Pollutants such as lead, cadmium and arsenic potentially pose a threat to our health, even at low levels of exposure. Exposure before birth and in childhood may have particularly important damaging effects on the developing lungs, brain and cardiovascular system. In this project we plan to measure these pollutants in maternal urine samples taken during pregnancy and in blood samples from the offspring in childhood to see whether levels are higher in mothers and children who are less well off, and whether higher exposure before birth and/or in childhood is associated with poorer lung function, higher blood pressure, and lower IQ and educational attainment in childhood. If these pollutants are affecting children's health, they might be contributing to the poorer health seen in less well off children.