“…there is no time for delay and no room for excuses.” (Antonio Guterres, United Nations Secretary-General, August 9, 2021 [1])

The summary of the 6th Assessment Report (6AR) of the Intergovernmental Panel on Climate Change [2] indicated once more that sea levels continue to rise, and extreme weather patterns are the main climate change-related threats to human health and the environment. Disasters related to extreme weather events, wildland fires, and outbreaks of infectious disease, and industrial accidents are increasingly impacting community wellbeing and population health.

Exposure science is advancing to support disaster preparedness, emergency response, and mitigation of impacts in the after math of both man-made and natural disasters [3]. Contributions in this special topic issue address exposures across temporal and geographical dimensions for a range of natural and man-made disasters. Reported results consider exposure and health impact information collected in an early phase by search and rescue teams, during the incident from victims and existing monitoring systems, as well as during the aftermath.

The safety of first responders is assessed prior to entering the affected area for search and rescue (S&R) operations. This assessment is the first opportunity to collect data for exposure and risk assessment. In general, exposure assessment for the S&R activity requires swift and timely results to support on-scene commanders and coordinators. Once the first responders are active in the disaster area they collect and share additional information via situation reports and visual recordings such as videos from drones.

Exposure data is vital to enable modelling for mitigation of the impact in emergency settings, e.g. Computer-Aided Management of Emergency Operations (CAMEO). For hazardous substances an atmospheric dispersion model can be used for evaluating releases of hazardous chemical vapours (ALOHA). This software can be used to generate plots that indicate the perimeter of a threat zone with guidance values such as the Acute Exposure Guideline Levels for Airborne Chemicals (AEGLs) and the Emergency Response Planning Guidelines (ERPGs) in the US. The accuracy of these model predictions is limited and the perimeter of the affected area needs verification by observations and measurements by S&R teams in field.

In addition to information from the first responders, data from existing networks of weather stations are of particular interest during extreme weather events. Regular air monitoring networks provide air quality parameters that may be important for urban areas covered by smoke from wildland fires [4]. These data can be complemented by data from remote sensing systems that generate space and time-resolved data on the impact of large-scale incidents [5, 6]. In extreme events such as massive hurricane or tsunami, blackout of electricity in the affected area can be anticipated. Then, a self-supporting mobile laboratory or aircraft such as Portable High-Throughput Integrated Laboratory Identification System (PHILIS) and Airborne Spectral Photometric Environmental Collection Technology (ASPECT) may play an important role for rapid exposure measurements.

When the acute phase is over, additional data may be collected during the aftermath. Examples of relevant data are related to air quality [7], surface, drinking water, and crop contamination. Health outcomes are studied using different types of outcomes, e.g. reports of emergency room visits, hospital admissions and reports of type and severity of injury, including initial counts of fatalities and missing persons. During the aftermath data may also be collected through crowd research and plotted for the locations from which health complaints are reported.

More detailed quantitative exposure data are most likely not collected until later. Human biomonitoring is a good method for chemical exposure surveillance of first responders like firefighters who respond to chemical incidents in industrial settings [8] or more general settings [9]. Human biomonitoring campaigns may also be used to confirm exposures in a larger group of disaster victims specifically when measurements in environmental compartments are not possible or come too late [10, 11]. Recently, the Joint Research Center published a flagship report to describe how science informs disaster management [12]. Many exposure-related topics were highlighted as innovations such as human biomonitoring to support emergency response to disasters [13].

During the aftermath of a disaster there may be long-term effects on human health and the environment. The study population is usually defined by survivors still at risk living in the affected area or by those that evacuated themselves or have been evacuated from the disaster area but could still be linked to the disaster e.g., by analysing registries of emergency rooms in healthcare facilities. Exposure and health-oriented studies require additional data collection and modelling to link recruited individuals to locations in the disaster area as verification of their exposure status [14]. When interpreting the impact on humans and the environment it is often difficult to tell which part of the observed impact can be attributed to the disaster, in addition to a history of events also including residues from previous disasters, e.g. during previous floods or other causes in the same area [15]. Registrations of exposure status by the reported health complaints can be inaccurate especially if the complaints are non-specific to the source of exposure. Available biomonitoring data can be useful to verify exposure status and show that hospital visits may provide very limited justification for classification of exposure [16].

For the future, the relevance of exposure assessment is well recognised. The European Commission considers exposure science already in an early phase of emergency response to transboundary disasters by including exposure scientists to an expert panel with a wide range of disciplines relevant to disaster scenarios. In the case of a large incident with cross-border effects, a team with expertise considered relevant to the scenario analyses the situation and provides a rapid risk assessment report to the European Commission to support decision making how to provide support related to transboundary aspects [17, 18].

In conclusion, exposure science is essential for effective disaster preparedness and response. Exposure scientists are encouraged to collaborate broadly across sectors to advance exposure assessment methods and technologies as well as surveillance and monitoring.