Andhra Pradesh Children and Parents Study (www.apcaps.lshtm.ac.uk) is a cohort of households which took part in a mother-child nutritional supplementation trial (1987-90). Located in vicinity of Hyderabad city, an emerging technology hub in south India, the study district is undergoing rapid uneven urbanisation, providing a unique window of opportunity (analogous to a stepped-wedge design) to investigate of health effects of urbanisation. So far, we have collected data on built environment and air quality of study villages, and serial longitudinal data for chronic disease risk factors on cohort participants (n=7000). We now propose to expand clinical data collection, on a wide range of health outcomes (e.g. chronic diseases, mental health, ageing, injuries, infectious diseases), making extensive use of wearable sensors and other digital technologies, to all remaining residents (N=100,000) of the 29 study villages. The resulting Urbanising Population Laboratory – a complete eco-system of health data, including bio-repository, on all individuals, their inter-relationships/networks, and their environment (natural, physical, social) – set within a backdrop of rapid uneven urbanisation, will offer the global research community unparalleled opportunities to investigate how environment shapes human health. We will establish a linked electronic health surveillance system to enable ongoing data collection. Collaboration with an established LPS (ALSPAC) will add further value to both cohorts.