AIM - This four year study will examine longitudinal associations of road traffic noise exposure and air pollution on the development of children's cognition, cardiovascular health and psychological wellbeing in the ALSPAC (Avon Longitudinal Study of Parents and Children) cohort. This study will model environmental exposure relating to noise and air pollution in the home and school environments in the ALSPAC databases using established, validated modelling methods, for different time-points across childhood (prenatal, preschool, childhood, adolescent). This environmental exposure modelling will enable the examination of longitudinal associations and critical periods for noise exposure and air pollution effects on children's cognition, health, and wellbeing to be examined. The influence of environmental noise and air pollution on the developmental trajectories for these outcomes will also be examined.