’s daily lives and test the resilience of regions. Managing them goes beyond standard alert procedures and requires a rapid, coordinated, and scientifically grounded response.

EPHs can be caused by:

An exceptional public health situation is characterized by:

  • its scale: it may affect or even impact a group of municipalities, one or more departments, one or more regions, the entire national territory, or even include neighboring territories or those beyond;
  • its origin: it may be natural, exacerbated by climate change or human activity, or both;
  • its dynamics: it is generally sudden, unexpected, and evolves over time and space;
  • its media coverage, whether actual or potential.

As part of its missions, Santé publique France relies on mapping of exceptional environmental situations to assess their consequences for public health.

What are Santé publique France’s responsibilities in responding to exceptional environmental situations?

An exceptional environmental situation may be caused by human activity or natural phenomena and pose specific risks to people, property, and the environment, requiring appropriate response measures.

The agency’s mission is to anticipate and assess health impacts and to support authorities in decision-making by drawing on its scientific expertise, its regional presence, and its partners. 

In the event of an exceptional environmental situation, Santé publique France’s tasks are to rapidly assess the event’s impact on the physical and mental health of the population and to provide logistical and scientific support to health authorities. This assessment should enable:

  • Early detection of a health phenomenon and issuance of an alert regarding its occurrence.
  • To characterize and quantify the event’s impact on health.
  • To identify and characterize at-risk populations.
  • To provide support for implementing the response plans necessary to protect the population.

Depending on the nature of the event, Santé publique France may also activate several measures:

  • Mobilizing the Health Reserve: a pool of healthcare professionals and experts ready to step in as reinforcements to support local teams, strengthen response capabilities, and ensure optimal care for affected populations.
  • Support from the Pharmaceutical Agency: to guarantee access to the necessary pharmaceutical and logistical resources (strategic stockpiles of health products, distribution of treatments, etc.).

What are the potential health effects of exceptional environmental conditions?

Health effects (or health impacts) are changes in the health status of an individual or a population caused by exposure to an environmental factor (pollution, chemicals, etc.) associated with an event. These effects can be direct—that is, directly linked to the event itself—or indirect—that is, linked to a chain of events. They are often delayed, complex, and multifactorial.
Depending on the duration of exposure for the population and the latency period between exposure and the expected health effects, we distinguish between:

  • Short-term effects of immediate exposure: these are the acute and immediate effects observed at the time of the event and within the following month;
  • Medium- and long-term effects of immediate exposure: these are delayed effects that occur some time after the event, more than one month after the event and up to several years later;
  • Long-term effects of chronic exposure: these are effects associated with continuous and repeated exposure over a long period that may occur if the population is overexposed to toxic compounds released into and deposited in the environment during the event.
     

What types of measures are being implemented?

Analyzing the impact of short-term effects on public health 

As a first step, the analysis of the short-term health impacts on the population will rely on existing epidemiological surveillance systems that Santé publique France can directly mobilize in collaboration with its partners. These systems may be supplemented by additional measures to strengthen the response provided to local authorities.

In the hours immediately following an event, Santé publique France will thus rely on:

The SurSaUD® syndromic surveillance system, coordinated by Santé publique France in collaboration with hospital emergency departments (the OSCOUR® network), the SOS Médecins associations, as well as INSEE and Inserm-CépiDc for mortality data.

  • Objective: To analyze the use of emergency care on the day of the accident and in the days that followed. 
  • Methodology: Data provided in near real time, enabling verification of whether a change in healthcare utilization is observed following the event, particularly in emergency departments and at SOS Médecins clinics.
  • Data collected/monitored: daily number of emergency department visits and visits and consultations provided by SOS Médecins; syndrome-based groupings derived from the primary and associated diagnoses recorded for each patient (including indicators related to the digestive, respiratory, cardiovascular, infectious, and mental health systems).
  • Advantages: an initial rapid assessment of acute effects requiring urgent medical care to guide or adapt management measures, particularly in the immediate aftermath of the accident.
  • Limitations: Data is limited to emergency care (hospital emergency departments and SOS Médecins); it does not account for cases resulting from self-medication or care pathways that do not involve emergency care.

Depending on the nature of the event, Santé publique France may rely on local support structures such as medical-psychological emergency response teams (CUMP), advanced medical posts (PMA), ongoing contingency plans (DPS), coordinated by various civil protection and healthcare providers, or the Poison Control and Toxicovigilance Centers (CAPTV).

  • Objective: to collect information and data to supplement the description of public health events and the affected population monitored through the SurSaUD® system.
  • Data collected/monitored: number of deaths, injuries, or people receiving care…
  • Benefits: Data collection as close as possible to the event and in the prehospital setting to guide or adapt management measures, particularly in the immediate aftermath of the accident.
  • Limitations: Data is limited to support facilities.

Assessing Medium- and Long-Term Risks and Impacts

While data from the surveillance systems activated as a first response provide an initial snapshot of the use of emergency care or first aid, it may be necessary, within the first few hours of the event, to survey the population to describe the health impacts as a supplement to the data directly available. 

  • In such cases, Santé publique France may propose, in collaboration with local authorities and local health stakeholders, the implementation of: 
  • a census of individuals to participate in a potential perceived health survey, particularly to assess any adverse effects and symptoms experienced in connection with the accident;
  • a survey of healthcare professionals to characterize the physical and mental health impacts among patients seen in clinical practice;
  • cross-sectional health surveys of the exposed population, which may be repeated over time to monitor changes in their physical and mental health over a defined period;
  • surveys of vulnerable or specific populations (e.g., pregnant women, children, workers). 

The relevance of implementing accident-specific biological monitoring (blood and urine sampling) and its feasibility may be assessed by Santé publique France at the request of health authorities. This system for assessing exposure to pollutants is the subject of a dedicated methodological guide.

These surveys can be proposed and implemented as early as the emergency phase, at the start of the post-accident phase, or after the event.

Example of a population-based survey:

Provide information on the methods used and the health impacts of exceptional situations

During a public health crisis, providing information and engaging in dialogue with affected communities are top priorities. Santé publique France is committed to:

  • make information accessible to everyone: we ensure that our analyses and recommendations are public, clear, and understandable, whether for public decision-makers, affected populations, or local stakeholders (healthcare professionals, local governments, organizations, etc.);
  • explain our methods and their limitations: with full transparency, we detail our assessment and surveillance methods and clarify the uncertainties associated with the data or scientific knowledge consulted;
  • feedback the results to local communities: we gather feedback from residents and local stakeholders to help tailor actions to the needs expressed;

A collaborative approach for an effective and tailored public health response.