Characterizing the urban exposome in Europe

Background and aim: The EXPANSE project studies the effects of the internal and external exposome on cardiometabolic-pulmonary health of more than 55 million Europeans. The external exposome consists of different environments (built, physico-chemical, social and food) and we aim to apply advance modelling approaches and evaluate and validate geographical data to characterise these different external environments. Methods: The latest advances in mapping and modelling are employed to characterise the external exposome at a fine spatiotemporal resolution across Europe. Geospatial, machine learning and propagation methods are being applied; the most recent remote sensing data are being obtained; validation performed and variables extracted. Results: We completed a first phase of producing several physico-chemical (NO2, PM10, PM2.5 and O3) and built (green, blue, and grey spaces, light at night, and walkability) variables at a high spatiotemporal resolution for 27 EU countries. Specifically, we developed new monthly and annual average concentration maps at a 25*25m resolution between 2000 and 2019, using updated methods to account for spatial heterogeneity improving previous models; built initial models for temperature. Validation of the food environment data showed strong correlation between exposures derived from different data sources, but further quality assessments are still needed. An evaluation of the availability of common social environment variables across Europe is ongoing; we developed a deprivation index at a national level and for some countries at municipality level (Netherland). Conclusions: A range of external exposome variables are available to be assigned to the cohorts included in EXPANSE using the geocoded address location and matching the data of the analysed health event in the different EXPANSE working groups investigating cardio-metabolic and pulmonary health outcomes. The external exposome data will be made publically available at a later stage through the purposely built online tool, Exposome Maps, to facilitate and stimulate exposome research across Europe.