Previous studies exploring the influence of the urban environment on later blood pressure have mostly focused on single exposures, or a specific, related group of exposures, and have assessed the influence on blood pressure at specific ages. However, we are simultaneously and cumulatively exposed to various environmental exposures, including air pollution, traffic, noise, natural spaces, built environment, food environment, meteorological factors and social deprivation. Therefore, further research using a more holistic view of the urban environment and assessing the longitudinal association with blood pressure using repeated measures is needed. This project will use an exposome approach to understand how a range of urban environmental exposures during pregnancy and childhood influences changes in children's blood pressure from birth to 18 years old. We will analyze data from up to 18 different cohort studies, including up to 74,000 participants.