Characterization of the world population’s exposomes

Environmental variables such as air pollution, noise, floods, green space and conflict , shape human health and disease. An important concept is the human exposome, the totality of an individual’s exposure to the environment over their lifetime. The exposome can explain a large proportion of our health, yet quantification across the world population remains surprisingly limited. As we are facing global climate and population change, it becomes increasingly important to understand and quantify the exposome. However, existing studies are often small-scale, do not integrate human mobility affecting personal exposure or focus on narrow sets of variables, thereby failing to capture the full range of socioeconomic and physical variables and values. Harmonized global scale quantitative assessments of the entire exposomes of the world population remain limited.  We address this by collecting data sets on environmental variables for a wide range of geo-domains at high resolution (<= 1-10 km²) with global coverage. Seven geo-domains characterizing the external exposome were defined: meteorological and hydrological, biological, geological, air, soil, technological (built environment), and societal.  Human mobility in tandem with differing exposure pathways (e.g. passive, through inhalation vs. active, by selecting food stores) are represented globally by aggregating exposures within the spatial context of individuals. The relevant spatial context is an area surrounding the residential locations. Exposure values are first calculated in distance rings centred at the residential location and then aggregated using distance dependent weights. The function determining the weight and maximum distance depends on the exposure pathway and, following this, the relevant human mobility characterization for exposure. To this harmonized dataset, population density is attributed, producing a characterization of the global exposome that will be catalogued in the Green Deal Data Space (GDDS). Initial harmonized processing is executed for global datasets on tropical cyclones, earthquakes, and riverine and coastal flooding, showing hazard intensity and human exposure have different spatial patterns. For example, populated coastal and riverine regions are substantially exposed to flooding relative to their physical hazard extent, whereas other hazards leave populations unaffected. These emerging contrasts illustrate the importance of harmonized global exposome characterization. The assessment framework lays a foundation for analyses on co-exposures, spatial patterns and equitable public health strategies.