ACTUAL ("Advancing research on extreme humid heat and health") aims to advance knowledge about the impact of humid heat on human health through developing, diversifying, and applying new methodologies, data resources, and settings beyond existing current state-of-the-art approaches in climate epidemiology.
Led by Ana M. Vicedo-Cabrera, it is a SNSF Starting Grant 2022 project funded with 1.7 million CHF for 5 years, starting in June 2023.
Extreme heat is considered among the most hazardous environmental factors for human health. From the perspective of human physiology, hot temperatures are particularly harmful with concurrent high humidity. In the epidemiological literature, however, the role of humidity as a driver of heat stress remains unclear, and even debatable based on the contradictive findings obtained so far. Clarifying inconsistencies in the temperature-humidity-health triangle and providing reliable, robust scientific evidence on the impact of humid heat among populations is urgently needed to efficiently address health-related challenges from climate change. ACTUAL seeks to clarify these inconsistencies through a series of case studies or experiments which were carefully designed to answer the following questions: Is temperature enough to capture the effect of heat stress? or should we consider humidity as well? and, in which settings or populations?
Case study 0 provide a theoretical framework showing the links between temperature, humidity and health that will support the design of three large epidemiological studies. See our recent publication led by Sidharth Sivaraj on causal diagrams and heat-humidity-health nexus.
In case study 1, the team is using a probabilistic framework to compare excess mortality estimates at extremely humid and dry heat events.
In case studies 2 and 3, the team will derive vulnerability profiles to humid heat by summarizing risks from mortality and hospitalization data from a worldwide database, and from data collected through commercial wristbands, respectively.
Finally, case study 4 aims to assess the impact of humid heat on health among a high-risk population, specifically the city of Basse Santa Su (The Gambia in Sub-Saharan Africa), in collaboration with MRC Gambia-LSHTM unit. The project team has already started collecting data in the study site and will run until December 2025.
